The influence of minimalist footwear and stride length reduction on lower-extremity running mechanics and cumulative loading.

PubMed

Firminger, Colin R; Edwards, W Brent

2016-12-01

To examine the effects of shoe type and stride length reduction on lower-extremity running mechanics and cumulative loading. Within-subject with four conditions: (1) control shoe at preferred stride length; (2) control shoe at 90% preferred stride length; (3) minimalist shoe at preferred stride length; (4) minimalist shoe at 90% preferred stride length. Fourteen young healthy males ran overground at their preferred speed while motion capture, force platform, and plantar pressure data were collected. Peak moments, impulse, mechanical work, and cumulative impulse were calculated at the metatarsophalangeal, ankle, and knee joint, and compared between conditions using a 2×2 factor repeated measures ANOVA. In general, running in minimalist footwear increased measures of loading at the metatarsophalangeal joint and ankle joint (mean increases of 7.3% and 5.9%, respectively), but decreased measures of loading at the knee (mean decrease of 7.3%). Conversely, running with reduced stride length decreased single-stance measures of loading at the ankle and knee joint (ranging from -0.9% to -20.5%), though cumulative impulse was higher at the ankle and lower at the knee. Running in minimalist shoes increased loads at the metatarsophalangeal and ankle joint, which may explain some of the incidence of overuse injuries observed in minimalist shoe users. Decreased ankle loads at 90% preferred stride length were not necessarily sufficient to reduce cumulative loads when impulse and loading cycles were weighted equally. Knee loads decreased more when running at 90% preferred stride length (16.2% mean reduction) versus running in a minimalist shoe (7.3% mean reduction), but both load reduction mechanisms appeared to have an additive effect (22.2% mean reduction). Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

The desert ant odometer: a stride integrator that accounts for stride length and walking speed.

PubMed

Wittlinger, Matthias; Wehner, Rüdiger; Wolf, Harald

2007-01-01

Desert ants, Cataglyphis, use path integration as a major means of navigation. Path integration requires measurement of two parameters, namely, direction and distance of travel. Directional information is provided by a celestial compass, whereas distance measurement is accomplished by a stride integrator, or pedometer. Here we examine the recently demonstrated pedometer function in more detail. By manipulating leg lengths in foraging desert ants we could also change their stride lengths. Ants with elongated legs ('stilts') or shortened legs ('stumps') take larger or shorter strides, respectively, and misgauge travel distance. Travel distance is overestimated by experimental animals walking on stilts, and underestimated by animals walking on stumps - strongly indicative of stride integrator function in distance measurement. High-speed video analysis was used to examine the actual changes in stride length, stride frequency and walking speed caused by the manipulations of leg length. Unexpectedly, quantitative characteristics of walking behaviour remained almost unaffected by imposed changes in leg length, demonstrating remarkable robustness of leg coordination and walking performance. These data further allowed normalisation of homing distances displayed by manipulated animals with regard to scaling and speed effects. The predicted changes in homing distance are in quantitative agreement with the experimental data, further supporting the pedometer hypothesis.

Differential effects of absent visual feedback control on gait variability during different locomotion speeds.

PubMed

Wuehr, M; Schniepp, R; Pradhan, C; Ilmberger, J; Strupp, M; Brandt, T; Jahn, K

2013-01-01

Healthy persons exhibit relatively small temporal and spatial gait variability when walking unimpeded. In contrast, patients with a sensory deficit (e.g., polyneuropathy) show an increased gait variability that depends on speed and is associated with an increased fall risk. The purpose of this study was to investigate the role of vision in gait stabilization by determining the effects of withdrawing visual information (eyes closed) on gait variability at different locomotion speeds. Ten healthy subjects (32.2 ± 7.9 years, 5 women) walked on a treadmill for 5-min periods at their preferred walking speed and at 20, 40, 70, and 80 % of maximal walking speed during the conditions of walking with eyes open (EO) and with eyes closed (EC). The coefficient of variation (CV) and fractal dimension (α) of the fluctuations in stride time, stride length, and base width were computed and analyzed. Withdrawing visual information increased the base width CV for all walking velocities (p < 0.001). The effects of absent visual information on CV and α of stride time and stride length were most pronounced during slow locomotion (p < 0.001) and declined during fast walking speeds. The results indicate that visual feedback control is used to stabilize the medio-lateral (i.e., base width) gait parameters at all speed sections. In contrast, sensory feedback control in the fore-aft direction (i.e., stride time and stride length) depends on speed. Sensory feedback contributes most to fore-aft gait stabilization during slow locomotion, whereas passive biomechanical mechanisms and an automated central pattern generation appear to control fast locomotion.

Evaluation of the microsoft kinect skeletal versus depth data analysis for timed-up and go and figure of 8 walk tests.

PubMed

Hotrabhavananda, Benjamin; Mishra, Anup K; Skubic, Marjorie; Hotrabhavananda, Nijaporn; Abbott, Carmen

2016-08-01

We compared the performance of the Kinect skeletal data with the Kinect depth data in capturing different gait parameters during the Timed-up and Go Test (TUG) and Figure of 8 Walk Test (F8W). The gait parameters considered were stride length, stride time, and walking speed for the TUG, and number of steps and completion time for the F8W. A marker-based Vicon motion capture system was used for the ground-truth measurements. Five healthy participants were recruited for the experiment and were asked to perform three trials of each task. Results show that depth data analysis yields stride length and stride time measures with significantly low percentile errors as compared to the skeletal data analysis. However, the skeletal and depth data performed similar with less than 3% of absolute mean percentile error in determining the walking speed for the TUG and both parameters of F8W. The results show potential capabilities of Kinect depth data analysis in computing many gait parameters, whereas, the Kinect skeletal data can also be used for walking speed in TUG and F8W gait parameters.

Effects of different frequencies of rhythmic auditory cueing on the stride length, cadence, and gait speed in healthy young females.

PubMed

Yu, Lili; Zhang, Qi; Hu, Chunying; Huang, Qiuchen; Ye, Miao; Li, Desheng

2015-02-01

[Purpose] The aim of this study was to explore the effects of different frequencies of rhythmic auditory cueing (RAC) on stride length, cadence, and gait speed in healthy young females. The findings of this study might be used as clinical guidance of physical therapy for choosing the suitable frequency of RAC. [Subjects] Thirteen healthy young females were recruited in this study. [Methods] Ten meters walking tests were measured in all subjects under 4 conditions with each repeated 3 times and a 3-min seated rest period between repetitions. Subjects first walked as usual and then were asked to listen carefully to the rhythm of a metronome and walk with 3 kinds of RAC (90%, 100%, and 110% of the mean cadence). The three frequencies (90%, 100%, and 110%) of RAC were randomly assigned. Gait speed, stride length, and cadence were calculated, and a statistical analysis was performed using the SPSS (version 17.0) computer package. [Results] The gait speed and cadence of 90% RAC walking showed significant decreases compared with normal walking and 100% and 110% RAC walking. The stride length, cadence, and gait speed of 110% RAC walking showed significant increases compared with normal walking and 90% and 100% RAC walking. [Conclusion] Our results showed that 110% RAC was the best of the 3 cueing frequencies for improvement of stride length, cadence, and gait speed in healthy young females.

Locomotor, cardiocirculatory and metabolic adaptations to training in Andalusian and Anglo-Arabian horses.

PubMed

Muñoz, A; Santisteban, R; Rubio, M D; Agüera, E I; Escribano, B M; Castejón, F M

1999-02-01

The effects of two training programmes in 20 Andalusian and 12 Anglo-Arabian horses were evaluated by an increasing intensity work test at velocities of 4, 5, 6, 7 and 8 m sec(-1). Heart rate was monitored and blood samples were drawn at rest and after each velocity to analyse packed cell volume, haemoglobin concentration, plasma lactate and potassium levels. Furthermore, the programmes were video-taped and stride length, duration and frequency, stance (restraint and propulsion), swing phase durations and stride vertical component were measured. The training protocol of the Andalusian horses produced significant decreases in the cardiovascular, haematological and metabolic responses to exercise. Locomotory training adaptation consisted of an increased stride frequency and a reduced stride length and vertical stride component. The last variable was the limiting factor of stride length both before and after training in the Andalusian horses. A different training protocol for show-jumping competition in Anglo-Arabian horses failed to show significant differences in the studied parameters to the work test, although an increase in stride length at velocities of over 6 m sec(-1) was observed. Stride vertical component did not have an effect on the physiological response to exercise, either before or after training.

Impact of SCBA size and fatigue from different firefighting work cycles on firefighter gait.

PubMed

Kesler, Richard M; Bradley, Faith F; Deetjen, Grace S; Angelini, Michael J; Petrucci, Matthew N; Rosengren, Karl S; Horn, Gavin P; Hsiao-Wecksler, Elizabeth T

2018-04-04

Risk of slips, trips and falls in firefighters maybe influenced by the firefighter's equipment and duration of firefighting. This study examined the impact of a four self-contained breathing apparatus (SCBA) three SCBA of increasing size and a prototype design and three work cycles one bout (1B), two bouts with a five-minute break (2B) and two bouts back-to-back (BB) on gait in 30 firefighters. Five gait parameters (double support time, single support time, stride length, step width and stride velocity) were examined pre- and post-firefighting activity. The two largest SCBA resulted in longer double support times relative to the smallest SCBA. Multiple bouts of firefighting activity resulted in increased single and double support time and decreased stride length, step width and stride velocity. These results suggest that with larger SCBA or longer durations of activity, firefighters may adopt more conservative gait patterns to minimise fall risk. Practitioner Summary: The effects of four self-contained breathing apparatus (SCBA) and three work cycles on five gait parameters were examined pre- and post-firefighting activity. Both SCBA size and work cycle affected gait. The two largest SCBA resulted in longer double support times. Multiple bouts of activity resulted in more conservative gait patterns.

Validation of a commercial inertial sensor system for spatiotemporal gait measurements in children.

PubMed

Lanovaz, Joel L; Oates, Alison R; Treen, Tanner T; Unger, Janelle; Musselman, Kristin E

2017-01-01

Although inertial sensor systems are becoming a popular tool for gait analysis in both healthy and pathological adult populations, there are currently no data on the validity of these systems for use with children. The purpose of this study was to validate spatiotemporal data from a commercial inertial sensor system (MobilityLab) in typically-developing children. Data from 10 children (5 males; 3.0-8.3 years, mean=5.1) were collected simultaneously from MobilityLab and 3D motion capture during gait at self-selected and fast walking speeds. Spatiotemporal parameters were compared between the two methods using a Bland-Altman method. The results indicate that, while the temporal gait measurements were similar between the two systems, MobilityLab demonstrated a consistent bias with respect to measurement of the spatial data (stride length). This error is likely due to differences in relative leg length and gait characteristics in children compared to the MobilityLab adult reference population used to develop the stride length algorithm. A regression-based equation was developed based on the current data to correct the MobilityLab stride length output. The correction was based on leg length, stride time, and shank range-of-motion, each of which were independently associated with stride length. Once the correction was applied, all of the spatiotemporal parameters evaluated showed good agreement. The results of this study indicate that MobilityLab is a valid tool for gait analysis in typically-developing children. Further research is needed to determine the efficacy of this system for use in children suffering from pathologies that impact gait mechanics. Copyright © 2016 Elsevier B.V. All rights reserved.

Multidirectional walk test in individuals with Parkinson's disease: a validity study.

PubMed

Bryant, Mon S; Workman, Craig D; Jackson, George R

2015-03-01

Gait parameters of forward, backward, and sideways walk were studied when the participants walked overground in four directions at their self-selected speed and were compared with walking in the four directions on an instrumented GAITRite walkway. Intraclass correlation coefficients between the overground walk test measures and the instrumented walkway measures of gait speed, cadence, and stride length for the forward walk were 0.85, 0.88, and 0.87, respectively. For the backward walk, the coefficients were 0.91 for gait speed, 0.75 for cadence, and 0.93 for stride length. For the sideways walk, the coefficients were 0.92 for gait speed, 0.93 for cadence, and 0.94 for stride length. Gait parameters of forward, backward, and sideways walk obtained by the overground walk test had excellent agreement with those obtained by the instrumented walkway. The quick timed test provided quantitative data for gait evaluation and was valid for clinical use.

Effects of footwear and stride length on metatarsal strains and failure in running.

PubMed

Firminger, Colin R; Fung, Anita; Loundagin, Lindsay L; Edwards, W Brent

2017-11-01

The metatarsal bones of the foot are particularly susceptible to stress fracture owing to the high strains they experience during the stance phase of running. Shoe cushioning and stride length reduction represent two potential interventions to decrease metatarsal strain and thus stress fracture risk. Fourteen male recreational runners ran overground at a 5-km pace while motion capture and plantar pressure data were collected during four experimental conditions: traditional shoe at preferred and 90% preferred stride length, and minimalist shoe at preferred and 90% preferred stride length. Combined musculoskeletal - finite element modeling based on motion analysis and computed tomography data were used to quantify metatarsal strains and the probability of failure was determined using stress-life predictions. No significant interactions between footwear and stride length were observed. Running in minimalist shoes increased strains for all metatarsals by 28.7% (SD 6.4%; p<0.001) and probability of failure for metatarsals 2-4 by 17.3% (SD 14.3%; p≤0.005). Running at 90% preferred stride length decreased strains for metatarsal 4 by 4.2% (SD 2.0%; p≤0.007), and no differences in probability of failure were observed. Significant increases in metatarsal strains and the probability of failure were observed for recreational runners acutely transitioning to minimalist shoes. Running with a 10% reduction in stride length did not appear to be a beneficial technique for reducing the risk of metatarsal stress fracture, however the increased number of loading cycles for a given distance was not detrimental either. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dual-tasks and walking fast: relationship to extra-pyramidal signs in advanced Alzheimer disease.

PubMed

Camicioli, Richard; Bouchard, Thomas; Licis, Lisa

2006-10-25

Extra-pyramidal signs (EPS) and cadence predicted falls risk in patients with advanced Alzheimer disease (AD). Dual task performance predicts falls with variable success. Dual-task performance and walking fast were examined in advanced AD patients with EPS (EPS+, >3 modified Unified Parkinson's Disease Rating Scale [UPDRS] signs) or without EPS (EPS-, three or less UPDRS signs). Demographics, mental and functional status, behavioral impairment, EPS, and quantitative gait measures (GaitRite) were determined. The effects of an automatic dual-task (simple counting) and of walking fast on spatial and temporal gait characteristics were compared between EPS+ and EPS- subjects using a repeated measures design. Cadence decreased, while stride time, swing time and variability in swing time increased with the dual task. Results were insignificant after adjusting for secondary task performance. With walking fast, speed, cadence and stride length increased while stride time, swing time and double support time decreased. Although EPS+ subjects were slower and had decreased stride length, dual task and walking fast effects did not differ from EPS- subjects. Patient characteristics, the type of secondary task and the specific gait measures examined vary in the literature. In this moderately to severely demented population, EPS did not affect "unconscious" (dual task) or "conscious" (walking fast) gait modulation. Given their high falls risk, and retained ability to modulate walking, EPS+ AD patients may be ideal candidates for interventions aimed at preventing falls.

Gait and risk of falls associated with frontal cognitive functions at different stages of Alzheimer's disease.

PubMed

Coelho, Flávia Gomes de Melo; Stella, Florindo; de Andrade, Larissa Pires; Barbieri, Fabio Augusto; Santos-Galduróz, Ruth Ferreira; Gobbi, Sebastião; Costa, José Luiz Riani; Gobbi, Lilian Teresa Bucken

2012-09-01

The decline in frontal cognitive functions contributes to alterations of gait and increases the risk of falls in patients with dementia, a category which included Alzheimer's disease (AD). The objective of the present study was to compare the gait parameters and the risk of falls among patients at different stages of AD, and to relate these variables with cognitive functions. This is a cross-sectional study with 23 patients with mild and moderate AD. The Clinical Dementia Rating was used to classify the dementia severity. The kinematic parameters of gait (cadence, stride length, and stride speed) were analyzed under two conditions: (a) single task (free gait) and (b) dual task (walking and counting down). The risk of falls was evaluated using the Timed Up-and-Go test. The frontal cognitive functions were evaluated using the Frontal Assessment Battery (FAB), the Clock Drawing Test (CDT) and the Symbol Search Subtest. The patients who were at the moderate stage suffered reduced performance in their stride length and stride speed in the single task and had made more counting errors in the dual task and still had a higher fall risk. Both the mild and the moderate patients exhibited significant decreases in stride length, stride speed and cadence in the dual task. Was detected a significant correlation between CDT, FAB, and stride speed in the dual task condition. We also found a significant correlation between subtest Similarities, FAB and cadence in the dual task condition. The dual task produced changes in the kinematic parameters of gait for the mild and moderate AD patients and the gait alterations are related to frontal cognitive functions, particularly executive functions.

Inducing self-selected human engagement in robotic locomotion training.

PubMed

Collins, Steven H; Jackson, Rachel W

2013-06-01

Stroke leads to severe mobility impairments for millions of individuals each year. Functional outcomes can be improved through manual treadmill therapy, but high costs limit patient exposure and, thereby, outcomes. Robotic gait training could increase the viable duration and frequency of training sessions, but robotic approaches employed thus far have been less effective than manual therapy. These shortcomings may relate to subconscious energy-minimizing drives, which might cause patients to engage less actively in therapy when provided with corrective robotic assistance. We have devised a new method for gait rehabilitation that harnesses, rather than fights, least-effort tendencies. Therapeutic goals, such as increased use of the paretic limb, are made easier than the patient's nominal gait through selective assistance from a robotic platform. We performed a pilot test on a healthy subject (N = 1) in which altered self-selected stride length was induced using a tethered robotic ankle-foot orthosis. The subject first walked on a treadmill while wearing the orthosis with and without assistance at unaltered and voluntarily altered stride length. Voluntarily increasing stride length by 5% increased metabolic energy cost by 4%. Robotic assistance decreased energy cost at both unaltered and voluntarily increased stride lengths, by 6% and 8% respectively. We then performed a test in which the robotic system continually monitored stride length and provided more assistance if the subject's stride length approached a target increase. This adaptive assistance protocol caused the subject to slowly adjust their gait patterns towards the target, leading to a 4% increase in stride length. Metabolic energy consumption was simultaneously reduced by 5%. These results suggest that selective-assistance protocols based on targets relevant to rehabilitation might lead patients to self-select desirable gait patterns during robotic gait training sessions, possibly facilitating better adherence and outcomes.

[Kinetics of heifers and cows walking on an instrumented treadmill].

PubMed

Nuss, K; Waldern, N M; Weishaupt, M A; Wiestner, T

2015-01-01

Kinetic data of stride characteristics and ground reaction forces of cattle become increasingly important as automated lameness detection may be installed in dairy cow housing systems in the future. Therefore, sound heifers and cows were measured on an instrumented treadmill to collect such basic data. Nine heifers and 10 cows were trained to walk on an instrumented treadmill. Vertical ground reaction forces as well as step and stride timing and length variables were measured for all limbs simultaneously. On average, 16 stride cycles in cows and 24 strides in heifers were analysed in each case. The cows walked on the treadmill at an average speed of 1.2 ± 0.05 m/s (mean ± standard deviation), with a stride rate of 43.0 ± 1.9/min and a stride length of 1.68 ± 0.1 m. The heifers had average values of 1.3 ± 0.04 m/s, 53.7 ± 2.2/min and 1.49 ± 0.05 m, respectively. The stance duration relative to stride duration (the duty factor) was for the cows significantly longer in the forelimbs (67%) than in the hind limbs (64%). Force-time-curves of all limbs showed two peaks, one after landing (FP1) and another during push off (FP2). Vertical ground reaction force was highest for FP1 in the hind limbs, but for FP2 in the forelimbs. At all limbs, force minimum between the peaks occurred shortly before midstance. The vertical impulse carried by both forelimbs amounted to 53.7% of the total stride impulse in cows and to 55.0% in heifers. The location of the centre of body mass varied during the stride cycle but was always located more towards the front limbs. Cows and heifers showed a symmetrical walk with minimal intra-individual variations. Relative stride impulse of the front limbs was higher than that of the hind limbs. Peak vertical force in the hind limbs was highest at landing and in the forelimbs at push off. The present study offers kinetic data of sound cows and heifers which might be helpful as guidelines for automated systems for lameness detection in cattle.

Instrumented gait analysis: a measure of gait improvement by a wheeled walker in hospitalized geriatric patients.

PubMed

Schülein, Samuel; Barth, Jens; Rampp, Alexander; Rupprecht, Roland; Eskofier, Björn M; Winkler, Jürgen; Gaßmann, Karl-Günter; Klucken, Jochen

2017-02-27

In an increasing aging society, reduced mobility is one of the most important factors limiting activities of daily living and overall quality of life. The ability to walk independently contributes to the mobility, but is increasingly restricted by numerous diseases that impair gait and balance. The aim of this cross-sectional observation study was to examine whether spatio-temporal gait parameters derived from mobile instrumented gait analysis can be used to measure the gait stabilizing effects of a wheeled walker (WW) and whether these gait parameters may serve as surrogate marker in hospitalized patients with multifactorial gait and balance impairment. One hundred six patients (ages 68-95) wearing inertial sensor equipped shoes passed an instrumented walkway with and without gait support from a WW. The walkway assessed the risk of falling associated gait parameters velocity, swing time, stride length, stride time- and double support time variability. Inertial sensor-equipped shoes measured heel strike and toe off angles, and foot clearance. The use of a WW improved the risk of spatio-temporal parameters velocity, swing time, stride length and the sagittal plane associated parameters heel strike and toe off angles in all patients. First-time users (FTUs) showed similar gait parameter improvement patterns as frequent WW users (FUs). However, FUs with higher levels of gait impairment improved more in velocity, stride length and toe off angle compared to the FTUs. The impact of a WW can be quantified objectively by instrumented gait assessment. Thus, objective gait parameters may serve as surrogate markers for the use of walking aids in patients with gait and balance impairments.

Kinetic and temporospatial parameters in male and female cats walking over a pressure sensing walkway.

PubMed

Verdugo, Mirela R; Rahal, Sheila C; Agostinho, Felipe S; Govoni, Verônica M; Mamprim, Maria J; Monteiro, Frederico O B

2013-06-27

Several factors may influence kinetic data measurements, including body conformation and body mass. In addition, gender differences in gait pattern have been observed in healthy humans. Therefore, the aim of this study was to compare the kinetic and temporospatial parameters in clinically healthy male and female cats using a pressure-sensitive walkway. Eighteen crossbreed adult cats were divided into two groups: G1 had ten male cats (nine neutered) aged from 1 to 4 years and body mass 3.1-6.8 kg; G2 had eight spayed female cats, aged from 1 to 6 years and body mass 3.3-4.75 kg. The data from the first five valid trials were collected for each cat. A trial was considered valid if the cat maintained a velocity between 0.54-0.74 m/s and acceleration from -0.20 to 0.20 m/s2. The peak vertical force (PVF), vertical impulse (VI), gait cycle time, stance time, swing time, stride length, and percentage body weight distribution among the four limbs were determined. In addition, the lengths of each forelimb and each hind limb were measured using a tape with the animal standing. No significant differences were observed in each group in either the forelimbs or the hind limbs or between the left and right sides for any of the variables. For both groups, the PVF (%BW), the VI, and the percentage body weight distribution were higher at the forelimbs than the hind limbs. The stride length was larger for males; however, the other kinetic and temporospatial variables did not show any statistically significant differences between the groups. The lengths of the forelimbs and hind limbs were larger in the male cats. There was a significant moderate positive correlation between the stride length and the length of the limbs. In conclusion, the only difference observed between male and female cats was the stride length, and this was due to the greater body size of male cats. This difference did not affect other temporospatial or kinetics variables.

Manipulating the stride length/stride velocity relationship of walking using a treadmill and rhythmic auditory cueing in non-disabled older individuals. A short-term feasibility study.

PubMed

Eikema, D J A; Forrester, L W; Whitall, J

2014-09-01

One target for rehabilitating locomotor disorders in older adults is to increase mobility by improving walking velocity. Combining rhythmic auditory cueing (RAC) and treadmill training permits the study of the stride length/stride velocity ratio (SL/SV), often reduced in those with mobility deficits. We investigated the use of RAC to increase velocity by manipulating the SL/SV ratio in older adults. Nine participants (6 female; age: 61.1 ± 8.8 years) walked overground on a gait mat at preferred and fast speeds. After acclimatization to comfortable speed on a treadmill, participants adjusted their cadence to match the cue for 3 min at 115% of preferred speed by either (a) increasing stride length only or (b) increasing stride frequency only. Following training, participants walked across the gait mat at preferred velocity without, and then with, RAC. Group analysis determined no immediate overground velocity increase, but reintroducing RAC did produce an increase in velocity after both conditions. Group and single subject analysis determined that the SL/SV ratio changed in the intended direction only in the stride length condition. We conclude that RAC is a powerful organizer of gait parameters, evidenced by its induced after-effects following short duration training. Copyright © 2014 Elsevier B.V. All rights reserved.

Muscular strategy shift in human running: dependence of running speed on hip and ankle muscle performance.

PubMed

Dorn, Tim W; Schache, Anthony G; Pandy, Marcus G

2012-06-01

Humans run faster by increasing a combination of stride length and stride frequency. In slow and medium-paced running, stride length is increased by exerting larger support forces during ground contact, whereas in fast running and sprinting, stride frequency is increased by swinging the legs more rapidly through the air. Many studies have investigated the mechanics of human running, yet little is known about how the individual leg muscles accelerate the joints and centre of mass during this task. The aim of this study was to describe and explain the synergistic actions of the individual leg muscles over a wide range of running speeds, from slow running to maximal sprinting. Experimental gait data from nine subjects were combined with a detailed computer model of the musculoskeletal system to determine the forces developed by the leg muscles at different running speeds. For speeds up to 7 m s(-1), the ankle plantarflexors, soleus and gastrocnemius, contributed most significantly to vertical support forces and hence increases in stride length. At speeds greater than 7 m s(-1), these muscles shortened at relatively high velocities and had less time to generate the forces needed for support. Thus, above 7 m s(-1), the strategy used to increase running speed shifted to the goal of increasing stride frequency. The hip muscles, primarily the iliopsoas, gluteus maximus and hamstrings, achieved this goal by accelerating the hip and knee joints more vigorously during swing. These findings provide insight into the strategies used by the leg muscles to maximise running performance and have implications for the design of athletic training programs.

Influence of footwear and equipment on stride length and range of motion of ankle, knee and hip joint.

PubMed

Schulze, Christoph; Lindner, Tobias; Woitge, Sandra; Schulz, Katharina; Finze, Susanne; Mittelmeier, Wolfram; Bader, Rainer

2014-01-01

Footwear and equipment worn by military personnel is of importance for them to be able to meet the physical demands specific to their profession daily activities. The aim of the present study was to investigate by means of gait analysis how army-provided footwear and equipment influence the range of motion of hip, knee and ankle joints as well as stride length. Thirty-two soldiers were subjected to gait analysis on a treadmill by way of video recordings and goniometric measurements. The stride length increased when military shoes are worn. We found no influence on stride length in connection to increased loading. The weight of the shoes represents the decisive factor. Neither shoes nor equipment changed the range of motion of the knee joint. Weight of equipment affected range of motion of the hip joint. The range of motion of the upper and lower ankle joints was mainly influenced by the properties of the shoes. Military footwear and weight of equipment influence stride length and range of motion of joints of the lower extremities in a specific way. Shape of material is the decisive factor.

Energy absorption of impacts during running at various stride lengths.

PubMed

Derrick, T R; Hamill, J; Caldwell, G E

1998-01-01

The foot-ground impact experienced during running produces a shock wave that is transmitted through the human skeletal system. This shock wave is attenuated by deformation of the ground/shoe as well as deformation of biological tissues in the body. The goal of this study was to investigate the locus of energy absorption during the impact phase of the running cycle. Running speed (3.83 m x s[-1]) was kept constant across five stride length conditions: preferred stride length (PSL), +10% of PSL, -10% of PSL, +20% of PSL, and -20% of PSL. Transfer functions were generated from accelerometers attached to the leg and head of ten male runners. A rigid body model was used to estimate the net energy absorbed at the hip, knee, and ankle joints. There was an increasing degree of shock attenuation as stride length increased. The energy absorbed during the impact portion of the running cycle also increased with stride length. Muscles that cross the knee joint showed the greatest adjustment in response to increased shock. It was postulated that the increased perpendicular distance from the line of action of the resultant ground reaction force to the knee joint center played a role in this increased energy absorption.

Interaction effects of stride angle and strike pattern on running economy.

PubMed

Santos-Concejero, J; Tam, N; Granados, C; Irazusta, J; Bidaurrazaga-Letona, I; Zabala-Lili, J; Gil, S M

2014-12-01

This study aimed to investigate the relationship between stride angle and running economy (RE) in athletes with different foot strike patterns. 30 male runners completed 4 min running stages on a treadmill at different velocities. During the test, biomechanical variables such as stride angle, swing time, contact time, stride length and frequency were recorded using an optical measurement system. Their foot strike pattern was determined, and VO2 at velocities below the lactate threshold were measured to calculate RE. Midfoot/forefoot strikers had better RE than rearfoot strikers (201.5±5.6 ml · kg(-1) · km(-1) vs. 213.5±4.2 ml · kg(-1) · km(-1)respectively; p=0.019). Additionally, midfoot/fore-foot strikers presented higher stride angles than rearfoot strikers (p=0.043). Linear modelling analysis showed that stride angle is closely related to RE (r=0.62, p<0.001) and that the effect of stride angle on RE was different in the 2 groups. From an arbitrary value of 4°, a rearfoot strike pattern is likely to be more economical, whereas at any lower degree, the midfoot/forefoot strike pattern appears to be more desirable. A biomechanical running technique characterised by high stride angles and a midfoot/forefoot strike pattern is advantageous for a better RE. Athletes may find stride angle useful for improving RE. © Georg Thieme Verlag KG Stuttgart · New York.

Exploring the relationship between stride, stature and hand size for forensic assessment.

PubMed

Guest, Richard; Miguel-Hurtado, Oscar; Stevenage, Sarah; Black, Sue

2017-11-01

Forensic evidence often relies on a combination of accurately recorded measurements, estimated measurements from landmark data such as a subject's stature given a known measurement within an image, and inferred data. In this study a novel dataset is used to explore linkages between hand measurements, stature, leg length and stride. These three measurements replicate the type of evidence found in surveillance videos with stride being extracted from an automated gait analysis system. Through correlations and regression modelling, it is possible to generate accurate predictions of stature from hand size, leg length and stride length (and vice versa), and to predict leg and stride length from hand size with, or without, stature as an intermediary variable. The study also shows improved accuracy when a subject's sex is known a-priori. Our method and models indicate the possibility of calculating or checking relationships between a suspect's physical measurements, particularly when only one component is captured as an accurately recorded measurement. Copyright © 2017 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Effect of stride length on overarm throwing delivery: A linear momentum response.

PubMed

Ramsey, Dan K; Crotin, Ryan L; White, Scott

2014-12-01

Changing stride length during overhand throwing delivery is thought to alter total body and throwing arm linear momentums, thereby altering the proportion of throwing arm momentum relative to the total body. Using a randomized cross-over design, nineteen pitchers (15 collegiate and 4 high school) were assigned to pitch two simulated 80-pitch games at ±25% of their desired stride length. An 8-camera motion capture system (240Hz) integrated with two force plates (960Hz) and radar gun tracked each throw. Segmental linear momentums in each plane of motion were summed yielding throwing arm and total body momentums, from which compensation ratio's (relative contribution between the two) were derived. Pairwise comparisons at hallmark events and phases identified significantly different linear momentum profiles, in particular, anteriorly directed total body, throwing arm, and momentum compensation ratios (P⩽.05) as a result of manipulating stride length. Pitchers with shorter strides generated lower forward (anterior) momentum before stride foot contact, whereas greater upward and lateral momentum (toward third base) were evident during the acceleration phase. The evidence suggests insufficient total body momentum in the intended throwing direction may potentially influence performance (velocity and accuracy) and perhaps precipitate throwing arm injuries. Copyright © 2014 Elsevier B.V. All rights reserved.

Increased gait variability may not imply impaired stride-to-stride control of walking in healthy older adults: Winner: 2013 Gait and Clinical Movement Analysis Society Best Paper Award.

PubMed

Dingwell, Jonathan B; Salinas, Mandy M; Cusumano, Joseph P

2017-06-01

Older adults exhibit increased gait variability that is associated with fall history and predicts future falls. It is not known to what extent this increased variability results from increased physiological noise versus a decreased ability to regulate walking movements. To "walk", a person must move a finite distance in finite time, making stride length (L n ) and time (T n ) the fundamental stride variables to define forward walking. Multiple age-related physiological changes increase neuromotor noise, increasing gait variability. If older adults also alter how they regulate their stride variables, this could further exacerbate that variability. We previously developed a Goal Equivalent Manifold (GEM) computational framework specifically to separate these causes of variability. Here, we apply this framework to identify how both young and high-functioning healthy older adults regulate stepping from each stride to the next. Healthy older adults exhibited increased gait variability, independent of walking speed. However, despite this, these healthy older adults also concurrently exhibited no differences (all p>0.50) from young adults either in how their stride variability was distributed relative to the GEM or in how they regulated, from stride to stride, either their basic stepping variables or deviations relative to the GEM. Using a validated computational model, we found these experimental findings were consistent with increased gait variability arising solely from increased neuromotor noise, and not from changes in stride-to-stride control. Thus, age-related increased gait variability likely precedes impaired stepping control. This suggests these changes may in turn precede increased fall risk. Copyright © 2017 Elsevier B.V. All rights reserved.

Generalization of improved step length symmetry from treadmill to overground walking in persons with stroke and hemiparesis†

PubMed Central

Savin, Douglas N.; Morton, Susanne M.; Whitall, Jill

2013-01-01

Objectives Determine whether adaptation to a swing phase perturbation during gait transferred from treadmill to overground walking, the rate of overground deadaptation, and whether overground aftereffects improved step length asymmetry in persons with hemiparetic stroke and gait asymmetry. Methods Ten participants with stroke and hemiparesis and 10 controls walked overground on an instrumented gait mat, adapted gait to a swing phase perturbation on a treadmill, then walked overground on the gait mat again. Outcome measures, primary: overground step length symmetry, rates of treadmill step length symmetry adaptation and overground step length symmetry deadaptation; secondary: overground gait velocity, stride length, and stride cycle duration. Results Step length symmetry aftereffects generalized to overground walking and adapted at a similar rate on the treadmill in both groups. Aftereffects decayed at a slower rate overground in participants with stroke and temporarily improved overground step length asymmetry. Both groups’ overground gait velocity increased post adaptation due to increased stride length and decreased stride duration. Conclusions Stroke and hemiparesis do not impair generalization of step length symmetry changes from adapted treadmill to overground walking, but prolong overground aftereffects. Significance Motor adaptation during treadmill walking may be an effective treatment for improving overground gait asymmetries post-stroke. PMID:24286858

Parkinsonian gait ameliorated with a moving handrail, not with a banister.

PubMed

Rabin, Ely; Demin, Aleksandr; Pirrotta, Stefania; Chen, Jason; Patel, Hemal; Bhambri, Ankur; Noyola, Estella; Lackner, James R; DiZio, Paul; DiFrancisco-Donoghue, Joanne; Werner, William

2015-04-01

To determine whether haptic (touch and proprioception) cues from touching a moving handrail while walking can ameliorate the gait symptoms of Parkinson disease (PD), such as slowness and small stride length. Nonrandomized, controlled before-after trial. Physical therapy clinic. People with PD (n=16) and healthy age-matched control subjects (n=16) with no neurologic disorders volunteered. No participants withdrew. We compared gait using a moving handrail as a novel assistive aid (speed self-selected) versus a banister and unassisted walking. Participants with PD were tested on and off dopaminergic medication. Mean gait speed, stride length, stride duration, double-support duration, and medial-lateral excursion. With the moving handrail, participants with PD increased gait speed relative to unassisted gait by 16% (.166m/s, P=.009, d=.76; 95% confidence interval [CI], .054-.278m/s) and increased stride length by 10% (.053m, P=.022, d=.37; 95% CI, .009-.097m) without significantly changing stride or double-support duration. The banister reduced speed versus unassisted gait by 11% (-.097m/s, P=.040, d=.40; 95% CI, .002-.193m/s) and reduced stride length by 8% (.32m, P=.004, d=.26; 95% CI, .010-.054m), whereas it increased stride duration by 3% (.023s, P=.022, d=.21; 95% CI, .004-.041s) and double-support duration by 35% (.044s, P=.031, d=.58; 95% CI, .005-.083s). All medication × condition interactions were P>.05. Using haptic speed cues from the moving handrail, people with PD walked faster by spontaneously (ie, without specific instruction) increasing stride length without altering cadence; banisters slowed gait. Haptic cues from the moving handrail can be used by people with PD to engage biomechanical and neural mechanisms for interpreting tactile and proprioception changes related to gait speed to control gait better than static cues afforded by banisters. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Cockroaches traverse crevices, crawl rapidly in confined spaces, and inspire a soft, legged robot

PubMed Central

Jayaram, Kaushik; Full, Robert J.

2016-01-01

Jointed exoskeletons permit rapid appendage-driven locomotion but retain the soft-bodied, shape-changing ability to explore confined environments. We challenged cockroaches with horizontal crevices smaller than a quarter of their standing body height. Cockroaches rapidly traversed crevices in 300–800 ms by compressing their body 40–60%. High-speed videography revealed crevice negotiation to be a complex, discontinuous maneuver. After traversing horizontal crevices to enter a vertically confined space, cockroaches crawled at velocities approaching 60 cm⋅s−1, despite body compression and postural changes. Running velocity, stride length, and stride period only decreased at the smallest crevice height (4 mm), whereas slipping and the probability of zigzag paths increased. To explain confined-space running performance limits, we altered ceiling and ground friction. Increased ceiling friction decreased velocity by decreasing stride length and increasing slipping. Increased ground friction resulted in velocity and stride length attaining a maximum at intermediate friction levels. These data support a model of an unexplored mode of locomotion—“body-friction legged crawling” with body drag, friction-dominated leg thrust, but no media flow as in air, water, or sand. To define the limits of body compression in confined spaces, we conducted dynamic compressive cycle tests on living animals. Exoskeletal strength allowed cockroaches to withstand forces 300 times body weight when traversing the smallest crevices and up to nearly 900 times body weight without injury. Cockroach exoskeletons provided biological inspiration for the manufacture of an origami-style, soft, legged robot that can locomote rapidly in both open and confined spaces. PMID:26858443

Cockroaches traverse crevices, crawl rapidly in confined spaces, and inspire a soft, legged robot.

PubMed

Jayaram, Kaushik; Full, Robert J

2016-02-23

Jointed exoskeletons permit rapid appendage-driven locomotion but retain the soft-bodied, shape-changing ability to explore confined environments. We challenged cockroaches with horizontal crevices smaller than a quarter of their standing body height. Cockroaches rapidly traversed crevices in 300-800 ms by compressing their body 40-60%. High-speed videography revealed crevice negotiation to be a complex, discontinuous maneuver. After traversing horizontal crevices to enter a vertically confined space, cockroaches crawled at velocities approaching 60 cm⋅s(-1), despite body compression and postural changes. Running velocity, stride length, and stride period only decreased at the smallest crevice height (4 mm), whereas slipping and the probability of zigzag paths increased. To explain confined-space running performance limits, we altered ceiling and ground friction. Increased ceiling friction decreased velocity by decreasing stride length and increasing slipping. Increased ground friction resulted in velocity and stride length attaining a maximum at intermediate friction levels. These data support a model of an unexplored mode of locomotion--"body-friction legged crawling" with body drag, friction-dominated leg thrust, but no media flow as in air, water, or sand. To define the limits of body compression in confined spaces, we conducted dynamic compressive cycle tests on living animals. Exoskeletal strength allowed cockroaches to withstand forces 300 times body weight when traversing the smallest crevices and up to nearly 900 times body weight without injury. Cockroach exoskeletons provided biological inspiration for the manufacture of an origami-style, soft, legged robot that can locomote rapidly in both open and confined spaces.

Increased delivery stride length places greater loads on the ankle joint in elite male cricket fast bowlers.

PubMed

Spratford, Wayne; Hicks, Amy

2014-01-01

The purpose of this study was to investigate the effect stride length has on ankle biomechanics of the leading leg with reference to the potential risk of injury in cricket fast bowlers. Ankle joint kinematic and kinetic data were collected from 51 male fast bowlers during the stance phase of the final delivery stride. The bowling cohort comprised national under-19, first class and international-level athletes. Bowlers were placed into either Short, Average or Long groups based on final stride length, allowing statistical differences to be measured. A multivariate analysis of variance with a Bonferroni post-hoc correction (α = 0.05) revealed significant differences between peak plantarflexion angles (Short-Long P = 0.005, Average and Long P = 0.04) and negative joint work (Average-Long P = 0.026). This study highlighted that during fast bowling the ankle joint of the leading leg experiences high forces under wide ranges of movement. As stride length increases, greater amounts of negative work and plantarflexion are experienced. These increases place greater loads on the ankle joint and move the foot into positions that make it more susceptible to injuries such as posterior impingement syndrome.

Six-week transition to minimalist shoes improves running economy and time-trial performance.

PubMed

Fuller, Joel T; Thewlis, Dominic; Tsiros, Margarita D; Brown, Nicholas A T; Buckley, Jonathan D

2017-12-01

This study investigated if gradually introducing runners to minimalist shoes during training improved running economy and time-trial performance compared to training in conventional shoes. Changes in stride rate, stride length, footfall pattern and ankle plantar-flexor strength were also investigated. Randomised parallel intervention trial. 61 trained runners gradually increased the amount of running performed in either minimalist (n=31) or conventional (n=30) shoes during a six-week standardised training program. 5-km time-trial performance, running economy, ankle plantar-flexor strength, footfall pattern, stride rate and length were assessed in the allocated shoes at baseline and after training. Footfall pattern was determined from the time differential between rearfoot and forefoot (TD R-F ) pressure sensors. The minimalist shoe group improved time-trial performance (effect size (ES): 0.24; 95% confidence interval (CI): 0.01, 0.48; p=0.046) and running economy (ES 0.48; 95%CI: 0.22, 0.74; p<0.001) more than the conventional shoe group. There were no minimalist shoe training effects on ankle plantar-flexor concentric (ES: 0.11; 95%CI: -0.18, 0.41; p=0.45), isometric (ES: 0.23; 95%CI: -0.17, 0.64; p=0.25), or eccentric strength (ES: 0.24; 95%CI: -0.17, 0.65; p=0.24). Minimalist shoes caused large reductions in TD R-F (ES: 1.03; 95%CI: 0.65, 1.40; p<0.001) but only two runners changed to a forefoot footfall. Minimalist shoes had no effect on stride rate (ES: 0.04; 95%CI: -0.08, 0.16; p=0.53) or length (ES: 0.06; 95%CI: -0.06, 0.18; p=0.35). Gradually introducing minimalist shoes over a six-week training block is an effective method for improving running economy and performance in trained runners. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Cognitive and motor dual task gait training improve dual task gait performance after stroke - A randomized controlled pilot trial.

PubMed

Liu, Yan-Ci; Yang, Yea-Ru; Tsai, Yun-An; Wang, Ray-Yau

2017-06-22

This study investigated effects of cognitive and motor dual task gait training on dual task gait performance in stroke. Participants (n = 28) were randomly assigned to cognitive dual task gait training (CDTT), motor dual task gait training (MDTT), or conventional physical therapy (CPT) group. Participants in CDTT or MDTT group practiced the cognitive or motor tasks respectively during walking. Participants in CPT group received strengthening, balance, and gait training. The intervention was 30 min/session, 3 sessions/week for 4 weeks. Three test conditions to evaluate the training effects were single walking, walking while performing cognitive task (serial subtraction), and walking while performing motor task (tray-carrying). Parameters included gait speed, dual task cost of gait speed (DTC-speed), cadence, stride time, and stride length. After CDTT, cognitive-motor dual task gait performance (stride length and DTC-speed) was improved (p = 0.021; p = 0.015). After MDTT, motor dual task gait performance (gait speed, stride length, and DTC-speed) was improved (p = 0.008; p = 0.008; p = 0.008 respectively). It seems that CDTT improved cognitive dual task gait performance and MDTT improved motor dual task gait performance although such improvements did not reach significant group difference. Therefore, different types of dual task gait training can be adopted to enhance different dual task gait performance in stroke.

Differences in stride between healthy ostriches (Struthio camelus) and those affected by tibiotarsal rotation.

PubMed

Cooper, R G

2007-03-01

Twenty healthy ostriches (ten cocks and ten hens), and twenty birds with tibiotarsal rotation (nine cocks and 11 hens) (14 months old) were isolated, hooded and weighed. A run (50 m x 2.5 m) was divided into sections marked 5 m, 10 m, 15 m and 20 m. Time taken for each bird to pass these points was recorded and speed computed. The degree of tibiotarsal rotation in the right foot was mean +/- SEM, 156 +/- 2.69 degrees. Comparisons between left and right foot length in healthy birds showed no significant differences. Foot length was significantly lower in tibiotarsal rotation (P = 0.03). The right foot in tibiotarsal rotation was significantly shorter than the left foot. The number of strides per each 5 m division were significantly (P < 0.05) greater in tibiotarsal rotation by comparison with healthy birds. At 20 m, healthy cocks had more strides than hens. The stride length in hens was significantly (P < 0.05) greater than cocks at 5, 10 and 15 m, respectively, but lower throughout in tibiotarsal rotation (P = 0.001). The speed of hens was significantly (P < 0.05) greater than cocks. Tibiotarsal rotation resulted in significantly (P < 0.05) reduced speeds. Hens may be able to escape danger faster than cocks. The occurrence of tibiotarsal rotation necessitates consideration of genetics, management, sex, nutrition and growth rates.

The effect of rider weight and additional weight in Icelandic horses in tölt: part II. Stride parameters responses.

PubMed

Gunnarsson, V; Stefánsdóttir, G J; Jansson, A; Roepstorff, L

2017-09-01

This study investigated the effects of rider weight in the BW ratio (BWR) range common for Icelandic horses (20% to 35%), on stride parameters in tölt in Icelandic horses. The kinematics of eight experienced Icelandic school horses were measured during an incremental exercise test using a high-speed camera (300 frames/s). Each horse performed five phases (642 m each) in tölt at a BWR between rider (including saddle) and horse starting at 20% (BWR20) and increasing to 25% (BWR25), 30% (BWR30), 35% (BWR35) and finally 20% (BWR20b) was repeated. One professional rider rode all horses and weight (lead) was added to saddle and rider as needed. For each phase, eight strides at speed of 5.5 m/s were analyzed for stride duration, stride frequency, stride length, duty factor (DF), lateral advanced placement, lateral advanced liftoff, unipedal support (UPS), bipedal support (BPS) and height of front leg action. Stride length became shorter (Y=2.73-0.004x; P0.05). In conclusion, increased BWR decreased stride length and increased DF proportionally to the same extent in all limbs, whereas BPS increased at the expense of decreased UPS. These changes can be expected to decrease tölt quality when subjectively evaluated according to the breeding goals for the Icelandic horse. However, beat, symmetry and height of front leg lifting were not affected by BWR.

Residual standard deviation: Validation of a new measure of dual-task cost in below-knee prosthesis users.

PubMed

Howard, Charla L; Wallace, Chris; Abbas, James; Stokic, Dobrivoje S

2017-01-01

We developed and evaluated properties of a new measure of variability in stride length and cadence, termed residual standard deviation (RSD). To calculate RSD, stride length and cadence are regressed against velocity to derive the best fit line from which the variability (SD) of the distance between the actual and predicted data points is calculated. We examined construct, concurrent, and discriminative validity of RSD using dual-task paradigm in 14 below-knee prosthesis users and 13 age- and education-matched controls. Subjects walked first over an electronic walkway while performing separately a serial subtraction and backwards spelling task, and then at self-selected slow, normal, and fast speeds used to derive the best fit line for stride length and cadence against velocity. Construct validity was demonstrated by significantly greater increase in RSD during dual-task gait in prosthesis users than controls (group-by-condition interaction, stride length p=0.0006, cadence p=0.009). Concurrent validity was established against coefficient of variation (CV) by moderate-to-high correlations (r=0.50-0.87) between dual-task cost RSD and dual-task cost CV for both stride length and cadence in prosthesis users and controls. Discriminative validity was documented by the ability of dual-task cost calculated from RSD to effectively differentiate prosthesis users from controls (area under the receiver operating characteristic curve, stride length 0.863, p=0.001, cadence 0.808, p=0.007), which was better than the ability of dual-task cost CV (0.692, 0.648, respectively, not significant). These results validate RSD as a new measure of variability in below-knee prosthesis users. Future studies should include larger cohorts and other populations to ascertain its generalizability. Copyright © 2016 Elsevier B.V. All rights reserved.

Kinematic constraints associated with the acquisition of overarm throwing part I: step and trunk actions.

PubMed

Stodden, David F; Langendorfer, Stephen J; Fleisig, Glenn S; Andrews, James R

2006-12-01

The purposes of this study were to: (a) examine differences within specific kinematic variables and ball velocity associated with developmental component levels of step and trunk action (Roberton & Halverson, 1984), and (b) if the differences in kinematic variables were significantly associated with the differences in component levels, determine potential kinematic constraints associated with skilled throwing acquisition. Results indicated stride length (69.3 %) and time from stride foot contact to ball release (39. 7%) provided substantial contributions to ball velocity (p < .001). All trunk kinematic measures increased significantly with increasing component levels (p < .001). Results suggest that trunk linear and rotational velocities, degree of trunk tilt, time from stride foot contact to ball release, and ball velocity represented potential control parameters and, therefore, constraints on overarm throwing acquisition.

Use of harmonic ratios to examine the effect of cueing strategies on gait stability in persons with Parkinson's disease.

PubMed

Lowry, Kristin A; Carrel, Andrew J; McIlrath, Jessica M; Smiley-Oyen, Ann L

2010-04-01

To determine if gait stability, as measured by harmonic ratios (HRs) derived from trunk accelerations, is improved during 3 amplitude-based cueing strategies (visual cues, lines on the floor 20% longer than preferred step length; verbal cues, experimenter saying "big step" every third; cognitive cues, participants think "big step") in people with Parkinson's disease. Gait analysis with a triaxial accelerometer. University research laboratory. A volunteer sample of persons with Parkinson's disease (N=7) (Hoehn and Yahr stages 2-3). Not applicable Gait stability was quantified by anterior-posterior (AP), vertical, and mediolateral (ML) HRs; higher ratios indicated improved gait stability. Spatiotemporal parameters assessed were walking speed, stride length, cadence, and the coefficient of variation for stride time. Of the amplitude-based cues, verbal and cognitive resulted in the largest improvements in the AP HR (P=.018) with a trend in the vertical HR as well as the largest improvements in both stride length and velocity. None of the cues positively affected stability in the ML direction. Descriptively, all participants increased speed and stride length, but only those in Hoehn and Yahr stage 2 (not Hoehn and Yahr stage 3) showed improvements in HRs. Cueing for "big steps" is effective for improving gait stability in the AP direction with modest improvements in the vertical direction, but it is not effective in the ML direction. These data support the use of trunk acceleration measures in assessing the efficacy of common therapeutic interventions. Copyright 2010 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

How humans use visual optic flow to regulate stepping during walking.

PubMed

Salinas, Mandy M; Wilken, Jason M; Dingwell, Jonathan B

2017-09-01

Humans use visual optic flow to regulate average walking speed. Among many possible strategies available, healthy humans walking on motorized treadmills allow fluctuations in stride length (L n ) and stride time (T n ) to persist across multiple consecutive strides, but rapidly correct deviations in stride speed (S n =L n /T n ) at each successive stride, n. Several experiments verified this stepping strategy when participants walked with no optic flow. This study determined how removing or systematically altering optic flow influenced peoples' stride-to-stride stepping control strategies. Participants walked on a treadmill with a virtual reality (VR) scene projected onto a 3m tall, 180° semi-cylindrical screen in front of the treadmill. Five conditions were tested: blank screen ("BLANK"), static scene ("STATIC"), or moving scene with optic flow speed slower than ("SLOW"), matched to ("MATCH"), or faster than ("FAST") walking speed. Participants took shorter and faster strides and demonstrated increased stepping variability during the BLANK condition compared to the other conditions. Thus, when visual information was removed, individuals appeared to walk more cautiously. Optic flow influenced both how quickly humans corrected stride speed deviations and how successful they were at enacting this strategy to try to maintain approximately constant speed at each stride. These results were consistent with Weber's law: healthy adults more-rapidly corrected stride speed deviations in a no optic flow condition (the lower intensity stimuli) compared to contexts with non-zero optic flow. These results demonstrate how the temporal characteristics of optic flow influence ability to correct speed fluctuations during walking. Copyright © 2017 Elsevier B.V. All rights reserved.

A single hydrotherapy session increases range of motion and stride length in Labrador retrievers diagnosed with elbow dysplasia.

PubMed

Preston, T; Wills, A P

2018-04-01

Canine elbow dysplasia is a debilitating condition of unknown aetiology and is a common cause of forelimb lameness in dogs. Canine hydrotherapy is a therapeutic approach rapidly increasing in popularity for the treatment of a range of musculoskeletal pathologies. In this study, kinematic analysis was used to assess the effect of a customised hydrotherapy session on the range of motion, stride length and stride frequency of healthy Labrador retrievers (n=6) and Labrador retrievers diagnosed with bilateral elbow dysplasia (n=6). Reflective kinematic markers were attached to bony anatomical landmarks and dogs were recorded walking at their preferred speed on a treadmill before and 10min after a single hydrotherapy session. Range of motion, stride length and stride frequency were calculated for both forelimbs. Data were analysed via a robust mixed ANOVA to assess the effect of hydrotherapy on the kinematic parameters of both groups. Range of motion was greater in the healthy dogs at baseline (P<0.05). Hydrotherapy increased the range of motion of the forelimbs of both groups (P<0.05); dogs with elbow dysplasia demonstrated a greater improvement in range of motion than healthy dogs (P<0.05). Hydrotherapy stride length (P<0.01) of all dogs, but differences were not seen between the two groups. Stride frequency increased after hydrotherapy only in the left limb (P<0.05) in all dogs. These results support the potential of canine hydrotherapy as a therapeutic tool for the rehabilitation and treatment of Labradors with elbow dysplasia. Furthermore, results indicate that hydrotherapy might improve the gait and movement of healthy dogs. However, whether these results are transient or sustained remains undetermined. Copyright © 2018 Elsevier Ltd. All rights reserved.

Strategies for obstacle avoidance during walking in the cat.

PubMed

Chu, Kevin M I; Seto, Sandy H; Beloozerova, Irina N; Marlinski, Vladimir

2017-08-01

Avoiding obstacles is essential for successful navigation through complex environments. This study aimed to clarify what strategies are used by a typical quadruped, the cat, to avoid obstacles during walking. Four cats walked along a corridor 2.5 m long and 25 or 15 cm wide. Obstacles, small round objects 2.5 cm in diameter and 1 cm in height, were placed on the floor in various locations. Movements of the paw were recorded with a motion capture and analysis system (Visualeyez, PTI). During walking in the wide corridor, cats' preferred strategy for avoiding a single obstacle was circumvention, during which the stride direction changed while stride duration and swing-to-stride duration ratio were preserved. Another strategy, stepping over the obstacle, was used during walking in the narrow corridor, when lateral deviations of walking trajectory were restricted. Stepping over the obstacle involved changes in two consecutive strides. The stride preceding the obstacle was shortened, and swing-to-stride ratio was reduced. The obstacle was negotiated in the next stride of increased height and normal duration and swing-to-stride ratio. During walking on a surface with multiple obstacles, both strategies were used. To avoid contact with the obstacle, cats placed the paw away from the object at a distance roughly equal to the diameter of the paw. During obstacle avoidance cats prefer to alter muscle activities without altering the locomotor rhythm. We hypothesize that a choice of the strategy for obstacle avoidance is determined by minimizing the complexity of neuro-motor processes required to achieve the behavioral goal. NEW & NOTEWORTHY In a study of feline locomotor behavior we found that the preferred strategy to avoid a small obstacle is circumvention. During circumvention, stride direction changes but length and temporal structure are preserved. Another strategy, stepping over the obstacle, is used in narrow walkways. During overstepping, two strides adjust. A stride preceding the obstacle decreases in length and duration. The following stride negotiating the obstacle increases in height while retaining normal temporal structure and nearly normal length. Copyright © 2017 the American Physiological Society.

Exploring the feasibility and acceptability of sensor monitoring of gait and falls in the homes of persons with multiple sclerosis.

PubMed

Newland, Pamela; Wagner, Joanne M; Salter, Amber; Thomas, Florian P; Skubic, Marjorie; Rantz, Marilyn

2016-09-01

Gait parameters variability and falls are problems for persons with MS and have not been adequately captured in the home. Our goal was to explore the feasibility and acceptability of monitoring of gait and falls in the homes of persons with MS over a period of 30 days. To test the feasibility of measuring gait and falls for 30days in the home of persons with MS, spatiotemporal gait parameters stride length, stride time, and gait speed were compared. A 3D infrared depth imaging system has been developed to objectively measure gait and falls in the home environment. Participants also completed a 16-foot GaitRite electronic pathway walk to validate spatiotemporal parameters of gait (gait speed (cm/s), stride length (cm), and gait cycle time(s)) during the timed 25 foot walking test (T25FWT). We also documented barriers to feasibility of installing the in-home sensors for these participants. The results of the study suggest that the Kinect sensor may be used as an alternative device to measure gait for persons with MS, depending on the desired accuracy level. Ultimately, using in-home sensors to analyze gait parameters in real time is feasible and could lead to better analysis of gait in persons with MS. Copyright © 2016 Elsevier B.V. All rights reserved.

Effects of gyrokinesis exercise on the gait pattern of female patients with chronic low back pain

PubMed Central

Seo, Kook-Eun; Park, Tae-Jin

2016-01-01

[Purpose] The purpose of the present study was to use kinematic variables to identify the effects of 8/weeks’ performance of a gyrokinesis exercise on the gait pattern of females with chronic low back pain. [Subjects] The subjects of the present study were females in their late 20s to mid 30s who were chronic back pain patients. [Methods] A 3-D motion analysis system was used to measure the changes in their gait patterns between pre and post-gyrokintic exercise. The SPSS 21.0 statistics program was used to perform the paired t-test, to compare the gait patterns of pre-post-gyrokinesis exercise. [Results] In the gait analysis, pre-post-gyrokinesis exercise gait patterns showed statistically significant differences in right and left step length, stride length, right-left step widths, and stride speed. [Conclusion] Gait pattern analysis revealed increases in step length, stride length, and stride speed along with a decrease in step width after 8 weeks of gyrokinesis exercise, demonstrating it improved gait pattern. PMID:27065537

Effects of a Flexibility and Relaxation Programme, Walking, and Nordic Walking on Parkinson's Disease

PubMed Central

Reuter, I.; Mehnert, S.; Leone, P.; Kaps, M.; Oechsner, M.; Engelhardt, M.

2011-01-01

Symptoms of Parkinson's disease (PD) progress despite optimized medical treatment. The present study investigated the effects of a flexibility and relaxation programme, walking, and Nordic walking (NW) on walking speed, stride length, stride length variability, Parkinson-specific disability (UPDRS), and health-related quality of life (PDQ 39). 90 PD patients were randomly allocated to the 3 treatment groups. Patients participated in a 6-month study with 3 exercise sessions per week, each lasting 70 min. Assessment after completion of the training showed that pain was reduced in all groups, and balance and health-related quality of life were improved. Furthermore, walking, and Nordic walking improved stride length, gait variability, maximal walking speed, exercise capacity at submaximal level, and PD disease-specific disability on the UPDRS in addition. Nordic walking was superior to the flexibility and relaxation programme and walking in improving postural stability, stride length, gait pattern and gait variability. No significant injuries occurred during the training. All patients of the Nordic walking group continued Nordic walking after completing the study. PMID:21603199

Energy Expenditure of Trotting Gait Under Different Gait Parameters

NASA Astrophysics Data System (ADS)

Chen, Xian-Bao; Gao, Feng

2017-07-01

Robots driven by batteries are clean, quiet, and can work indoors or in space. However, the battery endurance is a great problem. A new gait parameter design energy saving strategy to extend the working hours of the quadruped robot is proposed. A dynamic model of the robot is established to estimate and analyze the energy expenditures during trotting. Given a trotting speed, optimal stride frequency and stride length can minimize the energy expenditure. However, the relationship between the speed and the optimal gait parameters is nonlinear, which is difficult for practical application. Therefore, a simplified gait parameter design method for energy saving is proposed. A critical trotting speed of the quadruped robot is found and can be used to decide the gait parameters. When the robot is travelling lower than this speed, it is better to keep a constant stride length and change the cycle period. When the robot is travelling higher than this speed, it is better to keep a constant cycle period and change the stride length. Simulations and experiments on the quadruped robot show that by using the proposed gait parameter design approach, the energy expenditure can be reduced by about 54% compared with the 100 mm stride length under 500 mm/s speed. In general, an energy expenditure model based on the gait parameter of the quadruped robot is built and the trotting gait parameters design approach for energy saving is proposed.

Gait cycle analysis: parameters sensitive for functional evaluation of peripheral nerve recovery in rat hind limbs.

PubMed

Rui, Jing; Runge, M Brett; Spinner, Robert J; Yaszemski, Michael J; Windebank, Anthony J; Wang, Huan

2014-10-01

Video-assisted gait kinetics analysis has been a sensitive method to assess rat sciatic nerve function after injury and repair. However, in conduit repair of sciatic nerve defects, previously reported kinematic measurements failed to be a sensitive indicator because of the inferior recovery and inevitable joint contracture. This study aimed to explore the role of physiotherapy in mitigating joint contracture and to seek motion analysis indices that can sensitively reflect motor function. Data were collected from 26 rats that underwent sciatic nerve transection and conduit repair. Regular postoperative physiotherapy was applied. Parameters regarding step length, phase duration, and ankle angle were acquired and analyzed from video recording of gait kinetics preoperatively and at regular postoperative intervals. Stride length ratio (step length of uninjured foot/step length of injured foot), percent swing of the normal paw (percentage of the total stride duration when the uninjured paw is in the air), propulsion angle (toe-off angle subtracted by midstance angle), and clearance angle (ankle angle change from toe off to midswing) decreased postoperatively comparing with baseline values. The gradual recovery of these measurements had a strong correlation with the post-nerve repair time course. Ankle joint contracture persisted despite rigorous physiotherapy. Parameters acquired from a 2-dimensional motion analysis system, that is, stride length ratio, percent swing of the normal paw, propulsion angle, and clearance angle, could sensitively reflect nerve function impairment and recovery in the rat sciatic nerve conduit repair model despite the existence of joint contractures.

A Pilot Study of Gait Function in Farmworkers in Eastern North Carolina.

PubMed

Nguyen, Ha T; Kritchevsky, Stephen B; Foxworth, Judy L; Quandt, Sara A; Summers, Phillip; Walker, Francis O; Arcury, Thomas A

2015-01-01

Farmworkers endure many job-related hazards, including fall-related work injuries. Gait analysis may be useful in identifying potential fallers. The goal of this pilot study was to explore differences in gait between farmworkers and non-farmworkers. The sample included 16 farmworkers and 24 non-farmworkers. Gait variables were collected using the portable GAITRite system, a 16-foot computerized walkway. Generalized linear regression models were used to examine group differences. All models were adjusted for two established confounders, age and body mass index. There were no significant differences in stride length, step length, double support time, and base of support; but farmworkers had greater irregularity of stride length (P = .01) and step length (P = .08). Farmworkers performed significantly worse on gait velocity (P = .003) and cadence (P < .001) relative to non-farmworkers. We found differences in gait function between farmworkers and non-farmworkers. These findings suggest that measuring gait with a portable walkway system is feasible and informative in farmworkers and may possibly be of use in assessing fall risk.

A new look at the Dynamic Similarity Hypothesis: the importance of swing phase.

PubMed

Raichlen, David A; Pontzer, Herman; Shapiro, Liza J

2013-01-01

The Dynamic Similarity Hypothesis (DSH) suggests that when animals of different size walk at similar Froude numbers (equal ratios of inertial and gravitational forces) they will use similar size-corrected gaits. This application of similarity theory to animal biomechanics has contributed to fundamental insights in the mechanics and evolution of a diverse set of locomotor systems. However, despite its popularity, many mammals fail to walk with dynamically similar stride lengths, a key element of gait that determines spontaneous speed and energy costs. Here, we show that the applicability of the DSH is dependent on the inertial forces examined. In general, the inertial forces are thought to be the centripetal force of the inverted pendulum model of stance phase, determined by the length of the limb. If instead we model inertial forces as the centripetal force of the limb acting as a suspended pendulum during swing phase (determined by limb center of mass position), the DSH for stride length variation is fully supported. Thus, the DSH shows that inter-specific differences in spatial kinematics are tied to the evolution of limb mass distribution patterns. Selection may act on morphology to produce a given stride length, or alternatively, stride length may be a "spandrel" of selection acting on limb mass distribution.

The behavioral assessment and alleviation of pain associated with castration in beef calves treated with flunixin meglumine and caudal lidocaine epidural anesthesia with epinephrine

PubMed Central

Currah, Jan M.; Hendrick, Steven H.; Stookey, Joseph M.

2009-01-01

The objectives of this study were 1) to determine the effects of flunixin megulmine in combination with caudal epidural anesthesia as a postoperative analgesic in beef calves following surgical castration, and 2) to consider stride length and pedometry as potential behavioral assessment tools for detecting postcastration pain. Surgical castration was performed in 101 beef calves randomly assigned to 3 treatment subgroups: 1) castration without anesthesia (SURG); 2) castration following lidocaine with epinephrine caudal epidural anesthesia (SURG + EPI); 3) castration following lidocaine with epinephrine caudal epidural anesthesia and flunixin meglumine (SURG + EPI + F). Several outcomes, including pedometer counts, changes in stride length, subjective visual assessment of pain, instantaneous scan sampling of the calves’ postoperative activities, and the amount of movement and vocalization during the castration procedure, were measured to identify and quantify pain. The results indicated that stride length and the number of steps taken by calves after castration appear to be good measures of pain. Significant differences found between treatment groups for stride length and visual assessments suggest that flunixin meglumine can be considered to provide visible pain relief up to 8 hours postcastration. PMID:19436444

The behavioral assessment and alleviation of pain associated with castration in beef calves treated with flunixin meglumine and caudal lidocaine epidural anesthesia with epinephrine.

PubMed

Currah, Jan M; Hendrick, Steven H; Stookey, Joseph M

2009-04-01

The objectives of this study were 1) to determine the effects of flunixin megulmine in combination with caudal epidural anesthesia as a postoperative analgesic in beef calves following surgical castration, and 2) to consider stride length and pedometry as potential behavioral assessment tools for detecting postcastration pain. Surgical castration was performed in 101 beef calves randomly assigned to 3 treatment subgroups: 1) castration without anesthesia (SURG); 2) castration following lidocaine with epinephrine caudal epidural anesthesia (SURG + EPI); 3) castration following lidocaine with epinephrine caudal epidural anesthesia and flunixin meglumine (SURG + EPI + F). Several outcomes, including pedometer counts, changes in stride length, subjective visual assessment of pain, instantaneous scan sampling of the calves' postoperative activities, and the amount of movement and vocalization during the castration procedure, were measured to identify and quantify pain. The results indicated that stride length and the number of steps taken by calves after castration appear to be good measures of pain. Significant differences found between treatment groups for stride length and visual assessments suggest that flunixin meglumine can be considered to provide visible pain relief up to 8 hours postcastration.

Gait variability in community dwelling adults with Alzheimer disease.

PubMed

Webster, Kate E; Merory, John R; Wittwer, Joanne E

2006-01-01

Studies have shown that measures of gait variability are associated with falling in older adults. However, few studies have measured gait variability in people with Alzheimer disease, despite the high incidence of falls in Alzheimer disease. The purpose of this study was to compare gait variability of community-dwelling older adults with Alzheimer disease and control subjects at various walking speeds. Ten subjects with mild-moderate Alzheimer disease and ten matched control subjects underwent gait analysis using an electronic walkway. Participants were required to walk at self-selected slow, preferred, and fast speeds. Stride length and step width variability were determined using the coefficient of variation. Results showed that stride length variability was significantly greater in the Alzheimer disease group compared with the control group at all speeds. In both groups, increases in walking speed were significantly correlated with decreases in stride length variability. Step width variability was significantly reduced in the Alzheimer disease group compared with the control group at slow speed only. In conclusion, there is an increase in stride length variability in Alzheimer disease at all walking speeds that may contribute to the increased incidence of falls in Alzheimer disease.

Acute differences in foot strike and spatiotemporal variables for shod, barefoot or minimalist male runners.

PubMed

McCallion, Ciara; Donne, Bernard; Fleming, Neil; Blanksby, Brian

2014-05-01

This study compared stride length, stride frequency, contact time, flight time and foot-strike patterns (FSP) when running barefoot, and in minimalist and conventional running shoes. Habitually shod male athletes (n = 14; age 25 ± 6 yr; competitive running experience 8 ± 3 yr) completed a randomised order of 6 by 4-min treadmill runs at velocities (V1 and V2) equivalent to 70 and 85% of best 5-km race time, in the three conditions. Synchronous recording of 3-D joint kinematics and ground reaction force data examined spatiotemporal variables and FSP. Most participants adopted a mid-foot strike pattern, regardless of condition. Heel-toe latency was less at V2 than V1 (-6 ± 20 vs. -1 ± 13 ms, p < 0.05), which indicated a velocity related shift towards a more FFS pattern. Stride duration and flight time, when shod and in minimalist footwear, were greater than barefoot (713 ± 48 and 701 ± 49 vs. 679 ± 56 ms, p < 0.001; and 502 ± 45 and 503 ± 41 vs. 488 ±4 9 ms, p < 0.05, respectively). Contact time was significantly longer when running shod than barefoot or in minimalist footwear (211±30 vs. 191 ± 29 ms and 198 ± 33 ms, p < 0.001). When running barefoot, stride frequency was significantly higher (p < 0.001) than in conventional and minimalist footwear (89 ± 7 vs. 85 ± 6 and 86 ± 6 strides·min(-1)). In conclusion, differences in spatiotemporal variables occurred within a single running session, irrespective of barefoot running experience, and, without a detectable change in FSP. Key pointsDifferences in spatiotemporal variables occurred within a single running session, without a change in foot strike pattern.Stride duration and flight time were greater when shod and in minimalist footwear than when barefoot.Stride frequency when barefoot was higher than when shod or in minimalist footwear.Contact time when shod was longer than when barefoot or in minimalist footwear.Spatiotemporal variables when running in minimalist footwear more closely resemble shod than barefoot running.

Acute Differences in Foot Strike and Spatiotemporal Variables for Shod, Barefoot or Minimalist Male Runners

PubMed Central

McCallion, Ciara; Donne, Bernard; Fleming, Neil; Blanksby, Brian

2014-01-01

This study compared stride length, stride frequency, contact time, flight time and foot-strike patterns (FSP) when running barefoot, and in minimalist and conventional running shoes. Habitually shod male athletes (n = 14; age 25 ± 6 yr; competitive running experience 8 ± 3 yr) completed a randomised order of 6 by 4-min treadmill runs at velocities (V1 and V2) equivalent to 70 and 85% of best 5-km race time, in the three conditions. Synchronous recording of 3-D joint kinematics and ground reaction force data examined spatiotemporal variables and FSP. Most participants adopted a mid-foot strike pattern, regardless of condition. Heel-toe latency was less at V2 than V1 (-6 ± 20 vs. -1 ± 13 ms, p < 0.05), which indicated a velocity related shift towards a more FFS pattern. Stride duration and flight time, when shod and in minimalist footwear, were greater than barefoot (713 ± 48 and 701 ± 49 vs. 679 ± 56 ms, p < 0.001; and 502 ± 45 and 503 ± 41 vs. 488 ±4 9 ms, p < 0.05, respectively). Contact time was significantly longer when running shod than barefoot or in minimalist footwear (211±30 vs. 191 ± 29 ms and 198 ± 33 ms, p < 0.001). When running barefoot, stride frequency was significantly higher (p < 0.001) than in conventional and minimalist footwear (89 ± 7 vs. 85 ± 6 and 86 ± 6 strides·min-1). In conclusion, differences in spatiotemporal variables occurred within a single running session, irrespective of barefoot running experience, and, without a detectable change in FSP. Key points Differences in spatiotemporal variables occurred within a single running session, without a change in foot strike pattern. Stride duration and flight time were greater when shod and in minimalist footwear than when barefoot. Stride frequency when barefoot was higher than when shod or in minimalist footwear. Contact time when shod was longer than when barefoot or in minimalist footwear. Spatiotemporal variables when running in minimalist footwear more closely resemble shod than barefoot running. PMID:24790480

The Effect of a Six-Month Dancing Program on Motor-Cognitive Dual-Task Performance in Older Adults.

PubMed

Hamacher, Dennis; Hamacher, Daniel; Rehfeld, Kathrin; Hökelmann, Anita; Schega, Lutz

2015-10-01

Dancing is a complex sensorimotor activity involving physical and mental elements which have positive effects on cognitive functions and motor control. The present randomized controlled trial aims to analyze the effects of a dancing program on the performance on a motor-cognitive dual task. Data of 35 older adults, who were assigned to a dancing group or a health-related exercise group, are presented in the study. In pretest and posttest, we assessed cognitive performance and variability of minimum foot clearance, stride time, and stride length while walking. Regarding the cognitive performance and the stride-to-stride variability of minimum foot clearance, interaction effects have been found, indicating that dancing lowers gait variability to a higher extent than conventional health-related exercise. The data show that dancing improves minimum foot clearance variability and cognitive performance in a dual-task situation. Multi-task exercises (like dancing) might be a powerful tool to improve motor-cognitive dual-task performance.

Gait characteristics, balance performance and falls in ambulant adults with cerebral palsy: An observational study.

PubMed

Morgan, P; Murphy, A; Opheim, A; McGinley, J

2016-07-01

The relationship between spatiotemporal gait parameters, balance performance and falls history was investigated in ambulant adults with cerebral palsy (CP). Participants completed a single assessment of gait using an instrumented walkway at preferred and fast speeds, balance testing (Balance Evaluation Systems Test; BESTest), and reported falls history. Seventeen ambulatory adults with CP, mean age 37 years, participated. Gait speed was typically slow at both preferred and fast speeds (mean 0.97 and 1.21m/s, respectively), with short stride length and high cadence relative to speed. There was a significant, large positive relationship between preferred gait speed and BESTest total score (ρ=0.573; p<0.05) and fast gait speed and BESTest total score (ρ=0.647, p<0.01). The stride lengths of fallers at both preferred and fast speeds differed significantly from non-fallers (p=0.032 and p=0.025, respectively), with those with a prior history of falls taking shorter strides. Faster gait speed was associated with better performance on tests of anticipatory and postural response components of the BESTest, suggesting potential therapeutic training targets to address either gait speed or balance performance. Future exploration of the implications of slow walking speed and reduced stride length on falls and community engagement, and the potential prognostic value of stride length on identifying falls risk is recommended. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

Effects of a capacitive-resistive electric transfer therapy on physiological and biomechanical parameters in recreational runners: A randomized controlled crossover trial.

PubMed

Duñabeitia, Iratxe; Arrieta, Haritz; Torres-Unda, Jon; Gil, Javier; Santos-Concejero, Jordan; Gil, Susana M; Irazusta, Jon; Bidaurrazaga-Letona, Iraia

2018-05-26

This study compared the effects of a capacitive-resistive electric transfer therapy (Tecar) and passive rest on physiological and biomechanical parameters in recreational runners when performed shortly after an exhausting training session. Randomized controlled crossover trial. University biomechanical research laboratory. Fourteen trained male runners MAIN OUTCOME MEASURES: Physiological (running economy, oxygen uptake, respiratory exchange ratio, ventilation, heart rate, blood lactate concentration) and biomechanical (step length; stride angle, height, frequency, and contact time; swing time; contact phase; support phase; push-off phase) parameters were measured during two incremental treadmill running tests performed two days apart after an exhaustive training session. When running at 14 km/h and 16 km/h, the Tecar treatment group presented greater increases in stride length (p < 0.001), angle (p < 0.05) and height (p < 0.001) between the first and second tests than the control group and, accordingly, greater decreases in stride frequency (p < 0.05). Physiological parameters were similar between groups. The present study suggests that a Tecar therapy intervention enhances biomechanical parameters in recreational runners after an exhaustive training session more than passive rest, generating a more efficient running pattern without affecting selected physiological parameters. Copyright © 2018 Elsevier Ltd. All rights reserved.

Gait Implications of Visual Field Damage from Glaucoma.

PubMed

Mihailovic, Aleksandra; Swenor, Bonnielin K; Friedman, David S; West, Sheila K; Gitlin, Laura N; Ramulu, Pradeep Y

2017-06-01

To evaluate fall-relevant gait features in older glaucoma patients. The GAITRite Electronic Walkway was used to define fall-related gait parameters in 239 patients with suspected or manifest glaucoma under normal usual-pace walking conditions and while carrying a cup or tray. Multiple linear regression models assessed the association between gait parameters and integrated visual field (IVF) sensitivity after controlling for age, race, sex, medications, and comorbid illness. Under normal walking conditions, worse IVF sensitivity was associated with a wider base of support (β = 0.60 cm/5 dB IVF sensitivity decrement, 95% confidence interval [CI] = 0.12-1.09, P = 0.016). Worse IVF sensitivity was not associated with slower gait speed, shorter step or stride length, or greater left-right drift under normal walking conditions ( P > 0.05 for all), but was during cup and/or tray carrying conditions ( P < 0.05 for all). Worse IVF sensitivity was positively associated with greater stride-to-stride variability in step length, stride length, and stride velocity ( P < 0.005 for all). Inferior and superior IVF sensitivity demonstrated associations with each of the above gait parameters as well, though these associations were consistently similar to, or weaker than, the associations noted for overall IVF sensitivity. Glaucoma severity was associated with several gait parameters predictive of higher fall risk in prior studies, particularly measures of stride-to-stride variability. Gait may be useful in identifying glaucoma patients at higher risk of falls, and in designing and testing interventions to prevent falls in this high-risk group. These findings could serve to inform the development of the interventions for falls prevention in glaucoma patients.

Strategy quantification using body worn inertial sensors in a reactive agility task.

PubMed

Eke, Chika U; Cain, Stephen M; Stirling, Leia A

2017-11-07

Agility performance is often evaluated using time-based metrics, which provide little information about which factors aid or limit success. The objective of this study was to better understand agility strategy by identifying biomechanical metrics that were sensitive to performance speed, which were calculated with data from an array of body-worn inertial sensors. Five metrics were defined (normalized number of foot contacts, stride length variance, arm swing variance, mean normalized stride frequency, and number of body rotations) that corresponded to agility terms defined by experts working in athletic, clinical, and military environments. Eighteen participants donned 13 sensors to complete a reactive agility task, which involved navigating a set of cones in response to a vocal cue. Participants were grouped into fast, medium, and slow performance based on their completion time. Participants in the fast group had the smallest number of foot contacts (normalizing by height), highest stride length variance (normalizing by height), highest forearm angular velocity variance, and highest stride frequency (normalizing by height). The number of body rotations was not sensitive to speed and may have been determined by hand and foot dominance while completing the agility task. The results of this study have the potential to inform the development of a composite agility score constructed from the list of significant metrics. By quantifying the agility terms previously defined by expert evaluators through an agility score, this study can assist in strategy development for training and rehabilitation across athletic, clinical, and military domains. Copyright © 2017 Elsevier Ltd. All rights reserved.

Investigation of dairy cattle ease of movement on new methyl methacrylate resin aggregate floorings.

PubMed

Franco-Gendron, N; Bergeron, R; Curilla, W; Conte, S; DeVries, T; Vasseur, E

2016-10-01

Freestall dairy farms commonly present issues with cattle slips and falls caused by smooth flooring and manure slurry. This study examined the effect of 4 new methyl methacrylate (MMA) resin aggregate flooring types (1-4) compared with rubber (positive) and concrete (negative control) on dairy cow (n=18) ease of movement when walking on straight and right-angled corridors. Our hypothesis was that cow ease of movement when walking on the MMA surfaces would be better than when walking on traction milled concrete, and at least as good as when walking on rubber. Cattle ease of movement was measured using kinematics, accelerometers, and visual observation of gait and associated behaviors. Stride length, swing time, stance time, and hoof height were obtained from kinematic evaluation. Acceleration and asymmetry of variance were measured with accelerometers. Locomotion score and behaviors associated with lameness, such as arch back, head bob, tracking up, step asymmetry, and reluctance to bear weight were visually observed. Stride length, swing time, stance time, and the number of steps taken were the only variables affected by flooring type. Differences between flooring types for these variables were tested using a generalized linear mixed model with cow as a random effect, week as a random block factor, and flooring type as a fixed effect. Multiple comparisons with a Scheffé adjustment were done to analyze differences among flooring types. Stride length was 0.14 m longer (better) on rubber when compared with concrete, and 0.11 and 0.17 m shorter on MMA 1 and 2 compared with rubber. On MMA 3 and 4, stride length did not differ from either rubber or concrete. Swing time was 0.04 s shorter (worse) on MMA 1 than on rubber, but did not differ from any other flooring. Stance time was 0.18 s longer (worse) on MMA 2 when compared with rubber, but it did not differ from any other treatment. The number of steps was higher on MMA 4 compared with rubber (4.57 vs. 3.95 steps), but did not differ from any other treatment. Of all the MMA floors tested, MMA 3 was the only one that was consistently as good as rubber (positive control). All 4 MMA floors never differed from concrete (negative control) in any of the ease of movement variables measured. These results suggest that MMA 3 may improve cow ease of movement, compared with the other MMA floors, but more research is required to confirm these findings. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Disturbances of automatic gait control mechanisms in higher level gait disorder.

PubMed

Danoudis, Mary; Ganesvaran, Ganga; Iansek, Robert

2016-07-01

The underlying mechanisms responsible for the gait changes in frontal gait disorder (FGD), a form of higher level gait disorders, are poorly understood. We investigated the relationship between stride length and cadence (SLCrel) in people with FGD (n=15) in comparison to healthy older adults (n=21) to improve our understanding of the changes to gait in FGD. Gait data was captured using an electronic walkway system as participants walked at five self-selected speed conditions: preferred, very slow, slow, fast and very fast. Linear regression was used to determine the strength of the relationship (R(2)), slope and intercept. In the FGD group 9 participants had a strong SLCrel (linear group) (R(2)>0.8) and 6 a weak relationship (R(2)<0.8) (nonlinear group). The linear FGD group did not differ to healthy control for slope (p>0.05) but did have a lower intercept (p<0.001). The linear FGD group modulated gait speed by adjusting stride length and cadence similar to controls whereas the nonlinear FGD participants adjusted stride length but not cadence similar to controls. The non-linear FGD group had greater disturbance to their gait, poorer postural control and greater fear of falling compared to the linear FGD group. Investigation of the SLCrel resulted in new insights into the underlying mechanisms responsible for the gait changes found in FGD. The findings suggest stride length regulation was disrupted in milder FGD but as the disorder worsened, cadence control also became disordered resulting in a break down in the relationship between stride length and cadence. Copyright © 2016 Elsevier B.V. All rights reserved.

The Ergogenic Effect of Elastic Therapeutic Tape on Stride and Step Length in Fatigued Runners

PubMed Central

Ward, John; Sorrels, Kenneth; Coats, Jesse; Pourmoghaddam, Amir; Moskop, JoAnn; Ueckert, Kate; Glass, Amanda

2014-01-01

Objective The purpose of this study was to determine if elastic therapeutic tape placed on anterior lower limbs would affect stride and step length in fatigued runners’ gait. Methods Forty-two healthy participants were equally divided into a kinesiology tape group (Rocktape) and a no-tape control group. Participants in both groups underwent a baseline running gait test at 6 mph without tape. After this, participants engaged in an exhaustive lower body fatigue protocol until they reached maximal volitional exhaustion. Participants were then randomized to 1 of 2 interventions: (1) Experimental group, which had kinesiology tape placed under tension on the anterior aspect of their lower limbs bilaterally from the upper thigh to just below the patella, or (2) Control group, which did not receive taping. All participants then engaged in a similar 6-mph running gait postanalysis. Participant’s gait was analyzed for 90 seconds during each test iteration. Researchers used a 2-way repeated-measures analysis of variance considering fatigue (prefatigue, postfatigue) and group (tape, no-tape) as subject factors. Results After the fatigue protocol, the no-tape group demonstrated a significant decrease in step length of 14.2 mm (P = .041) and stride length of 29.4 mm (P = .043). The kinesiology tape group did not demonstrate a significant decline in these gait parameters. Conclusions In this preliminary study, placing elastic therapeutic tape over the anterior lower limbs demonstrated short-term preservation of runner step length and stride length in a fatigued state. PMID:25435835

Effects of Nordic walking and walking on spatiotemporal gait parameters and ground reaction force.

PubMed

Park, Seung Kyu; Yang, Dae Jung; Kang, Yang Hun; Kim, Je Ho; Uhm, Yo Han; Lee, Yong Seon

2015-09-01

[Purpose] The purpose of this study was to investigate the effects of Nordic walking and walking on spatiotemporal gait parameters and ground reaction force. [Subjects] The subjects of this study were 30 young adult males, who were divided into a Nordic walking group of 15 subjects and a walking group of 15 subjects. [Methods] To analyze the spatiotemporal parameters and ground reaction force during walking in the two groups, the six-camera Vicon MX motion analysis system was used. The subjects were asked to walk 12 meters using the more comfortable walking method for them between Nordic walking and walking. After they walked 12 meters more than 10 times, their most natural walking patterns were chosen three times and analyzed. To determine the pole for Nordic walking, each subject's height was multiplied by 0.68. We then measured the spatiotemporal gait parameters and ground reaction force. [Results] Compared with the walking group, the Nordic walking group showed an increase in cadence, stride length, and step length, and a decrease in stride time, step time, and vertical ground reaction force. [Conclusion] The results of this study indicate that Nordic walking increases the stride and can be considered as helping patients with diseases affecting their gait. This demonstrates that Nordic walking is more effective in improving functional capabilities by promoting effective energy use and reducing the lower limb load, because the weight of the upper and lower limbs is dispersed during Nordic walking.

Effect on Oxygen Cost of Transport from 8-Weeks of Progressive Training with Barefoot Running.

PubMed

Tam, N; Tucker, R; Astephen Wilson, J L; Santos-Concejero, J

2015-11-01

Popular interest in barefoot running has emerged as a result of its alleged performance and injury prevention benefits. Oxygen cost of transport (COT) improvements from barefoot running, however, remains equivocal. The aim of this study was to determine the influence of an 8-week progressive barefoot training program on COT and associated spatiotemporal variables. 15 male runners participated in this study. Variables such as oxygen uptake, biomechanical and spatiotemporal characteristics of gait, including ground contact (GC) and swing time; stride length and frequency and ankle plantar-dorsiflexion were measured pre- and post-intervention. The COT did not differ between barefoot and shod running either pre- or post-training. Improved barefoot COT (p<0.05) but not shod was found between pre- and post-training. Biomechanical differences between barefoot and shod conditions persisted over the training period. A decrease in barefoot COT was associated with a decrease in GC time (p=0.003, r=0.688) and a small increase in stride frequency (p=0.030; r=0.569). Ground contact time and stride frequency, previously associated with COT, only partly contribute (32% - Stride frequency and 47% - GC time) to a decrease in COT after barefoot training. Thus other physiological and biomechanical variables must influence the improvement in COT after a barefoot training intervention. © Georg Thieme Verlag KG Stuttgart · New York.

The Effects of Augmented Reality-based Otago Exercise on Balance, Gait, and Falls Efficacy of Elderly Women.

PubMed

Yoo, Ha-Na; Chung, Eunjung; Lee, Byoung-Hee

2013-07-01

[Purpose] The purpose of this study was to determine the effects of augmented reality-based Otago exercise on balance, gait, and falls efficacy of elderly women. [Subjects] The subjects were 21 elderly women, who were randomly divided into two groups: an augmented reality-based Otago exercise group of 10 subjects and an Otago exercise group of 11 subjects. [Methods] All subjects were evaluated for balance (Berg Balance Scale, BBS), gait parameters (velocity, cadence, step length, and stride length), and falls efficacy. Within 12 weeks, Otago exercise for muscle strengthening and balance training was conducted three times, for a period of 60 minutes each, and subjects in the experimental group performed augmented reality-based Otago exercise. [Results] Following intervention, the augmented reality-based Otago exercise group showed significant increases in BBS, velocity, cadence, step length (right side), stride length (right side and left side) and falls efficacy. [Conclusion] The results of this study suggest the feasibility and suitability of this augmented reality-based Otago exercise for elderly women.

Quantitative Gait Markers and Incident Fall Risk in Older Adults

PubMed Central

Holtzer, Roee; Lipton, Richard B.; Wang, Cuiling

2009-01-01

Background Identifying quantitative gait markers of falls in older adults may improve diagnostic assessments and suggest novel intervention targets. Methods We studied 597 adults aged 70 and older (mean age 80.5 years, 62% women) enrolled in an aging study who received quantitative gait assessments at baseline. Association of speed and six other gait markers (cadence, stride length, swing, double support, stride length variability, and swing time variability) with incident fall rate was studied using generalized estimation equation procedures adjusted for age, sex, education, falls, chronic illnesses, medications, cognition, disability as well as traditional clinical tests of gait and balance. Results Over a mean follow-up period of 20 months, 226 (38%) of the 597 participants fell. Mean fall rate was 0.44 per person-year. Slower gait speed (risk ratio [RR] per 10 cm/s decrease 1.069, 95% confidence interval [CI] 1.001–1.142) was associated with higher risk of falls in the fully adjusted models. Among six other markers, worse performance on swing (RR 1.406, 95% CI 1.027–1.926), double-support phase (RR 1.165, 95% CI 1.026–1.321), swing time variability (RR 1.007, 95% CI 1.004–1.010), and stride length variability (RR 1.076, 95% CI 1.030–1.111) predicted fall risk. The associations remained significant even after accounting for cognitive impairment and disability. Conclusions Quantitative gait markers are independent predictors of falls in older adults. Gait speed and other markers, especially variability, should be further studied to improve current fall risk assessments and to develop new interventions. PMID:19349593

Textured insoles reduce vertical loading rate and increase subjective plantar sensation in overground running.

PubMed

Wilkinson, Michael; Ewen, Alistair; Caplan, Nicholas; O'leary, David; Smith, Neil; Stoneham, Richard; Saxby, Lee

2018-05-01

The effect of textured insoles on kinetics and kinematics of overground running was assessed. 16 male injury-free-recreational runners attended a single visit (age 23 ± 5 yrs; stature 1.78 ± 0.06 m; mass 72.6 ± 9.2 kg). Overground 15-m runs were completed in flat, canvas plimsolls both with and without textured insoles at self-selected velocity on an indoor track in an order that was balanced among participants. Average vertical loading rate and peak vertical force (F peak ) were captured by force platforms. Video footage was digitised for sagittal plane hip, knee and ankle angles at foot strike and mid stance. Velocity, stride rate and length and contact and flight time were determined. Subjectively rated plantar sensation was recorded by visual scale. 95% confidence intervals estimated mean differences. Smallest worthwhile change in loading rate was defined as standardised reduction of 0.54 from a previous comparison of injured versus non-injured runners. Loading rate decreased (-25 to -9.3 BW s -1 ; 60% likely beneficial reduction) and plantar sensation was increased (46-58 mm) with the insole. F peak (-0.1 to 0.14 BW) and velocity (-0.02 to 0.06 m s -1 ) were similar. Stride length, flight and contact time were lower (-0.13 to -0.01 m; -0.02 to-0.01 s; -0.016 to -0.006 s) and stride rate was higher (0.01-0.07 steps s -1 ) with insoles. Textured insoles elicited an acute, meaningful decrease in vertical loading rate in short distance, overground running and were associated with subjectively increased plantar sensation. Reduced vertical loading rate could be explained by altered stride characteristics.

Kinetic and temporospatial gait parameters in a heterogeneous group of dogs.

PubMed

Kano, Washington T; Rahal, Sheila C; Agostinho, Felipe S; Mesquita, Luciane R; Santos, Rogerio R; Monteiro, Frederico O B; Castilho, Maira S; Melchert, Alessandra

2016-01-04

A prime concern of the gait analysis in a heterogeneous group of dogs is the potential influence of factors such as individual body size, body mass, type of gait, and velocity. Thus, this study aimed to evaluate in a heterogeneous group of dogs a possible correlation of the stride frequency with kinetic and temporospatial variables, as well as the percentage of body weight distribution (%BWD), and compare symmetry index (SI) between trotting and walking dogs. Twenty-nine clinically healthy dogs moving in a controlled velocity were used. The dogs were organized into two groups based on duty factor. Group 1 comprised 15 walking dogs, aged from 9 months to 8 years and weighing about 22.3 kg. Group 2 had 14 trotting dogs, aged from 1 to 6 years and weighing about 6.5 kg. The kinetic data and temporospatial parameters were obtained using a pressure-sensing walkway. The velocity was 0.9-1.1 m/s. The peak vertical force (PVF), vertical impulse (VI), gait cycle time, stance time, swing time, stride length, and percentages of body weight distribution among the four limbs were determined. For each variable, the SIs were calculated. Pearson's coefficient was used to evaluate correlation between stride frequency and other variables, initially in each group and after including all animals. Except for the %BWD (approximately 60% for the forelimbs and 40% for the hind limbs), all other parameters differed between groups. Considering each Group individually a strong correlation was observed for most of the temporospatial parameters, but no significant correlation occurred between stride frequency and PVF, and stride frequency and %BWD. However, including all dogs a strong correlation was observed in all temporospatial parameters, and moderate correlation between stride frequency and VI, and weak correlation between stride frequency and PVF. There was no correlation between stride frequency and %BWD. Groups 1 and 2 did not differ statistically in SIs. In a heterogeneous group of dogs conducted at a controlled velocity, the %BWD and most of SIs presented low variability. However, %BWD seems to be the most accurate, since factors such as the magnitude of the variables may influence the SIs inducing wrong interpretation. Based on results obtained from correlations, the standardization of stride frequency could be an alternative to minimize the variability of temporospatial parameters.

The role of intrinsic muscle mechanics in the neuromuscular control of stable running in the guinea fowl

PubMed Central

Daley, Monica A; Voloshina, Alexandra; Biewener, Andrew A

2009-01-01

Here we investigate the interplay between intrinsic mechanical and neural factors in muscle contractile performance during running, which has been less studied than during walking. We report in vivo recordings of the gastrocnemius muscle of the guinea fowl (Numida meleagris), during the response and recovery from an unexpected drop in terrain. Previous studies on leg and joint mechanics following this perturbation suggested that distal leg extensor muscles play a key role in stabilisation. Here, we test this through direct recordings of gastrocnemius fascicle length (using sonomicrometry), muscle–tendon force (using buckle transducers), and activity (using indwelling EMG). Muscle recordings were analysed from the stride just before to the second stride following the perturbation. The gastrocnemius exhibits altered force and work output in the perturbed and first recovery strides. Muscle work correlates strongly with leg posture at the time of ground contact. When the leg is more extended in the drop step, net gastrocnemius work decreases (−5.2 J kg−1versus control), and when the leg is more flexed in the step back up, it increases (+9.8 J kg−1versus control). The muscle's work output is inherently stabilising because it pushes the body back toward its pre-perturbation (level running) speed and leg posture. Gastrocnemius length and force return to level running means by the second stride following the perturbation. EMG intensity differs significantly from level running only in the first recovery stride following the perturbation, not within the perturbed stride. The findings suggest that intrinsic mechanical factors contribute substantially to the initial changes in muscle force and work. The statistical results suggest that a history-dependent effect, shortening deactivation, may be an important factor in the intrinsic mechanical changes, in addition to instantaneous force–velocity and force–length effects. This finding suggests the potential need to incorporate history-dependent muscle properties into neuromechanical simulations of running, particularly if high muscle strains are involved and stability characteristics are important. Future work should test whether a Hill or modified Hill type model provides adequate prediction in such conditions. Interpreted in light of previous studies on walking, the findings support the concept of speed-dependent roles of reflex feedback. PMID:19359369

Good agreement between smart device and inertial sensor-based gait parameters during a 6-min walk.

PubMed

Proessl, F; Swanson, C W; Rudroff, T; Fling, B W; Tracy, B L

2018-05-28

Traditional laboratory-based kinetic and kinematic gait analyses are expensive, time-intensive, and impractical for clinical settings. Inertial sensors have gained popularity in gait analysis research and more recently smart devices have been employed to provide quantification of gait. However, no study to date has investigated the agreement between smart device and inertial sensor-based gait parameters during prolonged walking. Compare spatiotemporal gait metrics measured with a smart device versus previously validated inertial sensors. Twenty neurologically healthy young adults (7 women; age: 25.0 ± 3.7 years; BMI: 23.4 ± 2.9 kg/m 2 ) performed a 6-min walk test (6MWT) wearing inertial sensors and smart devices to record stride duration, stride length, cadence, and gait speed. Pearson correlations were used to assess associations between spatiotemporal measures from the two devices and agreement between the two methods was assessed with Bland-Altman plots and limits of agreement. All spatiotemporal gait metrics (stride duration, cadence, stride length and gait speed) showed strong (r>0.9) associations and good agreement between the two devices. Smart devices are capable of accurately reflecting many of the spatiotemporal gait metrics of inertial sensors. As the smart devices also accurately reflected individual leg output, future studies may apply this analytical strategy to clinical populations, to identify hallmarks of disability status and disease progression in a more ecologically valid environment. Copyright © 2018. Published by Elsevier B.V.

Development of independent locomotion in children with a severe visual impairment.

PubMed

Hallemans, Ann; Ortibus, Els; Truijen, Steven; Meire, Francoise

2011-01-01

Locomotion of children and adults with a visual impairment (ages 1-44, n = 28) was compared to that of age-related individuals with normal vision (n = 60). Participants walked barefoot at preferred speed while their gait was recorded by a Vicon(®) system. Walking speed, heading angle, step frequency, stride length, step width, stance phase duration and double support time were determined. Differences between groups, relationships with age and possible interaction effects were investigated. With increasing age overall improvements in gait parameters are observed. Differences between groups were a slower walking speed, a shorter stride length, a prolonged duration of stance and of double support in the individuals with a visual impairment. These may be considered either as adaptations to balance problems or as strategies to allow to foot to probe the ground. Copyright © 2011 Elsevier Ltd. All rights reserved.

Method and System for Determining Relative Displacement and Heading for Navigation

NASA Technical Reports Server (NTRS)

Sheikh, Suneel Ismail (Inventor); Pines, Darryll J. (Inventor); Conroy, Joseph Kim (Inventor); Spiridonov, Timofey N. (Inventor)

2015-01-01

A system and method for determining a location of a mobile object is provided. The system determines the location of the mobile object by determining distances between a plurality of sensors provided on a first and second movable parts of the mobile object. A stride length, heading, and separation distance between the first and second movable parts are computed based on the determined distances and the location of the mobile object is determined based on the computed stride length, heading, and separation distance.

Fear of falling and gait parameters in older adults with and without fall history.

PubMed

Makino, Keitaro; Makizako, Hyuma; Doi, Takehiko; Tsutsumimoto, Kota; Hotta, Ryo; Nakakubo, Sho; Suzuki, Takao; Shimada, Hiroyuki

2017-12-01

Fear of falling (FOF) is associated with spatial and temporal gait parameters in older adults. FOF is prevalent among older adults, both those with and without fall history. It is still unclear whether the relationships between FOF and gait parameters are affected by fall history. The aim of the present study was to compare gait parameters by the presence of FOF and fall history. A total of 3575 older adults (mean age 71.7 years, 49.7% female) met the inclusion criteria for the present study. We assessed the presence of fall history and FOF by face-to-face interview, and gait parameters (gait speed, stride length, step rate, double support time and variation of stride length) at a comfortable speed using a computerized electronic walkway. Prevalences of fall history and FOF were as follows: non-fallers without FOF 52.6% (n = 1881); fallers without FOF 6.3% (n = 227); non-fallers with FOF 34.4% (n = 1229); and fallers with FOF 6.7% (n = 238). Analysis of covariance showed significant differences among the four groups in all gait variables even after adjusting for age, sex and number of medications used. It should be noted that non-fallers with FOF showed significantly slower gait speed, shorter stride length and longer double support time than did non-fallers without FOF (P < 0.001). The present results suggest that spatial and temporal gait parameters are influenced by FOF, even in the absence of fall history. The assessment of FOF might be helpful for better understanding of age-related changes in gait control. Geriatr Gerontol Int 2017; 17: 2455-2459. © 2017 Japan Geriatrics Society.

The influence of lower limb amputation level on the approach in the amputee long jump.

PubMed

Nolan, Lee; Lees, Adrian

2007-02-15

In this study, we investigated the adjustments to posture, kinematic and temporal characteristics of performance made by lower limb amputees during the last few strides in preparation for long jump take-off. Six male unilateral trans-femoral and seven male unilateral trans-tibial amputees competing in a World Championships final were filmed in the sagittal plane using a 100-Hz digital video camera positioned so that the last three strides to take-off were visible. After digitizing using a nine-segment model, a range of kinematic variables were computed to define technique characteristics. Both the trans-femoral and trans-tibial athletes appeared to achieve their reduction in centre of mass during the flight phase between strides, and did so mainly by extending the flight time by increasing stride length, achieved by a greater flexion of the hip joint of the touch-down leg. The trans-tibial athletes appeared to adopt a technique similar to that previously reported for able-bodied athletes. They lowered their centre of mass most on their second last stride (-1.6% of body height compared with -1.4% on the last stride) and used a flexed knee at take-off on the last stride, but they were less able to control their downward velocity at touch-down (-0.4 m x s(-1)). Both this and their restricted approach speed (8.9 m x s(-1) at touch-down), rather than technique limitations, influenced their jump performance. The trans-femoral athletes lowered their centre of mass most on the last stride (-2.3% of body height compared with -1.6% on the second last stride) and, as they were unable to flex their prosthetic knee sufficiently, achieved this by abducting their prosthetic leg during the support phase, which led to a large downward velocity at touch-down (-0.6 m x s(-1)). This, combined with their slower approach velocity (7.1 m x s(-1) at touch-down), restricted their performance.

Gait dynamics in Pisa syndrome and Camptocormia: The role of stride length and hip kinematics.

PubMed

Tramonti, C; Di Martino, S; Unti, E; Frosini, D; Bonuccelli, U; Rossi, B; Ceravolo, R; Chisari, C

2017-09-01

This is an observational cross-sectional study evaluating gait dynamics in patients with Parkinson's Disease (PD) and severe postural deformities, PD without axial deviations and healthy subjects. Ten PS individuals with Pisa syndrome (PS) and nine subjects with Camptocormia (CC) performed 3-D Gait Analysis and were evaluated with walking and balance scales. Correlations with clinical and functional scales were investigated. Spatio-temporal and kinematic data were compared to ten PD subjects without postural deformities (PP) and ten healthy matched individuals (CG). Data obtained showed decreased walking velocity, stride and step length in PP, PS and CC groups compared to controls. The correlation analysis showed that stride and step length were associated with reduced functional abilities and disease severity in PS and CC groups. Kinematic data revealed marked reduction in range of movements (ROMs) at all lower-extremity joints in PS group. While, in CC group the main differences were pronounced in hip and knee joints. PS and CC groups presented a more pronounced reduction in hip articular excursion compared to PP subjects, revealing an increased hip flexion pattern during gait cycle. Moreover, the increased hip and knee flexion pattern adversely affected functional performance during walking tests. Results obtained provide evidence that step length, along with stride length, can be proposed as simple and clear indicators of disease severity and reduced functional abilities. The reduction of ROMs at hip joint represented an important mechanism contributing to decreased walking velocity, balance impairment and reduced gait performance in PD patients with postural deformities. Copyright © 2017 Elsevier B.V. All rights reserved.

[Subjective Gait Stability in the Elderly].

PubMed

Hirsch, Theresa; Lampe, Jasmin; Michalk, Katrin; Röder, Lotte; Munsch, Karoline; Marquardt, Jonas

2017-07-10

It can be assumed that the feeling of gait stability or gait instability in the elderly may be independent of a possible fear of falling or a history of falling when walking. Up to now, there has been a lack of spatiotemporal gait parameters for older people who subjectively feel secure when walking. The aim of the study is to analyse the distribution of various gait parameters for older people who subjectively feel secure when walking. In a cross-sectional study, the gait parameters stride time, step time, stride length, step length, double support, single support, and walking speed were measured using a Vicon three-dimensional motion capture system (Plug-In Gait Lower-Body Marker Set) in 31 healthy people aged 65 years and older (mean age 72 ± 3.54 years) who subjectively feel secure when walking. There was a homogeneous distribution in the gait parameters examined, with no abnormalities. The mean values have a low variance with narrow confidence intervals. This study provides evidence that people who subjectively feel secure when walking demonstrate similarly objective gait parameters..

Selective Breeding and Short-Term Access to a Running Wheel Alter Stride Characteristics in House Mice.

PubMed

Claghorn, Gerald C; Thompson, Zoe; Kay, Jarren C; Ordonez, Genesis; Hampton, Thomas G; Garland, Theodore

Postural and kinematic aspects of running may have evolved to support high runner (HR) mice to run approximately threefold farther than control mice. Mice from four replicate HR lines selectively bred for high levels of voluntary wheel running show many differences in locomotor behavior and morphology as compared with four nonselected control (C) lines. We hypothesized that HR mice would show stride alterations that have coadapted with locomotor behavior, morphology, and physiology. More specifically, we predicted that HR mice would have stride characteristics that differed from those of C mice in ways that parallel some of the adaptations seen in highly cursorial animals. For example, we predicted that limbs of HR mice would swing closer to the parasagittal plane, resulting in a two-dimensional measurement of narrowed stance width. We also expected that some differences between HR and C mice might be amplified by 6 d of wheel access, as is used to select breeders each generation. We used the DigiGait Imaging System (Mouse Specifics) to capture high-speed videos in ventral view as mice ran on a motorized treadmill across a range of speeds and then to automatically calculate several aspects of strides. Young adults of both sexes were tested both before and after 6 d of wheel access. Stride length, stride frequency, stance width, stance time, brake time, propel time, swing time, duty factor, and paw contact area were analyzed using a nested analysis of covariance, with body mass as a covariate. As expected, body mass and treadmill speed affected nearly every analyzed metric. Six days of wheel access also affected nearly every measure, indicating pervasive training effects, in both HR and C mice. As predicted, stance width was significantly narrower in HR than C mice. Paw contact area and duty factor were significantly greater in minimuscle individuals (subset of HR mice with 50%-reduced hind limb muscle mass) than in normal-muscled HR or C mice. We conclude that stride characteristics of house mice are adaptable in response to both selective breeding and changes in daily locomotor behavior (activity levels) that occur during as few as 6 d. These results have important implications for understanding the evolution and coadaptation of locomotor behavior and performance.

The Relationship Between Diabetes Mellitus, Geriatric Syndromes, Physical Function, and Gait: A Review of the Literature.

PubMed

Moreira, Bruno de Souza; Sampaio, Rosana Ferreira; Furtado, Sheyla Rossana Cavalcanti; Dias, Rosângela Corrêa; Kirkwood, Renata Noce

2016-01-01

Diabetes mellitus is a common and growing problem worldwide, especially in the elderly population imposing a huge economic burden for individuals and healthcare services. The purpose of this narrative review was to summarize the current state of knowledge about the relationship between diabetes and important geriatric syndromes, physical function measures, and gait variables. Studies pertaining to the topics were identified through on-line search of databases. Seniors with diabetes are more likely to experience falls, depression, and frailty. Furthermore, in older patients, diabetes has been associated with disability, including basic and instrumental activities of daily living, and with poorer performance on objective measures of physical function, such as sit-to-stand test, handgrip strength, Timed Up and Go (TUG) test, and Short Physical Performance Battery (SPPB). Diabetic seniors also have an altered gait pattern characterized by lower velocity and stride length, and higher step width, stance time, double support time, and stride length variability compared to non-diabetic seniors. Little is known about fear of falling in older adults with diabetes. The relationship between these outcomes and diabetes in older people is still outstanding and merits further investigation.

Spatiotemporal characteristics of motor actions by blind long jump athletes.

PubMed

Torralba, Miguel Angel; Padullés, José María; Losada, Jose Luis; López, Jose Luis

2017-01-01

Blind people depend on spatial and temporal representations to perform activities of daily living and compete in sport. The aim of this study is to determine the spatiotemporal characteristics of long jumps performed by blind athletes and compare findings with those reported for sighted athletes. We analysed a sample of 12 male athletes competing in the F11 Long Jump Finals at the Paralympic Games in London 2012. Performances were recorded using four high-speed cameras, and speeds were measured using a radar speed gun. The images were processed using validated image analysis software. The long jump run-up is shorter in blind athletes than in sighted athletes. We observed statistically significant differences for body centre of mass velocity and an increase in speed over the last three strides prior to take-off, contrasting with reports for sighted athletes and athletes with less severe visual impairment, who maintain or reduce their speed during the last stride. Stride length for the last three strides was the only spatial characteristic that was not significantly associated with effective jump distance. Blind long jumpers extend rather than shorten their last stride. Contact time with the take-off board is longer than that reported for sighted athletes. The actions of blind long jumpers, unlike those without disabilities, do not vary their leg actions during the final runway approach for optimal placement on the take-off board.

30 min of treadmill walking at self-selected speed does not increase gait variability in independent elderly.

PubMed

Da Rocha, Emmanuel S; Kunzler, Marcos R; Bobbert, Maarten F; Duysens, Jacques; Carpes, Felipe P

2018-06-01

Walking is one of the preferred exercises among elderly, but could a prolonged walking increase gait variability, a risk factor for a fall in the elderly? Here we determine whether 30 min of treadmill walking increases coefficient of variation of gait in elderly. Because gait responses to exercise depend on fitness level, we included 15 sedentary and 15 active elderly. Sedentary participants preferred a lower gait speed and made smaller steps than the actives. Step length coefficient of variation decreased ~16.9% by the end of the exercise in both the groups. Stride length coefficient of variation decreased ~9% after 10 minutes of walking, and sedentary elderly showed a slightly larger step width coefficient of variation (~2%) at 10 min than active elderly. Active elderly showed higher walk ratio (step length/cadence) than sedentary in all times of walking, but the times did not differ in both the groups. In conclusion, treadmill gait kinematics differ between sedentary and active elderly, but changes over time are similar in sedentary and active elderly. As a practical implication, 30 min of walking might be a good strategy of exercise for elderly, independently of the fitness level, because it did not increase variability in step and stride kinematics, which is considered a risk of fall in this population.

Estimation of spatial-temporal gait parameters using a low-cost ultrasonic motion analysis system.

PubMed

Qi, Yongbin; Soh, Cheong Boon; Gunawan, Erry; Low, Kay-Soon; Thomas, Rijil

2014-08-20

In this paper, a low-cost motion analysis system using a wireless ultrasonic sensor network is proposed and investigated. A methodology has been developed to extract spatial-temporal gait parameters including stride length, stride duration, stride velocity, stride cadence, and stride symmetry from 3D foot displacements estimated by the combination of spherical positioning technique and unscented Kalman filter. The performance of this system is validated against a camera-based system in the laboratory with 10 healthy volunteers. Numerical results show the feasibility of the proposed system with average error of 2.7% for all the estimated gait parameters. The influence of walking speed on the measurement accuracy of proposed system is also evaluated. Statistical analysis demonstrates its capability of being used as a gait assessment tool for some medical applications.

Habituation of 10-year-old hockey players to treadmill skating.

PubMed

Lockwood, Kelly L; Frost, Gail

2007-05-01

This study assessed changes in selected physiological and kinematic variables over 6 weeks of treadmill skating in an effort to understand the process of habituation to this novel training modality. Seven male, Atom-A hockey players who were injury-free and had no previous treadmill skating experience participated in the study. Players performed four 1-min skating bouts at progressively increasing speeds, each week, for 6 weeks. One speed (10.5 km/h) was repeated weekly to allow for assessment of the habituation process. Our criteria for habituation were: a decrease in stride rate, heart rate and rating of perceived exertion, and an increase in stride length, trunk angle and vertical movement of the centre of mass, leading to a plateau, over the course of the 6-week study. Significant decreases were seen in stride rate, heart rate and ratings of perceived exertion, and significant increases were found in stride length. Some of these changes were evident after only one week of training and all were present by week 4. After 6 weeks (24 min) of exposure to treadmill skating, all participants displayed a visibly more efficient skating style.

Kinematic scaling of locomotion by hydrostatic animals: ontogeny of peristaltic crawling by the earthworm lumbricus terrestris

PubMed

Quillin

1999-03-01

This study examined the relationship between ontogenetic increase in body size and the kinematics of peristaltic locomotion by the earthworm Lumbricus terrestris, a soft-bodied organism supported by a hydrostatic skeleton. Whereas the motions of most vertebrates and arthropods are based primarily on the changes in the joint angles between rigid body segments, the motions of soft-bodied organisms with hydrostatic skeletons are based primarily on the changes in dimensions of the deformable body segments themselves. The overall kinematics of peristaltic crawling and the dynamic shape changes of individual earthworm segments were measured for individuals ranging in body mass (mb) by almost three orders of magnitude (0.012-8.5 g). Preferred crawling speed varied both within and among individuals: earthworms crawled faster primarily by taking longer strides, but also by taking more strides per unit time and by decreasing duty factor. On average, larger worms crawled at a greater absolute speed than smaller worms (U p2finity mb0.33) and did so by taking slightly longer strides (l p2finity mb0.41, where l is stride length) than expected by geometric similarity, using slightly lower stride frequencies (f p2finity mb-0.07) and the same duty factor (df p2finity mb-0.03). Circumferential and longitudinal body wall strains were generally independent of body mass, while strain rates changed little as a function of body mass. Given the extent of kinematic variation within and among earthworms, the crawling of earthworms of different sizes can be considered to show kinematic similarity when the kinematic variables are normalized by body length. Since the motions of peristaltic organisms are based primarily on changes in the dimensions of the deformable body wall, the scaling of the material properties of the body wall is probably an especially important determinant of the scaling of the kinematics of locomotion.

Pendular motion in the brachiation of captive Lagothrix and Ateles.

PubMed

Turnquist, J E; Schmitt, D; Rose, M D; Cant, J G

1999-01-01

Pendular motion during brachiation of captive Lagothrix lagothricha lugens and Ateles fusciceps robustus was analyzed to demonstrate similarities, and differences, between these two closely related large bodied atelines. This is the first captive study of the kinematics of brachiation in Lagothrix. Videorecordings of one adult male of each species were made in a specially designed cage constructed at the DuMond Conservancy/Monkey Jungle, Miami, FL. Java software (Jandel Scientific Inc., San Rafael, CA) was used for frame-by-frame kinematic analysis of individual strides/steps. Results demonstrate that the sequence of hand and tail contacts differ significantly between the two species with Lagothrix using a new tail hold with every hand hold, while Ateles generally utilizes a new tail hold with only every other hand hold. Stride length and stride frequency, even after adjusting for limb length, also differ significantly between the two species. Lagothrix brachiation utilizes short, choppy strides with quick hand holds, while Ateles uses long, fluid strides with longer hand holds. During brachiation not only is Lagothrix's body significantly less horizontal than that of Ateles but also, within Ateles, there are significant differences between steps depending on tail use. Because of the unique nature of tail use in Ateles, many aspects of body positioning in Lagothrix more closely resemble Ateles steps without a simultaneous tail hold rather than those with one. Overall pendulum length in Lagothrix is shorter than in Ateles. Tail use in Ateles has a significant effect on maximum pendulum length during a step. Although neither species achieves the extreme pendulum effect and long period of free-flight of hylobatids in fast ricochetal brachiation, in captivity both consistently demonstrate effective brachiation with brief periods of free-flight and pendular motion. Morphological similarities between ateline brachiators and hylobatids are fewer and less pronounced in Lagothrix than in Ateles. This study demonstrates that Lagothrix brachiation is also less hylobatid-like than that of Ateles.

Objective assessment of gait in xylazine-induced ataxic horses.

PubMed

Nout-Lomas, Y S; Page, K M; Kang, H G; Aanstoos, M E; Greene, H M

2017-05-01

There is poor agreement between observers of equine neurological gait abnormalities using the modified Mayhew grading scale. To stimulate a dose-dependent ataxia in horses through xylazine administration and identify quantifiable relevant gait parameters. Balanced, randomised, 2-way crossover design. Eight horses were assessed before and after administration of xylazine (low dose and high dose). Gait analyses performed before and after xylazine administration included: 1) kinematic data collected on an equine high-speed treadmill (flat and 10% decline) and from accelerometers placed on head and sacrum; and 2) kinetic data collected on a force plate. All horses developed dose-dependent ataxia. Horses developed a dose-dependent increased stride time, stride length, and time of contact (P<0.0001), and a decreased stride frequency (P<0.0002) after administration of xylazine. Although pelvic acceleration increased in the mediolateral direction (P<0.05) in horses walked on the treadmill, this movement decreased when walking over ground after administration of xylazine (P<0.05). Furthermore, centre of pressure and path length indices changed significantly in horses following administration of xylazine (P<0.05). This study examined one breed of horse (Arabian), all of similar height and weight. Accelerometers were attached to skin, not bone; no correction was made for artefacts from skin displacement. The sedative drug effect is of certain duration, limiting the data collection period. Administration of xylazine induced a dose-dependent ataxia in horses and resulted in significant changes of gait parameters, pelvic accelerations, and stabilographic variables, some of which changed in a dose-dependent fashion. Some of the altered gait parameters in this model were probably a result of overall slowing down of the stride cycle secondary to the sedative effect. Continued efforts to discover and evaluate quantifiable gait parameters that are susceptible to change following development of clinical neurological disease in horses is warranted. © 2016 EVJ Ltd.

Theoretical considerations on maximum running speeds for large and small animals.

PubMed

Fuentes, Mauricio A

2016-02-07

Mechanical equations for fast running speeds are presented and analyzed. One of the equations and its associated model predict that animals tend to experience larger mechanical stresses in their limbs (muscles, tendons and bones) as a result of larger stride lengths, suggesting a structural restriction entailing the existence of an absolute maximum possible stride length. The consequence for big animals is that an increasingly larger body mass implies decreasing maximal speeds, given that the stride frequency generally decreases for increasingly larger animals. Another restriction, acting on small animals, is discussed only in preliminary terms, but it seems safe to assume from previous studies that for a given range of body masses of small animals, those which are bigger are faster. The difference between speed scaling trends for large and small animals implies the existence of a range of intermediate body masses corresponding to the fastest animals. Copyright © 2015 Elsevier Ltd. All rights reserved.

Can anti-gravity running improve performance to the same degree as over-ground running?

PubMed

Brennan, Christopher T; Jenkins, David G; Osborne, Mark A; Oyewale, Michael; Kelly, Vincent G

2018-03-11

This study examined the changes in running performance, maximal blood lactate concentrations and running kinematics between 85%BM anti-gravity (AG) running and normal over-ground (OG) running over an 8-week training period. Fifteen elite male developmental cricketers were assigned to either the AG or over-ground (CON) running group. The AG group (n = 7) ran twice a week on an AG treadmill and once per week over-ground. The CON group (n = 8) completed all sessions OG on grass. Both AG and OG training resulted in similar improvements in time trial and shuttle run performance. Maximal running performance showed moderate differences between the groups, however the AG condition resulted in less improvement. Large differences in maximal blood lactate concentrations existed with OG running resulting in greater improvements in blood lactate concentrations measured during maximal running. Moderate increases in stride length paired with moderate decreases in stride rate also resulted from AG training. The use of AG training to supplement regular OG training for performance should be used cautiously, as extended use over long periods of time could lead to altered stride mechanics and reduced blood lactate.

Gait characteristics over the course of a race in recreational marathon competitors.

PubMed

Bertram, John E A; Prebeau-Menezes, Leif; Szarko, Matthew J

2013-03-01

We analyzed gait and function of the supporting limb in participants of a marathon race at three stages: prerace, midrace (18 km), and near the end of the race (36 km). We confirmed that the most successful runners were able to maintain running speed for the duration of the race with little change in speed or gait. Speed slowed progressively during the race for those with slower race times, but stride frequency-stride length relationships remained normal for the speed they ran. These findings differ from most lab-based studies of fatigue, in which runners are forced to match a constant preset treadmill speed. Small changes in maximum ground force were seen in both slow- and fast-running participants as race end approached.

Usability of Three-dimensional Augmented Visual Cues Delivered by Smart Glasses on (Freezing of) Gait in Parkinson's Disease.

PubMed

Janssen, Sabine; Bolte, Benjamin; Nonnekes, Jorik; Bittner, Marian; Bloem, Bastiaan R; Heida, Tjitske; Zhao, Yan; van Wezel, Richard J A

2017-01-01

External cueing is a potentially effective strategy to reduce freezing of gait (FOG) in persons with Parkinson's disease (PD). Case reports suggest that three-dimensional (3D) cues might be more effective in reducing FOG than two-dimensional cues. We investigate the usability of 3D augmented reality visual cues delivered by smart glasses in comparison to conventional 3D transverse bars on the floor and auditory cueing via a metronome in reducing FOG and improving gait parameters. In laboratory experiments, 25 persons with PD and FOG performed walking tasks while wearing custom-made smart glasses under five conditions, at the end-of-dose. For two conditions, augmented visual cues (bars/staircase) were displayed via the smart glasses. The control conditions involved conventional 3D transverse bars on the floor, auditory cueing via a metronome, and no cueing. The number of FOG episodes and percentage of time spent on FOG were rated from video recordings. The stride length and its variability, cycle time and its variability, cadence, and speed were calculated from motion data collected with a motion capture suit equipped with 17 inertial measurement units. A total of 300 FOG episodes occurred in 19 out of 25 participants. There were no statistically significant differences in number of FOG episodes and percentage of time spent on FOG across the five conditions. The conventional bars increased stride length, cycle time, and stride length variability, while decreasing cadence and speed. No effects for the other conditions were found. Participants preferred the metronome most, and the augmented staircase least. They suggested to improve the comfort, esthetics, usability, field of view, and stability of the smart glasses on the head and to reduce their weight and size. In their current form, augmented visual cues delivered by smart glasses are not beneficial for persons with PD and FOG. This could be attributable to distraction, blockage of visual feedback, insufficient familiarization with the smart glasses, or display of the visual cues in the central rather than peripheral visual field. Future smart glasses are required to be more lightweight, comfortable, and user friendly to avoid distraction and blockage of sensory feedback, thus increasing usability.

Spatiotemporal characteristics of motor actions by blind long jump athletes

PubMed Central

Torralba, Miguel Angel; Padullés, José María; Losada, Jose Luis; López, Jose Luis

2017-01-01

Background Blind people depend on spatial and temporal representations to perform activities of daily living and compete in sport. Objective The aim of this study is to determine the spatiotemporal characteristics of long jumps performed by blind athletes and compare findings with those reported for sighted athletes. Methods We analysed a sample of 12 male athletes competing in the F11 Long Jump Finals at the Paralympic Games in London 2012. Performances were recorded using four high-speed cameras, and speeds were measured using a radar speed gun. The images were processed using validated image analysis software. Results The long jump run-up is shorter in blind athletes than in sighted athletes. We observed statistically significant differences for body centre of mass velocity and an increase in speed over the last three strides prior to take-off, contrasting with reports for sighted athletes and athletes with less severe visual impairment, who maintain or reduce their speed during the last stride. Stride length for the last three strides was the only spatial characteristic that was not significantly associated with effective jump distance. Blind long jumpers extend rather than shorten their last stride. Contact time with the take-off board is longer than that reported for sighted athletes. Conclusion The actions of blind long jumpers, unlike those without disabilities, do not vary their leg actions during the final runway approach for optimal placement on the take-off board. PMID:29018542

Ground reaction forces of Olympic and World Championship race walkers.

PubMed

Hanley, Brian; Bissas, Athanassios

2016-01-01

Race walking is an Olympic event where no visible loss of contact should occur and the knee must be straightened until midstance. The purpose of this study was to analyse ground reaction forces of world-class race walkers and associate them with key spatiotemporal variables. Nineteen athletes race walked along an indoor track and made contact with two force plates (1000 Hz) while being filmed using high-speed videography (100 Hz). Race walking speed was correlated with flight time (r = .46, p = .049) and flight distance (r = .69, p = .001). The knee's movement from hyperextension to flexion during late stance meant the vertical push-off force that followed midstance was smaller than the earlier loading peak (p < .001), resulting in a flattened profile. Athletes with narrower stride widths experienced reduced peak braking forces (r = .49, p = .046), peak propulsive forces (r = .54, p = .027), peak medial forces (r = .63, p = .007) and peak vertical push-off forces (r = .60, p = .011). Lower fluctuations in speed during stance were associated with higher stride frequencies (r = .69, p = .001), and highlighted the importance of avoiding too much braking in early stance. The flattened trajectory and consequential decrease in vertical propulsion might help the race walker avoid visible loss of contact (although non-visible flight times were useful in increasing stride length), while a narrow stride width was important in reducing peak forces in all three directions and could improve movement efficiency.

Women with fibromyalgia walk with an altered muscle synergy.

PubMed

Pierrynowski, Michael R; Tiidus, Peter M; Galea, Victoria

2005-11-01

Most individuals can use different movement and muscle recruitment patterns to perform a stated task but often only one pattern is selected which optimizes an unknown global objective given the individual's neuromusculoskeletal characteristics. Patients with fibromyalgia syndrome (FS), characterized by their chronic pain, reduced physical work capacity and muscular fatigue, could exhibit a different control signature compared to asymptomatic control volunteers (CV). To test this proposal, 22 women with FS, and 11 CV, were assessed in a gait analysis laboratory. Each subject walked repeatedly at self-selected slow, comfortable, and fast walking speeds. The gait analysis provided, for each walk, each subject's stride time, length, and velocity, and ground reaction force, and lower extremity joint kinematics, moments and powers. The data were then anthropometrically scaled and velocity normalized to reduce the influence of subject mass, leg length, and walking speed on the measured gait outcomes. Similarities and differences in the two groups' scaled and normalized gait patterns were then determined. Results show that FS and CV walk with externally similar stride lengths, times, and velocities, and joint angles and ground reaction forces but they use internally different muscle recruitment patterns. Specifically, FS preferentially power gait using their hip flexors instead of their ankle plantarflexors. Interestingly, CV use a similar muscle fatiguing recruitment pattern to walk fast which parallels the common complaint of fatigue reported by FS walking at comfortable speed.

Non-linear dynamics of human locomotion: effects of rhythmic auditory cueing on local dynamic stability.

PubMed

Terrier, Philippe; Dériaz, Olivier

2013-01-01

It has been observed that times series of gait parameters [stride length (SL), stride time (ST), and stride speed (SS)], exhibit long-term persistence and fractal-like properties. Synchronizing steps with rhythmic auditory stimuli modifies the persistent fluctuation pattern to anti-persistence. Another non-linear method estimates the degree of resilience of gait control to small perturbations, i.e., the local dynamic stability (LDS). The method makes use of the maximal Lyapunov exponent, which estimates how fast a non-linear system embedded in a reconstructed state space (attractor) diverges after an infinitesimal perturbation. We propose to use an instrumented treadmill to simultaneously measure basic gait parameters (time series of SL, ST, and SS from which the statistical persistence among consecutive strides can be assessed), and the trajectory of the center of pressure (from which the LDS can be estimated). In 20 healthy participants, the response to rhythmic auditory cueing (RAC) of LDS and of statistical persistence [assessed with detrended fluctuation analysis (DFA)] was compared. By analyzing the divergence curves, we observed that long-term LDS (computed as the reverse of the average logarithmic rate of divergence between the 4th and the 10th strides downstream from nearest neighbors in the reconstructed attractor) was strongly enhanced (relative change +73%). That is likely the indication of a more dampened dynamics. The change in short-term LDS (divergence over one step) was smaller (+3%). DFA results (scaling exponents) confirmed an anti-persistent pattern in ST, SL, and SS. Long-term LDS (but not short-term LDS) and scaling exponents exhibited a significant correlation between them (r = 0.7). Both phenomena probably result from the more conscious/voluntary gait control that is required by RAC. We suggest that LDS and statistical persistence should be used to evaluate the efficiency of cueing therapy in patients with neurological gait disorders.

Kinematic Analysis Quantifies Gait Abnormalities Associated with Lameness in Broiler Chickens and Identifies Evolutionary Gait Differences

PubMed Central

Caplen, Gina; Hothersall, Becky; Murrell, Joanna C.; Nicol, Christine J.; Waterman-Pearson, Avril E.; Weeks, Claire A.; Colborne, G. Robert

2012-01-01

This is the first time that gait characteristics of broiler (meat) chickens have been compared with their progenitor, jungle fowl, and the first kinematic study to report a link between broiler gait parameters and defined lameness scores. A commercial motion-capturing system recorded three-dimensional temporospatial information during walking. The hypothesis was that the gait characteristics of non-lame broilers (n = 10) would be intermediate to those of lame broilers (n = 12) and jungle fowl (n = 10, tested at two ages: immature and adult). Data analysed using multi-level models, to define an extensive range of baseline gait parameters, revealed inter-group similarities and differences. Natural selection is likely to have made jungle fowl walking gait highly efficient. Modern broiler chickens possess an unbalanced body conformation due to intense genetic selection for additional breast muscle (pectoral hypertrophy) and whole body mass. Together with rapid growth, this promotes compensatory gait adaptations to minimise energy expenditure and triggers high lameness prevalence within commercial flocks; lameness creating further disruption to the gait cycle and being an important welfare issue. Clear differences were observed between the two lines (short stance phase, little double-support, low leg lift, and little back displacement in adult jungle fowl; much double-support, high leg lift, and substantial vertical back movement in sound broilers) presumably related to mass and body conformation. Similarities included stride length and duration. Additional modifications were also identified in lame broilers (short stride length and duration, substantial lateral back movement, reduced velocity) presumably linked to musculo-skeletal abnormalities. Reduced walking velocity suggests an attempt to minimise skeletal stress and/or discomfort, while a shorter stride length and time, together with longer stance and double-support phases, are associated with instability. We envisage a key future role for this highly quantitative methodology in pain assessment (associated with broiler lameness) including experimental examination of therapeutic agent efficacy. PMID:22815823

Effect of Different Training Methods on Stride Parameters in Speed Maintenance Phase of 100-m Sprint Running.

PubMed

Cetin, Emel; Hindistan, I Ethem; Ozkaya, Y Gul

2018-05-01

Cetin, E, Hindistan, IE, Ozkaya, YG. Effect of different training methods on stride parameters in speed maintenance phase of 100-m sprint running. J Strength Cond Res 32(5): 1263-1272, 2018-This study examined the effects of 2 different training methods relevant to sloping surface on stride parameters in speed maintenance phase of 100-m sprint running. Twenty recreationally active students were assigned into one of 3 groups: combined training (Com), horizontal training (H), and control (C) group. Com group performed uphill and downhill training on a sloping surface with an angle of 4°, whereas H group trained on a horizontal surface, 3 days a week for 8 weeks. Speed maintenance and deceleration phases were divided into distances with 10-m intervals, and running time (t), running velocity (RV), step frequency (SF), and step length (SL) were measured at preexercise, and postexercise period. After 8 weeks of training program, t was shortened by 3.97% in Com group, and 2.37% in H group. Running velocity also increased for totally 100 m of running distance by 4.13 and 2.35% in Com, and H groups, respectively. At the speed maintenance phase, although t and maximal RV (RVmax) found to be statistically unaltered during overall phase, t was found to be decreased, and RVmax was preceded by 10 m in distance in both training groups. Step length was increased at 60-70 m, and SF was decreased at 70-80 m in H group. Step length was increased with concomitant decrease in SF at 80-90 m in Com group. Both training groups maintained the RVmax with a great percentage at the speed maintenance phase. In conclusion, although both training methods resulted in an increase in running time and RV, Com training method was more prominently effective method in improving RV, and this improvement was originated from the positive changes in SL during the speed maintaining phase.

Analysis of spastic gait in cervical myelopathy: Linking compression ratio to spatiotemporal and pedobarographic parameters.

PubMed

Nagai, Taro; Takahashi, Yasuhito; Endo, Kenji; Ikegami, Ryo; Ueno, Ryuichi; Yamamoto, Kengo

2018-01-01

Gait dysfunction associated with spasticity and hyperreflexia is a primary symptom in patients with compression of cervical spinal cord. The objective of this study was to link maximum compression ratio (CR) to spatiotemporal/pedobarographic parameters. Quantitative gait analysis was performed by using a pedobarograph in 75 elderly males with a wide range of cervical compression severity. CR values were characterized on T1-weighted magnetic resonance imaging (MRI). Statistical significances in gait analysis parameters (speed, cadence, stride length, step with, and toe-out angle) were evaluated among different CR groups by the non-parametric Kruskal-Wallis test followed by the Mann-Whitney U test using Bonferroni correction. The Spearman test was performed to verify correlations between CR and gait parameters. The Kruskal-Wallis test revealed significant decline in gait speed and stride length and significant increase in toe-out angle with progression of cervical compression myelopathy. The post-hoc Mann-Whitney U test showed significant differences in these parameters between the control group (0.45

Exceptional running and turning performance in a mite.

PubMed

Rubin, Samuel; Young, Maria Ho-Yan; Wright, Jonathan C; Whitaker, Dwight L; Ahn, Anna N

2016-03-01

The Southern California endemic mite Paratarsotomus macropalpis was filmed in the field on a concrete substrate and in the lab to analyze stride frequency, gait and running speed under different temperature conditions and during turning. At ground temperatures ranging from 45 to 60 °C, mites ran at a mean relative speed of 192.4 ± 2.1 body lengths (BL) s(-1), exceeding the highest previously documented value for a land animal by 12.5%. Stride frequencies were also exceptionally high (up to 135 Hz), and increased with substrate temperature. Juveniles exhibited higher relative speeds than adults and possess proportionally longer legs, which allow for greater relative stride lengths. Although mites accelerated and decelerated rapidly during straight running (7.2 ± 1.2 and -10.1 ± 2.1 m s(-2), respectively), the forces involved were comparable to those found in other animals. Paratarsotomus macropalpis employs an alternating tetrapod gait during steady running. Shallow turns were accomplished by a simple asymmetry in stride length. During tight turns, mites pivoted around the tarsus of the inside third leg (L3), which thus behaved like a grappling hook. Pivot turns were characterized by a 42% decrease in turning radius and a 40% increase in angular velocity compared with non-pivot turns. The joint angle amplitudes of the inner L2 and L3 were negligible during a pivot turn. While exceptional, running speeds in P. macropalpis approximate values predicted from inter-specific scaling relationships. © 2016. Published by The Company of Biologists Ltd.

Linear variability of gait according to socioeconomic status in elderly

PubMed Central

2016-01-01

Aim: To evaluate the linear variability of comfortable gait according to socioeconomic status in community-dwelling elderly. Method: For this cross-sectional observational study 63 self- functioning elderly were categorized according to the socioeconomic level on medium-low (n= 33, age 69.0 ± 5.0 years) and medium-high (n= 30, age 71.0 ± 6.0 years). Each participant was asked to perform comfortable gait speed for 3 min on an 40 meters elliptical circuit, recording in video five strides which were transformed into frames, determining the minimum foot clearance, maximum foot clearance and stride length. The intra-group linear variability was calculated by the coefficient of variation in percent. Results: The trajectory parameters variability is not different according to socioeconomic status with a 30% (range= 15-55%) for the minimum foot clearance and 6% (range= 3-8%) in maximum foot clearance. Meanwhile, the stride length consistently was more variable in the medium-low socioeconomic status for the overall sample (p= 0.004), female (p= 0.041) and male gender (p= 0.007), with values near 4% ​​(range = 2.5-5.0%) in the medium-low and 2% (range = 1.5-3.5%) in the medium-high. Conclusions: The intra-group linear variability is consistently higher and within reference parameters for stride length during comfortable gait for elderly belonging to medium-low socioeconomic status. This might be indicative of greater complexity and consequent motor adaptability. PMID:27546931

The gait standard deviation, a single measure of kinematic variability.

PubMed

Sangeux, Morgan; Passmore, Elyse; Graham, H Kerr; Tirosh, Oren

2016-05-01

Measurement of gait kinematic variability provides relevant clinical information in certain conditions affecting the neuromotor control of movement. In this article, we present a measure of overall gait kinematic variability, GaitSD, based on combination of waveforms' standard deviation. The waveform standard deviation is the common numerator in established indices of variability such as Kadaba's coefficient of multiple correlation or Winter's waveform coefficient of variation. Gait data were collected on typically developing children aged 6-17 years. Large number of strides was captured for each child, average 45 (SD: 11) for kinematics and 19 (SD: 5) for kinetics. We used a bootstrap procedure to determine the precision of GaitSD as a function of the number of strides processed. We compared the within-subject, stride-to-stride, variability with the, between-subject, variability of the normative pattern. Finally, we investigated the correlation between age and gait kinematic, kinetic and spatio-temporal variability. In typically developing children, the relative precision of GaitSD was 10% as soon as 6 strides were captured. As a comparison, spatio-temporal parameters required 30 strides to reach the same relative precision. The ratio stride-to-stride divided by normative pattern variability was smaller in kinematic variables (the smallest for pelvic tilt, 28%) than in kinetic and spatio-temporal variables (the largest for normalised stride length, 95%). GaitSD had a strong, negative correlation with age. We show that gait consistency may stabilise only at, or after, skeletal maturity. Copyright © 2016 Elsevier B.V. All rights reserved.

INS/EKF-based stride length, height and direction intent detection for walking assistance robots.

PubMed

Brescianini, Dario; Jung, Jun-Young; Jang, In-Hun; Park, Hyun Sub; Riener, Robert

2011-01-01

We propose an algorithm used to obtain the information on stride length, height difference, and direction based on user's intent during walking. For exoskeleton robots used to assist paraplegic patients' walking, this information is used to generate gait patterns by themselves in on-line. To obtain this information, we attach an inertial measurement unit(IMU) on crutches and apply an extended kalman filter-based error correction method to reduce the phenomena of drift due to bias of the IMU. The proposed method is verifed in real walking scenarios including walking, climbing up-stairs, and changing direction of walking with normal. © 2011 IEEE

Kinematic and kinetic comparison of barefoot and shod running in mid/forefoot and rearfoot strike runners.

PubMed

Thompson, M A; Lee, S S; Seegmiller, J; McGowan, C P

2015-05-01

Barefoot running has been associated with decreased stride length and switching from a rearfoot strike (RFS) pattern to a mid/forefoot strike (M/FFS) pattern. However, some individuals naturally contact the ground on their mid/forefoot, even when wearing cushioned running shoes. The purpose of this study was to determine if the mechanics of barefoot running by natural shod RFS runners differed from natural shod M/FFS runners. Twenty habitually shod runners (ten natural M/FFS and ten natural RFS) participated in this study. Three-dimensional motion analysis and ground reaction force data were captured as subjects ran at their preferred running speed in both barefoot and shod conditions. M/FFS experienced only a decrease in stride length when switching from shod to barefoot running. Whereas, when switching from shod to barefoot running, RFS individuals experienced a decrease in stride length, switched to a plantarflexed position at ground contact and saw reduced impact peak magnitudes. These results suggest that when barefoot, the RFS group ran similar to the M/FFS group running barefoot or shod. Copyright © 2015 Elsevier B.V. All rights reserved.

Immediate Effects of Ankle Balance Taping with Kinesiology Tape for Amateur Soccer Players with Lateral Ankle Sprain: A Randomized Cross-Over Design

PubMed Central

Kim, Myoung Kwon; Shin, Young Jun

2017-01-01

Background The objective of this study was to investigate the immediate effect on gait function when ankle balance taping is applied to amateur soccer players with lateral ankle sprain. Material/Methods A cross-over randomized design was used. Twenty-two soccer players with an ankle sprain underwent 3 interventions in a random order. Subjects were randomly assigned to ankle balance taping, placebo taping, and no taping groups. The assessment was performed using the GAITRite portable walkway system, which records the location and timing of each footfall during ambulation. Results Significant differences were found in the velocity, step length, stride length, and H-H base support among the 3 different taping methods (p<0.05). The ankle balance taping group showed significantly greater velocity, step length, and stride length in comparison to the placebo and no taping group. The ankle balance taping group showed a statistically significant decrease (p<0.05) in the H-H base support compared to the placebo and no taping groups, and the placebo group showed significantly greater velocity in comparison to the no taping group (p<0.05). Conclusions We conclude that ankle balance taping that uses kinesiology tape instantly increased the walking ability of amateur soccer players with lateral ankle sprain. Therefore, ankle balance taping is a useful alternative to prevent and treat ankle sprain of soccer players. PMID:29158472

Musical motor feedback (MMF) in walking hemiparetic stroke patients: randomized trials of gait improvement.

PubMed

Schauer, Michael; Mauritz, Karl-Heinz

2003-11-01

To demonstrate the effect of rhythmical auditory stimulation in a musical context for gait therapy in hemiparetic stroke patients, when the stimulation is played back measure by measure initiated by the patient's heel-strikes (musical motor feedback). Does this type of musical feedback improve walking more than a less specific gait therapy? The randomized controlled trial considered 23 registered stroke patients. Two groups were created by randomization: the control group received 15 sessions of conventional gait therapy and the test group received 15 therapy sessions with musical motor feedback. Inpatient rehabilitation hospital. Median post-stroke interval was 44 days and the patients were able to walk without technical aids with a speed of approximately 0.71 m/s. Gait velocity, step duration, gait symmetry, stride length and foot rollover path length (heel-on-toe-off distance). The test group showed more mean improvement than the control group: stride length increased by 18% versus 0%, symmetry deviation decreased by 58% versus 20%, walking speed increased by 27% versus 4% and rollover path length increased by 28% versus 11%. Musical motor feedback improves the stroke patient's walk in selected parameters more than conventional gait therapy. A fixed memory in the patient's mind about the song and its timing may stimulate the improvement of gait even without the presence of an external pacemaker.

An accelerometric measure of the gait pattern in horses after the administration of sublingual detomidine.

PubMed

López-Sanromán, F J; de la Riva Andrés, S; Holmbak-Petersen, R; Pérez-Nogués, M; Forés Jackson, P; Santos González, M

2014-10-01

The locomotor pattern alterations produced after the administration of a sublingual detomidine gel was measured by an accelerometric method in horses. Using a randomized two-way crossover design, all animals (n = 6) randomly received either detomidine gel or a placebo administered sublingually. A triaxial accelerometric device was used for gait assessment 15 minutes before (baseline) and every 10 minutes after each treatment for a period of 180 minutes. Eight different parameters were calculated, including speed, stride frequency, stride length, regularity, dorsoventral, propulsion, mediolateral, and total power. Force of acceleration and the three components of power were also calculated. Significant statistical differences were observed between groups in all the parameters but stride length. The majority of significant changes started between 30 and 70 minutes after drug administration and lasted for 160 minutes. This route of administration is definitely useful in horses in which a prolonged sedation is required, with stability being a major concern. Copyright © 2014 Elsevier Ltd. All rights reserved.

The effects of resisted sprint training on acceleration performance and kinematics in soccer, rugby union, and Australian football players.

PubMed

Spinks, Christopher D; Murphy, Aron J; Spinks, Warwick L; Lockie, Robert G

2007-02-01

Acceleration is a significant feature of game-deciding situations in the various codes of football. However little is known about the acceleration characteristics of football players, the effects of acceleration training, or the effectiveness of different training modalities. This study examined the effects of resisted sprint (RS) training (weighted sled towing) on acceleration performance (0-15 m), leg power (countermovement jump [CMJ], 5-bound test [5BT], and 50-cm drop jump [50DJ]), gait (foot contact time, stride length, stride frequency, step length, and flight time), and joint (shoulder, elbow, hip, and knee) kinematics in men (N = 30) currently playing soccer, rugby union, or Australian football. Gait and kinematic measurements were derived from the first and second strides of an acceleration effort. Participants were randomly assigned to 1 of 3 treatment conditions: (a) 8-week sprint training of two 1-h sessions x wk(-1) plus RS training (RS group, n = 10), (b) 8-week nonresisted sprint training program of two 1-h sessions x wk(-1) (NRS group, n = 10), or (c) control (n = 10). The results indicated that an 8-week RS training program (a) significantly improves acceleration and leg power (CMJ and 5BT) performance but is no more effective than an 8-week NRS training program, (b) significantly improves reactive strength (50DJ), and (c) has minimal impact on gait and upper- and lower-body kinematics during acceleration performance compared to an 8-week NRS training program. These findings suggest that RS training will not adversely affect acceleration kinematics and gait. Although apparently no more effective than NRS training, this training modality provides an overload stimulus to acceleration mechanics and recruitment of the hip and knee extensors, resulting in greater application of horizontal power.

Effects of a salsa dance training on balance and strength performance in older adults.

PubMed

Granacher, Urs; Muehlbauer, Thomas; Bridenbaugh, Stephanie A; Wolf, Madeleine; Roth, Ralf; Gschwind, Yves; Wolf, Irene; Mata, Rui; Kressig, Reto W

2012-01-01

Deficits in static and particularly dynamic postural control and force production have frequently been associated with an increased risk of falling in older adults. The objectives of this study were to investigate the effects of salsa dancing on measures of static/dynamic postural control and leg extensor power in seniors. Twenty-eight healthy older adults were randomly assigned to an intervention group (INT, n = 14, age 71.6 ± 5.3 years) to conduct an 8-week progressive salsa dancing programme or a control group (CON, n = 14, age 68.9 ± 4.7 years). Static postural control was measured during one-legged stance on a balance platform and dynamic postural control was obtained while walking on an instrumented walkway. Leg extensor power was assessed during a countermovement jump on a force plate. Programme compliance was excellent with participants of the INT group completing 92.5% of the dancing sessions. A tendency towards an improvement in the selected measures of static postural control was observed in the INT group as compared to the CON group. Significant group × test interactions were found for stride velocity, length and time. Post hoc analyses revealed significant increases in stride velocity and length, and concomitant decreases in stride time. However, salsa dancing did not have significant effects on various measures of gait variability and leg extensor power. Salsa proved to be a safe and feasible exercise programme for older adults accompanied with a high adherence rate. Age-related deficits in measures of static and particularly dynamic postural control can be mitigated by salsa dancing in older adults. High physical activity and fitness/mobility levels of our participants could be responsible for the nonsignificant findings in gait variability and leg extensor power. Copyright © 2012 S. Karger AG, Basel.

Decreased physical function and increased pain sensitivity in mice deficient for type IX collagen.

PubMed

Allen, Kyle D; Griffin, Timothy M; Rodriguiz, Ramona M; Wetsel, William C; Kraus, Virginia B; Huebner, Janet L; Boyd, Lawrence M; Setton, Lori A

2009-09-01

In mice with Col9a1 gene inactivation (Col9a1(-/-)), osteoarthritis (OA) and intervertebral disc degeneration develop prematurely. The aim of this study was to investigate Col9a1(-/-) mice for functional and symptomatic changes that may be associated with these pathologies. Col9a1(-/-) and wild-type mice were investigated for reflexes, functional impairment (beam walking, pole climbing, wire hang, grip strength), sensorimotor skills (rotarod), mechanical sensitivity (von Frey hair), and thermal sensitivity (hot plate/tail flick). Gait was also analyzed to determine velocity, stride frequency, symmetry, percentage stance time, stride length, and step width. Postmortem, sera obtained from the mice were analyzed for hyaluronan, and their knees and spines were graded histologically for degeneration. Col9a1(-/-) mice had compensatory gait changes, increased mechanical sensitivity, and impaired physical ability. Col9a1(-/-) mice ambulated with gaits characterized by increased percentage stance times and shorter stride lengths. These mice also had heightened mechanical sensitivity and were deficient in contact righting, wire hang, rotarod, and pole climbing tasks. Male Col9a1(-/-) mice had the highest mean serum hyaluronan levels and strong histologic evidence of cartilage erosion. Intervertebral disc degeneration was also detected, with Col9a1(-/-) mice having an increased incidence of disc tears. These data describe a Col9a1(-/-) behavioral phenotype characterized by altered gait, increased mechanical sensitivity, and impaired function. These gait and functional differences suggest that Col9a1(-/-) mice select locomotive behaviors that limit joint loads. The nature and magnitude of behavioral changes were largest in male mice, which also had the greatest evidence of knee degeneration. These findings suggest that Col9a1(-/-) mice present behavioral changes consistent with anatomic signs of OA and intervertebral disc degeneration.

Transcranial direct current stimulation associated with gait training in Parkinson's disease: A pilot randomized clinical trial.

PubMed

Costa-Ribeiro, Adriana; Maux, Ariadne; Bosford, Thamyris; Aoki, Yumi; Castro, Rebeca; Baltar, Adriana; Shirahige, Lívia; Moura Filho, Alberto; Nitsche, Michael A; Monte-Silva, Kátia

2017-04-01

The aim of this study is to investigate the effects of transcranial direct current stimulation (tDCS) combined with cueing gait training (CGT) on functional mobility in patients with Parkinson´s disease (PD). A pilot double-blind controlled, randomized clinical trial was conducted with 22 patients with PD assigned to the experimental (anodal tDCS plus CGT) and control group (sham tDCS plus CGT). The primary outcome (functional mobility) was assessed by 10-m walk test, cadence, stride length, and Timed Up and Go test. Motor impairment, bradykinesia, balance, and quality of life were analyzed as secondary outcomes. Minimal clinically important differences (MCIDs) were observed when assessing outcome data. Both groups demonstrated similar gains in all outcome measures, except for the stride length. The number of participants who showed MCID was similar between groups. The CGT provided many benefits to functional mobility, motor impairment, bradykinesia, balance, and quality of life. However, these effect magnitudes were not influenced by stimulation, but tDCS seems to prolong the effects of cueing therapy on functional mobility.

Post-stroke hemiparesis: Does chronicity, etiology, and lesion side are associated with gait pattern?

PubMed

Gama, Gabriela Lopes; Larissa, Coutinho de Lucena; Brasileiro, Ana Carolina de Azevedo Lima; Silva, Emília Márcia Gomes de Souza; Galvão, Élida Rayanne Viana Pinheiro; Maciel, Álvaro Cavalcanti; Lindquist, Ana Raquel Rodrigues

2017-07-01

Studies that evaluate gait rehabilitation programs for individuals with stroke often consider time since stroke of more than six months. In addition, most of these studies do not use lesion etiology or affected cerebral hemisphere as study factors. However, it is unknown whether these factors are associated with post-stroke motor performance after the spontaneous recovery period. To investigate whether time since stroke onset, etiology, and lesion side is associated with spatiotemporal and angular gait parameters of individuals with chronic stroke. Fifty individuals with chronic hemiparesis (20 women) were evaluated. The sample was stratified according to time since stroke (between 6 and 12 months, between 13 and 36 months, and over 36 months), affected cerebral hemisphere (left or right) and lesion etiology (ischemic and hemorrhagic). The participants were evaluated during overground walking at self-selected gait speed, and spatiotemporal and angular gait parameters were calculated. Results Differences between gait speed, stride length, hip flexion, and knee flexion were observed in subgroups stratified based on lesion etiology. Survivors of a hemorrhagic stroke exhibited more severe gait impairment. Subgroups stratified based on time since stroke only showed intergroup differences for stride length, and subgroups stratified based on affected cerebral hemisphere displayed between-group differences for swing time symmetry ratio. In order to recruit a more homogeneous sample, more accurate results were obtained and an appropriate rehabilitation program was offered, researchers and clinicians should consider that gait pattern might be associated with time since stroke, affected cerebral hemisphere and lesion etiology.

Is Moderate Intensity Cycling Sufficient to Induce Cardiorespiratory and Biomechanical Modifications of Subsequent Running?

PubMed

Walsh, Joel A; Dawber, James P; Lepers, Romuald; Brown, Marc; Stapley, Paul J

2017-04-01

Walsh, JA, Dawber, JP, Lepers, R, Brown, M, and Stapley, PJ. Is moderate intensity cycling sufficient to induce cardiorespiratory and biomechanical modifications of subsequent running? J Strength Cond Res 31(4): 1078-1086, 2017-This study sought to determine whether prior moderate intensity cycling is sufficient to influence the cardiorespiratory and biomechanical responses during subsequent running. Cardiorespiratory and biomechanical variables measured after moderate intensity cycling were compared with control running at the same intensity. Eight highly trained, competitive triathletes completed 2 separate exercise tests; (a) a 10-minute control run (no prior cycling) and, (b) a 30-minute transition run (TR) (preceded by 20-minute of variable cadence cycling, i.e., run versus cycle-run). Respiratory, breathing frequency (fb), heart rate (HR), cost of running (Cr), rate constant, stride length, and stride frequency variables were recorded, normalized, and quantified at the mean response time (MRT), third minute, 10th minute (steady state), and overall for the control run (CR) and TR. Cost of running increased (p ≤ 0.05) at all respective times during the TR. The V[Combining Dot Above]E/V[Combining Dot Above]CO2 and respiratory exchange ratio (RER) were significantly (p < 0.01) elevated at the MRT and 10th minute of the TR. Furthermore, overall mean increases were recorded for Cr, V[Combining Dot Above]E, V[Combining Dot Above]E/V[Combining Dot Above]CO2, RER, fb (p < 0.01), and HR (p ≤ 0.05) during the TR. Rate constant values for oxygen uptake were significantly different between CR and TR (0.48 ± 0.04 vs. 0.89 ± 0.15; p < 0.01). Stride length decreased across all recorded points during the TR (p ≤ 0.05) and stride frequency increased at the MRT and 3 minutes (p < 0.01). The findings suggest that at moderate intensity, prior cycling influences the cardiorespiratory response during subsequent running. Furthermore, prior cycling seems to have a sustained effect on the Cr during subsequent running.

A comparative analysis of spectral exponent estimation techniques for 1/fβ processes with applications to the analysis of stride interval time series

PubMed Central

Schaefer, Alexander; Brach, Jennifer S.; Perera, Subashan; Sejdić, Ervin

2013-01-01

Background The time evolution and complex interactions of many nonlinear systems, such as in the human body, result in fractal types of parameter outcomes that exhibit self similarity over long time scales by a power law in the frequency spectrum S(f) = 1/fβ. The scaling exponent β is thus often interpreted as a “biomarker” of relative health and decline. New Method This paper presents a thorough comparative numerical analysis of fractal characterization techniques with specific consideration given to experimentally measured gait stride interval time series. The ideal fractal signals generated in the numerical analysis are constrained under varying lengths and biases indicative of a range of physiologically conceivable fractal signals. This analysis is to complement previous investigations of fractal characteristics in healthy and pathological gait stride interval time series, with which this study is compared. Results The results of our analysis showed that the averaged wavelet coefficient method consistently yielded the most accurate results. Comparison with Existing Methods: Class dependent methods proved to be unsuitable for physiological time series. Detrended fluctuation analysis as most prevailing method in the literature exhibited large estimation variances. Conclusions The comparative numerical analysis and experimental applications provide a thorough basis for determining an appropriate and robust method for measuring and comparing a physiologically meaningful biomarker, the spectral index β. In consideration of the constraints of application, we note the significant drawbacks of detrended fluctuation analysis and conclude that the averaged wavelet coefficient method can provide reasonable consistency and accuracy for characterizing these fractal time series. PMID:24200509

A comparative analysis of spectral exponent estimation techniques for 1/f(β) processes with applications to the analysis of stride interval time series.

PubMed

Schaefer, Alexander; Brach, Jennifer S; Perera, Subashan; Sejdić, Ervin

2014-01-30

The time evolution and complex interactions of many nonlinear systems, such as in the human body, result in fractal types of parameter outcomes that exhibit self similarity over long time scales by a power law in the frequency spectrum S(f)=1/f(β). The scaling exponent β is thus often interpreted as a "biomarker" of relative health and decline. This paper presents a thorough comparative numerical analysis of fractal characterization techniques with specific consideration given to experimentally measured gait stride interval time series. The ideal fractal signals generated in the numerical analysis are constrained under varying lengths and biases indicative of a range of physiologically conceivable fractal signals. This analysis is to complement previous investigations of fractal characteristics in healthy and pathological gait stride interval time series, with which this study is compared. The results of our analysis showed that the averaged wavelet coefficient method consistently yielded the most accurate results. Class dependent methods proved to be unsuitable for physiological time series. Detrended fluctuation analysis as most prevailing method in the literature exhibited large estimation variances. The comparative numerical analysis and experimental applications provide a thorough basis for determining an appropriate and robust method for measuring and comparing a physiologically meaningful biomarker, the spectral index β. In consideration of the constraints of application, we note the significant drawbacks of detrended fluctuation analysis and conclude that the averaged wavelet coefficient method can provide reasonable consistency and accuracy for characterizing these fractal time series. Copyright © 2013 Elsevier B.V. All rights reserved.

Lower-body determinants of running economy in male and female distance runners.

PubMed

Barnes, Kyle R; Mcguigan, Michael R; Kilding, Andrew E

2014-05-01

A variety of training approaches have been shown to improve running economy in well-trained athletes. However, there is a paucity of data exploring lower-body determinants that may affect running economy and account for differences that may exist between genders. Sixty-three male and female distance runners were assessed in the laboratory for a range of metabolic, biomechanical, and neuromuscular measures potentially related to running economy (ml·kg(-1)·min(-1)) at a range of running speeds. At all common test velocities, women were more economical than men (effect size [ES] = 0.40); however, when compared in terms of relative intensity, men had better running economy (ES = 2.41). Leg stiffness (r = -0.80) and moment arm length (r = 0.90) were large-extremely largely correlated with running economy and each other (r = -0.82). Correlations between running economy and kinetic measures (peak force, peak power, and time to peak force) for both genders were unclear. The relationship in stride rate (r = -0.27 to -0.31) was in the opposite direction to that of stride length (r = 0.32-0.49), and the relationship in contact time (r = -0.21 to -0.54) was opposite of that of flight time (r = 0.06-0.74). Although both leg stiffness and moment arm length are highly related to running economy, it seems that no single lower-body measure can completely explain differences in running economy between individuals or genders. Running economy is therefore likely determined from the sum of influences from multiple lower-body attributes.

Variability of gait, bilateral coordination, and asymmetry in women with fibromyalgia.

PubMed

Heredia-Jimenez, J; Orantes-Gonzalez, E; Soto-Hermoso, V M

2016-03-01

To analyze how fibromyalgia affected the variability, asymmetry, and bilateral coordination of gait walking at comfortable and fast speeds. 65 fibromyalgia (FM) patients and 50 healthy women were analyzed. Gait analysis was performed using an instrumented walkway (GAITRite system). Average walking speed, coefficient of variation (CV) of stride length, swing time, and step width data were obtained and bilateral coordination and gait asymmetry were analyzed. FM patients presented significantly lower speeds than the healthy group. FM patients obtained significantly higher values of CV_StrideLength (p=0.04; p<0.001), CV_SwingTime (p<0.001; p<0.001), CV_StepWidth (p=0.004; p<0.001), phase coordination index (p=0.01; p=0.03), and p_CV (p<0.001; p=0.001) than the control group, walking at comfortable or fast speeds. Gait asymmetry only showed significant differences in the fast condition. FM patients walked more slowly and presented a greater variability of gait and worse bilateral coordination than healthy subjects. Gait asymmetry only showed differences in the fast condition. The variability and the bilateral coordination were particularly affected by FM in women. Therefore, variability and bilateral coordination of gait could be analyzed to complement the gait evaluation of FM patients. Copyright © 2016 Elsevier B.V. All rights reserved.

Immediate effects of adding mental practice to physical practice on the gait of individuals with Parkinson's disease: Randomized clinical trial.

PubMed

Santiago, Lorenna Marques de Melo; de Oliveira, Daniel Antunes; de Macêdo Ferreira, Louise Gabriella Lopes; de Brito Pinto, Hyanne Yasmim; Spaniol, Ana Paula; de Lucena Trigueiro, Larissa Coutinho; Ribeiro, Tatiana Souza; de Sousa, Angélica Vieira Cavalcanti; Piemonte, Maria Elisa Pimentel; Lindquist, Ana Raquel Rodrigues

2015-01-01

Mental practice has shown benefits in the rehabilitation of neurological patients, however, there is no evidence of immediate effects on gait of individuals with Parkinson's disease. Determine the effects of mental practice activity added to physical practice on the gait of individuals with Idiopathic Parkinson's Disease (IPD). 20 patients classified with stage 2 and 3, according to the Hoehn and Yahr scale were randomized into 2 groups. The experimental group (N = 10) was submitted to a single session of mental practice and physical practice gait protocol and the control group (N = 10) only to physical practice. The primary outcomes were stride length and total stance and swing time. Secondary outcomes were hip range of motion, velocity and mobility. Subjects were reassessed 10 minutes, 1 day and 7 days after the end of the session. There was no statistically significant difference between the groups. An intragroup difference was observed in velocity, stride length, hip range of motion, and mobility, as well as total stance and swing time. These results were also observed on follow-ups. Mental practice did not have a greater effect on the gait of individuals with IPD than physical practice, after a single session.

Single- and Dual-Task Balance Training Are Equally Effective in Youth

PubMed Central

Lüder, Benjamin; Kiss, Rainer; Granacher, Urs

2018-01-01

Due to maturation of the postural control system and secular declines in motor performance, adolescents experience deficits in postural control during standing and walking while concurrently performing cognitive interference tasks. Thus, adequately designed balance training programs may help to counteract these deficits. While the general effectiveness of youth balance training is well-documented, there is hardly any information available on the specific effects of single-task (ST) versus dual-task (DT) balance training. Therefore, the objectives of this study were (i) to examine static/dynamic balance performance under ST and DT conditions in adolescents and (ii) to study the effects of ST versus DT balance training on static/dynamic balance under ST and DT conditions in adolescents. Twenty-eight healthy girls and boys aged 12–13 years were randomly assigned to either 8 weeks of ST or DT balance training. Before and after training, postural sway and spatio-temporal gait parameters were registered under ST (standing/walking only) and DT conditions (standing/walking while concurrently performing an arithmetic task). At baseline, significantly slower gait speed (p < 0.001, d = 5.1), shorter stride length (p < 0.001, d = 4.8), and longer stride time (p < 0.001, d = 3.8) were found for DT compared to ST walking but not standing. Training resulted in significant pre–post decreases in DT costs for gait velocity (p < 0.001, d = 3.1), stride length (-45%, p < 0.001, d = 2.4), and stride time (-44%, p < 0.01, d = 1.9). Training did not induce any significant changes (p > 0.05, d = 0–0.1) in DT costs for all parameters of secondary task performance during standing and walking. Training produced significant pre–post increases (p = 0.001; d = 1.47) in secondary task performance while sitting. The observed increase was significantly greater for the ST training group (p = 0.04; d = 0.81). For standing, no significant changes were found over time irrespective of the experimental group. We conclude that adolescents showed impaired DT compared to ST walking but not standing. ST and DT balance training resulted in significant and similar changes in DT costs during walking. Thus, there appears to be no preference for either ST or DT balance training in adolescents. PMID:29928248

Single- and Dual-Task Balance Training Are Equally Effective in Youth.

PubMed

Lüder, Benjamin; Kiss, Rainer; Granacher, Urs

2018-01-01

Due to maturation of the postural control system and secular declines in motor performance, adolescents experience deficits in postural control during standing and walking while concurrently performing cognitive interference tasks. Thus, adequately designed balance training programs may help to counteract these deficits. While the general effectiveness of youth balance training is well-documented, there is hardly any information available on the specific effects of single-task (ST) versus dual-task (DT) balance training. Therefore, the objectives of this study were (i) to examine static/dynamic balance performance under ST and DT conditions in adolescents and (ii) to study the effects of ST versus DT balance training on static/dynamic balance under ST and DT conditions in adolescents. Twenty-eight healthy girls and boys aged 12-13 years were randomly assigned to either 8 weeks of ST or DT balance training. Before and after training, postural sway and spatio-temporal gait parameters were registered under ST (standing/walking only) and DT conditions (standing/walking while concurrently performing an arithmetic task). At baseline, significantly slower gait speed ( p < 0.001, d = 5.1), shorter stride length ( p < 0.001, d = 4.8), and longer stride time ( p < 0.001, d = 3.8) were found for DT compared to ST walking but not standing. Training resulted in significant pre-post decreases in DT costs for gait velocity ( p < 0.001, d = 3.1), stride length (-45%, p < 0.001, d = 2.4), and stride time (-44%, p < 0.01, d = 1.9). Training did not induce any significant changes ( p > 0.05, d = 0-0.1) in DT costs for all parameters of secondary task performance during standing and walking. Training produced significant pre-post increases ( p = 0.001; d = 1.47) in secondary task performance while sitting. The observed increase was significantly greater for the ST training group ( p = 0.04; d = 0.81). For standing, no significant changes were found over time irrespective of the experimental group. We conclude that adolescents showed impaired DT compared to ST walking but not standing. ST and DT balance training resulted in significant and similar changes in DT costs during walking. Thus, there appears to be no preference for either ST or DT balance training in adolescents.

Automated health alerts from Kinect-based in-home gait measurements.

PubMed

Stone, Erik E; Skubic, Marjorie; Back, Jessica

2014-01-01

A method for automatically generating alerts to clinicians in response to changes in in-home gait parameters is investigated. Kinect-based gait measurement systems were installed in apartments in a senior living facility. The systems continuously monitored the walking speed, stride time, and stride length of apartment residents. A framework for modeling uncertainty in the residents' gait parameter estimates, which is critical for robust change detection, is developed; along with an algorithm for detecting changes that may be clinically relevant. Three retrospective case studies, of individuals who had their gait monitored for periods ranging from 12 to 29 months, are presented to illustrate use of the alert method. Evidence suggests that clinicians could be alerted to health changes at an early stage, while they are still small and interventions may be most successful. Additional potential uses are also discussed.

The effect of racetrack design on gait symmetry of the pacer.

PubMed Central

Crawford, W H; Leach, D H

1984-01-01

A survey of a western Canadian racetrack determined the superelevation and transition curves to be less than the cited design standards. High-speed cinematography was used to film seven Standardbred pacers as they proceeded around one curve of the track at racing speed and for each horse 19 temporal stride parameters were obtained from these films using a film analyzer system. Average velocities were calculated and the mean stride length was found to vary from 5.08 m to 5.77 m. In all frames analyzed the hind foot was observed to contact the track surface prior to the ipsilateral forefoot and all horses displayed significant (p less than 0.05) contralateral asymmetry of some temporal stride parameters. Fifteen temporal stride parameters were significantly different (p less than 0.05) when compared between horses but only three temporal stride parameters were significantly different (p less than 0.05) when their values were compared between segments of the curved portions of the track. It is suggested that temporal gait asymmetry should not be used to judge the standards of racetrack design. PMID:6509365

The effect of racetrack design on gait symmetry of the pacer.

PubMed

Crawford, W H; Leach, D H

1984-10-01

A survey of a western Canadian racetrack determined the superelevation and transition curves to be less than the cited design standards. High-speed cinematography was used to film seven Standardbred pacers as they proceeded around one curve of the track at racing speed and for each horse 19 temporal stride parameters were obtained from these films using a film analyzer system. Average velocities were calculated and the mean stride length was found to vary from 5.08 m to 5.77 m. In all frames analyzed the hind foot was observed to contact the track surface prior to the ipsilateral forefoot and all horses displayed significant (p less than 0.05) contralateral asymmetry of some temporal stride parameters. Fifteen temporal stride parameters were significantly different (p less than 0.05) when compared between horses but only three temporal stride parameters were significantly different (p less than 0.05) when their values were compared between segments of the curved portions of the track. It is suggested that temporal gait asymmetry should not be used to judge the standards of racetrack design.

Effects of a wearable exoskeleton stride management assist system (SMA®) on spatiotemporal gait characteristics in individuals after stroke: a randomized controlled trial.

PubMed

Buesing, Carolyn; Fisch, Gabriela; O'Donnell, Megan; Shahidi, Ida; Thomas, Lauren; Mummidisetty, Chaithanya K; Williams, Kenton J; Takahashi, Hideaki; Rymer, William Zev; Jayaraman, Arun

2015-08-20

Robots offer an alternative, potentially advantageous method of providing repetitive, high-dosage, and high-intensity training to address the gait impairments caused by stroke. In this study, we compared the effects of the Stride Management Assist (SMA®) System, a new wearable robotic device developed by Honda R&D Corporation, Japan, with functional task specific training (FTST) on spatiotemporal gait parameters in stroke survivors. A single blinded randomized control trial was performed to assess the effect of FTST and task-specific walking training with the SMA® device on spatiotemporal gait parameters. Participants (n=50) were randomly assigned to FTST or SMA. Subjects in both groups received training 3 times per week for 6-8 weeks for a maximum of 18 training sessions. The GAITRite® system was used to collect data on subjects' spatiotemporal gait characteristics before training (baseline), at mid-training, post-training, and at a 3-month follow-up. After training, significant improvements in gait parameters were observed in both training groups compared to baseline, including an increase in velocity and cadence, a decrease in swing time on the impaired side, a decrease in double support time, an increase in stride length on impaired and non-impaired sides, and an increase in step length on impaired and non-impaired sides. No significant differences were observed between training groups; except for SMA group, step length on the impaired side increased significantly during self-selected walking speed trials and spatial asymmetry decreased significantly during fast-velocity walking trials. SMA and FTST interventions provided similar, significant improvements in spatiotemporal gait parameters; however, the SMA group showed additional improvements across more parameters at various time points. These results indicate that the SMA® device could be a useful therapeutic tool to improve spatiotemporal parameters and contribute to improved functional mobility in stroke survivors. Further research is needed to determine the feasibility of using this device in a home setting vs a clinic setting, and whether such home use provides continued benefits. This study is registered under the title "Development of walk assist device to improve community ambulation" and can be located in clinicaltrials.gov with the study identifier: NCT01994395 .

Usability of Three-dimensional Augmented Visual Cues Delivered by Smart Glasses on (Freezing of) Gait in Parkinson’s Disease

PubMed Central

Janssen, Sabine; Bolte, Benjamin; Nonnekes, Jorik; Bittner, Marian; Bloem, Bastiaan R.; Heida, Tjitske; Zhao, Yan; van Wezel, Richard J. A.

2017-01-01

External cueing is a potentially effective strategy to reduce freezing of gait (FOG) in persons with Parkinson’s disease (PD). Case reports suggest that three-dimensional (3D) cues might be more effective in reducing FOG than two-dimensional cues. We investigate the usability of 3D augmented reality visual cues delivered by smart glasses in comparison to conventional 3D transverse bars on the floor and auditory cueing via a metronome in reducing FOG and improving gait parameters. In laboratory experiments, 25 persons with PD and FOG performed walking tasks while wearing custom-made smart glasses under five conditions, at the end-of-dose. For two conditions, augmented visual cues (bars/staircase) were displayed via the smart glasses. The control conditions involved conventional 3D transverse bars on the floor, auditory cueing via a metronome, and no cueing. The number of FOG episodes and percentage of time spent on FOG were rated from video recordings. The stride length and its variability, cycle time and its variability, cadence, and speed were calculated from motion data collected with a motion capture suit equipped with 17 inertial measurement units. A total of 300 FOG episodes occurred in 19 out of 25 participants. There were no statistically significant differences in number of FOG episodes and percentage of time spent on FOG across the five conditions. The conventional bars increased stride length, cycle time, and stride length variability, while decreasing cadence and speed. No effects for the other conditions were found. Participants preferred the metronome most, and the augmented staircase least. They suggested to improve the comfort, esthetics, usability, field of view, and stability of the smart glasses on the head and to reduce their weight and size. In their current form, augmented visual cues delivered by smart glasses are not beneficial for persons with PD and FOG. This could be attributable to distraction, blockage of visual feedback, insufficient familiarization with the smart glasses, or display of the visual cues in the central rather than peripheral visual field. Future smart glasses are required to be more lightweight, comfortable, and user friendly to avoid distraction and blockage of sensory feedback, thus increasing usability. PMID:28659862

Comparison of transtibial amputee and non-amputee biomechanics during a common turning task.

PubMed

Segal, Ava D; Orendurff, Michael S; Czerniecki, Joseph M; Schoen, Jason; Klute, Glenn K

2011-01-01

The biomechanics of amputee turning gait has been minimally studied, in spite of its integral relationship with the more complex gait required for household or community ambulation. This study compares the biomechanics of unilateral transtibial amputees and non-amputees completing a common turning task. Full body gait analysis was completed for subjects walking at comparable self-selected speeds around a 1m radius circular path. Peak internal and external rotation moments of the hip, knee and ankle, mediolateral ground reaction impulse (ML GRI), peak effective limb length, and stride length were compared across conditions (non-amputee, amputee prosthetic limb, amputee sound limb). Amputees showed decreased internal rotation moments at the prosthetic limb hip and knee compared to non-amputees, perhaps as a protective mechanism to minimize stress on the residual limb. There was also an increase in amputee sound limb hip external rotation moment in early stance compared to non-amputees, which may be a compensation for the decrease in prosthetic limb internal rotation moment during late stance of the prior step. ML GRI was decreased for the amputee inside limb compared to non-amputee, possibly to minimize the body's acceleration in the direction of the turn. Amputees also exhibited a shorter inside limb stride length compared to non-amputees. Both decreased ML GRI and stride length indicate a COM that is more centered over the base of support, which may minimize the risk of falling. Finally, a longer effective limb length was found for the amputee inside limb turning, possibly due to excessive trunk shift. Published by Elsevier B.V.

Effect of step-synchronized vibration stimulation of soles on gait in Parkinson's disease: a pilot study.

PubMed

Novak, Peter; Novak, Vera

2006-05-04

Previous studies have suggested that impaired proprioceptive processing in the striatum may contribute to abnormal gait in Parkinson's disease (PD). This pilot study assessed the effects of enhanced proprioceptive feedback using step-synchronized vibration stimulation of the soles (S-VS) on gait in PD. S-VS was used in 8 PD subjects (3 women and 5 men, age range 44-79 years, on medication) and 8 age-matched healthy subjects (5 women and 3 men). PD subjects had mild or moderate gait impairment associated with abnormal balance, but they did not have gait freezing. Three vibratory devices (VDs) were embedded in elastic insoles (one below the heel and two below the forefoot areas) inserted into the shoes. Each VD operates independently and has a pressure switch that activates the underlying vibratory actuator. The VD delivered the 70-Hz suprathreshold vibration pulse upon touch by the heel or forefoot, and the vibration pulse was deactivated upon respective push-offs. Six-minute hallway walking was studied with and without S-VS. Gait characteristics were measured using the force-sensitive foot switches. The primary outcome was the stride variability expressed as a coefficient of variation (CV), a measure of gait steadiness. Secondary outcome measures were walking distance and speed, stride length and duration, cadence, stance, swing and double support duration, and respective CVs (if applicable). The walking speed (p < 0.04) and the CV of the stride interval (p < 0.02) differed between the groups and S-VS conditions. In the PD group, S-VS decreased stride variability (p < 0.002), increased walking speed (p < 0.0001), stride duration (p < 0.01), stride length (p < 0.0002), and cadence (p < 0.03). In the control group, S-VS decreased stride variability (p < 0.006) and increased gait speed (p < 0.03), but other locomotion parameters were not significantly altered. Augmented sensory feedback improves parkinsonian gait steadiness in the short-term setting. Because the suprathreshold stimulation prevented blinding of subjects, the learning effect and increased attention can be a confounding factor underlying results. Long-term studies are needed to establish the clinical value of the S-VS.

Is There an Economical Running Technique? A Review of Modifiable Biomechanical Factors Affecting Running Economy.

PubMed

Moore, Isabel S

2016-06-01

Running economy (RE) has a strong relationship with running performance, and modifiable running biomechanics are a determining factor of RE. The purposes of this review were to (1) examine the intrinsic and extrinsic modifiable biomechanical factors affecting RE; (2) assess training-induced changes in RE and running biomechanics; (3) evaluate whether an economical running technique can be recommended and; (4) discuss potential areas for future research. Based on current evidence, the intrinsic factors that appeared beneficial for RE were using a preferred stride length range, which allows for stride length deviations up to 3 % shorter than preferred stride length; lower vertical oscillation; greater leg stiffness; low lower limb moment of inertia; less leg extension at toe-off; larger stride angles; alignment of the ground reaction force and leg axis during propulsion; maintaining arm swing; low thigh antagonist-agonist muscular coactivation; and low activation of lower limb muscles during propulsion. Extrinsic factors associated with a better RE were a firm, compliant shoe-surface interaction and being barefoot or wearing lightweight shoes. Several other modifiable biomechanical factors presented inconsistent relationships with RE. Running biomechanics during ground contact appeared to play an important role, specifically those during propulsion. Therefore, this phase has the strongest direct links with RE. Recurring methodological problems exist within the literature, such as cross-comparisons, assessing variables in isolation, and acute to short-term interventions. Therefore, recommending a general economical running technique should be approached with caution. Future work should focus on interdisciplinary longitudinal investigations combining RE, kinematics, kinetics, and neuromuscular and anatomical aspects, as well as applying a synergistic approach to understanding the role of kinetics.

Effects of adding a virtual reality environment to different modes of treadmill walking.

PubMed

Sloot, L H; van der Krogt, M M; Harlaar, J

2014-03-01

Differences in gait between overground and treadmill walking are suggested to result from imposed treadmill speed and lack of visual flow. To counteract this effect, feedback-controlled treadmills that allow the subject to control the belt speed along with an immersive virtual reality (VR) have recently been developed. We studied the effect of adding a VR during both fixed speed (FS) and self-paced (SP) treadmill walking. Nineteen subjects walked on a dual-belt instrumented treadmill with a simple endless road projected on a 180° circular screen. A main effect of VR was found for hip flexion offset, peak hip extension, peak knee extension moment, knee flexion moment gain and ankle power during push off. A consistent interaction effect between VR and treadmill mode was found for 12 out of 30 parameters, although the differences were small and did not exceed 50% of the within subject stride variance. At FS, the VR seemed to slightly improve the walking pattern towards overground walking, with for example a 6.5mm increase in stride length. At SP, gait became slightly more cautious by adding a VR, with a 9.1mm decrease in stride length. Irrespective of treadmill mode, subjects rated walking with the VR as more similar to overground walking. In the context of clinical gait analysis, the effects of VR are too small to be relevant and are outweighed by the gains of adding a VR, such as a more stimulating experience and possibility of augmenting it by real-time feedback. Copyright © 2013 Elsevier B.V. All rights reserved.

Differential Effect of Helicobacter pylori Eradication on Time-Trends in Brady/Hypokinesia and Rigidity in Idiopathic Parkinsonism

PubMed Central

Dobbs, Sylvia M; Dobbs, R John; Weller, Clive; Charlett, André; Bjarnason, Ingvar T; Lawson, Andrew J; Letley, Darren; Harbin, Lucy; Price, Ashley B; Ibrahim, Mohammad A A; Oxlade, Norman L; Bowthorpe, James; Leckstroem, Daniel; Smee, Cori; Plant, J Malcolm; Peterson, Dale W

2010-01-01

Background: We examine the effect of eradicating Helicobacter in idiopathic parkinsonism (IP). Marked deterioration, where eradication-therapy failed, prompted an interim report in the first 20 probands to reach de-blinding. The null-hypothesis, “eradication has no effect on principal outcome, mean stride length at free-walking speed,” was rejected. We report on study completion in all 30 who had commenced post-treatment assessments. Methods: This is a randomized, placebo-controlled, parallel-group efficacy study of eradicating biopsy-proven (culture and/or organism on histopathology) Helicobacter pylori infection on the time course of facets of IP, in probands taking no, or stable long-t½, anti-parkinsonian medication. Persistent infection at de-blinding (scheduled 1-year post-treatment) led to open active eradication-treatment. Results: Stride length improved (73 (95% CI 14–131) mm/year, p = .01) in favor of “successful” blinded active over placebo, irrespective of anti-parkinsonian medication, and despite worsening upper limb flexor rigidity (237 (57–416) Nm × 10−3/year, p = .01). This differential effect was echoed following open active, post-placebo. Gait did not deteriorate in year 2 and 3 post-eradication. Anti-nuclear antibody was present in all four proven (two by molecular microbiology only) eradication failures. In the remainder, it marked poorer response during the year after eradication therapy, possibly indicating residual “low-density” infection. We illustrate the importance of eradicating low-density infection, detected only by molecular microbiology, in a proband not receiving anti-parkinsonian medication. Stride length improved (424 (379–468) mm for 15 months post-eradication, p = .001), correction of deficit continuing to 3.4 years. Flexor rigidity increased before hydrogen-breath-test positivity for small intestinal bacterial overgrowth (208 (28–388) Nm × 10−3, p = .02), increased further during (171 (67–274), p = .001) (15–31 months), and decreased (136 (6–267), p = .04) after restoration of negativity (32–41 months). Conclusion: Helicobacter is an arbiter of progression, independent of infection-load. PMID:20633189

Kinematics gait disorder in men with fibromyalgia.

PubMed

Heredia-Jimenez, Jose M; Soto-Hermoso, Victor M

2014-01-01

The aim of this study was to assess the kinematics disorder of gait in men with fibromyalgia. We studied 12 male with fibromyalgia and 14 healthy men. Each participant of the study walked five trials along a 18.6-m walkway. Fibromyalgia patients completed a Spanish version of Fibromyalgia Impact Questionnaire. Significant differences between fibromyalgia and control groups were found in velocity, stride length, and cadence. Gait parameters of men affected by fibromyalgia were impaired when compared to those of healthy group due to bradykinesia. According to previous studies to assess gait variables in female patients, the male with fibromyalgia also showed lower values of velocity, cadence, and stride length than healthy group but not reported significant differences in swing, stance, single, or double support phase.

Partial body weight support treadmill training speed influences paretic and non-paretic leg muscle activation, stride characteristics, and ratings of perceived exertion during acute stroke rehabilitation.

PubMed

Burnfield, Judith M; Buster, Thad W; Goldman, Amy J; Corbridge, Laura M; Harper-Hanigan, Kellee

2016-06-01

Intensive task-specific training is promoted as one approach for facilitating neural plastic brain changes and associated motor behavior gains following neurologic injury. Partial body weight support treadmill training (PBWSTT), is one task-specific approach frequently used to improve walking during the acute period of stroke recovery (<1month post infarct). However, only limited data have been published regarding the relationship between training parameters and physiologic demands during this early recovery phase. To examine the impact of four walking speeds on stride characteristics, lower extremity muscle demands (both paretic and non-paretic), Borg ratings of perceived exertion (RPE), and blood pressure. A prospective, repeated measures design was used. Ten inpatients post unilateral stroke participated. Following three familiarization sessions, participants engaged in PBWSTT at four predetermined speeds (0.5, 1.0, 1.5 and 2.0mph) while bilateral electromyographic and stride characteristic data were recorded. RPE was evaluated immediately following each trial. Stride length, cadence, and paretic single limb support increased with faster walking speeds (p⩽0.001), while non-paretic single limb support remained nearly constant. Faster walking resulted in greater peak and mean muscle activation in the paretic medial hamstrings, vastus lateralis and medial gastrocnemius, and non-paretic medial gastrocnemius (p⩽0.001). RPE also was greatest at the fastest compared to two slowest speeds (p<0.05). During the acute phase of stroke recovery, PBWSTT at the fastest speed (2.0mph) promoted practice of a more optimal gait pattern with greater intensity of effort as evidenced by the longer stride length, increased between-limb symmetry, greater muscle activation, and higher RPE compared to training at the slowest speeds. Copyright © 2016 Elsevier B.V. All rights reserved.

Recommended number of strides for automatic assessment of gait symmetry and regularity in above-knee amputees by means of accelerometry and autocorrelation analysis

PubMed Central

2012-01-01

Background Symmetry and regularity of gait are essential outcomes of gait retraining programs, especially in lower-limb amputees. This study aims presenting an algorithm to automatically compute symmetry and regularity indices, and assessing the minimum number of strides for appropriate evaluation of gait symmetry and regularity through autocorrelation of acceleration signals. Methods Ten transfemoral amputees (AMP) and ten control subjects (CTRL) were studied. Subjects wore an accelerometer and were asked to walk for 70 m at their natural speed (twice). Reference values of step and stride regularity indices (Ad1 and Ad2) were obtained by autocorrelation analysis of the vertical and antero-posterior acceleration signals, excluding initial and final strides. The Ad1 and Ad2 coefficients were then computed at different stages by analyzing increasing portions of the signals (considering both the signals cleaned by initial and final strides, and the whole signals). At each stage, the difference between Ad1 and Ad2 values and the corresponding reference values were compared with the minimum detectable difference, MDD, of the index. If that difference was less than MDD, it was assumed that the portion of signal used in the analysis was of sufficient length to allow reliable estimation of the autocorrelation coefficient. Results All Ad1 and Ad2 indices were lower in AMP than in CTRL (P < 0.0001). Excluding initial and final strides from the analysis, the minimum number of strides needed for reliable computation of step symmetry and stride regularity was about 2.2 and 3.5, respectively. Analyzing the whole signals, the minimum number of strides increased to about 15 and 20, respectively. Conclusions Without the need to identify and eliminate the phases of gait initiation and termination, twenty strides can provide a reasonable amount of information to reliably estimate gait regularity in transfemoral amputees. PMID:22316184

Effect of noise and filtering on largest Lyapunov exponent of time series associated with human walking.

PubMed

Mehdizadeh, Sina; Sanjari, Mohammad Ali

2017-11-07

This study aimed to determine the effect of added noise, filtering and time series length on the largest Lyapunov exponent (LyE) value calculated for time series obtained from a passive dynamic walker. The simplest passive dynamic walker model comprising of two massless legs connected by a frictionless hinge joint at the hip was adopted to generate walking time series. The generated time series was used to construct a state space with the embedding dimension of 3 and time delay of 100 samples. The LyE was calculated as the exponential rate of divergence of neighboring trajectories of the state space using Rosenstein's algorithm. To determine the effect of noise on LyE values, seven levels of Gaussian white noise (SNR=55-25dB with 5dB steps) were added to the time series. In addition, the filtering was performed using a range of cutoff frequencies from 3Hz to 19Hz with 2Hz steps. The LyE was calculated for both noise-free and noisy time series with different lengths of 6, 50, 100 and 150 strides. Results demonstrated a high percent error in the presence of noise for LyE. Therefore, these observations suggest that Rosenstein's algorithm might not perform well in the presence of added experimental noise. Furthermore, findings indicated that at least 50 walking strides are required to calculate LyE to account for the effect of noise. Finally, observations support that a conservative filtering of the time series with a high cutoff frequency might be more appropriate prior to calculating LyE. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of constrained arm swing on vertical center of mass displacement during walking.

PubMed

Yang, Hyung Suk; Atkins, Lee T; Jensen, Daniel B; James, C Roger

2015-10-01

The purpose of this study was to determine the effects of constraining arm swing on the vertical displacement of the body's center of mass (COM) during treadmill walking and examine several common gait variables that may account for or mask differences in the body's COM motion with and without arm swing. Participants included 20 healthy individuals (10 male, 10 female; age: 27.8 ± 6.8 years). The body's COM displacement, first and second peak vertical ground reaction forces (VGRFs), and lowest VGRF during mid-stance, peak summed bilateral VGRF, lower extremity sagittal joint angles, stride length, and foot contact time were measured with and without arm swing during walking at 1.34 m/s. The body's COM displacement was greater with the arms constrained (arm swing: 4.1 ± 1.2 cm, arm constrained: 4.9 ± 1.2 cm, p < 0.001). Ground reaction force data indicated that the COM displacement increased in both double limb and single limb stance. However, kinematic patterns visually appeared similar between conditions. Shortened stride length and foot contact time also were observed, although these do not seem to account for the increased COM displacement. However, a change in arm COM acceleration might have contributed to the difference. These findings indicate that a change in arm swing causes differences in vertical COM displacement, which could increase energy expenditure. Copyright © 2015 Elsevier B.V. All rights reserved.

Detrended Fluctuation Analysis and Adaptive Fractal Analysis of Stride Time Data in Parkinson's Disease: Stitching Together Short Gait Trials

PubMed Central

Liebherr, Magnus; Haas, Christian T.

2014-01-01

Variability indicates motor control disturbances and is suitable to identify gait pathologies. It can be quantified by linear parameters (amplitude estimators) and more sophisticated nonlinear methods (structural information). Detrended Fluctuation Analysis (DFA) is one method to measure structural information, e.g., from stride time series. Recently, an improved method, Adaptive Fractal Analysis (AFA), has been proposed. This method has not been applied to gait data before. Fractal scaling methods (FS) require long stride-to-stride data to obtain valid results. However, in clinical studies, it is not usual to measure a large number of strides (e.g., strides). Amongst others, clinical gait analysis is limited due to short walkways, thus, FS seem to be inapplicable. The purpose of the present study was to evaluate FS under clinical conditions. Stride time data of five self-paced walking trials ( strides each) of subjects with PD and a healthy control group (CG) was measured. To generate longer time series, stride time sequences were stitched together. The coefficient of variation (CV), fractal scaling exponents (DFA) and (AFA) were calculated. Two surrogate tests were performed: A) the whole time series was randomly shuffled; B) the single trials were randomly shuffled separately and afterwards stitched together. CV did not discriminate between PD and CG. However, significant differences between PD and CG were found concerning and . Surrogate version B yielded a higher mean squared error and empirical quantiles than version A. Hence, we conclude that the stitching procedure creates an artificial structure resulting in an overestimation of true . The method of stitching together sections of gait seems to be appropriate in order to distinguish between PD and CG with FS. It provides an approach to integrate FS as standard in clinical gait analysis and to overcome limitations such as short walkways. PMID:24465708

Effect of step-synchronized vibration stimulation of soles on gait in Parkinson's disease: a pilot study

PubMed Central

Novak, Peter; Novak, Vera

2006-01-01

Background Previous studies have suggested that impaired proprioceptive processing in the striatum may contribute to abnormal gait in Parkinson's disease (PD). Methods This pilot study assessed the effects of enhanced proprioceptive feedback using step-synchronized vibration stimulation of the soles (S-VS) on gait in PD. S-VS was used in 8 PD subjects (3 women and 5 men, age range 44–79 years, on medication) and 8 age-matched healthy subjects (5 women and 3 men). PD subjects had mild or moderate gait impairment associated with abnormal balance, but they did not have gait freezing. Three vibratory devices (VDs) were embedded in elastic insoles (one below the heel and two below the forefoot areas) inserted into the shoes. Each VD operates independently and has a pressure switch that activates the underlying vibratory actuator. The VD delivered the 70-Hz suprathreshold vibration pulse upon touch by the heel or forefoot, and the vibration pulse was deactivated upon respective push-offs. Six-minute hallway walking was studied with and without S-VS. Gait characteristics were measured using the force-sensitive foot switches. The primary outcome was the stride variability expressed as a coefficient of variation (CV), a measure of gait steadiness. Secondary outcome measures were walking distance and speed, stride length and duration, cadence, stance, swing and double support duration, and respective CVs (if applicable). Results The walking speed (p < 0.04) and the CV of the stride interval (p < 0.02) differed between the groups and S-VS conditions. In the PD group, S-VS decreased stride variability (p < 0.002), increased walking speed (p < 0.0001), stride duration (p < 0.01), stride length (p < 0.0002), and cadence (p < 0.03). In the control group, S-VS decreased stride variability (p < 0.006) and increased gait speed (p < 0.03), but other locomotion parameters were not significantly altered. Conclusion Augmented sensory feedback improves parkinsonian gait steadiness in the short-term setting. Because the suprathreshold stimulation prevented blinding of subjects, the learning effect and increased attention can be a confounding factor underlying results. Long-term studies are needed to establish the clinical value of the S-VS. PMID:16674823

Separating Fact from Fiction: Increasing Running Speed

ERIC Educational Resources Information Center

Murgia, Carla

2008-01-01

From a biomechanical point of view, this article explores the common belief that one must increase stride length and frequency in order to increase running speed. The limb length, explosive power, and anaerobic capacity of the athlete, as well as the type of running (sprinting vs. long distance) must be considered before making such a…

A study on a robot chasing a human using Kinect while identifying walking parameters using the back view

NASA Astrophysics Data System (ADS)

Konno, S.; Mita, A.

2014-03-01

Recently, the demand of the building spaces to respond to increase of single aged households and the diversification of life style is increasing. Smart house is one of them, but it is difficult for them to be changed and renovated. Therefore, we suggest Biofied builing. In biofied building, we use a mobile robot to get concious and unconcious information about residents and try to make it more secure and comfort builing spaces by realizing the intraction between residents and builing spaces. Walking parameters are one of the most important unconscious information about residents. They are an indicator of autonomy of elderly, and changes of stride length and walking speed may be pridictive of a future fall and a cognitive impairment. By observing their walking and informing residents their walking state, they can forestall such dangers and it helps them to live more securely and autonomously. Many methods to estimate walking parameters have been studied. The famous ones are to use accelerometers and a motion capture camera. Walking parameters estimated by them are high precise but the sensors are attached to a human body in these method and it can make human's walk different from the original walk. Furthermore, some elderly feel it to invade them. In this work, Kinect which can get information about human untouchably was used on the mobile robot. A stride time, stride length, and walking speed were estimated from the back view of human by following him or her. Evaluation was done for 10m, 5m, 4m, and 3m in whole walking. As a result, the proposal system can estimate walking parameters of the walk more than 3m.

Softer, higher-friction flooring improves gait of cows with and without sole ulcers.

PubMed

Flower, F C; de Passillé, A M; Weary, D M; Sanderson, D J; Rushen, J

2007-03-01

We studied dairy cows (n = 30) walking on concrete and on a soft, high-friction composite rubber surface to examine how flooring influenced gait and how this differed for cows with hoof lesions. Cows had hooves trimmed 9 wk after the trial and were classified as either with or without sole ulcers. Video recordings of the cows while walking were digitized using motion analysis software to calculate stride variables (length, height, overlap, duration, proportion of triple support, and speed). Gait was scored by a subjective scoring system (1 = sound to 5 = severely lame) and by a continuous visual analog scale for each of 7 gait attributes. Cows with sole ulcers walking on a composite rubber surface had longer strides (156.9 +/- 2.6 vs. 149.6 +/- 2.6 cm), higher stride heights (9.7 +/- 0.3 vs. 8.8 +/- 0.3 cm), more stride overlap (0.4 +/- 2.0 vs. -4.3 +/- 2.0 cm), shorter periods of triple support (3 legs in ground contact; 68.6 +/- 2.0 vs. 73.8 +/- 2.0%), walked faster (1.22 +/- 0.04 vs. 1.17 +/- 0.04 m/s) and had lower overall gait scores (2.9 +/- 0.1 vs. 3.1 +/- 0.1), better tracking-up (19 +/- 2 vs. 24 +/- 2), better joint flexion (29 +/- 2 vs. 33 +/- 2), more symmetric steps (31 +/- 3 vs. 36 +/- 3), and less reluctance to bear weight on their legs (12 +/- 2 vs. 16 +/- 2) compared with walking on concrete. Similar results were found for cows without sole ulcers. Most of the subjective gait measures could distinguish between cows with and without sole ulcers, but this was not the case for kinematic measures other than stride height. Cows with higher gait scores (more severe lameness) showed the greatest improvement in stride length (r = -0.51), triple support (r = 0.59), swing duration (r = -0.44), overall gait score (r = 0.46), and reluctance to bear weight (r = 0.66) when walking on the rubber surface compared with cows with lower gait scores. These results indicate that rubber flooring provides a more secure footing and is more comfortable to walk on, especially for lame cattle.

Gait Parameter Adjustments for Walking on a Treadmill at Preferred, Slower, and Faster Speeds in Older Adults with Down Syndrome

PubMed Central

Smith, Beth A.; Kubo, Masayoshi; Ulrich, Beverly D.

2012-01-01

The combined effects of ligamentous laxity, hypotonia, and decrements associated with aging lead to stability-enhancing foot placement adaptations during routine overground walking at a younger age in adults with Down syndrome (DS) compared to their peers with typical development (TD). Our purpose here was to examine real-time adaptations in older adults with DS by testing their responses to walking on a treadmill at their preferred speed and at speeds slower and faster than preferred. We found that older adults with DS were able to adapt their gait to slower and faster than preferred treadmill speeds; however, they maintained their stability-enhancing foot placements at all speeds compared to their peers with TD. All adults adapted their gait patterns similarly in response to faster and slower than preferred treadmill-walking speeds. They increased stride frequency and stride length, maintained step width, and decreased percent stance as treadmill speed increased. Older adults with DS, however, adjusted their stride frequencies significantly less than their peers with TD. Our results show that older adults with DS have the capacity to adapt their gait parameters in response to different walking speeds while also supporting the need for intervention to increase gait stability. PMID:22693497

Spatiotemporal Gait Characteristics Associated with Cognitive Impairment: A Multicenter Cross-Sectional Study, the Intercontinental "Gait, cOgnitiOn & Decline" Initiative.

PubMed

Beauchet, Olivier; Blumen, Helena M; Callisaya, Michele L; De Cock, Anne-Marie; Kressig, Reto W; Srikanth, Velandai; Steinmetz, Jean-Paul; Verghese, Joe; Allali, Gilles

2018-01-23

The study aims to determine the spatiotemporal gait parameters and/or their combination(s) that best differentiate between cognitively healthy individuals (CHI), patients with mild cognitive impairment (MCI) and those with mild and moderate dementia, regardless of the etiology of cognitive impairment. A total of 2099 participants (1015 CHI, 478 patients with MCI, 331 patients with mild dementia and 275 with moderate dementia) were selected from the intercontinental "Gait, cOgnitiOn & Decline" (GOOD) initiative, which merged different databases from seven cross-sectional studies. Mean values and coefficients of variation (CoV) of spatiotemporal gait parameters were recorded during usual walking with the GAITRite® system. The severity of cognitive impairment was associated with worse performance on all gait parameters. Stride velocity had the strongest association with cognitive impairment, regardless of cognitive status. High mean value and CoV of stride length characterized moderate dementia, whereas increased CoV of stride time was specific to MCI status. The findings support the existence of specific cognitive impairment-related gait disturbances with differences related to stages of cognitive impairment, which may be used to screen individuals with cognitive impairment. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

The adaptation of limb kinematics to increasing walking speeds in freely moving mice 129/Sv and C57BL/6.

PubMed

Serradj, Nadjet; Jamon, Marc

2009-07-19

The kinematics of locomotion was analyzed in two strains of great importance for the creation of mutated mice (C56BL/6 and 129/Sv). Different behavioral situations were used to trigger sequences of movement covering the whole range of velocities in the mice, and the variations of kinematic parameters were analyzed in relation with velocity. Both stride frequency and stride length contributed to the moving speed, but stride frequency was found to be the main contributor to the speed increase. A trot-gallop transition was detected at speed about 70 cm/s, in relation with a sharp shift in limb coordination. The results of this study were consistent with pieces of information previously published concerning the gait analyses of other strains, and provided an integrative view of the basic motor pattern of mice. On the other hand some qualitative differences were found in the movement characteristics of the two strains. The stride frequency showed a higher contribution to speed in 129/Sv than in C57BL/6. In addition, 129/Sv showed a phase shift in the forelimb and hindlimb, and a different position of the foot during the stance time that revealed a different gait and body position during walking. Overall, 129/Sv moved at a slower speed than C57BL/6 in any behavioral situation. This difference was related to a basal lower level of motor activity. The possibility that an alteration in the dopamine circuit was responsible for the different movement pattern in 129/Sv is discussed.

Spatial parameters of walking gait and footedness.

PubMed

Zverev, Y P

2006-01-01

The present study was undertaken to assess whether footedness has effects on selected spatial and angular parameters of able-bodied gait by evaluating footprints of young adults. A total of 112 males and 93 females were selected from among students and staff members of the University of Malawi using a simple random sampling method. Footedness of subjects was assessed by the Waterloo Footedness Questionnaire Revised. Gait at natural speed was recorded using the footprint method. The following spatial parameters of gait were derived from the inked footprint sequences of subjects: step and stride lengths, gait angle and base of gait. The anthropometric measurements taken were weight, height, leg and foot length, foot breadth, shoulder width, and hip and waist circumferences. The prevalence of right-, left- and mix-footedness in the whole sample of young Malawian adults was 81%, 8.3% and 10.7%, respectively. One-way analysis of variance did not reveal a statistically significant difference between footedness categories in the mean values of anthropometric measurements (p > 0.05 for all variables). Gender differences in step and stride length values were not statistically significant. Correction of these variables for stature did not change the trend. Males had significantly broader steps than females. Normalized values of base of gait had similar gender difference. The group means of step length and normalized step length of the right and left feet were similar, for males and females. There was a significant side difference in the gait angle in both gender groups of volunteers with higher mean values on the left side compared to the right one (t = 2.64, p < 0.05 for males, and t = 2.78, p < 0.05 for females). One-way analysis of variance did not demonstrate significant difference between footedness categories in the mean values of step length, gait angle, bilateral differences in step length and gait angle, stride length, gait base and normalized gait variables of male and female volunteers (p > 0.05 for all variables). The present study demonstrated that footedness does not affect spatial and angular parameters of walking gait.

The use of body weight support on ground level: an alternative strategy for gait training of individuals with stroke.

PubMed

Sousa, Catarina O; Barela, José A; Prado-Medeiros, Christiane L; Salvini, Tania F; Barela, Ana M F

2009-12-01

Body weight support (BWS) systems on treadmill have been proposed as a strategy for gait training of subjects with stroke. Considering that ground level is the most common locomotion surface and that there is little information about individuals with stroke walking with BWS on ground level, it is important to investigate the use of BWS on ground level in these individuals as a possible alternative strategy for gait training. Thirteen individuals with chronic stroke (four women and nine men; mean age 54.46 years) were videotaped walking on ground level in three experimental conditions: with no harness, with harness bearing full body weight, and with harness bearing 30% of full body weight. Measurements were recorded for mean walking speed, cadence, stride length, stride speed, durations of initial and terminal double stance, single limb support, swing period, and range of motion of ankle, knee, and hip joints; and foot, shank, thigh, and trunk segments. The use of BWS system leads to changes in stride length and speed, but not in stance and swing period duration. Only the hip joint was influenced by the BWS system in the 30% BWS condition. Shank and thigh segments presented less range of motion in the 30% BWS condition than in the other conditions, and the trunk was held straighter in the 30% BWS condition than in the other conditions. Individuals with stroke using BWS system on ground level walked slower and with shorter stride length than with no harness. BWS also led to reduction of hip, shank, and thigh range of motion. However, this system did not change walking temporal organization and body side asymmetry of individuals with stroke. On the other hand, the BWS system enabled individuals with chronic stroke to walk safely and without physical assistance. In interventions, the physical therapist can watch and correct gait pattern in patients' performance without the need to provide physical assistance.

An exploratory clustering approach for extracting stride parameters from tracking collars on free-ranging wild animals.

PubMed

Dewhirst, Oliver P; Roskilly, Kyle; Hubel, Tatjana Y; Jordan, Neil R; Golabek, Krystyna A; McNutt, J Weldon; Wilson, Alan M

2017-02-01

Changes in stride frequency and length with speed are key parameters in animal locomotion research. They are commonly measured in a laboratory on a treadmill or by filming trained captive animals. Here, we show that a clustering approach can be used to extract these variables from data collected by a tracking collar containing a GPS module and tri-axis accelerometers and gyroscopes. The method enables stride parameters to be measured during free-ranging locomotion in natural habitats. As it does not require labelled data, it is particularly suitable for use with difficult to observe animals. The method was tested on large data sets collected from collars on free-ranging lions and African wild dogs and validated using a domestic dog. © 2017. Published by The Company of Biologists Ltd.

Smartphone App-Based Assessment of Gait During Normal and Dual-Task Walking: Demonstration of Validity and Reliability.

PubMed

Manor, Brad; Yu, Wanting; Zhu, Hao; Harrison, Rachel; Lo, On-Yee; Lipsitz, Lewis; Travison, Thomas; Pascual-Leone, Alvaro; Zhou, Junhong

2018-01-30

Walking is a complex cognitive motor task that is commonly completed while performing another task such as talking or making decisions. Gait assessments performed under normal and "dual-task" walking conditions thus provide important insights into health. Such assessments, however, are limited primarily to laboratory-based settings. The objective of our study was to create and test a smartphone-based assessment of normal and dual-task walking for use in nonlaboratory settings. We created an iPhone app that used the phone's motion sensors to record movements during walking under normal conditions and while performing a serial-subtraction dual task, with the phone placed in the user's pants pocket. The app provided the user with multimedia instructions before and during the assessment. Acquired data were automatically uploaded to a cloud-based server for offline analyses. A total of 14 healthy adults completed 2 laboratory visits separated by 1 week. On each visit, they used the app to complete three 45-second trials each of normal and dual-task walking. Kinematic data were collected with the app and a gold-standard-instrumented GAITRite mat. Participants also used the app to complete normal and dual-task walking trials within their homes on 3 separate days. Within laboratory-based trials, GAITRite-derived heel strikes and toe-offs of the phone-side leg aligned with smartphone acceleration extrema, following filtering and rotation to the earth coordinate system. We derived stride times-a clinically meaningful metric of locomotor control-from GAITRite and app data, for all strides occurring over the GAITRite mat. We calculated stride times and the dual-task cost to the average stride time (ie, percentage change from normal to dual-task conditions) from both measurement devices. We calculated similar metrics from home-based app data. For these trials, periods of potential turning were identified via custom-developed algorithms and omitted from stride-time analyses. Across all detected strides in the laboratory, stride times derived from the app and GAITRite mat were highly correlated (P<.001, r 2 =.98). These correlations were independent of walking condition and pocket tightness. App- and GAITRite-derived stride-time dual-task costs were also highly correlated (P<.001, r 2 =.95). The error of app-derived stride times (mean 16.9, SD 9.0 ms) was unaffected by the magnitude of stride time, walking condition, or pocket tightness. For both normal and dual-task trials, average stride times derived from app walking trials demonstrated excellent test-retest reliability within and between both laboratory and home-based assessments (intraclass correlation coefficient range .82-.94). The iPhone app we created enabled valid and reliable assessment of stride timing-with the smartphone in the pocket-during both normal and dual-task walking and within both laboratory and nonlaboratory environments. Additional work is warranted to expand the functionality of this tool to older adults and other patient populations. ©Brad Manor, Wanting Yu, Hao Zhu, Rachel Harrison, On-Yee Lo, Lewis Lipsitz, Thomas Travison, Alvaro Pascual-Leone, Junhong Zhou. Originally published in JMIR Mhealth and Uhealth (http://mhealth.jmir.org), 30.01.2018.

Effects of Continuous and Interval Training on Running Economy, Maximal Aerobic Speed and Gait Kinematics in Recreational Runners.

PubMed

González-Mohíno, Fernando; González-Ravé, José M; Juárez, Daniel; Fernández, Francisco A; Barragán Castellanos, Rubén; Newton, Robert U

2016-04-01

The purpose of this study was to evaluate the effects on running economy (RE), V[Combining Dot Above]O2max, maximal aerobic speed (MAS), and gait kinematics (step length [SL] and frequency, flight and contact time [CT]) in recreational athletes, with 2 different training methods, Interval and Continuous (CON). Eleven participants were randomly distributed in an interval training group (INT; n = 6) or CON training group (CON; n = 5). Interval training and CON performed 2 different training programs (95-110% and 70-75% of MAS, respectively), which consisted of 3 sessions per week during 6 weeks with the same external workload (%MAS × duration). An incremental test to exhaustion was performed to obtain V[Combining Dot Above]O2max, MAS, RE, and gait variables (high speed camera) before and after the training intervention. There was a significant improvement (p ≤ 0.05) in RE at 60 and 90% of MAS by the CON group; without changes in gait. The INT group significantly increased MAS and higher stride length at 80, 90, and 100% of MAS and lower CT at 100% of MAS. As expected, training adaptations are highly specific to the overload applied with CON producing improvements in RE at lower percentage of MAS whereas INT produces improvements in MAS. The significantly increased stride length and decreased CT for the INT group are an important outcome of favorable changes in running gait.

Physiological work performance in chronic low back disability: effects of a progressive activity program.

PubMed

Thomas, L K; Hislop, H J; Waters, R L

1980-04-01

Fifteen patients were tested before and after treatment in a multifaceted inpatient program for chronic low back pain to determine if a gradually progressive activity program affected gait performance and physiological capacity. Before treatment, all patients demonstrated decreased physiological conditioning by higher-than-expected values for oxygen consumption and heart rate and by lower-than-normal gait velocity, stride length, and cadence. After treatment, an increase in mean walking velocity of 19 meters/minute reflected parallel gains in cadence and stride length. Improved mechanical performance resulted in improved "energetics." Energy spent per unit of distance walked decreased by 18 percent after treatment, providing a useful measure of increased physiological efficiency. Results indicated that patients with chronic low back disability can derive significant conditioning effects from an exercise program based on general function.

Gait variability and basal ganglia disorders: stride-to-stride variations of gait cycle timing in Parkinson's disease and Huntington's disease

NASA Technical Reports Server (NTRS)

Hausdorff, J. M.; Cudkowicz, M. E.; Firtion, R.; Wei, J. Y.; Goldberger, A. L.

1998-01-01

The basal ganglia are thought to play an important role in regulating motor programs involved in gait and in the fluidity and sequencing of movement. We postulated that the ability to maintain a steady gait, with low stride-to-stride variability of gait cycle timing and its subphases, would be diminished with both Parkinson's disease (PD) and Huntington's disease (HD). To test this hypothesis, we obtained quantitative measures of stride-to-stride variability of gait cycle timing in subjects with PD (n = 15), HD (n = 20), and disease-free controls (n = 16). All measures of gait variability were significantly increased in PD and HD. In subjects with PD and HD, gait variability measures were two and three times that observed in control subjects, respectively. The degree of gait variability correlated with disease severity. In contrast, gait speed was significantly lower in PD, but not in HD, and average gait cycle duration and the time spent in many subphases of the gait cycle were similar in control subjects, HD subjects, and PD subjects. These findings are consistent with a differential control of gait variability, speed, and average gait cycle timing that may have implications for understanding the role of the basal ganglia in locomotor control and for quantitatively assessing gait in clinical settings.

Influence of custom-made and prefabricated insoles before and after an intense run

PubMed Central

2017-01-01

Each time the foot contacts the ground during running there is a rapid deceleration that results in a shock wave that is transmitted from the foot to the head. The fatigue of the musculoskeletal system during running may decrease the ability of the body to absorb those shock waves and increase the risk of injury. Insoles are commonly prescribed to prevent injuries, and both custom-made and prefabricated insoles have been observed to reduce shock accelerations during running. However, no study to date has included a direct comparison of their behaviour measured over the same group of athletes, and therefore great controversy still exists regarding their effectiveness in reducing impact loading during running. The aim of the study was to analyse the acute differences in stride and shock parameters while running on a treadmill with custom-made and prefabricated insoles. Stride parameters (stride length, stride rate) and shock acceleration parameters (head and tibial peak acceleration, shock magnitude, acceleration rate, and shock attenuation) were measured using two triaxial accelerometers in 38 runners at 3.33 m/s before and after a 15-min intense run while using the sock liner of the shoe (control condition), prefabricated insoles and custom-made insoles. No differences in shock accelerations were found between the custom-made and the control insoles. The prefabricated insoles increased the head acceleration rate (post-fatigue, p = 0.029) compared to the control condition. The custom-made reduced tibial (pre-fatigue, p = 0.041) and head acceleration rates (pre-fatigue and post-fatigue, p = 0.01 and p = 0.046) compared to the prefabricated insoles. Neither the stride nor the acceleration parameters were modified as a result of the intense run. In the present study, the acute use of insoles (custom-made, prefabricated) did not reduce shock accelerations compared to the control insoles. Therefore, their effectiveness at protecting against injuries associated with elevated accelerations is not supported and remains unclear. PMID:28245273

PoleStriding exercise and vitamin E for management of peripheral vascular disease.

PubMed

Collins, Eileen G; Edwin Langbein, W; Orebaugh, Cynthia; Bammert, Christine; Hanson, Karla; Reda, Domenic; Edwards, Lonnie C; Littooy, Fred N

2003-03-01

The purpose of this investigation was to evaluate the efficacy of PoleStriding exercise (a form of walking that uses muscles of the upper and lower body in a continuous movement similar to cross-country skiing) and vitamin E (alpha-tocopherol) to improve walking ability and perceived quality of life (QOL) of patients with claudication pain secondary to peripheral arterial disease (PAD). Fifty-two subjects were randomized into four groups: PoleStriding with vitamin E (N = 13), PoleStriding with placebo (N= 14), vitamin E without exercise (N= 13), and placebo without exercise (N = 12). The dose of vitamin E was 400 IU daily. Only the PoleStriding with vitamin E and PoleStriding with placebo groups received PoleStriding instruction and training. Assignment to vitamin E or placebo was double blind. Subjects trained three times weekly for 30-45 min (rest time excluded). Individuals in vitamin E and placebo groups came to the laboratory biweekly for ankle blood-pressure measurements. Results of this randomized clinical trial provide strong evidence that PoleStriding significantly (P< 0.001) improved exercise tolerance on the constant work-rate and incremental treadmill tests. Ratings of perceived claudication pain were significantly less after the PoleStriding training program (P= 0.02). In contrast, vitamin E did not have a statistically significant effect on the subjects' ratings of perceived leg pain (P= 0.35) or treadmill walking duration ( P= 0.36). Perceived distance and walking speed (Walking Impairment Questionnaire) and perceived physical function (Rand Short Form-36) improved in the PoleStriding trained group only (P< 0.001, 0.022 and 0.003, respectively). PoleStriding effectively improved the exercise tolerance and perceived QOL of patients with PAD. Little additional benefit to exercise capacity was realized from vitamin E supplementation.

Walking in water and on land after an incomplete spinal cord injury.

PubMed

Tamburella, Federica; Scivoletto, Giorgio; Cosentino, Elena; Molinari, Marco

2013-10-01

Although no data are available on the effects of water environment on the gait of subjects with spinal cord injury (SCI), hydrotherapy is used in the rehabilitation protocols of SCI patients. The aim of this study was to characterize gait features of subjects with incomplete SCI walking in water and on land in comparison with healthy controls (CTRLs) to identify the specificity of water environment on influencing gait in SCI subjects. This is a matched case-control study. Kinematic gait parameters and range of motion of joint angles of 15 SCI subjects and 15 CTRLs were analyzed. Compared with gait on land, gait in water of the SCI patients was characterized by speed and stance phase reduction, gait cycle time increment, and invariance of stride length and range of motion values. Comparison with CTRL data remarked that walking in water reduces gait differences between the groups. Furthermore, in water, the SCI subjects presented a reduction in variability of the hip and knee joint angles, whereas in the CTRLs, a larger variability was observed. Gait in water of the SCI subjects is associated with kinematic parameters more similar to those of the CTRLs, particularly regarding speed, stride length, and stance phase, supporting the idea that walking in a water environment may be of rehabilitative significance for SCI subjects.

Scaling of avian bipedal locomotion reveals independent effects of body mass and leg posture on gait.

PubMed

Daley, Monica A; Birn-Jeffery, Aleksandra

2018-05-22

Birds provide an interesting opportunity to study the relationships between body size, limb morphology and bipedal locomotor function. Birds are ecologically diverse and span a large range of body size and limb proportions, yet all use their hindlimbs for bipedal terrestrial locomotion, for at least some part of their life history. Here, we review the scaling of avian striding bipedal gaits to explore how body mass and leg morphology influence walking and running. We collate literature data from 21 species, spanning a 2500× range in body mass from painted quail to ostriches. Using dynamic similarity theory to interpret scaling trends, we find evidence for independent effects of body mass, leg length and leg posture on gait. We find no evidence for scaling of duty factor with body size, suggesting that vertical forces scale with dynamic similarity. However, at dynamically similar speeds, large birds use relatively shorter stride lengths and higher stride frequencies compared with small birds. We also find that birds with long legs for their mass, such as the white stork and red-legged seriema, use longer strides and lower swing frequencies, consistent with the influence of high limb inertia on gait. We discuss the observed scaling of avian bipedal gait in relation to mechanical demands for force, work and power relative to muscle actuator capacity, muscle activation costs related to leg cycling frequency, and considerations of stability and agility. Many opportunities remain for future work to investigate how morphology influences gait dynamics among birds specialized for different habitats and locomotor behaviors. © 2018. Published by The Company of Biologists Ltd.

Accelerometric comparison of the locomotor pattern of horses sedated with xylazine hydrochloride, detomidine hydrochloride, or romifidine hydrochloride.

PubMed

López-Sanromán, F Javier; Holmbak-Petersen, Ronald; Varela, Marta; del Alamo, Ana M; Santiago, Isabel

2013-06-01

To evaluate the duration of effects on movement patterns of horses after sedation with equipotent doses of xylazine hydrochloride, detomidine hydrochloride, or romifidine hydrochloride and determine whether accelerometry can be used to quantify differences among drug treatments. 6 healthy horses. Each horse was injected IV with saline (0.9% NaCl) solution (10 mL), xylazine diluted in saline solution (0.5 mg/kg), detomidine diluted in saline solution (0.01 mg/kg), or romifidine diluted in saline solution (0.04 mg/kg) in random order. A triaxial accelerometric device was used for gait assessment 15 minutes before and 5, 15, 30, 45, 60, 75, 90, 105, and 120 minutes after each treatment. Eight variables were calculated, including speed, stride frequency, stride length, regularity, dorsoventral power, propulsive power, mediolateral power, and total power; the force of acceleration and 3 components of power were then calculated. Significant differences were evident in stride frequency and regularity between treatments with saline solution and each α2-adrenoceptor agonist drug; in speed, dorsoventral power, propulsive power, total power, and force values between treatments with saline solution and detomidine or romifidine; and in mediolateral power between treatments with saline solution and detomidine. Stride length did not differ among treatments. Accelerometric evaluation of horses administered α2-adrenoceptor agonist drugs revealed more prolonged sedative effects of romifidine, compared with effects of xylazine or detomidine. Accelerometry could be useful in assessing the effects of other sedatives and analgesics. Accelerometric data may be helpful in drug selection for situations in which a horse's balance and coordination are important.

Factors Influencing Obstacle Crossing Performance in Patients with Parkinson's Disease

PubMed Central

Liao, Ying-Yi; Yang, Yea-Ru; Wu, Yih-Ru; Wang, Ray-Yau

2014-01-01

Background Tripping over obstacles is the major cause of falls in community-dwelling patients with Parkinson's disease (PD). Understanding the factors associated with the obstacle crossing behavior may help to develop possible training programs for crossing performance. This study aimed to identify the relationships and important factors determining obstacle crossing performance in patients with PD. Methods Forty-two idiopathic patients with PD (Hoehn and Yahr stages I to III) participated in this study. Obstacle crossing performance was recorded by the Liberty system, a three-dimensional motion capture device. Maximal isometric strength of the lower extremity was measured by a handheld dynamometer. Dynamic balance and sensory integration ability were assessed using the Balance Master system. Movement velocity (MV), maximal excursion (ME), and directional control (DC) were obtained during the limits of stability test to quantify dynamic balance. The sum of sensory organization test (SOT) scores was used to quantify sensory organization ability. Results Both crossing stride length and stride velocity correlated significantly with lower extremity muscle strength, dynamic balance control (forward and sideward), and sum of SOT scores. From the regression model, forward DC and ankle dorsiflexor strength were identified as two major determinants for crossing performance (R2 = .37 to.41 for the crossing stride length, R2 = .43 to.44 for the crossing stride velocity). Conclusions Lower extremity muscle strength, dynamic balance control and sensory integration ability significantly influence obstacle crossing performance. We suggest an emphasis on muscle strengthening exercises (especially ankle dorsiflexors), balance training (especially forward DC), and sensory integration training to improve obstacle crossing performance in patients with PD. PMID:24454723

Possible biomechanical origins of the long-range correlations in stride intervals of walking

NASA Astrophysics Data System (ADS)

Gates, Deanna H.; Su, Jimmy L.; Dingwell, Jonathan B.

2007-07-01

When humans walk, the time duration of each stride varies from one stride to the next. These temporal fluctuations exhibit long-range correlations. It has been suggested that these correlations stem from higher nervous system centers in the brain that control gait cycle timing. Existing proposed models of this phenomenon have focused on neurophysiological mechanisms that might give rise to these long-range correlations, and generally ignored potential alternative mechanical explanations. We hypothesized that a simple mechanical system could also generate similar long-range correlations in stride times. We modified a very simple passive dynamic model of bipedal walking to incorporate forward propulsion through an impulsive force applied to the trailing leg at each push-off. Push-off forces were varied from step to step by incorporating both “sensory” and “motor” noise terms that were regulated by a simple proportional feedback controller. We generated 400 simulations of walking, with different combinations of sensory noise, motor noise, and feedback gain. The stride time data from each simulation were analyzed using detrended fluctuation analysis to compute a scaling exponent, α. This exponent quantified how each stride interval was correlated with previous and subsequent stride intervals over different time scales. For different variations of the noise terms and feedback gain, we obtained short-range correlations (α<0.5), uncorrelated time series (α=0.5), long-range correlations (0.5<α<1.0), or Brownian motion (α>1.0). Our results indicate that a simple biomechanical model of walking can generate long-range correlations and thus perhaps these correlations are not a complex result of higher level neuronal control, as has been previously suggested.

Polestriding Intervention Improves Gait and Axial Symptoms in Mild to Moderate Parkinson Disease.

PubMed

Krishnamurthi, Narayanan; Shill, Holly; O'Donnell, Darolyn; Mahant, Padma; Samanta, Johan; Lieberman, Abraham; Abbas, James

2017-04-01

To evaluate the effects of 12-week polestriding intervention on gait and disease severity in people with mild to moderate Parkinson disease (PD). A-B-A withdrawal study design. Outpatient movement disorder center and community facility. Individuals (N=17; 9 women [53%] and 8 men [47%]; mean age, 63.7±4.9y; range, 53-72y) with mild to moderate PD according to United Kingdom brain bank criteria with Hoehn & Yahr score ranging from 2.5 to 3.0 with a stable medication regimen and ability to tolerate "off" medication state. Twelve-week polestriding intervention with 12-week follow-up. Gait was evaluated using several quantitative temporal, spatial, and variability measures. In addition, disease severity was assessed using clinical scales such as Unified Parkinson's Disease Rating Scale (UPDRS), Hoehn & Yahr scale, and Parkinson's Disease Questionnaire-39. Step and stride lengths, gait speed, and step-time variability were improved significantly (P<.05) because of 12-week polestriding intervention. Also, the UPDRS motor score, the UPDRS axial score, and the scores of UPDRS subscales on walking and balance improved significantly after the intervention. Because increased step-time variability and decreased step and stride lengths are associated with PD severity and an increased risk of falls in PD, the observed improvements suggest that regular practice of polestriding may reduce the risk of falls and improve mobility in people with PD. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Smartphone App–Based Assessment of Gait During Normal and Dual-Task Walking: Demonstration of Validity and Reliability

PubMed Central

Yu, Wanting; Zhu, Hao; Harrison, Rachel; Lo, On-Yee; Lipsitz, Lewis; Travison, Thomas; Pascual-Leone, Alvaro; Zhou, Junhong

2018-01-01

Background Walking is a complex cognitive motor task that is commonly completed while performing another task such as talking or making decisions. Gait assessments performed under normal and “dual-task” walking conditions thus provide important insights into health. Such assessments, however, are limited primarily to laboratory-based settings. Objective The objective of our study was to create and test a smartphone-based assessment of normal and dual-task walking for use in nonlaboratory settings. Methods We created an iPhone app that used the phone’s motion sensors to record movements during walking under normal conditions and while performing a serial-subtraction dual task, with the phone placed in the user’s pants pocket. The app provided the user with multimedia instructions before and during the assessment. Acquired data were automatically uploaded to a cloud-based server for offline analyses. A total of 14 healthy adults completed 2 laboratory visits separated by 1 week. On each visit, they used the app to complete three 45-second trials each of normal and dual-task walking. Kinematic data were collected with the app and a gold-standard–instrumented GAITRite mat. Participants also used the app to complete normal and dual-task walking trials within their homes on 3 separate days. Within laboratory-based trials, GAITRite-derived heel strikes and toe-offs of the phone-side leg aligned with smartphone acceleration extrema, following filtering and rotation to the earth coordinate system. We derived stride times—a clinically meaningful metric of locomotor control—from GAITRite and app data, for all strides occurring over the GAITRite mat. We calculated stride times and the dual-task cost to the average stride time (ie, percentage change from normal to dual-task conditions) from both measurement devices. We calculated similar metrics from home-based app data. For these trials, periods of potential turning were identified via custom-developed algorithms and omitted from stride-time analyses. Results Across all detected strides in the laboratory, stride times derived from the app and GAITRite mat were highly correlated (P<.001, r2=.98). These correlations were independent of walking condition and pocket tightness. App- and GAITRite-derived stride-time dual-task costs were also highly correlated (P<.001, r2=.95). The error of app-derived stride times (mean 16.9, SD 9.0 ms) was unaffected by the magnitude of stride time, walking condition, or pocket tightness. For both normal and dual-task trials, average stride times derived from app walking trials demonstrated excellent test-retest reliability within and between both laboratory and home-based assessments (intraclass correlation coefficient range .82-.94). Conclusions The iPhone app we created enabled valid and reliable assessment of stride timing—with the smartphone in the pocket—during both normal and dual-task walking and within both laboratory and nonlaboratory environments. Additional work is warranted to expand the functionality of this tool to older adults and other patient populations. PMID:29382625

Acute effects of anesthetic lumbar spine injections on temporal spatial parameters of gait in individuals with chronic low back pain: A pilot study.

PubMed

Herndon, Carl L; Horodyski, MaryBeth; Vincent, Heather K

2017-10-01

This study examined whether epidural injection-induced anesthesia acutely and positively affected temporal spatial parameters of gait in patients with chronic low back pain (LBP) due to lumbar spinal stenosis. Twenty-five patients (61.7±13.6years) who were obtaining lumbar epidural injections for stenosis-related LBP participated. Oswestry Disability Index (ODI) scores, Medical Outcomes Short Form (SF-36) scores, 11-point Numerical pain rating (NRS pain ) scores, and temporal spatial parameters of walking gait were obtained prior to, and 11-point Numerical pain rating (NRS pain ) scores, and temporal spatial parameters of walking gait were obtained after the injection. Gait parameters were measured using an instrumented gait mat. Patients received transforaminal epidural injections in the L1-S1 vertebral range (1% lidocaine, corticosteroid) under fluoroscopic guidance. Patients with post-injection NRS pain ratings of "0" or values greater than "0" were stratified into two groups: 1) full pain relief, or 2) partial pain relief, respectively. Post-injection, 48% (N=12) of patients reported full pain relief. ODI scores were higher in patients with full pain relief (55.3±21.4 versus 33.7 12.8; p=0.008). Post-injection, stride length and step length variability were significantly improved in the patients with full pain relief compared to those with partial pain relief. Effect sizes between full and partial pain relief for walking velocity, step length, swing time, stride and step length variability were medium to large (Cohen's d>0.50). Patients with LBP can gain immediate gait improvements from complete pain relief from transforaminal epidural anesthetic injections for LBP, which could translate to better stability and lower fall risk. Copyright © 2017 Elsevier B.V. All rights reserved.

Rhythmic auditory stimulation improves gait more than NDT/Bobath training in near-ambulatory patients early poststroke: a single-blind, randomized trial.

PubMed

Thaut, M H; Leins, A K; Rice, R R; Argstatter, H; Kenyon, G P; McIntosh, G C; Bolay, H V; Fetter, M

2007-01-01

The effectiveness of 2 different types of gait training in stroke rehabilitation, rhythmic auditory stimulation (RAS) versus neurodevelopmental therapy (NDT)/Bobath- based training, was compared in 2 groups of hemiparetic stroke patients over a 3-week period of daily training (RAS group, n = 43; NDT/Bobath group =35). Mean entry date into the study was 21.3 days poststroke for the RAS group and 22.3 days for the control group. Patients entered the study as soon as they were able to complete 5 stride cycles with handheld assistance. Patients were closely equated by age, gender, and lesion site. Motor function in both groups was pre-assessed by the Barthel Index and the Fugl-Meyer Scales. Pre- to posttest measures showed a significant improvement in the RAS group for velocity (P = .006), stride length (P = .0001), cadence (P = .0001) and symmetry (P = .0049) over the NDT/Bobath group. Effect sizes for RAS over NDT/Bobath training were 13.1 m/min for velocity, 0.18 m for stride length, and 19 steps/min for cadence. The data show that after 3 weeks of gait training, RAS is an effective therapeutic method to enhance gait training in hemiparetic stroke rehabilitation. Gains were significantly higher for RAS compared to NDT/Bobath training.

Balance and coordination training, but not endurance training, enhances synaptophysin and neurotrophin-3 immunoreactivity in the lumbar spinal cord after sciatic nerve crush.

PubMed

Bonetti, Leandro Viçosa; Ilha, Jocemar; Schneider, Ana Paula Krauthein; Barbosa, Silvia; Faccioni-Heuser, Maria Cristina

2016-04-01

Numerous rehabilitation treatments have been shown to be useful for peripheral and central restoration after (PNI). After sciatic nerve crush, we investigated 4 weeks of endurance training (ET) and balance and coordination training (BCT) with sciatic function index, hind-paw stride length, and spinal cord dorsal horn synaptophysin and neurotrophin-3 immunoreactivity. Our results demonstrated no significant differences between the non-trained (NT), ET, and BCT groups in sciatic functional index, and in stride-length analysis, but the ET showed higher values compared with the NT group. Synaptophysin immunoreactivity was higher in the BCT group compared with the NT group, and neurotrophin-3 immunoreactivity in the BCT group was greater compared with the other groups. BCT can positively affect spinal cord plasticity after a (PNI), and these modifications are important in the rehabilitation process. © 2015 Wiley Periodicals, Inc.

A method for automated control of belt velocity changes with an instrumented treadmill.

PubMed

Hinkel-Lipsker, Jacob W; Hahn, Michael E

2016-01-04

Increased practice difficulty during asymmetrical split-belt treadmill rehabilitation has been shown to improve gait outcomes during retention and transfer tests. However, research in this area has been limited by manual treadmill operation. In the case of variable practice, which requires stride-by-stride changes to treadmill belt velocities, the treadmill control must be automated. This paper presents a method for automation of asymmetrical split-belt treadmill walking, and evaluates how well this method performs with regards to timing of gait events. One participant walked asymmetrically for 100 strides, where the non-dominant limb was driven at their self-selected walking speed, while the other limb was driven randomly on a stride-by-stride basis. In the control loop, the key factors to insure that the treadmill belt had accelerated to its new velocity safely during the swing phase were the sampling rate of the A/D converter, processing time within the controller software, and acceleration of the treadmill belt. The combination of these three factors resulted in a total control loop time during each swing phase that satisfied these requirements with a factor of safety that was greater than 4. Further, a polynomial fit indicated that belt acceleration was the largest contributor to changes in this total time. This approach appears to be safe and reliable for stride-by-stride adjustment of treadmill belt speed, making it suitable for future asymmetrical split-belt walking studies. Further, it can be incorporated into virtual reality rehabilitation paradigms that utilize split-belt treadmill walking. Copyright © 2015 Elsevier Ltd. All rights reserved.

The private life of echidnas: using accelerometry and GPS to examine field biomechanics and assess the ecological impact of a widespread, semi-fossorial monotreme.

PubMed

Clemente, Christofer J; Cooper, Christine E; Withers, Philip C; Freakley, Craig; Singh, Surya; Terrill, Philip

2016-10-15

The short-beaked echidna (Tachyglossus aculeatus) is a monotreme and therefore provides a unique combination of phylogenetic history, morphological differentiation and ecological specialisation for a mammal. The echidna has a unique appendicular skeleton, a highly specialised myrmecophagous lifestyle and a mode of locomotion that is neither typically mammalian nor reptilian, but has aspects of both lineages. We therefore were interested in the interactions of locomotor biomechanics, ecology and movements for wild, free-living short-beaked echidnas. To assess locomotion in its complex natural environment, we attached both GPS and accelerometer loggers to the back of echidnas in both spring and summer. We found that the locomotor biomechanics of echidnas is unique, with lower stride length and stride frequency than reported for similar-sized mammals. Speed modulation is primarily accomplished through changes in stride frequency, with a mean of 1.39 Hz and a maximum of 2.31 Hz. Daily activity period was linked to ambient air temperature, which restricted daytime activity during the hotter summer months. Echidnas had longer activity periods and longer digging bouts in spring compared with summer. In summer, echidnas had higher walking speeds than in spring, perhaps because of the shorter time suitable for activity. Echidnas spent, on average, 12% of their time digging, which indicates their potential to excavate up to 204 m 3 of soil a year. This information highlights the important contribution towards ecosystem health, via bioturbation, of this widespread Australian monotreme. © 2016. Published by The Company of Biologists Ltd.

Physiological and biomechanical responses while running with and without a stroller.

PubMed

Smith, J D; Smith, J D; Kinser, K B; Dugan, E; Reed, M

2005-09-01

This study examined the effects of pushing a jogging stroller on biomechanical and physiological variables. The hypothesis was that running with a stroller for 30 minutes would shorten stride length and increase physiological indices of exercise. this was a repeated measures design. participants were recruited from road races in the Dallas/Fort Worth, TX area. Graded exercise tests were performed in a laboratory setting, field tests were performed on a 400 m all-weather outdoor track. 5 males and 5 females were assessed. participants performed a graded exercise test and 2 field tests. The 1st field test involved running at 75% VO2max for 30 minutes without a stroller and the 2nd involved running at the same speed with the stroller. VO2, stride length, heart rate, lactate, ventilation, and RPE were evaluated. No differences for VO2 or stride length were evident. Heart rate (p=0.0001), lactate concentration (p=0.025), ventilation (p=0.009), and RPE (p=0.002) increased from 10 to 30 minutes while running with the stroller. Heart rate (p=0.002), lactate concentration (p=0.0001), ventilation (p=0.006), and RPE (p=0.001) were significantly higher while running with the stroller after 30 minutes compared to running without it. These results indicate that pushing a stroller affects some indices of exercise intensity while running. Gait does not change. These data do not support an association between stroller use during running and an increase risk of orthopedic injury. Further studies should examine these variables at lower intensities that are run by most recreational joggers.

3D gait assessment in young and elderly subjects using foot-worn inertial sensors.

PubMed

Mariani, Benoit; Hoskovec, Constanze; Rochat, Stephane; Büla, Christophe; Penders, Julien; Aminian, Kamiar

2010-11-16

This study describes the validation of a new wearable system for assessment of 3D spatial parameters of gait. The new method is based on the detection of temporal parameters, coupled to optimized fusion and de-drifted integration of inertial signals. Composed of two wirelesses inertial modules attached on feet, the system provides stride length, stride velocity, foot clearance, and turning angle parameters at each gait cycle, based on the computation of 3D foot kinematics. Accuracy and precision of the proposed system were compared to an optical motion capture system as reference. Its repeatability across measurements (test-retest reliability) was also evaluated. Measurements were performed in 10 young (mean age 26.1±2.8 years) and 10 elderly volunteers (mean age 71.6±4.6 years) who were asked to perform U-shaped and 8-shaped walking trials, and then a 6-min walking test (6MWT). A total of 974 gait cycles were used to compare gait parameters with the reference system. Mean accuracy±precision was 1.5±6.8cm for stride length, 1.4±5.6cm/s for stride velocity, 1.9±2.0cm for foot clearance, and 1.6±6.1° for turning angle. Difference in gait performance was observed between young and elderly volunteers during the 6MWT particularly in foot clearance. The proposed method allows to analyze various aspects of gait, including turns, gait initiation and termination, or inter-cycle variability. The system is lightweight, easy to wear and use, and suitable for clinical application requiring objective evaluation of gait outside of the lab environment. Copyright © 2010 Elsevier Ltd. All rights reserved.

Stride-to-stride variability and complexity between novice and experienced runners during a prolonged run at anaerobic threshold speed.

PubMed

Mo, Shiwei; Chow, Daniel H K

2018-05-19

Motor control, related to running performance and running related injuries, is affected by progression of fatigue during a prolonged run. Distance runners are usually recommended to train at or slightly above anaerobic threshold (AT) speed for improving performance. However, running at AT speed may result in accelerated fatigue. It is not clear how one adapts running gait pattern during a prolonged run at AT speed and if there are differences between runners with different training experience. To compare characteristics of stride-to-stride variability and complexity during a prolonged run at AT speed between novice runners (NR) and experienced runners (ER). Both NR (n = 17) and ER (n = 17) performed a treadmill run for 31 min at his/her AT speed. Stride interval dynamics was obtained throughout the run with the middle 30 min equally divided into six time intervals (denoted as T1, T2, T3, T4, T5 and T6). Mean, coefficient of variation (CV) and scaling exponent alpha of stride intervals were calculated for each interval of each group. This study revealed mean stride interval significantly increased with running time in a non-linear trend (p<0.001). The stride interval variability (CV) maintained relatively constant for NR (p = 0.22) and changed nonlinearly for ER (p = 0.023) throughout the run. Alpha was significantly different between groups at T2, T5 and T6, and nonlinearly changed with running time for both groups with slight differences. These findings provided insights into how the motor control system adapts to progression of fatigue and evidences that long-term training enhances motor control. Although both ER and NR could regulate gait complexity to maintain AT speed throughout the prolonged run, ER also regulated stride interval variability to achieve the goal. Copyright © 2018. Published by Elsevier B.V.

Evaluation of scaling invariance embedded in short time series.

PubMed

Pan, Xue; Hou, Lei; Stephen, Mutua; Yang, Huijie; Zhu, Chenping

2014-01-01

Scaling invariance of time series has been making great contributions in diverse research fields. But how to evaluate scaling exponent from a real-world series is still an open problem. Finite length of time series may induce unacceptable fluctuation and bias to statistical quantities and consequent invalidation of currently used standard methods. In this paper a new concept called correlation-dependent balanced estimation of diffusion entropy is developed to evaluate scale-invariance in very short time series with length ~10(2). Calculations with specified Hurst exponent values of 0.2,0.3,...,0.9 show that by using the standard central moving average de-trending procedure this method can evaluate the scaling exponents for short time series with ignorable bias (≤0.03) and sharp confidential interval (standard deviation ≤0.05). Considering the stride series from ten volunteers along an approximate oval path of a specified length, we observe that though the averages and deviations of scaling exponents are close, their evolutionary behaviors display rich patterns. It has potential use in analyzing physiological signals, detecting early warning signals, and so on. As an emphasis, the our core contribution is that by means of the proposed method one can estimate precisely shannon entropy from limited records.

Evaluation of Scaling Invariance Embedded in Short Time Series

PubMed Central

Pan, Xue; Hou, Lei; Stephen, Mutua; Yang, Huijie; Zhu, Chenping

2014-01-01

Scaling invariance of time series has been making great contributions in diverse research fields. But how to evaluate scaling exponent from a real-world series is still an open problem. Finite length of time series may induce unacceptable fluctuation and bias to statistical quantities and consequent invalidation of currently used standard methods. In this paper a new concept called correlation-dependent balanced estimation of diffusion entropy is developed to evaluate scale-invariance in very short time series with length . Calculations with specified Hurst exponent values of show that by using the standard central moving average de-trending procedure this method can evaluate the scaling exponents for short time series with ignorable bias () and sharp confidential interval (standard deviation ). Considering the stride series from ten volunteers along an approximate oval path of a specified length, we observe that though the averages and deviations of scaling exponents are close, their evolutionary behaviors display rich patterns. It has potential use in analyzing physiological signals, detecting early warning signals, and so on. As an emphasis, the our core contribution is that by means of the proposed method one can estimate precisely shannon entropy from limited records. PMID:25549356

GAIT DYNAMICS, FRACTALS AND FALLS: FINDING MEANING IN THE STRIDE-TO-STRIDE FLUCTUATIONS OF HUMAN WALKING

PubMed Central

Hausdorff, Jeffrey M

2007-01-01

Until recently, quantitative studies of walking have typically focused on properties of a typical or average stride, ignoring the stride-to-stride fluctuations and considering these fluctuations to be noise. Work over the past two decades has demonstrated, however, that the alleged noise actually conveys important information. The magnitude of the stride-to-stride fluctuations and their changes over time during a walk – gait dynamics – may be useful in understanding the physiology of gait, in quantifying age-related and pathologic alterations in the locomotor control system, and in augmenting objective measurement of mobility and functional status Indeed, alterations in gait dynamics may help to determine disease severity, medication utility, and fall risk, and to objectively document improvements in response to therapeutic interventions, above and beyond what can be gleaned from measures based on the average, typical stride. This review discusses support for the idea that gait dynamics has meaning and may be useful in providing insight into the neural control of locomtion and for enhancing functional assessment of aging, chronic disease, and their impact on mobility. PMID:17618701

Is walking a random walk? Evidence for long-range correlations in stride interval of human gait

NASA Technical Reports Server (NTRS)

Hausdorff, Jeffrey M.; Peng, C.-K.; Ladin, Zvi; Wei, Jeanne Y.; Goldberger, Ary L.

1995-01-01

Complex fluctuation of unknown origin appear in the normal gait pattern. These fluctuations might be described as being (1) uncorrelated white noise, (2) short-range correlations, or (3) long-range correlations with power-law scaling. To test these possibilities, the stride interval of 10 healthy young men was measured as they walked for 9 min at their usual rate. From these time series we calculated scaling indexes by using a modified random walk analysis and power spectral analysis. Both indexes indicated the presence of long-range self-similar correlations extending over hundreds of steps; the stride interval at any time depended on the stride interval at remote previous times, and this dependence decayed in a scale-free (fractallike) power-law fashion. These scaling indexes were significantly different from those obtained after random shuffling of the original time series, indicating the importance of the sequential ordering of the stride interval. We demonstrate that conventional models of gait generation fail to reproduce the observed scaling behavior and introduce a new type of central pattern generator model that sucessfully accounts for the experimentally observed long-range correlations.

Gait consistency over a 7-day interval in people with Parkinson's disease.

PubMed

Urquhart, D M; Morris, M E; Iansek, R

1999-06-01

To evaluate the consistency of temporal and spatial parameters of the walking pattern in subjects with idiopathic Parkinson's disease (PD) over a 7-day interval during the "on" phase of the levodopa medication cycle. Walking patterns were measured on a 12-meter walkway at the Kingston Gait Laboratory, Cheltenham, using a computerized stride analyzer. Sixteen subjects (7 women, 9 men) with PD recruited from the Movement Disorders Clinic at Kingston Centre. Speed of walking, stride length, cadence, and the percentage of the walking cycle spent in the double limb support phase of gait were measured, together with the level of disability as indexed by the modified Webster scale. Product-moment correlation coefficients and intraclass correlation coefficients (ICC 2,1) for repeat measures over a 7-day interval were high for speed (r = .90; ICC = .93), cadence (r = .90; ICC = .86), and stride length (r = 1.00; ICC = .97) and moderate for double limb support duration after removal of outliers (r = .75; ICC = .73); 95% confidence intervals for the change scores were within clinically acceptable limits for all variables. The mean modified Webster score was 11.4 on the first day and 10.1 7 days later. The gait pattern and level of disability in subjects with PD without severe motor fluctuations remained stable over a 1-week period when optimal medication prevailed.

Investigating the correlation between paediatric stride interval persistence and gross energy expenditure.

PubMed

Fairley, Jillian A; Sejdić, Ervin; Chau, Tom

2010-02-26

Stride interval persistence, a term used to describe the correlation structure of stride interval time series, is thought to provide insight into neuromotor control, though its exact clinical meaning has not yet been realized. Since human locomotion is shaped by energy efficient movements, it has been hypothesized that stride interval dynamics and energy expenditure may be inherently tied, both having demonstrated similar sensitivities to age, disease, and pace-constrained walking. This study tested for correlations between stride interval persistence and measures of energy expenditure including mass-specific gross oxygen consumption per minute (VO₂), mass-specific gross oxygen cost per meter (VO₂) and heart rate (HR). Metabolic and stride interval data were collected from 30 asymptomatic children who completed one 10-minute walking trial under each of the following conditions: (i) overground walking, (ii) hands-free treadmill walking, and (iii) handrail-supported treadmill walking. Stride interval persistence was not significantly correlated with (p > 0.32), VO₂ (p > 0.18) or HR (p > 0.56). No simple linear dependence exists between stride interval persistence and measures of gross energy expenditure in asymptomatic children when walking overground and on a treadmill.

Quantitative Evaluation of Muscle Function, Gait, and Postural Control in People Experiencing Critical Illness After Discharge From the Intensive Care Unit.

PubMed

Kiriella, Jeevaka B; Araujo, Tamara; Vergara, Martin; Lopez-Hernandez, Laura; Cameron, Jill I; Herridge, Margaret; Gage, William H; Mathur, Sunita

2018-01-01

The path to recovery of muscle strength and mobility following discharge from the intensive care unit (ICU) has not been well described. The study objective was to quantify muscle function, gait, and postural control at 3 and 6 months after discharge in people who were recovering from critical illness and who were ventilated for 7 days or more. This was a nested longitudinal study with continuous inclusion of individuals over a 2-year period and with age- and sex-matched controls. Twenty-four people were tested at 3 months after ICU discharge; 16 of them (67%) were reevaluated at 6 months (post-ICU group). Healthy controls (n = 12) were tested at a single time point. Muscle function of the knee extensors (KEs), plantar flexors (PFs), and dorsiflexors (DFs) was assessed on a dynamometer. Gait was measured using an electronic walkway, and postural control was measured with 2 portable force plates. Muscle weakness was observed across all muscle groups at 3 months, with the greatest strength reductions in the ankle PFs (45%) and DFs (30%). Muscle power was reduced in the PFs and DFs but was not reduced in the KEs. Gait in the post-ICU group was characterized by a narrower step, longer stride, and longer double-support time than in the controls. Improvements were found in KE strength and in stride time and double-support time during gait at 6 months. Leg muscle strength and power had moderate associations with gait velocity, step width, and stride length (r = .44-.65). The small heterogeneous sample of people with a high level of function was a limitation of this study. Muscle strength and power were impaired at 6 months after ICU discharge and were associated with gait parameters. Future studies are needed to examine the role of muscle strength and power training in post-ICU rehabilitation programs to improve mobility. © 2017 American Physical Therapy Association

A gait retraining system using augmented-reality to modify footprint parameters: Effects on lower-limb sagittal-plane kinematics.

PubMed

Bennour, Sami; Ulrich, Baptiste; Legrand, Thomas; Jolles, Brigitte M; Favre, Julien

2018-01-03

Improving lower-limb flexion/extension angles during walking is important for the treatment of numerous pathologies. Currently, these gait retraining procedures are mostly qualitative, often based on visual assessment and oral instructions. This study aimed to propose an alternative method combining motion capture and display of target footprints on the floor. The second objectives were to determine the error in footprint modifications and the effects of footprint modifications on lower-limb flexion/extension angles. An augmented-reality system made of an optoelectronic motion capture device and video projectors displaying target footprints on the floor was designed. 10 young healthy subjects performed a series of 27 trials, consisting of increased and decreased amplitudes in stride length, step width and foot progression angle. 11 standard features were used to describe and compare lower-limb flexion/extension angles among footprint modifications. Subjects became accustomed to walk on target footprints in less than 10 min, with mean (± SD) precision of 0.020 ± 0.002 m in stride length, 0.022 ± 0.006 m in step width, and 2.7 ± 0.6° in progression angle. Modifying stride length had significant effects on 3/3 hip, 2/4 knee and 4/4 ankle features. Similarly, step width and progression angle modifications affected 2/3 and 1/3 hip, 2/4 and 1/4 knee as well as 3/4 and 2/4 ankle features, respectively. In conclusion, this study introduced an augmented-reality method allowing healthy subjects to modify their footprint parameters rapidly and precisely. Walking with modified footprints changed lower-limb sagittal-plane kinematics. Further research is needed to design rehabilitation protocols for specific pathologies. Copyright © 2017 Elsevier Ltd. All rights reserved.

Change in gait after high tibial osteotomy: A systematic review and meta-analysis.

PubMed

Lee, Seung Hoon; Lee, O-Sung; Teo, Seow Hui; Lee, Yong Seuk

2017-09-01

We conducted a meta-analysis to analyze how high tibial osteotomy (HTO) changes gait and focused on the following questions: (1) How does HTO change basic gait variables? (2) How does HTO change the gait variables in the knee joint? Twelve articles were included in the final analysis. A total of 383 knees was evaluated. There were 237 open wedge (OW) and 143 closed wedge (CW) HTOs. There were 4 level II studies and 8 level III studies. All studies included gait analysis and compared pre- and postoperative values. One study compared CWHTO and unicompartmental knee arthroplasty (UKA), and another study compared CWHTO and OWHTO. Five studies compared gait variables with those of healthy controls. One study compared operated limb gait variables with those in the non-operated limb. Gait speed, stride length, knee adduction moment, and lateral thrust were major variables assessed in 2 or more studies. Walking speed increased and stride length was increased or similar after HTO compared to the preoperative value in basic gait variables. Knee adduction moment and lateral thrust were decreased after HTO compared to the preoperative knee joint gait variables. Change in co-contraction of the medial side muscle after surgery differed depending on the degree of frontal plane alignment. The relationship between change in knee adduction moment and change in mechanical axis angle was controversial. Based on our systematic review and meta-analysis, walking speed and stride length increased after HTO. Knee adduction moment and lateral thrust decreased after HTO compared to the preoperative values of gait variables in the knee joint. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparison of the temporal kinematics of the canter pirouette and collected canter.

PubMed

Burns, T E; Clayton, H M

1997-05-01

The objectives were to compare the temporal characteristics of canter pirouette strides with collected canter strides in elite dressage horses, and to determine whether the stride kinematics of the canter pirouettes fulfilled the requirements specified in the Federation Equestre Internationale Rules for Dressage Events. Eleven horses were videotaped (60 fields/s) during the individual medal competition at the 1992 Olympic Games. Temporal variables were extracted from the videotapes using standard methods. Two strides were analysed on each of the left and right leads and these were pooled to give mean values for the collected canter and the pirouettes. The pirouettes were completed in 4-9 strides, (mean of 6.4). In the collected canter strides, mean duration of the suspension was 0.013 s. There was no suspension in any of the pirouette strides, instead the stance phases of the leading forelimb and trailing hindlimb overlapped by a mean of 0.163 s. In 9 horses the trailing forelimb contacted the ground before the diagonal leading hindlimb in the collected canter, whereas in the pirouettes the leading hindlimb always made contact before the trailing forelimb (mean dissociation 0.164 s), giving the strides a distinct 4 beat rhythm. Due to increases in advanced placement between the diagonal limb pair and between the 2 forelimbs, the stride duration was longer in the pirouette (0.879 s) than the collected canter (0.629 s). It is concluded that the canter pirouette strides did not maintain the rhythm and timing of the the collected canter strides in any of the 11 horses.

The effects of core stabilization exercise on dynamic balance and gait function in stroke patients.

PubMed

Chung, Eun-Jung; Kim, Jung-Hee; Lee, Byoung-Hee

2013-07-01

[Purpose] The purpose of this study was to determine the effects of core stabilization exercise on dynamic balance and gait function in stroke patients. [Subjects] The subjects were 16 stroke patients, who were randomly divided into two groups: a core stabilization exercise group of eight subjects and control group of eight subjects. [Methods] Subjects in both groups received general training five times per week. Subjects in the core stabilization exercise group practiced an additional core stabilization exercise program, which was performed for 30 minutes, three times per week, during a period of four weeks. All subjects were evaluated for dynamic balance (Timed Up and Go test, TUG) and gait parameters (velocity, cadence, step length, and stride length). [Results] Following intervention, the core exercise group showed a significant change in TUG, velocity, and cadence. The only significant difference observed between the core group and control group was in velocity. [Conclusion] The results of this study suggest the feasibility and suitability of core stabilization exercise for stroke patients.

Increased gait unsteadiness in community-dwelling elderly fallers

NASA Technical Reports Server (NTRS)

Hausdorff, J. M.; Edelberg, H. K.; Mitchell, S. L.; Goldberger, A. L.; Wei, J. Y.

1997-01-01

OBJECTIVE: To test the hypothesis that quantitative measures of gait unsteadiness are increased in community-dwelling elderly fallers. STUDY DESIGN: Retrospective, case-control study. SETTING: General community. PARTICIPANTS: Thirty-five community-dwelling elderly subjects older than 70 years of age who were capable of ambulating independently for 6 minutes were categorized as fallers (age, 82.2 +/- 4.9 yrs [mean +/- SD]; n = 18) and nonfallers (age, 76.5 +/- 4.0 yrs; n = 17) based on history; 22 young (age, 24.6 +/- 1.9 yrs), healthy subjects also participated as a second reference group. MAIN OUTCOME MEASURES: Stride-to-stride variability (standard deviation and coefficient of variation) of stride time, stance time, swing time, and percent stance time measured during a 6-minute walk. RESULTS: All measures of gait variability were significantly greater in the elderly fallers compared with both the elderly nonfallers and the young subjects (p < .0002). In contrast, walking speed of the elderly fallers was similar to that of the nonfallers. There were little or no differences in the variability measures of the elderly nonfallers compared with the young subjects. CONCLUSIONS: Stride-to-stride temporal variations of gait are relatively unchanged in community-dwelling elderly nonfallers, but are significantly increased in elderly fallers. Quantitative measurement of gait unsteadiness may be useful in assessing fall risk in the elderly.

Acute Effects of Plyometric Intervention—Performance Improvement and Related Changes in Sprinting Gait Variability.

PubMed

Maćkała, Krzysztof; Fostiak, Marek

2015-07-01

The purpose of this study was to examine the effect of a short high-intensity plyometric program on the improvement of explosive power of lower extremities and sprint performance as well as changes in sprinting stride variability in male sprinters. Fourteen healthy male sprinters (mean ± SD: age: 18.07 ± 0.73 years, body mass: 73 ± 9.14 kg, height: 180.57 ± 8.16 cm, and best 100 m: 10.89 ± 0.23) participated in the experiment. The experimental protocol included vertical jumping such as squat jump, countermovement jump, and horizontal jumps; standing long jump and standing triple jumps to assess lower-body power, maximal running velocity; a 20-m flying start sprint that evaluated variability of 10 running steps and 60-m starting block sprint. All analyzed parameters were obtained using the new technology of OptoJump-Microgate (OptoJump, Italy). The short-term plyometric training program significantly increased the explosive power of lower extremities, both vertical and horizontal jumping improvement. However, the vertical jumps increased much more than the horizontal. The 20-m improvements were derived from an increase of stride frequency from 4.31 to 4.39 Hz because of a decrease of ground contact time from 138 to 133 milliseconds. This did not translate into step length changes. Therefore, the significantly increased frequency of stride (1.8%), which is a specific expression of ground contact time reduction during support phase, resulted in an increase of speed. The training volume of 2 weeks (with 6 sessions) using high-intensity (between 180 and 250 jumps per session) plyometric exercises can be recommended as the short-term strategy that will optimize one's probability of reaching strong improvements in explosive power and sprint velocity performance.

Improvements in Dynamic Balance Using an Adaptive Snowboard with the Nintendo Wii.

PubMed

Sullivan, Brendan; Harding, Alexandra G; Dingley, John; Gras, Laura Z

2012-08-01

The purpose of this case report is to see if a novel balance board could improve balance and gait of a subject with dynamic balance impairments and enjoyment of virtual rehabilitation training. A novel Adaptive Snowboard™ (developed by two of the authors, B.S. and J.D.) was used in conjunction with the Nintendo(®) (Redmond, WA) Wii™ snowboarding and wakeboarding games with a participant in a physical therapy outpatient clinic. Baseline measurements were taken for gait velocity and stride length, Four Square Step Test, Star Balance Excursion Test, Sensory Organization Test, and the Intrinsic Motivation Inventory. Two 60-90-minute sessions per week for 5 weeks included seven to nine trials of Wii snowboarding or wakeboarding games. Improvements were seen in every outcome measure. This study had comparable results to studies performed using a wobble board in that improvements in balance were made. Use of virtual snowboard simulation improved the subject's balance, gait speed, and stride length, as well as being an enjoyable activity.

Hip adductor muscle function in forward skating.

PubMed

Chang, Ryan; Turcotte, Rene; Pearsall, David

2009-09-01

Adductor strain injuries are prevalent in ice hockey. It has long been speculated that adductor muscular strains may be caused by repeated eccentric contractions which decelerate the leg during a stride. The purpose of this study was to investigate the relationship of skating speed with muscle activity and lower limb kinematics, with a particular focus on the role of the hip adductors. Seven collegiate ice hockey players consented to participate. Surface electromyography (EMG) and kinematics of the lower extremities were measured at three skating velocities 3.33 m/s (slow), 5.00 m/s (medium) and 6.66 m/s (fast). The adductor magnus muscle exhibited disproportionately larger increases in peak muscle activation and significantly prolonged activation with increased speed. Stride rate and stride length also increased significantly with skating velocity, in contrast, hip, knee and ankle total ranges of motion did not. To accommodate for the increased stride rate with higher skating speeds, the rate of hip abduction increased significantly in concert with activations of adductor magnus indicating a substantial eccentric contraction. In conclusion, these findings highlight the functional importance of the adductor muscle group and hip abduction-adduction in skating performance as well as indirectly support the notion that groin strain injury potential increases with skating speed.

Kinematic Validation of a Multi-Kinect v2 Instrumented 10-Meter Walkway for Quantitative Gait Assessments.

PubMed

Geerse, Daphne J; Coolen, Bert H; Roerdink, Melvyn

2015-01-01

Walking ability is frequently assessed with the 10-meter walking test (10MWT), which may be instrumented with multiple Kinect v2 sensors to complement the typical stopwatch-based time to walk 10 meters with quantitative gait information derived from Kinect's 3D body point's time series. The current study aimed to evaluate a multi-Kinect v2 set-up for quantitative gait assessments during the 10MWT against a gold-standard motion-registration system by determining between-systems agreement for body point's time series, spatiotemporal gait parameters and the time to walk 10 meters. To this end, the 10MWT was conducted at comfortable and maximum walking speed, while 3D full-body kinematics was concurrently recorded with the multi-Kinect v2 set-up and the Optotrak motion-registration system (i.e., the gold standard). Between-systems agreement for body point's time series was assessed with the intraclass correlation coefficient (ICC). Between-systems agreement was similarly determined for the gait parameters' walking speed, cadence, step length, stride length, step width, step time, stride time (all obtained for the intermediate 6 meters) and the time to walk 10 meters, complemented by Bland-Altman's bias and limits of agreement. Body point's time series agreed well between the motion-registration systems, particularly so for body points in motion. For both comfortable and maximum walking speeds, the between-systems agreement for the time to walk 10 meters and all gait parameters except step width was high (ICC ≥ 0.888), with negligible biases and narrow limits of agreement. Hence, body point's time series and gait parameters obtained with a multi-Kinect v2 set-up match well with those derived with a gold standard in 3D measurement accuracy. Future studies are recommended to test the clinical utility of the multi-Kinect v2 set-up to automate 10MWT assessments, thereby complementing the time to walk 10 meters with reliable spatiotemporal gait parameters obtained objectively in a quick, unobtrusive and patient-friendly manner.

Kinematic Validation of a Multi-Kinect v2 Instrumented 10-Meter Walkway for Quantitative Gait Assessments

PubMed Central

Geerse, Daphne J.; Coolen, Bert H.; Roerdink, Melvyn

2015-01-01

Walking ability is frequently assessed with the 10-meter walking test (10MWT), which may be instrumented with multiple Kinect v2 sensors to complement the typical stopwatch-based time to walk 10 meters with quantitative gait information derived from Kinect’s 3D body point’s time series. The current study aimed to evaluate a multi-Kinect v2 set-up for quantitative gait assessments during the 10MWT against a gold-standard motion-registration system by determining between-systems agreement for body point’s time series, spatiotemporal gait parameters and the time to walk 10 meters. To this end, the 10MWT was conducted at comfortable and maximum walking speed, while 3D full-body kinematics was concurrently recorded with the multi-Kinect v2 set-up and the Optotrak motion-registration system (i.e., the gold standard). Between-systems agreement for body point’s time series was assessed with the intraclass correlation coefficient (ICC). Between-systems agreement was similarly determined for the gait parameters’ walking speed, cadence, step length, stride length, step width, step time, stride time (all obtained for the intermediate 6 meters) and the time to walk 10 meters, complemented by Bland-Altman’s bias and limits of agreement. Body point’s time series agreed well between the motion-registration systems, particularly so for body points in motion. For both comfortable and maximum walking speeds, the between-systems agreement for the time to walk 10 meters and all gait parameters except step width was high (ICC ≥ 0.888), with negligible biases and narrow limits of agreement. Hence, body point’s time series and gait parameters obtained with a multi-Kinect v2 set-up match well with those derived with a gold standard in 3D measurement accuracy. Future studies are recommended to test the clinical utility of the multi-Kinect v2 set-up to automate 10MWT assessments, thereby complementing the time to walk 10 meters with reliable spatiotemporal gait parameters obtained objectively in a quick, unobtrusive and patient-friendly manner. PMID:26461498

Biomechanics of Distance Running.

ERIC Educational Resources Information Center

Cavanagh, Peter R., Ed.

Contributions from researchers in the field of running mechanics are included in the 13 chapters of this book. The following topics are covered: (1) "The Mechanics of Distance Running: A Historical Perspective" (Peter Cavanagh); (2) "Stride Length in Distance Running: Velocity, Body Dimensions, and Added Mass Effects" (Peter Cavanagh, Rodger…

Specific smartphone usage and cognitive performance affect gait characteristics during free-living and treadmill walking.

PubMed

Niederer, Daniel; Bumann, Anke; Mühlhauser, Yvonne; Schmitt, Mareike; Wess, Katja; Engeroff, Tobias; Wilke, Jan; Vogt, Lutz; Banzer, Winfried

2018-05-01

Mobile phone tasks like texting, typing, and dialling during walking are known to impact gait characteristics. Beyond that, the effects of performing smartphone-typical actions like researching and taking self-portraits (selfie) on gait have not been investigated yet. We aimed to investigate the effects of smartphone usage on relevant gait characteristics and to reveal potential association of basic cognitive and walking plus smartphone dual-task abilities. Our cross-sectional, cross-over study on physically active, healthy participants was performed on two days, interrupted by a 24-h washout in between. Assessments were: 1) Cognitive testing battery consisting of the trail making test (TMT A and B) and the Stroop test 2) Treadmill walking under five smartphone usage conditions: no use (control condition), reading, dialling, internet searching and taking a selfie in randomized order. Kinematic and kinetic gait characteristics were assessed to estimate conditions influence. In our sample of 36 adults (24.6 ± 1 years, 23 female, 13 male), ANCOVAs followed by post-hoc t-tests revealed that smartphone usage impaired all tested gait characteristics: gait speed (decrease, all conditions): F = 54.7, p < 0.001; cadence (increase, all): F = 38.3, p < 0.001; double stride length (decrease, all): F = 33.8, p < 0.001; foot external rotation (increase during dialling, researching, selfie): F = 16.7, p < 0.001; stride length variability (increase): F = 11.7, p < 0.001; step width variability (increase): F = 5.3, p < 0.001; step width (Friedmann test and Wilcoxon Bonferroni-Holm-corrected post-hoc analyses, increase): Z = -2.3 to -2.9; p < 0.05); plantar pressure proportion (increase during reading and researching) (Z = -2.9; p < 0.01). The ability to keep usual gait quality during smartphone usage was systematically associated with the TMT B time regarding cadence and double stride length for reading (r = -0.37), dialling (r = -0.35) and taking a selfie (r = -0.34). Smartphone usage substantially impacts walking characteristics in most situations. Changes of gait patterns indicate higher cognitive loads and lower awareness. Copyright © 2018 Elsevier B.V. All rights reserved.

Physiological and Biomechanical Considerations for a Human Mars Mission

NASA Astrophysics Data System (ADS)

Hawkey, A.

Evolving on Earth has made humans perfectly adapted, both physiologically and biomechanically, to its gravity and atmospheric conditions. Leaving the Earth and its protective environment, therefore, results in the degradation of a number of human systems. Long-duration stays on the International Space Station (ISS) are accompanied by significant effects on crew's cardiovascular, vestibular and musculoskeletal systems. Bone loss and muscle atrophy are experienced at a rate of 1-3% and 5% per month respectively, while VO2 (oxygen consumption) measurements are reduced by approximately 25% after a few weeks in space. If these figures are simply extrapolated, a future human mission to Mars will be seriously jeopardised and crews may find they cross the threshold of bone and muscle loss and aerobic fitness - ultimately with them being unable to return to Earth. When arriving on Mars, considerable biomechanical alterations will also occur. Optimum walking speeds will be approximately 30% lower and transitioning from a walk to a run will occur at a speed 25% slower. Peak vertical forces will be reduced by as much as 50%, while stride length, stride time and airborne time will all increase. On Mars, half as much energy will be required to travel the equivalent distance on Earth and it will be 65% more economical to run rather than to walk.

A New Paradigm of Technology-Enabled ‘Vital Signs’ for Early Detection of Health Change for Older Adults.

PubMed

Rantz, Marilyn J; Skubic, Marjorie; Popescu, Mihail; Galambos, Colleen; Koopman, Richelle J; Alexander, Gregory L; Phillips, Lorraine J; Musterman, Katy; Back, Jessica; Miller, Steven J

2015-01-01

Environmentally embedded (nonwearable) sensor technology is in continuous use in elder housing to monitor a new set of ‘vital signs' that continuously measure the functional status of older adults, detect potential changes in health or functional status, and alert healthcare providers for early recognition and treatment of those changes. Older adult participants' respiration, pulse, and restlessness are monitored as they sleep. Gait speed, stride length, and stride time are calculated daily, and automatically assess for increasing fall risk. Activity levels are summarized and graphically displayed for easy interpretation. Falls are detected when they occur and alerts are sent immediately to healthcare providers, so time to rescue may be reduced. Automated health alerts are sent to healthcare staff, based on continuously running algorithms applied to the sensor data, days and weeks before typical signs or symptoms are detected by the person, family members, or healthcare providers. Discovering these new functional status ‘vital signs', developing automated methods for interpreting them, and alerting others when changes occur have the potential to transform chronic illness management and facilitate aging in place through the end of life. Key findings of research in progress at the University of Missouri are discussed in this viewpoint article, as well as obstacles to widespread adoption.

Using Plantar Electrical Stimulation to Improve Postural Balance and Plantar Sensation Among Patients With Diabetic Peripheral Neuropathy: A Randomized Double Blinded Study

PubMed Central

Najafi, Bijan; Talal, Talal K.; Grewal, Gurtej Singh; Menzies, Robert; Armstrong, David G.; Lavery, Lawrence A.

2017-01-01

Objective: People with diabetic peripheral neuropathy (DPN) often exhibit deteriorations in motor-performance mainly due to lack of plantar-sensation. The study explored effectiveness of plantar electrical-stimulation therapy to enhance motor-performance among people with DPN. Design and methods: Using a double-blinded model, 28 volunteers with DPN (age: 57.8 ± 10.2 years) were recruited and randomized to either intervention (IG: n = 17) or control (CG: n = 11) group. Both groups received identical plantar-stimulation devices for six weeks of daily use at home; however, only the IG devices were set to deliver stimulation. Balance (ankle, hip, and center of mass [COM] sway) and gait (stride velocity [SV], stride time [ST], stride length [SL], and cadence) were measured using validated wearable sensors. Outcomes were assessed at baseline and at six-week. Clinical assessment including vascular as measured by ankle-brachial-index (ABI) and plantar-sensation as quantified by vibratory plantar threshold (VPT) were also measured at baseline and six weeks. Results: No difference were observed between groups for baseline characteristics (P > .050). Posttherapy, ankle and COM sway with eyes open were significantly improved (P < .05, Cohen’s effect size d = 0.67-0.76) in the IG with no noticeable changes in CG. All gait parameters were significantly improved in the IG with highest effect size observed for cadence (d = 1.35, P = .000). Results revealed improvement in VPT (P = .004, d = 1.15) with significant correlation with stride velocity improvement (r = .56, P = .037). ABI was improved in the IG in particulate among those with ABI>1.20 (P = .041, d = 0.99) Conclusion: This study suggests that daily home use of plantar electrical-stimulation may be a practical means to enhance motor-performance and plantar-sensation in people with DPN. PMID:28627217

Locomotion evaluation for racing in thoroughbreds.

PubMed

Barrey, E; Evans, S E; Evans, D L; Curtis, R A; Quinton, R; Rose, R J

2001-04-01

The potential racing and locomotory profile of a Thoroughbred yearling should be taken into account for its training programme and racing career. A gait test has been designed to assist the trainer in this task. The aim of this study was to investigate the temporal and kinetic locomotory variables of Thoroughbreds at the gallop, in relationship to their racing ability. Thirty Thoroughbred horses in race training were tested at maximal speed during a training session. The training exercise consisted of a warming-up session at trot and canter for 10 min followed by a gallop session at increasing speed on a dirt track 1942 m long. The maximal speed was measured for the last 800 m before the finishing post. An acclerometric device attached to the girth provided quantitative information about the kinetic and temporal variables of the gallop such as: stride length (SL), stride frequency (SF), times elapsed between each hoof midstance phase (HIND, DIAGO, FORE), regularity of the strides (REG), mean vector of propulsion (VPROP), energy of propulsion (EPROP) and energy of loading (ELOAD). The performance records (number of wins, placings and average earning/start [PERF]) were used to analyse the relationship with the gait measurements. The mean maximum speed was 15.26 m/s. Several locomotory variables were significantly (P < 0.05) correlated to the gallop speed: SL (0.90), SF (0.75), DIAGO (0.42), REG (-0.47), VPROP (0.52), ELOAD (0.56) and EPROP (0.65). There were significant correlations between PERF and the following gait variables: REG (0.79), DIAGO (0.43), SF (0.42), SL (-0.32) and ELOAD (-0.40). The horses that won short distance races (< 1400 m) had a larger relative ground contact duration and higher stride frequency than horses that won in longer distance races. The gait test was easy to perform and provided useful locomotory variables that may be used to evaluate the racing ability of the Thoroughbreds in training.

Effects of form-focused training on running biomechanics: A pilot randomized trial in untrained individuals

PubMed Central

Kumar, Deepak; McDermott, Kelly; Feng, Haojun; Goldman, Veronica; Luke, Anthony; Souza, Richard B; Hecht, Frederick M

2015-01-01

Objective To investigate the changes in running biomechanics after training in Form-Focused running using ChiRunning vs. Not-Form focused training and Self-Directed training in untrained individuals. Design Pilot study - Randomized controlled trial. Setting Research Institution with Tertiary Care Medical Center. Participants Seventeen subjects (9 males, 8 females) with pre-hypertension. Methods Twenty-two participants were randomized to three study arms but 17 completed the study. The study arms were: 1) group-based Form-Focused running using ChiRunning (enrolled, n =10; completed, n=7); 2) group-based conventional running (enrolled, n=6; completed, n=4); 3) self-directed training with educational materials (enrolled, n =6; completed, n=6). The training schedule was prescribed for 8 weeks with 4 weeks of follow-up. All subjects completed overground running motion analyses before and after training. Outcomes Ankle, knee, hip joint peak moments and powers; Average vertical loading rate (AVLR), impact peak, cadence, stride length, strike index, and stride reach. Paired T-tests were used to compare differences with-in groups over-time. Results Form-Focused group reduced their Stride Reach (P = .047) after the training but not the other groups. Form-Focused group showed a close to significant reduction in knee adduction moment (P = .051) and a reduction in the peak ankle eversion moment (P = .027). Self-Directed group showed an increase in the running speed, (P =.056) and increases in ankle and knee joint powers and moments. Conclusions There are differences in the changes in running biomechanics between individuals trained in running form that emphazies mid-foot strike, higher cadence, and shorter stride compared to those not trained in the thise technique. These differences may be associated with reduced lower extremity stress in individuals trained in this running form but future studies are needed to confirm these findings in larger samples. PMID:25633634

Immediate Effects of Mental Singing While Walking on Gait Disturbance in Hemiplegic Stroke Patients: A Feasibility Study

PubMed Central

2018-01-01

Objective To investigate the immediate therapeutic effects of mental singing while walking intervention on gait disturbances in hemiplegic stroke patients. Methods Eligible, post-stroke, hemiplegic patients were prospectively enrolled in this study. The inclusion criteria were a diagnosis of hemiplegia due to stroke, and ability to walk more than 10 m with or without gait aids. Each patient underwent structured music therapy sessions comprising 7 consecutive tasks, and were trained to sing in their mind (mental singing) while walking. Before, and after training sessions, gait ability was assessed using the 10-Meter Walk Test (10MWT), the Timed Up and Go test (TUG), gait velocity, cadence and stride length. Results Twenty patients were enrolled in the interventions. Following the mental singing while walking intervention, significant improvement was observed in the 10MWT (13.16±7.61 to 12.27±7.58; p=0.002) and the TUG test (19.36±15.37 to 18.42±16.43; p=0.006). Significant improvement was also seen in gait cadence (90.36±29.11 to 95.36±30.2; p<0.001), stride length (90.99±33.4 to 98.17±35.33; p<0.001) and velocity (0.66±0.45 to 0.71±0.47; p<0.002). Conclusion These results indicate the possible effects of mental singing while walking on gait in patients diagnosed with hemiplegic stroke. PMID:29560318

The feasibility of singing to improve gait in Parkinson disease

PubMed Central

Harrison, Elinor C.; McNeely, Marie E.; Earhart, Gammon M.

2017-01-01

Brain regions important for controlling movement are also responsible for rhythmic processing. In Parkinson disease (PD), defective internal timing within the brain has been linked to impaired beat discrimination, and may contribute to a loss of ability to maintain a steady gait rhythm. Less rhythmic gait is inherently less efficient, and this may lead to gait impairment including reduced speed, cadence, and stride length, as well as increased variability. While external rhythmic auditory stimulation (e.g. a metronome beat) is well-established as an effective tool to stabilize gait in PD, little is known about whether self-generated cues such as singing have the same beneficial effect on gait in PD. Thus, we compared gait patterns of 23 people with mild to moderate PD under five cued conditions: uncued, music only, singing only, singing with music, and a verbal dual-task condition. In our single session study, singing while walking did not significantly alter velocity, cadence, or stride length, indicating that it was not excessively demanding for people with PD. In addition, walking was less variable when singing than during other cued conditions. This was further supported by the comparison between singing trials and a verbal dual-task condition. In contrast to singing, the verbal dual-task negatively affected gait performance. These findings suggest that singing holds promise as an effective cueing technique that may be as good as or better than traditional cueing techniques for improving gait among people with PD. PMID:28226309

The feasibility of singing to improve gait in Parkinson disease.

PubMed

Harrison, Elinor C; McNeely, Marie E; Earhart, Gammon M

2017-03-01

Brain regions important for controlling movement are also responsible for rhythmic processing. In Parkinson disease (PD), defective internal timing within the brain has been linked to impaired beat discrimination, and may contribute to a loss of ability to maintain a steady gait rhythm. Less rhythmic gait is inherently less efficient, and this may lead to gait impairment including reduced speed, cadence, and stride length, as well as increased variability. While external rhythmic auditory stimulation (e.g. a metronome beat) is well-established as an effective tool to stabilize gait in PD, little is known about whether self-generated cues such as singing have the same beneficial effect on gait in PD. Thus, we compared gait patterns of 23 people with mild to moderate PD under five cued conditions: uncued, music only, singing only, singing with music, and a verbal dual-task condition. In our single-session study, singing while walking did not significantly alter velocity, cadence, or stride length, indicating that it was not excessively demanding for people with PD. In addition, walking was less variable when singing than during other cued conditions. This was further supported by the comparison between singing trials and a verbal dual-task condition. In contrast to singing, the verbal dual-task negatively affected gait performance. These findings suggest that singing holds promise as an effective cueing technique that may be as good as or better than traditional cueing techniques for improving gait among people with PD. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of Two Years of Exercise on Gait Impairment in People with Parkinson’s Disease: The PRET-PD Randomized Trial

PubMed Central

Rafferty, Miriam R.; Prodoehl, Janey; Robichaud, Julie A.; David, Fabian J.; Poon, Cynthia; Goelz, Lisa C.; Vaillancourt, David E.; Kohrt, Wendy M.; Comella, Cynthia L.; Corcos, Daniel M.

2016-01-01

Background and Purpose This study presents a secondary analysis from the Progressive Resistance Exercise Training in Parkinson disease (PRET-PD) trial investigating the effects of progressive resistance exercise (PRE) and a PD-specific multimodal exercise program, modified Fitness Counts (mFC), on spatial, temporal, and stability-related gait impairments in people with Parkinson disease (PD). Methods Forty-eight people with PD were randomized to participate in PRE or mFC 2×/week for 24 months; 38 completed the study. Gait velocity, stride length, cadence, and double support time were measured under 4 walking conditions (off/on medication, comfortable/fast speed). Ankle strength was also measured off and on medication. Twenty-four healthy controls provided comparison data at one time point. Results At 24 months, there were no significant differences between exercise groups. Both groups improved fast gait velocity off medication, cadence in all conditions, and plantarflexion strength off/on medication. Both groups with PD had more gait measures that approximated the heathy controls at 24 months than at baseline. Plantarflexion strength was significantly associated with gait velocity and stride length in people with PD at baseline and 24 months, but changes in strength were not associated with changes in gait. Discussion and Conclusions Twenty-four months of PRE and mFC were associated with improved off medication fast gait velocity and improved cadence in all conditions, which is important because temporal gait measures can be resistant to medications. Spatial and stability-related measures were resistant to long-term improvements, but did not decline over 24 months. Strength gains did not appear to transfer to gait. Video Abstract available for more insights from the authors (see Supplemental Digital Content 1). PMID:27977518

Therapeutic horse riding improves cognition, mood arousal, and ambulation in children with dyspraxia.

PubMed

Hession, Caren E; Eastwood, Brian; Watterson, David; Lehane, Christine M; Oxley, Nigel; Murphy, Barbara A

2014-01-01

The objectives of this study were to evaluate the effects of the physical motion of a horse (riding therapy) combined with the audiovisual perception of this motion on a group of children with dyspraxia in terms of cognition, mood arousal, and gait variability. The study design was a pretest/post-test. The study was conducted at the Fettercairn Youth Horse Project, Fettercairn, Tallaght, Dublin. Forty (40) children ranging from 6 to 15 years of age with a primary diagnosis of dyspraxia were the study subjects. Children meeting inclusion criteria participated in six 30-minute horse-riding sessions and two 30-minute audiovisual screening sessions. A Standard Progressive Matrices test (also known as the Ravens test) was used to measure aspects of general intelligence. A Childhood Depression Inventory (CDI) questionnaire was used to assess cognitive, affective, and behavioral signs of depression. A GAITRite Pressure Mapping System analyzed foot function and gait variability by measuring single and double support, cycle time, cadence, toe in/out, and stride length. Significant improvements were evident on the Ravens test and the CDI by the end of the study period. The amount of both single and double support required while completing the walking task also was significantly reduced. Improvements were visible on toe in/out values, cycle time, and cadence. Changes in stride length did not reach statistical significance. These findings support the theory that riding therapy and/or the perception of beat-based rhythms, as experienced by the rider on the horse, stimulates cognition, mood, and gait parameters. In addition, the data also pointed to the potential value of an audiovisual approach to equine therapy.

Defining small differences in efficacy between anti-parkinsonian agents using gait analysis: a comparison of two controlled release formulations of levodopa/decarboxylase inhibitor.

PubMed Central

Weller, C; O'Neill, C J; Charlett, A; Bowes, S G; Purkiss, A; Nicholson, P W; Dobbs, R J; Dobbs, S M

1993-01-01

1. Stride length is highly relevant to mobility and is sensitive to the effects of levodopa in Parkinsonism. Its selection as the primary outcome criterion allowed comparison of two levodopa/decarboxylase inhibitor formulations using a small number of subjects. 2. It is also desirable to improve stability. An instrumental method, based on infrared telemetry, has been developed which obtains both distance/time measures of gait and broadness of base, as measured by foot separation at mid-swing. The latter was used as a subsidiary outcome criterion. 3. Nine patients (aged 57 to 77 years) then receiving maintenance therapy for idiopathic Parkinsonism with Sinemet CR alone, but who had previously experienced end of dose effect within 4 h of receiving a dose of a conventional formulation of levodopa/decarboxylase inhibitor, were studied. 4. They received, in random order and at least 4 days apart, single doses of one tablet of Sinemet CR (200 mg levodopa/50 mg carbidopa) and of two capsules of Madopar CR (each 100 mg levodopa/25 mg benserazide), with placebo balance, at 10.00 h. Gait analysis was carried out immediately before and half-hourly for 7 h after a challenge. No routine doses of Sinemet CR were taken between 22.00 h on the night before and 17.00 h on the day of a challenge. 5. Analysis of variance showed a highly significant difference in mean stride length (P < 0.001) and in mean foot separation (P = 0.01) between serial time points, irrespective of the nature of treatment. There appeared to be a useful therapeutic response to both challenges.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8485018

Surface Peroneal Nerve Stimulation in Lower Limb Hemiparesis: Effect on Quantitative Gait Parameters

PubMed Central

Sheffler, Lynne R.; Taylor, Paul N.; Bailey, Stephanie Nogan; Gunzler, Douglas D.; Buurke, Jaap H.; IJzerman, Maarten J.; Chae, John

2015-01-01

Objective To evaluate possible mechanisms for functional improvement and compare ambulation training with surface peroneal nerve stimulation (PNS) versus usual care (UC) via quantitative gait analysis. Design Randomized controlled clinical trial. Setting Teaching hospital of academic medical center. Participants 110 chronic stroke survivors (> 12-wks post-stroke) with unilateral hemiparesis. Interventions Subjects were randomized to a surface PNS device or UC intervention. Subjects were treated for 12-wks and followed for 6-months post-treatment. Main Outcome Measures Spatiotemporal, kinematic, and kinetic parameters of gait. Results Cadence (F3,153=5.81, p=.012), stride length (F3,179=20.01, p<.001), walking speed (F3,167=18.2, p<.001), anterior posterior ground reaction force (F3,164=6.61, p=.004), peak hip power in pre-swing (F3,156=8.76, p<.001), and peak ankle power at push-off (F3,149=6.38, p=.005) all improved with respect to time. However, peak ankle DF in swing (F3,184=4.99, p=.031) worsened. In general, the greatest change for all parameters occurred during the treatment period. There was no significant treatment group by time interaction effects for any of the spatiotemporal, kinematic, or kinetic parameters. Conclusions Gait training with PNS and usual care was associated with improvements in peak hip power in pre-swing and peak ankle power at push-off, which may have resulted in improved cadence, stride length, and walking speed; however, there were no differences between treatment groups. Both treatment groups also experienced a decrease in peak ankle DF in swing, though the clinical implications of this finding are unclear. PMID:25802966

Effects of high doses of oxytetracycline on metacarpophalangeal joint kinematics in neonatal foals.

PubMed

Kasper, C A; Clayton, H M; Wright, A K; Skuba, E V; Petrie, L

1995-07-01

Thirteen clinically normal Belgian-type foals were used to study the effects of high doses of oxytetracycline on metacarpophalangeal joint kinematics. Seven foals (treatment group) received 2 doses of oxytetracycline (3 g, IV). The first dose was given when foals were 4 days old; the second dose was given 24 hours later. Six foals (control group) received 2 doses of saline (0.9% NaCl) solution (15 ml, IV) at equivalent time periods. All foals were videotaped at a walk twice: immediately prior to the first treatment and 24 hours after the second treatment. The tapes were digitized, and metacarpophalangeal joint angle was measured along the palmar surface of the limb during 3 strides. The angular data were normalized for time, and data from the 3 strides were averaged to describe a representative stride. Repeated measures ANOVA was used to test for differences between groups and within groups over time. Values for stride duration, stance phase percentage, and minimum metacarpophalangeal joint angle obtained before treatment were not significantly different from values obtained after treatment. Maximum metacarpophalangeal joint angle, which occurred during the stance phase of the stride, and range of joint motion were significantly increased for foals in the treatment group, compared with foals in the control group.

Walking on an Oscillating Treadmill: Two Paths to Functional Adaptation

NASA Technical Reports Server (NTRS)

Brady, Rachel A.; Peters, Brian T.; Bloomberg, Jacob J.

2010-01-01

We mounted a treadmill on top of a six degree-of-freedom motion base platform to investigate and characterize locomotor responses produced by healthy adults when introduced to a novel walking condition. Subjects were classified into two groups according to how their stride times were affected by the perturbation. Our data suggest that a person's choice of adaptation strategy is influenced by the relationship between his unique, natural stride frequency and the external frequency imposed by the motion base. Our data suggest that a person's stride time response while walking on a laterally oscillating treadmill is influenced by the relationship between his unique, natural stride frequency and the imposed external frequency of the motion base. This relationship may be useful for checking the efficacy of gait training and rehabilitation programs. Preselecting and manipulating a person's EST could be one way to draw him out of his preferred "entrainment well" during therapy or training.

Association between stride time fractality and gait adaptability during unperturbed and asymmetric walking.

PubMed

Ducharme, Scott W; Liddy, Joshua J; Haddad, Jeffrey M; Busa, Michael A; Claxton, Laura J; van Emmerik, Richard E A

2018-04-01

Human locomotion is an inherently complex activity that requires the coordination and control of neurophysiological and biomechanical degrees of freedom across various spatiotemporal scales. Locomotor patterns must constantly be altered in the face of changing environmental or task demands, such as heterogeneous terrains or obstacles. Variability in stride times occurring at short time scales (e.g., 5-10 strides) is statistically correlated to larger fluctuations occurring over longer time scales (e.g., 50-100 strides). This relationship, known as fractal dynamics, is thought to represent the adaptive capacity of the locomotor system. However, this has not been tested empirically. Thus, the purpose of this study was to determine if stride time fractality during steady state walking associated with the ability of individuals to adapt their gait patterns when locomotor speed and symmetry are altered. Fifteen healthy adults walked on a split-belt treadmill at preferred speed, half of preferred speed, and with one leg at preferred speed and the other at half speed (2:1 ratio asymmetric walking). The asymmetric belt speed condition induced gait asymmetries that required adaptation of locomotor patterns. The slow speed manipulation was chosen in order to determine the impact of gait speed on stride time fractal dynamics. Detrended fluctuation analysis was used to quantify the correlation structure, i.e., fractality, of stride times. Cross-correlation analysis was used to measure the deviation from intended anti-phasing between legs as a measure of gait adaptation. Results revealed no association between unperturbed walking fractal dynamics and gait adaptability performance. However, there was a quadratic relationship between perturbed, asymmetric walking fractal dynamics and adaptive performance during split-belt walking, whereby individuals who exhibited fractal scaling exponents that deviated from 1/f performed the poorest. Compared to steady state preferred walking speed, fractal dynamics increased closer to 1/f when participants were exposed to asymmetric walking. These findings suggest there may not be a relationship between unperturbed preferred or slow speed walking fractal dynamics and gait adaptability. However, the emergent relationship between asymmetric walking fractal dynamics and limb phase adaptation may represent a functional reorganization of the locomotor system (i.e., improved interactivity between degrees of freedom within the system) to be better suited to attenuate externally generated perturbations at various spatiotemporal scales. Copyright © 2018 Elsevier B.V. All rights reserved.

When Human Walking is a Random Walk

NASA Astrophysics Data System (ADS)

Hausdorff, J. M.

1998-03-01

The complex, hierarchical locomotor system normally does a remarkable job of controlling an inherently unstable, multi-joint system. Nevertheless, the stride interval --- the duration of a gait cycle --- fluctuates from one stride to the next, even under stationary conditions. We used random walk analysis to study the dynamical properties of these fluctuations under normal conditions and how they change with disease and aging. Random walk analysis of the stride-to-stride fluctuations of healthy, young adult men surprisingly reveals a self-similar pattern: fluctuations at one time scale are statistically similar to those at multiple other time scales (Hausdorff et al, J Appl Phsyiol, 1995). To study the stability of this fractal property, we analyzed data obtained from healthy subjects who walked for 1 hour at their usual pace, as well as at slower and faster speeds. The stride interval fluctuations exhibited long-range correlations with power-law decay for up to a thousand strides at all three walking rates. In contrast, during metronomically-paced walking, these long-range correlations disappeared; variations in the stride interval were uncorrelated and non-fractal (Hausdorff et al, J Appl Phsyiol, 1996). To gain insight into the mechanism(s) responsible for this fractal property, we examined the effects of aging and neurological impairment. Using detrended fluctuation analysis (DFA), we computed α, a measure of the degree to which one stride interval is correlated with previous and subsequent intervals over different time scales. α was significantly lower in healthy elderly subjects compared to young adults (p < .003) and in subjects with Huntington's disease, a neuro-degenerative disorder of the central nervous system, compared to disease-free controls (p < 0.005) (Hausdorff et al, J Appl Phsyiol, 1997). α was also significantly related to degree of functional impairment in subjects with Huntington's disease (r=0.78). Recently, we have observed that just as there are changes with α during aging, there also changes with development. Apparently, the fractal scaling of walking does not become mature until children are eleven years old. Conclusions: The fractal dynamics of spontaneous stride interval fluctuations are normally quite robust and are apparently intrinsic to the healthy adult locomotor system. However, alterations in this fractal scaling property are associated with impairment in central nervous system control, aging and neural development.

Relationships between body composition, body dimensions, and peak speed in cross-country sprint skiing.

PubMed

Stoggl, Thomas; Enqvist, Jonas; Muller, Erich; Holmberg, Hans-Christer

2010-01-01

In modern sprint cross-country skiing, strength and maximal speed are major determinants of performance. The aims of this study were to ascertain the anthropometric characteristics of world-class sprint skiers and to evaluate whether a specific body composition and/or body dimension characterizes a successful sprint skier. Our hypothesis was that body height and lean body mass are related to peak speed in double poling and diagonal stride. Fourteen male national and international elite skiers performed two peak speed tests in double poling and diagonal stride roller skiing on a treadmill and were analysed using dual-energy X-ray absorptiometry to determine body composition and body dimensions. Relative pole length was positively correlated with both techniques (double poling: r = 0.77, P < 0.01; diagonal stride: r = 0.60, P < 0.05) and was the only variable that was part of the multiple regression model for both double poling and diagonal stride peak speed. Body height was not correlated with any technique, whereas lean trunk mass (r = 0.75, P < 0.01), body mass index (r = 0.66, P < 0.01), total lean mass (r = 0.69, P < 0.01), and body mass (r = 0.57, P < 0.05) were positively related to double poling peak speed. Total lean mass (absolute: r = 0.58, P < 0.05; relative: r = 0.76, P < 0.001) and relative lean mass of the trunk, arms (both r = 0.72, P < 0.01), and legs (r = 0.54, P < 0.05) were positively related to diagonal stride peak speed. In conclusion, skiers should aim to achieve a body composition with a high percentage of lean mass and low fat mass. A focus on trunk mass through increased muscle mass appears to be important, especially for double poling. The use of longer poles (percent body height) seems to be advantageous for both double poling and diagonal stride peak speed, whereas body dimensions do not appear to be a predictive factor.

Stride search: A general algorithm for storm detection in high-resolution climate data

DOE PAGES

Bosler, Peter A.; Roesler, Erika L.; Taylor, Mark A.; ...

2016-04-13

This study discusses the problem of identifying extreme climate events such as intense storms within large climate data sets. The basic storm detection algorithm is reviewed, which splits the problem into two parts: a spatial search followed by a temporal correlation problem. Two specific implementations of the spatial search algorithm are compared: the commonly used grid point search algorithm is reviewed, and a new algorithm called Stride Search is introduced. The Stride Search algorithm is defined independently of the spatial discretization associated with a particular data set. Results from the two algorithms are compared for the application of tropical cyclonemore » detection, and shown to produce similar results for the same set of storm identification criteria. Differences between the two algorithms arise for some storms due to their different definition of search regions in physical space. The physical space associated with each Stride Search region is constant, regardless of data resolution or latitude, and Stride Search is therefore capable of searching all regions of the globe in the same manner. Stride Search's ability to search high latitudes is demonstrated for the case of polar low detection. Wall clock time required for Stride Search is shown to be smaller than a grid point search of the same data, and the relative speed up associated with Stride Search increases as resolution increases.« less

Three-dimensional kinematics of the lower limbs during forward ice hockey skating.

PubMed

Upjohn, Tegan; Turcotte, René; Pearsall, David J; Loh, Jonathan

2008-05-01

The objectives of the study were to describe lower limb kinematics in three dimensions during the forward skating stride in hockey players and to contrast skating techniques between low- and high-calibre skaters. Participant motions were recorded with four synchronized digital video cameras while wearing reflective marker triads on the thighs, shanks, and skates. Participants skated on a specialized treadmill with a polyethylene slat bed at a self-selected speed for 1 min. Each participant completed three 1-min skating trials separated by 5 min of rest. Joint and limb segment angles were calculated within the local (anatomical) and global reference planes. Similar gross movement patterns and stride rates were observed; however, high-calibre participants showed a greater range and rate of joint motion in both the sagittal and frontal planes, contributing to greater stride length for high-calibre players. Furthermore, consequent postural differences led to greater lateral excursion during the power stroke in high-calibre skaters. In conclusion, specific kinematic differences in both joint and limb segment angle movement patterns were observed between low- and high-calibre skaters.

The Effects of Walking Workstations on Biomechanical Performance.

PubMed

Grindle, Daniel M; Baker, Lauren; Furr, Mike; Puterio, Tim; Knarr, Brian; Higginson, Jill

2018-04-03

Prolonged sitting has been associated with negative health effects. Walking workstations have become increasingly popular in the workplace. There is a lack of research on the biomechanical effect of walking workstations. This study analyzed whether walking while working alters normal gait patterns. Nine participants completed four walking trials at 2.4 km·h -1 and 4.0 km·h -1 : baseline walking condition, walking while performing a math task, a reading task, and a typing task. Biomechanical data were collected using standard motion capture procedures. The first maximum vertical ground reaction force, stride width, stride length, minimum toe clearance, peak swing hip abduction and flexion angles, peak swing and stance ankle dorsiflexion and knee flexion angles were analyzed. Differences between conditions were evaluated using analysis of variance tests with Bonferroni correction (p ≤ 0.05). Stride width decreased during the reading task at both speeds. Although other parameters exhibited significant differences when multitasking, these changes were within the normal range of gait variability. It appears that for short periods, walking workstations do not negatively impact gait in healthy young adults.

Reference data for normal subjects obtained with an accelerometric device.

PubMed

Auvinet, Bernard; Berrut, Gilles; Touzard, Claude; Moutel, Laurent; Collet, Nadine; Chaleil, Denis; Barrey, Eric

2002-10-01

We collected gait analysis data for 282 healthy adults and elderly people (144 women and 138 men aged 20-98) using an accelerometric device, whose reproducibility (intra-tester and inter-testers) has been validated for gait studies. The subjects walked at their own speed along a corridor (40 m). Stride frequency (SF) (after correction for height), step symmetry (Sym), stride regularity (Reg), and vertical harmonic (slope) were all independent of age or gender. The median-lateral harmonic (slope) (MSH) was influenced by gender, but not by age. Other variables (walking speed, stride length (SL), cranial-caudal activity and raw accelerations at heel contact, mid-stance and initial push-off) were dependent on gender and age. They were higher in men than in women, and began to decrease during the sixth decade in men and the seventh decade in women. The raw acceleration at foot flat was independent of gender but was influenced by age. This accelerometric device is easy to use and requires no specialized equipment and could be used to analyze walking in clinical practice.

Gait analysis in demented subjects: Interests and perspectives

PubMed Central

Beauchet, Olivier; Allali, Gilles; Berrut, Gilles; Hommet, Caroline; Dubost, Véronique; Assal, Frédéric

2008-01-01

Gait disorders are more prevalent in dementia than in normal aging and are related to the severity of cognitive decline. Dementia-related gait changes (DRGC) mainly include decrease in walking speed provoked by a decrease in stride length and an increase in support phase. More recently, dual-task related changes in gait were found in Alzheimer’s disease (AD) and non-Alzheimer dementia, even at an early stage. An increase in stride-to-stride variability while usual walking and dual-tasking has been shown to be more specific and sensitive than any change in mean value in subjects with dementia. Those data show that DRGC are not only associated to motor disorders but also to problem with central processing of information and highlight that dysfunction of temporal and frontal lobe may in part explain gait impairment among demented subjects. Gait assessment, and more particularly dual-task analysis, is therefore crucial in early diagnosis of dementia and/or related syndromes in the elderly. Moreover, dual-task disturbances could be a specific marker of falling at a pre-dementia stage. PMID:18728766

Fractal fluctuations in spatiotemporal variables when walking on a self-paced treadmill.

PubMed

Choi, Jin-Seung; Kang, Dong-Won; Seo, Jeong-Woo; Tack, Gye-Rae

2017-12-08

This study investigated the fractal dynamic properties of stride time (ST), stride length (SL) and stride speed (SS) during walking on a self-paced treadmill (STM) in which the belt speed is automatically controlled by the walking speed. Twelve healthy young subjects participated in the study. The subjects walked at their preferred walking speed under four conditions: STM, STM with a metronome (STM+met), fixed-speed (conventional) treadmill (FTM), and FTM with a metronome (FTM+met). To compare the fractal dynamics between conditions, the mean, variability, and fractal dynamics of ST, SL, and SS were compared. Moreover, the relationship among the variables was examined under each walking condition using three types of surrogates. The mean values of all variables did not differ between the two treadmills, and the variability of all variables was generally larger for STM than for FTM. The use of a metronome resulted in a decrease in variability in ST and SS for all conditions. The fractal dynamic characteristics of SS were maintained with STM, in contrast to FTM, and only the fractal dynamic characteristics of ST disappeared when using a metronome. In addition, the fractal dynamic patterns of the cross-correlated surrogate results were identical to those of all variables for the two treadmills. In terms of the fractal dynamic properties, STM walking was generally closer to overground walking than FTM walking. Although further research is needed, the present results will be useful in research on gait fractal dynamics and rehabilitation. Copyright © 2017 Elsevier Ltd. All rights reserved.

High speed galloping in the cheetah (Acinonyx jubatus) and the racing greyhound (Canis familiaris): spatio-temporal and kinetic characteristics.

PubMed

Hudson, Penny E; Corr, Sandra A; Wilson, Alan M

2012-07-15

The cheetah and racing greyhound are of a similar size and gross morphology and yet the cheetah is able to achieve a far higher top speed. We compared the kinematics and kinetics of galloping in the cheetah and greyhound to investigate how the cheetah can attain such remarkable maximum speeds. This also presented an opportunity to investigate some of the potential limits to maximum running speed in quadrupeds, which remain poorly understood. By combining force plate and high speed video data of galloping cheetahs and greyhounds, we show how the cheetah uses a lower stride frequency/longer stride length than the greyhound at any given speed. In some trials, the cheetahs used swing times as low as those of the greyhounds (0.2 s) so the cheetah has scope to use higher stride frequencies (up to 4.0 Hz), which may contribute to it having a higher top speed that the greyhound. Weight distribution between the animal's limbs varied with increasing speed. At high speed, the hindlimbs support the majority of the animal's body weight, with the cheetah supporting 70% of its body weight on its hindlimbs at 18 m s(-1); however, the greyhound hindlimbs support just 62% of its body weight. Supporting a greater proportion of body weight on a particular limb is likely to reduce the risk of slipping during propulsive efforts. Our results demonstrate several features of galloping and highlight differences between the cheetah and greyhound that may account for the cheetah's faster maximum speeds.

Biomechanical and physiological comparison of barefoot and two shod conditions in experienced barefoot runners.

PubMed

Squadrone, R; Gallozzi, C

2009-03-01

The first aim of this study was to assess how changes in the mechanical characteristics of the foot/shoe-ground interface affect spatio-temporal variables, ground pressure distribution, sagittal plane kinematics, and running economy in 8 experienced barefoot runners. The second aim was to assess if a special lightweight shoe (Vibram Fivefingers) was effective in mimic the experience of barefoot running. By using an instrumented treadmill, barefoot running, running with the Fivefingers, and running with standard running shoe were compared, analyzing a large numbers of consecutive steps. Foot/shoe-ground interface pressure distribution, lower limb kinematics, V.O(2) and heart rate data were simultaneously collected. Compared to the standard shod condition when running barefoot the athletes landed in more plantarflexion at the ankle. This caused reduced impact forces and changes in stride kinematics. In particular, significantly shorter stride length and contact times and higher stride frequency were observed (P<0.05). Compared to standard shod condition, V.O(2) and peak impact forces were significantly lower with Fivefingers (P<0.05) and much closer to barefoot running. Lower limb kinematics with Fivefingers was similar to barefoot running with a foot position which was significantly more plantarflexed than in control shoe (P<0.05). The data of this study support the assumption that changes in the foot-ground interface led to changes in running pattern in a group of experienced barefoot runners. The Fivefingers model seems to be effective in imitating the barefoot conditions while providing a small amount of protection.

Effect of trotting speed on kinematic variables measured by use of extremity-mounted inertial measurement units in nonlame horses performing controlled treadmill exercise.

PubMed

Cruz, Antonio M; Vidondo, Beatriz; Ramseyer, Alessandra A; Maninchedda, Ugo E

2018-02-01

OBJECTIVE To assess effects of speed on kinematic variables measured by use of extremity-mounted inertial measurement units (IMUs) in nonlame horses performing controlled exercise on a treadmill. ANIMALS 10 nonlame horses. PROCEDURES 6 IMUs were attached at predetermined locations on 10 nonlame Franches Montagnes horses. Data were collected in triplicate during trotting at 3.33 and 3.88 m/s on a high-speed treadmill. Thirty-three selected kinematic variables were analyzed. Repeated-measures ANOVA was used to assess the effect of speed. RESULTS Significant differences between the 2 speeds were detected for most temporal (11/14) and spatial (12/19) variables. The observed spatial and temporal changes would translate into a gait for the higher speed characterized by increased stride length, protraction and retraction, flexion and extension, mediolateral movement of the tibia, and symmetry, but with similar temporal variables and a reduction in stride duration. However, even though the tibia coronal range of motion was significantly different between speeds, the high degree of variability raised concerns about whether these changes were clinically relevant. For some variables, the lower trotting speed apparently was associated with more variability than was the higher trotting speed. CONCLUSIONS AND CLINICAL RELEVANCE At a higher trotting speed, horses moved in the same manner (eg, the temporal events investigated occurred at the same relative time within the stride). However, from a spatial perspective, horses moved with greater action of the segments evaluated. The detected changes in kinematic variables indicated that trotting speed should be controlled or kept constant during gait evaluation.

Dribbling determinants in sub-elite youth soccer players.

PubMed

Zago, Matteo; Piovan, Andrea Gianluca; Annoni, Isabella; Ciprandi, Daniela; Iaia, F Marcello; Sforza, Chiarella

2016-01-01

Dribbling speed in soccer is considered critical to the outcome of the game and can assist in the talent identification process. However, little is known about the biomechanics of this skill. By means of a motion capture system, we aimed to quantitatively investigate the determinants of effective dribbling skill in a group of 10 Under-13 sub-elite players, divided by the median-split technique according to their dribbling test time (faster and slower groups). Foot-ball contacts cadence, centre of mass (CoM), ranges of motion (RoM), velocity and acceleration, as well as stride length, cadence and variability were computed. Hip and knee joint RoMs were also considered. Faster players, as compared to slower players, showed a 30% higher foot-ball cadence (3.0 ± 0.1 vs. 2.3 ± 0.2 contacts · s(-1), P < 0.01); reduced CoM mediolateral (0.91 ± 0.05 vs. 1.14 ± 0.16 m, P < 0.05) and vertical (0.19 ± 0.01 vs. 0.25 ± 0.03 m, P < 0.05) RoMs; higher right stride cadence (+20%, P < 0.05) with lower variability (P < 0.05); reduced hip and knee flexion RoMs (P < 0.05). In conclusion, faster players are able to run with the ball through a shorter path in a more economical way. To effectively develop dribbling skill, coaches are encouraged to design specific practices where high stride frequency and narrow run trajectories are required.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bosler, Peter A.; Roesler, Erika L.; Taylor, Mark A.

This study discusses the problem of identifying extreme climate events such as intense storms within large climate data sets. The basic storm detection algorithm is reviewed, which splits the problem into two parts: a spatial search followed by a temporal correlation problem. Two specific implementations of the spatial search algorithm are compared: the commonly used grid point search algorithm is reviewed, and a new algorithm called Stride Search is introduced. The Stride Search algorithm is defined independently of the spatial discretization associated with a particular data set. Results from the two algorithms are compared for the application of tropical cyclonemore » detection, and shown to produce similar results for the same set of storm identification criteria. Differences between the two algorithms arise for some storms due to their different definition of search regions in physical space. The physical space associated with each Stride Search region is constant, regardless of data resolution or latitude, and Stride Search is therefore capable of searching all regions of the globe in the same manner. Stride Search's ability to search high latitudes is demonstrated for the case of polar low detection. Wall clock time required for Stride Search is shown to be smaller than a grid point search of the same data, and the relative speed up associated with Stride Search increases as resolution increases.« less

Stroller running: Energetic and kinematic changes across pushing methods.

PubMed

Alcantara, Ryan S; Wall-Scheffler, Cara M

2017-01-01

Running with a stroller provides an opportunity for parents to exercise near their child and counteract health declines experienced during early parenthood. Understanding biomechanical and physiological changes that occur when stroller running is needed to evaluate its health impact, yet the effects of stroller running have not been clearly presented. Here, three commonly used stroller pushing methods were investigated to detect potential changes in energetic cost and lower-limb kinematics. Sixteen individuals (M/F: 10/6) ran at self-selected speeds for 800m under three stroller conditions (2-Hands, 1-Hand, and Push/Chase) and an independent running control. A significant decrease in speed (p = 0.001) and stride length (p<0.001) was observed between the control and stroller conditions, however no significant change in energetic cost (p = 0.080) or heart rate (p = 0.393) was observed. Additionally, pushing method had a significant effect on speed (p = 0.001) and stride length (p<0.001). These findings suggest that pushing technique influences stroller running speed and kinematics. These findings suggest specific fitness effects may be achieved through the implementation of different pushing methods.

Spatial-temporal parameters of gait in women with fibromyalgia.

PubMed

Heredia Jiménez, José María; Aparicio García-Molina, Virginia A; Porres Foulquie, Jesús M; Delgado Fernández, Manuel; Soto Hermoso, Victor M

2009-05-01

The aim of the present study was to determine if there are differences in such parameters among patients affected by fibromyalgia (FM) and healthy subjects and whether the degree of affectation by FM can decrease the gait parameters. We studied 55 women with FM and 44 controls. Gait analysis was performed using an instrumented walkway for measurement of the kinematic parameters of gait (GAITRite system), and patients completed a Spanish version of Fibromyalgia Impact Questionnaire (FIQ). Significant differences (p < 0.001) between FM and control groups were found in velocity, stride length, cadence, single support ratio, double support ratio, stance phase ratio, and swing phase ratio. There were significant inverse correlations between FIQ and velocity, stride length, swing phase, and single support, whereas significant direct correlations were found with stance phase and double support. Gait parameters of women affected by FM were severely impaired when compared to those of healthy women. Different factors such as lack of physical activity, bradikinesia, overweight, fatigue, and pain together with a lower isometric force in the legs can be responsible for the alterations in gait and poorer life quality of women with FM.

Locomotion of inchworm-inspired robot made of smart soft composite (SSC).

PubMed

Wang, Wei; Lee, Jang-Yeob; Rodrigue, Hugo; Song, Sung-Hyuk; Chu, Won-Shik; Ahn, Sung-Hoon

2014-10-07

A soft-bodied robot made of smart soft composite with inchworm-inspired locomotion capable of both two-way linear and turning movement has been proposed, developed, and tested. The robot was divided into three functional parts based on the different functions of the inchworm: the body, the back foot, and the front foot. Shape memory alloy wires were embedded longitudinally in a soft polymer to imitate the longitudinal muscle fibers that control the abdominal contractions of the inchworm during locomotion. Each foot of the robot has three segments with different friction coefficients to implement the anchor and sliding movement. Then, utilizing actuation patterns between the body and feet based on the looping gait, the robot achieves a biomimetic inchworm gait. Experiments were conducted to evaluate the robot's locomotive performance for both linear locomotion and turning movement. Results show that the proposed robot's stride length was nearly one third of its body length, with a maximum linear speed of 3.6 mm s(-1), a linear locomotion efficiency of 96.4%, a maximum turning capability of 4.3 degrees per stride, and a turning locomotion efficiency of 39.7%.

Locomotion energetics and gait characteristics of a rat-kangaroo, Bettongia penicillata, have some kangaroo-like features.

PubMed

Webster, K N; Dawson, T J

2003-09-01

The locomotory characteristics of kangaroos and wallabies are unusual, with both energetic costs and gait parameters differing from those of quadrupedal running mammals. The kangaroos and wallabies have an evolutionary history of only around 5 million years; their closest relatives, the rat-kangaroos, have a fossil record of more than 26 million years. We examined the locomotory characteristics of a rat-kangaroo, Bettongia penicillata. Locomotory energetics and gait parameters were obtained from animals exercising on a motorised treadmill at speeds from 0.6 m s(-1) to 6.2 m s(-1). Aerobic metabolic costs increased as hopping speed increased, but were significantly different from the costs for a running quadruped; at the fastest speed, the cost of hopping was 50% of the cost of running. Therefore B. penicillata can travel much faster than quadrupedal runners at similar levels of aerobic output. The maximum aerobic output of B. penicillata was 17 times its basal metabolism. Increases in speed during hopping were achieved through increases in stride length, with stride frequency remaining constant. We suggest that these unusual locomotory characteristics are a conservative feature among the hopping marsupials, with an evolutionary history of 20-30 million years.

Comparison of 2 Different Exercise Approaches: Tai Chi Versus Otago, in Community-Dwelling Older Women.

PubMed

Son, Nam-Kuk; Ryu, Young Uk; Jeong, Hye-Won; Jang, Young-Hwan; Kim, Hyeong-Dong

2016-01-01

Regular exercise can delay age-related risk factors and can maintain or improve physical health and activity in older adults leading to a decrease in fall risk. The purpose of this study was to compare 2 different interventions for fall prevention, tai chi (TC) and Otago, by examining lower extremity strength, balance, and spatiotemporal gait parameters in community-dwelling older women. We performed a randomized trial in which subjects were assigned to 1 of 2 groups: the TC group (n = 21; age, 72.8 ± 4.7 years, range: 65-83 years), which participated in a modified Sun-style TC exercise program; and the Otago group (n = 24; age, 71.5 ± 3.6 years, range: 65-79 years), which participated in the Otago exercise program. The Timed Up and Go (TUG) test, functional reach (FR) test, one-leg standing (OLS) test, 5 times sit-to-stand test (5×STS), 30-second sit-to-stand (30s STS) test, and gait parameters (gait velocity, step length, step width, stride time, and cadence) were measured before and after the intervention. Both groups showed statistically significant improvements in balance (TUG and OLS tests), lower extremity strength (5×STS and 30s STS tests), and spatiotemporal gait parameters, except for step width and step length (P < .05). The Otago group showed a significantly improved FR, whereas the TC group showed a significantly improved step length after the intervention (P < .05). Furthermore, the Otago group exhibited greater improvements in the TUG (P < .001), FR (P < .001), 5×CST (P < .01), and 30-second CST (P < .01) tests: a faster cadence (P < .001) and shorter stride time (P < .001) when compared with the TC group. The TC group showed greater improvements in the OLS test, step length, and step width (P < .01) and faster gait velocity (P < .05) than the Otago group. The findings from this study support the efficacy of the TC and Otago exercise programs in improving mobility in this sample of subjects. Furthermore, the Otago group showed greater improvement in lower extremity strength, whereas the TC group showed greater improvement in balance (OLS test). Also, the TC group showed a greater improvement in gait velocity after TC training program compared with the Otago exercise program. However, this study does not elucidate which exercise program is a more effective intervention method with older women for fall prevention.

Changes in the limb kinematics and walking-distance estimation after shank elongation: evidence for a locomotor body schema?

PubMed

Dominici, Nadia; Daprati, Elena; Nico, Daniele; Cappellini, Germana; Ivanenko, Yuri P; Lacquaniti, Francesco

2009-03-01

When walking, step length provides critical information on traveled distance along the ongoing path [corrected] Little is known on the role that knowledge about body dimensions plays within this process. Here we directly addressed this question by evaluating whether changes in body proportions interfere with computation of traveled distance for targets located outside the reaching space. We studied locomotion and distance estimation in an achondroplastic child (ACH, 11 yr) before and after surgical elongation of the shank segments of both lower limbs and in healthy adults walking on stilts, designed to mimic shank-segment elongation. Kinematic analysis of gait revealed that dynamic coupling of the thigh, shank, and foot segments changed substantially as a result of elongation. Step length remained unvaried, in spite of the significant increase in total limb length ( approximately 1.5-fold). These relatively shorter strides resulted from smaller oscillations of the shank segment, as would be predicted by proportional increments in limb size and not by asymmetrical segmental increment as in the present case (length of thighs was not modified). Distance estimation was measured by walking with eyes closed toward a memorized target. Before surgery, the behavior of ACH was comparable to that of typically developing participants. In contrast, following shank elongation, the ACH walked significantly shorter distances when aiming at the same targets. Comparable changes in limb kinematics, stride length, and estimation of traveled distance were found in adults wearing on stilts, suggesting that path integration errors in both cases were related to alterations in the intersegmental coordination of the walking limbs. The results are consistent with a dynamic locomotor body schema used for controlling step length and path estimation, based on inherent relationships between gait parameters and body proportions.

[Effects of training on static and dynamic balance in elderly subjects who have had a fall or not].

PubMed

Toulotte, C; Thévenon, A; Fabre, C

2004-11-01

To evaluate the effects of a physical training program on static and dynamic balance during single and dual task conditions in elderly subjects who have had a fall or not. Two groups, comprising a total of 33 elderly subjects, were trained: 16 who had a fall were 69.2 +/- 5.0 years old and 17 who had not had a fall were 67.3 +/- 3.8 years. All subjects underwent an unipedal test with eyes open and eyes closed, followed by gait assessment during single and dual motor task conditions, before and after a physical training program. All subjects showed a significant decrease, by six times for subjects who had fallen and four times by those who had not, in the number of touch-downs in the unipedal test with eyes open (P < 0.05), and by 2.5 and 2 times, respectively, with eyes closed (P < 0.05) after the training program. All subjects showed a significant increase in speed (P < 0.05), cadence (P < 0.05) and stride length (P < 0.05) and a significant decrease in the single support time (P < 0.05) and stride time (P < 0.05) in gait assessment during single and dual task conditions after the training program. During the training program, no subjects fell. The physical training program improved static balance and quality of gait in elderly subjects who had had a fall and those who had not, which could contribute to minimizing and/or retarding the effects of aging and maintaining physical independence.

Clinical usefulness of augmented reality using infrared camera based real-time feedback on gait function in cerebral palsy: a case study.

PubMed

Lee, Byoung-Hee

2016-04-01

[Purpose] This study investigated the effects of real-time feedback using infrared camera recognition technology-based augmented reality in gait training for children with cerebral palsy. [Subjects] Two subjects with cerebral palsy were recruited. [Methods] In this study, augmented reality based real-time feedback training was conducted for the subjects in two 30-minute sessions per week for four weeks. Spatiotemporal gait parameters were used to measure the effect of augmented reality-based real-time feedback training. [Results] Velocity, cadence, bilateral step and stride length, and functional ambulation improved after the intervention in both cases. [Conclusion] Although additional follow-up studies of the augmented reality based real-time feedback training are required, the results of this study demonstrate that it improved the gait ability of two children with cerebral palsy. These findings suggest a variety of applications of conservative therapeutic methods which require future clinical trials.

Reliability and comparison of Kinect-based methods for estimating spatiotemporal gait parameters of healthy and post-stroke individuals.

PubMed

Latorre, Jorge; Llorens, Roberto; Colomer, Carolina; Alcañiz, Mariano

2018-04-27

Different studies have analyzed the potential of the off-the-shelf Microsoft Kinect, in its different versions, to estimate spatiotemporal gait parameters as a portable markerless low-cost alternative to laboratory grade systems. However, variability in populations, measures, and methodologies prevents accurate comparison of the results. The objective of this study was to determine and compare the reliability of the existing Kinect-based methods to estimate spatiotemporal gait parameters in healthy and post-stroke adults. Forty-five healthy individuals and thirty-eight stroke survivors participated in this study. Participants walked five meters at a comfortable speed and their spatiotemporal gait parameters were estimated from the data retrieved by a Kinect v2, using the most common methods in the literature, and by visual inspection of the videotaped performance. Errors between both estimations were computed. For both healthy and post-stroke participants, highest accuracy was obtained when using the speed of the ankles to estimate gait speed (3.6-5.5 cm/s), stride length (2.5-5.5 cm), and stride time (about 45 ms), and when using the distance between the sacrum and the ankles and toes to estimate double support time (about 65 ms) and swing time (60-90 ms). Although the accuracy of these methods is limited, these measures could occasionally complement traditional tools. Copyright © 2018 Elsevier Ltd. All rights reserved.

The effects of additional arm weights on arm-swing magnitude and gait patterns in Parkinson's disease.

PubMed

Yoon, Jiyeon; Park, Jinse; Park, Kunbo; Jo, Geunyeol; Kim, Haeyu; Jang, Wooyoung; Kim, Ji Sun; Youn, Jinyoung; Oh, Eung Seok; Kim, Hee-Tae; Youm, Chang Hong

2016-01-01

Recently, arm facilitation has been interested in gait rehabilitation. However, there have been few studies concerning arm facilitation in patients with Parkinson's disease (PD). The aim of our study was to investigate the effect of increasing arm weights on gait pattern in patients with PD. Twenty-seven patients with PD were enrolled, and they underwent gait analysis using a three-dimensional motion capture system. Sandbags were applied to the distal forearms in all participants. We compared gait parameters including arm swing, pelvic motion, spatiotemporal data, and relative rotational angle between the weighted and unweighted gaits. The total arm-swing amplitude and pelvic rotation were significantly higher when walking with additional arm weights than without arm weights. Cadence, walking speed, stride length, and swing phase were significantly higher, whereas stride time, double-support time, and stance phase were significantly lower, when walking with additional arm weights than without arm weights. We conclude that adding weights to the arm during walking may facilitate arm and pelvic movements, which results in changes to gait patterns. The therapeutic use of additional arm weights could be considered for gait rehabilitation in PD to improve gait impairment. Arm-swing facilitation using weight load improved gait in Parkinson's disease. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Shedding light on walking in the dark: the effects of reduced lighting on the gait of older adults with a higher-level gait disorder and controls.

PubMed

Kesler, Anat; Leibovich, Gregory; Herman, Talia; Gruendlinger, Leor; Giladi, Nir; Hausdorff, Jeffrey M

2005-08-28

To study the effects of reduced lighting on the gait of older adults with a high level gait disorder (HLGD) and to compare their response to that of healthy elderly controls. 22 patients with a HLGD and 20 age-matched healthy controls were studied under usual lighting conditions (1000 lumens) and in near darkness (5 lumens). Gait speed and gait dynamics were measured under both conditions. Cognitive function, co-morbidities, depressive symptoms, and vision were also evaluated. Under usual lighting conditions, patients walked more slowly, with reduced swing times, and increased stride-to-stride variability, compared to controls. When walking under near darkness conditions, both groups slowed their gait. All other measures of gait were not affected by lighting in the controls. In contrast, patients further reduced their swing times and increased their stride-to-stride variability, both stride time variability and swing time variability. The unique response of the patients was not explained by vision, mental status, co-morbidities, or the values of walking under usual lighting conditions. Walking with reduced lighting does not affect the gait of healthy elderly subjects, except for a reduction in speed. On the other hand, the gait of older adults with a HLGD becomes more variable and unsteady when they walk in near darkness, despite adapting a slow and cautious gait. Further work is needed to identify the causes of the maladaptive response among patients with a HLGD and the potential connection between this behavior and the increased fall risk observed in these patients.

Development of Independent Locomotion in Children with a Severe Visual Impairment

ERIC Educational Resources Information Center

Hallemans, Ann; Ortibus, Els; Truijen, Steven; Meire, Francoise

2011-01-01

Locomotion of children and adults with a visual impairment (ages 1-44, n = 28) was compared to that of age-related individuals with normal vision (n = 60). Participants walked barefoot at preferred speed while their gait was recorded by a Vicon[R] system. Walking speed, heading angle, step frequency, stride length, step width, stance phase…

Apolipoprotein E4 Allele and Gait Performance in Mild Cognitive Impairment: Results From the Gait and Brain Study.

PubMed

Sakurai, Ryota; Montero-Odasso, Manuel

2017-11-09

The apolipoprotein E polymorphism ε4 allele (ApoE4) and gait impairment are both known risk factors for developing cognitive decline and dementia. However, it is unclear the interrelationship between these factors, particularly among older adults with mild cognitive impairment (MCI) who are considered as prodromal for Alzheimer's disease. This study aimed to determine whether ApoE4 carrier individuals with MCI may experience greater impairment in gait performance. Fifty-six older adults with MCI from the "Gait and Brain Study" who were identified as either ApoE4 carriers (n = 20) or non-ApoE4 carriers (n = 36) with 1 year of follow-up were included. Gait variability, the main outcome variable, was assessed as stride time variability with an electronic walkway. Additional gait variables and cognitive performance (mini-mental state examination [MMSE] and Montreal Cognitive Assessment [MoCA]) were also recorded. Covariates included age, sex, education level, body mass index, and number of comorbidities. Baseline characteristics were similar for both groups. Repeated measures analysis of covariance showed that gait stride time and stride length variabilities significantly increased in ApoE4 carriers but was maintained in the non-ApoE4 carriers. Similarly, ApoE4 carriers showed greater decrease in MMSE score at follow-up. In this sample of older adults with MCI, the presence of at least one copy of ApoE4 was associated with the development of both increased gait variability and cognitive decline during 1 year of follow-up. ApoE4 genotype might be considered as a potential mediator of decline in mobility function in MCI; future studies with larger samples are needed to confirm our preliminary findings. © The Author 2017. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Ambulatory estimation of foot placement during walking using inertial sensors.

PubMed

Martin Schepers, H; van Asseldonk, Edwin H F; Baten, Chris T M; Veltink, Peter H

2010-12-01

This study proposes a method to assess foot placement during walking using an ambulatory measurement system consisting of orthopaedic sandals equipped with force/moment sensors and inertial sensors (accelerometers and gyroscopes). Two parameters, lateral foot placement (LFP) and stride length (SL), were estimated for each foot separately during walking with eyes open (EO), and with eyes closed (EC) to analyze if the ambulatory system was able to discriminate between different walking conditions. For validation, the ambulatory measurement system was compared to a reference optical position measurement system (Optotrak). LFP and SL were obtained by integration of inertial sensor signals. To reduce the drift caused by integration, LFP and SL were defined with respect to an average walking path using a predefined number of strides. By varying this number of strides, it was shown that LFP and SL could be best estimated using three consecutive strides. LFP and SL estimated from the instrumented shoe signals and with the reference system showed good correspondence as indicated by the RMS difference between both measurement systems being 6.5 ± 1.0 mm (mean ± standard deviation) for LFP, and 34.1 ± 2.7 mm for SL. Additionally, a statistical analysis revealed that the ambulatory system was able to discriminate between the EO and EC condition, like the reference system. It is concluded that the ambulatory measurement system was able to reliably estimate foot placement during walking. Copyright © 2010 Elsevier Ltd. All rights reserved.

Outcome of orthoses intervention in the rheumatoid foot.

PubMed

Kavlak, Yasemin; Uygur, Fatma; Korkmaz, Cengiz; Bek, Nilgün

2003-06-01

This study was carried out to determine the effect of foot orthoses on pain, gait, and energy expenditure in patients with rheumatoid arthritis. Eighteen patients were evaluated for these parameters. Each patient was given a foot insert or shoe modification suitable for his or her foot deformity. Following 3 months of orthosis use, a significant difference was found in regards to pain (p < .05), step length and stride length (p < .05), and physiological cost index (p < .05). The results suggest that foot orthoses are an important feature in the rehabilitation of the rheumatoid foot.

The effects of mirror therapy on the gait of subacute stroke patients: a randomized controlled trial.

PubMed

Ji, Sang Gu; Kim, Myoung Kwon

2015-04-01

To investigate the effect of mirror therapy on the gait of patients with subacute stroke. Randomized controlled experimental study. Outpatient rehabilitation hospital. Thirty-four patients with stroke were randomly assigned to two groups: a mirror therapy group (experimental) and a control group. The stroke patients in the experimental group underwent comprehensive rehabilitation therapy and mirror therapy for the lower limbs. The stroke patients in the control group underwent sham therapy and comprehensive rehabilitation therapy. Participants in both groups received therapy five days per week for four weeks. Temporospatial gait characteristics, such as single stance, stance phase, step length, stride, swing phase, velocity, and cadence, were assessed before and after the four weeks therapy period. A significant difference was observed in post-training gains for the single stance (10.32 SD 4.14 vs. 6.54 SD 3.23), step length (8.47 SD 4.12 vs. 4.83 SD 2.14), and stride length (17.03 SD 6.57 vs 10.54 SD 4.34) between the experimental group and the control group (p < 0.05). However, there were no significant differences between two groups on stance phase, swing phase, velocity, cadence, and step width (P > 0.05). We conclude that mirror therapy may be beneficial in improving the effects of stroke on gait ability. © The Author(s) 2014.

Randomized Trial of Intelligent Sensor System for Early Illness Alerts in Senior Housing.

PubMed

Rantz, Marilyn; Phillips, Lorraine J; Galambos, Colleen; Lane, Kari; Alexander, Gregory L; Despins, Laurel; Koopman, Richelle J; Skubic, Marjorie; Hicks, Lanis; Miller, Steven; Craver, Andy; Harris, Bradford H; Deroche, Chelsea B

2017-10-01

Measure the clinical effectiveness and cost effectiveness of using sensor data from an environmentally embedded sensor system for early illness recognition. This sensor system has demonstrated in pilot studies to detect changes in function and in chronic diseases or acute illnesses on average 10 days to 2 weeks before usual assessment methods or self-reports of illness. Prospective intervention study in 13 assisted living (AL) communities of 171 residents randomly assigned to intervention (n=86) or comparison group (n=85) receiving usual care. Intervention participants lived with the sensor system an average of one year. Continuous data collected 24 hours/7 days a week from motion sensors to measure overall activity, an under mattress bed sensor to capture respiration, pulse, and restlessness as people sleep, and a gait sensor that continuously measures gait speed, stride length and time, and automatically assess for increasing fall risk as the person walks around the apartment. Continuously running computer algorithms are applied to the sensor data and send health alerts to staff when there are changes in sensor data patterns. The randomized comparison group functionally declined more rapidly than the intervention group. Walking speed and several measures from GaitRite, velocity, step length left and right, stride length left and right, and the fall risk measure of functional ambulation profile (FAP) all had clinically significant changes. The walking speed increase (worse) and velocity decline (worse) of 0.073 m/s for comparison group exceeded 0.05 m/s, a value considered to be a minimum clinically important difference. No differences were measured in health care costs. These findings demonstrate that sensor data with health alerts and fall alerts sent to AL nursing staff can be an effective strategy to detect and intervene in early signs of illness or functional decline. Copyright © 2017 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

Exoskeleton-assisted gait training to improve gait in individuals with spinal cord injury: a pilot randomized study.

PubMed

Chang, Shuo-Hsiu; Afzal, Taimoor; Berliner, Jeffrey; Francisco, Gerard E

2018-01-01

Robotic wearable exoskeletons have been utilized as a gait training device in persons with spinal cord injury. This pilot study investigated the feasibility of offering exoskeleton-assisted gait training (EGT) on gait in individuals with incomplete spinal cord injury (iSCI) in preparation for a phase III RCT. The objective was to assess treatment reliability and potential efficacy of EGT and conventional physical therapy (CPT). Forty-four individuals were screened, and 13 were eligible to participate in the study. Nine participants consented and were randomly assigned to receive either EGT or CPT with focus on gait. Subjects received EGT or CPT, five sessions a week (1 h/session daily) for 3 weeks. American Spinal Injury Association (ASIA) Lower Extremity Motor Score (LEMS), 10-Meter Walk Test (10MWT), 6-Minute Walk Test (6MWT), Timed Up and Go (TUG) test, and gait characteristics including stride and step length, cadence and stance, and swing phase durations were assessed at the pre- and immediate post- training. Mean difference estimates with 95% confidence intervals were used to analyze the differences. After training, improvement was observed in the 6MWT for the EGT group. The CPT group showed significant improvement in the TUG test. Both the EGT and the CPT groups showed significant increase in the right step length. EGT group also showed improvement in the stride length. EGT could be applied to individuals with iSCI to facilitate gait recovery. The subjects were able to tolerate the treatment; however, exoskeleton size range may be a limiting factor in recruiting larger cohort of patients. Future studies with larger sample size are needed to investigate the effectiveness and efficacy of exoskeleton-assisted gait training as single gait training and combined with other gait training strategies. Clinicaltrials.org, NCT03011099, retrospectively registered on January 3, 2017.

Gait analysis with cognitive-motor dual tasks to distinguish fallers from nonfallers among rehabilitating stroke patients.

PubMed

Baetens, Tina; De Kegel, Alexandra; Palmans, Tanneke; Oostra, Kristine; Vanderstraeten, Guy; Cambier, Dirk

2013-04-01

To evaluate fall risk in stroke patients based on single- and dual-task gait analyses, and to investigate the difference between 2 cognitive tasks in the dual-task paradigm. Prospective cohort study. Rehabilitation hospitals. Subacute stroke patients (N=32), able to walk without physical/manual help with or without walking aids, while performing a verbal task. Not applicable. Functional gait measures were Functional Ambulation Categories (FAC) and use of a walking aid. Gait measures were evaluated by an electronic walkway system under single- and dual-task (DT) conditions. For the single-task, subjects were instructed to walk at their usual speed. One of the DTs was a verbal fluency dual task, whereby subjects had to walk while simultaneously enumerating as many different animals as possible. For the other DT (counting dual task), participants had to walk while performing serial subtractions. After inclusion, participants kept a 6-month falls diary. Eighteen (56.3%) of the 32 included patients fell. Ten (31.3%) were single fallers (SFs), and 8 (25%) were multiple fallers (MFs). Fallers (Fs) more frequently used a walking aid and more frequently needed an observatory person for walking safely (FAC score of 3) than nonfallers (NFs). Two gait decrement parameters in counting dual task could distinguish potential Fs from NFs: decrement in stride length percentage (P=.043) and nonparetic step length percentage (P=.047). Regarding the division in 3 groups (NFs, SFs, and MFs), only MFs had a significantly higher percentage of decrement for paretic step length (P=.023) than SFs. Examining the decrement of spatial gait characteristics (stride length and paretic and nonparetic step length) during a DT addressing working memory can identify fall-prone subacute stroke patients. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Biomechanical characteristics of adults walking forward and backward in water at different stride frequencies.

PubMed

Cadenas-Sánchez, Cristina; Arellano, Raúl; Taladriz, Sonia; López-Contreras, Gracia

2016-01-01

The aim of this study was to examine spatiotemporal characteristics and joint angles during forward and backward walking in water at low and high stride frequency. Eight healthy adults (22.1 ± 1.1 years) walked forward and backward underwater at low (50 pulses) and high frequency (80 pulses) at the xiphoid process level with arms crossed at the chest. The main differences observed were that the participants presented a greater speed (0.58 vs. 0.85 m/s) and more asymmetry of the step length (1.24 vs. 1.48) at high frequency whilst the stride and step length (0.84 vs. 0.7 m and 0.43 vs. 0.35 m, respectively) were lower compared to low frequency (P < 0.05). Support phase duration was higher at forward walking than backward walking (61.2 vs. 59.0%). At initial contact, we showed that during forward walking, the ankle and hip presented more flexion than during backward walking (ankle: 84.0 vs. 91.8º and hip: 22.8 vs. 8.0º; P < 0.001). At final stance, the knee and hip were more flexed at low frequency than at high frequency (knee: 150.0 vs. 157.0º and hip: -12.2 vs. -14.5º; P < 0.001). The knee angle showed more flexion at forward walking (134.0º) than backward walking (173.1º) (P < 0.001). In conclusion, these results show how forward and backward walking in water at different frequencies differ and contribute to a better understanding of this activity in training and rehabilitation.

Stroller running: Energetic and kinematic changes across pushing methods

PubMed Central

Wall-Scheffler, Cara M.

2017-01-01

Objective Running with a stroller provides an opportunity for parents to exercise near their child and counteract health declines experienced during early parenthood. Understanding biomechanical and physiological changes that occur when stroller running is needed to evaluate its health impact, yet the effects of stroller running have not been clearly presented. Here, three commonly used stroller pushing methods were investigated to detect potential changes in energetic cost and lower-limb kinematics. Methods Sixteen individuals (M/F: 10/6) ran at self-selected speeds for 800m under three stroller conditions (2-Hands, 1-Hand, and Push/Chase) and an independent running control. Results A significant decrease in speed (p = 0.001) and stride length (p<0.001) was observed between the control and stroller conditions, however no significant change in energetic cost (p = 0.080) or heart rate (p = 0.393) was observed. Additionally, pushing method had a significant effect on speed (p = 0.001) and stride length (p<0.001). Conclusions These findings suggest that pushing technique influences stroller running speed and kinematics. These findings suggest specific fitness effects may be achieved through the implementation of different pushing methods. PMID:28672004

The value of the NDT-Bobath method in post-stroke gait training.

PubMed

Mikołajewska, Emilia

2013-01-01

Stroke is perceived a major cause of disability, including gait disorders. Looking for more effective methods of gait reeducation in post-stroke survivors is one of the most important issues in contemporary neurorehabilitation. Following a stroke, patients suffer from gait disorders. The aim of this paper is to present the outcomes of a study of post-stroke gait reeducation using the NeuroDevelopmental Treatment-Bobath (NDT-Bobath) method. The research was conducted among 60 adult patients who had undergone ischemic stroke. These patients were treated using the NDT-Bobath method. These patients' gait reeducation was assessed using spatio-temporal gait parameters (gait velocity, cadence and stride length). Measurements of these parameters were conducted by the same therapist twice: on admission, and after the tenth session of gait reeducation. Among the 60 patients involved in the study, the results were as follows: in terms of gait velocity, recovery was observed in 39 cases (65%), in terms of cadence, recovery was observed in 39 cases (65%), in terms of stride length, recovery was observed in 50 cases (83.33%). Benefits were observed after short-term therapy, reflected by measurable statistically significant changes in the patients' gait parameters.

Altered fractal dynamics of gait: reduced stride-interval correlations with aging and Huntington's disease

NASA Technical Reports Server (NTRS)

Hausdorff, J. M.; Mitchell, S. L.; Firtion, R.; Peng, C. K.; Cudkowicz, M. E.; Wei, J. Y.; Goldberger, A. L.

1997-01-01

Fluctuations in the duration of the gait cycle (the stride interval) display fractal dynamics and long-range correlations in healthy young adults. We hypothesized that these stride-interval correlations would be altered by changes in neurological function associated with aging and certain disease states. To test this hypothesis, we compared the stride-interval time series of 1) healthy elderly subjects and young controls and of 2) subjects with Huntington's disease and healthy controls. Using detrended fluctuation analysis we computed alpha, a measure of the degree to which one stride interval is correlated with previous and subsequent intervals over different time scales. The scaling exponent alpha was significantly lower in elderly subjects compared with young subjects (elderly: 0.68 +/- 0.14; young: 0.87 +/- 0.15; P < 0.003). The scaling exponent alpha was also smaller in the subjects with Huntington's disease compared with disease-free controls (Huntington's disease: 0.60 +/- 0.24; controls: 0.88 +/-0.17; P < 0.005). Moreover, alpha was linearly related to degree of functional impairment in subjects with Huntington's disease (r = 0.78, P < 0.0005). These findings demonstrate that strike-interval fluctuations are more random (i.e., less correlated) in elderly subjects and in subjects with Huntington's disease. Abnormal alterations in the fractal properties of gait dynamics are apparently associated with changes in central nervous system control.

Does external walking environment affect gait patterns?

PubMed

Patterson, Matthew R; Whelan, Darragh; Reginatto, Brenda; Caprani, Niamh; Walsh, Lorcan; Smeaton, Alan F; Inomata, Akihiro; Caulfield, Brian

2014-01-01

The objective of this work is to develop an understanding of the relationship between mobility metrics obtained outside of the clinic or laboratory and the context of the external environment. Ten subjects walked with an inertial sensor on each shank and a wearable camera around their neck. They were taken on a thirty minute walk in which they mobilized over the following conditions; normal path, busy hallway, rough ground, blind folded and on a hill. Stride time, stride time variability, stance time and peak shank rotation rate during swing were calculated using previously published algorithms. Stride time was significantly different between several of the conditions. Technological advances mean that gait variables can now be captured as patients go about their daily lives. The results of this study show that the external environment has a significant impact on the quality of gait metrics. Thus, context of external walking environment is an important consideration when analyzing ambulatory gait metrics from the unsupervised home and community setting.

The effect of cadence on the muscle-tendon mechanics of the gastrocnemius muscle during walking.

PubMed

Brennan, S F; Cresswell, A G; Farris, D J; Lichtwark, G A

2017-03-01

Humans naturally select a cadence that minimizes metabolic cost at a constant walking velocity. The aim of this study was to examine the effects of cadence on the medial gastrocnemius (MG) muscle and tendon interaction, and examine how this might influence lower limb energetics. We hypothesized that cadences higher than preferred would increase MG fascicle shortening velocity because of the reduced stride time. Furthermore, we hypothesized that cadences lower than preferred would require greater MG fascicle shortening to achieve increased muscle work requirements. We measured lower limb kinematics and kinetics, surface electromyography of the triceps surae and MG fascicle length, via ultrasonography, during walking at a constant velocity at the participants' preferred cadence and offsets of ±10%, ±20%, and ±30%. There was a significant increase in MG fascicle shortening with decreased cadence. However, there was no increase in the MG fascicle shortening velocity at cadences higher than preferred. Cumulative MG muscle activation per minute was significantly increased at higher cadences. We conclude that low cadence walking requires more MG shortening work, while MG muscle and tendon function changes little for each stride at higher cadences, driving up cumulative activation costs due to the increase in steps per minute. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Technology-assisted balance and gait training reduces falls in patients with Parkinson's disease: a randomized controlled trial with 12-month follow-up.

PubMed

Shen, Xia; Mak, Margaret K Y

2015-02-01

Objective. To examine the effects of technology-assisted balance and gait training on reducing falls in patients with Parkinson's disease (PD). Methods. Eligible subjects were randomly allocated to an experimental group given technology-assisted balance and gait training (BAL, n = 26) and an active control group undertaking strengthening exercises (CON, n = 25). The training in each group lasted for 3 months. The number of fallers and fall rate were used as primary outcomes, and single-leg-stance-time, latency of postural response to perturbation, self-selected gait velocity, and stride length as secondary outcomes. Fall incidence was recorded over 15 months after the baseline assessment (Pre). Other tests were performed at Pre, after 3-month intervention (Post(3m)), at 3 months (Post(6m)), and 12 months (Post(15m)) after treatment completion. Results. Forty-five subjects who completed the 3-month training were included in the data analysis. There were fewer fallers in the BAL than in the CON group at Post(3m), Post(6m), and Post(15m) (P < .05). In addition, the BAL group had lower fall rate than the CON group at Post(3m) and Post(6m) (incidence rate ratio: 0.111-0.188, P < .05), and marginally so at Post(15m) (incidence rate ratio: 0.407, P = .057). Compared with the CON subjects, the BAL subjects demonstrated greater reduction in the postural response latency and increase in the stride length against baseline at each assessment interval (P < .05), and marginally more increases of single-leg-stance-time at Post(3m) (P = .064), Post(6m) (P = .041) and Post(15m) (P = .087). Conclusions. Our positive findings provide evidence for the clinical use of technology-assisted balance and gait training in reducing falls in people with PD. © The Author(s) 2014.

Influence of visual and auditory biofeedback on partial body weight support treadmill training of individuals with chronic hemiparesis: a randomized controlled clinical trial.

PubMed

Brasileiro, A; Gama, G; Trigueiro, L; Ribeiro, T; Silva, E; Galvão, É; Lindquist, A

2015-02-01

Stroke is an important causal factor of deficiency and functional dependence worldwide. To determine the immediate effects of visual and auditory biofeedback, combined with partial body weight supported (PBWS) treadmill training on the gait of individuals with chronic hemiparesis. Randomized controlled trial. Outpatient rehabilitation hospital. Thirty subjects with chronic hemiparesis and ability to walk with some help. Participants were randomized to a control group that underwent only PBWS treadmill training; or experimental I group with visual biofeedback from the display monitor, in the form of symbolic feet as the subject took a step; or experimental group II with auditory biofeedback associated display, using a metronome at 115% of the individual's preferred cadence. They trained for 20 minutes and were evaluated before and after training. Spatio-temporal and angular gait variables were obtained by kinematics from the Qualisys Motion Analysis system. Increases in speed and stride length were observed for all groups over time (speed: F=25.63; P<0.001; stride length: F=27.18; P<0.001), as well as changes in hip and ankle range of motion - ROM (hip ROM: F=14.43; P=0.001; ankle ROM: F=4.76; P=0.038), with no time*groups interaction. Other spatio-temporal and angular parameters remain unchanged. Visual biofeedback and auditory biofeedback had no influence on PBWS treadmill training of individuals with chronic hemiparesis, in short term. Additional studies are needed to determine whether, in long term, the biofeedback will promote additional benefit to the PBWS treadmill training. The findings of this study indicate that visual and auditory biofeedback does not bring immediate benefits on PBWS treadmill training of individuals with chronic hemiparesis. This suggest that, for additional benefits are achieved with biofeedback, effects should be investigated after long-term training, which may determine if some kind of biofeedback is superior to another to improve the hemiparetic gait.

Virtual Reality-Based Training to Improve Obstacle-Crossing Performance and Dynamic Balance in Patients With Parkinson's Disease.

PubMed

Liao, Ying-Yi; Yang, Yea-Ru; Cheng, Shih-Jung; Wu, Yih-Ru; Fuh, Jong-Ling; Wang, Ray-Yau

2015-08-01

Obstacle crossing is a balance-challenging task and can cause falls in people with Parkinson's disease (PD). However, programs for people with PD that effectively target obstacle crossing and dynamic balance have not been established. To examine the effects of virtual reality-based exercise on obstacle crossing performance and dynamic balance in participants with PD. Thirty-six participants with a diagnosis of PD (Hoehn and Yahr score ranging 1 to 3) were randomly assigned to one of three groups. In the exercise groups, participants received virtual reality-based Wii Fit exercise (VRWii group) or traditional exercise (TE group) for 45 minutes, followed by 15 minutes of treadmill training in each session for a total of 12 sessions over 6 weeks. Participants in the control group received no structured exercise program. Primary outcomes included obstacle crossing performance (crossing velocity, stride length, and vertical toe obstacle clearance) and dynamic balance (maximal excursion, movement velocity, and directional control measured by the limits-of-stability test). Secondary outcomes included sensory organization test (SOT), Parkinson's Disease Questionnaire (PDQ39), fall efficacy scale (FES-I), and timed up and go test (TUG). All outcomes were assessed at baseline, after training, and at 1-month follow-up. The VRWii group showed greater improvement in obstacle crossing velocity, crossing stride length, dynamic balance, SOT, TUG, FES-I, and PDQ39 than the control group. VRWii training also resulted in greater improvement in movement velocity of limits-of-stability test than TE training. VRWii training significantly improved obstacle crossing performance and dynamic balance, supporting implementation of VRWii training in participants with PD. © The Author(s) 2014.

Stride search: A general algorithm for storm detection in high resolution climate data

DOE PAGES

Bosler, Peter Andrew; Roesler, Erika Louise; Taylor, Mark A.; ...

2015-09-08

This article discusses the problem of identifying extreme climate events such as intense storms within large climate data sets. The basic storm detection algorithm is reviewed, which splits the problem into two parts: a spatial search followed by a temporal correlation problem. Two specific implementations of the spatial search algorithm are compared. The commonly used grid point search algorithm is reviewed, and a new algorithm called Stride Search is introduced. Stride Search is designed to work at all latitudes, while grid point searches may fail in polar regions. Results from the two algorithms are compared for the application of tropicalmore » cyclone detection, and shown to produce similar results for the same set of storm identification criteria. The time required for both algorithms to search the same data set is compared. Furthermore, Stride Search's ability to search extreme latitudes is demonstrated for the case of polar low detection.« less

Neuromuscular adjustments of gait associated with unstable conditions

PubMed Central

Ivanenko, Y. P.; d'Avella, A.; Serrao, M.; Ranavolo, A.; Draicchio, F.; Cappellini, G.; Casali, C.; Lacquaniti, F.

2015-01-01

A compact description of coordinated muscle activity is provided by the factorization of electromyographic (EMG) signals. With the use of this approach, it has consistently been shown that multimuscle activity during human locomotion can be accounted for by four to five modules, each one comprised of a basic pattern timed at a different phase of gait cycle and the weighting coefficients of synergistic muscle activations. These modules are flexible, in so far as the timing of patterns and the amplitude of weightings can change as a function of gait speed and mode. Here we consider the adjustments of the locomotor modules related to unstable walking conditions. We compared three different conditions, i.e., locomotion of healthy subjects on slippery ground (SL) and on narrow beam (NB) and of cerebellar ataxic (CA) patients on normal ground. Motor modules were computed from the EMG signals of 12 muscles of the right lower limb using non-negative matrix factorization. The unstable gait of SL, NB, and CA showed significant changes compared with controls in the stride length, stride width, range of angular motion, and trunk oscillations. In most subjects of all three unstable conditions, >70% of the overall variation of EMG waveforms was accounted for by four modules that were characterized by a widening of muscle activity patterns. This suggests that the nervous system adopts the strategy of prolonging the duration of basic muscle activity patterns to cope with unstable conditions resulting from either slippery ground, reduced support surface, or pathology. PMID:26378199

Reliability of spatial-temporal gait parameters during dual-task interference in people with multiple sclerosis. A cross-sectional study.

PubMed

Monticone, Marco; Ambrosini, Emilia; Fiorentini, Roberta; Rocca, Barbara; Liquori, Valentina; Pedrocchi, Alessandra; Ferrante, Simona

2014-09-01

To evaluate the reliability and minimum detectable change (MDC) of spatial-temporal gait parameters in subjects with multiple sclerosis (MS) during dual tasking. This cross-sectional study involved 25 healthy subjects (mean age 49.9 ± 15.8 years) and 25 people with MS (mean age 49.2 ± 11.5 years). Gait under motor-cognitive and motor-motor dual tasking conditions was evaluated in two sessions separated by a one-day interval using the GAITRite Walkway System. Test-retest reliability was assessed using intraclass correlation coefficients (ICCs), standard errors of measurement (SEM), and coefficients of variation (CV). MDC scores were computed for the velocity, cadence, step and stride length, step and stride time, double support time, the % of gait cycle for single support and stance phase, and base of support. All of the gait parameters reported good to excellent ICCs under both conditions, with healthy subject values of >0.69 and MS subject values of >0.84. SEM values were always below 18% for both groups of subjects. The gait patterns of the people with MS were slightly more variable than those of the normal controls (CVs: 5.88-41.53% vs 2.84-30.48%). The assessment of quantitative gait parameters in healthy subjects and people with MS is highly reliable under both of the investigated dual tasking conditions. Copyright © 2014 Elsevier B.V. All rights reserved.

Interrater reliability of videotaped observational gait-analysis assessments.

PubMed

Eastlack, M E; Arvidson, J; Snyder-Mackler, L; Danoff, J V; McGarvey, C L

1991-06-01

The purpose of this study was to determine the interrater reliability of videotaped observational gait-analysis (VOGA) assessments. Fifty-four licensed physical therapists with varying amounts of clinical experience served as raters. Three patients with rheumatoid arthritis who demonstrated an abnormal gait pattern served as subjects for the videotape. The raters analyzed each patient's most severely involved knee during the four subphases of stance for the kinematic variables of knee flexion and genu valgum. Raters were asked to determine whether these variables were inadequate, normal, or excessive. The temporospatial variables analyzed throughout the entire gait cycle were cadence, step length, stride length, stance time, and step width. Generalized kappa coefficients ranged from .11 to .52. Intraclass correlation coefficients (2,1) and (3,1) were slightly higher. Our results indicate that physical therapists' VOGA assessments are only slightly to moderately reliable and that improved interrater reliability of the assessments of physical therapists utilizing this technique is needed. Our data suggest that there is a need for greater standardization of gait-analysis training.

Mechanical Analysis of the Acute Effects of a Heavy Resistance Exercise Warm-Up on Agility Performance in Court-Sport Athletes

PubMed Central

Sole, Christopher J.; Moir, Gavin L.; Davis, Shala E.; Witmer, Chad A.

2013-01-01

The purpose of this study was to determine the acute effects of heavy resistance exercise on agility performance in court-sport athletes. Five men (age: 20.6 ± 1.9 years; body mass: 79.36 ± 11.74 kg; body height: 1.93 ± 0.09 m) and five women (age 21.2 ± 2.7 years; body mass: 65.8 ± 10.18 kg; body height 1.77 ± 0.08 m) volunteered to participate in the present study. All subjects were NCAA Division II athletes who currently participated in tennis or basketball and all had previous resistance training experience of at least one year. In a counterbalanced design, agility performance during a 10 m shuttle test was assessed following either a dynamic warm-up (DW) or heavy resistance warm-up (HRW) protocol. The HRW protocol consisted of three sets of squats at 50, 60, and 90% of 1-RM. Agility performance was captured using an eight camera motion analysis system and the mechanical variables of stride length, stride frequency, stance time, flight time, average ground reaction force, as well as agility time were recorded. No significant differences were reported for the HRW and DW protocols for any of the mechanical variables (p>0.05), although there was a trend towards the HRW protocol producing faster agility times compared to the control protocol (p = 0.074). Based on the trend towards a significant effect, as well as individual results it is possible that HRW protocols could be used as an acute method to improve agility performance in some court-sport athletes. PMID:24511350

Correlation among Y Balance Test-Lower Quarter Composite Scores, Hip Musculoskeletal Characteristics, and Pitching Kinematics in NCAA Division I Baseball Pitchers.

PubMed

Culiver, Adam; Garrison, J Craig; Creed, Kalyssa M; Conway, John E; Goto, Shiho; Werner, Sherry

2018-01-24

Numerous studies have reported kinematic data on baseball pitchers using 3D motion analysis, but no studies to date have correlated this data with clinical outcome measures. To examine the relationship among Y Balance Test-Lower Quarter (YBT-LQ) composite scores, musculoskeletal characteristics of the hip and pitching kinematics in NCAA Division I baseball pitchers. Cross-sectional. 3D motion analysis laboratory. 19 healthy male collegiate baseball pitchers. Internal and external hip passive range of motion (PROM); hip abduction strength; YBT-LQ composite scores; kinematic variables of the pitching motion. Stride length demonstrated a moderate positive correlation with dominant limb YBT-LQ composite score (r=0.524, p=0.018) and non-dominant limb YBT-LQ composite score (r=0.550, p=0.012), and a weak positive correlation with normalized time to maximal humerus velocity (r=0.458, p=0.043). Stride length had a moderate negative correlation with normalized time to maximal thorax velocity (r= -0.522, p=0.018) and dominant hip TRM (r= -0.660, p=0.002), and had a strong negative correlation with normalized time from SFC to maximal knee flexion (r= -0.722, p<0.001). Dominant limb YBT-LQ composite score had a weak negative correlation with hip abduction strength difference (r= -0.459, p=0.042) and normalized time to maximal thorax velocity (r= -0.468, p=0.037), as well as a moderate negative correlation with dominant hip TRM (r= -0.160, p=0.004). Non-dominant limb YBT-LQ composite score demonstrated a weak negative correlation with normalized time to maximal thorax velocity (r= -0.450, p=0.046) and had a moderate negative correlation with dominant hip TRM (r= -0.668, p=0.001). Hip abduction strength difference demonstrated a weak positive correlation with dominant hip TRM (r=0.482, p=0.032). Dominant hip TRM had a moderate positive correlation with normalized time to maximal thorax velocity (r=0.484, p=0.031). There were no other significant relationships between the remaining variables. YBT-LQ is a clinical measure which can be used to correlate with hip musculoskeletal characteristics and pitching kinematics in NCAA Division I pitchers.

[The concept and definition of locomotive syndrome in a super-aged society].

PubMed

Nakamura, Kozo; Yoshimura, Noriko; Akune, Toru; Ogata, Toru; Tanaka, Sakae

2014-10-01

The population of elderly individuals who need nursing care is rapidly increasing in Japan. Locomotive syndrome involves a decrease in mobility due to locomotive organ dysfunction, and increases risk for dependency on nursing care service. Because gait speed and chair stand time are correlated with such risks, patients with locomotive syndrome are assessed using brief methods such as the two-step test, which involves dividing the maximum stride length by the height of the patient, and the stand-up test, which involves standing on one or both legs at different heights. One leg standing and squatting are recommended as beneficial locomotive home exercises. Locomotive syndrome has been recognized widely in Japan, and included in the National Health Promotion Movement (2013-2022).

Effects of glycine on motor performance in rats after traumatic spinal cord injury.

PubMed

Gonzalez-Piña, Rigoberto; Nuño-Licona, Alberto

2007-01-01

It has been reported that glycine improves some functions lost after spinal cord injury (SCI). In order to assess the effects of glycine administration on motor performance after SCI, we used fifteen male Wistar rats distributed into three groups: sham (n = 3), spinal-cord injury (n = 6,) and spinal cord injury + glycine (n = 6). Motor performance was assessed using the beam-walking paradigm and footprint analysis. Results showed that for all animals with spinal-cord injury, scores in the beam-walking increased, which is an indication of increased motor deficit. In addition, footprint analysis showed a decrease in stride length and an increase in stride angle, additional indicators of motor deficit. These effects trended towards recovery after 8 weeks of recording and trended toward improvement by glycine administration; the effect was not significant. These results suggest that glycine replacement alone is not sufficient to improve the motor deficits that occur after SCI.

Lower Limb Rehabilitation Using Patient Data

PubMed Central

Saadat, Mozafar

2016-01-01

The aim of this study is to investigate the performance of a 6-DoF parallel robot in tracking the movement of the foot trajectory of a paretic leg during a single stride. The foot trajectories of nine patients with a paretic leg including both males and females have been measured and analysed by a Vicon system in a gait laboratory. Based on kinematic and dynamic analysis of a 6-DoF UPS parallel robot, an algorithm was developed in MATLAB to calculate the length of the actuators and their required forces during all trajectories. The workspace and singularity points of the robot were then investigated in nine different cases. A 6-DoF UPS parallel robot prototype with high repeatability was designed and built in order to simulate a single stride. Results showed that the robot was capable of tracking all of the trajectories with the maximum position error of 1.2 mm. PMID:27721648

Anti-dementia drugs and changes in gait: a pre-post quasi-experimental pilot study.

PubMed

Beauchet, Olivier; Launay, Cyrille P; Allali, Gazan; Watfa, Gilles; Gallouj, Karim; Herrmann, François R; Annweiler, Cédric

2013-11-21

Anti-dementia drugs may improve gait performance. No comparison between acetylcholinesterase inhibitors (CEIs) and memantine-related changes in gait variability has been reported. The objectives of this study were to 1) quantify and compare the mean values and coefficients of variation (CoV) of stride time in demented patients with Alzheimer's disease and related disorders (ADRD) before and after the use of CEIs or memantine, and in age- and gender-matched controls patients with ADRD using no anti-dementia drugs; and 2) to determine whether changes in CoV of stride time differed between CEIs or memantine. A total of 120 demented patients with mild-to-moderate ADRD were prospectively included in this pre-post quasi-experimental study with two intervention groups (43 patients taking CEIs, and 41 taking memantine) and a control group (36 age- and gender matched patients without any anti-dementia drugs). CoV of stride time and walking speed were measured with GAITRite® system while usual walking at steady state. Age, gender, number of drugs daily taken, use of psychoactive drugs, body mass index and time between the two visits were also recorded. There was no difference between groups for the time between baseline and follow-up assessments (232.9 ± 103.7 days for patients without anti-dementia drugs, 220.0 ± 67.5 days for patients with CEIs, 186.7 ± 96.2 days for patients with memantine, P = 0.062). Patients with memantine had a lower (i.e., better) CoV of stride time at follow-up assessment compared to those with CEIs (4.2 ± 2.4% versus 5.8 ± 4.2%, P = 0.010). Patients with memantine had a greater decrease in CoV of stride time compared to those with CEIs (-1.90% versus 0.93%, P = 0.010) and mixed-effects linear regressions showed that this decrease was specifically explained by memantine (P = 0.028). Our results showed that patients with ADRD and treated with memantine, but not those with CEIs, decreased their gait variability, and thus improved their gait safety (Trial registration number: NCT01315704).

Clinical usefulness of augmented reality using infrared camera based real-time feedback on gait function in cerebral palsy: a case study

PubMed Central

Lee, Byoung-Hee

2016-01-01

[Purpose] This study investigated the effects of real-time feedback using infrared camera recognition technology-based augmented reality in gait training for children with cerebral palsy. [Subjects] Two subjects with cerebral palsy were recruited. [Methods] In this study, augmented reality based real-time feedback training was conducted for the subjects in two 30-minute sessions per week for four weeks. Spatiotemporal gait parameters were used to measure the effect of augmented reality-based real-time feedback training. [Results] Velocity, cadence, bilateral step and stride length, and functional ambulation improved after the intervention in both cases. [Conclusion] Although additional follow-up studies of the augmented reality based real-time feedback training are required, the results of this study demonstrate that it improved the gait ability of two children with cerebral palsy. These findings suggest a variety of applications of conservative therapeutic methods which require future clinical trials. PMID:27190489

Effect of hoof boots and toe-extension shoes on the forelimb kinetics of horses during walking.

PubMed

Amitrano, Fernando N; Gutierrez-Nibeyro, Santiago D; Schaeffer, David J

2016-05-01

OBJECTIVE To determine and compare the effect of hoof boots (HBs) and shoes with a toe extension on stance duration, ground reaction force, and sole length in contact with the ground in nonlame horses during walking. ANIMALS 6 nonlame Standardbreds. PROCEDURES Force plate gait analyses of the forelimbs were performed while the horses were walking barefoot before manipulation of feet (baseline), while the horses were walking fitted with HBs, while the horses were walking shod with toe-extension shoes, and while the horses were walking barefoot after shoe removal. Horses underwent radiography of both forelimb feet to determine the sole length in contact with the ground when barefoot, wearing HBs, and shod with toe-extension shoes. Stance duration, ground reaction force, and sole length were compared among the various walking sessions. RESULTS Compared with baseline findings, stance duration increased significantly when horses were fitted with HBs (7%) or toe-extension shoes (5%). Peak forelimb ground reaction force was similar among walking sessions; however, time of braking force peak was significantly greater during the stance phase only when horses wore HBs. Also, the sole length in contact with the ground was significantly longer in horses fitted with HBs (14.3 cm) or shod with the toe-extension shoes (17.6 cm), compared with that for one of the barefoot hooves (12.7 cm). CONCLUSIONS AND CLINICAL RELEVANCE In nonlame horses, use of HBs prolonged the stance time and time of braking force peak, which is indicative of a slower deceleration phase during limb impact with the ground. Also, the use of HBs prolonged the deceleration phase of the stride and increased the sole length in contact with the ground.

Greater Fall Risk in Elderly Women Than in Men Is Associated With Increased Gait Variability During Multitasking.

PubMed

Johansson, Jonas; Nordström, Anna; Nordström, Peter

2016-06-01

As 90% of fractures are caused by falls, and as fractures are more common in elderly women than in elderly men, a better understanding of potential sex differences in fall rates and underlying mechanisms is needed. The purpose of this study was to determine whether women are more prone than men to falling, and to evaluate whether the risk of falling is associated with variations in gait patterns. The cohort for this prospective observational study consisted of 1390 community-dwelling men and women aged 70 years, examined in a health survey between July 2012 and November 2014. Gait patterns were measured using a computerized walkway system during normal-speed, fast-speed, and dual-task trials. Triaxial accelerometers were used to collect objective data on physical activity, and self-reported fall data were collected by telephone 6 and 12 months after examination. Incident low-energy falls were defined as unexpected events in which participants came to rest on the ground. During the follow-up period, 148 study participants (88 women, 60 men; P = .01) reported falls. After adjusting for multiple confounders, including objective measures of physical activity, socioeconomic factors, cardiovascular disease, and cognitive function, the odds ratio for falling in women was 1.49 (95% confidence interval [CI] 1.02-2.19). Variations in gait pattern were significantly (20%-40%) increased in fallers compared with nonfallers during the dual-task trial for step width, step length, stride length, step time, stance time, stride velocity, and single support time (all P < .05). Furthermore, women showed 15% to 35% increased variability in all of these gait parameters during the dual-task trial compared with men (all P < .01). In the present cohort, 70-year-old women were at greater risk of falls compared with their male counterparts. This increased risk was associated with increased variation in gait pattern during dual-task activities, and may contribute to women's greater fracture risk compared with men. Copyright © 2016 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

Correlations between Berg balance scale and gait speed in individuals with stroke wearing ankle-foot orthoses - a pilot study.

PubMed

Kobayashi, Toshiki; Leung, Aaron K L; Akazawa, Yasushi; Hutchins, Stephen W

2016-01-01

The Berg balance scale (BBS) is commonly used to assess balancing ability in patients with stroke. The BBS may be a good candidate for clinical assessment prior to orthotic intervention, if it correlates well with outcome measures such as gait speed. The purpose of this study was to investigate the correlation between the BBS measured prior to walking with an ankle-foot orthosis (AFO) and specific temporal-spatial parameters of gait when walking with an AFO donned. Eight individuals with chronic stroke participated in this study. Balancing ability was assessed using the BBS, while temporal-spatial parameters of gait (gait speed, bilateral step length, stride length and step width) were measured using a three-dimensional motion analysis system. The correlations between the BBS and gait parameters were investigated using a non-parametric Kendall's Tau (τ) correlation analysis. The BBS showed correlations with gait speed (τ = 0.64, p < 0.05), the step length of the affected side (τ = 0.74, p < 0.05), and the stride length (τ = 0.64, p < 0.05). Assessment of the BBS prior to AFO prescription may potentially help clinicians to estimate the gait speed achievable following orthotic intervention in patients with stroke. Implications for Rehabilitation Assessment of the BBS prior to AFO prescription may help orthotists to estimate the gait speed following an orthotic intervention in patients with stroke. Assessment of the BBS prior to AFO prescription may help orthotists to understand overall balance and postural control abilities in patients with stroke. A larger scale multifactorial analysis is warranted to confirm the results of this pilot study.

Three-Dimensional Kinematic Gait Analysis of Doberman Pinschers with and without Cervical Spondylomyelopathy

PubMed Central

Foss, K.; da Costa, R.C.; Moore, S.

2014-01-01

Background The optimal treatment of cervical spondylomyelopathy (CSM) is controversial, with the owner’s and clinician’s perception of gait improvement often being used as outcome measures. These methods are subjective and suffer from observer bias. Objectives To establish kinematic gait parameters utilizing digital motion capture in normal Doberman Pinschers and compare them with CSM-affected Dobermans. Animals Nineteen Doberman Pinschers; 10 clinically normal and 9 with CSM. Methods All dogs were enrolled prospectively and fitted with a Lycra® body suit, and motion capture was performed and used to reconstruct a 3-D stick diagram representation of each dog based on 32 reflective markers, from which several parameters were measured. These included stride duration, length, and height; maximal and minimal spinal angles; elbow and stifle flexion and extension; and maximum and minimum distances between the thoracic and pelvic limbs. A random-effects linear regression model was used to compare parameters between groups. Results Significant differences between groups included smaller minimum (mean = 116 mm; P = .024) and maximum (mean = 184 mm; P = .001) distance between the thoracic limbs in CSM-affected dogs. Additionally, thoracic limb stride duration was also smaller (P = .009) in CSM-affected dogs (mean = 0.7 seconds) when compared with normal dogs (mean = 0.8 seconds). In the pelvic limbs, the average stifle flexion (mean = 100°; P = .048) and extension (mean = 136°; P = .009), as well as number of strides (mean = 2.7 strides; P = .033) were different between groups. Conclusions and Clinical Importance Our findings suggest that computerized gait analysis reveals more consistent kinematic differences in the thoracic limbs, which can be used as future objective outcome measures. PMID:23194100

Using step width to compare locomotor biomechanics between extinct, non-avian theropod dinosaurs and modern obligate bipeds.

PubMed

Bishop, P J; Clemente, C J; Weems, R E; Graham, D F; Lamas, L P; Hutchinson, J R; Rubenson, J; Wilson, R S; Hocknull, S A; Barrett, R S; Lloyd, D G

2017-07-01

How extinct, non-avian theropod dinosaurs locomoted is a subject of considerable interest, as is the manner in which it evolved on the line leading to birds. Fossil footprints provide the most direct evidence for answering these questions. In this study, step width-the mediolateral (transverse) distance between successive footfalls-was investigated with respect to speed (stride length) in non-avian theropod trackways of Late Triassic age. Comparable kinematic data were also collected for humans and 11 species of ground-dwelling birds. Permutation tests of the slope on a plot of step width against stride length showed that step width decreased continuously with increasing speed in the extinct theropods ( p < 0.001), as well as the five tallest bird species studied ( p < 0.01). Humans, by contrast, showed an abrupt decrease in step width at the walk-run transition. In the modern bipeds, these patterns reflect the use of either a discontinuous locomotor repertoire, characterized by distinct gaits (humans), or a continuous locomotor repertoire, where walking smoothly transitions into running (birds). The non-avian theropods are consequently inferred to have had a continuous locomotor repertoire, possibly including grounded running. Thus, features that characterize avian terrestrial locomotion had begun to evolve early in theropod history. © 2017 The Author(s).

[Gait characteristics of women with fibromyalgia: a premature aging pattern].

PubMed

Góes, Suelen M; Leite, Neiva; de Souza, Ricardo M; Homann, Diogo; Osiecki, Ana C V; Stefanello, Joice M F; Rodacki, André L F

2014-01-01

Fibromyalgia is a condition which involves chronic pain. Middle-aged individuals with fibromyalgia seem to exhibit changes in gait pattern, which may prematurely expose them to a gait pattern which resembles that found in the elderly population. To determine the 3D spatial (linear and angular) gait parameters of middle-aged women with fibromyalgia and compare to elderly women without this condition. 25 women (10 in the fibromyalgia group and 15 in the elderly group) volunteered to participate in the study. Kinematics was performed using an optoelectronic system, and linear and angular kinematic variables were determined. There was no difference in walking speed, stride length, cadence, hip, knee and ankle joints range of motion between groups, except the pelvic rotation, in which the fibromyalgia group showed greater rotation (P<0.05) compared to the elderly group. Also, there was a negative correlation with pelvic rotation and gluteus pain (r = -0.69; P<0.05), and between pelvic obliquity and greater trochanter pain (r = -0.69; P<0.05) in the fibromyalgia group. Middle-aged women with fibromyalgia showed gait pattern resemblances to elderly, women, which is characterized by reduced lower limb ROM, stride length and walking speed. Copyright © 2014 Elsevier Editora Ltda. All rights reserved.

The influence of water depth on kinematic and spatiotemporal gait parameters during aquatic treadmill walking.

PubMed

Jung, Taeyou; Kim, Yumi; Lim, Hyosok; Vrongistinos, Konstantinos

2018-01-16

The purpose of this study was to investigate kinematic and spatiotemporal variables of aquatic treadmill walking at three different water depths. A total of 15 healthy individuals completed three two-minute walking trials at three different water depths. The aquatic treadmill walking was conducted at waist-depth, chest-depth and neck-depth, while a customised 3-D underwater motion analysis system captured their walking. Each participant's self-selected walking speed at the waist level was used as a reference speed, which was applied to the remaining two test conditions. A repeated measures ANOVA showed statistically significant differences among the three walking conditions in stride length, cadence, peak hip extension, hip range of motion (ROM), peak ankle plantar flexion and ankle ROM (All p values < 0.05). The participants walked with increased stride length and decreased cadence during neck level as compared to waist and chest level. They also showed increased ankle ROM and decreased hip ROM as the water depth rose from waist and chest to the neck level. However, our study found no significant difference between waist and chest level water in all variables. Hydrodynamics, such as buoyancy and drag force, in response to changes in water depths, can affect gait patterns during aquatic treadmill walking.

Dalfampridine in Parkinson's disease related gait dysfunction: A randomized double blind trial.

PubMed

Luca, Corneliu C; Nadayil, Gloria; Dong, Chuanhui; Nahab, Fatta B; Field-Fote, Edelle; Singer, Carlos

2017-08-15

Disease-related gait dysfunction causes extensive disability for persons with Parkinson's disease (PD), with no effective therapies currently available. The potassium channel blocker dalfampridine has been used in multiple neurological conditions and improves walking in persons with multiple sclerosis. We aimed to evaluate the effect of dalfampridine extended release (D-ER) 10mg tablets twice daily on different domains of walking in participants with PD. Twenty-two participants with PD and gait dysfunction were randomized to receive D-ER 10mg twice daily or placebo for 4weeks in a crossover design with a 2-week washout period. The primary outcomes were change in the gait velocity and stride length. At 4weeks, gait velocity was not significantly different between D-ER (0.89m/s±0.33) and placebo (0.93m/s±0.27) conditions. The stride length was also similar between conditions: 0.96m±0.38 for D-ER versus 1.06m±0.33 for placebo. D-ER was generally well tolerated with the most frequent side effects being dizziness, nausea and balance problems. D-ER is well tolerated in PD patients, however it did not show significant benefit for gait impairment. Copyright © 2017 Elsevier B.V. All rights reserved.

Impact Accelerations of Barefoot and Shod Running.

PubMed

Thompson, M; Seegmiller, J; McGowan, C P

2016-05-01

During the ground contact phase of running, the body's mass is rapidly decelerated resulting in forces that propagate through the musculoskeletal system. The repetitive attenuation of these impact forces is thought to contribute to overuse injuries. Modern running shoes are designed to reduce impact forces, with the goal to minimize running related overuse injuries. Additionally, the fore/mid foot strike pattern that is adopted by most individuals when running barefoot may reduce impact force transmission. The aim of the present study was to compare the effects of the barefoot running form (fore/mid foot strike & decreased stride length) and running shoes on running kinetics and impact accelerations. 10 healthy, physically active, heel strike runners ran in 3 conditions: shod, barefoot and barefoot while heel striking, during which 3-dimensional motion analysis, ground reaction force and accelerometer data were collected. Shod running was associated with increased ground reaction force and impact peak magnitudes, but decreased impact accelerations, suggesting that the midsole of running shoes helps to attenuate impact forces. Barefoot running exhibited a similar decrease in impact accelerations, as well as decreased impact peak magnitude, which appears to be due to a decrease in stride length and/or a more plantarflexed position at ground contact. © Georg Thieme Verlag KG Stuttgart · New York.

Effect of rhythmic auditory stimulation on gait performance in children with spastic cerebral palsy.

PubMed

Kwak, Eunmi Emily

2007-01-01

The purpose of this study was to use Rhythmic Auditory Stimulation (RAS) for children with spastic cerebral palsy (CP) in a clinical setting in order to determine its effectiveness in gait training for ambulation. RAS has been shown to improve gait performance in patients with significant gait deficits. All 25 participants (6 to 20 years old) had spastic CP and were ambulatory, but needed to stabilize and gain more coordinated movement. Participants were placed in three groups: the control group, the therapist-guided training (TGT) group, and the self-guided training (SGT) group. The TGT group showed a statistically significant difference in stride length, velocity, and symmetry. The analysis of the results in SGT group suggests that the self-guided training might not be as effective as therapist-guided depending on motivation level. The results of this study support three conclusions: (a) RAS does influence gait performance of people with CP; (b) individual characteristics, such as cognitive functioning, support of parents, and physical ability play an important role in designing a training application, the effectiveness of RAS, and expected benefits from the training; and (c) velocity and stride length can be improved by enhancing balance, trajectory, and kinematic stability without increasing cadence.

Steeplechase barriers affect women less than men.

PubMed

Hunter, Iain; Bushnell, Tyler D

2006-01-01

Women began contesting the 3000 m steeplechase during the 1990's using barriers of different dimensions than men. Whenever a new event is introduced for women, consideration should be taken as to whether different technique or training methods should be utilized. This study investigated three aspects of hurdling technique: 1) Differences in the ratio of the landing step to the penultimate step between men and women around each non-water jump steeplechase barrier, 2) differences in step lengths between the four non-water jump barriers, and 3) changes in the step lengths around the barrier throughout the race. The step lengths around the 28 non-water jump barriers of the top seven men and women at the 2003 USA Track and Field Championships were measured using a two-dimensional analysis. A t-test determined any differences between men and women for the ratio of the landing to penultimate steps. A 2x4 repeated measures ANOVA tested for differences between the four non-water jump barriers. Linear regression tested for changes in step lengths throughout the race. Men exhibited a smaller ratio between the lengths of the landing to penultimate steps than women (0.73 ± 0.09 and 0.77 ± 0.10 for men and women respectively, p = 0.002). No step length differences were observed between the four barriers in the step lengths around each barrier (p = 0.192 and p = 0.105 for men and women respectively). Athletes gradually increased the total length of all steps around the barriers throughout the race (R(2) = 0.021, p = 0.048 and R(2) = 0.137, p < 0.001 for men and women respectively). The smaller ratio between landing to penultimate steps shows that the barriers affect women less than men. There may be a need to train men and women differently for the non-water jump barriers in the steeplechase or slightly alter racing strategy. Key PointsNon-water jump barriers disrupt the stride of men more than women.There is no difference between any of the four non-water jump barriers in the step lengths used around each barrier.Stride length gradually increases throughout a 3000m steeplechase race even if race pace is maintain.

Anticipatory kinematics and muscle activity preceding transitions from level-ground walking to stair ascent and descent.

PubMed

Peng, Joshua; Fey, Nicholas P; Kuiken, Todd A; Hargrove, Levi J

2016-02-29

The majority of fall-related accidents are during stair ambulation-occurring commonly at the top and bottom stairs of each flight, locations in which individuals are transitioning to stairs. Little is known about how individuals adjust their biomechanics in anticipation of walking-stair transitions. We identified the anticipatory stride mechanics of nine able-bodied individuals as they approached transitions from level ground walking to stair ascent and descent. Unlike prior investigations of stair ambulation, we analyzed two consecutive "anticipation" strides preceding the transitions strides to stairs, and tested a comprehensive set of kinematic and electromyographic (EMG) data from both the leading and trailing legs. Subjects completed ten trials of baseline overground walking and ten trials of walking to stair ascent and descent. Deviations relative to baseline were assessed. Significant changes in mechanics and EMG occurred in the earliest anticipation strides analyzed for both ascent and descent transitions. For stair descent, these changes were consistent with observed reductions in walking speed, which occurred in all anticipation strides tested. For stair ascent, subjects maintained their speed until the swing phase of the latest anticipation stride, and changes were found that would normally be observed for decreasing speed. Given the timing and nature of the observed changes, this study has implications for enhancing intent recognition systems and evaluating fall-prone or disabled individuals, by testing their abilities to sense upcoming transitions and decelerate during locomotion. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of subjective knee-joint pain on the laterality of knee extension strength and gait in elderly women.

PubMed

Sugiura, Hiroki; Demura, Shinichi

2012-01-01

This study aimed to examine the effect of subjective knee-joint pain on the laterality of knee extension strength and gait in elderly women. The subjects were 144 elderly women (62-94 years old; mean age 76.2±6.0 years; ±S.D.) who were divided into the following groups: 81 persons without knee-pain (no knee-pain group), 39 persons with the subjective pain in right or left knee (single knee-pain group), and 24 persons with the subjective pain in both knees (double knee-pain group). The subjects took a knee extension strength test and a 12 m maximum effort walk test. Knee extension strength, stance time, swing time, stride length, step length and swing speed were selected as parameters. A significant laterality was found in knee extension strength only in the one knee-pain group. The laterality of gait parameters was not found in all groups. In conclusion, elderly women who can perform daily living activity independently, even though having subjective pain in either knee or laterality in knee extension strength exertion show little laterality of gait during short distance walking. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Effect of stride frequency on thermoregulatory responses during endurance running in distance runners.

PubMed

Amano, Tatsuro; Ishitobi, Masaki; Ogura, Yukio; Inoue, Yoshimitsu; Koga, Shunsaku; Nishiyasu, Takeshi; Kondo, Narihiko

2016-10-01

Changing stride frequency may influence oxygen uptake and heart rate during running as a function of running economy and central command. This study investigated the influence of stride frequency manipulation on thermoregulatory responses during endurance running. Seven healthy endurance runners ran on a treadmill at a velocity of 15km/h for 60min in a controlled environmental chamber (ambient temperature 27°C and relative humidity 50%), and stride frequency was manipulated. Stride frequency was intermittently manipulated by increasing and decreasing frequency by 10% from the pre-determined preferred frequency. These periods of increase or decrease were separated by free frequency running in the order of free stride frequency, stride frequency manipulation (increase or decrease), free stride frequency, and stride frequency manipulation (increase or decrease) for 15min each. The increased and decreased stride frequencies were 110% and 91% of the free running frequency, respectively (196±6, 162±5, and 178±5steps/min, respectively, P<0.01). Compared to the control, stride frequency manipulation did not affect rectal temperature, heart rate, or the rate of perceived exhaustion during running. Whole-body sweat loss increased significantly when stride frequency was manipulated (1.48±0.11 and 1.57±0.11kg for control and manipulated stride frequencies, respectively, P<0.05), but stride frequency had a small effect on sweat loss overall (Cohen's d=0.31). A higher mean skin temperature was also observed under mixed frequency conditions compared to that in the control (P<0.05). While the precise mechanisms underlying these changes remain unknown (e.g. running economy or central command), our results suggest that manipulation of stride frequency does not have a large effect on sweat loss or other physiological variables, but does increase mean skin temperature during endurance running. Copyright © 2016. Published by Elsevier Ltd.

Impact of stance phase microprocessor-controlled knee prosthesis on ramp negotiation and community walking function in K2 level transfemoral amputees.

PubMed

Burnfield, Judith M; Eberly, Valerie J; Gronely, Joanne K; Perry, Jacquelin; Yule, William Jared; Mulroy, Sara J

2012-03-01

Microprocessor controlled prosthetic knees (MPK) offer opportunities for improved walking stability and function, but some devices' swing phase features may exceed needs of users with invariable cadence. One MPK offers computerized control of only stance (C-Leg Compact). To assess Medicare Functional Classification Level K2 walkers' ramp negotiation performance, function and balance while using a non-MPK (NMPK) compared to the C-Leg Compact. Crossover. Gait while ascending and descending a ramp (stride characteristics, kinematics, electromyography) and function were assessed in participant's existing NMPK and again in the C-Leg Compact following accommodation. Ramp ascent and descent were markedly faster in the C-Leg Compact compared to the NMPK (p ≤ 0.006), owing to increases in stride length (p ≤ 0.020) and cadence (p ≤ 0.020). Residual limb peak knee flexion and ankle dorsiflexion were significantly greater (12.9° and 4.9° more, respectively) during single limb support while using the C-Leg Compact to descend ramps. Electromyography (mean, peak) did not differ significantly between prosthesis. Function improved in the C-Leg Compact as evidenced by a significantly faster Timed Up and Go and higher functional questionnaire scores. Transfemoral K2 walkers exhibited significantly improved function and balance while using the stance-phase only MPK compared to their traditional NMPK.

Effect of balneotherapy on temporospatial gait characteristics of patients with osteoarthritis of the knee.

PubMed

Kiliçoğlu, Onder; Dönmez, Arif; Karagülle, Zeki; Erdoğan, Nergis; Akalan, Ekin; Temelli, Yener

2010-04-01

Effects of balneotherapy on gait properties of patients with osteoarthritis of the knee were investigated prospectively. A total of 30 patients with knee osteoarthritis received balneotherapy consisting of two daily thermomineral water baths for 2 weeks. Patients were evaluated using gait analysis and clinical scores, both within 2 weeks, before and after spa treatment. Patients were walking faster in their control analyses (0.81 +/- 0.21 to 0.89 +/- 0.19 m/s; P = 0.017), with a shorter mean stance time (63.0 +/- 3.3 to 61.8 +/- 2.5% stride; P = 0.007), an increased cadence (96 +/- 13.1 to 100 +/- 11.9 steps/min; P = 0.094) and stride length (996 +/- 174 to 1,058 +/- 142 mm; P = 0.017). Balneotherapy also resulted in a significant decrease in Lequesne knee osteoarthritis index (12.1 +/- 3.7 to 10.0 +/- 3.3 points; P = 0.003), VAS for pain (58 +/- 25 to 33 +/- 15; P = 0.0001), VAS for patients' (56 +/- 24 to 29 +/- 19; P < 0.001) and investigator's global assessment (55 +/- 20 to 26 +/- 15; P < 0.0001) and WOMAC score (2.1 +/- 0.7 to 1.6 +/- 0.8; P = 0.0004). Balneotherapy has positive effects on gait properties and clinical health quality parameters of patients with knee osteoarthritis in short-term evaluations.

Effects of Aging on Arm Swing during Gait: The Role of Gait Speed and Dual Tasking.

PubMed

Mirelman, Anat; Bernad-Elazari, Hagar; Nobel, Tomer; Thaler, Avner; Peruzzi, Agnese; Plotnik, Meir; Giladi, Nir; Hausdorff, Jeffrey M

2015-01-01

Healthy walking is characterized by pronounced arm swing and axial rotation. Aging effects on gait speed, stride length and stride time variability have been previously reported, however, less is known about aging effects on arm swing and axial rotation and their relationship to age-associated gait changes during usual walking and during more challenging conditions like dual tasking. Sixty healthy adults between the ages of 30-77 were included in this study designed to address this gap. Lightweight body fixed sensors were placed on each wrist and lower back. Participants walked under 3 walking conditions each of 1 minute: 1) comfortable speed, 2) walking while serially subtracting 3's (Dual Task), 3) walking at fast speed. Aging effects on arm swing amplitude, range, symmetry, jerk and axial rotation amplitude and jerk were compared between decades of age (30-40; 41-50; 51-60; 61-77 years). As expected, older adults walked slower (p = 0.03) and with increased stride variability (p = 0.02). Arm swing amplitude decreased with age under all conditions (p = 0.04). In the oldest group, arm swing decreased during dual task and increased during the fast walking condition (p<0.0001). Similarly, arm swing asymmetry increased during the dual task in the older groups (p<0.004), but not in the younger groups (p = 0.67). Significant differences between groups and within conditions were observed in arm swing jerk (p<0.02), axial rotation amplitude (p<0.02) and axial jerk (p<0.001). Gait speed, arm swing amplitude of the dominant arm, arm swing asymmetry and axial rotation jerk were all independent predictors of age in a multivariate model. These findings suggest that the effects of gait speed and dual tasking on arm swing and axial rotation during walking are altered among healthy older adults. Follow-up work is needed to examine if these effects contribute to reduced stability in aging.

Effects of Aging on Arm Swing during Gait: The Role of Gait Speed and Dual Tasking

PubMed Central

Mirelman, Anat; Bernad-Elazari, Hagar; Nobel, Tomer; Thaler, Avner; Peruzzi, Agnese; Plotnik, Meir; Giladi, Nir; Hausdorff, Jeffrey M.

2015-01-01

Healthy walking is characterized by pronounced arm swing and axial rotation. Aging effects on gait speed, stride length and stride time variability have been previously reported, however, less is known about aging effects on arm swing and axial rotation and their relationship to age-associated gait changes during usual walking and during more challenging conditions like dual tasking. Sixty healthy adults between the ages of 30–77 were included in this study designed to address this gap. Lightweight body fixed sensors were placed on each wrist and lower back. Participants walked under 3 walking conditions each of 1 minute: 1) comfortable speed, 2) walking while serially subtracting 3’s (Dual Task), 3) walking at fast speed. Aging effects on arm swing amplitude, range, symmetry, jerk and axial rotation amplitude and jerk were compared between decades of age (30–40; 41–50; 51–60; 61–77 years). As expected, older adults walked slower (p = 0.03) and with increased stride variability (p = 0.02). Arm swing amplitude decreased with age under all conditions (p = 0.04). In the oldest group, arm swing decreased during dual task and increased during the fast walking condition (p<0.0001). Similarly, arm swing asymmetry increased during the dual task in the older groups (p<0.004), but not in the younger groups (p = 0.67). Significant differences between groups and within conditions were observed in arm swing jerk (p<0.02), axial rotation amplitude (p<0.02) and axial jerk (p<0.001). Gait speed, arm swing amplitude of the dominant arm, arm swing asymmetry and axial rotation jerk were all independent predictors of age in a multivariate model. These findings suggest that the effects of gait speed and dual tasking on arm swing and axial rotation during walking are altered among healthy older adults. Follow-up work is needed to examine if these effects contribute to reduced stability in aging. PMID:26305896

Comparative analysis of human gait while wearing thong-style flip-flops versus sneakers.

PubMed

Shroyer, Justin F; Weimar, Wendi H

2010-01-01

Flip-flops are becoming a common footwear option. Casual observation has indicated that individuals wear flip-flops beyond their structural limit and have a different gait while wearing flip-flops versus shoes. This alteration in gait may cause the anecdotal foot and lower-limb discomfort associated with wearing flip-flops. To investigate the effect of sneakers versus thong-style flip-flops on gait kinematics and kinetics, 56 individuals (37 women and 19 men) were randomly assigned to a footwear order (flip-flops or sneakers first) and were asked to wear the assigned footwear on the day before and the day of testing. On each testing day, participants were videotaped as they walked at a self-selected pace across a force platform. A 2 (sex) x 2 (footwear) repeated-measures analysis of variance (P = .05) was used for statistical analysis. Significant interaction effects of footwear and sex were found for maximal anterior force, attack angle, and ankle angle during the swing phase. Footwear significantly affected stride length, ankle angle at the beginning of double support and during the swing phase, maximal braking impulse, and stance time. Flip-flops resulted in a shorter stride, a larger ankle angle at the beginning of double support and during the swing phase, a smaller braking impulse, and a shorter stance time compared with sneakers. The effects of footwear on gait kinetics and kinematics is extensive, but there is limited research on the effect of thong-style flip-flops on gait. These results suggest that flip-flops have an effect on several kinetic and kinematic variables compared with sneakers.

Six Weeks Habituation of Simulated Barefoot Running Induces Neuromuscular Adaptations and Changes in Foot Strike Patterns in Female Runners

PubMed Central

Khowailed, Iman Akef; Petrofsky, Jerrold; Lohman, Everett; Daher, Noha

2015-01-01

Background The aim of this study was to examine the effects of a 6-week training program of simulated barefoot running (SBR) on running kinetics in habitually shod (wearing shoes) female recreational runners. Material/Methods Twelve female runners age 25.7±3.4 years gradually increased running distance in Vibram FiveFingers minimal shoes over a 6-week period. The kinetic analysis of treadmill running at 10 Km/h was performed pre- and post-intervention in shod running, non-habituated SBR, and habituated SBR conditions. Spatiotemporal parameters, ground reaction force components, and electromyography (EMG) were measured in all conditions. Results Post-intervention data indicated a significant decrease across time in the habituation SBR for EMG activity of the tibialis anterior (TA) in the pre-activation and absorptive phase of running (P<0.001). A significant increase was denoted in the pre-activation amplitude of the gastrocnemius (GAS) between the shod running, unhabituated SBR, and habituated SBR. Six weeks of SBR was associated with a significant decrease in the loading rates and impact forces. Additionally, SBR significantly decrease the stride length, step duration, and flight time, and stride frequency was significantly higher compared to shod running. Conclusions The findings of this study indicate that changes in motor patterns in previously habitually shod runners are possible and can be accomplished within 6 weeks. Non-habituation SBR did not show a significant neuromuscular adaptation in the EMG activity of TA and GAS as manifested after 6 weeks of habituated SBR. PMID:26166443

An attempt to detect lameness in galloping horses by use of body-mounted inertial sensors.

PubMed

Lopes, Marco A F; Dearo, Antonio C O; Lee, Allen; Reed, Shannon K; Kramer, Joanne; Pai, P Frank; Yonezawa, Yoshiharu; Maki, Hiromitchi; Morgan, Terry L; Wilson, David A; Keegan, Kevin G

2016-10-01

OBJECTIVE To evaluate head, pelvic, and limb movement to detect lameness in galloping horses. ANIMALS 12 Thoroughbreds. PROCEDURES Movement data were collected with inertial sensors mounted on the head, pelvis, and limbs of horses trotting and galloping in a straight line before and after induction of forelimb and hind limb lameness by use of sole pressure. Successful induction of lameness was determined by measurement of asymmetric vertical head and pelvic movement during trotting. Differences in gallop strides before and after induction of lameness were evaluated with paired-sample statistical analysis and neural network training and testing. Variables included maximum, minimum, range, and time indices of vertical head and pelvic acceleration, head rotation in the sagittal plane, pelvic rotation in the frontal plane, limb contact intervals, stride durations, and limb lead preference. Difference between median standardized gallop strides for each limb lead before and after induction of lameness was calculated as the sum of squared differences at each time index and assessed with a 2-way ANOVA. RESULTS Head and pelvic acceleration and rotation, limb timing, stride duration measurements, and limb lead preference during galloping were not significantly different before and after induction of lameness in the forelimb or hind limb. Differences between limb leads before induction of lameness were similar to or greater than differences within limb leads before and after lameness induction. CONCLUSIONS AND CLINICAL RELEVANCE Galloping horses maintained asymmetry of head, pelvic, and limb motion between limb leads that was unrelated to lameness.

Fractal analyses reveal independent complexity and predictability of gait

PubMed Central

Dierick, Frédéric; Nivard, Anne-Laure

2017-01-01

Locomotion is a natural task that has been assessed for decades and used as a proxy to highlight impairments of various origins. So far, most studies adopted classical linear analyses of spatio-temporal gait parameters. Here, we use more advanced, yet not less practical, non-linear techniques to analyse gait time series of healthy subjects. We aimed at finding more sensitive indexes related to spatio-temporal gait parameters than those previously used, with the hope to better identify abnormal locomotion. We analysed large-scale stride interval time series and mean step width in 34 participants while altering walking direction (forward vs. backward walking) and with or without galvanic vestibular stimulation. The Hurst exponent α and the Minkowski fractal dimension D were computed and interpreted as indexes expressing predictability and complexity of stride interval time series, respectively. These holistic indexes can easily be interpreted in the framework of optimal movement complexity. We show that α and D accurately capture stride interval changes in function of the experimental condition. Walking forward exhibited maximal complexity (D) and hence, adaptability. In contrast, walking backward and/or stimulation of the vestibular system decreased D. Furthermore, walking backward increased predictability (α) through a more stereotyped pattern of the stride interval and galvanic vestibular stimulation reduced predictability. The present study demonstrates the complementary power of the Hurst exponent and the fractal dimension to improve walking classification. Our developments may have immediate applications in rehabilitation, diagnosis, and classification procedures. PMID:29182659

Lower limb mechanics during moderate high-heel jogging and running in different experienced wearers.

PubMed

Fu, Fengqin; Zhang, Yan; Shu, Yang; Ruan, Guoqing; Sun, Jianjun; Baker, Julien S; Gu, Yaodong

2016-08-01

The aim of this study is to investigate the differences in lower limb kinematics and kinetics between experienced (EW) and inexperienced (IEW) moderate high-heel wearers during jogging and running. Eleven experienced female wearers of moderate high-heel shoes and eleven matched controls participated in jogging and running tests. A Vicon motion analysis system was used to capture kinematic data and a Kistler force platform was used to collect ground reaction force (GRF). There were no significant differences in jogging and running speed respectively. Compared with IEW, EW adopted larger stride length (SL) with lower stride frequency (SF) at each corresponding speed. During running, EW enlarged SL significantly while IEW increased both SL and SF significantly. Kinematic data showed that IEW had generally larger joint range of motion (ROM) and peak angles during stance phase. Speed effect was not obvious within IEW. EW exhibited a significantly increased maximal vertical GRF (Fz2) and vertical average loading rate (VALR) during running, which was potentially caused by overlong stride. These suggest that both EW and IEW are at high risk of joint injuries when running on moderate high heels. For wearers who have to do some running on moderate high heels, it is crucial to control joint stability and balance SL and SF consciously. Copyright © 2016 Elsevier B.V. All rights reserved.

Passive in-home measurement of stride-to-stride gait variability comparing vision and Kinect sensing.

PubMed

Stone, Erik E; Skubic, Marjorie

2011-01-01

We present an analysis of measuring stride-to-stride gait variability passively, in a home setting using two vision based monitoring techniques: anonymized video data from a system of two web-cameras, and depth imagery from a single Microsoft Kinect. Millions of older adults fall every year. The ability to assess the fall risk of elderly individuals is essential to allowing them to continue living safely in independent settings as they age. Studies have shown that measures of stride-to-stride gait variability are predictive of falls in older adults. For this analysis, a set of participants were asked to perform a number of short walks while being monitored by the two vision based systems, along with a marker based Vicon motion capture system for ground truth. Measures of stride-to-stride gait variability were computed using each of the systems and compared against those obtained from the Vicon.

The Applicability of Rhythm-Motor Tasks to a New Dual Task Paradigm for Older Adults

PubMed Central

Kim, Soo Ji; Cho, Sung-Rae; Yoo, Ga Eul

2017-01-01

Given the interplay between cognitive and motor functions during walking, cognitive demands required during gait have been investigated with regard to dual task performance. Along with the needs to understand how the type of concurrent task while walking affects gait performance, there are calls for diversified dual tasks that can be applied to older adults with varying levels of cognitive decline. Therefore, this study aimed to examine how rhythm-motor tasks affect dual task performance and gait control, compared to a traditional cognitive-motor task. Also, it examined whether rhythm-motor tasks are correlated with traditional cognitive-motor task performance and cognitive measures. Eighteen older adults without cognitive impairment participated in this study. Each participant was instructed to walk at self-paced tempo without performing a concurrent task (single walking task) and walk while separately performing two types of concurrent tasks: rhythm-motor and cognitive-motor tasks. Rhythm-motor tasks included instrument playing (WalkIP), matching to rhythmic cueing (WalkRC), and instrument playing while matching to rhythmic cueing (WalkIP+RC). The cognitive-motor task involved counting forward by 3s (WalkCount.f3). In each condition, dual task costs (DTC), a measure for how dual tasks affect gait parameters, were measured in terms of walking speed and stride length. The ratio of stride length to walking speed, a measure for dynamic control of gait, was also examined. The results of this study demonstrated that the task type was found to significantly influence these measures. Rhythm-motor tasks were found to interfere with gait parameters to a lesser extent than the cognitive-motor task (WalkCount.f3). In terms of ratio measures, stride length remained at a similar level, walking speed greatly decreased in the WalkCount.f3 condition. Significant correlations between dual task-related measures during rhythm-motor and cognitive-motor tasks support the potential of applying rhythm-motor tasks to dual task methodology. This study presents how rhythm-motor tasks demand cognitive control at different levels than those engaged by cognitive-motor tasks. It also indicates how these new dual tasks can effectively mediate dual task performance indicative of fall risks, while requiring increased cognitive resources but facilitating gait control as a compensatory strategy to maintain gait stability. PMID:29375462

Limbic and Basal Ganglia Neuroanatomical Correlates of Gait and Executive Function: Older Adults With Mild Cognitive Impairment and Intact Cognition.

PubMed

McGough, Ellen L; Kelly, Valerie E; Weaver, Kurt E; Logsdon, Rebecca G; McCurry, Susan M; Pike, Kenneth C; Grabowski, Thomas J; Teri, Linda

2018-04-01

This study aimed to examine differences in spatiotemporal gait parameters between older adults with amnestic mild cognitive impairment and normal cognition and to examine limbic and basal ganglia neural correlates of gait and executive function in older adults without dementia. This was a cross-sectional study of 46 community-dwelling older adults, ages 70-95 yrs, with amnestic mild cognitive impairment (n = 23) and normal cognition (n = 23). Structural magnetic resonance imaging was used to attain volumetric measures of limbic and basal ganglia structures. Quantitative motion analysis was used to measure spatiotemporal parameters of gait. The Trail Making Test was used to assess executive function. During fast-paced walking, older adults with amnestic mild cognitive impairment demonstrated significantly slower gait speed and shorter stride length compared with older adults with normal cognition. Stride length was positively correlated with hippocampal, anterior cingulate, and nucleus accumbens volumes (P < 0.05). Executive function was positively correlated with hippocampal, anterior cingulate, and posterior cingulate volumes (P < 0.05). Compared with older adults with normal cognition, those with amnestic mild cognitive impairment demonstrated slower gait speed and shorter stride length, during fast-paced walking, and lower executive function. Hippocampal and anterior cingulate volumes demonstrated moderate positive correlation with both gait and executive function, after adjusting for age. Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME CME OBJECTIVES: Upon completion of this article, the reader should be able to: (1) discuss gait performance and cognitive function in older adults with amnestic mild cognitive impairment versus normal cognition, (2) discuss neurocorrelates of gait and executive function in older adults without dementia, and (3) recognize the importance of assessing gait speed and cognitive function in the clinical management of older adults at risk for dementia. Advanced ACCREDITATION: The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.The Association of Academic Physiatrists designates this Journal-based CME activity for a maximum of 0.5 AMA PRA Category 1 Credit(s)™. Physicians should only claim credit commensurate with the extent of their participation in the activity.

Estimating cardiorespiratory fitness in well-functioning older adults: treadmill validation of the long distance corridor walk.

PubMed

Simonsick, Eleanor M; Fan, Ellen; Fleg, Jerome L

2006-01-01

To determine criterion validity of the 400-m walk component of the Long Distance Corridor Walk (LDCW) and develop equations for estimating peak oxygen consumption (VO2) from 400-m time and factors intrinsic to test performance (e.g., heart rate (HR) and systolic blood pressure (SBP) response) in older adults. Cross-sectional validation study. Gerontology Research Center, National Institute on Aging, Baltimore, Maryland. Healthy volunteers (56 men and 46 women) aged 60 to 91 participating in the Baltimore Longitudinal Study of Aging between August 1999 and July 2000. The LDCW, consisting of a 2-minute walk followed immediately by a 400-m walk "done as quickly as possible" over a 20-m course was administered the day after maximal treadmill testing. HR and SBP were measured before testing and at the end of the 400-m walk. Weight, height, activity level, perceived effort, and stride length were also acquired. Peak VO2 ranged from 12.2 to 31.1 mL oxygen/kg per minute, and 400-m time ranged from 2 minutes 52 seconds to 6 minutes 18 seconds. Correlation between 400-m time and peak VO2 was -0.79. The estimating equation from linear regression included 400-m time (partial coefficient of determination (R2)=0.625), long versus short stride (partial R2=0.090), ending SBP (partial R2=0.019), and a correction factor for fast 400-m time (<240 seconds; partial R2=0.020) and explained 75.5% of the variance in peak VO2 (correlation coefficient=0.87). A 400-m walk performed as part of the LDCW provides a valid estimate of peak VO2 in older adults. Incorporating low-cost, safe assessments of fitness in clinical and research settings can identify early evidence of physical decline and individuals who may benefit from therapeutic interventions.

Reliability and validity of pressure and temporal parameters recorded using a pressure-sensitive insole during running.

PubMed

Mann, Robert; Malisoux, Laurent; Brunner, Roman; Gette, Paul; Urhausen, Axel; Statham, Andrew; Meijer, Kenneth; Theisen, Daniel

2014-01-01

Running biomechanics has received increasing interest in recent literature on running-related injuries, calling for new, portable methods for large-scale measurements. Our aims were to define running strike pattern based on output of a new pressure-sensitive measurement device, the Runalyser, and to test its validity regarding temporal parameters describing running gait. Furthermore, reliability of the Runalyser measurements was evaluated, as well as its ability to discriminate different running styles. Thirty-one healthy participants (30.3 ± 7.4 years, 1.78 ± 0.10 m and 74.1 ± 12.1 kg) were involved in the different study parts. Eleven participants were instructed to use a rearfoot (RFS), midfoot (MFS) and forefoot (FFS) strike pattern while running on a treadmill. Strike pattern was subsequently defined using a linear regression (R(2)=0.89) between foot strike angle, as determined by motion analysis (1000 Hz), and strike index (SI, point of contact on the foot sole, as a percentage of foot sole length), as measured by the Runalyser. MFS was defined by the 95% confidence interval of the intercept (SI=43.9-49.1%). High agreement (overall mean difference 1.2%) was found between stance time, flight time, stride time and duty factor as determined by the Runalyser and a force-measuring treadmill (n=16 participants). Measurements of the two devices were highly correlated (R ≥ 0.80) and not significantly different. Test-retest intra-class correlation coefficients for all parameters were ≥ 0.94 (n=14 participants). Significant differences (p<0.05) between FFS, RFS and habitual running were detected regarding SI, stance time and stride time (n=24 participants). The Runalyser is suitable for, and easily applicable in large-scale studies on running biomechanics. Copyright © 2013 Elsevier B.V. All rights reserved.

The influence of parachute-resisted sprinting on running mechanics in collegiate track athletes.

PubMed

Paulson, Sally; Braun, William A

2011-06-01

The influence of parachute-resisted sprinting on running mechanics in collegiate track athletes. The aim of this investigation was to compare the acute effects of parachute-resisted (PR) sprinting on selected kinematic variables. Twelve collegiate sprinters (mean age 19.58 ± 1.44 years, mass 69.32 ± 14.38 kg, height 1.71 ± 9.86 m) ran a 40-yd dash under 2 conditions: PR sprint and sprint without a parachute (NC) that were recorded on a video computer system (60 Hz). Sagittal plane kinematics of the right side of the body was digitized to calculate joint angles at initial ground contact (IGC) and end ground contact (EGC), ground contact (GC) time, stride rate (SR), stride length (SL), and the times of the 40-yd dashes. The NC 40-yd dash time was significantly faster than the PR trial (p < 0.05). The shoulder angle at EGC significantly increased from 34.10 to 42.10° during the PR trial (p < 0.05). There were no significant differences in GC time, SR, SL, or the other joint angles between the 2 trials (p > 0.05). This study suggests that PR sprinting does not acutely affect GC time, SR, SL and upper extremity or lower extremity joint angles during weight acceptance (IGC) in collegiate sprinters. However, PR sprinting increased shoulder flexion by 23.5% at push-off and decreased speed by 4.4%. While sprinting with the parachute, the athlete's movement patterns resembled their mechanics during the unloaded condition. This indicates the external load caused by PR did not substantially overload the runner, and only caused a minor change in the shoulder during push-off. This sports-specific training apparatus may provide coaches with another method for training athletes in a sports-specific manner without causing acute changes to running mechanics.

Hyperactivity in the Gunn rat model of neonatal jaundice: age-related attenuation and emergence of gait deficits

PubMed Central

Stanford, John A.; Shuler, Jeffrey M.; Fowler, Stephen C.; Stanford, Kimberly G.; Ma, Delin; Bittel, Douglas C.; Le Pichon, Jean-Baptiste; Shapiro, Steven M.

2014-01-01

Background Neonatal jaundice resulting from elevated unconjugated bilirubin (UCB) occurs in 60–80% of newborn infants. Although mild jaundice is generally considered harmless, little is known about its long-term consequences. Recent studies have linked mild bilirubin-induced neurological dysfunction (BIND) with a range of neurological syndromes, including attention deficit-hyperactivity disorder. The goal of this study was to measure BIND across the lifespan in the Gunn rat model of BIND. Methods Using a sensitive force plate actometer, we measured locomotor activity and gait in jaundiced (jj) Gunn rats versus their non-jaundiced (Nj) littermates. Data were analyzed for young adult (3–4 months), early middle-aged (9–10 months), and late middle-aged (17–20 months) male rats. Results jj rats exhibited lower body weights at all ages and a hyperactivity that resolved at 17–20 months of age. Increased propulsive force and gait velocity accompanied hyperactivity during locomotor bouts at 9–10 months in jj rats. Stride length did not differ between the two groups at this age. Hyperactivity normalized and gait deficits, including decreased stride length, propulsive force, and gait velocity, emerged in the 17–20-month-old jj rats. Conclusions These results demonstrate that, in aging, hyperactivity decreases with the onset of gait deficits in the Gunn rat model of BIND. PMID:25518009

The Effect of the Accelerometer Operating Range on Biomechanical Parameters: Stride Length, Velocity, and Peak Tibial Acceleration during Running

PubMed Central

Kiesewetter, Pierre; Milani, Thomas L.

2018-01-01

Previous studies have used accelerometers with various operating ranges (ORs) when measuring biomechanical parameters. However, it is still unclear whether ORs influence the accuracy of running parameters, and whether the different stiffnesses of footwear midsoles influence this accuracy. The purpose of the present study was to systematically investigate the influence of OR on the accuracy of stride length, running velocity, and on peak tibial acceleration. Twenty-one recreational heel strike runners ran on a 15-m indoor track at self-selected running speeds in three footwear conditions (low to high midsole stiffness). Runners were equipped with an inertial measurement unit (IMU) affixed to the heel cup of the right shoe and with a uniaxial accelerometer at the right tibia. Accelerometers (at the tibia and included in the IMU) with a high OR of ±70 g were used as the reference and the data were cut at ±32, ±16, and at ±8 g in post-processing, before calculating parameters. The results show that the OR influenced the outcomes of all investigated parameters, which were not influenced by tested footwear conditions. The lower ORs were associated with an underestimation error for all biomechanical parameters, which increased noticeably with a decreasing OR. It can be concluded that accelerometers with a minimum OR of ±32 g should be used to avoid inaccurate measurements. PMID:29303986

Fourier-based integration of quasi-periodic gait accelerations for drift-free displacement estimation using inertial sensors.

PubMed

Sabatini, Angelo Maria; Ligorio, Gabriele; Mannini, Andrea

2015-11-23

In biomechanical studies Optical Motion Capture Systems (OMCS) are considered the gold standard for determining the orientation and the position (pose) of an object in a global reference frame. However, the use of OMCS can be difficult, which has prompted research on alternative sensing technologies, such as body-worn inertial sensors. We developed a drift-free method to estimate the three-dimensional (3D) displacement of a body part during cyclical motions using body-worn inertial sensors. We performed the Fourier analysis of the stride-by-stride estimates of the linear acceleration, which were obtained by transposing the specific forces measured by the tri-axial accelerometer into the global frame using a quaternion-based orientation estimation algorithm and detecting when each stride began using a gait-segmentation algorithm. The time integration was performed analytically using the Fourier series coefficients; the inverse Fourier series was then taken for reconstructing the displacement over each single stride. The displacement traces were concatenated and spline-interpolated to obtain the entire trace. The method was applied to estimate the motion of the lower trunk of healthy subjects that walked on a treadmill and it was validated using OMCS reference 3D displacement data; different approaches were tested for transposing the measured specific force into the global frame, segmenting the gait and performing time integration (numerically and analytically). The width of the limits of agreements were computed between each tested method and the OMCS reference method for each anatomical direction: Medio-Lateral (ML), VerTical (VT) and Antero-Posterior (AP); using the proposed method, it was observed that the vertical component of displacement (VT) was within ±4 mm (±1.96 standard deviation) of OMCS data and each component of horizontal displacement (ML and AP) was within ±9 mm of OMCS data. Fourier harmonic analysis was applied to model stride-by-stride linear accelerations during walking and to perform their analytical integration. Our results showed that analytical integration based on Fourier series coefficients was a useful approach to accurately estimate 3D displacement from noisy acceleration data.

Biologically-variable rhythmic auditory cues are superior to isochronous cues in fostering natural gait variability in Parkinson's disease.

PubMed

Dotov, D G; Bayard, S; Cochen de Cock, V; Geny, C; Driss, V; Garrigue, G; Bardy, B; Dalla Bella, S

2017-01-01

Rhythmic auditory cueing improves certain gait symptoms of Parkinson's disease (PD). Cues are typically stimuli or beats with a fixed inter-beat interval. We show that isochronous cueing has an unwanted side-effect in that it exacerbates one of the motor symptoms characteristic of advanced PD. Whereas the parameters of the stride cycle of healthy walkers and early patients possess a persistent correlation in time, or long-range correlation (LRC), isochronous cueing renders stride-to-stride variability random. Random stride cycle variability is also associated with reduced gait stability and lack of flexibility. To investigate how to prevent patients from acquiring a random stride cycle pattern, we tested rhythmic cueing which mimics the properties of variability found in healthy gait (biological variability). PD patients (n=19) and age-matched healthy participants (n=19) walked with three rhythmic cueing stimuli: isochronous, with random variability, and with biological variability (LRC). Synchronization was not instructed. The persistent correlation in gait was preserved only with stimuli with biological variability, equally for patients and controls (p's<0.05). In contrast, cueing with isochronous or randomly varying inter-stimulus/beat intervals removed the LRC in the stride cycle. Notably, the individual's tendency to synchronize steps with beats determined the amount of negative effects of isochronous and random cues (p's<0.05) but not the positive effect of biological variability. Stimulus variability and patients' propensity to synchronize play a critical role in fostering healthier gait dynamics during cueing. The beneficial effects of biological variability provide useful guidelines for improving existing cueing treatments. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of rhythmic auditory cueing on gait in people with Alzheimer disease.

PubMed

Wittwer, Joanne E; Webster, Kate E; Hill, Keith

2013-04-01

To determine whether rhythmic music and metronome cues alter spatiotemporal gait measures and gait variability in people with Alzheimer disease (AD). A repeated-measures study requiring participants to walk under different cueing conditions. University movement laboratory. Of the people (N=46) who met study criteria (a diagnosis of probable AD and ability to walk 100m) at routine medical review, 30 (16 men; mean age ± SD, 80±6y; revised Addenbrooke's Cognitive Examination range, 26-79) volunteered to participate. Participants walked 4 times over an electronic walkway synchronizing to (1) rhythmic music and (2) a metronome set at individual mean baseline comfortable speed cadence. Gait spatiotemporal measures and gait variability (coefficient of variation [CV]). Data from individual walks under each condition were combined. A 1-way repeated-measures analysis of variance was used to compare uncued baseline, cued, and retest measures. Gait velocity decreased with both music and metronome cues compared with baseline (baseline, 110.5cm/s; music, 103.4cm/s; metronome, 105.4cm/s), primarily because of significant decreases in stride length (baseline, 120.9cm; music, 112.5cm; metronome, 114.8cm) with both cue types. This was coupled with increased stride length variability compared with baseline (baseline CV, 3.4%; music CV, 4.3%; metronome CV, 4.5%) with both cue types. These changes did not persist at (uncued) retest. Temporal variability was unchanged. Rhythmic auditory cueing at comfortable speed tempo produced deleterious effects on gait in a single session in this group with AD. The deterioration in spatial gait parameters may result from impaired executive function associated with AD. Further research should investigate whether these instantaneous cue effects are altered with more practice or with learning methods tailored to people with cognitive impairment. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Mechanical Alterations during 800-m Self-Paced Track Running.

PubMed

Girard, Olivier; Millet, Gregoire P; Micallef, Jean-Paul

2017-04-01

We assessed the time course of running mechanical alterations during an 800-m. On a 200-m indoor track, 18 physical education students performed an 800-m self-paced run. Once per lap, ground reaction forces were measured by a 5-m-long force platform system, and used to determine running kinetics/kinematics and spring-mass characteristics. Compared with 100 m (19.4±1.8 km.h -1 ) running velocity progressively decreased at 300, 500 m but levelled-off at 700 m marks (-5.7±4.6, -10.4±8.3, and -9.1±13.5%, respectively; P<0.001). Stride length (-8.5±2.3%, P<0.01) and frequency (-1.0±1.5%, P=0.05) along with peak braking (-7.5±4.4%, P<0.05) and push-off forces (-5.1±7.2%, P<0.05) decreased from 100 m to 700 m. Peak vertical forces (-3.0±2.7%; P>0.05) and leg compression (+2.8±3.9%; P>0.05) remained unchanged, whereas centre of mass vertical displacement (+24.0±7.0%; P<0.001) increased during the run. Vertical stiffness decreased (-18.1±4.4%; P<0.001), whereas leg stiffness was unchanged (-3.2±4.6%; P>0.05). During an 800 m by physical education students, highest running velocity was achieved early during the run, with a progressive decrease in the second half of the trial. While vertical ground force characteristics remained unchanged, non-specialist runners produced lower peak braking and push-off forces, in turn leading to shorter stride length. Spring-mass model characteristics changed toward lower vertical stiffness values, whereas leg stiffness did not change. © Georg Thieme Verlag KG Stuttgart · New York.

Development of Parkinson Patient Generated Data Collection Platform Using FHIR and IoT Devices.

PubMed

Kim, Dae-Young; Hwang, Sun-Ho; Kim, Min-Gyu; Song, Joon-Hyun; Lee, Sin-Woong; Kim, Il Kon

2017-01-01

Internet of Things (IoT) devices can be effectively used in cases where continuous observation of patients is required, such as Parkinson's disease. This is due to the characteristics of the IoT (Internet of Things), which allows data to be measured and transmitted at any time, anywhere. In this study, we developed a health data collection platform that stores and transmits the foot pressure data of Parkinson patients using FHIR (Fast Healthcare Interoperability Resources). The platform can be used to collect the foot pressure of a large number of Parkinson's patients. Based on the accumulated data, it is possible to identify abnormal behaviors such as walking pattern, tilt and instability of stride length in patients with Parkinson's disease. Based on the results of this study, accurate diagnosis and treatment of Parkinson's disease can be made.

Impact of a stance phase microprocessor-controlled knee prosthesis on level walking in lower functioning individuals with a transfemoral amputation.

PubMed

Eberly, Valerie J; Mulroy, Sara J; Gronley, JoAnne K; Perry, Jacquelin; Yule, William J; Burnfield, Judith M

2014-12-01

For individuals with transfemoral amputation, walking with a prosthesis presents challenges to stability and increases the demand on the hip of the prosthetic limb. Increasing age or comorbidities magnify these challenges. Computerized prosthetic knee joints improve stability and efficiency of gait, but are seldom prescribed for less physically capable walkers who may benefit from them. To compare level walking function while wearing a microprocessor-controlled knee (C-Leg Compact) prosthesis to a traditionally prescribed non-microprocessor-controlled knee prosthesis for Medicare Functional Classification Level K-2 walkers. Crossover. Stride characteristics, kinematics, kinetics, and electromyographic activity were recorded in 10 participants while walking with non-microprocessor-controlled knee and Compact prostheses. Walking with the Compact produced significant increase in velocity, cadence, stride length, single-limb support, and heel-rise timing compared to walking with the non-microprocessor-controlled knee prosthesis. Hip and thigh extension during late stance improved bilaterally. Ankle dorsiflexion, knee extension, and hip flexion moments of the prosthetic limb were significantly improved. Improvements in walking function and stability on the prosthetic limb were demonstrated by the K-2 level walkers when using the C-Leg Compact prosthesis. Understanding the impact of new prosthetic designs on gait mechanics is essential to improve prescription guidelines for deconditioned or older persons with transfemoral amputation. Prosthetic designs that improve stability for safety and walking function have the potential to improve community participation and quality of life. © The International Society for Prosthetics and Orthotics 2013.

Effect of normal-walking-pattern-based functional electrical stimulation on gait of the lower extremity in subjects with ischemic stroke: A self controlled study.

PubMed

Xu, Benlei; Yan, Tiebin; Yang, Yuanle; Ou, Ruiqing; Huang, Shuping

2016-01-01

Functional electrical stimulation is a widely used technique for rehabilitation. To assess the efficacy of walking-pattern-based four-channel functional electric stimulation and its influence on the gait features of stroke patients with hemiplegia. A total of 21 stroke patients with hemiplegia were enrolled into the study. The walking gaits of patients were investigated before, during and after walking-pattern-based FES treatment using the gait analysis system. The changes of gait indexes were comparatively analyzed. After walking-pattern-based FES therapy, the pace, stride rate, gait cycle, and step length of stroke patients with hemiplegia were 50.19 ± 14.45 cm/s, 36.85 ± 5.85 time/min, 1.6643 ± 0.2626 sec, 80.3333 ± 15.1438 cm, respectively. The motion range of hip and knee joint were 47.5238 ± 10.7453, 56.7619 ± 14.5255, respectively. We found these indexes were significantly improved compared with those before FES treatment (P <  0.05). The single swing rate (injured extremity/uninjured extremity) after FES treatment was 1.5589 ± 0.4550. The statistical results showed that the gait cycle, pace, stride rat, and single swing rate (injured extremity/uninjured extremity) were significantly improved after FES treatment (P <  0.05). Our results demonstrate that walking-paradigm based FES we developed is effective for treating stroke patients during rehabilitation.

Multimodal exercise intervention improves frontal cognitive functions and gait in Alzheimer's disease: a controlled trial.

PubMed

Coelho, Flávia Gomes de Melo; Andrade, Larissa Pires; Pedroso, Renata Valle; Santos-Galduroz, Ruth Ferreira; Gobbi, Sebastião; Costa, José Luiz Riani; Gobbi, Lilian Teresa Bucken

2013-01-01

The objective of the present study was to investigate the effect of a multimodal exercise intervention on frontal cognitive functions and kinematic gait parameters in patients with Alzheimer's disease. A sample of elderly patients with Alzheimer's disease (n=27) were assigned to a training group (n=14; aged 78.0±7.3 years) and a control group (n=13; aged 77.1±7.4 years). Multimodal exercise intervention includes motor activities and cognitive tasks simultaneously. The participants attended a 1-h session three times a week for 16 weeks, and the control participants maintained their regular daily activities during the same period. The frontal cognitive functions were evaluated using the Frontal Assessment Battery, the Clock Drawing Test and the Symbol Search Subtest. The kinematic parameters of gait-cadence, stride length and stride speed were analyzed under two conditions: (i) free gait (single task); and (ii) gait with frontal cognitive task (walking and counting down from 20--dual task). The patients in the intervention group significantly increased the scores in frontal cognitive variables, Frontal Assessment Battery (P<0.001) and Symbol Search Subtest (P<0.001) after the 16-week period. The control group decreased the scores in the Clock Drawing Test (P=0.001) and increased the number of counting errors during the dual task (P=0.008) after the same period. The multimodal exercise intervention improved the frontal cognitive functions in patients with Alzheimer's disease. © 2012 Japan Geriatrics Society.

Analysis of gait in rats with olivocerebellar lesions and ability of the nicotinic acetylcholine receptor agonist varenicline to attenuate impairments.

PubMed

Lambert, C S; Philpot, R M; Engberg, M E; Johns, B E; Wecker, L

2015-09-15

Studies have demonstrated that administration of the neuronal nicotinic receptor agonist varenicline to rats with olivocerebellar lesions attenuates balance deficits on a rotorod and balance beam, but the effects of this drug on gait deficits have not been investigated. To accomplish this, male Sprague-Dawley rats were trained to walk on a motorized treadmill at 25 and 35 cm/s and baseline performance determined; both temporal and spatial gait parameters were analyzed. A principal component analysis (PCA) was used to identify the key components of gait, and the cumulative gait index (CGI) was calculated, representing deviations from prototypical gait patterns. Subsequently, animals either remained as non-lesioned controls or received injections of 3-acetylpyridine (3-AP)/nicotinamide to destroy the climbing fibers innervating Purkinje cells. The gait of the non-lesioned group was assessed weekly to monitor changes in the normal population, while the gait of the lesioned group was assessed 1 week following 3-AP administration, and weekly following the daily administration of saline or varenicline (0.3, 1.0, or 3.0mg free base/kg) for 2 weeks. Non-lesioned animals exhibited a 60-70% increased CGI over time due to increases in temporal gait measures, whereas lesioned animals exhibited a nearly 3-fold increased CGI as a consequence of increases in spatial measures. Following 2 weeks of treatment with the highest dose of varenicline (3.0mg free base/kg), the swing duration of lesioned animals normalized, and stride duration, stride length and step angle in this population did not differ from the non-lesioned population. Thus, varenicline enabled animals to compensate for their impairments and rectify the timing of the gait cycle. Copyright © 2015 Elsevier B.V. All rights reserved.

Evaluation of joint findings with gait analysis in children with hemophilia.

PubMed

Cayir, Atilla; Yavuzer, Gunes; Sayli, Revide Tülin; Gurcay, Eda; Culha, Vildan; Bozkurt, Murat

2014-01-01

Hemophilic arthropathy due to recurrent joint bleeding leads to physical, psychological and socioeconomic problems in children with hemophilia and reduces their quality of life. The purpose of this study was to evaluate joint damage through various parameters and to determine functional deterioration in the musculoskeletal system during walking using kinetic and kinematic gait analysis. Physical examination and kinetic and kinematic gait analysis findings of 19 hemophilic patients aged 7-20 years were compared with those of age, sex and leg length matched controls. Stride time was longer in the hemophilia group (p=0.001) compared to the age matched healthy control group, while hip, knee and ankle joint rotation angles were more limited (p=0.001, p=0.035 and p=0.001, respectively). In the hemophilia group, the extensor moment of the knee joint in the stance phase was less than that in the control group (p=0.001). Stride time was longer in the severe hemophilia group compared to the mild-moderate hemophilia and control groups (p=0.011 and p=0.001, respectively). Rotation angle of the ankle was wider in the control group compared to the other two groups (p=0.001 for both). Rotation angle of the ankle joint was narrower in the severe hemophilia group compared to the others (p=0.001 for each). Extensor moment of the knee joint was greater in the control group compared to the other two groups (p=0.003 and p=0.001, respectively). Walking velocity was higher in the control group compared to the severe hemophilia group. Kinetic and kinematic gait analysis has the sensitivity to detect minimal changes in biomechanical parameters. Gait analysis can be used as a reliable method to detect early joint damage.

Human ethology: age and sex differences in mall walking.

PubMed

Hangland, A; Cimbalo, R S

1997-12-01

Well-controlled experimental research has examined the biomechanical aspects of walking in homo sapiens on a track. The research reported here also examined cadence, velocity, and stride length for estimated ages ranging from 15 to over 55 years but in a shopping mall. Women at all ages walked faster than men in the mall setting which was opposite to what was found in the track research. Apparently context may influence how fast people walk. Hunter-gatherer differences could explain these results.

A Mobile Kalman-Filter Based Solution for the Real-Time Estimation of Spatio-Temporal Gait Parameters.

PubMed

Ferrari, Alberto; Ginis, Pieter; Hardegger, Michael; Casamassima, Filippo; Rocchi, Laura; Chiari, Lorenzo

2016-07-01

Gait impairments are among the most disabling symptoms in several musculoskeletal and neurological conditions, severely limiting personal autonomy. Wearable gait sensors have been attracting attention as diagnostic tool for gait and are emerging as promising tool for tutoring and guiding gait execution. If their popularity is continuously growing, still there is room for improvement, especially towards more accurate solutions for spatio-temporal gait parameters estimation. We present an implementation of a zero-velocity-update gait analysis system based on a Kalman filter and off-the-shelf shoe-worn inertial sensors. The algorithms for gait events and step length estimation were specifically designed to comply with pathological gait patterns. More so, an Android app was deployed to support fully wearable and stand-alone real-time gait analysis. Twelve healthy subjects were enrolled to preliminarily tune the algorithms; afterwards sixteen persons with Parkinson's disease were enrolled for a validation study. Over the 1314 strides collected on patients at three different speeds, the total root mean square difference on step length estimation between this system and a gold standard was 2.9%. This shows that the proposed method allows for an accurate gait analysis and paves the way to a new generation of mobile devices usable anywhere for monitoring and intervention.

Gait characteristics after gait-oriented rehabilitation in chronic stroke.

PubMed

Peurala, Sinikka H; Titianova, Ekaterina B; Mateev, Plamen; Pitkänen, Kauko; Sivenius, Juhani; Tarkka, Ina M

2005-01-01

To assess the effects of rehabilitation in thirty-seven ambulatory patients with chronic stroke during three weeks in-patient rehabilitation period. In the intervention group, each patient received 75 min physiotherapy daily every workday including 20 minutes in the electromechanical gait trainer with body-weight support (BWS). In the control group, each patient participated in 45 min conventional physiotherapy daily. Motor ability was assessed with the first five items of the Modified Motor Assessment Scale (MMAS1-5) and ten meters walking speed. Spatio-temporal gait characteristics were recorded with an electrical walkway. The MMAS1-5 (p<0.0005 and p=0.005) and ten meters walking time (p<0.0005 and p=0.006) improved in both groups. The improvements in MMAS1-5 and ten meters walking time did not differ between the groups (p=0.217 and p=0.195). Specific gait characteristics improved only in the intervention group, as seen in increased Functional Ambulation Profile score (p=0.023), velocity (p=0.023), the step lengths (affected side, p=0.011, non-affected side p=0.040), the stride lengths (p=0.018, p=0.006) and decreased step-time differential (p=0.043). Furthermore, all gait characteristics and other motor abilities remained in the discharge level at the six months in the intervention group. It appears that BWS training gives a long-lasting benefit in gait qualities even in chronic stroke patients.

Control of voluntary and optogenetically perturbed locomotion by spike rate and timing of neurons of the mouse cerebellar nuclei

PubMed Central

Sarnaik, Rashmi

2018-01-01

Neurons of the cerebellar nuclei (CbN), which generate cerebellar output, are inhibited by Purkinje cells. With extracellular recordings during voluntary locomotion in head-fixed mice, we tested how the rate and coherence of inhibition influence CbN cell firing and well-practiced movements. Firing rates of Purkinje and CbN cells were modulated systematically through the stride cycle (~200–300 ms). Optogenetically stimulating ChR2-expressing Purkinje cells with light steps or trains evoked either asynchronous or synchronous inhibition of CbN cells. Steps slowed CbN firing. Trains suppressed CbN cell firing less effectively, but consistently altered millisecond-scale spike timing. Steps or trains that perturbed stride-related modulation of CbN cell firing rates correlated well with irregularities of movement, suggesting that ongoing locomotion is sensitive to alterations in modulated CbN cell firing. Unperturbed locomotion continued more often during trains than steps, however, suggesting that stride-related modulation of CbN spiking is less readily disrupted by synchronous than asynchronous inhibition. PMID:29659351

Unilateral total hip replacement patients with symptomatic leg length inequality have abnormal hip biomechanics during walking.

PubMed

Li, Junyan; McWilliams, Anthony B; Jin, Zhongmin; Fisher, John; Stone, Martin H; Redmond, Anthony C; Stewart, Todd D

2015-06-01

Symptomatic leg length inequality accounts for 8.7% of total hip replacement related claims made against the UK National Health Service Litigation authority. It has not been established whether symptomatic leg length inequality patients following total hip replacement have abnormal hip kinetics during gait. Hip kinetics in 15 unilateral total hip replacement patients with symptomatic leg length inequality during gait was determined through multibody dynamics and compared to 15 native hip healthy controls and 15 'successful' asymptomatic unilateral total hip replacement patients. More significant differences from normal were found in symptomatic leg length inequality patients than in asymptomatic total hip replacement patients. The leg length inequality patients had altered functions defined by lower gait velocity, reduced stride length, reduced ground reaction force, decreased hip range of motion, reduced hip moment and less dynamic hip force with a 24% lower heel-strike peak, 66% higher mid-stance trough and 37% lower toe-off peak. Greater asymmetry in hip contact force was also observed in leg length inequality patients. These gait adaptions may affect the function of the implant and other healthy joints in symptomatic leg length inequality patients. This study provides important information for the musculoskeletal function and rehabilitation of symptomatic leg length inequality patients. Copyright © 2015. Published by Elsevier Ltd.

Virtual Reality as a Medium for Sensorimotor Adaptation Training and Spaceflight Countermeasures

NASA Technical Reports Server (NTRS)

Madansingh, S.; Bloomberg, J. J.

2014-01-01

Astronauts experience a profound sensorimotor adaptation during transition to and from the microgravity environment of space. With the upcoming shift to extra-long duration missions (upwards of 1 year) aboard the International Space Station, the immediate risks to astronauts during these transitory periods become more important than ever to understand and prepare for. Recent advances in virtual reality technology enable everyday adoption of these tools for entertainment and use in training. Embedding an individual in a virtual environment (VE) allows the ability to change the perception of visual flow, elicit automatic motor behavior and produce sensorimotor adaptation, not unlike those required during long duration microgravity exposure. The overall goal of this study is to determine the feasibility of present head mounted display technology (HMD) to produce reliable visual flow information and the expected adaptation associated with virtual environment manipulation to be used in future sensorimotor adaptability countermeasures. To further understand the influence of visual flow on gait adaptation during treadmill walking, a series of discordant visual flow manipulations in a virtual environment are proposed. Six healthy participants (3 male and 3 female) will observe visual flow information via HMD (Oculus Rift DK2) while walking on an instrumented treadmill at their preferred walking speed. Participants will be immersed in a series of VE's resembling infinite hallways with different visual characteristics: an office hallway, a hallway with pillars and the hallway of a fictional spacecraft. Participants will perform three trials of 10 min. each, which include walking on the treadmill while receiving congruent or incongruent visual information via the HMD. In the first trial, participants will experience congruent visual information (baseline) where the hallway is perceived to move at the same rate as their walking speed. The final two trials will be randomized among participants where the hallway is perceived to move at either half (0.5x) or twice (2.0x) their preferred walking speed. Participants will remain on the treadmill between trials and will not be warned of the upcoming change to visual flow to minimize preparatory adjustments. Stride length, step frequency and dual-support time will be quantified during each trial. We hypothesize that participants will experience a rapid modification in gait performance during periods of adaptive change, expressed as a decrease in step length, an increase in step frequency and an increase in dual-support time, followed by a period of adaptation where these movement parameters will return to near-baseline levels. As stride length, step frequency and dual support times return to baseline values, an adaptation time constant will be derived to establish individual time-to-adapt (TTA). HMD technology represents a paradigm shift in sensorimotor adaptation training where gait adaptability can be stressed using off-the-shelf consumer products and minimal experimental equipment, allowing for greater training flexibility in astronaut and terrestrial applications alike.

Dynamic markers of altered gait rhythm in amyotrophic lateral sclerosis

NASA Technical Reports Server (NTRS)

Hausdorff, J. M.; Lertratanakul, A.; Cudkowicz, M. E.; Peterson, A. L.; Kaliton, D.; Goldberger, A. L.

2000-01-01

Amyotrophic lateral sclerosis (ALS) is a disorder marked by loss of motoneurons. We hypothesized that subjects with ALS would have an altered gait rhythm, with an increase in both the magnitude of the stride-to-stride fluctuations and perturbations in the fluctuation dynamics. To test for this locomotor instability, we quantitatively compared the gait rhythm of subjects with ALS with that of normal controls and with that of subjects with Parkinson's disease (PD) and Huntington's disease (HD), pathologies of the basal ganglia. Subjects walked for 5 min at their usual pace wearing an ankle-worn recorder that enabled determination of the duration of each stride and of stride-to-stride fluctuations. We found that the gait of patients with ALS is less steady and more temporally disorganized compared with that of healthy controls. In addition, advanced ALS, HD, and PD were associated with certain common, as well as apparently distinct, features of altered stride dynamics. Thus stride-to-stride control of gait rhythm is apparently compromised with ALS. Moreover, a matrix of markers based on gait dynamics may be useful in characterizing certain pathologies of motor control and, possibly, in quantitatively monitoring disease progression and evaluating therapeutic interventions.

Exercise and Nutritional Supplementation on Community-Dwelling Elderly Japanese Women With Sarcopenic Obesity: A Randomized Controlled Trial.

PubMed

Kim, Hunkyung; Kim, Miji; Kojima, Narumi; Fujino, Ken; Hosoi, Erika; Kobayashi, Hisamine; Somekawa, Shinji; Niki, Yoshifumi; Yamashiro, Yukari; Yoshida, Hideyo

2016-11-01

To investigate the effects of exercise and/or nutritional supplementation on body composition, blood components, and physical function in community-dwelling elderly Japanese women with sarcopenic obesity. Randomized controlled trial. Urban community in Tokyo, Japan. Among 1213 community-dwelling elderly women over 70 years of age, 307 were defined with sarcopenic obesity, and 139 women participated in the study. Participants were randomly assigned to one of four intervention groups. The exercise and nutrition (Ex + N) and exercise only (Ex) groups attended 60-minute exercise classes twice a week for 3 months. The Ex + N and nutrition only (N) groups were provided with essential amino acid supplementation and tea fortified with catechins to be taken daily for 3 months. Health education classes were provided to the control (HE) group every 2 weeks. Bioelectric impedance analysis was used to measure body composition. Skeletal muscle mass index was calculated using measures of muscle mass and height. Physical function measures included grip strength, knee extension strength, usual walking speed, and walking parameters (stride, step length, width, walking angles). Blood samples were obtained to analyze levels of albumin, triglycerides, cholesterol, hemoglobin A1c, leptin, cystatin C, vitamin D, interleukin-6, and high-sensitivity C-reactive protein. Significant between-group × time interactions were observed in usual walking speed (P = .012), stride (P = .004), right step length (P = .003), average number of steps (P = .029), and vitamin D (P < .001). Compared to the HE group, the Ex + N intervention significantly decreased total body fat mass (P = .036) and increased stride (P = .038) and vitamin D (P < .001). Significant reductions in trunk fat were observed in the Ex group compared with HE (P = .014). The Ex + N and Ex interventions were over four times as likely (odds ratio [95% confidence interval]) to reduce body fat mass than the HE group (4.42 [1.21-16.19]; 4.50 [1.13-17.9], respectively). Significant odds ratios of the Ex + N intervention improving walking speed (3.05 [1.01-9.19]), vitamin D (14.22 [1.64-123.02]), and leptin (3.86 [1.19-12.47]) were also observed. Although exercise and nutrition have beneficial effects on individual variables of body composition, blood components, and physical function, improvements in muscle mass and variable combinations such as percent fat + skeletal muscle mass index or percent fat + physical functions were not observed in this population. Further large-scale and long-term investigation is necessary. Copyright © 2016 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

An Automatic Gait Feature Extraction Method for Identifying Gait Asymmetry Using Wearable Sensors

PubMed Central

Vassallo, Michael

2018-01-01

This paper aims to assess the use of Inertial Measurement Unit (IMU) sensors to identify gait asymmetry by extracting automatic gait features. We design and develop an android app to collect real time synchronous IMU data from legs. The results from our method are validated using a Qualisys Motion Capture System. The data are collected from 10 young and 10 older subjects. Each performed a trial in a straight corridor comprising 15 strides of normal walking, a turn around and another 15 strides. We analyse the data for total distance, total time, total velocity, stride, step, cadence, step ratio, stance, and swing. The accuracy of detecting the stride number using the proposed method is 100% for young and 92.67% for older subjects. The accuracy of estimating travelled distance using the proposed method for young subjects is 97.73% and 98.82% for right and left legs; and for the older, is 88.71% and 89.88% for right and left legs. The average travelled distance is 37.77 (95% CI ± 3.57) meters for young subjects and is 22.50 (95% CI ± 2.34) meters for older subjects. The average travelled time for young subjects is 51.85 (95% CI ± 3.08) seconds and for older subjects is 84.02 (95% CI ± 9.98) seconds. The results show that wearable sensors can be used for identifying gait asymmetry without the requirement and expense of an elaborate laboratory setup. This can serve as a tool in diagnosing gait abnormalities in individuals and opens the possibilities for home based self-gait asymmetry assessment. PMID:29495299

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bosler, Peter Andrew; Roesler, Erika Louise; Taylor, Mark A.

This article discusses the problem of identifying extreme climate events such as intense storms within large climate data sets. The basic storm detection algorithm is reviewed, which splits the problem into two parts: a spatial search followed by a temporal correlation problem. Two specific implementations of the spatial search algorithm are compared. The commonly used grid point search algorithm is reviewed, and a new algorithm called Stride Search is introduced. Stride Search is designed to work at all latitudes, while grid point searches may fail in polar regions. Results from the two algorithms are compared for the application of tropicalmore » cyclone detection, and shown to produce similar results for the same set of storm identification criteria. The time required for both algorithms to search the same data set is compared. Furthermore, Stride Search's ability to search extreme latitudes is demonstrated for the case of polar low detection.« less

Assessing Stride Variables and Vertical Stiffness with GPS-Embedded Accelerometers: Preliminary Insights for the Monitoring of Neuromuscular Fatigue on the Field

PubMed Central

Buchheit, Martin; Gray, Andrew; Morin, Jean-Benoit

2015-01-01

The aim of the present study was to examine the ability of a GPS-imbedded accelerometer to assess stride variables and vertical stiffness (K), which are directly related to neuromuscular fatigue during field-based high-intensity runs. The ability to detect stride imbalances was also examined. A team sport player performed a series of 30-s runs on an instrumented treadmill (6 runs at 10, 17 and 24 km·h-1) with or without his right ankle taped (aimed at creating a stride imbalance), while wearing on his back a commercially-available GPS unit with an embedded 100-Hz tri-axial accelerometer. Contact (CT) and flying (FT) time, and K were computed from both treadmill and accelerometers (Athletic Data Innovations) data. The agreement between treadmill (criterion measure) and accelerometer-derived data was examined. We also compared the ability of the different systems to detect the stride imbalance. Biases were small (CT and K) and moderate (FT). The typical error of the estimate was trivial (CT), small (K) and moderate (FT), with nearly perfect (CT and K) and large (FT) correlations for treadmill vs. accelerometer. The tape induced very large increase in the right - left foot ∆ in CT, FT and K measured by the treadmill. The tape effect on CT and K ∆ measured with the accelerometers were also very large, but of lower magnitude than with the treadmill. The tape effect on accelerometer-derived ∆ FT was unclear. Present data highlight the potential of a GPS-embedded accelerometer to assess CT and K during ground running. Key points GPS-embedded tri-axial accelerometers may be used to assess contact time and vertical stiffness during ground running. These preliminary results open new perspective for the field monitoring of neuromuscular fatigue and performance in run-based sports PMID:26664264

Frequency-velocity mismatch: a fundamental abnormality in parkinsonian gait.

PubMed

Cho, Catherine; Kunin, Mikhail; Kudo, Koji; Osaki, Yasuhiro; Olanow, C Warren; Cohen, Bernard; Raphan, Theodore

2010-03-01

Gait dysfunction and falling are major sources of disability for patients with advanced Parkinson's disease (PD). It is presently thought that the fundamental defect is an inability to generate normal stride length. Our data suggest, however, that the basic problem in PD gait is an impaired ability to match step frequency to walking velocity. In this study, foot movements of PD and normal subjects were monitored with an OPTOTRAK motion-detection system while they walked on a treadmill at different velocities. PD subjects were also paced with auditory stimuli at different frequencies. PD gait was characterized by step frequencies that were faster and stride lengths that were shorter than those of normal controls. At low walking velocities, PD stepping had a reduced or absent terminal toe lift, which truncated swing phases, producing shortened steps. Auditory pacing was not able to normalize step frequency at these lower velocities. Peak forward toe velocities increased with walking velocity and PD subjects could initiate appropriate foot dynamics during initial phases of the swing. They could not control the foot appropriately in terminal phases, however. Increased treadmill velocity, which matched the natural PD step frequency, generated a second toe lift, normalizing step size. Levodopa increased the bandwidth of step frequencies, but was not as effective as increases in walking velocity in normalizing gait. We postulate that the inability to control step frequency and adjust swing phase dynamics to slower walking velocities are major causes for the gait impairment in PD.

Frequency-Velocity Mismatch: A Fundamental Abnormality in Parkinsonian Gait

PubMed Central

Kunin, Mikhail; Kudo, Koji; Osaki, Yasuhiro; Olanow, C. Warren; Cohen, Bernard; Raphan, Theodore

2010-01-01

Gait dysfunction and falling are major sources of disability for patients with advanced Parkinson's disease (PD). It is presently thought that the fundamental defect is an inability to generate normal stride length. Our data suggest, however, that the basic problem in PD gait is an impaired ability to match step frequency to walking velocity. In this study, foot movements of PD and normal subjects were monitored with an OPTOTRAK motion-detection system while they walked on a treadmill at different velocities. PD subjects were also paced with auditory stimuli at different frequencies. PD gait was characterized by step frequencies that were faster and stride lengths that were shorter than those of normal controls. At low walking velocities, PD stepping had a reduced or absent terminal toe lift, which truncated swing phases, producing shortened steps. Auditory pacing was not able to normalize step frequency at these lower velocities. Peak forward toe velocities increased with walking velocity and PD subjects could initiate appropriate foot dynamics during initial phases of the swing. They could not control the foot appropriately in terminal phases, however. Increased treadmill velocity, which matched the natural PD step frequency, generated a second toe lift, normalizing step size. Levodopa increased the bandwidth of step frequencies, but was not as effective as increases in walking velocity in normalizing gait. We postulate that the inability to control step frequency and adjust swing phase dynamics to slower walking velocities are major causes for the gait impairment in PD. PMID:20042701

Lower extremity joint loads in habitual rearfoot and mid/forefoot strike runners with normal and shortened stride lengths.

PubMed

Boyer, Elizabeth R; Derrick, Timothy R

2018-03-01

Our purpose was to compare joint loads between habitual rearfoot (hRF) and habitual mid/forefoot strikers (hFF), rearfoot (RFS) and mid/forefoot strike (FFS) patterns, and shorter stride lengths (SLs). Thirty-eight hRF and hFF ran at their normal SL, 5% and 10% shorter, as well as with the opposite foot strike. Three-dimensional ankle, knee, patellofemoral (PF) and hip contact forces were calculated. Nearly all contact forces decreased with a shorter SL (1.2-14.9% relative to preferred SL). In general, hRF had higher PF (hRF-RFS: 10.8 ± 1.4, hFF-FFS: 9.9 ± 2.0 BWs) and hip loads (axial hRF-RFS: -9.9 ± 0.9, hFF-FFS: -9.6 ± 1.0 BWs) than hFF. Many loads were similar between foot strike styles for the two groups, including axial and lateral hip, PF, posterior knee and shear ankle contact forces. Lateral knee and posterior hip contact forces were greater for RFS, and axial ankle and knee contact forces were greater for FFS. The tibia may be under greater loading with a FFS because of these greater axial forces. Summarising, a particular foot strike style does not universally decrease joint contact forces. However, shortening one's SL 10% decreased nearly all lower extremity contact forces, so it may hold potential to decrease overuse injuries associated with excessive joint loads.

Efficacy of a hybrid assistive limb in post-stroke hemiplegic patients: a preliminary report

PubMed Central

2011-01-01

Background Robotic devices are expected to be widely used in various applications including support for the independent mobility of the elderly with muscle weakness and people with impaired motor function as well as support for nursing care that involves heavy laborious work. We evaluated the effects of a hybrid assistive limb robot suit on the gait of stroke patients undergoing rehabilitation. Methods The study group comprised 16 stroke patients with severe hemiplegia. All patients underwent gait training. Four patients required assistance, and 12 needed supervision while walking. The stride length, walking speed and physiological cost index on wearing the hybrid assistive limb suit and a knee-ankle-foot orthosis were compared. Results The hybrid assistive limb suit increased the stride length and walking speed in 4 of 16 patients. The patients whose walking speed decreased on wearing the hybrid assistive limb suit either had not received sufficient gait training or had an established gait pattern with a knee-ankle-foot orthosis using a quad cane. The physiological cost index increased after wearing the hybrid assistive limb suit in 12 patients, but removal of the suit led to a decrease in the physiological cost index values to equivalent levels prior to the use of the suit. Conclusions Although the hybrid assistive limb suit is not useful for all hemiplegic patients, it may increase the walking speed and affect the walking ability. Further investigation would clarify its indication for the possibility of gait training. PMID:21943320

Correlation between the Quality of Attention and Cognitive Competence with Motor Action in Stroke Patients.

PubMed

Arsic, S; Konstantinovic, Lj; Eminovic, F; Pavlovic, D; Popovic, M B; Arsic, V

2015-01-01

It is considered that cognitive function and attention could affect walking, motion control, and proper conduct during the walk. To determine whether there is a difference in the quality of attention and cognitive ability in stroke patients and patients without neurological damage of similar age and education and to determine whether the connection of attention and cognition affects motor skills, the sample consisted of 50 stroke patients tested with hemiparesis, involved in the process of rehabilitation, and 50 persons, randomly chosen, without neurological damage. The survey used the following tests: Trail Making (TMT A B) test for assessing the flexibility of attention; Mini-Mental State Examination (MMSE) for cognitive status; Functional Ambulation Category (FAC) test to assess the functional status and parameters of walk: speed, frequency, and length of stride; STEP test for assessing the precision of movement and balance. With stroke patients, relationship between age and performance on the MMSE test was marginally significant. The ratio of performance to TMT A B test and years does not indicate statistical significance, while statistical significance between the MMSE test performance and education exists. In stroke patients, performance on MMSE test is correlated with the frequency and length of stride walk. The quality of cognitive function and attention is associated with motor skills but differs in stroke patients and people without neurological damage of similar age. The significance of this correlation can supplement research in neurorehabilitation, improve the quality of medical rehabilitation, and contribute to efficient recovery of these patients.

Effect of Sacroiliac Joint Manipulation on Selected Gait Parameters in Healthy Subjects.

PubMed

Wójtowicz, Sebastian; Sajko, Igor; Hadamus, Anna; Mosiołek, Anna; Białoszewski, Dariusz

2017-08-31

The sacroiliac joints have complicated biomechanics. While the movements in the joints are small, they exert a significant effect on gait. This study aimed to assess how sacroiliac joint manipulation influences selected gait parameters. The study enrolled 57 healthy subjects. The experimental group consisted of 26 participants diagnosed with dysfunction of one sacroiliac joint. The control group was composed of 31 persons. All subjects from the experimental group underwent sacroiliac joint manipulation. The experimental group showed significant lengthening of the step on both sides and the stride length in this group increased as well. Moreover, the duration of the stride increased (p=0.000826). The maximum midfoot pressure was higher and maximum heel pressure decreased. The differences were statistically significant. 1. Subclinical dysfunctions of the sacroiliac joints may cause functional gait disturbance. 2. Manipulation of the iliosacral joint exerts a significant effect on gait parameters, which may lead to improved gait economy and effec-tiveness. 3. Following manipulation of one iliosacral joint, altered gait parameters are noted on both the manipulated side and the contralateral side, which may translate into improved quality of locomotion.

Influence of training on the biokinematics in trotting Andalusian horses.

PubMed

Cano, M R; Miró, F; Diz, A M; Agüera, E; Galisteo, A M

2000-11-01

The aim of this study was to determine the influence of a 10-month training programme on the linear, temporal and angular characteristics of the fore and hind limbs at the trot in the Andalusian horse, using standard computer-aided videography. Sixteen male Andalusian horses were observed before and after training. Six strides were randomly selected for analysis in each horse and linear, temporal and angular parameters were calculated for fore and hind limbs. The training programme used here produced significant changes in kinematic parameters, such as shortening of stride length, and increase in swing duration and a decrease in hind limb stance percentage. No significant differences were recorded in the angular values for the forelimb joints. In trained horses, the more proximal joints of the hind limb, especially the hip and stifle, had a greater flexion while the fetlock showed a smaller extension angle. At the beginning of the swing phase, hip and stifle joints presented angles that were significantly more flexed. When the hind limbs came into contact with the ground, all the joints presented greater flexion after training.

Gait as solution, but what is the problem? Exploring cost, economy and compromise in locomotion.

PubMed

Bertram, John E A

2013-12-01

Many studies have examined how legged mammals move, defining 'what' happens in locomotion. However, few ask 'why' those motions occur as they do. The energetic and functional constraints acting on an animal require that locomotion should be metabolically 'cost effective' and this in large part determines the strategies available to accomplish the task. Understanding the gaits utilised, within the spectrum of gaits possible, and determination of the value of specific relationships among speed, stride length, stride frequency and morphology, depends on identifying the fundamental costs involved and the effects of different movement strategies on those costs. It is argued here that a fundamental loss associated with moving on limbs (centre of mass momentum and energy loss) and two costs involved with controlling and replacing that loss (muscular work of the supporting limb during stance and muscular work of repositioning the limbs during swing) interact to determine the cost trade-offs involved and the optimisation strategies available for each species and speed. These optimisation strategies are what has been observed and characterised as gait. Copyright © 2013 Elsevier Ltd. All rights reserved.

Path tortuosity in everyday movements of elderly persons increases fall prediction beyond knowledge of fall history, medication use, and standardized gait and balance assessments.

PubMed

Kearns, William D; Fozard, James L; Becker, Marion; Jasiewicz, Jan M; Craighead, Jeffrey D; Holtsclaw, Lori; Dion, Charles

2012-09-01

We hypothesized that variability in voluntary movement paths of assisted living facility (ALF) residents would be greater in the week preceding a fall compared with residents who did not fall. Prospective, observational study using telesurveillance technology. Two ALFs. The sample consisted of 69 older ALF residents (53 female) aged 76.9 (SD ± 11.9 years). Daytime movement in ALF common use areas was automatically tracked using a commercially available ultra-wideband radio real-time location sensor network with a spatial resolution of approximately 20 cm. Movement path variability (tortuosity) was gauged using fractal dimension (fractal D). A logistic regression was performed predicting movement related falls from fractal D, presence of a fall in the prior year, psychoactive medication use, and movement path length. Fallers and non-fallers were also compared on activities of daily living requiring supervision or assistance, performance on standardized static and dynamic balance, and stride velocity assessments gathered at the start of a 1-year fall observation period. Fall risk due to cognitive deficit was assessed by the Mini Mental Status Examination (MMSE), and by clinical dementia diagnoses from participant's activities of daily living health record. Logistic regression analysis revealed odds of falling increased 2.548 (P = .021) for every 0.1 increase in fractal D, and having a fall in the prior year increased odds of falling by 7.36 (P = .006). There was a trend for longer movement paths to reduce the odds of falling (OR .976 P = .08) but it was not significant. Number of psychoactive medications did not contribute significantly to fall prediction in the model. Fallers had more variable stride-to-stride velocities and required more activities of daily living assistance. High fractal D levels can be detected using commercially available telesurveillance technologies and offers a new tool for health services administrators seeking to reduce falls at their facilities. Copyright © 2012 American Medical Directors Association. Published by Elsevier Inc. All rights reserved.

Muscle Activation Patterns in Infants with Myelomeningocele Stepping on a Treadmill

PubMed Central

Sansom, Jennifer K.; Teulier, Caroline; Smith, Beth A.; Moerchen, Victoria; Muraszko, Karin; Ulrich, Beverly D.

2013-01-01

Purpose To characterize how infants with myelomeningocele (MMC) activate lower limb muscles over the first year of life, without practice, while stepping on a motorized treadmill. Methods Twelve infants with MMC were tested longitudinally at 1, 6, 12 months. Electromyography (EMG) was used to collect data from the tibialis anterior (TA), lateral gastrocnemius (LG), rectus femoris (RF), biceps femoris (BF). Results Across the first year, infants showed no EMG activity for ~50% of the stride cycle w/poor rhythmicity and timing of muscles, when activated. Single muscle activation predominated; agonist-antagonist co-activation was low. Probability of individual muscle activity across the stride decreased w/age. Conclusions Infants with MMC show high variability in timing and duration of muscle activity, few complex combinations, and very little change over time. PMID:23685739

Effects of short-term repeated exposure to different flooring surfaces on the behavior and physiology of dairy cattle.

PubMed

Schütz, K E; Cox, N R

2014-05-01

Dairy cattle managed in some pasture-based systems such as in New Zealand are predominantly kept outdoors all year around, but are often taken off pasture for periods of time in wet weather to avoid soil damage. It is common to keep cattle on concrete surfaces during such "stand-off" practices and we investigated whether the addition of rubber matting onto concrete areas improves the welfare of dairy cattle. Sixteen groups of 5 cows (4 groups/treatment, 5 cows/group) were allocated to 1 of 4 treatments (concrete, 12-mm-thick rubber mat, 24-mm-thick rubber mat, or deep-bedded wood chips) and kept on these surfaces for 18 h/24h for 4 consecutive days (6h on pasture/24h). Each 4-d stand-off period was repeated 4 times (with 7 d of recovery between periods) to study the accumulated effects of repeated stand-off. Lying behavior was recorded continuously during the experiment. Gait score, stride length, hygiene score, live weight, and blood samples for cortisol analysis were recorded immediately before and after each stand-off period. Cows on wood chips spent the most time lying, and cows on concrete spent the least time lying compared with those on other surfaces [wood chips: 10.8h, 24-mm rubber mat: 7.3h, 12-mm rubber mat: 6.0 h, and concrete: 2.8h/18 h, standard error of the difference (SED): 0.71 h]. Cows on concrete spent more time lying during the 6h on pasture, likely compensating for the reduced lying during the stand-off period. Similarly, cows on concrete spent more time lying on pasture between stand-off periods (concrete: 12.1h, 12-mm rubber mat: 11.1h, 24-mm rubber mat: 11.2h, and wood chips: 10.7h/24h, SED: 0.28 h). Cows on concrete had higher gait score and shorter stride length after the 4-d stand-off period compared with cows on the other surface types, suggesting a change in gait pattern caused by discomfort. Cows on rubber mats were almost 3 times dirtier than cows on concrete or wood chips. Cortisol and live weight decreased for all treatment groups during the stand-off period. We observed no major effect of the repeated stand-off exposure. In summary, adding rubber matting onto concrete surfaces for stand-off purposes is beneficial for animal welfare. A well-managed wood chip surface offered the best welfare for dairy cows removed from pasture, and the findings of this study confirm that a concrete surface decreases the welfare of cows removed from pasture. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

History of visual systems in the Systems Engineering Simulator

NASA Technical Reports Server (NTRS)

Christianson, David C.

1989-01-01

The Systems Engineering Simulator (SES) houses a variety of real-time computer generated visual systems. The earliest machine dates from the mid-1960's and is one of the first real-time graphics systems in the world. The latest acquisition is the state-of-the-art Evans and Sutherland CT6. Between the span of time from the mid-1960's to the late 1980's, tremendous strides have been made in the real-time graphics world. These strides include advances in both software and hardware engineering. The purpose is to explore the history of the development of these real-time computer generated image systems from the first machine to the present. Hardware advances as well as software algorithm changes are presented. This history is not only quite interesting but also provides us with a perspective with which we can look backward and forward.

Walking efficiency before and after total hip replacement.

PubMed

Brown, M; Hislop, H J; Waters, R L; Porell, D

1980-10-01

The energy cost of walking and gait characteristics of patients with hip disease were studied to determine changes in walking efficiency following total hip replacement. Twenty-nine patients, 24 with unilateral hip disease and 5 with bilateral hip disease, were tested preoperatively and at various times postoperatively. Oxygen uptake was measured by a modified Douglas bag procedure. The temporal and distance characteristics of gait were measured with contact closing heel switches. Results showed postoperative increases in velocity, cadence, and stride length in patients with unilateral disease and with bilateral disease with bilateral replacement. After surgery, energy cost tended toward more normal levels, but the subjects were not within normal limits for oxygen uptake per minute, oxygen uptake per distance walked, or percent of predicted maximum aerobic capacity. Comparison of energy expenditure data with temporal and distance factors of gait indicated that all subjects became more physiologically efficient after hip replacement.

Does acupuncture ameliorate motor impairment after stroke? An assessment using the CatWalk gait system.

PubMed

Cao, Yan; Sun, Ning; Yang, Jing-Wen; Zheng, Yang; Zhu, Wen; Zhang, Zhen-Hua; Wang, Xue-Rui; Shi, Guang-Xia; Liu, Cun-Zhi

2017-07-01

The effect of acupuncture on gait deficits after stroke is uncertain. This animal study was designed to determine whether acupuncture improves gait impairment following experimentally induced ischemic stroke. Ischemic stroke was induced by permanent middle cerebral artery occlusion (MCAO) in rats. After 7 days' of acupuncture treatment, assessment of gait changes using the CatWalk automated gait analysis system was performed. Comparison of the CatWalk gait parameters among the groups showed that gait function was impaired after ischemic stroke and acupuncture treatment was effective in improving a variety of gait parameters including intensity, stance and swing time, swing speed and stride length at postoperative day 8. This study demonstrates a beneficial effect of acupuncture on gait impairment in rats following ischemic stroke. Further studies aimed to investigate the effects of acupuncture at different stages during stroke using the CatWalk system are required. Copyright © 2016 Elsevier Ltd. All rights reserved.

Falls prevention advice and visual feedback to those at risk of falling: study protocol for a pilot randomized controlled trial

PubMed Central

2013-01-01

Background Studies have shown that functional strength and balance exercises can reduce the risk of falling in older people if they are done on a regular basis. However, the repetitive nature of these exercises; combined with the inherent lack of feedback of progress may discourage seniors from exercising in the home, thereby rendering such an intervention ineffective. This study hypothesizes that the use of visual feedback and multimodal games will be more effective in encouraging adherence to home rehabilitation than standard care; thereby promoting independence and improving the quality of life in older adults at risk of falling. Methods A pllel-group pilot randomized controlled trial with 3 groups of participants will be conducted in the home for 12 weeks. Participants will include older adults who have been identified as at risk of falling (n = 48), over the age of 65, living in the community, and suitable for a home exercise intervention. The primary outcome is adherence to exercise. Secondary outcomes include: variability in stride length, stride time and double support time (DST); walking speed; Timed up and go test (TUG); Falls Efficacy Scale International (FES-I); CONFbal scale; Romberg’s test; and quality of life measures (SF-12 and EuroQol EQ-5D). Qualitative assessments on personal experiences with rehabilitation tools will be done before and after the trial. Discussion This study will investigate the use of visual feedback and engaging multimodal activities to address the problem of non-compliance to home exercises for falls rehabilitation. One of the unique qualities of this study is the adaptation of special participatory design methods through which the end users (fallers) will be involved in the design of the proposed rehabilitation tools at various stages of the design process. Trial registration ISRCTN79967470 PMID:23510162

Nonlinear time series analysis of normal and pathological human walking

NASA Astrophysics Data System (ADS)

Dingwell, Jonathan B.; Cusumano, Joseph P.

2000-12-01

Characterizing locomotor dynamics is essential for understanding the neuromuscular control of locomotion. In particular, quantifying dynamic stability during walking is important for assessing people who have a greater risk of falling. However, traditional biomechanical methods of defining stability have not quantified the resistance of the neuromuscular system to perturbations, suggesting that more precise definitions are required. For the present study, average maximum finite-time Lyapunov exponents were estimated to quantify the local dynamic stability of human walking kinematics. Local scaling exponents, defined as the local slopes of the correlation sum curves, were also calculated to quantify the local scaling structure of each embedded time series. Comparisons were made between overground and motorized treadmill walking in young healthy subjects and between diabetic neuropathic (NP) patients and healthy controls (CO) during overground walking. A modification of the method of surrogate data was developed to examine the stochastic nature of the fluctuations overlying the nominally periodic patterns in these data sets. Results demonstrated that having subjects walk on a motorized treadmill artificially stabilized their natural locomotor kinematics by small but statistically significant amounts. Furthermore, a paradox previously present in the biomechanical literature that resulted from mistakenly equating variability with dynamic stability was resolved. By slowing their self-selected walking speeds, NP patients adopted more locally stable gait patterns, even though they simultaneously exhibited greater kinematic variability than CO subjects. Additionally, the loss of peripheral sensation in NP patients was associated with statistically significant differences in the local scaling structure of their walking kinematics at those length scales where it was anticipated that sensory feedback would play the greatest role. Lastly, stride-to-stride fluctuations in the walking patterns of all three subject groups were clearly distinguishable from linearly autocorrelated Gaussian noise. As a collateral benefit of the methodological approach taken in this study, some of the first steps at characterizing the underlying structure of human locomotor dynamics have been taken. Implications for understanding the neuromuscular control of locomotion are discussed.

Walking-adaptability assessments with the Interactive Walkway: Between-systems agreement and sensitivity to task and subject variations.

PubMed

Geerse, Daphne J; Coolen, Bert H; Roerdink, Melvyn

2017-05-01

The ability to adapt walking to environmental circumstances is an important aspect of walking, yet difficult to assess. The Interactive Walkway was developed to assess walking adaptability by augmenting a multi-Kinect-v2 10-m walkway with gait-dependent visual context (stepping targets, obstacles) using real-time processed markerless full-body kinematics. In this study we determined Interactive Walkway's usability for walking-adaptability assessments in terms of between-systems agreement and sensitivity to task and subject variations. Under varying task constraints, 21 healthy subjects performed obstacle-avoidance, sudden-stops-and-starts and goal-directed-stepping tasks. Various continuous walking-adaptability outcome measures were concurrently determined with the Interactive Walkway and a gold-standard motion-registration system: available response time, obstacle-avoidance and sudden-stop margins, step length, stepping accuracy and walking speed. The same holds for dichotomous classifications of success and failure for obstacle-avoidance and sudden-stops tasks and performed short-stride versus long-stride obstacle-avoidance strategies. Continuous walking-adaptability outcome measures generally agreed well between systems (high intraclass correlation coefficients for absolute agreement, low biases and narrow limits of agreement) and were highly sensitive to task and subject variations. Success and failure ratings varied with available response times and obstacle types and agreed between systems for 85-96% of the trials while obstacle-avoidance strategies were always classified correctly. We conclude that Interactive Walkway walking-adaptability outcome measures are reliable and sensitive to task and subject variations, even in high-functioning subjects. We therefore deem Interactive Walkway walking-adaptability assessments usable for obtaining an objective and more task-specific examination of one's ability to walk, which may be feasible for both high-functioning and fragile populations since walking adaptability can be assessed at various levels of difficulty. Copyright © 2017 Elsevier B.V. All rights reserved.

Changes in gait while backward counting in demented older adults with frontal lobe dysfunction.

PubMed

Allali, Gilles; Kressig, Reto W; Assal, Frédéric; Herrmann, François R; Dubost, Véronique; Beauchet, Olivier

2007-10-01

Gait disorders caused by dementia have been associated with frontal lobe dysfunction. Dual-tasking is used to explore the involvement of cortical level in gait control. It has been shown that dual-task induced gait changes that could be related to (1) the efficiency of executive function, (2) the level of difficulty involved in the walking-associated task, or (3) the articulo-motor components comprised in the walking-associated task. A better understanding of dual-task related changes in demented subjects with frontal lobe dysfunction could help us to clarify the role of the frontal lobe in motor gait control. To assess and compare the effects of two mental arithmetic tasks involving similar articulo-motor components but different level of difficulty on the mean values and coefficient of variation (CV) of stride time among demented older adults with impaired executive function. The mean values and coefficients of variation of stride time were measured using a GAITRite-System among 16 demented older adults with impaired executive function while walking with and without forward counting (FC) and backward counting (BC). The mean values and CV of stride time were significantly higher under both dual-task conditions than during a simple walking task (p<0.05). The change in CV of stride time during BC was significantly higher when compared with the change during FC (p=0.015), whereas the change in mean value was not significant (p=0.056). There was no difference between the dual-task and single task condition as far the number of enumerated figures were concerned (p=0.678 for FC and p=0.069 for BC), but significantly fewer figures were enumerated while BC compared with FC (p<0.001). BC provoked more changes in gait parameters than FC with major modification in gait variability related to an inappropriate focusing of attention. These findings suggest that the CV may be a suitable criterion for the assessment of gait control.

Bobcat attack on a cottontail rabbit

USGS Publications Warehouse

Biggins, D.E.; Biggins, D.M.

2006-01-01

We observed an attack by a bobcat (Lynx rufus) on a cottontail rabbit (Sylvilagus) that involved stealthy approach by the cat for >1 h, followed by a 12.3-s chase covering 116.0 m for the cat and 128.4 m for the rabbit. During the chase, the route of the cat from starting point to kill site was more direct than the semi-circular route of the rabbit. Stride lengths for the cat and total distance covered by the chase were longer than those previously reported for bobcats.

Influence of dual task and frailty on gait parameters of older community-dwelling individuals

PubMed Central

Guedes, Rita C.; Dias, Rosângela C.; Pereira, Leani S. M.; Silva, Sílvia L. A.; Lustosa, Lygia P.; Dias, João M. D.

2014-01-01

Background: Gait parameters such as gait speed (GS) are important indicators of functional capacity. Frailty Syndrome is closely related to GS and is also capable of predicting adverse outcomes. The cognitive demand of gait control is usually explored with dual-task (DT) methodology. Objective: To investigate the effect of DT and frailty on the spatio-temporal parameters of gait in older people and identify which variables relate to GS. Method: The presence of frailty was verified by Fried's Frailty Criteria. Cognitive function was evaluated with the Mini-Mental State Exam (MMSE) and gait parameters were analyzed through the GAITRite(r) system in the single-task and DT conditions. The Kolmogorov-Smirnov, ANOVA, and Pearson's Correlation tests were administered. Results: The participants were assigned to the groups frail (FG), pre-frail (PFG), and non-frail (NFG). During the DT, the three groups showed a decrease in GS, cadence, and stride length and an increase in stride time (p<0.001). The reduction in the GS of the FG during the DT showed a positive correlation with the MMSE scores (r=730; p=0.001) and with grip strength (r=681; p=0.001). Conclusions: Gait parameters are more affected by the DT, especially in the frail older subjects. The reduction in GS in the FG is associated with lower grip strength and lower scores in the MMSE. The GS was able to discriminate the older adults in the three levels of frailty, being an important measure of the functional capacity in this population. PMID:25372007

Pre-clinical and clinical walking kinematics in female breeding pigs with lameness: A nested case-control cohort study.

PubMed

Stavrakakis, S; Guy, J H; Syranidis, I; Johnson, G R; Edwards, S A

2015-07-01

Gait profiles were investigated in a cohort of female pigs experiencing a lameness period prevalence of 29% over 17 months. Gait alterations before and during visually diagnosed lameness were evaluated to identify the best quantitative clinical lameness indicators and early predictors for lameness. Pre-breeding gilts (n= 84) were recruited to the study over a period of 6 months, underwent motion capture every 5 weeks and, depending on their age at entry to the study, were followed for up to three successive gestations. Animals were subject to motion capture in each parity at 8 weeks of gestation and on the day of weaning (28 days postpartum). During kinematic motion capture, the pigs walked on the same concrete walkway and an array of infra-red cameras was used to collect three dimensional coordinate data of reflective skin markers attached to the head, trunk and limb anatomical landmarks. Of 24 pigs diagnosed with lameness, 19 had preclinical gait records, whilst 18 had a motion capture while lame. Depending on availability, data from one or two preclinical motion capture 1-11 months prior to lameness and on the day of lameness were analysed. Lameness was best detected and evaluated using relative spatiotemporal gait parameters, especially vertical head displacement and asymmetric stride phase timing. Irregularity in the step-to-stride length ratio was elevated (deviation  ≥ 0.03) in young pigs which presented lameness in later life (odds ratio 7.2-10.8). Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of observation on lower limb prosthesis gait biomechanics: Preliminary results.

PubMed

Malchow, Connor; Fiedler, Goeran

2016-12-01

The Hawthorne effect, a subcategory of reactivity, causes human behavior to change when under observation. Such an effect may apply to gait variation of persons with prosthetics or orthotics devices. This study investigated whether the presence of observers directly affects the gait pattern of users of lower limb prostheses. Within-subject intervention study. Primary outcome measures were gait parameters of initial double support time and upper body lateral tilt angle, which were collected with a mobile sensor attached to the subjects' back. To make subjects feel unwatched, a certain amount of deception was necessary, and two different conditions were created and statistically compared against each other: one in which the subjects were initially unaware of the attention of observers and another one in which the same subjects were aware of a group of observers. Data from two subjects using trans-femoral prosthesis are reported. Findings included a change in step initial double support percentage by up to 14.2% (p = 0.019). Considerable changes were also noted in secondary outcome measures including speed, stride length, and stride symmetry. A reactivity effect of observation exists in prosthetics gait analysis. More comprehensive studies may be motivated by these preliminary findings. Results of this study suggest that users of lower limb prostheses walk differently when their gait is being assessed (e.g. in the prosthetist's office) than in situations without observers. This may in part explain the clinical experience that modifications of prosthetic fit or alignment provide only short-term betterment. © The International Society for Prosthetics and Orthotics 2015.

Association between daily walking and antioxidant capacity in patients with symptomatic peripheral artery disease.

PubMed

Gardner, Andrew W; Montgomery, Polly S; Zhao, Yan D; Silva-Palacios, Federico; Ungvari, Zoltan; Csiszar, Anna; Sonntag, William E

2017-06-01

The primary aim of the study was to assess whether both the amount and pace of daily walking were associated with circulating antioxidant capacity in symptomatic patients with peripheral artery disease (PAD). Community-based walking was measured in 244 men and women who were limited by symptomatic PAD during a 1-week period in which they wore an ankle-mounted step activity monitor. Patients were further characterized by circulating antioxidant capacity with the OxiSelect (Cell Biolabs Inc, San Diego, Calif) hydroxyl radical antioxidant capacity (HORAC) activity assay. To assess the amount of walking, patients were grouped into low (≤2440 strides/d), middle (2441-3835 strides/d), and high (>3835 strides/d) stride tertiles. HORAC was higher in the middle (P = .03) and high (P = .01) stride tertiles than in the low tertile, but there was no difference between middle and high tertiles (P = .44). To assess the pace of walking, patients were grouped into slow (<25.0 strides/min), middle (25.0-31.6 strides/min), and fast (>31.6 strides/min) cadence tertiles. HORAC was higher in the high cadence tertile than in the low (P < .01) and middle (P < .01) tertiles, but there was no difference between low and middle tertiles (P = .48). Similar findings were obtained on group differences in HORAC after adjusting for age, sex, race, and ankle-brachial index for both the amount and pace of daily walking. Walking >2440 strides each day and walking at a cadence faster than 31.6 strides/min for 30 minutes each day are both associated with greater circulating antioxidant capacity in symptomatic patients with PAD. The clinical significance is that a home-based walking program may be one approach to increase endogenous antioxidant capacity. Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Identifying Stride-To-Stride Control Strategies in Human Treadmill Walking

PubMed Central

Dingwell, Jonathan B.; Cusumano, Joseph P.

2015-01-01

Variability is ubiquitous in human movement, arising from internal and external noise, inherent biological redundancy, and from the neurophysiological control actions that help regulate movement fluctuations. Increased walking variability can lead to increased energetic cost and/or increased fall risk. Conversely, biological noise may be beneficial, even necessary, to enhance motor performance. Indeed, encouraging more variability actually facilitates greater improvements in some forms of locomotor rehabilitation. Thus, it is critical to identify the fundamental principles humans use to regulate stride-to-stride fluctuations in walking. This study sought to determine how humans regulate stride-to-stride fluctuations in stepping movements during treadmill walking. We developed computational models based on pre-defined goal functions to compare if subjects, from each stride to the next, tried to maintain the same speed as the treadmill, or instead stay in the same position on the treadmill. Both strategies predicted average behaviors empirically indistinguishable from each other and from that of humans. These strategies, however, predicted very different stride-to-stride fluctuation dynamics. Comparisons to experimental data showed that human stepping movements were generally well-predicted by the speed-control model, but not by the position-control model. Human subjects also exhibited no indications they corrected deviations in absolute position only intermittently: i.e., closer to the boundaries of the treadmill. Thus, humans clearly do not adopt a control strategy whose primary goal is to maintain some constant absolute position on the treadmill. Instead, humans appear to regulate their stepping movements in a way most consistent with a strategy whose primary goal is to try to maintain the same speed as the treadmill at each consecutive stride. These findings have important implications both for understanding how biological systems regulate walking in general and for being able to harness these mechanisms to develop more effective rehabilitation interventions to improve locomotor performance. PMID:25910253

Early rehabilitation treatment combined with equinovarus foot deformity surgical correction in stroke patients: safety and changes in gait parameters.

PubMed

Giannotti, Erika; Merlo, Andrea; Zerbinati, Paolo; Longhi, Maria; Prati, Paolo; Masiero, Stefano; Mazzoli, Davide

2016-06-01

Equinovarus foot deformity (EVFD) compromises several prerequisites of walking and increases the risk of falling. Guidelines on rehabilitation following EVFD surgery are missing in current literature. The aim of this study was to analyze safety and adherence to an early rehabilitation treatment characterized by immediate weight bearing with an ankle-foot orthosis (AFO) in hemiplegic patients after EVFD surgery and to describe gait changes after EVFD surgical correction combined with early rehabilitation treatment. Retrospective observational cohort study. Inpatient rehabilitation clinic. Forty-seven adult patients with hemiplegia consequent to ischemic or haemorrhagic stroke (L/R 20/27, age 56±15 years, time from lesion 6±5 years). A specific rehabilitation protocol with a non-articulated AFO, used to allow for immediate gait training, started one day after EVFD surgery. Gait analysis (GA) data before and one month after surgery were analyzed. The presence of differences in GA space-time parameters, in ankle dorsiflexion (DF) values and peaks at initial contact (DF at IC), during stance (DF at St) and swing (DF at Sw) were assessed by the Wilcoxon Test while the presence of correlations between pre- and post-operative values by Spearman's correlation coefficient. All patients completed the rehabilitation protocol and no clinical complications occurred in the sample. Ankle DF increased one month after surgery at all investigated gait phases (Wilcoxon Test, P<0.0001), becoming neutral at IC. Significant (P<0.05) variations were found for stride length, stride width, anterior step length of the affected side and for the duration of the double support phase of the contralateral side. The postsurgery ankle DF at St was found to be correlated (R=0.81, P<0.0001) with its pre-surgery value, thus being predictable. Weaker significant correlations were found for DF at Sw and DF at IC, where contribution from the dorsiflexor muscles is required in addition to calf muscle passive lengthening. An orthosis-assisted immediate rehabilitation associated with surgical procedure is safe and may be suitable to correct EVFD by restoring both the neutral heel foot-ground contact and the ankle DF peaks during stance and swing at one month from surgery. The proposed protocol is a safe and potentially useful rehabilitative approach after EVFD surgical correction in stroke patients.

Reducing the metabolic cost of walking with an ankle exoskeleton: interaction between actuation timing and power.

PubMed

Galle, Samuel; Malcolm, Philippe; Collins, Steven Hartley; De Clercq, Dirk

2017-04-27

Powered ankle-foot exoskeletons can reduce the metabolic cost of human walking to below normal levels, but optimal assistance properties remain unclear. The purpose of this study was to test the effects of different assistance timing and power characteristics in an experiment with a tethered ankle-foot exoskeleton. Ten healthy female subjects walked on a treadmill with bilateral ankle-foot exoskeletons in 10 different assistance conditions. Artificial pneumatic muscles assisted plantarflexion during ankle push-off using one of four actuation onset timings (36, 42, 48 and 54% of the stride) and three power levels (average positive exoskeleton power over a stride, summed for both legs, of 0.2, 0.4 and 0.5 W∙kg -1 ). We compared metabolic rate, kinematics and electromyography (EMG) between conditions. Optimal assistance was achieved with an onset of 42% stride and average power of 0.4 W∙kg -1 , leading to 21% reduction in metabolic cost compared to walking with the exoskeleton deactivated and 12% reduction compared to normal walking without the exoskeleton. With suboptimal timing or power, the exoskeleton still reduced metabolic cost, but substantially less so. The relationship between timing, power and metabolic rate was well-characterized by a two-dimensional quadratic function. The assistive mechanisms leading to these improvements included reducing muscular activity in the ankle plantarflexors and assisting leg swing initiation. These results emphasize the importance of optimizing exoskeleton actuation properties when assisting or augmenting human locomotion. Our optimal assistance onset timing and average power levels could be used for other exoskeletons to improve assistance and resulting benefits.

Harmony as a convergence attractor that minimizes the energy expenditure and variability in physiological gait and the loss of harmony in cerebellar ataxia.

PubMed

Serrao, Mariano; Chini, Giorgia; Iosa, Marco; Casali, Carlo; Morone, Giovanni; Conte, Carmela; Bini, Fabiano; Marinozzi, Franco; Coppola, Gianluca; Pierelli, Francesco; Draicchio, Francesco; Ranavolo, Alberto

2017-10-01

The harmony of the human gait was recently found to be related to the golden ratio value (ϕ). The ratio between the duration of the stance and that of the swing phases of a gait cycle was in fact found to be close to ϕ, which implies that, because of the fractal property of autosimilarity of that number, the gait ratios stride/stance, stance/swing, swing/double support, were not significantly different from one another. We studied a group of patients with cerebellar ataxia to investigate how the differences between their gait ratios and the golden ratio are related to efficiency and stability of their gait, assessed by energy expenditure and stride-to-stride variability, respectively. The gait of 28 patients who were affected by degenerative cerebellar ataxia and of 28 healthy controls was studied using a stereophotogrammetric system. The above mentioned gait ratios, the energy expenditure estimated using the pelvis reconstructed method and the gait variability in terms of the stride length were computed, and their relationships were analyzed. Matching procedures have also been used to avoid multicollinearity biases. The gait ratio values of the patients were farther from the controls (and hence from ϕ), even in speed matched conditions (P=0.011, Cohen's D=0.76), but not when the variability and energy expenditure were matched between the two groups (Cohen's D=0.49). In patients with cerebellar ataxia, the farther the stance-swing ratio was from ϕ, the larger the total mechanical work (R 2 adj =0.64). Further, a significant positive correlation was observed between the difference of the gait ratio from the golden ratio and the severity of the disease (R=0.421, P=0.026). Harmony of gait appears to be a benchmark of physiological gait leading to physiological energy recovery and gait reliability. Neurorehabilitation of patients with ataxia might benefit from the restoration of harmony of their locomotor patterns. Copyright © 2017. Published by Elsevier Ltd.

Gait parameter control timing with dynamic manual contact or visual cues

PubMed Central

Shi, Peter; Werner, William

2016-01-01

We investigated the timing of gait parameter changes (stride length, peak toe velocity, and double-, single-support, and complete step duration) to control gait speed. Eleven healthy participants adjusted their gait speed on a treadmill to maintain a constant distance between them and a fore-aft oscillating cue (a place on a conveyor belt surface). The experimental design balanced conditions of cue modality (vision: eyes-open; manual contact: eyes-closed while touching the cue); treadmill speed (0.2, 0.4, 0.85, and 1.3 m/s); and cue motion (none, ±10 cm at 0.09, 0.11, and 0.18 Hz). Correlation analyses revealed a number of temporal relationships between gait parameters and cue speed. The results suggest that neural control ranged from feedforward to feedback. Specifically, step length preceded cue velocity during double-support duration suggesting anticipatory control. Peak toe velocity nearly coincided with its most-correlated cue velocity during single-support duration. The toe-off concluding step and double-support durations followed their most-correlated cue velocity, suggesting feedback control. Cue-tracking accuracy and cue velocity correlations with timing parameters were higher with the manual contact cue than visual cue. The cue/gait timing relationships generalized across cue modalities, albeit with greater delays of step-cycle events relative to manual contact cue velocity. We conclude that individual kinematic parameters of gait are controlled to achieve a desired velocity at different specific times during the gait cycle. The overall timing pattern of instantaneous cue velocities associated with different gait parameters is conserved across cues that afford different performance accuracies. This timing pattern may be temporally shifted to optimize control. Different cue/gait parameter latencies in our nonadaptation paradigm provide general-case evidence of the independent control of gait parameters previously demonstrated in gait adaptation paradigms. PMID:26936979

Comparison of spatiotemporal and energy cost of the use of 3 different walkers and unassisted walking in older adults.

PubMed

Protas, Elizabeth J; Raines, Mary Lynn; Tissier, Sandrine

2007-06-01

To compare temporal, spatial, and oxygen costs of gait while elderly subjects walked without an assistive device, with a new assistive device, and with 2 other commercially available assistive devices. Descriptive, repeated measures. University-based research laboratory. Thirteen healthy older subjects who could walk without an assistive device. Not applicable. Gait speed, normalized gait speed, cadence, stride lengths, 5-minute walk distance and gait speed, oxygen consumption (Vo2) per meter walked, respiratory exchange ratio (RER) per meter walked, and minute ventilation per meter walked. Gait speed, normalized gait speed, and stride lengths decreased when the Merry Walker device was used, compared with walking without an assistive device. Outcome measures when walking with either the wheeled walker or the WalkAbout did not differ significantly from walking without a device except for a faster cadence with the WalkAbout. The distance walked and gait speed were decreased and the RER and minute ventilation were increased during the 5-minute walk with the Merry Walker compared with normal walking. The Vo2 was higher with the wheeled walker and Merry Walker than when walking without an assistive device, but there was no difference when the WalkAbout was used. Older adults walked in the new assistive device, the WalkAbout, with parameters that did not differ significantly from their gait without a device. The oxygen demands of walking were similar to unassisted walking for the WalkAbout, but were higher for the wheeled walker and Merry Walker. These results may help guide the prescription of assistive devices for older adults.

Spatiotemporal Parameters are not Substantially Influenced by Load Carriage or Inclination During Treadmill and Overground Walking

PubMed Central

Seay, Joseph F.; Gregorczyk, Karen N.; Hasselquist, Leif

2016-01-01

Abstract Influences of load carriage and inclination on spatiotemporal parameters were examined during treadmill and overground walking. Ten soldiers walked on a treadmill and overground with three load conditions (00 kg, 20 kg, 40 kg) during level, uphill (6% grade) and downhill (-6% grade) inclinations at self-selected speed, which was constant across conditions. Mean values and standard deviations for double support percentage, stride length and a step rate were compared across conditions. Double support percentage increased with load and inclination change from uphill to level walking, with a 0.4% stance greater increase at the 20 kg condition compared to 00 kg. As inclination changed from uphill to downhill, the step rate increased more overground (4.3 ± 3.5 steps/min) than during treadmill walking (1.7 ± 2.3 steps/min). For the 40 kg condition, the standard deviations were larger than the 00 kg condition for both the step rate and double support percentage. There was no change between modes for step rate standard deviation. For overground compared to treadmill walking, standard deviation for stride length and double support percentage increased and decreased, respectively. Changes in the load of up to 40 kg, inclination of 6% grade away from the level (i.e., uphill or downhill) and mode (treadmill and overground) produced small, yet statistically significant changes in spatiotemporal parameters. Variability, as assessed by standard deviation, was not systematically lower during treadmill walking compared to overground walking. Due to the small magnitude of changes, treadmill walking appears to replicate the spatiotemporal parameters of overground walking. PMID:28149338

An innovative training program based on virtual reality and treadmill: effects on gait of persons with multiple sclerosis.

PubMed

Peruzzi, Agnese; Zarbo, Ignazio Roberto; Cereatti, Andrea; Della Croce, Ugo; Mirelman, Anat

2017-07-01

In this single blind randomized controlled trial, we examined the effect of a virtual reality-based training on gait of people with multiple sclerosis. Twenty-five individuals with multiple sclerosis with mild to moderate disability were randomly assigned to either the control group (n = 11) or the experimental group (n = 14). The subjects in the control group received treadmill training. Subjects in the experimental group received virtual reality based treadmill training. Clinical measures and gait parameters were evaluated. Subjects in both the groups significantly improved the walking endurance and speed, cadence and stride length, lower limb joint ranges of motion and powers, during single and dual task gait. Moreover, subjects in the experimental group also improved balance, as indicated by the results of the clinical motor tests (p < 0.05). Between-group comparisons revealed that the experimental group improved significantly more than control group in hip range of motion and hip generated power at terminal stance at post-training. Our results support the perceived benefits of training programs that incorporate virtual reality to improve gait measures in individuals with multiple sclerosis. Implication of rehabilitation Gait deficits are common in multiple sclerosis (85%) and worsen during dual task activities. Intensive and progressive treadmill training, with and without virtual reality, is effective on dual task gait in persons with multiple sclerosis. Virtual reality-based treadmill training requiring obstacle negotiation increases the range of motion and the power generated at the hip, consequently allowing longer stride length and, consequently, higher gait speed.

Feasibility of external rhythmic cueing with the Google Glass for improving gait in people with Parkinson's disease.

PubMed

Zhao, Yan; Nonnekes, Jorik; Storcken, Erik J M; Janssen, Sabine; van Wegen, Erwin E H; Bloem, Bastiaan R; Dorresteijn, Lucille D A; van Vugt, Jeroen P P; Heida, Tjitske; van Wezel, Richard J A

2016-06-01

New mobile technologies like smartglasses can deliver external cues that may improve gait in people with Parkinson's disease in their natural environment. However, the potential of these devices must first be assessed in controlled experiments. Therefore, we evaluated rhythmic visual and auditory cueing in a laboratory setting with a custom-made application for the Google Glass. Twelve participants (mean age = 66.8; mean disease duration = 13.6 years) were tested at end of dose. We compared several key gait parameters (walking speed, cadence, stride length, and stride length variability) and freezing of gait for three types of external cues (metronome, flashing light, and optic flow) and a control condition (no-cue). For all cueing conditions, the subjects completed several walking tasks of varying complexity. Seven inertial sensors attached to the feet, legs and pelvis captured motion data for gait analysis. Two experienced raters scored the presence and severity of freezing of gait using video recordings. User experience was evaluated through a semi-open interview. During cueing, a more stable gait pattern emerged, particularly on complicated walking courses; however, freezing of gait did not significantly decrease. The metronome was more effective than rhythmic visual cues and most preferred by the participants. Participants were overall positive about the usability of the Google Glass and willing to use it at home. Thus, smartglasses like the Google Glass could be used to provide personalized mobile cueing to support gait; however, in its current form, auditory cues seemed more effective than rhythmic visual cues.

Peripheral neuropathy is associated with more frequent falls in Parkinson's disease.

PubMed

Beaulieu, Mélanie L; Müller, Martijn L T M; Bohnen, Nicolaas I

2018-04-03

Peripheral neuropathy is a common condition in the elderly that can affect balance and gait. Postural imbalance and gait difficulties in Parkinson's disease (PD), therefore, may stem not only from the primary neurodegenerative process but also from age-related medical comorbidities. Elucidation of the effects of peripheral neuropathy on these difficulties in PD is important to provide more targeted and effective therapy. The purpose of this study was to investigate the association between lower-limb peripheral neuropathy and falls and gait performance in PD while accounting for disease-specific factors. From a total of 140 individuals with PD, 14 male participants met the criteria for peripheral neuropathy and were matched 1:1 for Hoehn & Yahr stage and duration of disease with 14 male participants without peripheral neuropathy. All participants underwent fall (retrospectively) and gait assessment, a clinical evaluation, and [ 11 C]dihydrotetrabenazine and [ 11 C]methylpiperidin-4-yl propionate PET imaging to assess dopaminergic and cholinergic denervation, respectively. The presence of peripheral neuropathy was significantly associated with more falls (50% vs. 14%, p = 0.043), as well as a shorter stride length (p = 0.011) and greater stride length variability (p = 0.004), which resulted in slower gait speed (p = 0.016) during level walking. There was no significant difference in nigrostriatal dopaminergic denervation, cortical and thalamic cholinergic denervation, and MDS-UPDRS motor examination scores between groups. Lower-limb peripheral neuropathy is significantly associated with more falls and gait difficulties in PD. Thus, treating such neuropathy may reduce falls and/or improve gait performance in PD. Copyright © 2018 Elsevier Ltd. All rights reserved.

Underwater gait analysis in Parkinson's disease.

PubMed

Volpe, Daniele; Pavan, Davide; Morris, Meg; Guiotto, Annamaria; Iansek, Robert; Fortuna, Sofia; Frazzitta, Giuseppe; Sawacha, Zimi

2017-02-01

Although hydrotherapy is one of the physical therapies adopted to optimize gait rehabilitation in people with Parkinson disease, the quantitative measurement of gait-related outcomes has not been provided yet. This work aims to document the gait improvements in a group of parkinsonians after a hydrotherapy program through 2D and 3D underwater and on land gait analysis. Thirty-four parkinsonians and twenty-two controls were enrolled, divided into two different cohorts. In the first one, 2 groups of patients underwent underwater or land based walking training; controls underwent underwater walking training. Hence pre-treatment 2D underwater and on land gait analysis were performed, together with post-treatment on land gait analysis. Considering that current literature documented a reduced movement amplitude in parkinsonians across all lower limb joints in all movement planes, 3D underwater and on land gait analysis were performed on a second cohort of subjects (10 parkinsonians and 10 controls) who underwent underwater gait training. Baseline land 2D and 3D gait analysis in parkinsonians showed shorter stride length and slower speed than controls, in agreement with previous findings. Comparison between underwater and on land gait analysis showed reduction in stride length, cadence and speed on both parkinsonians and controls. Although patients who underwent underwater treatment exhibited significant changes on spatiotemporal parameters and sagittal plane lower limb kinematics, 3D gait analysis documented a significant (p<0.05) improvement in all movement planes. These data deserve attention for research directions promoting the optimal recovery and maintenance of walking ability. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

Effects of fatigue on kinematics and kinetics during overground running: a systematic review.

PubMed

Winter, Sara; Gordon, Susan; Watt, Kerrianne

2017-06-01

Understanding kinematic and kinetic changes with fatigue during running is important to assess changes that may influence performance and injury. The aim of this systematic review was to identify, critique and summarize literature about the effects of fatigue on kinematics and kinetics during a fatiguing overground run and present the reported influence on performance and injury. An electronic search was conducted of MEDLINE, SPORTDiscus, CINAHL and PubMed databases. Two reviewers assessed articles for inclusion, and evaluated the quality of articles included using a modified version of the Downs and Black Quality Index. A total of twelve articles were identified for review. The mean quality assessment score was seven out of a possible 12. Kinematic and kinetic changes reported to affect performance included decreased speed, step or stride frequency and length, increased trunk flexion, lower leg position at heel strike, mediolateral acceleration, changes in hip and knee ranges, and decreased stride regularity, heel lift, maximum knee rotation and backward ankle velocity. Alterations reported to increase risk of injury included decreased step frequency, increased upper body rotation and lower leg position at heel strike, and decreased knee flexion during stance. Reduced risk of injury has been linked to decreased step length and hip ranges, and increased trunk flexion. This review found limited evidence regarding changes in kinematic and kinetic during a fatiguing run in relation to performance and injury. Higher quality studies are warranted, with a larger sample of homogenous runners, and type of run carefully selected to provide quality information for runners, coaches and clinicians.

Spatiotemporal, kinematic, and kinetic effects of a peroneal nerve stimulator versus an ankle foot orthosis in hemiparetic gait.

PubMed

Sheffler, Lynne R; Bailey, Stephanie Nogan; Wilson, Richard D; Chae, John

2013-06-01

The relative effect of a transcutaneous peroneal nerve stimulator (tPNS) and an ankle foot orthosis (AFO) on spatiotemporal, kinematic, and kinetic parameters of hemiparetic gait has not been well described. To compare the relative neuroprosthetic effect of a tPNS with the orthotic effect of an AFO using quantitative gait analysis (QGA). In all, 12 stroke survivors underwent QGA under 3 device conditions: (1) no device (ND), (2) AFO, and (3) tPNS. A series of repeated-measures analyses of variance (rmANOVAs) were performed with dorsiflexion status (presence or absence of volitional dorsiflexion) as a covariate to compare selected spatiotemporal, kinematic, and kinetic parameters for each device condition. Post hoc pairwise comparisons and/or subset analysis by dorsiflexion status were performed for significant effect. Stride length was improved with both the AFO (P = .035) and the tPNS (P = .029) relative to ND. Those with absent dorsiflexion had longer stride length with the tPNS relative to ND (P = .034) and a higher walking velocity with a tPNS relative to the AFO (P = .015). There was no device effect on dorsiflexion angle at initial contact; however, a significant Device × Dorsiflexion status interaction effect favored the AFO relative to ND (P = .025) in those with dorsiflexion present. This study suggests that level of motor impairment may influence the relative effects of the tPNS and AFO devices in chronic hemiparetic gait; however, the small sample size limits generalizability. Future studies are necessary to determine if motor impairment level should be considered in the clinical prescription of these devices.

Gait training with partial body weight support during overground walking for individuals with chronic stroke: a pilot study

PubMed Central

2011-01-01

Background It is not yet established if the use of body weight support (BWS) systems for gait training is effective per se or if it is the combination of BWS and treadmill that improves the locomotion of individuals with gait impairment. This study investigated the effects of gait training on ground level with partial BWS in individuals with stroke during overground walking with no BWS. Methods Twelve individuals with chronic stroke (53.17 ± 7.52 years old) participated of a gait training program with BWS during overground walking, and were evaluated before and after the gait training period. In both evaluations, individuals were videotaped walking at a self-selected comfortable speed with no BWS. Measurements were obtained for mean walking speed, step length, stride length and speed, toe-clearance, durations of total double stance and single-limb support, and minimum and maximum foot, shank, thigh, and trunk segmental angles. Results After gait training, individuals walked faster, with symmetrical steps, longer and faster strides, and increased toe-clearance. Also, they displayed increased rotation of foot, shank, thigh, and trunk segmental angles on both sides of the body. However, the duration of single-limb support remained asymmetrical between each side of the body after gait training. Conclusions Gait training individuals with chronic stroke with BWS during overground walking improved walking in terms of temporal-spatial parameters and segmental angles. This training strategy might be adopted as a safe, specific and promising strategy for gait rehabilitation after stroke. PMID:21864373

Trunk motion and gait characteristics of pregnant women when walking: report of a longitudinal study with a control group

PubMed Central

2013-01-01

Background A longitudinal repeated measures design over pregnancy and post-birth, with a control group would provide insight into the mechanical adaptations of the body under conditions of changing load during a common female human lifespan condition, while minimizing the influences of inter human differences. The objective was to investigate systematic changes in the range of motion for the pelvic and thoracic segments of the spine, the motion between these segments (thoracolumbar spine) and temporospatial characteristics of step width, stride length and velocity during walking as pregnancy progresses and post-birth. Methods Nine pregnant women were investigated when walking along a walkway at a self-selected velocity using an 8 camera motion analysis system on four occasions throughout pregnancy and once post birth. A control group of twelve non-pregnant nulliparous women were tested on three occasions over the same time period. The existence of linear trends for change was investigated. Results As pregnancy progresses there was a significant linear trend for increase in step width (p = 0.05) and a significant linear trend for decrease in stride length (p = 0.05). Concurrently there was a significant linear trend for decrease in the range of motion of the pelvic segment (p = 0.03) and thoracolumbar spine (p = 0.01) about a vertical axis (side to side rotation), and the pelvic segment (p = 0.04) range of motion around an anterio-posterior axis (side tilt). Post-birth, step width readapted whereas pelvic (p = 0.02) and thoracic (p < 0.001) segment flexion-extension range of motion decreased and increased respectively. The magnitude of all changes was greater than that accounted for with natural variability with re testing. Conclusions As pregnancy progressed and post-birth there were significant linear trends seen in biomechanical changes when walking at a self-determined natural speed that were greater than that accounted for by natural variability with repeated testing. Not all adaptations were resolved by eight weeks post birth. PMID:23514204

Functional implications of muscle co-contraction during gait in advanced age.

PubMed

Lo, Justine; Lo, On-Yee; Olson, Erin A; Habtemariam, Daniel; Iloputaife, Ikechukwu; Gagnon, Margaret M; Manor, Brad; Lipsitz, Lewis A

2017-03-01

Older adults often exhibit high levels of lower extremity muscle co-contraction, which may be the cause or effect of age-related impairments in gait and associated falls. Normal gait requires intact executive function and thus can be slowed by challenging executive resources available to the neuromuscular system through the performance of a dual task. We therefore investigated associations between lower limb co-contraction and gait characteristics under normal and dual task conditions in healthy older adults (85.4±5.9years). We hypothesized that greater co-contraction is associated with slower gait speed during dual task conditions that stress executive and attentional abilities. Co-contraction was quantified during different phases of the gait cycle using surface electromyography (EMG) signals obtained from the anterior tibialis and lateral gastrocnemius while walking at preferred speed during normal and dual task conditions. Variables included the time difference to complete the Trail Making Test A and B (ΔTMT) and gait measures during normal or dual task walking. Higher co-contraction levels during the swing phase of both normal and dual task walking were associated with longer ΔTMT (normal: R 2 =0.25, p=0.02; dual task: R 2 =0.27, p=0.01). Co-contraction was associated with gait measures during dual task walking only; greater co-contraction levels during stride and stance were associated with slower gait speed (stride: R 2 =0.38, p=0.04; stance: R 2 =0.38, p=0.04), and greater co-contraction during stride was associated with longer stride time (R 2 =0.16, p=0.03). Our results suggest that relatively high lower limb co-contraction may explain some of the mobility impairments associated with the conduct of executive tasks in older adults. Copyright © 2017 Elsevier B.V. All rights reserved.

METABOLIC SYNDROME AND DAILY AMBULATION IN CHILDREN, ADOLESCENTS, AND YOUNG ADULTS

PubMed Central

Gardner, Andrew W.; Parker, Donald E.; Krishnan, Sowmya; Chalmers, Laura J.

2012-01-01

Purposes To compare daily ambulatory measures in children, adolescents, and young adults with and without metabolic syndrome, and to assess which metabolic syndrome components, demographic measures, and body composition measures are associated with daily ambulatory measures. Methods Two-hundred fifty subjects between the ages of 10 and 30 years were assessed on metabolic syndrome components, demographic and clinical measures, body fat percentage, and daily ambulatory strides, durations, and cadences during seven consecutive days. Forty-five of the 250 subjects had metabolic syndrome, as defined by the International Diabetes Federation. Results Subjects with metabolic syndrome ambulated at a slower daily average cadence than those without metabolic syndrome (13.6 ± 2.2 strides/min vs. 14.9 ± 3.2 strides/min; p=0.012), and they had slower cadences for continuous durations of 60 minutes (p=0.006), 30 minutes (p=0.005), 20 minutes (p=0.003), 5 minutes (p=0.002), and 1 minute (p=0.001). However, the total amount of time spent ambulating each day was not different (p=0.077). After adjustment for metabolic syndrome status, average cadence is linearly associated with body fat percentage (p<0.001) and fat mass (p<0.01). Group difference in average cadence was no longer significant after adjusting for body fat percentage (p=0.683) and fat mass (p=0.973). Conclusion Children, adolescents, and young adults with metabolic syndrome ambulate more slowly and take fewer strides throughout the day than those without metabolic syndrome, even though the total amount of time spent ambulating is not different. Furthermore, the detrimental influence of metabolic syndrome on ambulatory cadence is primarily a function of body fatness. PMID:22811038

The influence of gait speed on the stability of walking among the elderly.

PubMed

Fan, Yifang; Li, Zhiyu; Han, Shuyan; Lv, Changsheng; Zhang, Bo

2016-06-01

Walking speed is a basic factor to consider when walking exercises are prescribed as part of a training programme. Although associations between walking speed, step length and falling risk have been identified, the relationship between spontaneous walking pattern and falling risk remains unclear. The present study, therefore, examined the stability of spontaneous walking at normal, fast and slow speed among elderly (67.5±3.23) and young (21.4±1.31) individuals. In all, 55 participants undertook a test that involved walking on a plantar pressure platform. Foot-ground contact data were used to calculate walking speed, step length, pressure impulse along the plantar-impulse principal axis and pressure record of time series along the plantar-impulse principal axis. A forward dynamics method was used to calculate acceleration, velocity and displacement of the centre of mass in the vertical direction. The results showed that when the elderly walked at different speeds, their average step length was smaller than that observed among the young (p=0.000), whereas their anterior/posterior variability and lateral variability had no significant difference. When walking was performed at normal or slow speed, no significant between-group difference in cadence was found. When walking at a fast speed, the elderly increased their stride length moderately and their cadence greatly (p=0.012). In summary, the present study found no correlation between fast walking speed and instability among the elderly, which indicates that healthy elderly individuals might safely perform fast-speed walking exercises. Copyright © 2016 Elsevier B.V. All rights reserved.

A pediatric correlational study of stride interval dynamics, energy expenditure and activity level.

PubMed

Ellis, Denine; Sejdic, Ervin; Zabjek, Karl; Chau, Tom

2014-08-01

The strength of time-dependent correlations known as stride interval (SI) dynamics has been proposed as an indicator of neurologically healthy gait. Most recently, it has been hypothesized that these dynamics may be necessary for gait efficiency although the supporting evidence to date is scant. The current study examines over-ground SI dynamics, and their relationship with the cost of walking and physical activity levels in neurologically healthy children aged nine to 15 years. Twenty participants completed a single experimental session consisting of three phases: 10 min resting, 15 min walking and 10 min recovery. The scaling exponent (α) was used to characterize SI dynamics while net energy cost was measured using a portable metabolic cart, and physical activity levels were determined based on a 7-day recall questionnaire. No significant linear relationships were found between a and the net energy cost measures (r < .07; p > .25) or between α and physical activity levels (r = .01, p = .62). However, there was a marked reduction in the variance of α as activity levels increased. Over-ground stride dynamics do not appear to directly reflect energy conservation of gait in neurologically healthy youth. However, the reduction in the variance of α with increasing physical activity suggests a potential exercise-moderated convergence toward a level of stride interval persistence for able-bodied youth reported in the literature. This latter finding warrants further investigation.

Gait in adolescent idiopathic scoliosis: kinematics and electromyographic analysis.

PubMed

Mahaudens, P; Banse, X; Mousny, M; Detrembleur, C

2009-04-01

Adolescent idiopathic scoliosis (AIS) is a progressive growth disease that affects spinal anatomy, mobility, and left-right trunk symmetry. Consequently, AIS can modify human locomotion. Very few studies have investigated a simple activity like walking in a cohort of well-defined untreated patients with scoliosis. The first goal of this study is to evaluate the effects of scoliosis and scoliosis severity on kinematic and electromyographic (EMG) gait variables compared to an able-bodied population. The second goal is to look for any asymmetry in these parameters during walking. Thirteen healthy girls and 41 females with untreated AIS, with left thoracolumbar or lumbar primary structural curves were assessed. AIS patients were divided into three clinical subgroups (group 1 < 20 degrees, group 2 between 20 and 40 degrees, and group 3 > 40 degrees). Gait analysis included synchronous bilateral kinematic and EMG measurements. The subjects walked on a treadmill at 4 km/h (comfortable speed). The tridimensional (3D) shoulder, pelvis, and lower limb motions were measured using 22 reflective markers tracked by four infrared cameras. The EMG timing activity was measured using bipolar surface electrodes on quadratus lumborum, erector spinae, gluteus medius, rectus femoris, semitendinosus, tibialis anterior, and gastrocnemius muscles. Statistical comparisons (ANOVA) were performed across groups and sides for kinematic and EMG parameters. The step length was reduced in AIS compared to normal subjects (7% less). Frontal shoulder, pelvis, and hip motion and transversal hip motion were reduced in scoliosis patients (respectively, 21, 27, 28, and 22% less). The EMG recording during walking showed that the quadratus lumborum, erector spinae, gluteus medius, and semitendinosus muscles contracted during a longer part of the stride in scoliotic patients (46% of the stride) compared with normal subjects (35% of the stride). There was no significant difference between scoliosis groups 1, 2, and 3 for any of the kinematic and EMG parameters, meaning that severe scoliosis was not associated with increased differences in gait parameters compared to mild scoliosis. Scoliosis was not associated with any kinematic or EMG left-right asymmetry. In conclusion, scoliosis patients showed significant but slight modifications in gait, even in cases of mild scoliosis. With the naked eye, one could not see any difference from controls, but with powerful gait analysis technology, the pelvic frontal motion (right-left tilting) was reduced, as was the motion in the hips and shoulder. Surprisingly, no asymmetry was noted but the spine seemed dynamically stiffened by the longer contraction time of major spinal and pelvic muscles. Further studies are needed to evaluate the origin and consequences of these observations.

Changes in Knee Biomechanics After a Hip-Abductor Strengthening Protocol for Runners With Patellofemoral Pain Syndrome

PubMed Central

Ferber, Reed; Kendall, Karen D.; Farr, Lindsay

2011-01-01

Abstract Context: Very few authors have investigated the relationship between hip-abductor muscle strength and frontal-plane knee mechanics during running. Objective: To investigate this relationship using a 3-week hip-abductor muscle-strengthening program to identify changes in strength, pain, and biomechanics in runners with patellofemoral pain syndrome (PFPS). Design: Cohort study. Setting: University-based clinical research laboratory. Patients or Other Participants: Fifteen individuals (5 men, 10 women) with PFPS and 10 individuals without PFPS (4 men, 6 women) participated. Intervention(s): The patients with PFPS completed a 3-week hip-abductor strengthening protocol; control participants did not. Main Outcome Measure(s): The dependent variables of interest were maximal isometric hip-abductor muscle strength, 2-dimensional peak knee genu valgum angle, and stride-to-stride knee-joint variability. All measures were recorded at baseline and 3 weeks later. Between-groups differences were compared using repeated-measures analyses of variance. Results: At baseline, the PFPS group exhibited reduced strength, no difference in peak genu valgum angle, and increased stride-to-stride knee-joint variability compared with the control group. After the 3-week protocol, the PFPS group demonstrated increased strength, less pain, no change in peak genu valgum angle, and reduced stride-to-stride knee-joint variability compared with baseline. Conclusions: A 3-week hip-abductor muscle-strengthening protocol was effective in increasing muscle strength and decreasing pain and stride-to-stride knee-joint variability in individuals with PFPS. However, concomitant changes in peak knee genu valgum angle were not observed. PMID:21391799

The influence of officer equipment and protection on short sprinting performance.

PubMed

Lewinski, William J; Dysterheft, Jennifer L; Dicks, Nathan D; Pettitt, Robert W

2015-03-01

As advances in protective equipment are made, it has been observed that the weight law enforcement officers must carry every day is greatly increasing. Many investigations have noted the health risks of these increases, yet none have looked at its effects on officer mobility. The primary purpose of this study was to examine the influence of both the weight of officer safety equipment, as well as a lateral focal point (FP), on the stride length, stride velocity, and acceleration of the first six strides of a short sprint. Twenty male law enforcement students performed two maximal effort sprint trials, in the participating college's gymnasium, from each of four starting positions: forwards (control position), backwards, 90° left, and 90° right. Subjects placed in the FP group (n = 9) were required to maintain focus on lateral FP during the 90° left and 90° right trials, and a forwards FP during the backwards trials. On a second testing date, subjects repeated the sprint tests while wearing a 9.07 kg weight belt, simulating officer equipment and protective gear. The belt averaged 11.47 ± 1.64% of subject body mass. A significant main effect of weight belt trials was found (F = 20.494, p < 0.01), in which significant decreases were found for velocity and acceleration. No other significant effects were found as a result of starting position or focal point and no significant interactions were found between independent variables. Conclusively, the results of this study show the increasing weights of duty gear and protective equipment have detrimental effects on officer velocity and acceleration, impeding their mobility, which may be dangerous in use of force or threatening situations. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Evaluation of factors that affect hip moment impulse during gait: A systematic review.

PubMed

Inai, Takuma; Takabayashi, Tomoya; Edama, Mutsuaki; Kubo, Masayoshi

2018-03-01

Decreasing the daily cumulative hip moments in the frontal and sagittal planes may lower the risk of hip osteoarthritis. Therefore, it may be important to evaluate factors that affect hip moment impulse during gait. It is unclear what factors affect hip moment impulse during gait. This systematic review aimed to evaluate different factors that affect hip moment impulse during gait in healthy adults and patients with hip osteoarthritis. Four databases (Scopus, ScienceDirect, PubMed, and PEDro) were searched up to August 2017 to identify studies that examined hip moment impulse during gait. Data extracted for analysis included the sample size, age, height, body mass, type of intervention, and main findings. After screening, 10 of the 975 studies identified were included in our analysis. Several factors, including a rocker bottom shoe, FitFlop™ sandals, ankle push-off, posture, stride length, body-weight unloading, a rollator, walking poles, and a knee brace, were reviewed. The main findings were as follows: increasing ankle push-off decreased both the hip flexion and extension moment impulses; body-weight unloading decreased both the hip extension and adduction moment impulses; the FitFlop™ sandal increased the sum of the hip flexion and extension moment impulses; long strides increased the hip extension moment impulse; and the use of a knee brace increased hip flexion moment impulse. Of note, none of the eligible studies included patients with hip osteoarthritis. The hip moment impulses can be modified by person-specific factors (ankle push-off and long strides) and external factors (body-weight unloading and use of the FitFlop™ sandals and a knee brace). Effects on the progression of hip osteoarthritis remain to be evaluated. Copyright © 2018 Elsevier B.V. All rights reserved.

The Stride Rite Intergenerational Day Care Center: Background.

ERIC Educational Resources Information Center

Stride Rite Corp., Cambridge, MA.

The Stride Rite Intergenerational Day Care Center is located in the Stride Rite Corporation's headquarters in Cambridge, Massachusetts. The facility is designed to provide day care to both children and elders, using two separate wings to afford privacy to each group and a large central area for informal interaction between children and elders. The…

STRIDE: Species Tree Root Inference from Gene Duplication Events.

PubMed

Emms, David M; Kelly, Steven

2017-12-01

The correct interpretation of any phylogenetic tree is dependent on that tree being correctly rooted. We present STRIDE, a fast, effective, and outgroup-free method for identification of gene duplication events and species tree root inference in large-scale molecular phylogenetic analyses. STRIDE identifies sets of well-supported in-group gene duplication events from a set of unrooted gene trees, and analyses these events to infer a probability distribution over an unrooted species tree for the location of its root. We show that STRIDE correctly identifies the root of the species tree in multiple large-scale molecular phylogenetic data sets spanning a wide range of timescales and taxonomic groups. We demonstrate that the novel probability model implemented in STRIDE can accurately represent the ambiguity in species tree root assignment for data sets where information is limited. Furthermore, application of STRIDE to outgroup-free inference of the origin of the eukaryotic tree resulted in a root probability distribution that provides additional support for leading hypotheses for the origin of the eukaryotes. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Project Stride: An Equine-Assisted Intervention to Reduce Symptoms of Social Anxiety in Young Women.

PubMed

Alfonso, Sarah V; Alfonso, Lauren A; Llabre, Maria M; Fernandez, M Isabel

2015-01-01

Although there is evidence supporting the use of equine-assisted activities to treat mental disorders, its efficacy in reducing signs and symptoms of social anxiety in young women has not been examined. We developed and pilot tested Project Stride, a brief, six-session intervention combining equine-assisted activities and cognitive-behavioral strategies to reduce symptoms of social anxiety. A total of 12 women, 18-29 years of age, were randomly assigned to Project Stride or a no-treatment control. Participants completed the Liebowitz Social Anxiety Scale at baseline, immediate-post, and 6 weeks after treatment. Project Stride was highly acceptable and feasible. Compared to control participants, those in Project Stride had significantly greater reductions in social anxiety scores from baseline to immediate-post [decrease of 24.8 points; t (9) = 3.40, P = .008)] and from baseline to follow-up [decrease of 31.8 points; t (9) = 4.12, P = .003)]. These findings support conducting a full-scale efficacy trial of Project Stride. Copyright © 2015 Elsevier Inc. All rights reserved.

Water depth effects on impact loading, kinematic and physiological variables during water treadmill running.

PubMed

Macdermid, Paul W; Wharton, Josh; Schill, Carina; Fink, Philip W

2017-07-01

The purpose of this study was to compare impact loading, kinematic and physiological responses to three different immersion depths (mid-shin, mid-thigh, and xiphoid process) while running at the same speed on a water based treadmill. Participants (N=8) ran on a water treadmill at three depths for 3min. Tri-axial accelerometers were used to identify running dynamics plus measures associated with impact loading rates, while heart rate data were logged to indicate physiological demand. Participants had greater peak impact accelerations (p<0.01), greater impact loading rates (p<0.0001), greater stride frequency (p<0.05), shorter stride length (p<0.01), and greater rate of acceleration development at toe-off (p<0.0001) for the mid-shin and mid-thigh compared to running immersed to the xiphoid process. Physiological effort determined by heart rate was also significantly less (p<0.0001) when running immersed to the xiphoid process. Water immersed treadmill running above the waistline alters kinematics of gait, reduces variables associated with impact, while decreasing physiological demand compared to depths below the waistline. Copyright © 2017 Elsevier B.V. All rights reserved.

Length and elasticity of side reins affect rein tension at trot.

PubMed

Clayton, Hilary M; Larson, Britt; Kaiser, LeeAnn J; Lavagnino, Michael

2011-06-01

This study investigated the horse's contribution to tension in the reins. The experimental hypotheses were that tension in side reins (1) increases biphasically in each trot stride, (2) changes inversely with rein length, and (3) changes with elasticity of the reins. Eight riding horses trotted in hand at consistent speed in a straight line wearing a bit and bridle and three types of side reins (inelastic, stiff elastic, compliant elastic) were evaluated in random order at long, neutral, and short lengths. Strain gauge transducers (240 Hz) measured minimal, maximal and mean rein tension, rate of loading and impulse. The effects of rein type and length were evaluated using ANOVA with Bonferroni post hoc tests. Rein tension oscillated in a regular pattern with a peak during each diagonal stance phase. Within each rein type, minimal, maximal and mean tensions were higher with shorter reins. At neutral or short lengths, minimal tension increased and maximal tension decreased with elasticity of the reins. Short, inelastic reins had the highest maximal tension and rate of loading. Since the tension variables respond differently to rein elasticity at different lengths, it is recommended that a set of variables representing different aspects of rein tension should be reported. Copyright © 2010 Elsevier Ltd. All rights reserved.

Scale effects and morphological diversification in hindlimb segment mass proportions in neognath birds.

PubMed

Kilbourne, Brandon M

2014-01-01

In spite of considerable work on the linear proportions of limbs in amniotes, it remains unknown whether differences in scale effects between proximal and distal limb segments has the potential to influence locomotor costs in amniote lineages and how changes in the mass proportions of limbs have factored into amniote diversification. To broaden our understanding of how the mass proportions of limbs vary within amniote lineages, I collected data on hindlimb segment masses - thigh, shank, pes, tarsometatarsal segment, and digits - from 38 species of neognath birds, one of the most speciose amniote clades. I scaled each of these traits against measures of body size (body mass) and hindlimb size (hindlimb length) to test for departures from isometry. Additionally, I applied two parameters of trait evolution (Pagel's λ and δ) to understand patterns of diversification in hindlimb segment mass in neognaths. All segment masses are positively allometric with body mass. Segment masses are isometric with hindlimb length. When examining scale effects in the neognath subclade Land Birds, segment masses were again positively allometric with body mass; however, shank, pedal, and tarsometatarsal segment masses were also positively allometric with hindlimb length. Methods of branch length scaling to detect phylogenetic signal (i.e., Pagel's λ) and increasing or decreasing rates of trait change over time (i.e., Pagel's δ) suffer from wide confidence intervals, likely due to small sample size and deep divergence times. The scaling of segment masses appears to be more strongly related to the scaling of limb bone mass as opposed to length, and the scaling of hindlimb mass distribution is more a function of scale effects in limb posture than proximo-distal differences in the scaling of limb segment mass. Though negative allometry of segment masses appears to be precluded by the need for mechanically sound limbs, the positive allometry of segment masses relative to body mass may underlie scale effects in stride frequency and length between smaller and larger neognaths. While variation in linear proportions of limbs appear to be governed by developmental mechanisms, variation in mass proportions does not appear to be constrained so.

Scale effects and morphological diversification in hindlimb segment mass proportions in neognath birds

PubMed Central

2014-01-01

Introduction In spite of considerable work on the linear proportions of limbs in amniotes, it remains unknown whether differences in scale effects between proximal and distal limb segments has the potential to influence locomotor costs in amniote lineages and how changes in the mass proportions of limbs have factored into amniote diversification. To broaden our understanding of how the mass proportions of limbs vary within amniote lineages, I collected data on hindlimb segment masses – thigh, shank, pes, tarsometatarsal segment, and digits – from 38 species of neognath birds, one of the most speciose amniote clades. I scaled each of these traits against measures of body size (body mass) and hindlimb size (hindlimb length) to test for departures from isometry. Additionally, I applied two parameters of trait evolution (Pagel’s λ and δ) to understand patterns of diversification in hindlimb segment mass in neognaths. Results All segment masses are positively allometric with body mass. Segment masses are isometric with hindlimb length. When examining scale effects in the neognath subclade Land Birds, segment masses were again positively allometric with body mass; however, shank, pedal, and tarsometatarsal segment masses were also positively allometric with hindlimb length. Methods of branch length scaling to detect phylogenetic signal (i.e., Pagel’s λ) and increasing or decreasing rates of trait change over time (i.e., Pagel’s δ) suffer from wide confidence intervals, likely due to small sample size and deep divergence times. Conclusions The scaling of segment masses appears to be more strongly related to the scaling of limb bone mass as opposed to length, and the scaling of hindlimb mass distribution is more a function of scale effects in limb posture than proximo-distal differences in the scaling of limb segment mass. Though negative allometry of segment masses appears to be precluded by the need for mechanically sound limbs, the positive allometry of segment masses relative to body mass may underlie scale effects in stride frequency and length between smaller and larger neognaths. While variation in linear proportions of limbs appear to be governed by developmental mechanisms, variation in mass proportions does not appear to be constrained so. PMID:24876886

Quantifying performance and effects of load carriage during a challenging balancing task using an array of wireless inertial sensors.

PubMed

Cain, Stephen M; McGinnis, Ryan S; Davidson, Steven P; Vitali, Rachel V; Perkins, Noel C; McLean, Scott G

2016-01-01

We utilize an array of wireless inertial measurement units (IMUs) to measure the movements of subjects (n=30) traversing an outdoor balance beam (zigzag and sloping) as quickly as possible both with and without load (20.5kg). Our objectives are: (1) to use IMU array data to calculate metrics that quantify performance (speed and stability) and (2) to investigate the effects of load on performance. We hypothesize that added load significantly decreases subject speed yet results in increased stability of subject movements. We propose and evaluate five performance metrics: (1) time to cross beam (less time=more speed), (2) percentage of total time spent in double support (more double support time=more stable), (3) stride duration (longer stride duration=more stable), (4) ratio of sacrum M-L to A-P acceleration (lower ratio=less lateral balance corrections=more stable), and (5) M-L torso range of motion (smaller range of motion=less balance corrections=more stable). We find that the total time to cross the beam increases with load (t=4.85, p<0.001). Stability metrics also change significantly with load, all indicating increased stability. In particular, double support time increases (t=6.04, p<0.001), stride duration increases (t=3.436, p=0.002), the ratio of sacrum acceleration RMS decreases (t=-5.56, p<0.001), and the M-L torso lean range of motion decreases (t=-2.82, p=0.009). Overall, the IMU array successfully measures subject movement and gait parameters that reveal the trade-off between speed and stability in this highly dynamic balance task. Copyright © 2015 Elsevier B.V. All rights reserved.

Assessment of repeatability of a wireless, inertial sensor-based lameness evaluation system for horses.

PubMed

Keegan, Kevin G; Kramer, Joanne; Yonezawa, Yoshiharu; Maki, Hiromitchi; Pai, P Frank; Dent, Eric V; Kellerman, Thomas E; Wilson, David A; Reed, Shannon K

2011-09-01

To determine repeatability of a wireless, inertial sensor-based lameness evaluation system in horses. 236 horses. Horses were from 2 to 29 years of age and of various breeds and lameness disposition. All horses were instrumented with a wireless, inertial sensor-based motion analysis system on the head (accelerometer), pelvis (midline croup region [accelerometer]), and right forelimb (gyroscope) before evaluation in 2 consecutive trials, approximately 5 minutes apart, as the horse was trotted in a straight line. Signal-processing algorithms generated overall trial asymmetry measures for vertical head and pelvic movement and stride-by-stride differences in head and pelvic maximum and minimum positions between right and left sides of each stride. Repeatability was determined, and trial difference was determined for groups of horses with various numbers of strides for which data were collected per trial. Inertial sensor-based measures of torso movement asymmetry were repeatable. Repeatability for measures of torso asymmetry for determination of hind limb lameness was slightly greater than that for forelimb lameness. Collecting large numbers of strides degraded stride-to-stride repeatability but did not degrade intertrial repeatability. The inertial sensor system used to measure asymmetry of head and pelvic movement as an aid in the detection and evaluation of lameness in horses trotting in a straight line was sufficiently repeatable to investigate for clinical use.

Wearable sensors objectively measure gait parameters in Parkinson’s disease

PubMed Central

Marxreiter, Franz; Gossler, Julia; Kohl, Zacharias; Reinfelder, Samuel; Gassner, Heiko; Aminian, Kamiar; Eskofier, Bjoern M.; Winkler, Jürgen; Klucken, Jochen

2017-01-01

Distinct gait characteristics like short steps and shuffling gait are prototypical signs commonly observed in Parkinson’s disease. Routinely assessed by observation through clinicians, gait is rated as part of categorical clinical scores. There is an increasing need to provide quantitative measurements of gait, e.g. to provide detailed information about disease progression. Recently, we developed a wearable sensor-based gait analysis system as diagnostic tool that objectively assesses gait parameter in Parkinson’s disease without the need of having a specialized gait laboratory. This system consists of inertial sensor units attached laterally to both shoes. The computed target of measures are spatiotemporal gait parameters including stride length and time, stance phase time, heel-strike and toe-off angle, toe clearance, and inter-stride variation from gait sequences. To translate this prototype into medical care, we conducted a cross-sectional study including 190 Parkinson’s disease patients and 101 age-matched controls and measured gait characteristics during a 4x10 meter walk at the subjects’ preferred speed. To determine intraindividual changes in gait, we monitored the gait characteristics of 63 patients longitudinally. Cross-sectional analysis revealed distinct spatiotemporal gait parameter differences reflecting typical Parkinson’s disease gait characteristics including short steps, shuffling gait, and postural instability specific for different disease stages and levels of motor impairment. The longitudinal analysis revealed that gait parameters were sensitive to changes by mirroring the progressive nature of Parkinson’s disease and corresponded to physician ratings. Taken together, we successfully show that wearable sensor-based gait analysis reaches clinical applicability providing a high biomechanical resolution for gait impairment in Parkinson’s disease. These data demonstrate the feasibility and applicability of objective wearable sensor-based gait measurement in Parkinson’s disease reaching high technological readiness levels for both, large scale clinical studies and individual patient care. PMID:29020012

Gait Deviations in Children With Osteogenesis Imperfecta Type I.

PubMed

Garman, Christina R; Graf, Adam; Krzak, Joseph; Caudill, Angela; Smith, Peter; Harris, Gerald

2017-08-02

Osteogenesis imperfecta (OI) is a congenital connective tissue disorder often characterized by orthopaedic complications that impact normal gait. As such, mobility is of particular interest in the OI population as it is associated with multiple aspects of participation and quality of life. The purpose of the current study was to identify and describe common gait deviations in a large sample of individuals with type I OI and speculate the etiology with a goal of improving function. Gait analysis was performed on 44 subjects with type I (11.7±3.08 y old) and 30 typically developing controls (9.54±3.1 y old ). Spatial temporal, kinematic, and kinetic gait data were calculated from the Vicon Plug-in-Gait Model. Musculoskeletal modeling of the muscle tendon lengths (MTL) was done in OpenSim 3.3 to evaluate the MTL of the gastrocnemius and gluteus maximus. The gait deviation index, a dimensionless parameter that evaluates the deviation of 9 kinematic gait parameters from a control database, was also calculated. Walking speed, single support time, stride, and step length were lower and double support time was higher in the OI group. The gait deviation index score was lower and external hip rotation angle was higher in the OI group. Peak hip flexor, knee extensor and ankle plantarflexor moments, and power generation at the ankle were lower in the OI group. MTL analysis revealed no significant length discrepancies between the OI group and the typically developing group. Together, these findings provide a comprehensive description of gait characteristics among a group of individuals with type I OI. Such data inform clinicians about specific gait deviations in this population allowing clinicians to recommend more focused interventions. Level III-case-control study.

Periodic spring-mass running over uneven terrain through feedforward control of landing conditions.

PubMed

Palmer, Luther R; Eaton, Caitrin E

2014-09-01

This work pursues a feedforward control algorithm for high-speed legged locomotion over uneven terrain. Being able to rapidly negotiate uneven terrain without visual or a priori information about the terrain will allow legged systems to be used in time-critical applications and alongside fast-moving humans or vehicles. The algorithm is shown here implemented on a spring-loaded inverted pendulum model in simulation, and can be configured to approach fixed running height over uneven terrain or self-stable terrain following. Offline search identifies unique landing conditions that achieve a desired apex height with a constant stride period over varying ground levels. Because the time between the apex and touchdown events is directly related to ground height, the landing conditions can be computed in real time as continuous functions of this falling time. Enforcing a constant stride period reduces the need for inertial sensing of the apex event, which is nontrivial for physical systems, and allows for clocked feedfoward control of the swing leg.

Mechanics of the human hamstring muscles during sprinting.

PubMed

Schache, Anthony G; Dorn, Tim W; Blanch, Peter D; Brown, Nicholas A T; Pandy, Marcus G

2012-04-01

An understanding of hamstring mechanics during sprinting is important for elucidating why these muscles are so vulnerable to acute strain-type injury. The purpose of this study was twofold: first, to quantify the biomechanical load (specifically, musculotendon strain, velocity, force, power, and work) experienced by the hamstrings across a full stride cycle; and second, to determine how these parameters differ for each hamstring muscle (i.e., semimembranosus (SM), semitendinosus (ST), biceps femoris long head (BF), biceps femoris short head (BF)). Full-body kinematics and ground reaction force data were recorded simultaneously from seven subjects while sprinting on an indoor running track. Experimental data were integrated with a three-dimensional musculoskeletal computer model comprised of 12 body segments and 92 musculotendon structures. The model was used in conjunction with an optimization algorithm to calculate musculotendon strain, velocity, force, power, and work for the hamstrings. SM, ST, and BF all reached peak strain, produced peak force, and formed much negative work (energy absorption) during terminal swing. The biomechanical load differed for each hamstring muscle: BF exhibited the largest peak strain, ST displayed the greatest lengthening velocity, and SM produced the highest peak force, absorbed and generated the most power, and performed the largest amount of positive and negative work. As peak musculotendon force and strain for BF, ST, and SM occurred around the same time during terminal swing, it is suggested that this period in the stride cycle may be when the biarticular hamstrings are at greatest injury risk. On this basis, hamstring injury prevention or rehabilitation programs should preferentially target strengthening exercises that involve eccentric contractions performed with high loads at longer musculotendon lengths.

How innate is locomotion in precocial animals? A study on the early development of spatio-temporal gait variables and gait symmetry in piglets.

PubMed

Vanden Hole, Charlotte; Goyens, Jana; Prims, Sara; Fransen, Erik; Ayuso Hernando, Miriam; Van Cruchten, Steven; Aerts, Peter; Van Ginneken, Chris

2017-08-01

Locomotion is one of the most important ecological functions in animals. Precocial animals, such as pigs, are capable of independent locomotion shortly after birth. This raises the question whether coordinated movement patterns and the underlying muscular control in these animals is fully innate or whether there still exists a rapid maturation. We addressed this question by studying gait development in neonatal pigs through the analysis of spatio-temporal gait characteristics during locomotion at self-selected speed. To this end, we made video recordings of piglets walking along a corridor at several time points (from 0 h to 96 h). After digitization of the footfalls, we analysed self-selected speed and spatio-temporal characteristics (e.g. stride and step lengths, stride frequency and duty factor) to study dynamic similarity, intralimb coordination and interlimb coordination. To assess the variability of the gait pattern, left-right asymmetry was studied. To distinguish neuromotor maturation from effects caused by growth, both absolute and normalized data (according to the dynamic similarity concept) were included in the analysis. All normalized spatio-temporal variables reached stable values within 4 h of birth, with most of them showing little change after the age of 2 h. Most asymmetry indices showed stable values, hovering around 10%, within 8 h of birth. These results indicate that coordinated movement patterns are not entirely innate, but that a rapid neuromotor maturation, potentially also the result of the rearrangement or recombination of existing motor modules, takes place in these precocial animals. © 2017. Published by The Company of Biologists Ltd.

Age, experience and genetic background influence treadmill walking in mice

PubMed Central

Wooley, Christine M.; Xing, Shuqin; Burgess, Robert W.; Cox, Gregory A.; Seburn, Kevin L.

2009-01-01

WOOLEY, C.M., S. XING, R.W. BURGESS, G.A. COX, AND K.L. SEBURN. Age, experience and genetic background influence treadmill walking in mice. PHYSIOL. BEHAV. XX(X), XXX-XXX, 2008 – The use of a treadmill to gather data for gait analysis in mice is a convenient, sensitive method to evaluate motor performance. However, evidence from several species, including mice, shows that treadmill locomotion is a novel task that is not equivalent to over ground locomotion and that may be particularly sensitive to the test environment and protocol. We investigated the effects of age, genetic background and repeated trials on treadmill walking in mice and show that these factors are important considerations in the interpretation of gait data. Specifically we report that as C57BL/6J (B6) mice age, the animals use progressively longer, less frequent strides to maintain the same walking speed. The increase is most rapid between 1 and 6 months of age and is explained, in part, by changes in size and weight. We also extended previous findings showing that repeat trials cause mice to modify their treadmill gait pattern. In general, B6 mice tend to take shorter, more frequent steps and adopt a wider dynamic stance with repeated walking trials. The nature and extent of the response changes with both the number and timing of the trials and was observed with inter-trial intervals as long as 3 months. Finally, we compared the gait pattern of an additional seven inbred strains of mice and found significant variation in the length and frequency of strides used to maintain the same walking speed. The combined results offer the bases for further mechanistic studies and can be used to guide optimal experimental design. PMID:19027767

Randomized Controlled Trial of a Home-Based Action Observation Intervention to Improve Walking in Parkinson Disease.

PubMed

Jaywant, Abhishek; Ellis, Terry D; Roy, Serge; Lin, Cheng-Chieh; Neargarder, Sandy; Cronin-Golomb, Alice

2016-05-01

To examine the feasibility and efficacy of a home-based gait observation intervention for improving walking in Parkinson disease (PD). Participants were randomly assigned to an intervention or control condition. A baseline walking assessment, a training period at home, and a posttraining assessment were conducted. The laboratory and participants' home and community environments. Nondemented individuals with PD (N=23) experiencing walking difficulty. In the gait observation (intervention) condition, participants viewed videos of healthy and parkinsonian gait. In the landscape observation (control) condition, participants viewed videos of moving water. These tasks were completed daily for 8 days. Spatiotemporal walking variables were assessed using accelerometers in the laboratory (baseline and posttraining assessments) and continuously at home during the training period. Variables included daily activity, walking speed, stride length, stride frequency, leg swing time, and gait asymmetry. Questionnaires including the 39-item Parkinson Disease Questionnaire (PDQ-39) were administered to determine self-reported change in walking, as well as feasibility. At posttraining assessment, only the gait observation group reported significantly improved mobility (PDQ-39). No improvements were seen in accelerometer-derived walking data. Participants found the at-home training tasks and accelerometer feasible to use. Participants found procedures feasible and reported improved mobility, suggesting that observational training holds promise in the rehabilitation of walking in PD. Observational training alone, however, may not be sufficient to enhance walking in PD. A more challenging and adaptive task, and the use of explicit perceptual learning and practice of actions, may be required to effect change. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

The Risks and Benefits of Running Barefoot or in Minimalist Shoes

PubMed Central

Perkins, Kyle P.; Hanney, William J.; Rothschild, Carey E.

2014-01-01

Context: The popularity of running barefoot or in minimalist shoes has recently increased because of claims of injury prevention, enhanced running efficiency, and improved performance compared with running in shoes. Potential risks and benefits of running barefoot or in minimalist shoes have yet to be clearly defined. Objective: To determine the methodological quality and level of evidence pertaining to the risks and benefits of running barefoot or in minimalist shoes. Data Sources: In September 2013, a comprehensive search of the Ovid MEDLINE, SPORTDiscus, and CINAHL databases was performed by 2 independent reviewers. Study Selection: Included articles were obtained from peer-reviewed journals in the English language with no limit for year of publication. Final inclusion criteria required at least 1 of the following outcome variables: pain, injury rate, running economy, joint forces, running velocity, electromyography, muscle performance, or edema. Study Design: Systematic review. Level of Evidence: Level 3. Data Extraction: Two reviewers appraised each article using the Downs and Black checklist and appraised each for level of evidence. Results: Twenty-three articles met the criteria for this review. Of 27 possible points on the Downs and Black checklist, articles scored between 13 and 19 points, indicating a range of evidence from very limited to moderate. Moderate evidence supports the following biomechanical differences when running barefoot versus in shoes: overall less maximum vertical ground reaction forces, less extension moment and power absorption at the knee, less foot and ankle dorsiflexion at ground contact, less ground contact time, shorter stride length, increased stride frequency, and increased knee flexion at ground contact. Conclusion: Because of lack of high-quality evidence, no definitive conclusions can be drawn regarding specific risks or benefits to running barefoot, shod, or in minimalist shoes. PMID:25364479

The risks and benefits of running barefoot or in minimalist shoes: a systematic review.

PubMed

Perkins, Kyle P; Hanney, William J; Rothschild, Carey E

2014-11-01

The popularity of running barefoot or in minimalist shoes has recently increased because of claims of injury prevention, enhanced running efficiency, and improved performance compared with running in shoes. Potential risks and benefits of running barefoot or in minimalist shoes have yet to be clearly defined. To determine the methodological quality and level of evidence pertaining to the risks and benefits of running barefoot or in minimalist shoes. In September 2013, a comprehensive search of the Ovid MEDLINE, SPORTDiscus, and CINAHL databases was performed by 2 independent reviewers. Included articles were obtained from peer-reviewed journals in the English language with no limit for year of publication. Final inclusion criteria required at least 1 of the following outcome variables: pain, injury rate, running economy, joint forces, running velocity, electromyography, muscle performance, or edema. Systematic review. Level 3. Two reviewers appraised each article using the Downs and Black checklist and appraised each for level of evidence. Twenty-three articles met the criteria for this review. Of 27 possible points on the Downs and Black checklist, articles scored between 13 and 19 points, indicating a range of evidence from very limited to moderate. Moderate evidence supports the following biomechanical differences when running barefoot versus in shoes: overall less maximum vertical ground reaction forces, less extension moment and power absorption at the knee, less foot and ankle dorsiflexion at ground contact, less ground contact time, shorter stride length, increased stride frequency, and increased knee flexion at ground contact. Because of lack of high-quality evidence, no definitive conclusions can be drawn regarding specific risks or benefits to running barefoot, shod, or in minimalist shoes.

The effect of mirror therapy integrating functional electrical stimulation on the gait of stroke patients.

PubMed

Ji, Sang-Goo; Cha, Hyun-Gyu; Kim, Myoung-Kwon; Lee, Chang-Ryeol

2014-04-01

[Purpose] The aim of the present study was to examine whether mirror therapy in conjunction with FES in stroke patients can improve gait ability. [Subjects] This study was conducted with 30 subjects who were diagnosed with hemiparesis due to stroke. [Methods] Experimental group I contained 10 subjects who received mirror therapy in conjunction with functional electrical stimulation, experimental group II contained 10 subjects who received mirror therapy, and the control group contained 10 subjects who received a sham therapy. A gait analysis was performed using a three-dimensional motion capture system, which was a real-time tracking device that delivers data in an infrared mode via reflective markers using six cameras. [Results] The results showed a significant difference in gait velocity between groups after the experiment, and post hoc analysis revealed significant differences between experimental group I and the control group and between experimental group II and the control group, respectively. There were also significant differences in step length and stride length between the groups after the experiment, and post hoc analysis revealed significant differences between experimental group I and control group. [Conclusion] The present study showed that mirror therapy in conjunction with FES is more effective for improving gait ability than mirror therapy alone.

Comparative abilities of Microsoft Kinect and Vicon 3D motion capture for gait analysis.

PubMed

Pfister, Alexandra; West, Alexandre M; Bronner, Shaw; Noah, Jack Adam

2014-07-01

Biomechanical analysis is a powerful tool in the evaluation of movement dysfunction in orthopaedic and neurologic populations. Three-dimensional (3D) motion capture systems are widely used, accurate systems, but are costly and not available in many clinical settings. The Microsoft Kinect™ has the potential to be used as an alternative low-cost motion analysis tool. The purpose of this study was to assess concurrent validity of the Kinect™ with Brekel Kinect software in comparison to Vicon Nexus during sagittal plane gait kinematics. Twenty healthy adults (nine male, 11 female) were tracked while walking and jogging at three velocities on a treadmill. Concurrent hip and knee peak flexion and extension and stride timing measurements were compared between Vicon and Kinect™. Although Kinect measurements were representative of normal gait, the Kinect™ generally under-estimated joint flexion and over-estimated extension. Kinect™ and Vicon hip angular displacement correlation was very low and error was large. Kinect™ knee measurements were somewhat better than hip, but were not consistent enough for clinical assessment. Correlation between Kinect™ and Vicon stride timing was high and error was fairly small. Variability in Kinect™ measurements was smallest at the slowest velocity. The Kinect™ has basic motion capture capabilities and with some minor adjustments will be an acceptable tool to measure stride timing, but sophisticated advances in software and hardware are necessary to improve Kinect™ sensitivity before it can be implemented for clinical use.

The hindlimb in walking horses: 1. Kinematics and ground reaction forces.

PubMed

Hodson, E; Clayton, H M; Lanovaz, J L

2001-01-01

The objective was to study associations between kinematics and ground reaction forces in the hindlimb of walking horses. Video (60 Hz) and force (2000 Hz) data were gathered for 8 strides from each of 5 sound horses during the walk. Sagittal plane kinematics were measured concurrently with the vertical and longitudinal ground reaction forces. The hindlimb showed rapid loading and braking in the initial 10% stride. The stifle, tarsal and coffin joints flexed and the fetlock joint extended during this period of rapid loading. The vertical ground reaction force showed 2 peaks separated by a dip; this pattern was similar to the fetlock joint angle-time graph. Peaks in the longitudinal ground reaction force did not appear to correspond with kinematic events. Total braking impulse was equal to total propulsive impulse over the entire stride. Flexion and extension of the hip were responsible for protraction and retraction of the entire limb. Maximal protraction occurred shortly before the end of swing and maximal retraction occurred during breakover. During the middle part of stance the tarsal joint extended slowly, while the stifle began to flex when the limb was retracted beyond the midstance position at 28% stride. Flexion cycles of the stifle and tarsal joints were well coordinated during the swing phase to raise the distal limb as it was protracted. The results demonstrate a relationship between limb kinematics and vertical limb loading in the hindlimbs of sound horses. Future studies will elucidate the alterations in response to lameness.

Leg stiffness and stride frequency in human running.

PubMed

Farley, C T; González, O

1996-02-01

When humans and other mammals run, the body's complex system of muscle, tendon and ligament springs behaves like a single linear spring ('leg spring'). A simple spring-mass model, consisting of a single linear leg spring and a mass equivalent to the animal's mass, has been shown to describe the mechanics of running remarkably well. Force platform measurements from running animals, including humans, have shown that the stiffness of the leg spring remains nearly the same at all speeds and that the spring-mass system is adjusted for higher speeds by increasing the angle swept by the leg spring. The goal of the present study is to determine the relative importance of changes to the leg spring stiffness and the angle swept by the leg spring when humans alter their stride frequency at a given running speed. Human subjects ran on treadmill-mounted force platform at 2.5ms-1 while using a range of stride frequencies from 26% below to 36% above the preferred stride frequency. Force platform measurements revealed that the stiffness of the leg spring increased by 2.3-fold from 7.0 to 16.3 kNm-1 between the lowest and highest stride frequencies. The angle swept by the leg spring decreased at higher stride frequencies, partially offsetting the effect of the increased leg spring stiffness on the mechanical behavior of the spring-mass system. We conclude that the most important adjustment to the body's spring system to accommodate higher stride frequencies is that leg spring becomes stiffer.

Building corporate character. Interview by Nan Stone.

PubMed

Hiatt, A

1992-01-01

Stride Rite is a good company by any definition: Keds, Sperry Top-Siders, and Stride Rite children's shoes are consumer favorites for their fit, quality, and comfort. Wall Street analysts praise the company's outstanding financial performance. Innovative programs such as the first corporate child-care center and public service scholarships support Stride Rite's reputation as one of the most responsible employers and corporate citizens in the United States. Behind Stride Rite's good performance are the building blocks of corporate character: a legacy of quality and service and a leader committed to keeping that legacy lively. When Stride Rite shipped its first children's shoes in 1919, they came with the company's commitment "to produce an honest quality product in an honest way and deliver it as promised." For Arnold Hiatt, that commitment has been the driving force behind the company's evolution from manufacturing into marketing and product development as well as the guiding principle in its relations with consumers, dealers, suppliers, and employees. But Stride Rite's corporate character is also a reflection of Hiatt himself. In his early 20s, Hiatt fled a management training program "designed to make carnivores" out of its new employees and bought Blue Star Shoes, a small manufacturing company that had gone into Chapter 11. Through experience and "stumbling around," he built Blue Star's sales to $5 million-and got a practical education in management, markets, and human nature that has proved equally useful in running Stride Rite.

Changes in Running Mechanics During a 6-Hour Running Race.

PubMed

Giovanelli, Nicola; Taboga, Paolo; Lazzer, Stefano

2017-05-01

To investigate changes in running mechanics during a 6-h running race. Twelve ultraendurance runners (age 41.9 ± 5.8 y, body mass 68.3 ± 12.6 kg, height 1.72 ± 0.09 m) were asked to run as many 874-m flat loops as possible in 6 h. Running speed, contact time (t c ), and aerial time (t a ) were measured in the first lap and every 30 ± 2 min during the race. Peak vertical ground-reaction force (F max ), stride length (SL), vertical downward displacement of the center of mass (Δz), leg-length change (ΔL), vertical stiffness (k vert ), and leg stiffness (k leg ) were then estimated. Mean distance covered by the athletes during the race was 62.9 ± 7.9 km. Compared with the 1st lap, running speed decreased significantly from 4 h 30 min onward (mean -5.6% ± 0.3%, P < .05), while t c increased after 4 h 30 min of running, reaching the maximum difference after 5 h 30 min (+6.1%, P = .015). Conversely, k vert decreased after 4 h, reaching the lowest value after 5 h 30 min (-6.5%, P = .008); t a and F max decreased after 4 h 30 min through to the end of the race (mean -29.2% and -5.1%, respectively, P < .05). Finally, SL decreased significantly (-5.1%, P = .010) during the last hour of the race. Most changes occurred after 4 h continuous self-paced running, suggesting a possible time threshold that could affect performance regardless of absolute running speed.

Changes in spatiotemporal gait parameters following intravenous immunoglobulin treatment for chronic inflammatory demyelinating polyneuropathy.

PubMed

Vo, Mary L; Chin, Russell L; Miranda, Caroline; Latov, Norman

2017-10-01

Gait impairment is a common presenting symptom in patients with chronic inflammatory demyelinating polyneuropathy (CIDP). However, gait parameters have not previously been evaluated in detail as potential independent outcome measures. We prospectively measured changes in spatiotemporal gait parameters of 20 patients with CIDP at baseline and following treatment with intravenous immunoglobulin (IVIG), using GAITRite® a computerized walkway system with embedded sensors. Overall, study patients showed significant improvements in gait velocity, cadence, stride length, double support time, stance phase, and swing phase following IVIG treatment. Mean changes in velocity, stance phase, and swing phase, exhibited the greatest statistical significance among the subgroup that exhibited clinically meaningful improvement in Inflammatory Neuropathy Cause and Treatment disability score, Medical Research Council sum score, and grip strength. Assessment of gait parameters, in particular velocity, step phase and swing phase, is a potentially sensitive outcome measure for evaluating treatment response in CIDP. Muscle Nerve 56: 732-736, 2017. © 2017 Wiley Periodicals, Inc.

Stride lengths, speed and energy costs in walking of Australopithecus afarensis: using evolutionary robotics to predict locomotion of early human ancestors

PubMed Central

Sellers, William I; Cain, Gemma M; Wang, Weijie; Crompton, Robin H

2005-01-01

This paper uses techniques from evolutionary robotics to predict the most energy-efficient upright walking gait for the early human relative Australopithecus afarensis, based on the proportions of the 3.2 million year old AL 288-1 ‘Lucy’ skeleton, and matches predictions against the nearly contemporaneous (3.5–3.6 million year old) Laetoli fossil footprint trails. The technique creates gaits de novo and uses genetic algorithm optimization to search for the most efficient patterns of simulated muscular contraction at a variety of speeds. The model was first verified by predicting gaits for living human subjects, and comparing costs, stride lengths and speeds to experimentally determined values for the same subjects. Subsequent simulations for A. afarensis yield estimates of the range of walking speeds from 0.6 to 1.3 m s−1 at a cost of 7.0 J kg−1 m−1 for the lowest speeds, falling to 5.8 J kg−1 m−1 at 1.0 m s−1, and rising to 6.2 J kg−1 m−1 at the maximum speed achieved. Speeds previously estimated for the makers of the Laetoli footprint trails (0.56 or 0.64 m s−1 for Trail 1, 0.72 or 0.75 m s−1 for Trail 2/3) may have been underestimated, substantially so for Trail 2/3, with true values in excess of 0.7 and 1.0 m s−1, respectively. The predictions conflict with suggestions that A. afarensis used a ‘shuffling’ gait, indicating rather that the species was a fully competent biped. PMID:16849203

The Influence of Audio-Visual Cueing (Traffic Light) on Dual Task Walking in Healthy Older Adults and Older Adults with Balance Impairments.

PubMed

Kaewkaen, Kitchana; Wongsamud, Phongphat; Ngaothanyaphat, Jiratchaya; Supawarapong, Papawarin; Uthama, Suraphong; Ruengsirarak, Worasak; Chanabun, Suthin; Kaewkaen, Pratchaya

2018-02-01

The walking gait of older adults with balance impairment is affected by dual tasking. Several studies have shown that external cues can stimulate improvement in older adults' performance. There is, however, no current evidence to support the usefulness of external cues, such as audio-visual cueing, in dual task walking in older adults. Thus, the aim of this study was to investigate the influence of an audio-visual cue (simulated traffic light) on dual task walking in healthy older adults and in older adults with balance impairments. A two-way repeated measures study was conducted on 14 healthy older adults and 14 older adults with balance impairment, who were recruited from the community in Chiang Rai, Thailand. Their walking performance was assessed using a four-metre walking test at their preferred gait speed and while walking under two further gait conditions, in randomised order: dual task walking and dual task walking with a simulated traffic light. Each participant was tested individually, with the testing taking between 15 and 20 minutes to perform, including two-minute rest periods between walking conditions. Two Kinect cameras recorded the spatio-temporal parameters using MFU gait analysis software. Each participant was tested for each condition twice. The mean parameters for each condition were analysed using a two-way repeated measures analysis of variance (ANOVA) with participant group and gait condition as factors. There was no significant between-group effect for walking speed, stride length and cadence. There were also no significant effects between gait condition and stride length or cadence. However, the effect between gait condition and walking speed was found to be significant [F(1.557, 40.485) = 4.568, P = 0.024, [Formula: see text

Reductions in knee joint forces with weight loss are attenuated by gait adaptations in class III obesity.

PubMed

DeVita, Paul; Rider, Patrick; Hortobágyi, Tibor

2016-03-01

A consensus exists that high knee joint forces are a precursor to knee osteoarthritis and weight loss reduces these forces. Because large weight loss also leads to increased step length and walking velocity, knee contact forces may be reduced less than predicted by the magnitude of weight loss. The purpose was to determine the effects of weight loss on knee muscle and joint loads during walking in Class III obese adults. We determined through motion capture, force platform measures and biomechanical modeling the effects of weight loss produced by gastric bypass surgery over one year on knee muscle and joint loads during walking at a standard, controlled velocity and at self-selected walking velocities. Weight loss equaling 412 N or 34% of initial body weight reduced maximum knee compressive force by 824 N or 67% of initial body weight when walking at the controlled velocity. These changes represent a 2:1 reduction in knee force relative to weight loss when walking velocity is constrained to the baseline value. However, behavioral adaptations including increased stride length and walking velocity in the self-selected velocity condition attenuated this effect by ∼50% leading to a 392 N or 32% initial body weight reduction in compressive force in the knee joint. Thus, unconstrained walking elicited approximately 1:1 ratio of reduction in knee force relative to weight loss and is more indicative of walking behavior than the standard velocity condition. In conclusion, massive weight loss produces dramatic reductions in knee forces during walking but when patients stride out and walk faster, these favorable reductions become substantially attenuated. Copyright © 2016 Elsevier B.V. All rights reserved.

The impact of obesity in the kinematic parameters of gait in young women

PubMed Central

da Silva-Hamu, Tânia Cristina Dias; Formiga, Cibelle Kayenne Martins Roberto; Gervásio, Flávia Martins; Ribeiro, Darlan Martins; Christofoletti, Gustavo; de França Barros, Jônatas

2013-01-01

Background The prevalence of obesity is increasing in the population, particularly in women. Obesity has an impact on the musculoskeletal system, leading to knee and ankle overexertion, difficulty with balance, and functional disability. The aim of this study was to identify changes in kinematic parameters of gait in obese young women. Methods A case-control study with 24 obese women (mean age 35.20 ± 9.9 years and mean body mass index of 31.85 ± 2.94 kg/m2) and 24 eutrophic women (mean age of 36.33 ± 11.14 and mean body mass index of 21.82 ± 1.58 kg/m2). The gait of women was evaluated by the system Vicon Motus® 9.2. The linear parameters of speed, cadence, right and left step, and stride lengths were studied, as well as the angular parameters of knee and ankle. Results There was a decrease in linear gait parameters (P < 0.001), speed, cadence, right and left step, and stride lengths. In regard to the angular parameters of the knee and ankle, there were also differences between the analyses (P < 0.001). At the knee joint, obese women have delayed onset of the second wave of flexion, exacerbating such movement in order to compensate. In regard to the ankle, both groups showed curves of normal plantar flexion and dorsiflexion, but there was a delay in the path graph in the ankle of obese women indicating a reduced range of motion and possible over-exertion of the pretibial muscles and soleus muscles simultaneously. Conclusion The results of this study revealed that obesity is a factor that negatively influences the kinematic parameters of gait of young women. PMID:23837005

Association between gait characteristics and endothelial oxidative stress and inflammation in patients with symptomatic peripheral artery disease.

PubMed

Gardner, Andrew W; Montgomery, Polly S; Casanegra, Ana I; Silva-Palacios, Federico; Ungvari, Zoltan; Csiszar, Anna

2016-06-01

The aim of the study was to determine whether gait characteristics were associated with endothelial cell inflammation, oxidative stress, and apoptosis and with circulating biomarkers of inflammation and antioxidant capacity in older patients with symptomatic peripheral artery disease (PAD). Gait measurements of 231 symptomatic men and women with PAD were assessed during a 4-m walk test. Patients were further characterized on endothelial effects of circulating factors present in the sera using a cell culture-based bioassay on primary human arterial endothelial cells and on circulating inflammatory and vascular biomarkers. In a multivariate regression model for gait speed, the significant independent variables were age (p < 0.001), intercellular cell adhesion molecule-1 (ICAM-1) (p < 0.001), diabetes (p = 0.003), sex (p = 0.003), and history of cerebrovascular accidents (p = 0.021). In multivariate analyses for gait cadence, the significant independent predictors included high-sensitivity C-reactive protein (HsCRP) (p < 0.001), diabetes (p = 0.001), and hypertension (p = 0.001). In a multivariate regression model for gait stride length, the significant independent variables were HsCRP (p < 0.001), age (p < 0.001), ICAM-1 (p < 0.001), hypertension (p = 0.002), cellular reactive oxygen species production (p = 0.007), and sex (p = 0.008). Higher levels of circulating biomarkers of inflammation and endothelial cell oxidative stress were associated with slower gait speed, slower cadence, and shorter stride length in older symptomatic patients with PAD. Additionally, this profile of impaired gait was more evident in older patients, in women, and in those with diabetes, hypertension, and history of cerebrovascular accidents.

Kinematic and ground reaction force accommodation during weighted walking.

PubMed

James, C Roger; Atkins, Lee T; Yang, Hyung Suk; Dufek, Janet S; Bates, Barry T

2015-12-01

Weighted walking is a functional activity common in daily life and can influence risks for musculoskeletal loading, injury and falling. Much information exists about weighted walking during military, occupational and recreational tasks, but less is known about strategies used to accommodate to weight carriage typical in daily life. The purposes of the study were to examine the effects of weight carriage on kinematics and peak ground reaction force (GRF) during walking, and explore relationships between these variables. Twenty subjects walked on a treadmill while carrying 0, 44.5 and 89 N weights in front of the body. Peak GRF, sagittal plane joint/segment angular kinematics, stride length and center of mass (COM) vertical displacement were measured. Changes in peak GRF and displacement variables between weight conditions represented accommodation. Effects of weight carriage were tested using analysis of variance. Relationships between peak GRF and kinematic accommodation variables were examined using correlation and regression. Subjects were classified into sub-groups based on peak GRF responses and the correlation analysis was repeated. Weight carriage increased peak GRF by an amount greater than the weight carried, decreased stride length, increased vertical COM displacement, and resulted in a more extended and upright posture, with less hip and trunk displacement during weight acceptance. A GRF increase was associated with decreases in hip extension (|r|=.53, p=.020) and thigh anterior rotation (|r|=.57, p=.009) displacements, and an increase in foot anterior rotation displacement (|r|=.58, p=.008). Sub-group analysis revealed that greater GRF increases were associated with changes at multiple sites, while lesser GRF increases were associated with changes in foot and trunk displacement. Weight carriage affected walking kinematics and revealed different accommodation strategies that could have implications for loading and stability. Copyright © 2015 Elsevier B.V. All rights reserved.

Microsoft Kinect can distinguish differences in over-ground gait between older persons with and without Parkinson's disease.

PubMed

Eltoukhy, Moataz; Kuenze, Christopher; Oh, Jeonghoon; Jacopetti, Marco; Wooten, Savannah; Signorile, Joseph

2017-06-01

Gait patterns differ between healthy elders and those with Parkinson's disease (PD). A simple, low-cost clinical tool that can evaluate kinematic differences between these populations would be invaluable diagnostically; since gait analysis in a clinical setting is impractical due to cost and technical expertise. This study investigated the between group differences between the Kinect and a 3D movement analysis system (BTS) and reported validity and reliability of the Kinect v2 sensor for gait analysis. Nineteen subjects participated, eleven without (C) and eight with PD (PD). Outcome measures included spatiotemporal parameters and kinematics. Ankle range of motion for C was significantly less during ankle swing compared to PD (p=0.04) for the Kinect. Both systems showed significant differences for stride length (BTS (C 1.24±0.16, PD=1.01±0.17, p=0.009), Kinect (C=1.24±0.17, PD=1.00±0.18, p=0.009)), gait velocity (BTS (C=1.06±0.14, PD=0.83±0.15, p=0.01), Kinect (C=1.06±0.15, PD=0.83±0.16, p=0.01)), and swing velocity (BTS (C=2.50±0.27, PD=2.12±0.36, p=0.02), Kinect (C=2.32±0.25, PD=1.95±0.31, p=0.01)) between groups. Agreement (Range ICC =0.93-0.99) and consistency (Range ICC =0.94-0.99) were excellent between systems for stride length, stance duration, swing duration, gait velocity, and swing velocity. The Kinect v2 can was sensitive enough to detect between group differences and consistently produced results similar to the BTS system. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

The influence of divided attention on walking turns: Effects on gait control in young adults with and without a history of low back pain.

PubMed

Smith, Jo Armour; Gordon, James; Kulig, Kornelia

2017-10-01

The cognitive control of gait is altered in individuals with low back pain, but it is unclear if this alteration persists between painful episodes. Locomotor perturbations such as walking turns may provide a sensitive measure of gait adaptation during divided attention in young adults. The purpose of this study was to investigate changes in gait during turns performed with divided attention, and to compare healthy young adults with asymptomatic individuals who have a history of recurrent low back pain (rLBP). Twenty-eight participants performed 90° ipsilateral walking turns at a controlled speed of 1.5m/s. During the divided attention condition they concurrently performed a verbal 2-back task. Step length and width, trunk-pelvis and hip excursion, inter-segmental coordination and stride-to-stride variability were quantified using motion capture. Mixed-model ANOVA were used to examine the effect of divided attention and group, and interaction effects on the selected variables. Step length variability decreased significantly with divided attention in the healthy group but not in the rLBP group (post-hoc p=0.024). Inter-segmental coordination variability was significantly decreased during divided attention (main effect of condition p <0.000). There were small but significant reductions in hip axial and sagittal motion across groups (main effect of condition p=0.044 and p=0.040 respectively), and a trend toward increased frontal motion in the rLBP group only (post-hoc p=0.048). These findings suggest that the ability to switch attentional resources during gait is altered in young adults with a history of rLBP, even between symptomatic episodes. Copyright © 2017 Elsevier B.V. All rights reserved.

Superficial plantar cutaneous sensation does not trigger barefoot running adaptations.

PubMed

Thompson, M A; Hoffman, K M

2017-09-01

It has long been proposed that the gait alterations associated with barefoot running are mediated by alterations in sensory feedback, yet there has been no data to support this claim. Thus, the purpose of this study was to examine the role of superficial plantar cutaneous feedback in barefoot and shod running. 10 healthy active subjects (6 male, 4 female); mass: 65.2+9.7kg; age: 27+7.1years participated in this study. 10 over-ground running trials were completed in each of the following conditions: barefoot (BF), shod (SHOD), anesthetized barefoot (ANEST BF) and anesthetized shod (ANEST SHOD). For the anesthetized conditions 0.1-0.3mL of 1% lidocaine was injected into the dermal layer of the plantar foot below the metatarsal heads, lateral column and heel. 3-dimensional motion analysis and ground reaction force (GRF) data were captured as subjects ran over a 20m runway with a force plate at 12m. Kinematic and kinetic differences were analyzed via two-way repeated measure ANOVAs. The differences in gait between the BF and SHOD conditions were consistent with previous research, with subjects exhibiting a significant decrease in stride length and changing from rearfoot strike when SHOD to fore/midfoot strike when BF. Additionally, BF running was associated with decreased impact peak magnitudes and peak vertical GRFs. Despite anesthetizing the plantar surface, there was no difference between the BF and ANEST BF conditions in terms of stride length, foot strike or GRFs. Superficial cutaneous sensory receptors are not primarily responsible for the gait changes associated with barefoot running. Copyright © 2017 Elsevier B.V. All rights reserved.

Insights into gait disorders: walking variability using phase plot analysis, Parkinson's disease.

PubMed

Esser, Patrick; Dawes, Helen; Collett, Johnny; Howells, Ken

2013-09-01

Gait variability may have greater utility than spatio-temporal parameters and can, be an indication for risk of falling in people with Parkinson's disease (PD). Current methods rely on prolonged data collection in order to obtain large datasets which may be demanding to obtain. We set out to explore a phase plot variability analysis to differentiate typically developed adults (TDAs) from PD obtained from two 10 m walks. Fourteen people with PD and good mobility (Rivermead Mobility Index≥8) and ten aged matched TDA were recruited and walked over 10-m at self-selected walking speed. An inertial measurement unit was placed over the projected centre of mass (CoM) sampling at 100 Hz. Vertical CoM excursion was derived to determine modelled spatiotemporal data after which the phase plot analysis was applied producing a cloud of datapoints. SDA described the spread and SDB the width of the cloud with β the angular vector of the data points. The ratio (∀) was defined as SDA: SDB. Cadence (p=.342) and stride length (p=.615) did not show a significance between TDA and PD. A difference was found for walking speed (p=.041). Furthermore a significant difference was found for β (p=.010), SDA (p=.004) other than SDB (p=.385) or ratio ∀ (p=.830). Two sequential 10-m walks showed no difference in PD for cadence (p=.193), stride length (p=.683), walking speed (p=.684) and β (p=.194), SDA (p=.051), SDB (p=.145) or ∀ (p=.226). The proposed phase plot analysis, performed on CoM motion could be used to reliably differentiate PD from TDA over a 10-m walk. Copyright © 2013 Elsevier B.V. All rights reserved.

Understanding the Relationship between Type 2 Diabetes Mellitus and Falls in Older Adults: A Prospective Cohort Study

PubMed Central

Roman de Mettelinge, Tine; Cambier, Dirk; Calders, Patrick; Van Den Noortgate, Nele; Delbaere, Kim

2013-01-01

Background Older adults with type 2 Diabetes Mellitus are at increased risk of falling. The current study aims to identify risk factors that mediate the relationship between diabetes and falls. Methods 199 older adults (104 with diabetes and 95 healthy controls) underwent a medical screening. Gait (GAITRite®), balance (AccuGait® force plate), grip strength (Jamar®), and cognitive status (Mini-Mental State Examination and Clock Drawing Test) were assessed. Falls were prospectively recorded during a 12-month follow-up period using monthly calendars. Results Compared to controls, diabetes participants scored worse on all physical and cognitive measures. Sixty-four participants (42 diabetes vs. 22 controls) reported at least one injurious fall or two non-injurious falls (“fallers”). Univariate logistic regression identified diabetes as a risk factor for future falls (Odds Ratio 2.25, 95%CI 1.21–4.15, p = 0.010). Stepwise multiple regressions defined diabetes and poor balance as independent risk factors for falling. Taking more medications, slower walking speed, shorter stride length and poor cognitive performance were mediators that reduced the Odds Ratio of the relationship between diabetes and faller status relationship the most followed by reduced grip strength and increased stride length variability. Conclusions Diabetes is a major risk factor for falling, even after controlling for poor balance. Taking more medications, poorer walking performance and reduced cognitive functioning were mediators of the relationship between diabetes and falls. Tailored preventive programs including systematic medication reviews, specific balance exercises and cognitive training might be beneficial in reducing fall risk in older adults suffering from diabetes. PMID:23825617

Comparison of Minimalist Footwear Strategies for Simulating Barefoot Running: A Randomized Crossover Study

PubMed Central

Hollander, Karsten; Argubi-Wollesen, Andreas; Reer, Rüdiger; Zech, Astrid

2015-01-01

Possible benefits of barefoot running have been widely discussed in recent years. Uncertainty exists about which footwear strategy adequately simulates barefoot running kinematics. The objective of this study was to investigate the effects of athletic footwear with different minimalist strategies on running kinematics. Thirty-five distance runners (22 males, 13 females, 27.9 ± 6.2 years, 179.2 ± 8.4 cm, 73.4 ± 12.1 kg, 24.9 ± 10.9 km.week-1) performed a treadmill protocol at three running velocities (2.22, 2.78 and 3.33 m.s-1) using four footwear conditions: barefoot, uncushioned minimalist shoes, cushioned minimalist shoes, and standard running shoes. 3D kinematic analysis was performed to determine ankle and knee angles at initial foot-ground contact, rate of rear-foot strikes, stride frequency and step length. Ankle angle at foot strike, step length and stride frequency were significantly influenced by footwear conditions (p<0.001) at all running velocities. Posthoc pairwise comparisons showed significant differences (p<0.001) between running barefoot and all shod situations as well as between the uncushioned minimalistic shoe and both cushioned shoe conditions. The rate of rear-foot strikes was lowest during barefoot running (58.6% at 3.33 m.s-1), followed by running with uncushioned minimalist shoes (62.9%), cushioned minimalist (88.6%) and standard shoes (94.3%). Aside from showing the influence of shod conditions on running kinematics, this study helps to elucidate differences between footwear marked as minimalist shoes and their ability to mimic barefoot running adequately. These findings have implications on the use of footwear applied in future research debating the topic of barefoot or minimalist shoe running. PMID:26011042

Comparison of minimalist footwear strategies for simulating barefoot running: a randomized crossover study.

PubMed

Hollander, Karsten; Argubi-Wollesen, Andreas; Reer, Rüdiger; Zech, Astrid

2015-01-01

Possible benefits of barefoot running have been widely discussed in recent years. Uncertainty exists about which footwear strategy adequately simulates barefoot running kinematics. The objective of this study was to investigate the effects of athletic footwear with different minimalist strategies on running kinematics. Thirty-five distance runners (22 males, 13 females, 27.9 ± 6.2 years, 179.2 ± 8.4 cm, 73.4 ± 12.1 kg, 24.9 ± 10.9 km x week(-1)) performed a treadmill protocol at three running velocities (2.22, 2.78 and 3.33 m x s(-1)) using four footwear conditions: barefoot, uncushioned minimalist shoes, cushioned minimalist shoes, and standard running shoes. 3D kinematic analysis was performed to determine ankle and knee angles at initial foot-ground contact, rate of rear-foot strikes, stride frequency and step length. Ankle angle at foot strike, step length and stride frequency were significantly influenced by footwear conditions (p<0.001) at all running velocities. Posthoc pairwise comparisons showed significant differences (p<0.001) between running barefoot and all shod situations as well as between the uncushioned minimalistic shoe and both cushioned shoe conditions. The rate of rear-foot strikes was lowest during barefoot running (58.6% at 3.33 m x s(-1)), followed by running with uncushioned minimalist shoes (62.9%), cushioned minimalist (88.6%) and standard shoes (94.3%). Aside from showing the influence of shod conditions on running kinematics, this study helps to elucidate differences between footwear marked as minimalist shoes and their ability to mimic barefoot running adequately. These findings have implications on the use of footwear applied in future research debating the topic of barefoot or minimalist shoe running.

Community Literacy at Work with STRIDE (Success Through Reading Improvement and DEvelopment): Overview of a Successful Community Literacy Program.

ERIC Educational Resources Information Center

Macy, Rita

STRIDE (Success Through Reading Improvement and DEvelopment) is a literacy program developed in 1986 by Crowder College, located in the rural Ozarks of southwestern Missouri. Serving all age groups with trained literacy tutors ranging in age from 11 to over 60, STRIDE has been built on five main activities: (1) develop a philosophy that is…

Evolution of the human hip. Part 1: the osseous framework

PubMed Central

Hogervorst, Tom; Vereecke, Evie E.

2014-01-01

Extensive osseous adaptations of the lumbar spine, pelvis, hip and femur characterize the emergence of the human bipedal gait with its ‘double extension’ of the lumbar spine and hip. To accommodate lumbar lordosis, the pelvis was ‘compacted’, becoming wider and shorter, as compared with the non-human apes. The hip joint acquired a much more extended position, which can be seen in a broader evolutionary context of verticalization of limbs. When loaded in a predominantly vertical position, the femur can be built lighter and longer than when it is loaded more horizontally because bending moments are smaller. Extension of the hip joint together with elongation of the femur increases effective leg length, and hence stride length, which improves energy efficiency. At the hip joint itself, the shift of the hip’s default working range to a more extended position influences concavity at the head–neck junction and femoral neck anteversion. PMID:27011802

Evolution of the human hip. Part 1: the osseous framework.

PubMed

Hogervorst, Tom; Vereecke, Evie E

2014-10-01

Extensive osseous adaptations of the lumbar spine, pelvis, hip and femur characterize the emergence of the human bipedal gait with its 'double extension' of the lumbar spine and hip. To accommodate lumbar lordosis, the pelvis was 'compacted', becoming wider and shorter, as compared with the non-human apes. The hip joint acquired a much more extended position, which can be seen in a broader evolutionary context of verticalization of limbs. When loaded in a predominantly vertical position, the femur can be built lighter and longer than when it is loaded more horizontally because bending moments are smaller. Extension of the hip joint together with elongation of the femur increases effective leg length, and hence stride length, which improves energy efficiency. At the hip joint itself, the shift of the hip's default working range to a more extended position influences concavity at the head-neck junction and femoral neck anteversion.

Using an electrohydraulic ankle foot orthosis to study modifications in feedforward control during locomotor adaptation to force fields applied in stance

PubMed Central

Noel, Martin; Fortin, Karine; Bouyer, Laurent J

2009-01-01

Background Adapting to external forces during walking has been proposed as a tool to improve locomotion after central nervous system injury. However, sensorimotor integration during walking varies according to the timing in the gait cycle, suggesting that adaptation may also depend on gait phases. In this study, an ElectroHydraulic AFO (EHO) was used to apply forces specifically during mid-stance and push-off to evaluate if feedforward movement control can be adapted in these 2 gait phases. Methods Eleven healthy subjects walked on a treadmill before (3 min), during (5 min) and after (5 min) exposure to 2 force fields applied by the EHO (mid-stance/push-off; ~10 Nm, towards dorsiflexion). To evaluate modifications in feedforward control, strides with no force field ('catch strides') were unexpectedly inserted during the force field walking period. Results When initially exposed to a mid-stance force field (FF20%), subjects showed a significant increase in ankle dorsiflexion velocity. Catches applied early into the FF20% were similar to baseline (P > 0.99). Subjects gradually adapted by returning ankle velocity to baseline over ~50 strides. Catches applied thereafter showed decreased ankle velocity where the force field was normally applied, indicating the presence of feedforward adaptation. When initially exposed to a push-off force field (FF50%), plantarflexion velocity was reduced in the zone of force field application. No adaptation occurred over the 5 min exposure. Catch strides kinematics remained similar to control at all times, suggesting no feedforward adaptation. As a control, force fields assisting plantarflexion (-3.5 to -9.5 Nm) were applied and increased ankle plantarflexion during push-off, confirming that the lack of kinematic changes during FF50% catch strides were not simply due to a large ankle impedance. Conclusion Together these results show that ankle exoskeletons such as the EHO can be used to study phase-specific adaptive control of the ankle during locomotion. Our data suggest that, for short duration exposure, a feedforward modification in torque output occurs during mid-stance but not during push-off. These findings are important for the design of novel rehabilitation methods, as they suggest that the ability to use resistive force fields for training may depend on targeted gait phases. PMID:19493356

Using an electrohydraulic ankle foot orthosis to study modifications in feedforward control during locomotor adaptation to force fields applied in stance.

PubMed

Noel, Martin; Fortin, Karine; Bouyer, Laurent J

2009-06-03

Adapting to external forces during walking has been proposed as a tool to improve locomotion after central nervous system injury. However, sensorimotor integration during walking varies according to the timing in the gait cycle, suggesting that adaptation may also depend on gait phases. In this study, an ElectroHydraulic AFO (EHO) was used to apply forces specifically during mid-stance and push-off to evaluate if feedforward movement control can be adapted in these 2 gait phases. Eleven healthy subjects walked on a treadmill before (3 min), during (5 min) and after (5 min) exposure to 2 force fields applied by the EHO (mid-stance/push-off; approximately 10 Nm, towards dorsiflexion). To evaluate modifications in feedforward control, strides with no force field ('catch strides') were unexpectedly inserted during the force field walking period. When initially exposed to a mid-stance force field (FF 20%), subjects showed a significant increase in ankle dorsiflexion velocity. Catches applied early into the FF 20% were similar to baseline (P > 0.99). Subjects gradually adapted by returning ankle velocity to baseline over approximately 50 strides. Catches applied thereafter showed decreased ankle velocity where the force field was normally applied, indicating the presence of feedforward adaptation. When initially exposed to a push-off force field (FF 50%), plantarflexion velocity was reduced in the zone of force field application. No adaptation occurred over the 5 min exposure. Catch strides kinematics remained similar to control at all times, suggesting no feedforward adaptation. As a control, force fields assisting plantarflexion (-3.5 to -9.5 Nm) were applied and increased ankle plantarflexion during push-off, confirming that the lack of kinematic changes during FF 50% catch strides were not simply due to a large ankle impedance. Together these results show that ankle exoskeletons such as the EHO can be used to study phase-specific adaptive control of the ankle during locomotion. Our data suggest that, for short duration exposure, a feedforward modification in torque output occurs during mid-stance but not during push-off. These findings are important for the design of novel rehabilitation methods, as they suggest that the ability to use resistive force fields for training may depend on targeted gait phases.

The use of MP3 recorders to log data from equine hoof mounted accelerometers.

PubMed

Parsons, K J; Wilson, A M

2006-11-01

MP3 recorders are readily available, small, lightweight and low cost, providing the potential for logging analogue hoof mounted accelerometer signals for the characterisation of equine locomotion. These, however, require testing in practice. To test whether 1) multiple MP3 recorders can maintain synchronisation, giving the ability to synchronise independent recorders for the logging of multiple limbs simultaneously; and 2) features of a foot mounted accelerometer signal attributable to foot-on and foot-off can be accurately identified from horse foot mounted accelerometers logged directly into an MP3 recorder. Three experiments were performed: 1) Maintenance of synchronisation was assessed by counting the number of samples recorded by each of 4 MP3 recorders while mounted on a trotting horse and over 2 consecutive 30 min periods in 8 recorders on a bench. 2) Foot-on and foot-off times obtained from manual transcription of MP3 logged data and directly logged accelerometer signal were compared. 3) MP3/accelerometer acquisition units were used to log accelerometer signals from racehorses during extended training sessions. Mean absolute error of synchronisation between MP3 recorders was 10 samples per million (compared to mean number of samples, range 1-32 samples per million). Error accumulation showed a linear correlation with time. Features attributable to foot on and foot off were equally identifiable from the MP3 recorded signal over a range of equine gaits. Multiple MP3 recorders can be synchronised and used as a relatively cheap, robust, reliable and accurate logging system when combined with an accelerometer and external battery for the specific application of the measurement of stride timing variables across the range of equine gaits during field locomotion. Footfall timings can be used to identify intervals between the fore and hind contacts, the identification of diagonal advanced placement and to calculate stride timing variables (stance time, protraction time and stride time). These parameters are invaluable for the characterisation and assessment of equine locomotion.

Locomotor-respiratory coupling patterns and oxygen consumption during walking above and below preferred stride frequency.

PubMed

O'Halloran, Joseph; Hamill, Joseph; McDermott, William J; Remelius, Jebb G; Van Emmerik, Richard E A

2012-03-01

Locomotor respiratory coupling patterns in humans have been assessed on the basis of the interaction between different physiological and motor subsystems; these interactions have implications for movement economy. A complex and dynamical systems framework may provide more insight than entrainment into the variability and adaptability of these rhythms and their coupling. The purpose of this study was to investigate the relationship between steady state locomotor-respiratory coordination dynamics and oxygen consumption [Formula: see text] of the movement by varying walking stride frequency from preferred. Twelve male participants walked on a treadmill at a self-selected speed. Stride frequency was varied from -20 to +20% of preferred stride frequency (PSF) while respiratory airflow, gas exchange variables, and stride kinematics were recorded. Discrete relative phase and return map techniques were used to evaluate the strength, stability, and variability of both frequency and phase couplings. Analysis of [Formula: see text] during steady-state walking showed a U-shaped response (P = 0.002) with a minimum at PSF and PSF - 10%. Locomotor-respiratory frequency coupling strength was not greater (P = 0.375) at PSF than any other stride frequency condition. The dominant coupling across all conditions was 2:1 with greater occurrences at the lower stride frequencies. Variability in coupling was the greatest during PSF, indicating an exploration of coupling strategies to search for the coupling frequency strategy with the least oxygen consumption. Contrary to the belief that increased strength of frequency coupling would decrease oxygen consumption; these results conclude that it is the increased variability of frequency coupling that results in lower oxygen consumption.

Changes in Lower Extremity Kinematics and Temporal Parameters of Adolescent Baseball Pitchers During an Extended Pitching Bout.

PubMed

Kung, Stacey M; Shultz, Sarah P; Kontaxis, Andreas; Kraszewski, Andrew P; Gibbons, Mandi W; Backus, Sherry I; Fink, Philip W; Fealy, Stephen; Hillstrom, Howard J

2017-04-01

Few studies have investigated detailed 3-dimensional lower extremity kinematics during baseball pitching in adolescent athletes during extended play. Changes in these parameters may affect performance outcomes. To investigate whether adolescent baseball pitchers experience changes in lower extremity kinematics and event timing during a simulated game-length pitching bout. Descriptive laboratory study. Twelve male adolescent pitchers (aged 14-16 years) threw 6 sets of 15 fastball pitches from an artificial pitching mound to a target at regulation distance. Joint angles and angular velocities at the hip, knee, and ankle of both legs were collected throughout the phases of the pitching cycle as well as stride length, pelvis orientation, pitch duration, timing of foot contact and ball release, ball speed, and pitching accuracy. Paired t tests ( P < .05) were used to compare the dependent variables between the last 5 pitches of the second (baseline) and sixth (final) sets. During the stride phase, decreased maximum angular excursions for hip extension (baseline: 14.7° ± 9.8°; final: 11.6° ± 10.3°; P < .05) and ankle plantar flexion (baseline: 30.2° ± 14.5°; final: 24.2° ± 15.3°; P < .05) as well as maximum angular velocity for knee extension (baseline: 144.9 ± 63.3 deg·s -1 ; final: 121.7 ± 62.0 deg·s -1 ; P < .05) were observed between sets in the trailing leg. At foot contact, pitchers had decreased hip flexion (baseline: 69.5° ± 10.1°; final: 66.5° ± 11.8°; P < .05) and increased hip abduction (baseline: 20.7° ± 8.9°; final: 25.4° ± 6.0°; P < .05) in the leading leg in the final set. Compared with the baseline set, ball speed significantly decreased in the final set (29.5 ± 2.5 m·s -1 vs 28.3 ± 2.5 m·s -1 , respectively; P < .05). Kinematic changes and decreased ball speeds observed in the final set suggest that adolescent pitchers are unable to maintain lower extremity kinematics and performance as a result of extended play. The results from this study may warrant further investigation into how altered lower extremity kinematics may affect trunk and upper extremity function, performance, and risk of injuries during pitching in adolescent athletes, particularly during actual game play.

Entrainment to a real time fractal visual stimulus modulates fractal gait dynamics.

PubMed

Rhea, Christopher K; Kiefer, Adam W; D'Andrea, Susan E; Warren, William H; Aaron, Roy K

2014-08-01

Fractal patterns characterize healthy biological systems and are considered to reflect the ability of the system to adapt to varying environmental conditions. Previous research has shown that fractal patterns in gait are altered following natural aging or disease, and this has potential negative consequences for gait adaptability that can lead to increased risk of injury. However, the flexibility of a healthy neurological system to exhibit different fractal patterns in gait has yet to be explored, and this is a necessary step toward understanding human locomotor control. Fifteen participants walked for 15min on a treadmill, either in the absence of a visual stimulus or while they attempted to couple the timing of their gait with a visual metronome that exhibited a persistent fractal pattern (contained long-range correlations) or a random pattern (contained no long-range correlations). The stride-to-stride intervals of the participants were recorded via analog foot pressure switches and submitted to detrended fluctuation analysis (DFA) to determine if the fractal patterns during the visual metronome conditions differed from the baseline (no metronome) condition. DFA α in the baseline condition was 0.77±0.09. The fractal patterns in the stride-to-stride intervals were significantly altered when walking to the fractal metronome (DFA α=0.87±0.06) and to the random metronome (DFA α=0.61±0.10) (both p<.05 when compared to the baseline condition), indicating that a global change in gait dynamics was observed. A variety of strategies were identified at the local level with a cross-correlation analysis, indicating that local behavior did not account for the consistent global changes. Collectively, the results show that a gait dynamics can be shifted in a prescribed manner using a visual stimulus and the shift appears to be a global phenomenon. Copyright © 2014 Elsevier B.V. All rights reserved.

Effect of rivastigmine on mobility of patients with higher-level gait disorder: a pilot exploratory study.

PubMed

Gurevich, Tanya; Balash, Yacov; Merims, Doron; Peretz, Chava; Herman, Talia; Hausdorff, Jeffrey M; Giladi, Nir

2014-06-01

Higher-level gait disorder (HLGD) in older adults is characterized by postural instability, stepping dysrhythmicity, recurrent falls and progressive immobility. Cognitive impairments are frequently associated with HLGD. The aim of this study was to compare gait and cognitive performance before and after the use of rivastigmine in patients with HLGD, free from cognitive impairment or Parkinsonism. Fifteen non-demented patients with HLGD (age 79.2 ± 5.9 years; 11 women; Mini-Mental State Examination [MMSE] 28.3 ± 1.4) received escalating doses of rivastigmine for 12 weeks in an open-label, pilot study. They were assessed before and after treatment (week 0 and week 12), and after a 4-week washout period (week 16). Assessments included the Mindstreams computerized neuropsychological battery, Activities-specific Balance Confidence Scale, State-Trait Anxiety Inventory, Geriatric Depression Scale, Timed Up and Go (TUG) test, gait speed and stride time variability. One-way multiple analysis of variance tests for repeated measures were used, and Pillai's trace test was considered as robust to investigate significant differences. The mean dose of rivastigmine during the 8-12 week period was 5.1 ± 2.3 mg/day. A positive effect was observed on the Mindstreams memory subscale and anxiety scores [Pillai's trace: F(6,724) = 0.508, p = 0.010; and F(7,792) = 0.545, p = 0.006, respectively, over the course of the study] as well as on mobility (TUG test) [Pillai's trace: F(4,863) = 0.448; p = 0.028], whereas gait speed and stride time variability did not change. The use of relatively low-dose rivastigmine did not affect gait speed and stride time variability; however, the general mobility and anxiety were improved. These preliminary results warrant a larger, randomized, placebo-controlled study.

Older adults adopted more cautious gait patterns when walking in socks than barefoot.

PubMed

Tsai, Yi-Ju; Lin, Sang-I

2013-01-01

Walking barefoot or in socks is common for ambulating indoors and has been reported to be associated with increased risk of falls and related injuries in the elderly. This study sought to determine if gait patterns differed between these two conditions for young and older adults. A motion analysis system was used to record and calculate the stride characteristics and motion of the body's center of mass (COM) of 21 young and 20 older adults. For the walking tasks, the participants walked on a smooth floor surface at their preferred speed either barefoot or in socks in a random order. The socks were commercially available and commonly used. The results demonstrated that while walking in socks, compared with walking barefoot, older adults adopted a more cautious gait pattern including decreased walking speed and shortened stride length as well as reduced COM minimal velocity during the single limb support phase. Young adults, however, did not demonstrate significant changes. These findings suggest that walking with socks might present a greater balance threat for older adults. Clinically, safety precautions about walking in socks should be considered to be given to older adults, especially those with balance deficits. Copyright © 2012 Elsevier B.V. All rights reserved.

Analysis of lower limb work-energy patterns in world-class race walkers.

PubMed

Hanley, Brian; Bissas, Athanassios

2017-05-01

The aim of this study was to analyse lower limb work patterns in world-class race walkers. Seventeen male and female athletes race walked at competitive pace. Ground reaction forces (1000 Hz) and high-speed videos (100 Hz) were recorded and normalised joint moments, work and power, stride length, stride frequency and speed estimated. The hip flexors and extensors were the main generators of energy (24.5 J (±6.9) and 40.3 J (±8.3), respectively), with the ankle plantarflexors (16.3 J (±4.3)) contributing to the energy generated during late stance. The knee generated little energy but performed considerable negative work during swing (-49.1 J (±8.7)); the energy absorbed by the knee extensors was associated with smaller changes in velocity during stance (r = .783, P < .001), as was the energy generated by the hip flexors (r = -.689, P = .002). The knee flexors did most negative work (-38.6 J (±5.8)) and the frequent injuries to the hamstrings are probably due to this considerable negative work. Coaches should note the important contributions of the hip and ankle muscles to energy generation and the need to develop knee flexor strength in reducing the risk of injury.

Gait assessment in mild cognitive impairment and Alzheimer's disease: the effect of dual-task challenges across the cognitive spectrum.

PubMed

Muir, Susan W; Speechley, Mark; Wells, Jennie; Borrie, Michael; Gopaul, Karen; Montero-Odasso, Manuel

2012-01-01

Gait impairment is a prominent falls risk factor and a prevalent feature among older adults with cognitive impairment. However, there is a lack of comparative studies on gait performance and fall risk covering the continuum from normal cognition through mild cognitive impairment (MCI) to Alzheimer's disease (AD). We evaluated gait performance and the response to dual-task challenges in older adults with AD, MCI and normal cognition without a history of falls. We hypothesized that, in older people without history of falls, gait performance will deteriorate across the cognitive spectrum with changes being more evident under dual-tasking. Gait was assessed using an electronic walkway under single and three dual-tasks conditions. Gait velocity and stride time variability were not significantly different between the three groups under the single-task condition. By contrast, significant differences of decreasing velocity (p<0.0001), increasing stride time (p=0.0057) and increasing stride time variability (p=0.0037) were found under dual-task testing for people with MCI and AD. Less automatic and more complex dual-task tests, such as naming animals and serial subtraction by sevens from 100, created the greatest deterioration of gait performance. Gait changes under dual-tasking for the MCI and AD groups were statistically different from the cognitively normal controls. Dual-task assessment exposed gait impairments not obvious under a single-task test condition and may facilitate falls risk identification in cognitively impaired persons without a history of falls. Copyright © 2011 Elsevier B.V. All rights reserved.

Reliability of segmental accelerations measured using a new wireless gait analysis system.

PubMed

Kavanagh, Justin J; Morrison, Steven; James, Daniel A; Barrett, Rod

2006-01-01

The purpose of this study was to determine the inter- and intra-examiner reliability, and stride-to-stride reliability, of an accelerometer-based gait analysis system which measured 3D accelerations of the upper and lower body during self-selected slow, preferred and fast walking speeds. Eight subjects attended two testing sessions in which accelerometers were attached to the head, neck, lower trunk, and right shank. In the initial testing session, two different examiners attached the accelerometers and performed the same testing procedures. A single examiner repeated the procedure in a subsequent testing session. All data were collected using a new wireless gait analysis system, which features near real-time data transmission via a Bluetooth network. Reliability for each testing condition (4 locations, 3 directions, 3 speeds) was quantified using a waveform similarity statistic known as the coefficient of multiple determination (CMD). CMD's ranged from 0.60 to 0.98 across all test conditions and were not significantly different for inter-examiner (0.86), intra-examiner (0.87), and stride-to-stride reliability (0.86). The highest repeatability for the effect of location, direction and walking speed were for the shank segment (0.94), the vertical direction (0.91) and the fast walking speed (0.91), respectively. Overall, these results indicate that a high degree of waveform repeatability was obtained using a new gait system under test-retest conditions involving single and dual examiners. Furthermore, differences in acceleration waveform repeatability associated with the reapplication of accelerometers were small in relation to normal motor variability.

Surface-EMG analysis for the quantification of thigh muscle dynamic co-contractions during normal gait.

PubMed

Strazza, Annachiara; Mengarelli, Alessandro; Fioretti, Sandro; Burattini, Laura; Agostini, Valentina; Knaflitz, Marco; Di Nardo, Francesco

2017-01-01

The research purpose was to quantify the co-contraction patterns of quadriceps femoris (QF) vs. hamstring muscles during free walking, in terms of onset-offset muscular activation, excitation intensity, and occurrence frequency. Statistical gait analysis was performed on surface-EMG signals from vastus lateralis (VL), rectus femoris (RF), and medial hamstrings (MH), in 16315 strides walked by 30 healthy young adults. Results showed full superimpositions of MH with both VL and RF activity from terminal swing, 80 to 100% of gait cycle (GC), to the successive loading response (≈0-15% of GC), in around 90% of the considered strides. A further superimposition was detected during the push-off phase both between VL and MH activation intervals (38.6±12.8% to 44.1±9.6% of GC) in 21.9±13.6% of strides, and between RF and MH activation intervals (45.9±5.3% to 50.7±9.7 of GC) in 32.7±15.1% of strides. These findings led to identify three different co-contractions among QF and hamstring muscles during able-bodied walking: in early stance (in ≈90% of strides), in push-off (in 25-30% of strides) and in terminal swing (in ≈90% of strides). The co-contraction in terminal swing is the one with the highest levels of muscle excitation intensity. To our knowledge, this analysis represents the first attempt for quantification of QF/hamstring muscles co-contraction in young healthy subjects during normal gait, able to include the physiological variability of the phenomenon. Copyright © 2016 Elsevier B.V. All rights reserved.

Gait in adolescent idiopathic scoliosis: kinematics and electromyographic analysis

PubMed Central

Banse, X.; Mousny, M.; Detrembleur, C.

2009-01-01

Adolescent idiopathic scoliosis (AIS) is a progressive growth disease that affects spinal anatomy, mobility, and left-right trunk symmetry. Consequently, AIS can modify human locomotion. Very few studies have investigated a simple activity like walking in a cohort of well-defined untreated patients with scoliosis. The first goal of this study is to evaluate the effects of scoliosis and scoliosis severity on kinematic and electromyographic (EMG) gait variables compared to an able-bodied population. The second goal is to look for any asymmetry in these parameters during walking. Thirteen healthy girls and 41 females with untreated AIS, with left thoracolumbar or lumbar primary structural curves were assessed. AIS patients were divided into three clinical subgroups (group 1 < 20°, group 2 between 20 and 40°, and group 3 > 40°). Gait analysis included synchronous bilateral kinematic and EMG measurements. The subjects walked on a treadmill at 4 km/h (comfortable speed). The tridimensional (3D) shoulder, pelvis, and lower limb motions were measured using 22 reflective markers tracked by four infrared cameras. The EMG timing activity was measured using bipolar surface electrodes on quadratus lumborum, erector spinae, gluteus medius, rectus femoris, semitendinosus, tibialis anterior, and gastrocnemius muscles. Statistical comparisons (ANOVA) were performed across groups and sides for kinematic and EMG parameters. The step length was reduced in AIS compared to normal subjects (7% less). Frontal shoulder, pelvis, and hip motion and transversal hip motion were reduced in scoliosis patients (respectively, 21, 27, 28, and 22% less). The EMG recording during walking showed that the quadratus lumborum, erector spinae, gluteus medius, and semitendinosus muscles contracted during a longer part of the stride in scoliotic patients (46% of the stride) compared with normal subjects (35% of the stride). There was no significant difference between scoliosis groups 1, 2, and 3 for any of the kinematic and EMG parameters, meaning that severe scoliosis was not associated with increased differences in gait parameters compared to mild scoliosis. Scoliosis was not associated with any kinematic or EMG left–right asymmetry. In conclusion, scoliosis patients showed significant but slight modifications in gait, even in cases of mild scoliosis. With the naked eye, one could not see any difference from controls, but with powerful gait analysis technology, the pelvic frontal motion (right–left tilting) was reduced, as was the motion in the hips and shoulder. Surprisingly, no asymmetry was noted but the spine seemed dynamically stiffened by the longer contraction time of major spinal and pelvic muscles. Further studies are needed to evaluate the origin and consequences of these observations. PMID:19224255

Tiger beetles pursue prey using a proportional control law with a delay of one half-stride.

PubMed

Haselsteiner, Andreas F; Gilbert, Cole; Wang, Z Jane

2014-06-06

Tiger beetles are fast diurnal predators capable of chasing prey under closed-loop visual guidance. We investigated this control system using statistical analyses of high-speed digital recordings of beetles chasing a moving prey dummy in a laboratory arena. Correlation analyses reveal that the beetle uses a proportional control law in which the angular position of the prey relative to the beetle's body axis drives the beetle's angular velocity with a delay of about 28 ms. The proportionality coefficient or system gain, 12 s(-1), is just below critical damping. Pursuit simulations using the derived control law predict angular orientation during pursuits with a residual error of about 7°. This is of the same order of magnitude as the oscillation imposed by the beetle's alternating tripod gait, which was not factored into the control law. The system delay of 28 ms equals a half-stride period, i.e. the time between the touch down of alternating tripods. Based on these results, we propose a physical interpretation of the observed control law: to turn towards its prey, the beetle on average exerts a sideways force proportional to the angular position of the prey measured a half-stride earlier.

Ambiguity domain-based identification of altered gait pattern in ALS disorder

NASA Astrophysics Data System (ADS)

Sugavaneswaran, L.; Umapathy, K.; Krishnan, S.

2012-08-01

The onset of a neurological disorder, such as amyotrophic lateral sclerosis (ALS), is so subtle that the symptoms are often overlooked, thereby ruling out the option of early detection of the abnormality. In the case of ALS, over 75% of the affected individuals often experience awkwardness when using their limbs, which alters their gait, i.e. stride and swing intervals. The aim of this work is to suitably represent the non-stationary characteristics of gait (fluctuations in stride and swing intervals) in order to facilitate discrimination between normal and ALS subjects. We define a simple-yet-representative feature vector space by exploiting the ambiguity domain (AD) to achieve efficient classification between healthy and pathological gait stride interval. The stride-to-stride fluctuations and the swing intervals of 16 healthy control and 13 ALS-affected subjects were analyzed. Three features that are representative of the gait signal characteristics were extracted from the AD-space and are fed to linear discriminant analysis and neural network classifiers, respectively. Overall, maximum accuracies of 89.2% (LDA) and 100% (NN) were obtained in classifying the ALS gait.

Maximum swimming speeds of sailfish and three other large marine predatory fish species based on muscle contraction time and stride length: a myth revisited

PubMed Central

Svendsen, Morten B. S.; Domenici, Paolo; Marras, Stefano; Krause, Jens; Boswell, Kevin M.; Rodriguez-Pinto, Ivan; Wilson, Alexander D. M.; Kurvers, Ralf H. J. M.; Viblanc, Paul E.; Finger, Jean S.; Steffensen, John F.

2016-01-01

ABSTRACT Billfishes are considered to be among the fastest swimmers in the oceans. Previous studies have estimated maximum speed of sailfish and black marlin at around 35 m s−1 but theoretical work on cavitation predicts that such extreme speed is unlikely. Here we investigated maximum speed of sailfish, and three other large marine pelagic predatory fish species, by measuring the twitch contraction time of anaerobic swimming muscle. The highest estimated maximum swimming speeds were found in sailfish (8.3±1.4 m s−1), followed by barracuda (6.2±1.0 m s−1), little tunny (5.6±0.2 m s−1) and dorado (4.0±0.9 m s−1); although size-corrected performance was highest in little tunny and lowest in sailfish. Contrary to previously reported estimates, our results suggest that sailfish are incapable of exceeding swimming speeds of 10-15 m s−1, which corresponds to the speed at which cavitation is predicted to occur, with destructive consequences for fin tissues. PMID:27543056

Gait parameter control timing with dynamic manual contact or visual cues.

PubMed

Rabin, Ely; Shi, Peter; Werner, William

2016-06-01

We investigated the timing of gait parameter changes (stride length, peak toe velocity, and double-, single-support, and complete step duration) to control gait speed. Eleven healthy participants adjusted their gait speed on a treadmill to maintain a constant distance between them and a fore-aft oscillating cue (a place on a conveyor belt surface). The experimental design balanced conditions of cue modality (vision: eyes-open; manual contact: eyes-closed while touching the cue); treadmill speed (0.2, 0.4, 0.85, and 1.3 m/s); and cue motion (none, ±10 cm at 0.09, 0.11, and 0.18 Hz). Correlation analyses revealed a number of temporal relationships between gait parameters and cue speed. The results suggest that neural control ranged from feedforward to feedback. Specifically, step length preceded cue velocity during double-support duration suggesting anticipatory control. Peak toe velocity nearly coincided with its most-correlated cue velocity during single-support duration. The toe-off concluding step and double-support durations followed their most-correlated cue velocity, suggesting feedback control. Cue-tracking accuracy and cue velocity correlations with timing parameters were higher with the manual contact cue than visual cue. The cue/gait timing relationships generalized across cue modalities, albeit with greater delays of step-cycle events relative to manual contact cue velocity. We conclude that individual kinematic parameters of gait are controlled to achieve a desired velocity at different specific times during the gait cycle. The overall timing pattern of instantaneous cue velocities associated with different gait parameters is conserved across cues that afford different performance accuracies. This timing pattern may be temporally shifted to optimize control. Different cue/gait parameter latencies in our nonadaptation paradigm provide general-case evidence of the independent control of gait parameters previously demonstrated in gait adaptation paradigms. Copyright © 2016 the American Physiological Society.

Evaluation of an activity monitor for the objective measurement of free-living physical activity in children with cerebral palsy.

PubMed

Tang, Kit Tzu; Richardson, Alison M; Maxwell, Douglas; Spence, William D; Stansfield, Benedict W

2013-12-01

To explore the use of an activity monitor (AM) to objectively characterize free-living physical activity (F-LPA) in children with mobility impairment resulting from cerebral palsy (CP). First, a validation study compared outcomes from the AM with video evidence. Second, multiday F-LPA was characterized. Relationships between laboratory measures and F-LPA were explored. The evaluation study was conducted in a laboratory environment. F-LPA monitoring was conducted in the participants' free-living environment. Convenience sample of ambulatory children (N=15; 11 boys, 4 girls) aged 5 to 17 years with CP undergoing gait analysis. Not applicable. Accuracy of the AM for sitting/lying time, upright time, stepping time, and strides taken. Daily volumes of F-LPA of children with CP. AM outcomes in comparison with video-based analysis were (mean ± SD) 97.4%±2.7%, 101.1%±1.5%, 99.5%±6.6%, 105.6%±15.8%, and 103.8%±10.1% for sitting/lying time, upright time, standing time, stepping time, and stride count, respectively. Participants' daily F-LPA demonstrated considerable variation: mean standing time ± SD, 2.33±.96h/d; mean stepping time ± SD, 1.68±.86h/d; mean steps per day ± SD, 8477±4528; and mean sit-to-stand transitions per day ± SD, 76±49. Laboratory-measured cadence and mobility level were related to F-LPA, but not directly. The AM demonstrated excellent ability to determine sitting/lying and upright times in children with CP. Stepping time and stride count had lower levels of agreement with video-based analysis but were comparable to findings in previous studies. Crouch gait and toe walking had an adverse effect on outcomes. The F-LPA data provided additional information on children's performance not related to laboratory measures, demonstrating the added value of using this objective measurement technique. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Effects of a structured midsole on spatio-temporal variables and running economy in overground running.

PubMed

Wunsch, Tobias; Kröll, Josef; Stöggl, Thomas; Schwameder, Hermann

2017-04-01

Research to enhance running performance has led to the design of a leaf spring-structured midsole shoe (LEAF). In treadmill running, it has been shown that LEAF led to an increased running economy and increased stride length (SL) through a horizontal foot shift during stance compared to a standard foam shoe (FOAM). The purpose of this study was to analyse whether (a) these findings can also be observed in overground running and (b) relations exist between spatio-temporal variables and running economy. Ten male long-distance heel-strike runners ran at their individual 2 mmol/l blood lactate speed with LEAF and FOAM in randomized order. Kinematic data were recorded with an inertial measurement unit synchronized with 2D video. Oxygen consumption was measured using an automated metabolic gas analysis system. Blood lactate was collected after each run. The strike pattern was unaffected by LEAF. SL was increased by 0.9 ± 1.1 cm (95% CI 0.2 to 1.5; p = .040; d z  = 0.76), stride rate (SR) was reduced by -0.4 ± 0.3 strides/min (95% CI -0.6 to -0.1; p = .029; d z  = 0.82) and oxygen consumption tended to be reduced by 1% (-0.4 ± 0.6 ml/min/kg; 95% CI -0.8 to 0.0; p = .082; d z  = 0.62) when running with LEAF compared to FOAM. Changes in oxygen consumption in LEAF were correlated with SL (r = 0.71; p = .022) and SR (r = -0.68; p = .031). It can be concluded that LEAF has the potential to cause small changes in spatio-temporal variables during running. Runners increasing SL and decreasing SR in response to LEAF can achieve small improvements in running economy, which is beneficial in terms of performance.

Fear of Falling Is Prevalent in Older Adults with Diabetes Mellitus But Is Unrelated to Level of Neuropathy

PubMed Central

Kelly, Carolyn; Fleischer, Adam; Yalla, Sai; Grewal, Gurtej S.; Albright, Rachel; Berns, Dana; Crews, Ryan; Najafi, Bijan

2016-01-01

Background Patients with diabetic peripheral neuropathy (DPN) demonstrate gait alterations compared with their nonneuropathic counterparts, which may place them at increased risk for falling. However, it is uncertain whether patients with DPN also have a greater fear of falling. Methods A voluntary group of older adults with diabetes was asked to complete a validated fear of falling questionnaire (Falls Efficacy Scale International [FES-I]) and instructed to walk 20 m in their habitual shoes at their habitual speed. Spatiotemporal parameters of gait (eg, stride velocity and gait speed variability) were collected using a validated body-worn sensor technology. Balance during walking was also assessed using sacral motion in the mediolateral and anteroposterior directions. The level of DPN was quantified using vibration perception threshold from the great toe. Results Thirty-four diabetic patients (mean ± SD: age, 67.6 ± 9.2 years; body mass index, 30.9 ± 5.7; hemoglobin A1c, 7.9% ± 2.3%) with varying levels of neuropathy (mean ± SD vibration perception threshold, 34.6 ± 22.9 V) were recruited. Most participants (28 of 34, 82%) demonstrated moderate to high concern about falling based on their FES-I score. Age (r = 0.6), hemoglobin A1c level (r = 0.39), number of steps required to reach steady-state walking (ie, gait initiation) (r = 0.4), and duration of double support (r = 0.44) were each positively correlated with neuropathy severity (P < .05). Participants with a greater fear of falling also walked with slower stride velocities and shorter stride lengths (r = −0.3 for both, P < .05). However, no correlation was observed between level of DPN and the participant’s actual concern about falling. Conclusions Fear of falling is prevalent in older adults with diabetes mellitus but is unrelated to level of neuropathy. PMID:24297984

Interaction between thorax, lumbar, and pelvis movements in the transverse plane during gait at three velocities.

PubMed

Yang, Ya-Ting; Yoshida, Yasuyuki; Hortobágyi, Tibor; Suzuki, Shuji

2013-06-01

We determined the angular range of motion and the relative timing of displacement in the thorax, lumbar spine, and pelvis in the transverse plane during treadmill walking at three velocities. Nine healthy young females walked on a treadmill for three minutes at 0.40, 0.93, and 1.47 m/s. The position of seven reflective markers and three rigs placed on the thorax, lumbar spine, and pelvis were recorded at 200 Hz by an eight-camera motion capture system. As gait velocity increased, stride length increased, cycle time decreased, and angular displacement in the thorax and L1 decreased but increased at the pelvis and L5 (all P < .05). The time of maxi- mal angular rotation occurred in the following sequence: pelvis, L5, L3, L1, and thorax (P < .001). The thorax and L1 and L3 were in-phase for shorter duration as gait velocity increased, and this reduction was especially large, approx. 32% (P < .05), between thorax and pelvis. As gait velocity increased, the pelvis rotated earlier, causing the shortening of in-phase duration between thorax and pelvis. These data suggest that, as gait velocity increases, pelvis rotation dictates trunk rotation in the transverse plane during gait in healthy young females.

Kinematic Analysis of Gait Following Intra-articular Corticosteroid Injection into the Knee Joint with an Acute Exacerbation of Arthritis

PubMed Central

Mehta, Saurabh; Szturm, Tony; El-Gabalawy, Hani S.

2011-01-01

ABSTRACT Purpose: The objective of this study was to examine the effects of intra-articular corticosteroid injection (ICI) on ipsilateral knee flexion/extension, ankle dorsiflexion/plantarflexion (DF/PF), and hip abduction/adduction (abd/add) during stance phase in people with an acute exacerbation of rheumatoid arthritis (RA) of the knee joint. The study also assessed the effects of ICI on spatiotemporal parameters of gait and functional status in this group. Methods: Nine people with an exacerbation of RA of the knee were recruited. Kinematic and spatiotemporal gait parameters were obtained for each participant. Knee-related functional status was assessed using the Knee injury and Osteoarthritis Outcome Score (KOOS). Spatiotemporal gait parameters and joint angles (knee flexion, ankle DF/PF, hip abd/add) of the affected side were compared pre- and post-ICI. Results: Data for eight people were available for analysis. Median values for knee flexion and ankle PF increased significantly following ICI. Gait parameters of cadence, velocity, bilateral stride length, bilateral step length, step width, double-support percentage, and step time on the affected side also showed improvement. Pain and knee-related functional status as measured by the KOOS showed improvement. Conclusions: This study demonstrated a beneficial short-term effect of ICI on knee-joint movements, gait parameters, and knee-related functional status in people with acute exacerbation of RA of the knee. PMID:22942516

Striding through Time

ERIC Educational Resources Information Center

Clary, Renee; Wandersee, James

2014-01-01

The "Next Generation Science Standards" (NGSS) focus attention on integrating engineering and math in science instruction. The dinosaur trackway project described in this article shows that it is possible to assign engineering applications to students in disciplines other than physics and to integrate math and engineering applications in…

Optic flow odometry operates independently of stride integration in carried ants.

PubMed

Pfeffer, Sarah E; Wittlinger, Matthias

2016-09-09

Cataglyphis desert ants are impressive navigators. When the foragers roam the desert, they employ path integration. For these ants, distance estimation is one key challenge. Distance information was thought to be provided by optic flow (OF)-that is, image motion experienced during travel-but this idea was abandoned when stride integration was discovered as an odometer mechanism in ants. We show that ants transported by nest mates are capable of measuring travel distance exclusively by the use of OF cues. Furthermore, we demonstrate that the information gained from the optic flowmeter cannot be transferred to the stride integrator. Our results suggest a dual information channel that allows the ants to measure distances by strides and OF cues, although both systems operate independently and in a redundant manner. Copyright © 2016, American Association for the Advancement of Science.

Persistent fluctuations in stride intervals under fractal auditory stimulation.

PubMed

Marmelat, Vivien; Torre, Kjerstin; Beek, Peter J; Daffertshofer, Andreas

2014-01-01

Stride sequences of healthy gait are characterized by persistent long-range correlations, which become anti-persistent in the presence of an isochronous metronome. The latter phenomenon is of particular interest because auditory cueing is generally considered to reduce stride variability and may hence be beneficial for stabilizing gait. Complex systems tend to match their correlation structure when synchronizing. In gait training, can one capitalize on this tendency by using a fractal metronome rather than an isochronous one? We examined whether auditory cues with fractal variations in inter-beat intervals yield similar fractal inter-stride interval variability as isochronous auditory cueing in two complementary experiments. In Experiment 1, participants walked on a treadmill while being paced by either an isochronous or a fractal metronome with different variation strengths between beats in order to test whether participants managed to synchronize with a fractal metronome and to determine the necessary amount of variability for participants to switch from anti-persistent to persistent inter-stride intervals. Participants did synchronize with the metronome despite its fractal randomness. The corresponding coefficient of variation of inter-beat intervals was fixed in Experiment 2, in which participants walked on a treadmill while being paced by non-isochronous metronomes with different scaling exponents. As expected, inter-stride intervals showed persistent correlations similar to self-paced walking only when cueing contained persistent correlations. Our results open up a new window to optimize rhythmic auditory cueing for gait stabilization by integrating fractal fluctuations in the inter-beat intervals.

Persistent Fluctuations in Stride Intervals under Fractal Auditory Stimulation

PubMed Central

Marmelat, Vivien; Torre, Kjerstin; Beek, Peter J.; Daffertshofer, Andreas

2014-01-01

Stride sequences of healthy gait are characterized by persistent long-range correlations, which become anti-persistent in the presence of an isochronous metronome. The latter phenomenon is of particular interest because auditory cueing is generally considered to reduce stride variability and may hence be beneficial for stabilizing gait. Complex systems tend to match their correlation structure when synchronizing. In gait training, can one capitalize on this tendency by using a fractal metronome rather than an isochronous one? We examined whether auditory cues with fractal variations in inter-beat intervals yield similar fractal inter-stride interval variability as isochronous auditory cueing in two complementary experiments. In Experiment 1, participants walked on a treadmill while being paced by either an isochronous or a fractal metronome with different variation strengths between beats in order to test whether participants managed to synchronize with a fractal metronome and to determine the necessary amount of variability for participants to switch from anti-persistent to persistent inter-stride intervals. Participants did synchronize with the metronome despite its fractal randomness. The corresponding coefficient of variation of inter-beat intervals was fixed in Experiment 2, in which participants walked on a treadmill while being paced by non-isochronous metronomes with different scaling exponents. As expected, inter-stride intervals showed persistent correlations similar to self-paced walking only when cueing contained persistent correlations. Our results open up a new window to optimize rhythmic auditory cueing for gait stabilization by integrating fractal fluctuations in the inter-beat intervals. PMID:24651455

Continuous positive airway pressure improves gait control in severe obstructive sleep apnoea: A prospective study

PubMed Central

Wuyam, Bernard; Pépin, Jean-Louis; Marillier, Mathieu; Tamisier, Renaud; Pérennou, Dominic; Verges, Samuel

2018-01-01

Study aim Severe obstructive sleep apnoea (OSA) can lead to neurocognitive alterations, including gait impairments. The beneficial effects of continuous positive airway pressure (CPAP) on improving excessive daytime sleepiness and daily functioning have been documented. However, a demonstration of CPAP treatment efficacy on gait control is still lacking. This study aims to test the hypothesis that CPAP improves gait control in severe OSA patients. Material and methods In this prospective controlled study, twelve severe OSA patients (age = 57.2±8.9 years, body mass index = 27.4±3.1 kg·m-2, apnoea-hypopnoea index = 46.3±11.7 events·h-1) and 10 healthy matched subjects were included. Overground gait parameters were recorded at spontaneous speed and stride time variability, a clinical marker of gait control, was calculated. To assess the role of executive functions in gait and postural control, a dual-task paradigm was applied using a Stroop test as secondary cognitive task. All assessments were performed before and after 8 weeks of CPAP treatment. Results Before CPAP treatment, OSA patients had significantly larger stride time variability (3.1±1.1% vs 2.1±0.5%) and lower cognitive performances under dual task compared to controls. After CPAP treatment, stride time variability was significantly improved and no longer different compared to controls. Cognitive performance under dual task also improved after CPAP treatment. Conclusion Eight weeks of CPAP treatment improves gait control of severe OSA patients, suggesting morphological and functional cerebral improvements. Our data provide a rationale for further mechanistic studies and the use of gait as a biomarker of OSA brain consequences. PMID:29474363

Together We STRIDE: A quasi-experimental trial testing the effectiveness of a multi-level obesity intervention for Hispanic children in rural communities.

PubMed

Ko, Linda K; Rillamas-Sun, Eileen; Bishop, Sonia; Cisneros, Oralia; Holte, Sarah; Thompson, Beti

2018-04-01

Hispanic children are disproportionally overweight and obese compared to their non-Hispanic white counterparts in the US. Community-wide, multi-level interventions have been successful to promote healthier nutrition, increased physical activity (PA), and weight loss. Using community-based participatory approach (CBPR) that engages community members in rural Hispanic communities is a promising way to promote behavior change, and ultimately weight loss among Hispanic children. Led by a community-academic partnership, the Together We STRIDE (Strategizing Together Relevant Interventions for Diet and Exercise) aims to test the effectiveness of a community-wide, multi-level intervention to promote healthier diets, increased PA, and weight loss among Hispanic children. The Together We STRIDE is a parallel quasi-experimental trial with a goal of recruiting 900 children aged 8-12 years nested within two communities (one intervention and one comparison). Children will be recruited from their respective elementary schools. Components of the 2-year multi-level intervention include comic books (individual-level), multi-generational nutrition and PA classes (family-level), teacher-led PA breaks and media literacy education (school-level), family nights, a farmer's market and a community PA event (known as ciclovia) at the community-level. Children from the comparison community will receive two newsletters. Height and weight measures will be collected from children in both communities at three time points (baseline, 6-months, and 18-months). The Together We STRIDE study aims to promote healthier diet and increased PA to produce healthy weight among Hispanic children. The use of CBPR approach and the engagement of the community will springboard strategies for intervention' sustainability. Clinical Trials Registration Number: NCT02982759 Retrospectively registered. Copyright © 2018 Elsevier Inc. All rights reserved.

Long-Range Correlations in Stride Intervals May Emerge from Non-Chaotic Walking Dynamics

PubMed Central

Ahn, Jooeun; Hogan, Neville

2013-01-01

Stride intervals of normal human walking exhibit long-range temporal correlations. Similar to the fractal-like behaviors observed in brain and heart activity, long-range correlations in walking have commonly been interpreted to result from chaotic dynamics and be a signature of health. Several mathematical models have reproduced this behavior by assuming a dominant role of neural central pattern generators (CPGs) and/or nonlinear biomechanics to evoke chaos. In this study, we show that a simple walking model without a CPG or biomechanics capable of chaos can reproduce long-range correlations. Stride intervals of the model revealed long-range correlations observed in human walking when the model had moderate orbital stability, which enabled the current stride to affect a future stride even after many steps. This provides a clear counterexample to the common hypothesis that a CPG and/or chaotic dynamics is required to explain the long-range correlations in healthy human walking. Instead, our results suggest that the long-range correlation may result from a combination of noise that is ubiquitous in biological systems and orbital stability that is essential in general rhythmic movements. PMID:24086274

Physiological and Biomechanical Responses of Highly Trained Distance Runners to Lower-Body Positive Pressure Treadmill Running.

PubMed

Barnes, Kyle R; Janecke, Jessica N

2017-11-21

As a way to train at faster running speeds, add training volume, prevent injury, or rehabilitate after an injury, lower-body positive pressure treadmills (LBPPT) have become increasingly commonplace among athletes. However, there are conflicting evidence and a paucity of data describing the physiological and biomechanical responses to LBPPT running in highly trained or elite caliber runners at the running speeds they habitually train at, which are considerably faster than those of recreational runners. Furthermore, data is lacking regarding female runners' responses to LBPPT running. Therefore, this study was designed to evaluate the physiological and biomechanical responses to LBPPT running in highly trained male and female distance runners. Fifteen highly trained distance runners (seven male; eight female) completed a single running test composed of 4 × 9-min interval series at fixed percentages of body weight ranging from 0 to 30% body weight support (BWS) in 10% increments on LBPPT. The first interval was always conducted at 0% BWS; thereafter, intervals at 10, 20, and 30% BWS were conducted in random order. Each interval consisted of three stages of 3 min each, at velocities of 14.5, 16.1, and 17.7 km·h -1 for men and 12.9, 14.5, and 16.1 km·h -1 for women. Expired gases, ventilation, breathing frequency, heart rate (HR), rating of perceived exertion (RPE), and stride characteristics were measured during each running speed and BWS. Male and female runners had similar physiological and biomechanical responses to running on LBPPT. Increasing BWS increased stride length (p < 0.02) and flight duration (p < 0.01) and decreased stride rate (p < 0.01) and contact time (p < 0.01) in small-large magnitudes. There was a large attenuation of oxygen consumption (VO 2 ) relative to BWS (p < 0.001), while there were trivial-moderate reductions in respiratory exchange ratio, minute ventilation, and respiratory frequency (p > 0.05), and small-large effects on HR and RPE (p < 0.01). There were trivial-small differences in V E , respiratory frequency, HR, and RPE for a given VO 2 across various BWS (p > 0.05). The results indicate the male and female distance runners have similar physiological and biomechanical responses to LBPPT running. Overall, the biomechanical changes during LBPPT running all contributed to less metabolic cost and corresponding physiological changes.

A comparative study of the effects of trunk exercise program in aquatic and land-based therapy on gait in hemiplegic stroke patients.

PubMed

Park, Byoung-Sun; Noh, Ji-Woong; Kim, Mee-Young; Lee, Lim-Kyu; Yang, Seung-Min; Lee, Won-Deok; Shin, Yong-Sub; Kim, Ju-Hyun; Lee, Jeong-Uk; Kwak, Taek-Yong; Lee, Tae-Hyun; Park, Jaehong; Kim, Junghwan

2016-06-01

[Purpose] The purpose of this study was to compare the effects of aquatic and land-based trunk exercise program on gait in stroke patients. [Subjects and Methods] The subjects were 28 hemiplegic stroke patients (20 males, 8 females). The subjects performed a trunk exercise program for a total of four weeks. [Results] Walking speed and cycle, stance phase and stride length of the affected side, and the symmetry index of the stance phase significantly improved after the aquatic and land-based trunk exercise program. [Conclusion] These results suggest that the aquatic and land-based trunk exercise program may help improve gait performance ability after stroke.

The effect of waist twisting on walking speed of an amphibious salamander like robot

NASA Astrophysics Data System (ADS)

Yin, Xin-Yan; Jia, Li-Chao; Wang, Chen; Xie, Guang-Ming

2016-06-01

Amphibious salamanders often swing their waist to coordinate quadruped walking in order to improve their crawling speed. A robot with a swing waist joint, like an amphibious salamander, is used to mimic this locomotion. A control method is designed to allow the robot to maintain the rotational speed of its legs continuous and avoid impact between its legs and the ground. An analytical expression is established between the amplitude of the waist joint and the step length. Further, an optimization amplitude is obtained corresponding to the maximum stride. The simulation results based on automatic dynamic analysis of mechanical systems (ADAMS) and physical experiments verify the rationality and validity of this expression.

BIOSENSOR TECHNOLOGY EVALUATIONS FOR REAL-TIME/SOURCE WATER PROTECTION

EPA Science Inventory

Recent advances in electronics and computer technology have made great strides in the field of remote sensing and biomonitoring. The quality of drinking water sources has come under closer scrutiny in recent years. Issues ranging from ecological to public health and national se...

Research Review

ERIC Educational Resources Information Center

Serig, Dan; Hinojosa, Tina

2010-01-01

The field of community art within higher education has made tremendous strides in the past two decades. The origins of community visual arts programming are ambiguous and traceable to multiple time periods and cultural contexts. However, in contemporary practices, higher education institutions are slowly adopting a greater priority for community…

Effects of load carriage and footwear on lower extremity kinetics and kinematics during overground walking.

PubMed

Dames, Kevin D; Smith, Jeremy D

2016-10-01

Kinetic and kinematic responses during walking vary by footwear condition. Load carriage also influences gait patterns, but it is unclear how an external load influences barefoot walking. Twelve healthy adults (5 women, 7 men) with no known gait abnormalities participated in this study (age=23±3years, height=1.73±0.11m, and mass=70.90±12.67kg). Ground reaction forces and 3D motion were simultaneously collected during overground walking at 1.5ms -1 in four conditions: Barefoot Unloaded, Shod Unloaded, Barefoot Loaded, and Shod Loaded. Barefoot walking reduced knee and hip joint ranges of motion, as well as stride length, stance time, swing time, and double support time. Load carriage increased stance and double support times. The 15% body weight load increased GRFs ∼15%. Walking barefoot reduced peak anteroposterior GRFs but not peak vertical GRFs. Load carriage increased hip, knee, and ankle joint moments and powers, while walking barefoot increased knee and hip moments and powers. Thus, spatiotemporal and kinematic adjustments to walking barefoot decrease GRFs but increase knee and hip kinetic measures during overground walking. The ankle seems to be less affected by these footwear conditions. Regardless of footwear, loading requires larger GRFs, joint loads, and joint powers. Copyright © 2016 Elsevier B.V. All rights reserved.

A quantitative analysis of gait patterns in vestibular neuritis patients using gyroscope sensor and a continuous walking protocol

PubMed Central

2014-01-01

Background Locomotion involves an integration of vision, proprioception, and vestibular information. The parieto-insular vestibular cortex is known to affect the supra-spinal rhythm generators, and the vestibular system regulates anti-gravity muscle tone of the lower leg in the same side to maintain an upright posture through the extra-pyramidal track. To demonstrate the relationship between locomotion and vestibular function, we evaluated the differences in gait patterns between vestibular neuritis (VN) patients and normal subjects using a gyroscope sensor and long-way walking protocol. Methods Gyroscope sensors were attached to both shanks of healthy controls (n=10) and age-matched VN patients (n = 10). We then asked the participants to walk 88.8 m along a corridor. Through the summation of gait cycle data, we measured gait frequency (Hz), normalized angular velocity (NAV) of each axis for legs, maximum and minimum NAV, up-slope and down-slope of NAV in swing phase, stride-swing-stance time (s), and stance to stride ratio (%). Results The most dominant walking frequency in the VN group was not different compared to normal control. The NAVs of z-axis (pitch motion) were significantly larger than the others (x-, y-axis) and the values in VN patients tended to decrease in both legs and the difference of NAV between both group was significant in the ipsi-lesion side in the VN group only (p=0.03). Additionally, the gait velocity of these individuals was decreased relatively to controls (1.11 ± 0.120 and 0.84 ± 0.061 m/s in control and VN group respectively, p<0.01), which seems to be related to the significantly increased stance and stride time of the ipsi-lesion side. Moreover, in the VN group, the maximum NAV of the lesion side was less, and the minimum one was higher than control group. Furthermore, the down-slope and up-slope of NAV decreased on the impaired side. Conclusion The walking pattern of VN patients was highly phase-dependent, and NAV of pitch motion was significantly decreased in the ipsi-lesion side. The change of gait rhythm, stance and stride time, and maximum/minimum NAV of the ipsi-lesion side were characteristics of individuals with VN. PMID:24725764

A quantitative analysis of gait patterns in vestibular neuritis patients using gyroscope sensor and a continuous walking protocol.

PubMed

Kim, Soo Chan; Kim, Joo Yeon; Lee, Hwan Nyeong; Lee, Hwan Ho; Kwon, Jae Hwan; Kim, Nam Beom; Kim, Mi Joo; Hwang, Jong Hyun; Han, Gyu Cheol

2014-04-11

Locomotion involves an integration of vision, proprioception, and vestibular information. The parieto-insular vestibular cortex is known to affect the supra-spinal rhythm generators, and the vestibular system regulates anti-gravity muscle tone of the lower leg in the same side to maintain an upright posture through the extra-pyramidal track. To demonstrate the relationship between locomotion and vestibular function, we evaluated the differences in gait patterns between vestibular neuritis (VN) patients and normal subjects using a gyroscope sensor and long-way walking protocol. Gyroscope sensors were attached to both shanks of healthy controls (n=10) and age-matched VN patients (n = 10). We then asked the participants to walk 88.8 m along a corridor. Through the summation of gait cycle data, we measured gait frequency (Hz), normalized angular velocity (NAV) of each axis for legs, maximum and minimum NAV, up-slope and down-slope of NAV in swing phase, stride-swing-stance time (s), and stance to stride ratio (%). The most dominant walking frequency in the VN group was not different compared to normal control. The NAVs of z-axis (pitch motion) were significantly larger than the others (x-, y-axis) and the values in VN patients tended to decrease in both legs and the difference of NAV between both group was significant in the ipsi-lesion side in the VN group only (p=0.03). Additionally, the gait velocity of these individuals was decreased relatively to controls (1.11 ± 0.120 and 0.84 ± 0.061 m/s in control and VN group respectively, p<0.01), which seems to be related to the significantly increased stance and stride time of the ipsi-lesion side. Moreover, in the VN group, the maximum NAV of the lesion side was less, and the minimum one was higher than control group. Furthermore, the down-slope and up-slope of NAV decreased on the impaired side. The walking pattern of VN patients was highly phase-dependent, and NAV of pitch motion was significantly decreased in the ipsi-lesion side. The change of gait rhythm, stance and stride time, and maximum/minimum NAV of the ipsi-lesion side were characteristics of individuals with VN.

EPA Making Strides in Cleaning Up the Nation’s Most Contaminated Sites

EPA Pesticide Factsheets

Due to the hard work of staff to implement Administrator Pruitt's initiatives to make strides in cleaning up the nation's most contaminated toxic land sites, the USEPA is announcing significant improvement in 2017...

[Influence of Restricting the Ankle Joint Complex Motions on Gait Stability of Human Body].

PubMed

Li, Yang; Zhang, Junxia; Su, Hailong; Wang, Xinting; Zhang, Yan

2016-10-01

The purpose of this study is to determine how restricting inversion-eversion and pronation-supination motions of the ankle joint complex influences the stability of human gait.The experiment was carried out on a slippery level ground walkway.Spatiotemporal gait parameter,kinematics and kinetics data as well as utilized coefficient of friction(UCOF)were compared between two conditions,i.e.with restriction of the ankle joint complex inversion-eversion and pronation-supination motions(FIXED)and without restriction(FREE).The results showed that FIXED could lead to a significant increase in velocity and stride length and an obvious decrease in double support time.Furthermore,FIXED might affect the motion angle range of knee joint and ankle joint in the sagittal plane.In FIXED condition,UCOF was significantly increased,which could lead to an increase of slip probability and a decrease of gait stability.Hence,in the design of a walker,bipedal robot or prosthetic,the structure design which is used to achieve the ankle joint complex inversion-eversion and pronation-supination motions should be implemented.

Restoration of gait by functional electrical stimulation in paraplegic patients: a modified programme of treatment.

PubMed

Malezic, M; Hesse, S

1995-03-01

Restoration of standing and of gait by functional electrical stimulation in clinically complete paraplegic patients was modified in the course of treatment and in the stimulation parameters. By substituting an initial cyclic muscle strengthening with an active stimulated standing, four patients with T3-11 lesions started walking with electrical stimulation in 10-17 days. They walked without ankle-foot orthoses. With a satisfactory stride length of 0.75-0.97 m, their gait velocity ranged from very slow to that of a leisurely healthy gait. Already established stimulation of the quadriceps muscles for standing and of the peroneal nerves for lower limb flexion during the swing phase of gait was applied. Diminished limb flexion after several weeks was restored by an increase of the stimulation frequency of the peroneal nerve from 20 to 60 Hz. EMG and kinesiological measurements displayed an improved direct response of the ankle as well as of the reflex mediated hip, knee and ankle flexion response. At the same time stimulation frequency was reduced to 16 Hz for the quadriceps muscles in order to reduce fatigue.

An assistive controller for a lower-limb exoskeleton for rehabilitation after stroke, and preliminary assessment thereof.

PubMed

Murray, Spencer A; Ha, Kevin H; Goldfarb, Michael

2014-01-01

This paper describes a novel controller, intended for use in a lower-limb exoskeleton, to aid gait rehabilitation in patients with hemiparesis after stroke. The controller makes use of gravity compensation, feedforward movement assistance, and reinforcement of isometric joint torques to achieve assistance without dictating the spatiotemporal nature of joint movement. The patient is allowed to self-select walking speed and is able to make trajectory adaptations to maintain balance without interference from the controller. The governing equations and the finite state machine which comprise the system are described herein. The control architecture was implemented in a lower-limb exoskeleton and a preliminary experimental assessment was conducted in which a patient with hemiparesis resulting from stroke walked with assistance from the exoskeleton. The patient exhibited improvements in fast gait speed, step length asymmetry, and stride length in each session, as measured before and after exoskeleton training, presumably as a result of using the exoskeleton.

Tiger beetles pursue prey using a proportional control law with a delay of one half-stride

PubMed Central

Haselsteiner, Andreas F.; Gilbert, Cole; Wang, Z. Jane

2014-01-01

Tiger beetles are fast diurnal predators capable of chasing prey under closed-loop visual guidance. We investigated this control system using statistical analyses of high-speed digital recordings of beetles chasing a moving prey dummy in a laboratory arena. Correlation analyses reveal that the beetle uses a proportional control law in which the angular position of the prey relative to the beetle's body axis drives the beetle's angular velocity with a delay of about 28 ms. The proportionality coefficient or system gain, 12 s−1, is just below critical damping. Pursuit simulations using the derived control law predict angular orientation during pursuits with a residual error of about 7°. This is of the same order of magnitude as the oscillation imposed by the beetle's alternating tripod gait, which was not factored into the control law. The system delay of 28 ms equals a half-stride period, i.e. the time between the touch down of alternating tripods. Based on these results, we propose a physical interpretation of the observed control law: to turn towards its prey, the beetle on average exerts a sideways force proportional to the angular position of the prey measured a half-stride earlier. PMID:24718454

Fetlock joint kinematics differ with age in Thoroughbred [was thoroughbred] racehorses.

PubMed

Butcher, Michael T; Ashley-Ross, M A

2002-05-01

Fetlock joint kinematics during galloping in 2-, 3-, 4-, and 5-year-old Thoroughbreds in race training were quantified to determine if differences due to age could account for the observation that 2-year old Thoroughbred racehorses incur a high number of injuries to the bones and soft tissues in the distal forelimbs during training and at the outset of racing. Twelve Thoroughbred racehorses were videotaped in the sagittal plane at 250 frames/s during their daily galloping workout on a 7/8 mile sand-surface training track. Four galloping strides were recorded for each horse and subsequently digitized to determine fetlock joint angles of the leading forelimb during the limb support period of a stride. Four kinematic variables were measured from each stride's angular profile: angle of fetlock joint dorsi-flexion at mid-stance, negative angular velocity, positive angular velocity and time from hoof impact to mid-stance phase of limb support. The 2-year old Thoroughbreds had significantly quicker rates of dorsi-flexion of their fetlock joints than 3- (p=0.01), 4- (p=0.01), and 5-year old (p<0.01) Thoroughbreds following impact of the leading forelimb during moderate galloping (avg. 14 m/s). Higher rates of dorsi-flexion in young Thoroughbreds may reflect immaturity (lack of stiffness) of the suspensory apparatus tissues.

Effect of a dual task on quantitative Timed Up and Go performance in community-dwelling older adults: A preliminary study.

PubMed

Smith, Erin; Walsh, Lorcan; Doyle, Julie; Greene, Barry; Blake, Catherine

2017-08-01

The Timed Up and Go test (TUG) is used as a measure of functional ability in older adults; however, the method of measurement does not allow us to determine which aspects of the test deficits occur in. The aim of the present study was to examine the ability of the quantitative TUG (QTUG) to measure performance during the TUG test under three different conditions - single task, motor task and cognitive dual task - and to compare performance between fallers and non-fallers in high-functioning community-dwelling older adults. A total of 37 community-dwelling older adults, 16 with a self-reported falls history in the previous year, were recruited. Participants underwent a falls risk assessment with a physiotherapist including the QTUG under three conditions (single task, motor task, cognitive dual-task). A total of 10 clinical parameters were chosen for analysis using mancova and a series of ancova, with age, sex and body mass index included as covariates. The mancova analysis showed a significant difference across the three task conditions (Wilk's Lambda F 20,186  = 3.37, P < 0.001. No overall significant difference between faller and non-faller groups (Wilk's Lambda F 10,96  = 1.469, P = 0.163) or significant interaction between task and faller status (Wilk's Lambda F 20,192  = 1.131, P = 0.321) was found. ancova results for each of the parameters showed overall differences between single, motor and cognitive tasks for all of the variables, except time in double support. When faller and non-faller differences were explored, cadence and stride velocity was greater, and stride time longer in those with a prior history of falls. In community-dwelling older adults, these preliminary results show that a cognitive dual-task significantly (P < 0.025) affects QTUG performance in almost all parameters, with a significant (P < 0.025) reduction in time-to-stand observed with a motor task. Although no statistical difference was found between fallers and non-fallers for many of the parameters, cadence, stride time and stride velocity were statistically different (P < 0.05). A larger sample size and more assessment points might lead to more definitive findings. These results highlight the need for further research to examine QTUG performance under dual-task conditions between fallers and non-fallers in this population, and to look at the ability of dual-task QTUG assessment to measure change longitudinally and the effectiveness of therapeutic interventions. Geriatr Gerontol Int 2017; 17: 1176-1182. © 2016 Japan Geriatrics Society.

Effects of perturbation-based slip training using a virtual reality environment on slip-induced falls.

PubMed

Parijat, Prakriti; Lockhart, Thurmon E; Liu, Jian

2015-04-01

The purpose of the current study was to design and evaluate the effectiveness of virtual reality training in improving recovery reactions and reducing fall frequency in older adults. Twenty-four older adults were recruited and randomly assigned to two groups (virtual reality training and control). Both groups underwent three sessions including baseline slip, training and transfer of training on slippery surface. Both groups experienced two slips, one during baseline and the other during the transfer of training trial. The training group underwent 12 simulated slips using a visual perturbation induced by tilting a virtual reality scene while walking on the treadmill and the control group performed normal walking during the training session. Kinematic and kinetic data were collected during all the sessions. Results demonstrated a reduced incidence of falls in the training group during the transfer of training trial as compared to the control group. The training group was able to transfer reactive control strategies learned during training to the second slip trial. The reactive adjustments included reduced slip distance. Additionally, gait parameters reflective of gait instability (stride length, step width, variability in stride velocity) reduced after walking in the VR environment for 15-20 min. The results indicated a beneficial effect of the virtual reality training in reducing slip severity and recovery kinematics in healthy older adults.

Effect of 3 Weeks Use of Compression Garments on Stride and Impact Shock during a Fatiguing Run.

PubMed

Lucas-Cuevas, A G; Priego-Quesada, J I; Aparicio, I; Giménez, J V; Llana-Belloch, S; Pérez-Soriano, P

2015-10-01

Excessive and prolonged exposure to impact acceleration during running is associated with increased injury rate. Acute use of compressive garments has been speculated to improve attenuation. However, it is unknown how longer interventions of compressive garments influence attenuation in running. 40 runners trained with compressive and placebo stockings for 3 weeks. Perception of comfort, stride parameters (rate, length) and impact acceleration (head and tibial peak acceleration, magnitude, acceleration rate and attenuation) were measured every 5 min during a fatigue run (30 min at 80% of the individual's maximal aerobic speed). Compressive stockings reduced tibial peak acceleration and magnitude compared to placebo stockings at every minute (p<0.05) except for the initial measurement (p>0.05). Moreover, compressive stockings led to a lower rate of increase in tibial peak acceleration (14%, p<0.005) and magnitude (16%, p<0.001) as a result of the development of fatigue compared to placebo stockings (24% and 26% increase, p=0.014 and p=0.003, respectively). Similar perception of comfort was reported for both garments. Training with compressive stockings for 3 weeks reduced impact acceleration and the rate of increase in acceleration compared to placebo stockings. These findings suggest that compressive stockings may play a protective role by reducing impact accelerations during running. © Georg Thieme Verlag KG Stuttgart · New York.

The influence of inertial sensor sampling frequency on the accuracy of measurement parameters in rearfoot running.

PubMed

Mitschke, Christian; Zaumseil, Falk; Milani, Thomas L

2017-11-01

Increasingly, inertial sensors are being used for running analyses. The aim of this study was to systematically investigate the influence of inertial sensor sampling frequencies (SF) on the accuracy of kinematic, spatio-temporal, and kinetic parameters. We hypothesized that running analyses at lower SF result in less signal information and therefore the inability to sufficiently interpret measurement data. Twenty-one subjects participated in this study. Rearfoot strikers ran on an indoor running track at a velocity of 3.5 ± 0.1 ms -1 . A uniaxial accelerometer was attached at the tibia and an inertial measurement unit was mounted at the heel of the right shoe. All sensors were synchronized at the start and data was measured with 1000 Hz (reference SF). Datasets were reduced to 500, 333, 250, 200, and 100 Hz in post-processing. The results of this study showed that a minimum SF of 500 Hz should be used to accurately measure kinetic parameters (e.g. peak heel acceleration). In contrast, stride length showed accurate results even at 333 Hz. 200 Hz were required to calculate parameters accurately for peak tibial acceleration, stride duration, and all kinematic measurements. The information from this study is necessary to correctly interpret measurement data of existing investigations and to plan future studies.

Effects of Perturbation-Based Slip Training using a Virtual Reality Environment on Slip-induced Falls

PubMed Central

Parijat, Prakriti; Lockhart, Thurmon E.; Liu, Jian

2015-01-01

The purpose of the current study was to design and evaluate the effectiveness of virtual reality training in improving recovery reactions and reducing fall frequency in older adults. Twenty-four older adults were recruited and randomly assigned to two groups (virtual reality training and control). Both groups underwent three sessions including baseline slip, training and transfer of training on slippery surface. Both groups experienced two slips, one during baseline and the other during the transfer of training trial. The training group underwent twelve simulated slips using a visual perturbation induced by tilting a virtual reality scene while walking on the treadmill and the control group performed normal walking during the training session. Kinematic and kinetic data were collected during all the sessions. Results demonstrated a reduced incidence of falls in the training group during the transfer of training trial as compared to the control group. The training group was able to transfer reactive control strategies learned during training to the second slip trial. The reactive adjustments included reduced slip distance. Additionally, gait parameters reflective of gait instability (stride length, step width, variability in stride velocity) reduced after walking in the VR environment for 15–20 min. The results indicated a beneficial effect of the virtual reality training in reducing slip severity and recovery kinematics in healthy older adults. PMID:25245221

Kinematic Adaptations of Forward And Backward Walking on Land and in Water

PubMed Central

Cadenas-Sanchez, Cristina; Arellano, Raúl; Vanrenterghem, Jos; López-Contreras, Gracia

2015-01-01

The aim of this study was to compare sagittal plane lower limb kinematics during walking on land and submerged to the hip in water. Eight healthy adults (age 22.1 ± 1.1 years, body height 174.8 ± 7.1 cm, body mass 63.4 ± 6.2 kg) were asked to cover a distance of 10 m at comfortable speed with controlled step frequency, walking forward or backward. Sagittal plane lower limb kinematics were obtained from three dimensional video analysis to compare spatiotemporal gait parameters and joint angles at selected events using two-way repeated measures ANOVA. Key findings were a reduced walking speed, stride length, step length and a support phase in water, and step length asymmetry was higher compared to the land condition (p<0.05). At initial contact, knees and hips were more flexed during walking forward in water, whilst, ankles were more dorsiflexed during walking backward in water. At final stance, knees and ankles were more flexed during forward walking, whilst the hip was more flexed during backward walking. These results show how walking in water differs from walking on land, and provide valuable insights into the development and prescription of rehabilitation and training programs. PMID:26839602

Insights into gait disorders: walking variability using phase plot analysis, Huntington's disease.

PubMed

Collett, Johnny; Esser, Patrick; Khalil, Hanan; Busse, Monica; Quinn, Lori; DeBono, Katy; Rosser, Anne; Nemeth, Andrea H; Dawes, Helen

2014-09-01

Huntington's disease (HD) is a progressive inherited neurodegenerative disorder. Identifying sensitive methodologies to quantitatively measure early motor changes have been difficult to develop. This exploratory observational study investigated gait variability and symmetry in HD using phase plot analysis. We measured the walking of 22 controls and 35 HD gene carriers (7 premanifest (PreHD)), 16 early/mid (HD1) and 12 late stage (HD2) in Oxford and Cardiff, UK. The unified Huntington's disease rating scale-total motor scores (UHDRS-TMS) and disease burden scores (DBS) were used to quantify disease severity. Data was collected during a clinical walk test (8.8 or 10 m) using an inertial measurement unit attached to the trunk. The 6 middle strides were used to calculate gait variability determined by spatiotemporal parameters (co-efficient of variation (CoV)) and phase plot analysis. Phase plots considered the variability in consecutive wave forms from vertical movement and were quantified by SDA (spatiotemporal variability), SDB (temporal variability), ratio ∀ (ratio SDA:SDB) and Δangleβ (symmetry). Step time CoV was greater in manifest HD (p<0.01, both manifest groups) than controls, as was stride length CoV for HD2 (p<0.01). No differences were found in spatiotemporal variability between PreHD and controls (p>0.05). Phase plot analysis identified differences between manifest HD and controls for SDB, Ratio ∀ and Δangle (all p<0.01, both manifest groups). Furthermore Ratio ∀ was smaller in PreHD compared with controls (p<0.01). Ratio ∀ also produced the strongest correlation with UHDRS-TMS (r=-0.61, p<0.01) and was correlated with DBS (r=-0.42, p=0.02). Phase plot analysis may be a sensitive method of detecting gait changes in HD and can be performed quickly during clinical walking tests. Copyright © 2014 Elsevier B.V. All rights reserved.

Core stabilization exercise with real-time feedback for chronic hemiparetic stroke: a pilot randomized controlled trials.

PubMed

Chung, Eunjung; Lee, Byoung-Hee; Hwang, Sujin

2014-01-01

The purpose of this study was to examine the feasibility of core stabilization exercise with real-time feedback on balance and gait function in patients with chronic hemiparetic stroke. Nineteen stroke subjects were enrolled in this study. The patients were randomly divided into the experimental (n = 10) and control groups (n = 9). Subjects in the experimental group performed core stabilization exercise with real-time feedback training for 30 minutes per day during a period of six weeks. Subjects in the control group performed core stabilization exercise during the same period. This study assessed the kinematic parameters using a portable walkway system, and timed up-and-go test. Gait velocity showed significantly greater improvement in the experimental group (7.3 ± 5.0 sec) than in the control group (-0.7 ± 10.6). Stride length showed significantly greater increase in the experimental group (13.2 ± 7.9 on the affected side and 12.6 ± 8.0 on the less affected side) than the control group (3.5 ± 8.7 on the affected side and 3.4 ± 8.5 on the less affected side). After training, change in results on the timed up and go test was significantly greater in the experimental group than in the control group. Core stabilization exercise using real-time feedback produces greater improvement in gait performance in chronic hemiparetic stroke patients than core stabilization exercise only.

Body stability and muscle and motor cortex activity during walking with wide stance

PubMed Central

Farrell, Brad J.; Bulgakova, Margarita A.; Beloozerova, Irina N.; Sirota, Mikhail G.

2014-01-01

Biomechanical and neural mechanisms of balance control during walking are still poorly understood. In this study, we examined the body dynamic stability, activity of limb muscles, and activity of motor cortex neurons [primarily pyramidal tract neurons (PTNs)] in the cat during unconstrained walking and walking with a wide base of support (wide-stance walking). By recording three-dimensional full-body kinematics we found for the first time that during unconstrained walking the cat is dynamically unstable in the forward direction during stride phases when only two diagonal limbs support the body. In contrast to standing, an increased lateral between-paw distance during walking dramatically decreased the cat's body dynamic stability in double-support phases and prompted the cat to spend more time in three-legged support phases. Muscles contributing to abduction-adduction actions had higher activity during stance, while flexor muscles had higher activity during swing of wide-stance walking. The overwhelming majority of neurons in layer V of the motor cortex, 82% and 83% in the forelimb and hindlimb representation areas, respectively, were active differently during wide-stance walking compared with unconstrained condition, most often by having a different depth of stride-related frequency modulation along with a different mean discharge rate and/or preferred activity phase. Upon transition from unconstrained to wide-stance walking, proximal limb-related neuronal groups subtly but statistically significantly shifted their activity toward the swing phase, the stride phase where most of body instability occurs during this task. The data suggest that the motor cortex participates in maintenance of body dynamic stability during locomotion. PMID:24790167

Gait analysis in patients operated on for sacrococcygeal teratoma.

PubMed

Zaccara, Antonio; Iacobelli, Barbara D; Adorisio, Ottavio; Petrarca, Maurizio; Di Rosa, Giuseppe; Pierro, Marcello M; Bagolan, Pietro

2004-06-01

Long-term follow-up of sacrococcygeal teratoma (SCT) is well established; however, little is known about the effects of extensive surgery in the pelvic and perineal region, which involves disruption of muscles providing maximal support in normal walking. Thirteen patients operated on at birth for SCT with extensive muscle dissection underwent gait studies with a Vicon 3-D motion analysis system with 6 cameras. Results were compared with 15 age-matched controls. Statistical analysis was performed with Mann-Whitney test; correlations were sought with Spearman's correlation coefficient. All subjects were independent ambulators, and no statistically significant differences were seen in walking velocity and stride length. However, in all patients, toe-off occurred earlier (at 58% +/- 1.82% of stride length) than controls (at 65.5% +/- 0.52%; P <.05). On kinetics, all patients exhibited, on both limbs, a significant reduction of hip extensory moment (-0.11 +/- 0.11 left; -0.16 +/- 0.15 right v 1.19 +/- 0.08 Newtonmeter/kg; P <.05) and of ankle dorsi/plantar moment (-0.07 +/- 0.09 right; -0.08 +/- 0.16 v -0.15 +/- 0.05 Nm/kg, p < 0.05). Knee power was also significantly reduced (0.44 +/- 0.55 right, 0.63 +/- 0.45 left v 0.04 +/- 0.05 W/kg), whereas ankle power was increased (3 +/- 1.5 right; 2.8 +/- 0.9 left v 1.97 +/- 0.2 W/kg; P <.05). No statistically significant correlation was found between tumor size and either muscle power generation or flexory/extensory moments. Patients operated on for SCT exhibit nearly normal gait patterns. However, this normal pattern is accompanied by abnormal kinetics of some ambulatory muscles, and the extent of these abnormalities appears to be independent of tumor size. A careful follow-up is warranted to verify if such modifications are stable or progress over the years, thereby impairing ambulatory potential or leading to early arthrosis.

Combined Dual-Task Gait Training and Aerobic Exercise to Improve Cognition, Mobility, and Vascular Health in Community-Dwelling Older Adults at Risk for Future Cognitive Decline1.

PubMed

Gregory, Michael A; Boa Sorte Silva, Narlon C; Gill, Dawn P; McGowan, Cheri L; Liu-Ambrose, Teresa; Shoemaker, J Kevin; Hachinski, Vladimir; Holmes, Jeff; Petrella, Robert J

2017-01-01

This 6-month experimental case series study investigated the effects of a dual-task gait training and aerobic exercise intervention on cognition, mobility, and cardiovascular health in community-dwelling older adults without dementia. Participants exercised 40 min/day, 3 days/week for 26 weeks on a Biodex GaitTrainer2 treadmill. Participants were assessed at baseline (V0), interim (V1: 12-weeks), intervention endpoint (V2: 26-weeks), and study endpoint (V3: 52-weeks). The study outcomes included: cognition [executive function (EF), processing speed, verbal fluency, and memory]; mobility: usual & dual-task gait (speed, step length, and stride time variability); and vascular health: ambulatory blood pressure, carotid arterial compliance, and intima-media thickness (cIMT). Fifty-six participants [age: 70(6) years; 61% female] were included in this study. Significant improvements following the exercise program (V2) were observed in cognition: EF (p = 0.002), processing speed (p < 0.001), verbal fluency [digit symbol coding (p < 0.001), phonemic verbal fluency (p < 0.001)], and memory [immediate recall (p < 0.001) and delayed recall (p < 0.001)]; mobility: usual & dual-task gait speed (p = 0.002 and p < 0.001, respectively) and step length (p = 0.001 and p = 0.003, respectively); and vascular health: cIMT (p = 0.002). No changes were seen in the remaining outcomes. In conclusion, 26 weeks of dual-task gait training and aerobic exercise improved performance on a number of cognitive outcomes, while increasing usual & dual-task gait speed and step length in a sample of older adults without dementia.

A Surgical Model of Posttraumatic Osteoarthritis With Histological and Gait Validation.

PubMed

Zahoor, Talal; Mitchell, Reed; Bhasin, Priya; Schon, Lew; Zhang, Zijun

2016-07-01

Posttraumatic osteoarthritis (PTOA) is secondary to an array of joint injuries. Animal models are useful tools for addressing the uniqueness of PTOA progression in each type of joint injury and developing strategies for PTOA prevention and treatment. Intra-articular fracture induces PTOA pathology. Descriptive laboratory study. Through a parapatellar incision, the medial tibial plateau was exposed in the left knees of 8 Sprague-Dawley rats. Osteotomy at the midpoint between the tibial crest and the outermost portion of the medial tibial plateau, including the covering articular cartilage, was performed using a surgical blade. The fractured medial tibial plateau was fixed with 2 needles transversely. The fractured knees were not immobilized. Before and after surgery, rat gait was recorded. Rats were sacrificed at week 8, and their knees were harvested for histology. After intra-articular fracture, the affected limbs altered gait from baseline (week 0). In the first 2 weeks, the gait of the operated limbs featured a reduced paw print intensity and stride length but increased maximal contact and stance time. Reduction of maximal and mean print area and duty cycle (the percentage of stance phase in a step) was present from week 1 to week 5. Only print length was reduced in weeks 7 and 8. At week 8, histology of the operated knees demonstrated osteoarthritic pathology. The severity of the PTOA pathology did not correlate with the changes of print length at week 8. Intra-articular fracture of the medial tibial plateau effectively induced PTOA in rat knees. During PTOA development, the injured limbs demonstrated characteristic gait. Intra-articular fracture represents severe joint injury and associates with a high rate of PTOA. This animal model, with histologic and gait validations, can be useful for future studies of PTOA prevention and early diagnosis.

Kinematic variability, fractal dynamics and local dynamic stability of treadmill walking

PubMed Central

2011-01-01

Background Motorized treadmills are widely used in research or in clinical therapy. Small kinematics, kinetics and energetics changes induced by Treadmill Walking (TW) as compared to Overground Walking (OW) have been reported in literature. The purpose of the present study was to characterize the differences between OW and TW in terms of stride-to-stride variability. Classical (Standard Deviation, SD) and non-linear (fractal dynamics, local dynamic stability) methods were used. In addition, the correlations between the different variability indexes were analyzed. Methods Twenty healthy subjects performed 10 min TW and OW in a random sequence. A triaxial accelerometer recorded trunk accelerations. Kinematic variability was computed as the average SD (MeanSD) of acceleration patterns among standardized strides. Fractal dynamics (scaling exponent α) was assessed by Detrended Fluctuation Analysis (DFA) of stride intervals. Short-term and long-term dynamic stability were estimated by computing the maximal Lyapunov exponents of acceleration signals. Results TW did not modify kinematic gait variability as compared to OW (multivariate T2, p = 0.87). Conversely, TW significantly modified fractal dynamics (t-test, p = 0.01), and both short and long term local dynamic stability (T2 p = 0.0002). No relationship was observed between variability indexes with the exception of significant negative correlation between MeanSD and dynamic stability in TW (3 × 6 canonical correlation, r = 0.94). Conclusions Treadmill induced a less correlated pattern in the stride intervals and increased gait stability, but did not modify kinematic variability in healthy subjects. This could be due to changes in perceptual information induced by treadmill walking that would affect locomotor control of the gait and hence specifically alter non-linear dependencies among consecutive strides. Consequently, the type of walking (i.e. treadmill or overground) is important to consider in each protocol design. PMID:21345241

A PDF-based classification of gait cadence patterns in patients with amyotrophic lateral sclerosis.

PubMed

Wu, Yunfeng; Ng, Sin Chun

2010-01-01

Amyotrophic lateral sclerosis (ALS) is a type of neurological disease due to the degeneration of motor neurons. During the course of such a progressive disease, it would be difficult for ALS patients to regulate normal locomotion, so that the gait stability becomes perturbed. This paper presents a pilot statistical study on the gait cadence (or stride interval) in ALS, based on the statistical analysis method. The probability density functions (PDFs) of stride interval were first estimated with the nonparametric Parzen-window method. We computed the mean of the left-foot stride interval and the modified Kullback-Leibler divergence (MKLD) from the PDFs estimated. The analysis results suggested that both of these two statistical parameters were significantly altered in ALS, and the least-squares support vector machine (LS-SVM) may effectively distinguish the stride patterns between the ALS patients and healthy controls, with an accurate rate of 82.8% and an area of 0.87 under the receiver operating characteristic curve.

A hetero-core fiber optic smart mat sensor for discrimination between a moving human and object on temporal loss peaks

NASA Astrophysics Data System (ADS)

Hosoki, Ai; Nishiyama, Michiko; Choi, Yongwoon; Watanabe, Kazuhiro

2011-05-01

In this paper, we propose discrimination method between a moving human and object by means of a hetero-core fiber smart mat sensor which induces the optical loss change in time. In addition to several advantages such as flexibility, thin size and resistance to electro-magnetic interference for a fiber optic sensor, a hetero-core fiber optic sensor is sensitive to bending action of the sensor portion and independent of temperature fluctuations. Therefore, the hetero-core fiber thin mat sensor can have a fewer sensing portions than the conventional floor pressure sensors, furthermore, can detect the wide area covering the length of strides. The experimental results for human walking tests showed that the mat sensors were reproducibly working in real-time under limiting locations the foot passed in the mat sensor. Focusing on the temporal peak numbers in the optical loss, human walking and wheeled platform moving action induced the peak numbers in the range of 1 - 3 and 5 - 7, respectively, for the 10 persons including 9 male and 1 female. As a result, we conclude that the hetero-core fiber mat sensor is capable of discriminating between the moving human and object such as a wheeled platform focusing on the peak numbers in the temporal optical loss.

A comparative study of the effects of trunk exercise program in aquatic and land-based therapy on gait in hemiplegic stroke patients

PubMed Central

Park, Byoung-Sun; Noh, Ji-Woong; Kim, Mee-Young; Lee, Lim-Kyu; Yang, Seung-Min; Lee, Won-Deok; Shin, Yong-Sub; Kim, Ju-Hyun; Lee, Jeong-Uk; Kwak, Taek-Yong; Lee, Tae-Hyun; Park, Jaehong; Kim, Junghwan

2016-01-01

[Purpose] The purpose of this study was to compare the effects of aquatic and land-based trunk exercise program on gait in stroke patients. [Subjects and Methods] The subjects were 28 hemiplegic stroke patients (20 males, 8 females). The subjects performed a trunk exercise program for a total of four weeks. [Results] Walking speed and cycle, stance phase and stride length of the affected side, and the symmetry index of the stance phase significantly improved after the aquatic and land-based trunk exercise program. [Conclusion] These results suggest that the aquatic and land-based trunk exercise program may help improve gait performance ability after stroke. PMID:27390444

Effects of progressive backward body weight suppoted treadmill training on gait ability in chronic stroke patients: A randomized controlled trial.

PubMed

Kim, Kyung Hun; Lee, Kyoung Bo; Bae, Young-Hyeon; Fong, Shirley S M; Lee, Suk Min

2017-10-23

A stroke patient with hemiplegic gait is generally described as being slow and asymmetric. Body weight-supported treadmill training and backward gait training are recent additions to therapeutic gait trainings that may help improve gait in stroke patient with hemiplegic gait. Therefore, we examined the effect of progressive backward body weight-supported treadmill training on gait in chronic stroke patients with hemiplegic gait. Thirty subjects were divided to the experimental and control groups. The experimental group consisted of 15 patients and underwent progressive backward body weight-supported treadmill training. The control group consisted of 15 patients and underwent general treadmill gait training five times per week, for a total of four weeks. The OptoGait was used to analyze gait kinematics, and the dynamic gait index (DGI) and results of the 6-minute walk test were used as the clinical evaluation indicators. A follow-up test was carried out four weeks later to examine persistence of exercise effects. The experimental group showed statistically significant results in all dependent variables week four compared to the control group. However, until the eighth week, only the dependent variables, of affected step length (ASL), stride length (SL), and DGI differed significantly between the two groups. This study verified that progressive bodyweight-supported treadmill training had a positive influence on the temporospatial characteristics of gait and clinical gait evaluation index in chronic stroke patients.

Adaptive changes in spatiotemporal gait characteristics in women during pregnancy.

PubMed

Błaszczyk, Janusz W; Opala-Berdzik, Agnieszka; Plewa, Michał

2016-01-01

Spatiotemporal gait cycle characteristics were assessed at early (P1), and late (P2) pregnancy, as well as at 2 months (PP1) and 6 months (PP2) postpartum. A substantial decrease in walking speed was observed throughout the pregnancy, with the slowest speed (1±0.2m/s) being during the third trimester. Walking at slower velocity resulted in complex adaptive adjustments to their spatiotemporal gait pattern, including a shorter step length and an increased duration of both their stance and double-support phases. Duration of the swing phase remained the least susceptible to changes. Habitual walking velocity (1.13±0.2m/s) and the optimal gait pattern were fully recovered 6 months after childbirth. Documented here adaptive changes in the preferred gait pattern seem to result mainly from the altered body anthropometry leading to temporary balance impairments. All the observed changes within stride cycle aimed to improve gait safety by focusing on its dynamic stability. The pregnant women preferred to walk at a slower velocity which allowed them to spend more time in double-support compared with their habitual pattern. Such changes provided pregnant women with a safer and more tentative ambulation that reduced the single-support period and, hence, the possibility of instability. As pregnancy progressed a significant increase in stance width and a decrease in step length was observed. Both factors allow also for gait stability improvement. Copyright © 2015 Elsevier B.V. All rights reserved.

Robot-assisted walking training for individuals with Parkinson's disease: a pilot randomized controlled trial.

PubMed

Sale, Patrizio; De Pandis, Maria Francesca; Le Pera, Domenica; Sova, Ivan; Cimolin, Veronica; Ancillao, Andrea; Albertini, Giorgio; Galli, Manuela; Stocchi, Fabrizio; Franceschini, Marco

2013-05-24

Over the last years, the introduction of robotic technologies into Parkinson's disease rehabilitation settings has progressed from concept to reality. However, the benefit of robotic training remains elusive. This pilot randomized controlled observer trial is aimed at investigating the feasibility, the effectiveness and the efficacy of new end-effector robot training in people with mild Parkinson's disease. Design. Pilot randomized controlled trial. Robot training was feasible, acceptable, safe, and the participants completed 100% of the prescribed training sessions. A statistically significant improvement in gait index was found in favour of the EG (T0 versus T1). In particular, the statistical analysis of primary outcome (gait speed) using the Friedman test showed statistically significant improvements for the EG (p = 0,0195). The statistical analysis performed by Friedman test of Step length left (p = 0,0195) and right (p = 0,0195) and Stride length left (p = 0,0078) and right (p = 0,0195) showed a significant statistical gain. No statistically significant improvements on the CG were found. Robot training is a feasible and safe form of rehabilitative exercise for cognitively intact people with mild PD. This original approach can contribute to increase a short time lower limb motor recovery in idiopathic PD patients. The focus on the gait recovery is a further characteristic that makes this research relevant to clinical practice. On the whole, the simplicity of treatment, the lack of side effects, and the positive results from patients support the recommendation to extend the use of this treatment. Further investigation regarding the long-time effectiveness of robot training is warranted. ClinicalTrials.gov NCT01668407.

Gait disorders in the elderly and dual task gait analysis: a new approach for identifying motor phenotypes.

PubMed

Auvinet, Bernard; Touzard, Claude; Montestruc, François; Delafond, Arnaud; Goeb, Vincent

2017-01-31

Gait disorders and gait analysis under single and dual-task conditions are topics of great interest, but very few studies have looked for the relevance of gait analysis under dual-task conditions in elderly people on the basis of a clinical approach. An observational study including 103 patients (mean age 76.3 ± 7.2, women 56%) suffering from gait disorders or memory impairment was conducted. Gait analysis under dual-task conditions was carried out for all patients. Brain MRI was performed in the absence of contra-indications. Three main gait variables were measured: walking speed, stride frequency, and stride regularity. For each gait variable, the dual task cost was computed and a quartile analysis was obtained. Nonparametric tests were used for all the comparisons (Wilcoxon, Kruskal-Wallis, Fisher or Chi 2 tests). Four clinical subgroups were identified: gait instability (45%), recurrent falls (29%), memory impairment (18%), and cautious gait (8%). The biomechanical severity of these subgroups was ordered according to walking speed and stride regularity under both conditions, from least to most serious as follows: memory impairment, gait instability, recurrent falls, cautious gait (p < 0.01 for walking speed, p = 0.05 for stride regularity). According to the established diagnoses of gait disorders, 5 main pathological subgroups were identified (musculoskeletal diseases (n = 11), vestibular diseases (n = 6), mild cognitive impairment (n = 24), central nervous system pathologies, (n = 51), and without diagnosis (n = 8)). The dual task cost for walking speed, stride frequency and stride regularity were different among these subgroups (p < 0.01). The subgroups mild cognitive impairment and central nervous system pathologies both showed together a higher dual task cost for each variable compared to the other subgroups combined (p = 0.01). The quartile analysis of dual task cost for stride frequency and stride regularity allowed the identification of 3 motor phenotypes (p < 0.01), without any difference for white matter hyperintensities, but with an increased Scheltens score from the first to the third motor phenotype (p = 0.05). Gait analysis under dual-task conditions in elderly people suffering from gait disorders or memory impairment is of great value in assessing the severity of gait disorders, differentiating between peripheral pathologies and central nervous system pathologies, and identifying motor phenotypes. Correlations between motor phenotypes and brain imaging require further studies.

Supported treadmill ambulation for amyotrophic lateral sclerosis: a pilot study.

PubMed

Sanjak, Mohammed; Bravver, Elena; Bockenek, William L; Norton, H James; Brooks, Benjamin R

2010-12-01

To determine the feasibility, tolerability, safety, and exercise treatment-effect size of repetitive rhythmic exercise mediated by supported treadmill ambulation training (STAT) for patients with amyotrophic lateral sclerosis (ALS). Interventional with repeated-measures design. Multidisciplinary ALS clinic at academic medical center. Convenience sample of patients with ALS (N=9) who were ambulatory with assistive devices (Sinaki-Mulder stages II-III). Repetitive rhythmic exercise-STAT (30min total; 5min of exercise intercalated with 5min of rest) performed 3 times a week for 8 weeks. ALS Functional Rating Scale-Revised (ALSFRS-R), percentage of predicted vital capacity (VC), total lower-extremities manual muscle test (MMT), rate of perceived exertion (RPE), Fatigue Severity Scale (FSS), and maximum voluntary isometric contraction (MVIC) in 10 lower and 10 upper extremities. Gait performance, which included walking distance, speed, steps, and stride length, was evaluated during treadmill and ground 6-minute walk tests (6MWTs) and 25-foot walk test (25FWT). Feasibility issues decreased screened participants by 4 patients (31%). Nine patients were enrolled, but 6 patients (67%) completed the study and 3 (23% of original cohort; 33% of enrolled cohort) could not complete the exercise intervention because of non-ALS-related medical problems. Tolerability of the intervention measures during the treadmill 6MWT showed improvement in RPE (P≤.05) and FSS score (P≥.05). Safety measures (ALSFRS-R, VC, MMT) showed no decrease and showed statistical improvement in ALSFRS-R score (P≤.05) during the study interval. Exercise treatment-effect size showed variable improvements. Gait speed, distance, and stride length during the treadmill 6MWT improved significantly (P≤.05) after 4 weeks and improvements were maintained after 8 weeks compared with baseline. Walking distance during the ground 6MWT increased significantly after 4 weeks and was maintained after 8 weeks compared with baseline (P≤.05). Walking speed during the 25FWT and lower-extremity MVIC improved, but were not statistically significant. Repetitive rhythmic exercise-STAT is feasible, tolerated, and safe for patients with ALS. Repetitive rhythmic exercise-STAT treatment-effect size across a number of ALS-related measures was consistent with improved work capacity and gait function in patients with ALS who are dependent on assistive devices for ambulation. Repetitive rhythmic exercise-STAT should be evaluated further in larger studies to determine the stability of this improved function in relation to the rate of progression of the underlying ALS. Copyright © 2010 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

28 CFR 16.98 - Exemption of the Drug Enforcement Administration (DEA)-limited access.

Code of Federal Regulations, 2012 CFR

2012-07-01

... (Justice/DEA-013) (7) System to Retrieve Information from Drug Evidence (STRIDE/Ballistics) (Justice/DEA... Retrieve Information from Drug Evidence (STRIDE/Ballistics) (Justice/DEA-014) only to the extent that..., implemented internal quality assurance procedures to ensure that ESS data is as thorough, accurate, and...

28 CFR 16.98 - Exemption of the Drug Enforcement Administration (DEA)-limited access.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (Justice/DEA-013) (7) System to Retrieve Information from Drug Evidence (STRIDE/Ballistics) (Justice/DEA... Retrieve Information from Drug Evidence (STRIDE/Ballistics) (Justice/DEA-014) only to the extent that..., implemented internal quality assurance procedures to ensure that ESS data is as thorough, accurate, and...

School Choice Marches forward

ERIC Educational Resources Information Center

Butcher, Jonathan

2013-01-01

One year ago, the "Wall Street Journal" dubbed 2011 "the year of school choice," opining that "this year is shaping up as the best for reformers in a very long time." School-choice laws took great strides in 2011, both in the number of programs that succeeded across states and also in the size and scope of the adopted…

Influence of running stride frequency in heart rate variability analysis during treadmill exercise testing.

PubMed

Bailón, Raquel; Garatachea, Nuria; de la Iglesia, Ignacio; Casajús, Jose Antonio; Laguna, Pablo

2013-07-01

The analysis and interpretation of heart rate variability (HRV) during exercise is challenging not only because of the nonstationary nature of exercise, the time-varying mean heart rate, and the fact that respiratory frequency exceeds 0.4 Hz, but there are also other factors, such as the component centered at the pedaling frequency observed in maximal cycling tests, which may confuse the interpretation of HRV analysis. The objectives of this study are to test the hypothesis that a component centered at the running stride frequency (SF) appears in the HRV of subjects during maximal treadmill exercise testing, and to study its influence in the interpretation of the low-frequency (LF) and high-frequency (HF) components of HRV during exercise. The HRV of 23 subjects during maximal treadmill exercise testing is analyzed. The instantaneous power of different HRV components is computed from the smoothed pseudo-Wigner-Ville distribution of the modulating signal assumed to carry information from the autonomic nervous system, which is estimated based on the time-varying integral pulse frequency modulation model. Besides the LF and HF components, the appearance is revealed of a component centered at the running SF as well as its aliases. The power associated with the SF component and its aliases represents 22±7% (median±median absolute deviation) of the total HRV power in all the subjects. Normalized LF power decreases as the exercise intensity increases, while normalized HF power increases. The power associated with the SF does not change significantly with exercise intensity. Consideration of the running SF component and its aliases is very important in HRV analysis since stride frequency aliases may overlap with LF and HF components.

Falls, Cognitive Impairment, and Gait Performance: Results From the GOOD Initiative

PubMed Central

Allali, Gilles; Launay, Cyrille P.; Blumen, Helena M.; Callisaya, Michele L.; De Cock, Anne-Marie; Kressig, Reto W.; Srikanth, Velandai; Steinmetz, Jean-Paul; Verghese, Joe; Beauchet, Olivier

2017-01-01

Objectives Falls are highly prevalent in individuals with cognitive decline. The complex relationship between falls and cognitive decline (including both subtype and severity of dementia) and the influence of gait disorders have not been studied. This study aimed to examine the association between the subtype (Alzheimer disease [AD] versus non-AD) and the severity (from preclinical to moderate dementia) of cognitive impairment and falls, and to establish an association between falls and gait parameters during the course of dementia. Design Multicenter cross-sectional study. Setting “Gait, cOgnitiOn & Decline” (GOOD) initiative. Participants A total of 2496 older adults (76.6 ± 7.6 years; 55.0% women) were included in this study (1161 cognitively healthy individuals [CHI], 529 patients with mild cognitive impairment [MCI], 456 patients with mild dementia, and 350 with moderate dementia) from 7 countries. Measurements Falls history was collected retrospectively at baseline in each study. Gait speed and stride time variability were recorded at usual walking pace with the GAITRite system. Results The prevalence of individuals who fall was 50% in AD and 64% in non-AD; whereas it was 25% in CHIs. Only mild and moderate non-AD dementia were associated with an increased risk for falls in comparison with CHI. Higher stride time variability was associated with falls in older adults without dementia (CHI and each MCI subgroup) and mild non-AD dementia, whereas lower gait speed was associated with falls in all participant groups, except in mild AD dementia. When gait speed was adjusted for, higher stride time variability was associated with falls only in CHIs (odds ratio 1.14; P = .012), but not in MCI or in patients with dementia. Conclusions These findings suggest that non-AD, but not AD dementia, is associated with increased falls in comparison with CHIs. The association between gait parameters and falls also differs across cognitive status, suggesting different mechanisms leading to falls in older individuals with dementia in comparison with CHIs who fall. PMID:27914848

Pontine norepinephrine content after motor cortical ablation in rats.

PubMed

Gonzalez-Pina, Rigoberto; Bueno-Nava, Antonio; Montes, Sergio; Alfaro-Rodriguez, Alfonso; Gonzalez-Maciel, Angélica; Reynoso-Robles, Rafael; Ayala-Guerrero, Fructuoso

2005-01-01

It has been reported that norepinephrine (NE) plays an important role in recovery after brain damage. However, the role of the pons, the site where the norepinephrinergic locus coeruleus (LC) is located, has not been elucidated. In order to study the changes in the pontine NE content in either noninjured, injured or recovered rats, we used 35 animals trained to walk across to a walkway where their footprints were recorded. Subsequently, 17 trained rats were sham-operated while 18 were injured by means of an ablation of the right motor cortex representative of the hindlimb. From the injured rats, 6 were sacrificed 6 hr before surgery in order to obtain the pons, while all the remaining rats were recorded in the walkway 6, 24 and 48 hr post-surgery. Then, rats were sacrificed by decapitation, the pons was removed and each hemisphere was prepared for the chromatographic analysis of NE. Results showed that after cortical brain damage, the length of the stride decreased while the angle of the stride increased 6 hr post-surgery. Recovery was observed after 24 hr. NE increased in the pons after 6 hr and returned to normal levels when rats had recovered. This suggests that cortical damage elicits NE changes in the LC that could reorganize the system to lead the recovery process. Such findings must be taken in account when pharmacotherapy with antidepressants or antipsychotics that act on norepinephrine-containing neuronal systems are prescribed in patients after stroke.

How to find home backwards? Locomotion and inter-leg coordination during rearward walking of Cataglyphis fortis desert ants.

PubMed

Pfeffer, Sarah E; Wahl, Verena L; Wittlinger, Matthias

2016-07-15

For insects, flexibility in the performance of terrestrial locomotion is a vital part of facing the challenges of their often unpredictable environment. Arthropods such as scorpions and crustaceans can switch readily from forward to backward locomotion, but in insects this behaviour seems to be less common and, therefore, is only poorly understood. Here we present an example of spontaneous and persistent backward walking in Cataglyphis desert ants that allows us to investigate rearward locomotion within a natural context. When ants find a food item that is too large to be lifted up and to be carried in a normal forward-faced orientation, they will drag the load walking backwards to their home nest. A detailed examination of this behaviour reveals a surprising flexibility of the locomotor output. Compared with forward walks with regular tripod coordination, no main coordination pattern can be assigned to rearward walks. However, we often observed leg-pair-specific stepping patterns. The front legs frequently step with small stride lengths, while the middle and the hind legs are characterized by less numerous but larger strides. But still, these specializations show no rigidly fixed leg coupling, nor are they strictly embedded within a temporal context; therefore, they do not result in a repetitive coordination pattern. The individual legs act as separate units, most likely to better maintain stability during backward dragging. © 2016. Published by The Company of Biologists Ltd.

Diagonal gaits in the feathertail glider Acrobates pygmaeus (Acrobatidae, Diprotodontia): Insights for the evolution of primate quadrupedalism.

PubMed

Karantanis, Nikolaos-Evangelos; Youlatos, Dionisios; Rychlik, Leszek

2015-09-01

Research on primate origins has revolved around arboreality and, more specifically, the adaptations that are linked to safe navigation in the fine-branch niche. To this end, extant non-primate mammals have been used as models to assess the significance of these adaptations. However, the size of these models is larger than that estimated for early primates. In contrast, the feathertail marsupial glider Acrobates pygmaeus, with a body mass of 12 g, a clawless opposable hallux, and terminal branch feeding habits appears more suited to modeling behavioral adaptations to the small branch milieu. Analysis of video recordings of 18 feathertail gliders walking on poles of variable diameter and inclination revealed that they preferentially used diagonal sequence gaits, fast velocities and low duty factors. Diagonal gaits did not correlate to duty factor, but increased as substrate size decreased, and from descending to ascending locomotion. Furthermore, the duty factor index increased in more diagonal gaits and ascending locomotion. Finally, velocities were lower on smaller substrates, and were mainly regulated by stride frequency and, to a lesser degree, stride length. Feathertail glider gaits displayed noteworthy behavioral convergences with primate quadrupedalism, but some of these results need additional investigation. Despite any discrepancies, these features appear to be favorable for quadrupedal progression on small branches, providing a selective advantage for navigating within a fine branch niche and highlighting the importance of small body size in early primate evolution. Copyright © 2015 Elsevier Ltd. All rights reserved.

Comparison of three-dimensional lower extremity running kinematics of young adult and elderly runners.

PubMed

Fukuchi, Reginaldo K; Duarte, Marcos

2008-11-01

The objective of this study was to compare the three-dimensional lower extremity running kinematics of young adult runners and elderly runners. Seventeen elderly adults (age 67-73 years) and 17 young adults (age 26-36 years) ran at 3.1 m x s(-1) on a treadmill while the movements of the lower extremity during the stance phase were recorded at 120 Hz using three-dimensional video. The three-dimensional kinematics of the lower limb segments and of the ankle and knee joints were determined, and selected variables were calculated to describe the movement. Our results suggest that elderly runners have a different movement pattern of the lower extremity from that of young adults during the stance phase of running. Compared with the young adults, the elderly runners had a substantial decrease in stride length (1.97 vs. 2.23 m; P = 0.01), an increase in stride frequency (1.58 vs. 1.37 Hz; P = 0.002), less knee flexion/extension range of motion (26 vs. 33 degrees ; P = 0.002), less tibial internal/external rotation range of motion (9 vs. 12 degrees ; P < 0.001), larger external rotation angle of the foot segment (toe-out angle) at the heel strike (-5.8 vs. -1.0 degrees ; P = 0.009), and greater asynchronies between the ankle and knee movements during running. These results may help to explain why elderly individuals could be more susceptible to running-related injuries.

Changes in leg spring behaviour, plantar loading and foot mobility magnitude induced by an exhaustive treadmill run in adolescent middle-distance runners.

PubMed

Fourchet, François; Girard, Olivier; Kelly, Luke; Horobeanu, Cosmin; Millet, Grégoire P

2015-03-01

This study aimed to determine adjustments in spring-mass model characteristics, plantar loading and foot mobility induced by an exhaustive run. Within-participants repeated measures. Eleven highly-trained adolescent middle-distance runners ran to exhaustion on a treadmill at a constant velocity corresponding to 95% of velocity associated with VO₂max (17.8 ± 1.4 kmh(-1), time to exhaustion=8.8 ± 3.4 min). Contact time obtained from plantar pressure sensors was used to estimate spring-mass model characteristics, which were recorded (during 30 s) 1 min after the start and prior to exhaustion using pressure insoles. Foot mobility magnitude (a composite measure of vertical and medial-lateral mobility of the midfoot) was measured before and after the run. Mean contact area (foot to ground), contact time, peak vertical ground reaction force, centre of mass vertical displacement and leg compression increased significantly with fatigue, while flight time, leg stiffness and mean pressure decreased. Leg stiffness decreased because leg compression increased to a larger extent than peak vertical ground reaction forces. Step length, step frequency and foot mobility magnitude did not change at exhaustion. The stride pattern of adolescents when running on a treadmill at high constant velocity deteriorates near exhaustion, as evidenced by impaired leg-spring behaviour (leg stiffness) and altered plantar loading. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

When human walking becomes random walking: fractal analysis and modeling of gait rhythm fluctuations

NASA Astrophysics Data System (ADS)

Hausdorff, Jeffrey M.; Ashkenazy, Yosef; Peng, Chang-K.; Ivanov, Plamen Ch.; Stanley, H. Eugene; Goldberger, Ary L.

2001-12-01

We present a random walk, fractal analysis of the stride-to-stride fluctuations in the human gait rhythm. The gait of healthy young adults is scale-free with long-range correlations extending over hundreds of strides. This fractal scaling changes characteristically with maturation in children and older adults and becomes almost completely uncorrelated with certain neurologic diseases. Stochastic modeling of the gait rhythm dynamics, based on transitions between different “neural centers”, reproduces distinctive statistical properties of the gait pattern. By tuning one model parameter, the hopping (transition) range, the model can describe alterations in gait dynamics from childhood to adulthood - including a decrease in the correlation and volatility exponents with maturation.

Project STRIDE: Services for Transition to Independence through Education. Final Report, July 1988-June 1990 [and] Manual.

ERIC Educational Resources Information Center

Ross-Gordon, Jovita M.; And Others

The Services for Transition to Independence through Education (STRIDE) project evaluated a model for providing comprehensive training and employment services to adults with mild handicaps, using existing vocational education classes and special needs support programs in a secondary vocational technical school in Altoona, Pennsylvania. Services…

Greenwashing: Knowing Is Half the Battle

ERIC Educational Resources Information Center

Neugebauer, Adam

2011-01-01

The growing interest in "green" products in recent years has been met stride-for-stride with marketing campaigns attempting to tap into that trend. This once-niche sector was finally becoming mainstream and the market scrambled to meet that demand. Companies and organizations took steps to make themselves and their products and services more…

Can Democracy Represent Children? Toward a Politics of Difference

ERIC Educational Resources Information Center

Wall, John

2012-01-01

Children and youth under 18 have made significant strides in recent years toward fuller inclusion in democratic processes. These strides, however, rarely rise to the level of direct political representation, whether in changing policies, making laws, or voting. This article argues that democracies will be able to represent children only by…

Lower extremity muscle activation during baseball pitching.

PubMed

Campbell, Brian M; Stodden, David F; Nixon, Megan K

2010-04-01

The purpose of this study was to investigate muscle activation levels of select lower extremity muscles during the pitching motion. Bilateral surface electromyography data on 5 lower extremity muscles (biceps femoris, rectus femoris, gluteus maximus, vastus medialis, and gastrocnemius) were collected on 11 highly skilled baseball pitchers and compared with individual maximal voluntary isometric contraction (MVIC) data. The pitching motion was divided into 4 distinct phases: phase 1, initiation of pitching motion to maximum stride leg knee height; phase 2, maximum stride leg knee height to stride foot contact (SFC); phase 3, SFC to ball release; and phase 4, ball release to 0.5 seconds after ball release (follow-through). Results indicated that trail leg musculature elicited moderate to high activity levels during phases 2 and 3 (38-172% of MVIC). Muscle activity levels of the stride leg were moderate to high during phases 2-4 (23-170% of MVIC). These data indicate a high demand for lower extremity strength and endurance. Specifically, coaches should incorporate unilateral and bilateral lower extremity exercises for strength improvement or maintenance and to facilitate dynamic stabilization of the lower extremities during the pitching motion.

Analysis of walking variability through simultaneous evaluation of the head, lumbar, and lower-extremity acceleration in healthy youth

PubMed Central

Toda, Haruki; Nagano, Akinori; Luo, Zhiwei

2016-01-01

[Purpose] The purpose of this study was to clarify whether walking speed affects acceleration variability of the head, lumbar, and lower extremity by simultaneously evaluating of acceleration. [Subjects and Methods] Twenty young individuals recruited from among the staff at Kurashiki Heisei Hospital participated in this study. Eight accelerometers were used to measure the head, lumbar and lower extremity accelerations. The participants were instructed to walk at five walking speeds prescribed by a metronome. Acceleration variability was assessed by a cross-correlation analysis normalized using z-transform in order to evaluate stride-to-stride variability. [Results] Vertical acceleration variability was the smallest in all body parts, and walking speed effect had laterality. Antero-posterior acceleration variability was significantly associated with walking speed at sites other than the head. Medio-lateral acceleration variability of the bilateral hip alone was smaller than the antero-posterior variability. [Conclusion] The findings of this study suggest that the effect of walking speed changes on the stride-to-stride acceleration variability was individual for each body parts, and differs among directions. PMID:27390419

Three-dimensional kinematics of the pelvis and hind limbs in chimpanzee (Pan troglodytes) and human bipedal walking.

PubMed

O'Neill, Matthew C; Lee, Leng-Feng; Demes, Brigitte; Thompson, Nathan E; Larson, Susan G; Stern, Jack T; Umberger, Brian R

2015-09-01

The common chimpanzee (Pan troglodytes) is a facultative biped and our closest living relative. As such, the musculoskeletal anatomies of their pelvis and hind limbs have long provided a comparative context for studies of human and fossil hominin locomotion. Yet, how the chimpanzee pelvis and hind limb actually move during bipedal walking is still not well defined. Here, we describe the three-dimensional (3-D) kinematics of the pelvis, hip, knee and ankle during bipedal walking and compare those values to humans walking at the same dimensionless and dimensional velocities. The stride-to-stride and intraspecific variations in 3-D kinematics were calculated using the adjusted coefficient of multiple correlation. Our results indicate that humans walk with a more stable pelvis than chimpanzees, especially in tilt and rotation. Both species exhibit similar magnitudes of pelvis list, but with segment motion that is opposite in phasing. In the hind limb, chimpanzees walk with a more flexed and abducted limb posture, and substantially exceed humans in the magnitude of hip rotation during a stride. The average stride-to-stride variation in joint and segment motion was greater in chimpanzees than humans, while the intraspecific variation was similar on average. These results demonstrate substantial differences between human and chimpanzee bipedal walking, in both the sagittal and non-sagittal planes. These new 3-D kinematic data are fundamental to a comprehensive understanding of the mechanics, energetics and control of chimpanzee bipedalism. Copyright © 2015 Elsevier Ltd. All rights reserved.

Detecting Gait Asymmetry with Wearable Accelerometers

DTIC Science & Technology

2015-03-18

swing time to stride duration is referred to as swing factor [24]. Some features used in the past relate to the gait subphases: the heel - strike , when the...used in the past include the peaks of the impulse of the heel - strike [28] and toe-off force and the integral of the force over the course of the...with high acceleration and high jerk. Heel - strike and toe-off times are determined by extending outward from the identified stance time into areas of

Impact of stride-coupled gaze shifts of walking blowflies on the neuronal representation of visual targets

PubMed Central

Kress, Daniel; Egelhaaf, Martin

2014-01-01

During locomotion animals rely heavily on visual cues gained from the environment to guide their behavior. Examples are basic behaviors like collision avoidance or the approach to a goal. The saccadic gaze strategy of flying flies, which separates translational from rotational phases of locomotion, has been suggested to facilitate the extraction of environmental information, because only image flow evoked by translational self-motion contains relevant distance information about the surrounding world. In contrast to the translational phases of flight during which gaze direction is kept largely constant, walking flies experience continuous rotational image flow that is coupled to their stride-cycle. The consequences of these self-produced image shifts for the extraction of environmental information are still unclear. To assess the impact of stride-coupled image shifts on visual information processing, we performed electrophysiological recordings from the HSE cell, a motion sensitive wide-field neuron in the blowfly visual system. This cell has been concluded to play a key role in mediating optomotor behavior, self-motion estimation and spatial information processing. We used visual stimuli that were based on the visual input experienced by walking blowflies while approaching a black vertical bar. The response of HSE to these stimuli was dominated by periodic membrane potential fluctuations evoked by stride-coupled image shifts. Nevertheless, during the approach the cell’s response contained information about the bar and its background. The response components evoked by the bar were larger than the responses to its background, especially during the last phase of the approach. However, as revealed by targeted modifications of the visual input during walking, the extraction of distance information on the basis of HSE responses is much impaired by stride-coupled retinal image shifts. Possible mechanisms that may cope with these stride-coupled responses are discussed. PMID:25309362

Race and Gender Issues on the AP United States History Examination

ERIC Educational Resources Information Center

Venkateswaran, Uma

2004-01-01

Over the past two decades, remarkable strides have been made in examining, documenting, and incorporating race and gender issues in history courses, but it is time to take a look at the ways in which these curricular and pedagogical changes have impacted the Advanced Placement United States History Examination. This paper focuses on three…

Simplification May Not Be So Simple: Gauging State Alignment with the FAFSA

ERIC Educational Resources Information Center

Pingel, Sarah

2017-01-01

Applying for financial aid can be a complicated, time-consuming endeavor for students and their families. Fortunately, many state aid programs have taken strides to align aid applications to the form used for federal aid programs, the Free Application for Federal Student Aid (FAFSA), making state aid more readily accessible. New conversations…

''Can I Drop It This Time?'' Gender and Collaborative Group Dynamics in an Engineering Design-Based Afterschool Program

ERIC Educational Resources Information Center

Schnittka, Jessica; Schnittka, Christine

2016-01-01

The 21st century has brought an increasing demand for expertise in science, technology, engineering, and math (STEM). Although strides have been made towards increasing gender diversity in several of these disciplines, engineering remains primarily male dominated. In response, the U.S. educational system has attempted to make engineering…

Aquatic therapy for a child with type III spinal muscular atrophy: a case report.

PubMed

Salem, Yasser; Gropack, Stacy Jaffee

2010-11-01

Spinal muscular atrophy (SMA) is a neuromuscular disorder characterized by degeneration of alpha motor neurons. This case report describes an aquatic therapy program and the outcomes for a 3-year-old girl with type III SMA. Motor skills were examined using the 88-item Gross Motor Function Measure (GMFM), the Peabody Developmental Motor Scales (PDMS-2), and the GAITRite system. The child received aquatic therapy twice per week for 45-min sessions, for 14 weeks. The intervention included aquatic activities designed to improve gross motor skills and age-appropriate functional mobility. The GMFM total score improved by 11% following the intervention. The Standing Dimension score improved by 28% and the Walking, Running, and Jumping Dimension score improved by 18%. The gross motor quotient for the PDMS-2 improved from 66 to 74. The child's gait showed improvement in walking velocity, stride length, and single-limb support time as a percentage of the gait cycle. The outcomes of this case report demonstrate the successful improvement of gross motor function and gait in a 3-year-old child with SMA. This study provides clinical information for therapists utilizing aquatic therapy as a modality for children with neuromuscular disorders.

Effect of Horseback Riding Simulation Machine Training on Trunk Balance and Gait of Chronic Stroke Patients

PubMed Central

Kim, Hyungguen; Her, Jin Gang; Ko, Jooyeon

2014-01-01

[Purpose] The purpose of this study was to assess the effect of horseback riding simulation machine training on trunk balance and gait of patients with chronic stroke. [Subjects and Methods] The subjects were 20 patients hospitalized for treatment after being diagnosed with stroke. Horseback riding simulation training was provided for 30 minutes, 5 times a week, for 6 weeks. Trunk balance was assessed using the Trunk Impairment Scale (TIS) and a balance measuring device (Biorescue, RM ingenierie, France), and gait ability was measured using the Functional Gait Assessment (FGA) and a gait analyzer (GAITRite, CIR system Inc., USA). [Results] There were significant changes in movement area, distance and velocity of body sway as measured by the TIS and the balance measuring device, and in gait velocity, cadence, stride length and double limb support as measured by the FGA and gait analyzer. [Conclusion] Horseback riding simulation training improved the trunk balance and gait of chronic stroke patients. This present study provides preliminary objective data for future research, and useful clinical information for physical therapists using horseback riding simulation machines as a treatment modality for patients with chronic stroke. PMID:24567670

Individualization of music-based rhythmic auditory cueing in Parkinson's disease.

PubMed

Bella, Simone Dalla; Dotov, Dobromir; Bardy, Benoît; de Cock, Valérie Cochen

2018-06-04

Gait dysfunctions in Parkinson's disease can be partly relieved by rhythmic auditory cueing. This consists in asking patients to walk with a rhythmic auditory stimulus such as a metronome or music. The effect on gait is visible immediately in terms of increased speed and stride length. Moreover, training programs based on rhythmic cueing can have long-term benefits. The effect of rhythmic cueing, however, varies from one patient to the other. Patients' response to the stimulation may depend on rhythmic abilities, often deteriorating with the disease. Relatively spared abilities to track the beat favor a positive response to rhythmic cueing. On the other hand, most patients with poor rhythmic abilities either do not respond to the cues or experience gait worsening when walking with cues. An individualized approach to rhythmic auditory cueing with music is proposed to cope with this variability in patients' response. This approach calls for using assistive mobile technologies capable of delivering cues that adapt in real time to patients' gait kinematics, thus affording step synchronization to the beat. Individualized rhythmic cueing can provide a safe and cost-effective alternative to standard cueing that patients may want to use in their everyday lives. © 2018 New York Academy of Sciences.

Scale effects between body size and limb design in quadrupedal mammals.

PubMed

Kilbourne, Brandon M; Hoffman, Louwrens C

2013-01-01

Recently the metabolic cost of swinging the limbs has been found to be much greater than previously thought, raising the possibility that limb rotational inertia influences the energetics of locomotion. Larger mammals have a lower mass-specific cost of transport than smaller mammals. The scaling of the mass-specific cost of transport is partly explained by decreasing stride frequency with increasing body size; however, it is unknown if limb rotational inertia also influences the mass-specific cost of transport. Limb length and inertial properties--limb mass, center of mass (COM) position, moment of inertia, radius of gyration, and natural frequency--were measured in 44 species of terrestrial mammals, spanning eight taxonomic orders. Limb length increases disproportionately with body mass via positive allometry (length ∝ body mass(0.40)); the positive allometry of limb length may help explain the scaling of the metabolic cost of transport. When scaled against body mass, forelimb inertial properties, apart from mass, scale with positive allometry. Fore- and hindlimb mass scale according to geometric similarity (limb mass ∝ body mass(1.0)), as do the remaining hindlimb inertial properties. The positive allometry of limb length is largely the result of absolute differences in limb inertial properties between mammalian subgroups. Though likely detrimental to locomotor costs in large mammals, scale effects in limb inertial properties appear to be concomitant with scale effects in sensorimotor control and locomotor ability in terrestrial mammals. Across mammals, the forelimb's potential for angular acceleration scales according to geometric similarity, whereas the hindlimb's potential for angular acceleration scales with positive allometry.

Scale Effects between Body Size and Limb Design in Quadrupedal Mammals

PubMed Central

Kilbourne, Brandon M.; Hoffman, Louwrens C.

2013-01-01

Recently the metabolic cost of swinging the limbs has been found to be much greater than previously thought, raising the possibility that limb rotational inertia influences the energetics of locomotion. Larger mammals have a lower mass-specific cost of transport than smaller mammals. The scaling of the mass-specific cost of transport is partly explained by decreasing stride frequency with increasing body size; however, it is unknown if limb rotational inertia also influences the mass-specific cost of transport. Limb length and inertial properties – limb mass, center of mass (COM) position, moment of inertia, radius of gyration, and natural frequency – were measured in 44 species of terrestrial mammals, spanning eight taxonomic orders. Limb length increases disproportionately with body mass via positive allometry (length ∝ body mass0.40); the positive allometry of limb length may help explain the scaling of the metabolic cost of transport. When scaled against body mass, forelimb inertial properties, apart from mass, scale with positive allometry. Fore- and hindlimb mass scale according to geometric similarity (limb mass ∝ body mass1.0), as do the remaining hindlimb inertial properties. The positive allometry of limb length is largely the result of absolute differences in limb inertial properties between mammalian subgroups. Though likely detrimental to locomotor costs in large mammals, scale effects in limb inertial properties appear to be concomitant with scale effects in sensorimotor control and locomotor ability in terrestrial mammals. Across mammals, the forelimb's potential for angular acceleration scales according to geometric similarity, whereas the hindlimb's potential for angular acceleration scales with positive allometry. PMID:24260117

2D versus 3D in the kinematic analysis of the horse at the trot.

PubMed

Miró, F; Santos, R; Garrido-Castro, J L; Galisteo, A M; Medina-Carnicer, R

2009-08-01

The handled trot of three Lusitano Purebred stallions was analyzed by using 2D and 3D kinematical analysis methods. Using the same capture and analysis system, 2D and 3D data of some linear (stride length, maximal height of the hoof trajectories) and angular (angular range of motion, inclination of bone segments) variables were obtained. A paired Student T-test was performed in order to detect statistically significant differences between data resulting from the two methodologies With respect to the angular variables, there were significant differences in scapula inclination, shoulder angle, cannon inclination and protraction-retraction angle in the forelimb variables, but none of them were statistically different in the hind limb. Differences between the two methods were found in most of the linear variables analyzed.

Kick, Glide, Pole! Cross-Country Skiing Fun (Part II)

ERIC Educational Resources Information Center

Duoos, Bridget A.

2012-01-01

Part I of Kick, Glide, Pole! Cross-Country Skiing Fun, which was published in last issue, discussed how to select cross-country ski equipment, dress for the activity and the biomechanics of the diagonal stride. Part II focuses on teaching the diagonal stride technique and begins with a progression of indoor activities. Incorporating this fun,…

The effects of prolonged wear of textured shoe insoles on gait, foot sensation and proprioception in people with multiple sclerosis: study protocol for a randomised controlled trial.

PubMed

Hatton, Anna L; Dixon, John; Rome, Keith; Brauer, Sandra G; Williams, Katrina; Kerr, Graham

2016-04-21

Many people with multiple sclerosis experience problems with walking, which can make daily activities difficult and often leads to falls. Foot sensation plays an important role in keeping the body balanced whilst walking; however, people with multiple sclerosis often have poor sensation on the soles of their feet. Wearing a specially designed shoe insole, which enhances plantar sensory information, could help people with multiple sclerosis to walk better. This study will explore whether long-term wear of a textured insole can improve walking in people with multiple sclerosis. A prospective randomised controlled trial with two parallel groups will be conducted aiming to recruit 176 people with multiple sclerosis living in the community (Brisbane, Australia). Adults with a clinical diagnosis of multiple sclerosis, Disease Steps score 1-4, who are ambulant over 100 m and who meet specific inclusion criteria will be recruited. Participants will be randomised to a smooth control insole (n = 88) or textured insole (n = 88) group. The allocated insole will be worn for 12-weeks within participants' own footwear, with self-report wear diaries and falls calendars being completed over this period. Blinded assessors will conduct two baseline assessments and one post-intervention assessment. Gait tasks will be completed barefoot, wearing standardised footwear only, and wearing standardised footwear with smooth and textured insoles. The primary outcome measure will be mediolateral base of support when walking over even and uneven surfaces. Secondary measures include spatiotemporal gait parameters (stride length, stride time variability, double-limb support time, velocity), gait kinematics (hip, knee, and ankle joint angles, toe clearance, trunk inclination, arm swing, mediolateral pelvis/head displacement), foot sensation (light touch-pressure, vibration, two-point discrimination) and proprioception (ankle joint position sense). Group allocation will be concealed and all analyses will be based on an intention-to-treat principle. This study will explore the effects of wearing textured insoles over 12-weeks on gait, foot sensation and proprioception in people with multiple sclerosis. The study has the potential to identify a new, evidence-based footwear intervention which has the capacity to enhance mobility and independent living in people with multiple sclerosis. Australian New Zealand Clinical Trials Registry ACTRN12615000421538 . Registered 4 May 2015.