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Sample records for abnormal gait patterns

  1. Exercises to Improve Gait Abnormalities

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  2. Abnormal joint torque patterns exhibited by chronic stroke subjects while walking with a prescribed physiological gait pattern

    PubMed Central

    Neckel, Nathan D; Blonien, Natalie; Nichols, Diane; Hidler, Joseph

    2008-01-01

    leg, both being typical abnormal torque synergy patterns common to stroke gait. Conclusion Despite the Lokomat guiding stroke subjects through physiologically symmetric kinematic gait patterns, abnormal asymmetric joint torque patterns are still generated. These differences from the control group are characteristic of the hip hike and circumduction strategy employed by stroke subjects. PMID:18761735

  3. A gait paradigm reveals different patterns of abnormal cerebellar motor learning in primary focal dystonias.

    PubMed

    Hoffland, B S; Veugen, L C; Janssen, M M H P; Pasman, J W; Weerdesteyn, V; van de Warrenburg, B P

    2014-12-01

    Accumulating evidence points to a role of the cerebellum in the pathophysiology of primary dystonia. The aim of this study was to investigate whether the abnormalities of cerebellar motor learning in primary dystonia are solely detectable in more pure forms of cerebellum-dependent associative motor learning paradigms, or whether these are also present in other motor learning paradigms that rely heavily on the cerebellum but in addition require a more widespread sensorimotor network. Twenty-six patients with various forms of focal dystonia and 10 age-matched healthy controls participated in a motor learning paradigm on a split-belt treadmill. By using reflective markers, three-dimensional kinematics were recorded using a 6-camera motion analysis system. Adaptation walking parameters were analyzed offline, comparing the different dystonia groups and healthy controls. Patients with blepharospasm and writer's cramp were significantly impaired on various adaptation walking parameters. Whereas results of cervical dystonia patients did not differ from healthy controls in terms of adaptation walking parameters, differences in parameters of normal gait were found. We have here demonstrated abnormal sensorimotor adaptation with the split-belt paradigm in patients with blepharospasm and writer's cramp. This reinforces the current concept of cerebellar dysfunction in primary dystonia, and that this extends beyond more pure forms of cerebellum-dependent associative motor learning paradigms. However, the finding of normal adaptation in cervical dystonia patients indicates that the pattern of cerebellar dysfunction may be slightly different for the various forms of primary focal dystonia, suggesting that actual cerebellar pathology may not be a primary driving force in dystonia.

  4. Detection of abnormalities in a human gait using smart shoes

    NASA Astrophysics Data System (ADS)

    Kong, Kyoungchul; Bae, Joonbum; Tomizuka, Masayoshi

    2008-03-01

    Health monitoring systems require a means for detecting and quantifying abnormalities from measured signals. In this paper, a new method for detecting abnormalities in a human gait is proposed for an improved gait monitoring system for patients with walking problems. In the previous work, we introduced a fuzzy logic algorithm for detecting phases in a human gait based on four foot pressure sensors for each of the right and left foot. The fuzzy logic algorithm detects the gait phases smoothly and continuously, and retains all information obtained from sensors. In this paper, a higher level algorithm for detecting abnormalities in the gait phases obtained from the fuzzy logic is discussed. In the proposed algorithm, two major abnormalities are detected 1) when the sensors measure improper foot pressure patterns, and 2) when the human does not follow a natural sequence of gait phases. For mathematical realization of the algorithm, the gait phases are dealt with by a vector analysis method. The proposed detection algorithm is verified by experiments on abnormal gaits as well as normal gaits. The experiment makes use of the Smart Shoes that embeds four bladders filled with air, the pressure changes in which are detected by pressure transducers.

  5. Residual gait abnormalities in surgically treated spondylolisthesis.

    PubMed

    Shelokov, A; Haideri, N; Roach, J

    1993-11-01

    The authors retrospectively studied seven patients who had in situ fusion as adolescents for high-grade (IV, V) spondylolisthesis unresponsive to more conservative means. All patients achieved solid bony union; their pain was relieved; and hamstring spasm had resolved. The authors sought to determine whether crouch gait or any other abnormalities could be demonstrated in patients exhibiting clinical parameters of success. Each patient underwent gait analysis, radiographic analysis, and a physical examination. Four of seven patients demonstrated slight degrees of forward trunk lean during varying phases of gait accompanied by increased hip flexion. One patient demonstrated increased trunk extension accompanied by limited hip flexion. Two patients were essentially normal. The authors were unable to quantify residual crouch in these patients with solidly fused high-grade spondylolisthesis.

  6. Gait abnormalities, ADHD, and environmental exposure to nitrous oxide.

    PubMed

    Fluegge, Keith

    2016-08-30

    Papadopoulos et al. (2014) investigated gait profiles of children with attention-deficit hyperactivity disorder-combined type (ADHD-CT) compared to typical developing (TD) controls. The authors reported differences in the gait profile of ADHD-CT in the self-selected fast speed category. Additionally, others have proposed a maturational delay hypothesis in gait, demonstrating that gait variability decreases with age in ADHD children. It has been previously suggested that the cognitive impairment seen in conditions like ADHD may result from chronic, environmental exposure to the air pollutant, nitrous oxide (N2O). Exposure to N2O is thought to exert its antinociceptive properties by stimulating release of dynorphin peptides in the central nervous system which act upon kappa opioid receptors (KOR). Opioid-mediated gait abnormalities in ADHD are supported with evidence that prodynorphin mutations in mice lead to cytotoxic levels of dynorphin A (DYN A) and contribute to abnormal gait profiles and gradual loss of motor coordination. Interestingly, constitutive activity of the KOR receptor in rat brain has been recently shown to undergo maturational alterations, suggesting that while altered gait profiles in ADHD may be a function of the enhanced opioidergic activity attributable to chronic exposure to the environmental air pollutant, N2O, age-attenuated constitutive activity of KOR in brain may explain the normalization of these altered gait profiles in older ADHD subjects. PMID:27285951

  7. Perception of gait patterns that deviate from normal and symmetric biped locomotion

    PubMed Central

    Handžić, Ismet; Reed, Kyle B.

    2015-01-01

    This study examines the range of gait patterns that are perceived as healthy and human-like with the goal of understanding how much asymmetry is allowable in a gait pattern before other people start to notice a gait impairment. Specifically, this study explores if certain abnormal walking patterns can be dismissed as unimpaired or not uncanny. Altering gait biomechanics is generally done in the fields of prosthetics and rehabilitation, however the perception of gait is often neglected. Although a certain gait can be functional, it may not be considered as normal by observers. On the other hand, an abnormally perceived gait may be more practical or necessary in some situations, such as limping after an injury or stroke and when wearing a prosthesis. This research will help to find the balance between the form and function of gait. Gait patterns are synthetically created using a passive dynamic walker (PDW) model that allows gait patterns to be systematically changed without the confounding influence from human sensorimotor feedback during walking. This standardized method allows the perception of specific changes in gait to be studied. The PDW model was used to produce walking patterns that showed a degree of abnormality in gait cadence, knee height, step length, and swing time created by changing the foot roll-over-shape, knee damping, knee location, and leg masses. The gait patterns were shown to participants who rated them according to separate scales of impairment and uncanniness. The results indicate that some pathological and asymmetric gait patterns are perceived as unimpaired and normal. Step time and step length asymmetries less than 5%, small knee location differences, and gait cadence changes of 25% do not result in a change in perception. The results also show that the parameters of a pathologically or uncanny perceived gait can be beneficially altered by increasing other independent parameters, in some sense masking the initial pathology. PMID:25774144

  8. Gait pattern differences between children with mild scoliosis and children with unilateral cerebral palsy.

    PubMed

    Domagalska-Szopa, Małgorzata; Szopa, Andrzej

    2014-01-01

    This study was conducted to investigate the effects of asymmetrical body posture alone, i.e., the effects seen in children with mild scoliosis, vs. the effects of body posture control impairment, i.e., those seen in children with unilateral cerebral palsy on gait patterns. Three-dimensional instrumented gait analysis (3DGA) was conducted in 45 children with hemiplegia and 51 children with mild scoliosis. All the children were able to walk without assistance devices. A set of 35 selected spatiotemporal gait and kinematics parameters were evaluated when subjects walked on a treadmill. A cluster analysis revealed 3 different gait patterns: a scoliotic gait pattern and 2 different hemiplegic gait patterns. The results showed that the discrepancy in gait patterns was not simply a lower limb kinematic deviation in the sagittal plane, as expected. Additional altered kinematics, such as pelvic misorientation in the coronal plane in both the stance and swing phases and inadequate stance phase hip ad/abduction, which resulted from postural pattern features, were distinguished between the 3 gait patterns. Our study provides evidence for a strong correlation between postural and gait patterns in children with unilateral cerebral palsy. Information on differences in gait patterns may be used to improve the guidelines for early therapy for children with hemiplegia before abnormal gait patterns are fully established. The gait pathology characteristic of scoliotic children is a potential new direction for treating scoliosis that complements the standard posture and walking control therapy exercises with the use of biofeedback.

  9. Gait pattern differences between children with mild scoliosis and children with unilateral cerebral palsy.

    PubMed

    Domagalska-Szopa, Małgorzata; Szopa, Andrzej

    2014-01-01

    This study was conducted to investigate the effects of asymmetrical body posture alone, i.e., the effects seen in children with mild scoliosis, vs. the effects of body posture control impairment, i.e., those seen in children with unilateral cerebral palsy on gait patterns. Three-dimensional instrumented gait analysis (3DGA) was conducted in 45 children with hemiplegia and 51 children with mild scoliosis. All the children were able to walk without assistance devices. A set of 35 selected spatiotemporal gait and kinematics parameters were evaluated when subjects walked on a treadmill. A cluster analysis revealed 3 different gait patterns: a scoliotic gait pattern and 2 different hemiplegic gait patterns. The results showed that the discrepancy in gait patterns was not simply a lower limb kinematic deviation in the sagittal plane, as expected. Additional altered kinematics, such as pelvic misorientation in the coronal plane in both the stance and swing phases and inadequate stance phase hip ad/abduction, which resulted from postural pattern features, were distinguished between the 3 gait patterns. Our study provides evidence for a strong correlation between postural and gait patterns in children with unilateral cerebral palsy. Information on differences in gait patterns may be used to improve the guidelines for early therapy for children with hemiplegia before abnormal gait patterns are fully established. The gait pathology characteristic of scoliotic children is a potential new direction for treating scoliosis that complements the standard posture and walking control therapy exercises with the use of biofeedback. PMID:25089908

  10. A computational method for reliable gait event detection and abnormality detection for feedback in rehabilitation.

    PubMed

    Senanayake, Chathuri; Senanayake, S M N Arosha

    2011-10-01

    In this paper, a gait event detection algorithm is presented that uses computer intelligence (fuzzy logic) to identify seven gait phases in walking gait. Two inertial measurement units and four force-sensitive resistors were used to obtain knee angle and foot pressure patterns, respectively. Fuzzy logic is used to address the complexity in distinguishing gait phases based on discrete events. A novel application of the seven-dimensional vector analysis method to estimate the amount of abnormalities detected was also investigated based on the two gait parameters. Experiments were carried out to validate the application of the two proposed algorithms to provide accurate feedback in rehabilitation. The algorithm responses were tested for two cases, normal and abnormal gait. The large amount of data required for reliable gait-phase detection necessitate the utilisation of computer methods to store and manage the data. Therefore, a database management system and an interactive graphical user interface were developed for the utilisation of the overall system in a clinical environment.

  11. Longitudinal assessment of gait abnormalities following penetrating ballistic-like brain injury in rats.

    PubMed

    Mountney, Andrea; Leung, Lai Yee; Pedersen, Rebecca; Shear, Deborah; Tortella, Frank

    2013-01-15

    Traumatic brain injury (TBI) results in enduring motor and cognitive dysfunction. Although gait disturbances have been documented among TBI patients, few studies have profiled gait abnormalities in animal models of TBI. We sought to obtain a comprehensive longitudinal analysis of gait function following severe penetrating ballistic-like brain injury (PBBI) in rats. Rats were subjected to either unilateral frontal PBBI, probe insertion alone, or sham surgery. Sensorimotor performance was assessed using the CatWalk automated gait analysis system. Baseline measurements were taken 3 days prior to injury and detailed analysis of gait was performed at 1, 3, 7, 14, and 28 days post-injury. Both PBBI and probe-inserted rats displayed altered static and dynamic gait parameters that were primarily evident during the early (<7 days) post-injury phase and were resolved by 1 month post-injury. PBBI produced more severe deficits compared to probe-alone which were reflected in the number, magnitude, and resolution time of abnormal gait parameters. While altered parameters were detected in all four paws, they were more apparent on the contralateral side. Gait parameters including paw pressure, print area, swing speed, and stride length were significantly decreased whereas stance, swing, and step cycle duration were increased compared to sham. Overall, altered gait patterns detected using the CatWalk system in the PBBI model were injury-severity dependent, resolved at later time points, and appeared similar to those reported in severe TBI patients. These results indicate that the CatWalk may be most useful for neuroprotection studies that focus on the acute/subacute recovery period after TBI.

  12. Gait pattern in the early recovery period after stroke.

    PubMed

    De Quervain, I A; Simon, S R; Leurgans, S; Pease, W S; McAllister, D

    1996-10-01

    The gait patterns of eighteen patients who had had a single infarct due to obstruction of the middle cerebral artery were evaluated within one week after the patients had resumed independent walking and before a gait rehabilitation program had been initiated. Gait was analyzed with use of motion analysis, force-plate recordings, and dynamic surface electromyographic studies of the muscles of the lower extremities. The patterns of motion of the lower extremity on the hemiplegic side had a stronger association with the clinical severity of muscle weakness than with the degree of spasticity, balance control, or phasic muscle activity. There was a delay in the initiation of flexion of the hip during the pre-swing phase, and flexion of the hip and knee as well as dorsiflexion of the ankle progressed only slightly during the swing phase. During the stance phase, there was decreased extension of the hip that was related to decreased muscle effort and a coupling between flexion of the knee and dorsiflexion of the ankle. The abnormal patterns of motion altered the velocity, the length of the stride, the cadence, and all phases of the gait cycle. The duration of the pre-swing phase was prolonged for the patients who had the slowest gait velocities. There also were abnormal movements of the upper extremity, the trunk, the pelvis, and the lower extremity on the unaffected side in an effort to compensate for the decreased velocity on the hemiplegic side. As velocity improved, these abnormal movements decreased. Therefore, the goal of therapy should be to improve muscle strength and coordination on the hemiplegic side, especially during the pre-swing phase.

  13. Kinematic analysis quantifies gait abnormalities associated with lameness in broiler chickens and identifies evolutionary gait differences.

    PubMed

    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

  14. Predisability and gait patterns in older adults.

    PubMed

    Verghese, Joe; Xue, Xiaonan

    2011-01-01

    Presence of performance inconsistency during repeated assessments of gait may reflect underlying subclinical disease, and help shed light on the earliest stages of disablement. We studied inter-session fluctuations on three selected gait measures (velocity, stride length, and stride length variability) during normal pace walking as well as during a cognitively demanding 'walking while talking' condition using a repeated measurement burst design (six sessions within a 2-week period) in 71 nondisabled and nondemented community residing older adults, 40 with predisability (does activities of daily living unassisted but with difficulty). Subjects with predisability had slower gait velocity and shorter stride length on both the normal and walking while talking conditions at baseline compared to nondisabled subjects. However, there was no significant pattern of fluctuations across the six sessions on the three selected gait variables comparing the two groups during normal walking as well as on the walking while talking conditions. Our findings support consistency of gait measurements during the earliest stages of disability.

  15. Gait patterns after anterior cruciate ligament reconstruction.

    PubMed

    Bulgheroni, P; Bulgheroni, M V; Andrini, L; Guffanti, P; Giughello, A

    1997-01-01

    The aim of this study is to analyse the changes in select gait parameters following anterior cruciate ligament (ACL) reconstruction. The study was performed on 15 subjects who underwent ACL reconstruction by the bone-patellar tendon-bone technique. Gait analysis was performed using the Elite three-dimensional (3D) optoelectronic system (BTS), a Kistler force platform and the Telemg telemetric electromyograph (BTS). Kinematic data were recorded for the principal lower limb joints (hip, knee and ankle). The examined muscles include vastus lateralis, rectus femoris, biceps femoris and semitendinosus. The results obtained from the operated subjects were compared with those of 10 untreated subjects and 5 subjects without ACL damage. In the operated subjects the knee joint angular values regained a normal flexion pattern for the injured limb during the stance phase. The analysis of joint moments shows: (a) sagittal plane: recovery of the knee flexion moment at loading response and during preswing; (b) frontal plane: recovery of the normal patterns for both hip and knee adduction-abduction moments during the entire stance phase. The examination of ground reaction forces reveals the recovery of frontal component features. The EMG traces show the normal biphasic pattern for the operated subjects as compared to the untreated subjects. The results suggest that the gait parameters shift towards normal value patterns.

  16. Gait patterns for crime fighting: statistical evaluation

    NASA Astrophysics Data System (ADS)

    Sulovská, Kateřina; Bělašková, Silvie; Adámek, Milan

    2013-10-01

    The criminality is omnipresent during the human history. Modern technology brings novel opportunities for identification of a perpetrator. One of these opportunities is an analysis of video recordings, which may be taken during the crime itself or before/after the crime. The video analysis can be classed as identification analyses, respectively identification of a person via externals. The bipedal locomotion focuses on human movement on the basis of their anatomical-physiological features. Nowadays, the human gait is tested by many laboratories to learn whether the identification via bipedal locomotion is possible or not. The aim of our study is to use 2D components out of 3D data from the VICON Mocap system for deep statistical analyses. This paper introduces recent results of a fundamental study focused on various gait patterns during different conditions. The study contains data from 12 participants. Curves obtained from these measurements were sorted, averaged and statistically tested to estimate the stability and distinctiveness of this biometrics. Results show satisfactory distinctness of some chosen points, while some do not embody significant difference. However, results presented in this paper are of initial phase of further deeper and more exacting analyses of gait patterns under different conditions.

  17. Modification of hemiplegic compensatory gait pattern by symmetry-based motion controller of HAL.

    PubMed

    Kawamoto, Hiroaki; Kadone, Hideki; Sakurai, Takeru; Sankai, Yoshiyuki

    2015-01-01

    As one of several characteristics of hemiplegic patients after stroke, compensatory gait caused by affected limb is often seen. The purpose of this research is to apply a symmetry-based controller of a wearable type lower limb robot, Hybrid Assistive Limb (HAL) to hemiplegic patients with compensatory gait, and to investigate improvement of gait symmetry. The controller is designed respectively for swing phase and support phase according to characteristics of hemiplegic gait pattern. The controller during swing phase stores the motion of the unaffected limb and then provides motion support on the affected limb during the subsequent swing using the stored pattern to realize symmetric gait based on spontaneous limb swing. Moreover, the controller during support phase provides motion to extend hip and knee joints to support wearer's body. Clinical tests were conducted in order to assess the modification of gait symmetry. Our case study involved participation of one chronic stroke patient who performs abnormally-compensatory gait for both of the affected and unaffected limbs. As a result, the patient's gait symmetry was improved by providing motion support during the swing phase on the affected side and motion constraint during the support phase on the unaffected side. The study showed promising basis for the effectiveness of the controller for the future clinical study.

  18. Intra-individual gait pattern variability in specific situations: Implications for forensic gait analysis.

    PubMed

    Ludwig, Oliver; Dillinger, Steffen; Marschall, Franz

    2016-07-01

    In this study, inter- and intra-individual gait pattern differences are examined in various gait situations by means of phase diagrams of the extremity angles (cyclograms). 8 test subjects walked along a walking distance of 6m under different conditions three times each: barefoot, wearing sneakers, wearing combat boots, after muscular fatigue, and wearing a full-face motorcycle helmet restricting vision. The joint angles of foot, knee, and hip were recorded in the sagittal plane. The coupling of movements was represented by time-adjusted cyclograms, and the inter- and intra-individual differences were captured by calculating the similarity between different gait patterns. Gait pattern variability was often greater between the defined test situations than between the individual test subjects. The results have been interpreted considering neurophysiological regulation mechanisms. Footwear, masking, and fatigue were interpreted as disturbance parameters, each being a cause for gait pattern variability and complicating the inference of identity of persons in video recordings.

  19. Intra-individual gait pattern variability in specific situations: Implications for forensic gait analysis.

    PubMed

    Ludwig, Oliver; Dillinger, Steffen; Marschall, Franz

    2016-07-01

    In this study, inter- and intra-individual gait pattern differences are examined in various gait situations by means of phase diagrams of the extremity angles (cyclograms). 8 test subjects walked along a walking distance of 6m under different conditions three times each: barefoot, wearing sneakers, wearing combat boots, after muscular fatigue, and wearing a full-face motorcycle helmet restricting vision. The joint angles of foot, knee, and hip were recorded in the sagittal plane. The coupling of movements was represented by time-adjusted cyclograms, and the inter- and intra-individual differences were captured by calculating the similarity between different gait patterns. Gait pattern variability was often greater between the defined test situations than between the individual test subjects. The results have been interpreted considering neurophysiological regulation mechanisms. Footwear, masking, and fatigue were interpreted as disturbance parameters, each being a cause for gait pattern variability and complicating the inference of identity of persons in video recordings. PMID:26990706

  20. Characterization of gait pattern by 3D angular accelerations in hemiparetic and healthy gait.

    PubMed

    Rueterbories, Jan; Spaich, Erika G; Andersen, Ole K

    2013-02-01

    Characterization of gait pattern is of interest for clinical gait assessment. Past developments of ambulatory measurement systems have still limitations for daily usage in the clinical environment. This study investigated the potential of 3D angular accelerations of foot, shank, and thigh to characterize gait events and phases of ten healthy and ten hemiparetic subjects. The key feature of the system was the use of angular accelerations obtained by differential measurement. Further, the effect of sensor position and walking cadence on the signal was investigated. We found that gait phases are characterized as modulated amplitudes of angular accelerations of foot, shank, and thigh. Increasing the gait cadence from 70 steps/min to 100 steps/min caused an amplitude increase of the magnitude of the vector, summing all 3D angular accelerations on the sensor position (p<0.001). Comparison of healthy and hemiparetic gait showed a lower mean of the magnitude of the vector during the loading response in the hemiparetic gait (p<0.05), while during pre-swing and swing no significant differences between healthy and hemiparetic gait were observed. A comparison of the tangential acceleration component in the frontal plane showed no statistically significant difference between healthy and hemiparetic gait. Further, no statistically significant difference between the tangential components was found for both groups. This method demonstrated promising results for a possible use for gait assessment.

  1. Hindlimb lameness and gait abnormalities in bitches with pyometra.

    PubMed

    Klainbart, S; Ranen, E; Glikman, G; Kelmer, E; Bdolah-Abram, T; Aroch, I

    2014-07-12

    The objective of this study was to assess the frequency of gait abnormalities and lameness (GAL) in bitches with pyometra, and their association with clinical and laboratory findings. The study included 79 bitches diagnosed with pyometra and 35 negative control intact bitches presented with other soft tissue surgical disorders. Dogs with a history of chronic lameness due to orthopaedic or neurological origin were excluded. A history of GAL was more frequent in the pyometra group (47 per cent) compared with the control group (20 per cent) (P=0.007). In the pyometra group, bitches presenting GAL had (P<0.04) higher frequencies of closed-cervix pyometra, anorexia and vomiting, as well as higher serum creatinine concentration and muscle enzymes activity, compared with those in without GAL. GAL signs resolved postovariohysterectomy in all but one bitch. The results suggest that GAL signs occur frequently in bitches with pyometra, especially in closed-cervix disease. Therefore, pyometra should be considered among the differential diagnoses when GAL occurs, especially when the clinical signs are non-specific and the reproductive history is unclear. PMID:24789856

  2. Complex patterns of abnormal heartbeats

    NASA Technical Reports Server (NTRS)

    Schulte-Frohlinde, Verena; Ashkenazy, Yosef; Goldberger, Ary L.; Ivanov, Plamen Ch; Costa, Madalena; Morley-Davies, Adrian; Stanley, H. Eugene; Glass, Leon

    2002-01-01

    Individuals having frequent abnormal heartbeats interspersed with normal heartbeats may be at an increased risk of sudden cardiac death. However, mechanistic understanding of such cardiac arrhythmias is limited. We present a visual and qualitative method to display statistical properties of abnormal heartbeats. We introduce dynamical "heartprints" which reveal characteristic patterns in long clinical records encompassing approximately 10(5) heartbeats and may provide information about underlying mechanisms. We test if these dynamics can be reproduced by model simulations in which abnormal heartbeats are generated (i) randomly, (ii) at a fixed time interval following a preceding normal heartbeat, or (iii) by an independent oscillator that may or may not interact with the normal heartbeat. We compare the results of these three models and test their limitations to comprehensively simulate the statistical features of selected clinical records. This work introduces methods that can be used to test mathematical models of arrhythmogenesis and to develop a new understanding of underlying electrophysiologic mechanisms of cardiac arrhythmia.

  3. Sagittal gait patterns in cerebral palsy: the plantarflexor-knee extension couple index.

    PubMed

    Sangeux, Morgan; Rodda, Jill; Graham, H Kerr

    2015-02-01

    The identification of gait patterns in cerebral palsy offers a common language for clinicians and contributes to management algorithms. We describe a quantitative classification of sagittal gait patterns based on the plantarflexor-knee extension couple index. This consists of a scatter plot based on ankle and knee scores, and allows objective identification of the sagittal gait pattern. Sagittal kinematic data from 200 limbs of 100 patients with bilateral spastic cerebral palsy were utilized to validate the algorithm against the assessment of a clinician with expertise in gait pattern identification. A dataset of 776 cerebral palsy patients, 1552 limbs, was used to compare the sagittal gait patterns against k-means statistical clustering. The classification was further explored with respect to the knee kinetics during the middle of stance and physical examination measurements of the gastrocnemius-soleus complex. Two supplementary materials (Appendices 2 and 3) provide in-depth discussion about statistical properties of the plantarflexor-knee extension couple index as well as its relationship with statistical clustering. The plantarflexor-knee extension index achieved 98% accuracy and may be suitable for the computational classification of large patient cohorts and multicentre studies. The sagittal gait patterns were strongly related to k-means statistical clustering and physical examination of the gastrocnemius-soleus complex. Patients in crouch gait had normal soleus and gastrocnemius lengths but spasticity in the gastrocnemius. Patients in jump gait exhibited a short gastrocnemius and soleus and gastrocnemius spasticity. Patients in true equinus presented with a moderately contracted soleus and gastrocnemius and gastrocnemius spasticity. Patients in apparent equinus did not show abnormal physical examination measurements for the gastrocnemius-soleus complex.

  4. 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.

  5. Gait patterns in COPD: the Rotterdam Study.

    PubMed

    Lahousse, Lies; Verlinden, Vincentius J A; van der Geest, Jos N; Joos, Guy F; Hofman, Albert; Stricker, Bruno H C; Brusselle, Guy G; Ikram, M Arfan

    2015-07-01

    Gait disturbances in patients with chronic obstructive pulmonary disease (COPD) may lead to disability and falls. As studies assessing gait kinematics in COPD are sparse, we investigated associations of COPD with various gait domains and explored a potential link with falling. Gait was measured within the prospective, population-based Rotterdam Study (age ≥55 years) using an electronic walkway and summarised into seven gait domains: Rhythm, Variability, Phases, Pace, Tandem, Turning and Base of Support. Rhythm is a temporal gait aspect that includes cadence and reflects how quickly steps are taken. Persons with COPD (n=196) exhibited worse Rhythm (-0.21 SD, 95% CI -0.36- -0.06 SD) compared with persons with normal lung function (n=898), independent of age, sex, height, education, smoking or analgesic use, especially when dyspnoea and severe airflow limitation or frequent exacerbations (Global Initiative for Chronic Obstructive Lung Disease group D: -0.83 SD, 95% CI -1.25- -0.41 SD) were present. A lower forced expiratory volume in 1 s was associated with worse Rhythm and Pace, including lower cadence and gait velocity, respectively. Importantly, fallers with COPD had significantly worse Rhythm than nonfallers with COPD. This study demonstrates that persons with COPD exhibit worse Rhythm, especially fallers with COPD. The degree of Rhythm deterioration was associated with the degree of airflow limitation, symptoms and frequency of exacerbations.

  6. Kinematic gait patterns in healthy runners: A hierarchical cluster analysis.

    PubMed

    Phinyomark, Angkoon; Osis, Sean; Hettinga, Blayne A; Ferber, Reed

    2015-11-01

    Previous studies have demonstrated distinct clusters of gait patterns in both healthy and pathological groups, suggesting that different movement strategies may be represented. However, these studies have used discrete time point variables and usually focused on only one specific joint and plane of motion. Therefore, the first purpose of this study was to determine if running gait patterns for healthy subjects could be classified into homogeneous subgroups using three-dimensional kinematic data from the ankle, knee, and hip joints. The second purpose was to identify differences in joint kinematics between these groups. The third purpose was to investigate the practical implications of clustering healthy subjects by comparing these kinematics with runners experiencing patellofemoral pain (PFP). A principal component analysis (PCA) was used to reduce the dimensionality of the entire gait waveform data and then a hierarchical cluster analysis (HCA) determined group sets of similar gait patterns and homogeneous clusters. The results show two distinct running gait patterns were found with the main between-group differences occurring in frontal and sagittal plane knee angles (P<0.001), independent of age, height, weight, and running speed. When these two groups were compared to PFP runners, one cluster exhibited greater while the other exhibited reduced peak knee abduction angles (P<0.05). The variability observed in running patterns across this sample could be the result of different gait strategies. These results suggest care must be taken when selecting samples of subjects in order to investigate the pathomechanics of injured runners.

  7. Symmetry in locomotor central pattern generators and animal gaits

    NASA Astrophysics Data System (ADS)

    Golubitsky, Martin; Stewart, Ian; Buono, Pietro-Luciano; Collins, J. J.

    1999-10-01

    Animal locomotion is controlled, in part, by a central pattern generator (CPG), which is an intraspinal network of neurons capable of generating a rhythmic output. The spatio-temporal symmetries of the quadrupedal gaits walk, trot and pace lead to plausible assumptions about the symmetries of locomotor CPGs. These assumptions imply that the CPG of a quadruped should consist of eight nominally identical subcircuits, arranged in an essentially unique matter. Here we apply analogous arguments to myriapod CPGs. Analyses based on symmetry applied to these networks lead to testable predictions, including a distinction between primary and secondary gaits, the existence of a new primary gait called `jump', and the occurrence of half-integer wave numbers in myriapod gaits. For bipeds, our analysis also predicts two gaits with the out-of-phase symmetry of the walk and two gaits with the in-phase symmetry of the hop. We present data that support each of these predictions. This work suggests that symmetry can be used to infer a plausible class of CPG network architectures from observed patterns of animal gaits.

  8. Wavelet-based characterization of gait signal for neurological abnormalities.

    PubMed

    Baratin, E; Sugavaneswaran, L; Umapathy, K; Ioana, C; Krishnan, S

    2015-02-01

    Studies conducted by the World Health Organization (WHO) indicate that over one billion suffer from neurological disorders worldwide, and lack of efficient diagnosis procedures affects their therapeutic interventions. Characterizing certain pathologies of motor control for facilitating their diagnosis can be useful in quantitatively monitoring disease progression and efficient treatment planning. As a suitable directive, we introduce a wavelet-based scheme for effective characterization of gait associated with certain neurological disorders. In addition, since the data were recorded from a dynamic process, this work also investigates the need for gait signal re-sampling prior to identification of signal markers in the presence of pathologies. To benefit automated discrimination of gait data, certain characteristic features are extracted from the wavelet-transformed signals. The performance of the proposed approach was evaluated using a database consisting of 15 Parkinson's disease (PD), 20 Huntington's disease (HD), 13 Amyotrophic lateral sclerosis (ALS) and 16 healthy control subjects, and an average classification accuracy of 85% is achieved using an unbiased cross-validation strategy. The obtained results demonstrate the potential of the proposed methodology for computer-aided diagnosis and automatic characterization of certain neurological disorders. PMID:25661004

  9. Implementing gait pattern control and transition for legged locomotion

    NASA Astrophysics Data System (ADS)

    Yang, Zhijun; Rocha, Marlon V.; Lima, Priscila M. V.; Karamanoglu, Mehmet; França, Felipe M. G.

    2014-07-01

    In this work, a generalised central pattern generator (CPG) model is formulated to generate a full range of gait patterns for a hexapod insect. To this end, a recurrent neuronal network module, as the building block for rhythmic patterns, is proposed to extend the concept of oscillatory building blocks (OBB) for constructing a CPG model. The model is able to make transitions between different gait patterns by simply adjusting one model parameter. Simulation results are further presented to show the effectiveness and performance of the CPG network.

  10. Recovery of gait pattern after medial patellofemoral ligament reconstruction for objective patellar instability.

    PubMed

    Carnesecchi, O; Philippot, R; Boyer, B; Farizon, F; Edouard, P

    2016-01-01

    Gait pattern alterations were previously reported in association with objective patellar instability (OPI). Gait pattern comparison between a series of patients having undergone medial patellofemoral ligament (MPFL) reconstruction and a sample of control subjects. Thirty patients at 6 months postoperatively after MPFL reconstruction and thirty control subjects were enrolled in the study for a clinical and biomechanical assessment including gait analysis at three selected walking rates using the GAITRite(®) system. The mean raw IKDC score was 73 (± 19), and the mean Kujala knee function was 84 (± 17.5). The study of gait did not demonstrate any significant difference between the two groups at a normal and fast walking rate. At a 10 km/h running speed, the single-support phase was significantly shortened by a mean 2.33% (p < 0.05), the swing phase by a mean 2.64% (p < 0.05) and the double-support phase by a mean 3.49% (p < 0.05) on the operated side. MPFL reconstruction reported good midterm functional and clinical results in the management of OPI. At 6 months postoperatively, the patient gait pattern was similar to that observed in healthy subjects at a normal and fast walking speed. However, our study revealed persistent gait abnormalities at a 10 km/h running speed. These gait alterations seemed to be related to the ligament reconstruction in itself due to the higher strain applied on the reconstructed MPFL during running cycle (10 km/h). Level of evidence IV.

  11. Gait Patterns in Patients with Hereditary Spastic Paraparesis

    PubMed Central

    Ranavolo, Alberto; Lacquaniti, Francesco; Martino, Giovanni; Leonardi, Luca; Conte, Carmela; Varrecchia, Tiwana; Draicchio, Francesco; Coppola, Gianluca; Casali, Carlo; Pierelli, Francesco

    2016-01-01

    Background Spastic gait is a key feature in patients with hereditary spastic paraparesis, but the gait characterization and the relationship between the gait impairment and clinical characteristics have not been investigated. Objectives To describe the gait patterns in hereditary spastic paraparesis and to identify subgroups of patients according to specific kinematic features of walking. Methods We evaluated fifty patients by computerized gait analysis and compared them to healthy participants. We computed time-distance parameters of walking and the range of angular motion at hip, knee, and ankle joints, and at the trunk and pelvis. Lower limb joint moments and muscle co-activation values were also evaluated. Results We identified three distinct subgroups of patients based on the range of motion values. Subgroup one was characterized by reduced hip, knee, and ankle joint range of motion. These patients were the most severely affected from a clinical standpoint, had the highest spasticity, and walked at the slowest speed. Subgroup three was characterized by an increased hip joint range of motion, but knee and ankle joint range of motion values close to control values. These patients were the most mildly affected and had the highest walking speed. Finally, subgroup two showed reduced knee and ankle joint range of motion, and hip range of motion values close to control values. Disease severity and gait speed in subgroup two were between those of subgroups one and three. Conclusions We identified three distinctive gait patterns in patients with hereditary spastic paraparesis that correlated robustly with clinical data. Distinguishing specific features in the gait patterns of these patients may help tailor pharmacological and rehabilitative treatments and may help evaluate therapeutic effects over time. PMID:27732632

  12. Assistive devices alter gait patterns in Parkinson disease: advantages of the four-wheeled walker.

    PubMed

    Kegelmeyer, Deb A; Parthasarathy, Sowmya; Kostyk, Sandra K; White, Susan E; Kloos, Anne D

    2013-05-01

    Gait abnormalities are a hallmark of Parkinson's disease (PD) and contribute to fall risk. Therapy and exercise are often encouraged to increase mobility and decrease falls. As disease symptoms progress, assistive devices are often prescribed. There are no guidelines for choosing appropriate ambulatory devices. This unique study systematically examined the impact of a broad range of assistive devices on gait measures during walking in both a straight path and around obstacles in individuals with PD. Quantitative gait measures, including velocity, stride length, percent swing and double support time, and coefficients of variation were assessed in 27 individuals with PD with or without one of six different devices including canes, standard and wheeled walkers (two, four or U-Step). Data were collected using the GAITRite and on a figure-of-eight course. All devices, with the exception of four-wheeled and U-Step walkers significantly decreased gait velocity. The four-wheeled walker resulted in less variability in gait measures and had less impact on spontaneous unassisted gait patterns. The U-Step walker exhibited the highest variability across all parameters followed by the two-wheeled and standard walkers. Higher variability has been correlated with increased falls. Though subjects performed better on a figure-of-eight course using either the four-wheeled or the U-Step walker, the four-wheeled walker resulted in the most consistent improvement in overall gait variables. Laser light use on a U-Step walker did not improve gait measures or safety in figure-of-eight compared to other devices. Of the devices tested, the four-wheeled-walker offered the most consistent advantages for improving mobility and safety.

  13. Gait patterns before and after anterior cruciate ligament reconstruction.

    PubMed

    Knoll, Zsolt; Kocsis, László; Kiss, Rita M

    2004-01-01

    The aim of this study is to determine how selected gait parameters may change as a result of anterior cruciate ligament (ACL) deficiency and following ACL reconstruction. The study was performed on 25 ACL-deficient subjects prior to and 6 weeks, 4 months, 8 months and 12 months after ACL reconstructive surgery by the bone-patellar tendon-bone technique. Gait analysis was performed using the zebris three-dimensional ultrasound-based system with surface electromyograph (zebris Medizintechnik GmbH, Germany). Kinematic data were recorded for the lower limb. The muscles examined include vastus lateralis and medialis, biceps femoris and adductor longus. The results obtained from the injured subjects were compared with those of 51 individuals without ACL damage. The acute ACL-deficient patients exhibited a quadriceps avoidance pattern prior to and 6 weeks after surgery. The quadriceps avoidance phenomenon does not develop in chronic ACL-deficient patients. In the individuals operated on, the spatial-temporal parameters and the knee angle had already regained a normal pattern for the ACL-deficient limb during gait 4 months after surgery. However, the relative ACL movement parameter-which describes the tibial translation into the direction of ACL-and the EMG traces show no significant statistical difference compared with the values of healthy control group just 8 months after surgery. The results suggest that: (1) development of a quadriceps avoidance pattern is less common than previously reported, (2) anterior cruciate ligament deficiency and reconstruction significantly alter the lower extremity gait pattern, (3) the gait parameters shift towards the normal value pattern, and (4) the re-establishment of pre-injury gait patterns--including the normal biphase of muscles--takes at least 8 months to occur.

  14. Gait Patterns in Twins with Cerebral Palsy: Similarities and Development over Time after Multilevel Surgery

    ERIC Educational Resources Information Center

    van Drongelen, Stefan; Dreher, Thomas; Heitzmann, Daniel W. W.; Wolf, Sebastian I.

    2013-01-01

    To examine gait patterns and gait quality, 7 twins with cerebral palsy were measured preoperatively and after surgical intervention. The aim was to study differences and/or similarities in gait between twins, the influence of personal characteristics and birth conditions, and to describe the development of gait over time after single event…

  15. Effect of Rhythmic Auditory Stimulation on Hemiplegic Gait Patterns

    PubMed Central

    Shin, Yoon-Kyum; Chong, Hyun Ju

    2015-01-01

    Purpose The purpose of our study was to investigate the effect of gait training with rhythmic auditory stimulation (RAS) on both kinematic and temporospatial gait patterns in patients with hemiplegia. Materials and Methods Eighteen hemiplegic patients diagnosed with either cerebral palsy or stroke participated in this study. All participants underwent the 4-week gait training with RAS. The treatment was performed for 30 minutes per each session, three sessions per week. RAS was provided with rhythmic beats using a chord progression on a keyboard. Kinematic and temporospatial data were collected and analyzed using a three-dimensional motion analysis system. Results Gait training with RAS significantly improved both proximal and distal joint kinematic patterns in hip adduction, knee flexion, and ankle plantar flexion, enhancing the gait deviation index (GDI) as well as ameliorating temporal asymmetry of the stance and swing phases in patients with hemiplegia. Stroke patients with previous walking experience demonstrated significant kinematic improvement in knee flexion in mid-swing and ankle dorsiflexion in terminal stance. Among stroke patients, subacute patients showed a significantly increased GDI score compared with chronic patients. In addition, household ambulators showed a significant effect on reducing anterior tilt of the pelvis with an enhanced GDI score, while community ambulators significantly increased knee flexion in mid-swing phase and ankle dorsiflexion in terminal stance phase. Conclusion Gait training with RAS has beneficial effects on both kinematic and temporospatial patterns in patients with hemiplegia, providing not only clinical implications of locomotor rehabilitation with goal-oriented external feedback using RAS but also differential effects according to ambulatory function. PMID:26446657

  16. Age-dependent gait abnormalities in mice lacking the Rnf170 gene linked to human autosomal-dominant sensory ataxia.

    PubMed

    Kim, Youngsoo; Kim, Seong Hun; Kim, Kook Hwan; Chae, Sujin; Kim, Chanki; Kim, Jeongjin; Shin, Hee-Sup; Lee, Myung-Shik; Kim, Daesoo

    2015-12-20

    Really interesting new gene (RING) finger protein 170 (RNF170) is an E3 ubiquitin ligase known to mediate ubiquitination-dependent degradation of type-I inositol 1,4,5-trisphosphate receptors (ITPR1). It has recently been demonstrated that a point mutation of RNF170 gene is linked with autosomal-dominant sensory ataxia (ADSA), which is characterized by an age-dependent increase of walking abnormalities, a rare genetic disorder reported in only two families. Although this mutant allele is known to be dominant, the functional identity thereof has not been clearly established. Here, we generated mice lacking Rnf170 (Rnf170(-/-)) to evaluate the effect of its loss of function in vivo. Remarkably, Rnf170(-/-) mice began to develop gait abnormalities in old age (12 months) in the form of asynchronous stepping between diagonal limb pairs with a fixed step sequence during locomotion, while age-matched wild-type mice showed stable gait patterns using several step sequence repertoires. As reported in ADSA patients, they also showed a reduced sensitivity for proprioception and thermal nociception. Protein blot analysis revealed that the amount of Itpr1 protein was significantly elevated in the cerebellum and spinal cord but intact in the cerebral cortex in Rnf170(-/-) mice. These results suggest that the loss of Rnf170 gene function mediates ADSA-associated phenotypes and this gives insights on the cure of patients with ADSA and other age-dependent walking abnormalities.

  17. Multi-complexity measures for early detection and monitoring of neurological abnormalities from gait time series

    NASA Astrophysics Data System (ADS)

    Gavrishchaka, Valeriy; Davis, Kristina; Senyukova, Olga

    2013-10-01

    Recently, we have proposed to use complementary complexity measures discovered by boosting-like ensemble learning for the enhancement of quantitative indicators dealing with necessarily short physiological time series. We have confirmed robustness of such multi-complexity measures for heart rate variability analysis with the emphasis on detection of emerging and intermittent cardiac abnormalities. Here we demonstrate that such ensemble-based approach could be also effective in discovering universal meta-indicators for early detection and convenient monitoring of neurological abnormalities using gait time series.

  18. Quantifying Parkinson's disease progression by simulating gait patterns

    NASA Astrophysics Data System (ADS)

    Cárdenas, Luisa; Martínez, Fabio; Atehortúa, Angélica; Romero, Eduardo

    2015-12-01

    Modern rehabilitation protocols of most neurodegenerative diseases, in particular the Parkinson Disease, rely on a clinical analysis of gait patterns. Currently, such analysis is highly dependent on both the examiner expertise and the type of evaluation. Development of evaluation methods with objective measures is then crucial. Physical models arise as a powerful alternative to quantify movement patterns and to emulate the progression and performance of specific treatments. This work introduces a novel quantification of the Parkinson disease progression using a physical model that accurately represents the main gait biomarker, the body Center of Gravity (CoG). The model tracks the whole gait cycle by a coupled double inverted pendulum that emulates the leg swinging for the single support phase and by a damper-spring System (SDP) that recreates both legs in contact with the ground for the double phase. The patterns generated by the proposed model are compared with actual ones learned from 24 subjects in stages 2,3, and 4. The evaluation performed demonstrates a better performance of the proposed model when compared with a baseline model(SP) composed of a coupled double pendulum and a mass-spring system. The Frechet distance measured differences between model estimations and real trajectories, showing for stages 2, 3 and 4 distances of 0.137, 0.155, 0.38 for the baseline and 0.07, 0.09, 0.29 for the proposed method.

  19. Can Bracing Affect Altered Gait Patterns in Femoroacetabular Impingement

    PubMed Central

    Safran, Marc R.; Rylander, Jonathan; Shu, Beatrice; Andriacchi, Thomas P.

    2013-01-01

    Objectives: Altered gait patterns have been identified in patients with Femoroacetabular impingement (FAI), a 2nd order reversal in mid stance, that has been shown to be corrected with arthroscopic FAI surgery. Currently, most feel there is no adequate conservative treatment for this malady. The goal of this study is to determine if the gait abnormalities seen with femoroacetabular impingement (FAI) can be modified with bracing. Methods: Eight individuals (4 Male, 34.5 ± 12.8 y.o., 24.0±2.3 BMI) who were diagnosed with FAI after reporting to clinic with groin pain were enrolled in this study. The study was approved by the University Internal Review Board before participants were enrolled. History, clinical exam, and imaging including an AP pelvis and cross table lateral radiograph of the affected hip and MR-arthrogram of the affected hip were utilized to make the diagnosis. Participants who enrolled had primarily unilateral hip symptoms, had positive impingement and labral stress tests on the affected side and were free of other lower extremity, back, and spine disorders. Three dimensional lower limb kinematics were collected using a camera and forceplate system with the subjects wearing reflective markers on anatomical landmarks. Participants were tested prior to surgery. Hip kinematics were collected for the symptomatic limb while the patients walked at a self selected normal walking speed, slowly jogged, and ascended a two stair setup. Three trials for each activity were completed with and without wearing a brace that was designed to externally rotate the femur in the treatment of patellofemoral disorders for a total of 6 trials per activity. Peak hip flexion, extension, abduction, adduction, internal rotation, and external rotation were calculated over the stance phase for each trial. Averages were calculated over the 3 trials for each activity both with and without the brace. Intra-subject differences were compared between the braced and unbraced trials

  20. Benign acute childhood myositis--a rare cause of abnormal gait.

    PubMed

    Hall, Gregory; Schranz, Craig I

    2014-02-01

    Benign acute childhood myositis is a rare postviral myositis seen in school-aged children after a common upper respiratory infection (URI), most commonly caused by influenza [J Microbiol Immunol Infect 2004;37:95-98]. Predominantly seen in boys, this condition causes bilateral calf tenderness and pain with ambulation, often presenting as a refusal to bear weight. To avoid activation within the gastroc-soleus complex, the child will frequently compensate with a “Frankenstein gait,” described as a stiff-legged posture with shuffling gait [CMAJ 2009;181:711-713]. The child may also walk on his toes or refuse to walk at all. This refusal to bear weight can be alarming to both providers and parents, resulting in extensive workups. We present the case of a 5-year-old boy who presented to the emergency department with a chief complaint of leg pain and refusal to walk. Further history revealed a resolved URI approximately 5 days prior. He was noted to have an elevated creatinine kinase with no evidence of renal insufficiency. He had no progression or complications, and his symptoms resolved spontaneously with minimal supportive treatment. Benign acute childhood myositis should be considered within the broad differential that surrounds a limping child or one who refuses to bear weight. Having insight into the condition with its characteristic gait abnormalities and associated URI history can often prevent extensive workups and be treated supportively in the outpatient setting. PMID:24126025

  1. Gait recovery pattern of unilateral lower limb amputees during rehabilitation.

    PubMed

    Baker, P A; Hewison, S R

    1990-08-01

    The aim of this study was to determine the rate at which gait recovery as measured by temporal distance factors (velocity and symmetry) occurs in unilateral lower limb amputees. A microcomputer foot switch system was used to record the gait patterns of twenty subjects, mean age 65.1 years. The initial measurement was taken when the subject was capable of walking 6 metres with an interim prosthesis within the parallel bars. The patient sample as a whole was analyzed and subjects were further divided into four groups, depending on ambulatory aid required at discharge. Group A, n = 3 used no aid, Group B, n = 5 used a single stick, Group C, n = 6 used 2 single sticks and Group D, n = 5 required frames. A one way analysis of variance (F = 4.55, p = 0.02) showed a significant difference between the Groups, (A and D, B and D, C and D). The major velocity increase occurs within the first 30 days of the gait training programme. Overall about 55% increase in velocity can be expected within the first fifteen day period followed by an additional 30% between days 15-30. A moderately strong correlation (r = 0.78) was found between initial and discharge velocity. The correlation between initial and discharge symmetry was weaker (r = 0.50). PMID:2235305

  2. Variations In Gait Patterns Of Runners: Relationship To Anthropometric Measurements

    NASA Astrophysics Data System (ADS)

    Adelsberg, S.; Tauber, C.; Au, J.; Pugh, J.

    1983-07-01

    High-speed computerized motion analysis was used to assess the running parameters of a group of runners. Anthropometric measurements were taken on the group of runners in an effort to provide possible correlations between running style, speed, and anthropometry. The most consistent correlation was between speed and stride length. Femur length and stride length was only highly correlated for the runners at the fastest speeds. The faster runners also had a gait pattern characterized by significantly lower ground contact time than that of the slower runners. Of prime importance in running is behavior of the body during float phase, and mediated by anthropometry and the biomechanical characteristics of the stance phase.

  3. Technique and Observation of Angular Gait Patterns in Running

    PubMed Central

    Sykes, K.

    1975-01-01

    A technique for the biomechanical analysis of running is described with specific reference to the angular displacement patterns of the lower limb. From high speed cine film recording profile views of the running gait, the Thigh, Knee and Ankle angles are measured during one complete cycle. Results are presented in the form of vector-space diagrams, namely Thigh-Knee angle and Knee-Ankle angle cyclograms. The diagrams are interpreted and some experimental observations are presented and discussed. The technique provides a useful research tool and a very good `teaching asset' for biomechanical studies of movement.

  4. The Interrater Reliability of the Modified Gait Abnormality Rating Scale for Use with People with Intellectual Disability

    ERIC Educational Resources Information Center

    Hale, Leigh; McIlraith, Lucy; Miller, Clare; Stanley-Clarke, Terri; George, Rebecca

    2010-01-01

    Background: Researching falls in persons with ID is limited by difficulties in applying standardised balance outcome measures. The modified Gait Abnormality Rating Scale (GARS-M), developed to identify falls risk in older adults, requires only that the participant walks and thus may be a feasible falls research tool to use with people with ID. In…

  5. Categorization of gait patterns in adults with cerebral palsy: a clustering approach.

    PubMed

    Roche, Nicolas; Pradon, Didier; Cosson, Julie; Robertson, Johanna; Marchiori, Claire; Zory, Raphael

    2014-01-01

    Gait patterns in adults with cerebral palsy have, to our knowledge, never been assessed. This contrasts with the large number of studies which have attempted to categorize gait patterns in children with cerebral palsy. Several methodological approaches have been developed to objectively classify gait patterns in patients with central nervous system lesions. These methods enable the identification of groups of patients with common underlying clinical problems. One method is cluster analysis, a multivariate statistical method which is used to classify an entire data set into homogeneous groups or "clusters". The aim of this study was to determine, using cluster analysis, the principal gait patterns which can be found in adults with cerebral palsy. Data from 3D motion analyses of 44 adults with cerebral palsy were included. A hierarchical cluster analysis was used to subgroup the different gait patterns based on spatiotemporal and kinematic parameters in the sagittal and frontal planes. Five clusters were identified (C1-C5) among which, 3 subgroups were determined, based on spontaneous gait speed (C1/C2: slow, C3/C4: moderate and C5: almost normal). The different clusters were related to specific kinematic parameters that can be assessed in routine clinical practice. These 5 classifications can be used to follow changes in gait patterns throughout growth and aging as well to assess the effects of different treatments (physiotherapy, surgery, botulinum toxin, etc.) on gait patterns in adults with cerebral palsy.

  6. Quantitative Gait Analysis Using a Motorized Treadmill System Sensitively Detects Motor Abnormalities in Mice Expressing ATPase Defective Spastin.

    PubMed

    Connell, James W; Allison, Rachel; Reid, Evan

    2016-01-01

    The hereditary spastic paraplegias (HSPs) are genetic conditions in which there is progressive axonal degeneration in the corticospinal tract. Autosomal dominant mutations, including nonsense, frameshift and missense changes, in the gene encoding the microtubule severing ATPase spastin are the most common cause of HSP in North America and northern Europe. In this study we report quantitative gait analysis using a motorized treadmill system, carried out on mice knocked-in for a disease-associated mutation affecting a critical residue in the Walker A motif of the spastin ATPase domain. At 4 months and at one year of age homozygous mutant mice had a number of abnormal gait parameters, including in stride length and stride duration, compared to heterozygous and wild-type littermates. Gait parameters in heterozygous animals did not differ from wild-type littermates. We conclude that quantitative gait analysis using the DigiGait system sensitively detects motor abnormalities in a hereditary spastic paraplegia model, and would be a useful method for analyzing the effects of pharmacological treatments for HSP.

  7. Daily changes of individual gait patterns identified by means of support vector machines.

    PubMed

    Horst, F; Kramer, F; Schäfer, B; Eekhoff, A; Hegen, P; Nigg, B M; Schöllhorn, W I

    2016-09-01

    Despite the common knowledge about the individual character of human gait patterns and about their non-repeatability, little is known about their stability, their interactions and their changes over time. Variations of gait patterns are typically described as random deviations around a stable mean curve derived from groups, which appear due to noise or experimental insufficiencies. The purpose of this study is to examine the nature of intrinsic inter-session variability in more detail by proving separable characteristics of gait patterns between individuals as well as within individuals in repeated measurement sessions. Eight healthy subjects performed 15 gait trials at a self-selected speed on eight days within two weeks. For each trial, the time-continuous ground reaction forces and lower body kinematics were quantified. A total of 960 gait patterns were analysed by means of support vector machines and the coefficient of multiple correlation. The results emphasise the remarkable amount of individual characteristics in human gait. Support vector machines results showed an error-free assignment of gait patterns to the corresponding individual. Thus, differences in gait patterns between individuals seem to be persistent over two weeks. Within the range of individual gait patterns, day specific characteristics could be distinguished by classification rates of 97.3% and 59.5% for the eight-day classification of lower body joint angles and ground reaction forces, respectively. Hence, gait patterns can be assumed not to be constant over time and rather exhibit discernible daily changes within previously stated good repeatability. Advantages for more individual and situational diagnoses or therapy are identified.

  8. Lack of tryptophan hydroxylase-1 in mice results in gait abnormalities.

    PubMed

    Suidan, Georgette L; Duerschmied, Daniel; Dillon, Gregory M; Vanderhorst, Veronique; Hampton, Thomas G; Wong, Siu Ling; Voorhees, Jaymie R; Wagner, Denisa D

    2013-01-01

    The role of peripheral serotonin in nervous system development is poorly understood. Tryptophan hydroxylase-1 (TPH1) is expressed by non-neuronal cells including enterochromaffin cells of the gut, mast cells and the pineal gland and is the rate-limiting enzyme involved in the biosynthesis of peripheral serotonin. Serotonin released into circulation is taken up by platelets via the serotonin transporter and stored in dense granules. It has been previously reported that mouse embryos removed from Tph1-deficient mothers present abnormal nervous system morphology. The goal of this study was to assess whether Tph1-deficiency results in behavioral abnormalities. We did not find any differences between Tph1-deficient and wild-type mice in general motor behavior as tested by rotarod, grip-strength test, open field and beam walk. However, here we report that Tph1 (-/-) mice display altered gait dynamics and deficits in rearing behavior compared to wild-type (WT) suggesting that tryptophan hydroxylase-1 expression has an impact on the nervous system. PMID:23516593

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

    PubMed

    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.

  10. 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

  11. The modified gait abnormality rating scale in patients with a conversion disorder: a reliability and responsiveness study.

    PubMed

    Vandenberg, Justin M; George, Deanna R; O'Leary, Andrea J; Olson, Lindsay C; Strassburg, Kaitlyn R; Hollman, John H

    2015-01-01

    Individuals with conversion disorder have neurologic symptoms that are not identified by an underlying organic cause. Often the symptoms manifest as gait disturbances. The modified gait abnormality rating scale (GARS-M) may be useful for quantifying gait abnormalities in these individuals. The purpose of this study was to examine the reliability, responsiveness and concurrent validity of GARS-M scores in individuals with conversion disorder. Data from 27 individuals who completed a rehabilitation program were included in this study. Pre- and post-intervention videos were obtained and walking speed was measured. Five examiners independently evaluated gait performance according to the GARS-M criteria. Inter- and intrarater reliability of GARS-M scores were estimated with intraclass correlation coefficients (ICCs). Responsiveness was estimated with the minimum detectable change (MDC). Pre- to post-treatment changes in GARS-M scores were analyzed with a dependent t-test. The correlation between GARS-M scores and walking speed was analyzed to assess concurrent validity. GARS-M scores were quantified with good-to-excellent inter- (ICC = 0.878) and intrarater reliability (ICC = 0.989). The MDC was 2 points. Mean GARS-M scores decreased from 7 ± 5 at baseline to 1 ± 2 at discharge (t26 = 7.411, p < 0.001) and 85% of patients improved beyond the MDC. Furthermore, GARS-M scores and walking speed measurements were moderately correlated (r = -0.582, p = 0.004), indicating that the GARS-M has acceptable concurrent validity. Our findings provide evidence that the GARS-M scores are reliable, valid and responsive for quantifying gait abnormalities in patients with conversion disorder. GARS-M scores provide objective measures upon which treatment effects can be assessed.

  12. An Ambulatory Method of Identifying Anterior Cruciate Ligament Reconstructed Gait Patterns

    PubMed Central

    Patterson, Matthew R.; Delahunt, Eamonn; Sweeney, Kevin T.; Caulfield, Brian

    2014-01-01

    The use of inertial sensors to characterize pathological gait has traditionally been based on the calculation of temporal and spatial gait variables from inertial sensor data. This approach has proved successful in the identification of gait deviations in populations where substantial differences from normal gait patterns exist; such as in Parkinsonian gait. However, it is not currently clear if this approach could identify more subtle gait deviations, such as those associated with musculoskeletal injury. This study investigates whether additional analysis of inertial sensor data, based on quantification of gyroscope features of interest, would provide further discriminant capability in this regard. The tested cohort consisted of a group of anterior cruciate ligament reconstructed (ACL-R) females and a group of non-injured female controls, each performed ten walking trials. Gait performance was measured simultaneously using inertial sensors and an optoelectronic marker based system. The ACL-R group displayed kinematic and kinetic deviations from the control group, but no temporal or spatial deviations. This study demonstrates that quantification of gyroscope features can successfully identify changes associated with ACL-R gait, which was not possible using spatial or temporal variables. This finding may also have a role in other clinical applications where small gait deviations exist. PMID:24451464

  13. An ambulatory method of identifying anterior cruciate ligament reconstructed gait patterns.

    PubMed

    Patterson, Matthew R; Delahunt, Eamonn; Sweeney, Kevin T; Caulfield, Brian

    2014-01-01

    The use of inertial sensors to characterize pathological gait has traditionally been based on the calculation of temporal and spatial gait variables from inertial sensor data. This approach has proved successful in the identification of gait deviations in populations where substantial differences from normal gait patterns exist; such as in Parkinsonian gait. However, it is not currently clear if this approach could identify more subtle gait deviations, such as those associated with musculoskeletal injury. This study investigates whether additional analysis of inertial sensor data, based on quantification of gyroscope features of interest, would provide further discriminant capability in this regard. The tested cohort consisted of a group of anterior cruciate ligament reconstructed (ACL-R) females and a group of non-injured female controls, each performed ten walking trials. Gait performance was measured simultaneously using inertial sensors and an optoelectronic marker based system. The ACL-R group displayed kinematic and kinetic deviations from the control group, but no temporal or spatial deviations. This study demonstrates that quantification of gyroscope features can successfully identify changes associated with ACL-R gait, which was not possible using spatial or temporal variables. This finding may also have a role in other clinical applications where small gait deviations exist.

  14. A New Classification of Diabetic Gait Pattern Based on Cluster Analysis of Biomechanical Data

    PubMed Central

    Sawacha, Zimi; Guarneri, Gabriella; Avogaro, Angelo; Cobelli, Claudio

    2010-01-01

    Background The diabetic foot, one of the most serious complications of diabetes mellitus and a major risk factor for plantar ulceration, is determined mainly by peripheral neuropathy. Neuropathic patients exhibit decreased stability while standing as well as during dynamic conditions. A new methodology for diabetic gait pattern classification based on cluster analysis has been proposed that aims to identify groups of subjects with similar patterns of gait and verify if three-dimensional gait data are able to distinguish diabetic gait patterns from one of the control subjects. Method The gait of 20 nondiabetic individuals and 46 diabetes patients with and without peripheral neuropathy was analyzed [mean age 59.0 (2.9) and 61.1(4.4) years, mean body mass index (BMI) 24.0 (2.8), and 26.3 (2.0)]. K-means cluster analysis was applied to classify the subjects' gait patterns through the analysis of their ground reaction forces, joints and segments (trunk, hip, knee, ankle) angles, and moments. Results Cluster analysis classification led to definition of four well-separated clusters: one aggregating just neuropathic subjects, one aggregating both neuropathics and non-neuropathics, one including only diabetes patients, and one including either controls or diabetic and neuropathic subjects. Conclusions Cluster analysis was useful in grouping subjects with similar gait patterns and provided evidence that there were subgroups that might otherwise not be observed if a group ensemble was presented for any specific variable. In particular, we observed the presence of neuropathic subjects with a gait similar to the controls and diabetes patients with a long disease duration with a gait as altered as the neuropathic one. PMID:20920432

  15. Gait patterns in a community-dwelling population aged 50 years and older.

    PubMed

    Verlinden, V J A; van der Geest, J N; Hoogendam, Y Y; Hofman, A; Breteler, M M B; Ikram, M A

    2013-04-01

    Poor gait is an important risk factor for falls and associated with higher morbidity and mortality. It is well established that older age is associated with worse gait, but it remains unclear at what age this association is first seen. Moreover, previous studies focused mainly on normal walking, but gait also encompasses turning and tandem walking. In a large study of community-dwelling middle-aged and elderly persons we investigated the association of age with gait, focusing on normal walking, turning and tandem walking. In 1500 persons aged 50 years and over, we measured gait using an electronic walkway. Participants performed normal walks, turning and a tandem walk. With principal components analysis of 30 variables we summarized gait into five known gait factors: Rhythm, Variability, Phases, Pace and Base of Support; and uncovered two novel gait factors: Tandem and Turning. The strongest associations with age were found for Variability (difference in Z-score -0.29 per 10 years increase (95% confidence interval: -0.34; -0.24)), Phases (-0.31 per 10 years (-0.36; -0.27)) and Tandem (-0.25 per 10 years (-0.30; -0.20)). Additionally, these factors already showed association with the youngest age groups, from 55 to 60 years of age and older. Our study shows that Variability, Phases and Tandem have the strongest association with age and are the earliest to demonstrate a poorer gait pattern with higher age. Future research should further investigate how these gait factors relate with gait-related diseases in their earliest stages.

  16. Fractal gait patterns are retained after entrainment to a fractal stimulus.

    PubMed

    Rhea, Christopher K; Kiefer, Adam W; Wittstein, Matthew W; Leonard, Kelsey B; MacPherson, Ryan P; Wright, W Geoffrey; Haran, F Jay

    2014-01-01

    Previous work has shown that fractal patterns in gait can be altered by entraining to a fractal stimulus. However, little is understood about how long those patterns are retained or which factors may influence stronger entrainment or retention. In experiment one, participants walked on a treadmill for 45 continuous minutes, which was separated into three phases. The first 15 minutes (pre-synchronization phase) consisted of walking without a fractal stimulus, the second 15 minutes consisted of walking while entraining to a fractal visual stimulus (synchronization phase), and the last 15 minutes (post-synchronization phase) consisted of walking without the stimulus to determine if the patterns adopted from the stimulus were retained. Fractal gait patterns were strengthened during the synchronization phase and were retained in the post-synchronization phase. In experiment two, similar methods were used to compare a continuous fractal stimulus to a discrete fractal stimulus to determine which stimulus type led to more persistent fractal gait patterns in the synchronization and post-synchronization (i.e., retention) phases. Both stimulus types led to equally persistent patterns in the synchronization phase, but only the discrete fractal stimulus led to retention of the patterns. The results add to the growing body of literature showing that fractal gait patterns can be manipulated in a predictable manner. Further, our results add to the literature by showing that the newly adopted gait patterns are retained for up to 15 minutes after entrainment and showed that a discrete visual stimulus is a better method to influence retention.

  17. Walking pattern classification and walking distance estimation algorithms using gait phase information.

    PubMed

    Wang, Jeen-Shing; Lin, Che-Wei; Yang, Ya-Ting C; Ho, Yu-Jen

    2012-10-01

    This paper presents a walking pattern classification and a walking distance estimation algorithm using gait phase information. A gait phase information retrieval algorithm was developed to analyze the duration of the phases in a gait cycle (i.e., stance, push-off, swing, and heel-strike phases). Based on the gait phase information, a decision tree based on the relations between gait phases was constructed for classifying three different walking patterns (level walking, walking upstairs, and walking downstairs). Gait phase information was also used for developing a walking distance estimation algorithm. The walking distance estimation algorithm consists of the processes of step count and step length estimation. The proposed walking pattern classification and walking distance estimation algorithm have been validated by a series of experiments. The accuracy of the proposed walking pattern classification was 98.87%, 95.45%, and 95.00% for level walking, walking upstairs, and walking downstairs, respectively. The accuracy of the proposed walking distance estimation algorithm was 96.42% over a walking distance.

  18. A chronic mouse model of Parkinson’s disease has a reduced gait pattern certainty

    PubMed Central

    Kurz, Max J.; Pothakos, Konstantinos; Jamaluddin, Sakeena; Scott-Pandorf, Melissa; Arellano, Chris; Lau, Yuen-Sum

    2007-01-01

    The purpose of this investigation was to determine if a chronic Parkinson’s disease mouse model will display less certainty in its gait pattern due to basal ganglia dysfunction. A chronic Parkinson’s disease mouse model was induced by injecting male C57/BL mice with 10 doses of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (25 mg/kg) (MPTP) and probenecid (250 mg/kg) (P) over 5 weeks. This chronic model produces a severe and persistent loss of nigrostriatal neurons resulting in dopamine depletion and locomotor impairment. The control mice were treated with probenecid alone. Fifteen weeks after the last MPTP/P treatment, the mice were videotaped in the sagittal plane with a digital camera (60 Hz) as they ran on a motorized treadmill at a speed of 10 m/min. The indices of gait and gait variability were calculated. Stride length was significantly (p = 0.016) more variable in the chronic MPTP/P mice. Additionally, the chronic MPTP/P mice had a statistically less certain gait pattern when compared to the control mice (p = 0.02). These results suggest that variability in the gait pattern can be used to evaluate changes in neural function. Additionally, our results imply that disorder of the basal ganglia results in less certainty in modulating the descending motor command that controls the gait pattern. PMID:17977658

  19. The effectiveness of voluntary modifications of gait pattern to reduce the knee adduction moment.

    PubMed

    van den Noort, Josien C; Schaffers, Ilse; Snijders, Jasper; Harlaar, Jaap

    2013-06-01

    It has been suggested to use gait modifications in the retraining of patients with knee osteoarthritis (OA), in order to reduce the external knee adduction moment (KAdM). This study focused on the effect of walking speed, foot position and trunk sway, and on the 3D knee moments. Gait analyses of fourteen healthy volunteers were performed in a gait laboratory. Subjects walked at three different speeds in their normal gait pattern, as well as with toe-in and toe-out gait and with medio-lateral trunk sway at a self-selected speed. Fast walking speed increased the KAdM (17-30%) and flexion moment (32%). A slower walking speed did not decrease the KAdM. Toe-in mainly decreased the KAdM (45%) and the transverse moment (38%) during early stance. Toe-out decreased the KAdM during late stance (56%), but increased the KAdM during early stance and midstance (21-24%), due to decreased endorotation of the hip with knee flexion. Trunk sway decreased the KAdM during early stance and midstance (31-33%). Gait modifications mainly affected the KAdM, but changes in sagittal and transverse knee moments and kinematics were also observed. This indicates that, when estimating knee load, taking only the frontal plane kinetics into consideration may lead to erroneous simplifications. No conclusive beneficial effects were found in any of the gait modifications throughout the entire stance phase.

  20. Effects of gastrocnemius fascia lengthening on gait pattern in children with cerebral palsy using the gait profile score.

    PubMed

    Ferreira, Luiz Alfredo Braun; Cimolin, Veronica; Costici, Pier Francesco; Albertini, Giorgio; Oliveira, Claudia Santos; Galli, Manuela

    2014-05-01

    The aim of the present study was to investigate the efficacy of the GPS regarding the quantification of changes in gait following the gastrocnemius fascia lengthening in children with CP. Nineteen children with CP were selected and evaluated in the preoperative period (PRE session) and approximately one year postoperatively (POST session; mean 13.1 ± 5.1 months) using 3D gait analysis and computing the GPS and GVSs. As the GPS represents the difference between the patient's data and the average from the reference dataset, the higher the value of GPS is, more compromised gait of the subject. A statistically significant improvement in mean GPS was found in the POST session (PRE: 13.38 ± 5°; POST: 10.26 ± 2.41°; p<0.05), with an improvement close to 23%. Moreover, the GVSs demonstrated statistically significant improvements in ankle dorsi-plantarflexion (PRE: 22.20 ± 16.36°; POST: 11.50 ± 6.57°; p<0.05) and pelvic rotation (PRE: 9.53 ± 3.87°; POST: 6.47 ± 2.98°; p<0.05). A strong correlation (r=0.75; p<0.05) was found between the preoperative GPS and the percentage of GPS improvement. The results demonstrated that the gastrocnemius fascia lengthening produced a global gait pattern improvement, as showed by the GPS value, which decreased after surgery. Besides this, the GVS permitted to better evidence the joints more compromised by the pathology and their improvement due to the surgery, in this case not only the GVS of the ankle joint but also of the pelvis were characterized by higher GVS values.

  1. Micro-Doppler characteristics of elderly gait patterns with walking aids

    NASA Astrophysics Data System (ADS)

    Amin, Moeness G.; Ahmad, Fauzia; Zhang, Yimin D.; Boashash, Boualem

    2015-05-01

    In this paper, we analyze the micro-Doppler signatures of elderly gait patterns in the presence of walking aids using radars. The signatures are based on real data experiments conducted in a laboratory environment using human subjects walking with a walking cane and a walker. Short-time Fourier transform is used to provide the local signal behavior over frequency and to detail the changes in the micro-Doppler signatures over time. Intrinsic differences in the Doppler and micro-Doppler signatures of the elderly gait observed with and without the use of a walking aid are highlighted. Features that capture these differences can be effective in discriminating gait with walking aids from normal human gait.

  2. VASCULAR OCCLUSION AFFECTS GAIT VARIABILITY PATTERNS OF HEALTHY YOUNGER AND OLDER INDIVIDUALS

    PubMed Central

    Myers, Sara A.; Johanning, Jason M.; Pipinos, Iraklis I.; Schmid, Kendra K.; Stergiou, Nicholas

    2012-01-01

    Insufficient blood flow is one possible mechanism contributing to altered gait patterns in lower extremity peripheral arterial disease (PAD). Previously, our laboratory found that induced occlusion alters gait variability patterns in healthy young individuals. However the effect of age was not explored. The purpose of this study was to account for age by investigating gait variability following induced vascular occlusion in healthy older individuals and to identify amount of change from baseline to post vascular occlusion between younger and older individuals. Thirty healthy younger individuals and 30 healthy older individuals walked on a treadmill during baseline and post vascular occlusion conditions while lower extremity joint kinematics were captured. Vascular occlusion was induced by thigh cuffs inflated bilaterally on the upper thighs. Amount and temporal structure of gait variability was assessed. Older individuals exhibited significantly increased values of temporal structure of variability post vascular occlusion. Post vascular occlusion values were similar between younger and older individuals after adjusting for baseline measurements. Results show blood flow contributes to altered gait variability. However alterations were less severe than previously documented in symptomatic PAD patients, suggesting that neuromuscular problems in the lower extremities of PAD patients also contribute to gait alterations in these patients. PMID:23053301

  3. Feature reduction and multi-classification of different assistive devices according to the gait pattern.

    PubMed

    Martins, Maria; Santos, Cristina; Costa, Lino; Frizera, Anselmo

    2016-01-01

    Total knee arthroplasty (TKA) is a surgical procedure used in patients with Osteoarthritis to improve their state. An understanding about how gait patterns differ from patient to patient and are influenced by the assistive device (AD) that is prescribed is still missing. This article focuses on such purpose. Standard walker, crutches and rollator were tested. Symmetric indexes of spatiotemporal and postural control features were calculated. In order to select the important features which can discriminate the differences among the ADs, different techniques for feature selection are investigated. Classification is handled by Multi-class Support Vector Machine. Results showed that rollator provides a more symmetrical gait and crutches demonstrated to be the worst. Relatively to postural control parameters, standard walker is the most stable and crutches are the worst AD. This means that, depending on the patient's problem and the recovery goal, different ADs should be used. After selecting a set of 16 important features, through correlation, it was demonstrated that they provide important quantitative information about the functional capacity, which is not represented by velocity, cadence and clinical scales. Also, they were capable of distinguishing the gait patterns influenced by each AD, showing that each patient has different needs during recovery. Implications of Rehabilitation An understanding about how gait patterns of post-surgical patients differ from person to person and how they are influenced by the type of device that is prescribed during their recovery might help in physical therapy. Research specifically addressing these issues is still missing. Inter-limb asymmetry and postural control features can be evaluated in an outpatient setting, supplying important additional information about individual gait pattern, which is not represented by gait velocity, cadence and scales usually used. The features calculated in this study are able to provide

  4. Complex muscle vibration patterns to induce gait-like lower-limb movements: proof of concept.

    PubMed

    Duclos, Cyril; Kemlin, Claire; Lazert, David; Gagnon, Dany; Dyer, Joseph-Omer; Forget, Robert

    2014-01-01

    Muscle vibrations can induce motor responses and illusions of complex movements. However, inducing gait-like cyclical movements and illusions requires the application of multiple fast alternating vibrations to lower-limb muscles. The objectives were (1) to test the feasibility of delivering complex vibrations in a time-organized manner and (2) to illustrate the possibility of inducing alternate gait-in-place-like movements using these vibrations. Patterns of vibration, produced by 12 vibrators applied bilaterally on the flexor and extensor muscle groups of the lower limbs, were based on normal gait kinematics. We tested 1 s and 2 s cycle patterns of vibration. Vibrator responses were assessed using auto- and crosscorrelations and frequency analyses based on accelerometry measurements, and compared between patterns. High auto- (>0.8) and crosscorrelation (>0.6) coefficients demonstrated a good response by the vibrators to the control signal. Vibrations induced cyclical, low-amplitude stepping-in-place movements that mimicked alternate walking movements with both legs, with 1 s and 2 s cycle durations, in one nondisabled participant and one participant with American Spinal Injury Association Impairment Scale B spinal cord injury standing, relaxed, with body-weight support. Electromechanical vibrators can deliver complex cyclical vibrations and trigger gait-like lower-limb movements. These results warrant the application of these vibration patterns on individuals with sensorimotor impairments to test their potential in gait rehabilitation.

  5. 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.

  6. Simulation of Parkinsonian gait by fusing trunk learned patterns and a lower limb first order model

    NASA Astrophysics Data System (ADS)

    Cárdenas, Luisa; Martínez, Fabio; Romero, Eduardo

    2015-01-01

    Parkinson's disease is a neurodegenerative disorder that progressively affects the movement. Gait analysis is therefore crucial to determine a disease degree as well as to orient the diagnosis. However, gait examination is completely subjective and therefore prone to errors or misinterpretations, even with a great expertise. In addition, the conventional evaluation follows up general gait variables, which amounts to ignore subtle changes that definitely can modify the history of the treatment. This work presents a functional gait model that simulates the center of gravity trajectory (CoG) for different Parkinson disease stages. This model mimics the gait trajectory by coupling two models: a double pendulum (single stance phase) and a spring-mass model (double stance). Realistic simulations for different Parkinson disease stages are then obtained by integrating to the model a set of trunk bending patterns, learned from real patients. The proposed model was compared with the CoG of real Parkinson gaits in stages 2, 3, 4 achieving a correlation coefficient of 0.88, 0.92 and 0.86, respectively.

  7. Effect of cadence regulation on muscle activation patterns during robot assisted gait: a dynamic simulation study.

    PubMed

    Hussain, Shahid; Xie, Sheng Q; Jamwal, Prashant K

    2013-03-01

    Cadence or stride frequency is an important parameter being controlled in gait training of neurologically impaired subjects. The aim of this study was to examine the effects of cadence variation on muscle activation patterns during robot assisted unimpaired gait using dynamic simulations. A twodimensional (2-D) musculoskeletal model of human gait was developed considering eight major muscle groups along with existing ground contact force (GCF) model. A 2-D model of a robotic orthosis was also developed which provides actuation to the hip, knee and ankle joints in the sagittal plane to guide subjects limbs on reference trajectories. A custom inverse dynamics algorithm was used along with a quadratic minimization algorithm to obtain a feasible set of muscle activation patterns. Predicted patterns of muscle activations during slow, natural and fast cadence were compared and the mean muscle activations were found to be increasing with an increase in cadence. The proposed dynamic simulation provide important insight into the muscle activation variations with change in cadence during robot assisted gait and provide the basis for investigating the influence of cadence regulation on neuromuscular parameters of interest during robot assisted gait.

  8. Automatic characterization of the Parkinson disease by classifying the ipsilateral coordination and spatiotemporal gait patterns

    NASA Astrophysics Data System (ADS)

    Sarmiento, Fernanda; Martínez, Fabio; Romero, Eduardo

    2015-01-01

    Traditionally, the Parkinson disease is diagnosed and followed up by conventional clinical tests that are fully dependent on the expert experience. The diffuse boundary between normal and early Parkinson stages and the high variability of gait patterns difficult any objective characterization of this disease. An automatic characterization of the disease is herein proposed by mixing up different measures of the ipsilateral coordination and spatiotemporal gait patterns which are then classified with a classical support vector machine. The strategy was evaluated in a population with Parkinson and healthy control subjects, obtaining an average accuracy of 87% for the task of classification.

  9. Fractal Gait Patterns Are Retained after Entrainment to a Fractal Stimulus

    PubMed Central

    Rhea, Christopher K.; Kiefer, Adam W.; Wittstein, Matthew W.; Leonard, Kelsey B.; MacPherson, Ryan P.; Wright, W. Geoffrey; Haran, F. Jay

    2014-01-01

    Previous work has shown that fractal patterns in gait can be altered by entraining to a fractal stimulus. However, little is understood about how long those patterns are retained or which factors may influence stronger entrainment or retention. In experiment one, participants walked on a treadmill for 45 continuous minutes, which was separated into three phases. The first 15 minutes (pre-synchronization phase) consisted of walking without a fractal stimulus, the second 15 minutes consisted of walking while entraining to a fractal visual stimulus (synchronization phase), and the last 15 minutes (post-synchronization phase) consisted of walking without the stimulus to determine if the patterns adopted from the stimulus were retained. Fractal gait patterns were strengthened during the synchronization phase and were retained in the post-synchronization phase. In experiment two, similar methods were used to compare a continuous fractal stimulus to a discrete fractal stimulus to determine which stimulus type led to more persistent fractal gait patterns in the synchronization and post-synchronization (i.e., retention) phases. Both stimulus types led to equally persistent patterns in the synchronization phase, but only the discrete fractal stimulus led to retention of the patterns. The results add to the growing body of literature showing that fractal gait patterns can be manipulated in a predictable manner. Further, our results add to the literature by showing that the newly adopted gait patterns are retained for up to 15 minutes after entrainment and showed that a discrete visual stimulus is a better method to influence retention. PMID:25221981

  10. Learning new gait patterns: Exploratory muscle activity during motor learning is not predicted by motor modules.

    PubMed

    Ranganathan, Rajiv; Krishnan, Chandramouli; Dhaher, Yasin Y; Rymer, William Z

    2016-03-21

    The motor module hypothesis in motor control proposes that the nervous system can simplify the problem of controlling a large number of muscles in human movement by grouping muscles into a smaller number of modules. Here, we tested one prediction of the modular organization hypothesis by examining whether there is preferential exploration along these motor modules during the learning of a new gait pattern. Healthy college-aged participants learned a new gait pattern which required increased hip and knee flexion during the swing phase while walking in a lower-extremity robot (Lokomat). The new gait pattern was displayed as a foot trajectory in the sagittal plane and participants attempted to match their foot trajectory to this template. We recorded EMG from 8 lower-extremity muscles and we extracted motor modules during both baseline walking and target-tracking using non-negative matrix factorization (NMF). Results showed increased trajectory variability in the first block of learning, indicating that participants were engaged in exploratory behavior. Critically, when we examined the muscle activity during this exploratory phase, we found that the composition of motor modules changed significantly within the first few strides of attempting the new gait pattern. The lack of persistence of the motor modules under even short time scales suggests that motor modules extracted during locomotion may be more indicative of correlated muscle activity induced by the task constraints of walking, rather than reflecting a modular control strategy.

  11. Changes in plantar load distribution and gait pattern following foot drop correction in leprosy affected patients.

    PubMed

    Karmakar, Mrinmoy; Joshua, Jerry; Mahato, Nidhu

    2015-09-01

    This study was done to compare the changes in plantar load (weight distribution) and gait patterns before and after tibialis posterior transfer surgery in people affected by leprosy. Changes in gait patterns were observed and proportionate changes in plantar load were quantified using data captured by a baropodometer. All the eight patients who underwent tibialis posterior transfer surgery in 2013 in our hospital were included in the study. In addition to the regular pre-operative and post-operative assessments, the patients also underwent baropodometric evaluation. There was a significant change in plantar load at the heel, lateral border and forefoot. Using the foot pressure scan, it was noted that the progression of the centre of mass (displayed graphically as 'the gait line') was also affected by the altered pattern of weight distribution. This study reiterates the importance of tibialis posterior transfer because: it restores the normal gait pattern of 1, 2, 3 (where 1 is heel strike, 2 is mid foot contact and 3 is forefoot contact) and provides a more uniform distribution of planter load. PMID:26665356

  12. A descriptive analysis of the upper limb patterns during gait in individuals with cerebral palsy.

    PubMed

    Bonnefoy-Mazure, A; Sagawa, Y; Lascombes, P; De Coulon, G; Armand, S

    2014-11-01

    Patients with cerebral palsy (CP) are characterized by a large diversity of gait deviations; thus, lower limb movements during gait have been well-analyzed in the literature. However, the question of upper limb movements and, more particularly, arm movements during gait has received less attention for CP patients as a function of the disease type (Hemiplegic, HE or Diplegic, DI). Thus, the aim of this study was to investigate upper limb movements for a large group of CP patients; we used a retrospective search, including upper limb kinematic parameters and 92 CP patients (42 females and 50 males, mean±standard deviation (SD); age: 15.2±6.7 years). The diagnoses consisted of 48 HE and 44 DI. A control group of 15 subjects (7 females and 8 males, age: 18.4±8.4 years) was included in the study to provide normal gait data. For the DI patients and CG, 88 arms and 30 arms were analyzed, respectively. For the HE patients, 48 affected arms and 48 non-affected arms were analyzed. The kinematic parameters selected and analyzed were shoulder elevation angles; elbow flexion angles; thorax tilt and obliquity angles; hand vertical and anterior-posterior movements; and arm angles. Several gait parameters were also analyzed, such as the gait profile score (GPS) and normalized speed. Statistical analyses were performed to compare CG with the affected and non-affected upper limbs of HE patients and with the two upper limbs of DI patients. The results show that HE and DI patients adopt abnormal upper limb movements. However, DI patients have greater shoulder, elbow, thorax and arm angle movements compared with HE patients. However, HE patients adopt different movements between their affected and non-affected arms. Thus, the patients used their upper limbs to optimize their gait more where gait deviations were more important. These observations confirm that the upper limbs must be integrated into rehabilitation programs to improve inter-limb coordination. PMID:25084472

  13. Dependence of gait pattern on the type of coupling between hind- and forelimb generators: modelling study.

    PubMed

    Zmysłowski, W; Kasicki, S

    1982-01-01

    Dependence of gait pattern on the way of possible coupling between fore and hindlimb girdles was investigated. This dependence was analysed using the analog model of neuronal net of spinal generator. Both nets (i.e., for fore and hind girdles) could be synchronized by any coupling between the executive and intrinsic elements. However, only few of them assured generation of patterns corresponding to physiological gaits. Patterns corresponding to walk and trot were obtained with inhibitory connections from hind intrinsic elements to fore executive ones. Pace was obtained at the coupling connections directed from hind executive elements to fore ones. To obtain gallop it was necessary to couple fore executive elements with hind ones by inhibitory connections.

  14. A new training algorithm using artificial neural networks to classify gender-specific dynamic gait patterns.

    PubMed

    Andrade, Andre; Costa, Marcelo; Paolucci, Leopoldo; Braga, Antônio; Pires, Flavio; Ugrinowitsch, Herbert; Menzel, Hans-Joachim

    2015-01-01

    The aim of this study was to present a new training algorithm using artificial neural networks called multi-objective least absolute shrinkage and selection operator (MOBJ-LASSO) applied to the classification of dynamic gait patterns. The movement pattern is identified by 20 characteristics from the three components of the ground reaction force which are used as input information for the neural networks in gender-specific gait classification. The classification performance between MOBJ-LASSO (97.4%) and multi-objective algorithm (MOBJ) (97.1%) is similar, but the MOBJ-LASSO algorithm achieved more improved results than the MOBJ because it is able to eliminate the inputs and automatically select the parameters of the neural network. Thus, it is an effective tool for data mining using neural networks. From 20 inputs used for training, MOBJ-LASSO selected the first and second peaks of the vertical force and the force peak in the antero-posterior direction as the variables that classify the gait patterns of the different genders.

  15. Gait and its assessment in psychiatry

    PubMed Central

    Sanders, Richard D.

    2010-01-01

    Gait reflects all levels of nervous system function. In psychiatry, gait disturbances reflecting cortical and subcortical dysfunction are often seen. Observing spontaneous gait, sometimes augmented by a few brief tests, can be highly informative. The authors briefly review the neuroanatomy of gait, review gait abnormalities seen in psychiatric and neurologic disorders, and describe the assessment of gait. PMID:20805918

  16. Expressing gait-line symmetry in able-bodied gait

    PubMed Central

    Jeleń, Piotr; Wit, Andrzej; Dudziński, Krzysztof; Nolan, Lee

    2008-01-01

    Background Gait-lines, or the co-ordinates of the progression of the point of application of the vertical ground reaction force, are a commonly reported parameter in most in-sole measuring systems. However, little is known about what is considered a "normal" or "abnormal" gait-line pattern or level of asymmetry. Furthermore, no reference databases on healthy young populations are available for this parameter. Thus the aim of this study is to provide such reference data in order to allow this tool to be better used in gait analysis. Methods Vertical ground reaction force data during several continuous gait cycles were collected using a Computer Dyno Graphy in-sole system® for 77 healthy young able-bodied subjects. A curve (termed gait-line) was obtained from the co-ordinates of the progression of the point of application of the force. An Asymmetry Coefficient Curve (AsC) was calculated between the mean gait-lines for the left and right foot for each subject. AsC limits of ± 1.96 and 3 standard deviations (SD) from the mean were then calculated. Gait-line data from 5 individual subjects displaying pathological gait due to disorders relating to the discopathy of the lumbar spine (three with considerable plantarflexor weakness, two with considerable dorsiflexor weakness) were compared to the AsC results from the able-bodied group. Results The ± 1.96 SD limit suggested that non-pathological gait falls within 12–16% asymmetry for gait-lines. Those exhibiting pathological gait fell outside both the ± 1.96 and ± 3SD limits at several points during stance. The subjects exhibiting considerable plantarflexor weakness all fell outside the ± 1.96SD limit from 30–50% of foot length to toe-off while those exhibiting considerable dorsiflexor weakness fell outside the ± 1.96SD limit between initial contact to 25–40% of foot length, and then surpassed the ± 3SD limit after 55–80% of foot length. Conclusion This analysis of gait-line asymmetry provides a reference

  17. Dietary Patterns and Glucose Tolerance Abnormalities in Chinese Adults

    PubMed Central

    He, Yuna; Ma, Guansheng; Zhai, Fengying; Li, Yanping; Hu, Yisong; Feskens, Edith J.M.; Yang, Xiaoguang

    2009-01-01

    OBJECTIVE To investigate the association of the dietary pattern with the presence of newly diagnosed glucose tolerance abnormalities among Chinese adults. RESEARCH DESIGN AND METHODS A total of 20,210 adults aged 45–69 years from the 2002 China National Nutrition and Health Survey were included. Information on dietary intake was collected using a validated food frequency questionnaire. Factor analysis and cluster analysis were used to identify the food factors and dietary pattern clusters. RESULTS Four dietary pattern clusters were identified (“Green Water,” “Yellow Earth,” “Western Adopter,” and “New Affluence”). The prevalence of glucose tolerance abnormalities ranged from 3.9% in the Green Water to 8.0% in the New Affluence. After adjustment for area, age, sex, current smoking, and physical activity, subjects in the Yellow Earth cluster (prevalence ratio 1.22 [95% CI 1.04–1.43]) and New Affluence cluster (2.05 [1.76–2.37]) had significantly higher prevalence rates compared with those for the Green Water cluster. After further adjustment for BMI and waist-to-height ratio, the elevated risk in the New Affluence remained statistically significant. CONCLUSIONS Dietary patterns and food factors are associated with the presence of glucose tolerance abnormalities in China, even independent of obesity. A New Affluence diet is an important modifiable risk factor, which needs attention from the prevention point of view. PMID:19675202

  18. Perception of the Symmetrical Patterning of Human Gait by Infants.

    ERIC Educational Resources Information Center

    Booth, Amy E.; Pinto, Jeannine; Bertenthal, Bennett I.

    2002-01-01

    Two experiments tested infants' sensitivity to properties of point-light displays of a walker and a runner that were equivalent regarding the phasing of limb movements. Found that 3-, but not 5-month-olds, discriminated these displays. When the symmetrical phase-patterning of the runner display was perturbed by advancing two of its limbs by 25…

  19. Hemiparetic Gait.

    PubMed

    Sheffler, Lynne R; Chae, John

    2015-11-01

    The most common pattern of walking impairment poststroke is hemiparetic gait, which is characterized by asymmetry associated with an extensor synergy pattern of hip extension and adduction, knee extension, and ankle plantar flexion and inversion. There are characteristic changes in the spatiotemporal, kinematic and kinetic parameters, and dynamic electromyography patterns in hemiparesis, which may be assessed most accurately in a motion studies laboratory. An understanding of normal human gait is necessary to assess the complex interplay of motor, sensory, and proprioceptive loss; spasticity; and/or ataxia on hemiparetic gait. PMID:26522901

  20. Characterization of gait in late onset Pompe disease.

    PubMed

    McIntosh, Paul T; Case, Laura E; Chan, Justin M; Austin, Stephanie L; Kishnani, Priya

    2015-11-01

    The skeletal muscle manifestations of late-onset Pompe disease (LOPD) cause significant gait impairment. However, the specific temporal and spatial characteristics of abnormal gait in LOPD have not been objectively analyzed or described in the literature. This pilot study evaluated the gait of 22 individuals with LOPD using the GAITRite® temporospatial gait analysis system. The gait parameters were compared to normal reference values, and correlations were made with standard measures of disease progression. The LOPD population demonstrated significant abnormalities in temporospatial parameters of gait including a trend towards decreased velocity and cadence, a prolonged stance phase, prolonged time in double limb support, shorter step and stride length, and a wider base of support. Precise descriptions and analyses of gait abnormalities have much potential in increasing our understanding of LOPD, especially in regards to how its natural history may be modified by the use of enzyme replacement therapy (ERT) and other interventions. Gait analysis may provide a sensitive early marker of the onset of clinical symptoms and signs, offer an additional objective measure of disease progression and the impact of intervention, and serve as a potentially important clinical endpoint. The additional data from comprehensive gait analysis may personalize and optimize physical therapy management, and the clarification of specific gait patterns in neuromuscular diseases could be of clinical benefit in the ranking of a differential diagnosis.

  1. Accuracy of a Custom Physical Activity and Knee Angle Measurement Sensor System for Patients with Neuromuscular Disorders and Gait Abnormalities

    PubMed Central

    Feldhege, Frank; Mau-Moeller, Anett; Lindner, Tobias; Hein, Albert; Markschies, Andreas; Zettl, Uwe Klaus; Bader, Rainer

    2015-01-01

    Long-term assessment of ambulatory behavior and joint motion are valuable tools for the evaluation of therapy effectiveness in patients with neuromuscular disorders and gait abnormalities. Even though there are several tools available to quantify ambulatory behavior in a home environment, reliable measurement of joint motion is still limited to laboratory tests. The aim of this study was to develop and evaluate a novel inertial sensor system for ambulatory behavior and joint motion measurement in the everyday environment. An algorithm for behavior classification, step detection, and knee angle calculation was developed. The validation protocol consisted of simulated daily activities in a laboratory environment. The tests were performed with ten healthy subjects and eleven patients with multiple sclerosis. Activity classification showed comparable performance to commercially available activPAL sensors. Step detection with our sensor system was more accurate. The calculated flexion-extension angle of the knee joint showed a root mean square error of less than 5° compared with results obtained using an electro-mechanical goniometer. This new system combines ambulatory behavior assessment and knee angle measurement for long-term measurement periods in a home environment. The wearable sensor system demonstrated high validity for behavior classification and knee joint angle measurement in a laboratory setting. PMID:25954954

  2. Accuracy of a custom physical activity and knee angle measurement sensor system for patients with neuromuscular disorders and gait abnormalities.

    PubMed

    Feldhege, Frank; Mau-Moeller, Anett; Lindner, Tobias; Hein, Albert; Markschies, Andreas; Zettl, Uwe Klaus; Bader, Rainer

    2015-05-06

    Long-term assessment of ambulatory behavior and joint motion are valuable tools for the evaluation of therapy effectiveness in patients with neuromuscular disorders and gait abnormalities. Even though there are several tools available to quantify ambulatory behavior in a home environment, reliable measurement of joint motion is still limited to laboratory tests. The aim of this study was to develop and evaluate a novel inertial sensor system for ambulatory behavior and joint motion measurement in the everyday environment. An algorithm for behavior classification, step detection, and knee angle calculation was developed. The validation protocol consisted of simulated daily activities in a laboratory environment. The tests were performed with ten healthy subjects and eleven patients with multiple sclerosis. Activity classification showed comparable performance to commercially available activPAL sensors. Step detection with our sensor system was more accurate. The calculated flexion-extension angle of the knee joint showed a root mean square error of less than 5° compared with results obtained using an electro-mechanical goniometer. This new system combines ambulatory behavior assessment and knee angle measurement for long-term measurement periods in a home environment. The wearable sensor system demonstrated high validity for behavior classification and knee joint angle measurement in a laboratory setting.

  3. A new coordination pattern classification to assess gait kinematics when utilising a modified vector coding technique.

    PubMed

    Needham, Robert A; Naemi, Roozbeh; Chockalingam, Nachiappan

    2015-09-18

    A modified vector coding (VC) technique was used to quantify lumbar-pelvic coordination during gait. The outcome measure from the modified VC technique is known as the coupling angle (CA) which can be classified into one of four coordination patterns. This study introduces a new classification for this coordination pattern that expands on a current data analysis technique by introducing the terms in-phase with proximal dominancy, in-phase with distal dominancy, anti-phase with proximal dominancy and anti-phase with distal dominancy. This proposed coordination pattern classification can offer an interpretation of the CA that provides either in-phase or anti-phase coordination information, along with an understanding of the direction of segmental rotations and the segment that is the dominant mover at each point in time. Classifying the CA against the new defined coordination patterns and presenting this information in a traditional time-series format in this study has offered an insight into segmental range of motion. A new illustration is also presented which details the distribution of the CA within each of the coordination patterns and allows for the quantification of segmental dominancy. The proposed illustration technique can have important implications in demonstrating gait coordination data in an easily comprehensible fashion by clinicians and scientists alike. PMID:26303167

  4. A new coordination pattern classification to assess gait kinematics when utilising a modified vector coding technique.

    PubMed

    Needham, Robert A; Naemi, Roozbeh; Chockalingam, Nachiappan

    2015-09-18

    A modified vector coding (VC) technique was used to quantify lumbar-pelvic coordination during gait. The outcome measure from the modified VC technique is known as the coupling angle (CA) which can be classified into one of four coordination patterns. This study introduces a new classification for this coordination pattern that expands on a current data analysis technique by introducing the terms in-phase with proximal dominancy, in-phase with distal dominancy, anti-phase with proximal dominancy and anti-phase with distal dominancy. This proposed coordination pattern classification can offer an interpretation of the CA that provides either in-phase or anti-phase coordination information, along with an understanding of the direction of segmental rotations and the segment that is the dominant mover at each point in time. Classifying the CA against the new defined coordination patterns and presenting this information in a traditional time-series format in this study has offered an insight into segmental range of motion. A new illustration is also presented which details the distribution of the CA within each of the coordination patterns and allows for the quantification of segmental dominancy. The proposed illustration technique can have important implications in demonstrating gait coordination data in an easily comprehensible fashion by clinicians and scientists alike.

  5. Frequencies of initial gait disturbances and falls in 100 Wilson's disease patients.

    PubMed

    Dzieżyc, Karolina; Litwin, Tomasz; Chabik, Grzegorz; Członkowska, Anna

    2015-10-01

    Wilson's disease (WD) is an inherited copper metabolism disorder. Gait disturbances may present with both extrapyramidal and cerebellar patterns. The frequencies of particular types of gait abnormalities have not been established; thus, the aim of the present study was to determine the occurrence of initial gait disturbances among our neurological WD patients. We analyzed 103 WD patients with neurological features at the time of diagnosis, between 2005 and 2014. The neurological and gait assessments were based on the Unified Wilson's Disease Score Scale (UWDRS), from which, we distinguished three main patterns of gait: dystonic, ataxic, or Parkinsonian. All types of gait impairment were assessed using four stages of severity (0=normal, 4=severe). We also obtained each patient's history of falls. Three patients had severe dystonia of limbs and were unable to stand or walk. Gait abnormalities were noted in 59% (59/100) of the remaining group of patients. The most common observed pattern was ataxic gait (45%; 27/59), which presented as impaired tandem in most cases. A mixed gait impairment was observed in 25% (15/59) of patients (ataxic, dystonic, and Parkinsonian, n=8; ataxic and Parkinsonian, n=7), a Parkinsonian gait in 18% (11/59), and a dystonic gait in 10% (6/59) of patients. Falls were noted in 35% of patients, but were occasionally observed in most cases. Gait disturbances are frequent in WD, and reflect the involvement of many brain structures.

  6. Gait Patterns in Hemiplegic Children with Cerebral Palsy: Comparison of Right and Left Hemiplegia

    ERIC Educational Resources Information Center

    Galli, Manuela; Cimolin, Veronica; Rigoldi, Chiara; Tenore, Nunzio; Albertini, Giorgio

    2010-01-01

    The aims of this study are to compare quantitatively the gait strategy of the right and left hemiplegic children with Cerebral Palsy (CP) using gait analysis. The gait strategy of 28 right hemiparetic CP (RHG) and 23 left hemiparetic CP (LHG) was compared using gait analysis (spatio-temporal and kinematic parameters) and considering the hemiplegic…

  7. Patterns of mechanical energy change in tetrapod gait: pendula, springs and work.

    PubMed

    Biewener, Andrew A

    2006-11-01

    Kinematic and center of mass (CoM) mechanical variables used to define terrestrial gaits are compared for various tetrapod species. Kinematic variables (limb phase, duty factor) provide important timing information regarding the neural control and limb coordination of various gaits. Whereas, mechanical variables (potential and kinetic energy relative phase, %Recovery, %Congruity) provide insight into the underlying mechanisms that minimize muscle work and the metabolic cost of locomotion, and also influence neural control strategies. Two basic mechanisms identified by Cavagna et al. (1977. Am J Physiol 233:R243-R261) are used broadly by various bipedal and quadrupedal species. During walking, animals exchange CoM potential energy (PE) with kinetic energy (KE) via an inverted pendulum mechanism to reduce muscle work. During the stance period of running (including trotting, hopping and galloping) gaits, animals convert PE and KE into elastic strain energy in spring elements of the limbs and trunk and regain this energy later during limb support. The bouncing motion of the body on the support limb(s) is well represented by a simple mass-spring system. Limb spring compliance allows the storage and return of elastic energy to reduce muscle work. These two distinct patterns of CoM mechanical energy exchange are fairly well correlated with kinematic distinctions of limb movement patterns associated with gait change. However, in some cases such correlations can be misleading. When running (or trotting) at low speeds many animals lack an aerial period and have limb duty factors that exceed 0.5. Rather than interpreting this as a change of gait, the underlying mechanics of the body's CoM motion indicate no fundamental change in limb movement pattern or CoM dynamics has occurred. Nevertheless, the idealized, distinctive patterns of CoM energy fluctuation predicted by an inverted pendulum for walking and a bouncing mass spring for running are often not clear cut, especially

  8. Exercise Alters Gait Pattern but Not Knee Load in Patients with Knee Osteoarthritis

    PubMed Central

    Lin, Yi-Jia; Chang, Chao-Chin; Chou, You-Cai

    2016-01-01

    Six female patients with bilateral medial knee OA and 6 healthy controls were recruited. Patients with knee OA received a 6-week physiotherapist-supervised and home-based exercise program. Outcome measures, including the Western Ontario and McMaster Universities Arthritis Index and Short Form-36 Health Survey as well as objective biomechanical indices were obtained at baseline and follow-up. After treatment, no significant difference was observed in the knee abductor moment (KAM), lever arm, and ground reaction force. We, however, observed significantly improved pain and physical function as well as altered gait patterns, including a higher hip flexor moment and hip extension angle with a faster walking speed. Although KAM was unchanged, patients with bilateral knee OA showed an improved walking speed and altered the gait pattern after 6 weeks of supervised exercise. This finding suggests that the exercise intervention improves proximal joint mechanics during walking and can be considered for patients with bilateral knee OA. Non-weight-bearing strengthening without external resistance combined with stretching exercise may be an option to improve pain and function in individuals with OA who cannot perform high resistance exercises owing to pain or other reasons. PMID:27725941

  9. Real time gait pattern classification from chest worn accelerometry during a loaded road march.

    PubMed

    Clements, Cynthia M; Buller, Mark J; Welles, Alexander P; Tharion, William J

    2012-01-01

    Accelerometers, whether in smart phones or wearable physiological monitoring systems are becoming widely used to identify movement and activities of free living individuals. Although there has been much work in applying computationally intensive methods to this problem, this paper focuses on developing a real-time gait analysis approach that is intuitive, requires no individual calibration, can be extended to complex gait analysis, and can readily be adopted by ambulatory physiological monitors for use in real time. Chest-mounted tri-axial accelerometry data were collected from sixty-one male U.S. Army Ranger candidates engaged in an 8 or 12 mile loaded (35 Kg packs) timed road march. The pace of the road march was such that volunteers needed to both walk and run. To provide intuitive features we examined the periodic patterns generated from 4s periods of movement from the vertical and longitudinal accelerometer axes. Applying the "eigenfaces" face recognition approach we used Principal Components Analysis to find a single basis vector from 10% of the data (n=6) that could distinguish patterns of walk and run with a classification rate of 95% and 90% (n=55) respectively. Because these movement features are based on a gridded frequency count, the method is applicable for use by body-worn microprocessors. PMID:23365905

  10. Pregnant women exaggerate cautious gait patterns during the transition between level and hill surfaces.

    PubMed

    Gottschall, Jinger S; Sheehan, Riley C; Downs, Danielle S

    2013-10-01

    Falls are the leading cause of nonfatal injury across all age groups and a common incident for pregnant women. Thus, there is a critical demand for research to evaluate if walking strategies in pregnant women change throughout pregnancy in order to effectively intervene and minimize the incidence rate. The aim of the present study was to analyze modifications in temporal-spatial parameters as well as muscle activity during hill walking transitions in pregnant women between gestational week 20 and 32. Based upon previous literature, we hypothesized that in comparison to level walking, the transition strides of pregnant women would be distinct between trimesters in order to accommodate the physical changes within twelve weeks. Thirteen pregnant women completed a series of randomly assigned walking conditions on level and hill surfaces during gestational week 20 and 32. Our results demonstrated that pregnant women modulated their gait patterns throughout pregnancy with additional joint flexion as well as muscle activity at the ankle, knee and hip. In summary, pregnant women exaggerate cautious gait patterns by walking slower and wider with greater joint flexion and muscle activity in order to safely transition between level and hill surfaces.

  11. Spatiotemporal Gait Patterns During Overt and Covert Evaluation in Patients With Parkinson´s Disease and Healthy Subjects: Is There a Hawthorne Effect?

    PubMed

    Robles-García, Verónica; Corral-Bergantiños, Yoanna; Espinosa, Nelson; Jácome, María Amalia; García-Sancho, Carlos; Cudeiro, Javier; Arias, Pablo

    2015-06-01

    Parkinson's disease (PD) and aging lead to gait impairments. Some of the disturbances of gait are focused on step length, cadence, and temporal variability of gait cycle. Under experimental conditions gait can be overtly evaluated, but patients with PD are prone to expectancy effects; thus it seems relevant to determine if such evaluation truly reflects the spontaneous gait pattern in such patients, and also in healthy subjects. Thirty subjects (15 subjects with PD and 15 healthy control subjects) were asked to walk using their natural, preferred gait pattern. In half of the trials subjects were made aware that they were being evaluated (overt evaluation), while in the rest of the trials the evaluation was performed covertly (covert evaluation). During covert evaluation the gait pattern was modified in all groups. Gait speed was significantly increased (P = .022); step cadence and average step length were also significantly modified, the average step length increased (P = .002) and the cadence was reduced (P ≤ .001). Stride cycle time variability was unchanged significantly (P = .084). These changes were not significantly different compared between elderly and young healthy controls either. Due to the small sample size, a note of caution is in order; however, the significant results suggest that covert evaluation of gait might be considered to complement experimental evaluations of gait.

  12. Trendelenburg-Like Gait, Instability and Altered Step Patterns in a Mouse Model for Limb Girdle Muscular Dystrophy 2i.

    PubMed

    Maricelli, Joseph W; Lu, Qi L; Lin, David C; Rodgers, Buel D

    2016-01-01

    Limb-girdle muscular dystrophy type 2i (LGMD2i) affects thousands of lives with shortened life expectancy mainly due to cardiac and respiratory problems and difficulty with ambulation significantly compromising quality of life. Limited studies have noted impaired gait in patients and animal models of different muscular dystrophies, but not in animal models of LGMD2i. Our goal, therefore, was to quantify gait metrics in the fukutin-related protein P448L mutant (P448L) mouse, a recently developed model for LGMD2i. The Noldus CatWalk XT motion capture system was used to identify multiple gait impairments. An average galloping body speed of 35 cm/s for both P448L and C57BL/6 wild-type mice was maintained to ensure differences in gait were due only to strain physiology. Compared to wild-type mice, P448L mice reach maximum contact 10% faster and have 40% more paw surface area during stance. Additionally, force intensity at the time of maximum paw contact is roughly 2-fold higher in P448L mice. Paw swing time is reduced in P448L mice without changes in stride length as a faster swing speed compensates. Gait instability in P448L mice is indicated by 50% higher instances of 3 and 4 paw stance support and conversely, 2-fold fewer instances of single paw stance support and no instance of zero paw support. This leads to lower variation of normal step patterns used and a higher use of uncommon step patterns. Similar anomalies have also been noted in muscular dystrophy patients due to weakness in the hip abductor muscles, producing a Trendelenburg gait characterized by "waddling" and more pronounced shifts to the stance leg. Thus, gait of P448L mice replicates anomalies commonly seen in LGMD2i patients, which is not only potentially valuable for assessing drug efficacy in restoring movement biomechanics, but also for better understanding them. PMID:27627455

  13. 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. PMID:21095924

  14. The effect of footwear mass on the gait patterns of unilateral below-knee amputees.

    PubMed

    Donn, J M; Porter, D; Roberts, V C

    1989-12-01

    This study reports an investigation into the effect of shoe mass on the gait patterns of below-knee (BK) amputees. Ten established unilateral BK, patellar-tendon-bearing prosthesis wearers were assessed using a VICON system of gait analysis. Incremental masses of 50g (up to 200g) were added to the subjects' shoes and data captured as they walked along a 15m measurement field. Coefficients of symmetry of various parameters of the swing phase (knee frequency symmetry, swing time symmetry) were measured and their correlation was tested with the patient's preferred shoe mass and also their own shoe mass, all expressed as a proportion of body mass. The subjects' 'preferred' shoe mass (139-318g) showed the greatest symmetry in all the parameters examined (correlations 0.78-0.81 p less than 0.01 and less than 0.005), whereas there was no correlation between the subjects' own shoe mass (121-325g) and the symmetry coefficients measured.

  15. Early ALS-type gait abnormalities in AMP-dependent protein kinase-deficient mice suggest a role for this metabolic sensor in early stages of the disease.

    PubMed

    Vergouts, Maxime; Marinangeli, Claudia; Ingelbrecht, Caroline; Genard, Geraldine; Schakman, Olivier; Sternotte, Anthony; Calas, André-Guilhem; Hermans, Emmanuel

    2015-12-01

    Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by the selective loss of motoneurons. While the principal cause of the disease remains so far unknown, the onset and progression of the pathology are increasingly associated with alterations in the control of cell metabolism. On the basis of the well-known key roles of 5'-adenosine monophosphate-activated protein kinase (AMPK) in sensing and regulating the intracellular energy status, we hypothesized that mice with a genetic deletion of AMPK would develop locomotor abnormalities that bear similarity with those detected in the very early disease stage of mice carrying the ALS-associated mutated gene hSOD1(G93A). Using an automated gait analysis system (CatWalk), we here show that hSOD1(G93A) mice and age-matched mice lacking the neuronal and skeletal muscle predominant α2 catalytic subunit of AMPK showed an altered gait, clearly different from wild type control mice. Double mutant mice lacking AMPK α2 and carrying hSOD1(G93A) showed the same early gait abnormalities as hSOD1(G93A) mice over an age span of 8 to 16 weeks. Taken together, these data support the concept that altered AMPK function and associated bioenergetic abnormalities could constitute an important component in the early pathogenesis of ALS. Therapeutic interventions acting on metabolic pathways could prove beneficial on early locomotor deficits, which are sensitively detectable in rodent models using the CatWalk system. PMID:26152932

  16. Complexity of human gait pattern at different ages assessed using multiscale entropy: From development to decline.

    PubMed

    Bisi, M C; Stagni, R

    2016-06-01

    Multiscale entropy (MSE) has been applied in biomechanics to evaluate gait stability during human gait and was found to be a promising method for evaluating fall risk in elderly and/or pathologic subjects. The hypothesis of this work is that gait complexity is a relevant parameter of gait development during life, decreasing from immature to mature gait and then increasing again during old age. In order to verify this hypothesis, MSE was applied on trunk acceleration data collected during gait of subjects of different ages: toddlers at the onset of walking, pre-scholar and scholar children, adolescents, young adults, adults and elderlies. MSE was estimated by calculating sample entropy (SEN) on raw unfiltered data of L5 acceleration along the three axes, using values of τ ranging from 1 to 6. In addition, other performance parameters (cadence, stride time variability and harmonic ratio) were evaluated. The results followed the hypothesized trend when MSE was applied on the vertical and/or anteroposterior axis of trunk acceleration: an age effect was found and adult SEN values were significantly different from children ones. From young adults to elderlies a slight increase in SEN values was shown although not statistically significant. While performance gait parameters showed adolescent gait similar to the one of adults, SEN highlighted that their gait maturation is not complete yet. In conclusion, present results suggest that the complexity of gait, evaluated on the sagittal plane, can be used as a characterizing parameter of the maturation of gait control. PMID:27264400

  17. Gait Pattern in Two Rare Genetic Conditions Characterized by Muscular Hypotonia: Ehlers-Danlos and Prader-Willi Syndrome

    ERIC Educational Resources Information Center

    Cimolin, Veronica; Galli, Manuela; Vismara, Luca; Grugni, Graziano; Camerota, Filippo; Celletti, Claudia; Albertini, Giorgio; Rigoldi, Chiara; Capodaglio, Paolo

    2011-01-01

    This study aimed to quantify and compare the gait pattern in Ehlers-Danlos (EDS) and Prader-Willi syndrome (PWS) patients to provide data for developing evidence-based rehabilitation strategies. Twenty EDS and 19 PWS adult patients were evaluated with an optoelectronic system and force platforms for measuring kinematic and kinetic parameters…

  18. 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.

  19. Foot strike pattern and gait changes during a 161-km ultramarathon.

    PubMed

    Kasmer, Mark E; Wren, Jeremy J; Hoffman, Martin D

    2014-05-01

    Foot strike pattern has not been examined during ultramarathons where fatigue or avoidance of impact might have greater effect on foot strike and other gait parameters than in shorter events. In this study, video analysis from 3 level sites at a 161-km ultramarathon was used to: (a) examine changes in foot strike pattern, stride rate, and stride length; (b) determine if foot strike pattern is related to performance; and (c) ascertain if post-race blood creatine phosphokinase (CK) concentrations differ by foot strike pattern. Rear-foot strike (RFS) prevalence was 79.9, 89.0, and 83.9% at 16.5, 90.3, and 161.1 km, respectively. There was a significant distance effect observed between the 90.3 and 161.1-km site for stride rate (p < 0.05) and across all distances for stride length (p < 0.0001), but stride rate and length were stable among the top 20 finishers. There was no effect (p = 0.3) of foot strike pattern on performance. However, top 20 finishers had greater use (p = 0.02) of a non-RFS pattern at 161.1 km than the remaining finishers. There was a trend toward greater post-race blood CK values among non-RFS runners compared with RFS runners, reaching significance at the 90.3 km site (p < 0.05). Thus, the increased RFS prevalence by race midpoint was likely because of greater muscular demands of non-RFS patterns as supported by the higher post-race blood CK concentrations among non-RFS runners. Faster runners maintained higher stride rates and lengths throughout the race and made greater use of a non-RFS pattern at the end of the race compared with the slower finishers.

  20. The effects of biomechanical foot orthoses on the gait patterns of patients with malalignment syndrome as determined by three dimensional gait analysis

    PubMed Central

    Kim, Soo-Hyun; Ahn, Sang-Ho; Jung, Gil-Su; Kim, Jin-Hyun; Cho, Yun-Woo

    2016-01-01

    [Purpose] The biomechanical effects of foot orthoses on malalignment syndrome have not been fully clarified. This experimental investigation was conducted to evaluate the effects of orthoses on the gait patterns of patients with malalignment syndrome. [Subjects and Methods] Ten patients with malalignment syndrome were recruited. For each participant, kinematic and kinetic data were collected under three test conditions: walking barefoot, walking with flat insoles in shoes, and walking with a biomechanical foot orthosis (BFO) in shoes. Gait patterns were analyzed using a motion analysis system. [Results] Spatiotemporal data showed the step and stride lengths when wearing shoes with flat insoles or BFO were significantly greater than when barefoot, and that the walking speed when wearing shoes with BFO was significantly faster than when walking barefoot or with shoes with flat insoles. Kinetic data, showed peak pelvic tilt and obliquity angle were significantly greater when wearing BFO in shoes than when barefoot, and that peak hip flexion/extension angle and peak knee flexion/extension and rotation angles were significantly greater when wearing BFO and flat insoles in shoes than when barefoot. [Conclusion] BFOs can correct pelvic asymmetry while walking. PMID:27190451

  1. The mental representation of the human gait in young and older adults

    PubMed Central

    Stöckel, Tino; Jacksteit, Robert; Behrens, Martin; Skripitz, Ralf; Bader, Rainer; Mau-Moeller, Anett

    2015-01-01

    The link between mental representation (MREP) structures and motor performance has been evidenced for a great variety of movement skills, but not for the human gait. Therefore the present study sought to investigate the cognitive memory structures underlying the human gait in young and older adults. In a first experiment, gait parameters at comfortable gait speed (OptoGait) were compared with gait-specific MREPs (structural dimensional analysis of MREP; SDA-M) in 36 young adults. Participants were divided into a slow- and fast-walking group. The proven relationship between gait speed and executive functions such as working memory led to the hypothesis that gait pattern and MREP differ between slow- and fast-walking adults. In a second experiment, gait performance and MREPs were compared between 24 young (27.9 years) and 24 elderly (60.1 years) participants. As age-related declines in gait performance occur from the seventh decade of life onward, we hypothesized that gait parameters would not be affected until the age of 60 years accompanied by unchanged MREP. Data of experiment one revealed that gait parameters and MREPs differed significantly between slow and fast walkers. Notably, eleven previously incurred musculoskeletal injuries were documented for the slow walkers but only two injuries and one disorder for fast walkers. Experiment two revealed no age-related differences in gait parameters or MREPs between healthy young and older adults. In conclusion, the differences in gait parameters associated with lower comfortable gait speeds are reflected by differences in MREPs, whereby SDA-M data indicate that the single limb support phase may serve as a critical functional period. These differences probably resulted from previously incurred musculoskeletal injuries. Our data further indicate that the human gait and its MREP are stable until the age of 60. SDA-M may be considered as a valuable clinical tool for diagnosis of gait abnormalities and monitoring of

  2. Walking abnormalities

    MedlinePlus

    ... include: Arthritis of the leg or foot joints Conversion disorder (a psychological disorder) Foot problems (such as a ... injuries. For an abnormal gait that occurs with conversion disorder, counseling and support from family members are strongly ...

  3. The Effects of Vibration on the Gait Pattern and Vibration Perception Threshold of Children With Idiopathic Toe Walking.

    PubMed

    Fanchiang, Hsinchen Daniel; Geil, Mark; Wu, Jianhua; Chen, Yu-Ping; Wang, Yong Tai

    2015-07-01

    The effectiveness of idiopathic toe walking treatments is not conclusive. The study investigated the use of vibration as a therapeutic/treatment method for children with idiopathic toe walking. Fifteen children with idiopathic toe walking and 15 typically developing children, aged 4 to 10 years, completed the study. The study included a barefoot gait examination and a vibration perception threshold test before and after standing on a whole body vibration machine for 60 seconds. Temporal-spatial parameters were recorded along with HR32, a calculation designed to distinguish on aspects of the toe-walking pattern. No significant gait pattern differences were found between children with idiopathic toe walking and typically developing children after one bout of vibration intervention. HR32 was found to be a means to identify the toe-walking pattern (P < .001). Hypersensitivity to vibration of children with idiopathic toe walking was not found in the current study (P = .921).

  4. Mitochondrial abnormalities in dermatomyositis: characteristic pattern of neuropathology.

    PubMed

    Alhatou, Mohammed I; Sladky, John T; Bagasra, Omar; Glass, Jonathan D

    2004-08-01

    The objective of the work described in this paper was to evaluate mitochondrial abnormalities in perifascicular atrophic fibers in muscle biopsies from patients with dermatomyositis (DM). We localized cytochrome c oxidase (COX) and succinate dehydrogenase (SDH) histochemically in muscle biopsies of 12 patients with DM, and 12 control patients with neurogenic atrophy. These two histochemical techniques were also combined on single tissue sections in order to accentuate any COX-negative fibers. Eleven out of 12 patients (91.6%) with DM showed histochemical evidence of mitochondrial dysfunction in perifascicular distribution. Similar abnormalities in histochemical staining were not seen in comparably sized myofibers that were atrophic due to denervation. It is concluded that abnormal SDH and COX histochemical activities in atrophic perifascicular fibers are characteristic of dermatomyositis. These abnormal staining characteristics could not be accounted for solely by myofiber atrophy, or by generalized abnormalities in histochemical staining.

  5. Computational intelligent gait-phase detection system to identify pathological gait.

    PubMed

    Senanayake, Chathuri M; Senanayake, S M N Arosha

    2010-09-01

    An intelligent gait-phase detection algorithm based on kinematic and kinetic parameters is presented in this paper. The gait parameters do not vary distinctly for each gait phase; therefore, it is complex to differentiate gait phases with respect to a threshold value. To overcome this intricacy, the concept of fuzzy logic was applied to detect gait phases with respect to fuzzy membership values. A real-time data-acquisition system was developed consisting of four force-sensitive resistors and two inertial sensors to obtain foot-pressure patterns and knee flexion/extension angle, respectively. The detected gait phases could be further analyzed to identify abnormality occurrences, and hence, is applicable to determine accurate timing for feedback. The large amount of data required for quality gait analysis necessitates the utilization of information technology to store, manage, and extract required information. Therefore, a software application was developed for real-time acquisition of sensor data, data processing, database management, and a user-friendly graphical-user interface as a tool to simplify the task of clinicians. The experiments carried out to validate the proposed system are presented along with the results analysis for normal and pathological walking patterns.

  6. Trendelenburg-Like Gait, Instability and Altered Step Patterns in a Mouse Model for Limb Girdle Muscular Dystrophy 2i

    PubMed Central

    Maricelli, Joseph W.; Lu, Qi L.; Lin, David C.; Rodgers, Buel D.

    2016-01-01

    Limb-girdle muscular dystrophy type 2i (LGMD2i) affects thousands of lives with shortened life expectancy mainly due to cardiac and respiratory problems and difficulty with ambulation significantly compromising quality of life. Limited studies have noted impaired gait in patients and animal models of different muscular dystrophies, but not in animal models of LGMD2i. Our goal, therefore, was to quantify gait metrics in the fukutin-related protein P448L mutant (P448L) mouse, a recently developed model for LGMD2i. The Noldus CatWalk XT motion capture system was used to identify multiple gait impairments. An average galloping body speed of 35 cm/s for both P448L and C57BL/6 wild-type mice was maintained to ensure differences in gait were due only to strain physiology. Compared to wild-type mice, P448L mice reach maximum contact 10% faster and have 40% more paw surface area during stance. Additionally, force intensity at the time of maximum paw contact is roughly 2-fold higher in P448L mice. Paw swing time is reduced in P448L mice without changes in stride length as a faster swing speed compensates. Gait instability in P448L mice is indicated by 50% higher instances of 3 and 4 paw stance support and conversely, 2-fold fewer instances of single paw stance support and no instance of zero paw support. This leads to lower variation of normal step patterns used and a higher use of uncommon step patterns. Similar anomalies have also been noted in muscular dystrophy patients due to weakness in the hip abductor muscles, producing a Trendelenburg gait characterized by “waddling” and more pronounced shifts to the stance leg. Thus, gait of P448L mice replicates anomalies commonly seen in LGMD2i patients, which is not only potentially valuable for assessing drug efficacy in restoring movement biomechanics, but also for better understanding them. PMID:27627455

  7. Analysis and Classification of Stride Patterns Associated with Children Development Using Gait Signal Dynamics Parameters and Ensemble Learning Algorithms.

    PubMed

    Wu, Meihong; Liao, Lifang; Luo, Xin; Ye, Xiaoquan; Yao, Yuchen; Chen, Pinnan; Shi, Lei; Huang, Hui; Wu, Yunfeng

    2016-01-01

    Measuring stride variability and dynamics in children is useful for the quantitative study of gait maturation and neuromotor development in childhood and adolescence. In this paper, we computed the sample entropy (SampEn) and average stride interval (ASI) parameters to quantify the stride series of 50 gender-matched children participants in three age groups. We also normalized the SampEn and ASI values by leg length and body mass for each participant, respectively. Results show that the original and normalized SampEn values consistently decrease over the significance level of the Mann-Whitney U test (p < 0.01) in children of 3-14 years old, which indicates the stride irregularity has been significantly ameliorated with the body growth. The original and normalized ASI values are also significantly changing when comparing between any two groups of young (aged 3-5 years), middle (aged 6-8 years), and elder (aged 10-14 years) children. Such results suggest that healthy children may better modulate their gait cadence rhythm with the development of their musculoskeletal and neurological systems. In addition, the AdaBoost.M2 and Bagging algorithms were used to effectively distinguish the children's gait patterns. These ensemble learning algorithms both provided excellent gait classification results in terms of overall accuracy (≥90%), recall (≥0.8), and precision (≥0.8077). PMID:27034952

  8. Analysis and Classification of Stride Patterns Associated with Children Development Using Gait Signal Dynamics Parameters and Ensemble Learning Algorithms

    PubMed Central

    Wu, Meihong; Liao, Lifang; Luo, Xin; Ye, Xiaoquan; Yao, Yuchen; Chen, Pinnan; Shi, Lei; Huang, Hui

    2016-01-01

    Measuring stride variability and dynamics in children is useful for the quantitative study of gait maturation and neuromotor development in childhood and adolescence. In this paper, we computed the sample entropy (SampEn) and average stride interval (ASI) parameters to quantify the stride series of 50 gender-matched children participants in three age groups. We also normalized the SampEn and ASI values by leg length and body mass for each participant, respectively. Results show that the original and normalized SampEn values consistently decrease over the significance level of the Mann-Whitney U test (p < 0.01) in children of 3–14 years old, which indicates the stride irregularity has been significantly ameliorated with the body growth. The original and normalized ASI values are also significantly changing when comparing between any two groups of young (aged 3–5 years), middle (aged 6–8 years), and elder (aged 10–14 years) children. Such results suggest that healthy children may better modulate their gait cadence rhythm with the development of their musculoskeletal and neurological systems. In addition, the AdaBoost.M2 and Bagging algorithms were used to effectively distinguish the children's gait patterns. These ensemble learning algorithms both provided excellent gait classification results in terms of overall accuracy (≥90%), recall (≥0.8), and precision (≥0.8077). PMID:27034952

  9. A preliminary study of modification of gait in real-time using surface electromyography.

    PubMed

    Bolek, Jeffrey E

    2003-06-01

    Modification of abnormal gait was attempted in real-time using a surface electromyography-based protocol to teach recruitment of the anterior tibialis at the correct time in the gait cycle. Two children diagnosed with cerebral palsy were able to learn volitional control of the anterior tibialis as demonstrated by improved clearance of the toe on the swing phase of the gait and newly learned ability to recruit and relax the anterior tibialis. The children were able to walk with the new gait pattern and reproduce the old one at will. Implications for future research in this area are discussed.

  10. Correlation between the knee adduction torque and medial contact force for a variety of gait patterns.

    PubMed

    Zhao, Dong; Banks, Scott A; Mitchell, Kim H; D'Lima, Darryl D; Colwell, Clifford W; Fregly, Benjamin J

    2007-06-01

    The external knee adduction torque has been proposed as a surrogate measure for medial compartment load during gait. However, a direct link between these two quantities has not been demonstrated using in vivo measurement of medial compartment load. This study uses in vivo data collected from a single subject with an instrumented knee implant to evaluate this link. The subject performed five different overground gait motions (normal, fast, slow, wide, and toe-out) with simultaneous collection of instrumented implant, video motion, and ground reaction data. For each trial, the knee adduction torque was measured externally while the total axial force applied to the tibial insert was measured internally. Based on data collected from the same subject performing treadmill gait under fluoroscopic motion analysis, a regression equation was developed to calculate medial contact force from the implant load cell measurements. Correlation analyses were performed for the stance phase and entire gait cycle to quantify the relationship between the knee adduction torque and both the medial contact force and the medial to total contact force ratio. When the entire gait cycle was analyzed, R(2) for medial contact force was 0.77 when all gait trials were analyzed together and between 0.69 and 0.93 when each gait trial was analyzed separately (p < 0.001 in all cases). For medial to total force ratio, R(2) was 0.69 for all trials together and between 0.54 and 0.90 for each trial separately (p < 0.001 in all cases). When only the stance phase was analyzed, R(2) values were slightly lower. These results support the hypothesis that the knee adduction torque is highly correlated with medial compartment contact force and medial to total force ratio during gait.

  11. Developing a portable gait cycle detection system using an inertial sensor and evaluating the accuracy of the gait cycle detection.

    PubMed

    Park, Min-Hwa; Kwak, Ki-Young; Kim, Dong-Wook

    2015-01-01

    Although researches had analyzed gait using small sensors, they analyzed only normal gaits. Thus, a research that can overcome the spatial limitations of the existing motion analyses and diagnose abnormal gaits for medical treatment is needed. Accordingly, this research developed the portable gait detection system that can detect gait using a gyroscope, and evaluated the accuracy of the system. The results showed an average recognition error rate of 1.7% for the normal and abnormal gaits, and confirmed that the gait cycle was detected with a high degree of accuracy. Using these characteristics, we could distinguish or diagnose, and treat, an abnormal gait.

  12. Effect of a nonsurgical treatment program on the gait pattern of idiopathic toe walking: a case report

    PubMed Central

    Szopa, Andrzej; Domagalska-Szopa, Małgorzata; Gallert-Kopyto, Weronika; Kiebzak, Wojciech; Plinta, Ryszard

    2016-01-01

    Background Recent studies have reported many possibilities for the treatment of idiopathic toe walking (ITW); however, none of them have been sufficiently documented. The purpose of this case study was to document the evolution of the gait pattern of a child with severe ITW using the Gillette Gait Index before and after the third and sixth weeks, a nonsurgical treatment program and then every 3 months to 1 year from the start of the treatment. This is significant because the case study shows that a nonsurgical treatment program can be an alternative treatment method for children with severe ITW. Case description The case study involved a 5-year-old boy diagnosed with severe ITW. An orthopedist recommended a surgical treatment, but his parents refused to provide consent. Intervention The subject participated in a 12-week nonsurgical treatment program that used tone-inhibiting casts (TICs) combined with physiotherapy based on neurodevelopmental treatment principles. The treatment protocol included the following: 1) precast preparation; 2) TICs with treatment; and 3) post-cast treatment to improve the gait pattern. Outcomes After treatment with TICs, the range of motion of ankle dorsiflexion during stance had increased, resulting in an almost normalized gait. The patient stopped toe walking for at least 1 year. Discussion This study demonstrates that nonsurgical treatment should be considered first, with surgical options reserved for resistant cases; however, further research is required given the current lack of knowledge about treatment outcomes using TICs and the wide use of this treatment modality in children with ITW. PMID:26937193

  13. Gait in amyotrophic lateral sclerosis: Is gait pattern differently affected in spinal and bulbar onset of the disease during dual task walking?

    PubMed

    Radovanović, Sasa; Milićev, Milena; Perić, Stojan; Basta, Ivana; Kostić, Vladimir; Stević, Zorica

    2014-12-01

    Amyotrophic lateral sclerosis (ALS) is characterized by weakness, fatigue, loss of balance and coordination. The purpose of the study was to examine gait in ALS patients. Gait was compared in ALS with spinal and bulbar onset, while performing dual mental and motor tasks. Dual-task walking was performed by 27 ALS patients, 13 with spinal- and 14 with bulbar-onset disease. Twenty-nine healthy subjects were used as a control group. The subjects performed a basic, simple walking task, dual-motor task, dual-mental task, and combined motor and mental tasks. Results showed that dual-task paradigm has an effect on gait in ALS patients. Gait was differently affected in spinal and bulbar onset of ALS by some of the given tasks. Mental tasks had a larger effect than motor tasks in all gait parameters. In conclusion, both ALS forms have impaired gait in dual tasks. Simple walk in patients with spinal onset shows higher variability of certain gait parameters compared to bulbar-onset patients and controls. Differences in gait could also indicate postural instability and possible falls in complex walking situations.

  14. Noise Effects on the Complex Patterns of Abnormal Heartbeats

    SciTech Connect

    Schulte-Frohlinde, Verena; Ashkenazy, Yosef; Ivanov, Plamen Ch.; Glass, Leon; Goldberger, Ary L.; Stanley, H. Eugene

    2001-08-06

    Patients at high risk for sudden death often exhibit complex heart rhythms in which abnormal heartbeats are interspersed with normal heartbeats. We analyze such a complex rhythm in a single patient over a 12-h period and show that the rhythm can be described by a theoretical model consisting of two interacting oscillators with stochastic elements. By varying the magnitude of the noise, we show that for an intermediate level of noise, the model gives best agreement with key statistical features of the dynamics.

  15. Noise effects on the complex patterns of abnormal heartbeats

    NASA Technical Reports Server (NTRS)

    Schulte-Frohlinde, V.; Ashkenazy, Y.; Ivanov, P. C.; Glass, L.; Goldberger, A. L.; Stanley, H. E.

    2001-01-01

    Patients at high risk for sudden death often exhibit complex heart rhythms in which abnormal heartbeats are interspersed with normal heartbeats. We analyze such a complex rhythm in a single patient over a 12-h period and show that the rhythm can be described by a theoretical model consisting of two interacting oscillators with stochastic elements. By varying the magnitude of the noise, we show that for an intermediate level of noise, the model gives best agreement with key statistical features of the dynamics.

  16. Gait initiation in children with Rett syndrome.

    PubMed

    Isaias, Ioannis Ugo; Dipaola, Mariangela; Michi, Marlies; Marzegan, Alberto; Volkmann, Jens; Rodocanachi Roidi, Marina L; Frigo, Carlo Albino; Cavallari, Paolo

    2014-01-01

    Rett syndrome is an X-linked neurodevelopmental condition mainly characterized by loss of spoken language and a regression of purposeful hand use, with the development of distinctive hand stereotypies, and gait abnormalities. Gait initiation is the transition from quiet stance to steady-state condition of walking. The associated motor program seems to be centrally mediated and includes preparatory adjustments prior to any apparent voluntary movement of the lower limbs. Anticipatory postural adjustments contribute to postural stability and to create the propulsive forces necessary to reach steady-state gait at a predefined velocity and may be indicative of the effectiveness of the feedforward control of gait. In this study, we examined anticipatory postural adjustments associated with gait initiation in eleven girls with Rett syndrome and ten healthy subjects. Muscle activity (tibialis anterior and soleus muscles), ground reaction forces and body kinematic were recorded. Children with Rett syndrome showed a distinctive impairment in temporal organization of all phases of the anticipatory postural adjustments. The lack of appropriate temporal scaling resulted in a diminished impulse to move forward, documented by an impairment in several parameters describing the efficiency of gait start: length and velocity of the first step, magnitude and orientation of centre of pressure-centre of mass vector at the instant of (swing-)toe off. These findings were related to an abnormal muscular activation pattern mainly characterized by a disruption of the synergistic activity of antagonistic pairs of postural muscles. This study showed that girls with Rett syndrome lack accurate tuning of feedforward control of gait.

  17. Patterns of Structural MRI Abnormalities in Deficit and Nondeficit Schizophrenia

    PubMed Central

    Galderisi, Silvana; Quarantelli, Mario; Volpe, Umberto; Mucci, Armida; Cassano, Giovanni Battista; Invernizzi, Giordano; Rossi, Alessandro; Vita, Antonio; Pini, Stefano; Cassano, Paolo; Daneluzzo, Enrico; De Peri, Luca; Stratta, Paolo; Brunetti, Arturo; Maj, Mario

    2008-01-01

    Negative symptoms of schizophrenia have generally been found in association with ventricular enlargement and prefrontal abnormalities. These relationships, however, have not been observed consistently, most probably because negative symptoms are heterogeneous and result from different pathophysiological mechanisms. The concept of deficit schizophrenia (DS) was introduced by Carpenter et al to identify a clinically homogeneous subgroup of patients characterized by the presence of primary and enduring negative symptoms. Findings of brain structural abnormalities reported by magnetic resonance imaging (MRI) studies focusing on DS have been mixed. The present study included 34 patients with DS, 32 with nondeficit schizophrenia (NDS), and 31 healthy comparison subjects, providing the largest set of MRI findings in DS published so far. The Schedule for the Deficit Syndrome was used to categorize patients as DS or NDS patients. The 2 patient groups were matched on age and gender and did not differ on clinical variables, except for higher scores on the negative dimension and more impaired interpersonal relationships in DS than in NDS subjects. Lateral ventricles were larger in NDS than in control subjects but were not enlarged in patients with DS. The cingulate gyri volume was smaller in NDS but not in DS patients as compared with healthy subjects. Both groups had smaller dorsolateral prefrontal cortex and temporal lobes than healthy subjects, but DS patients had significantly less right temporal lobe volume as compared with NDS patients. These findings do not support the hypothesis that DS is the extreme end of a severity continuum within schizophrenia. PMID:17728266

  18. Inducible Expression of a Truncated Form of Tau in Oligodendrocytes Elicits Gait Abnormalities and a Decrease in Myelin: Implications for Selective CNS Degenerative Diseases.

    PubMed

    LoPresti, Patrizia

    2015-11-01

    The cytoskeleton protein Tau present in oligodendrocytes (OLGs) promotes cellular process outgrowth and myelination; whereas abnormally hyperphosphorylated Tau has been shown to be present in the most debilitating form of multiple sclerosis and in selective dementias. This research examined the functional consequences of expressing a truncated form of Tau in OLGs during the second postnatal life. In particular, this truncated form of Tau (∆Tau) retains the Fyn-binding domain but lacks the microtubule-binding domain. Similar to hyperphosphorylated Tau, ∆Tau cannot bind the cytoskeleton and is missorted. The Cre/loxP recombination system was used to generate transgenic (TG) founder lines, which contain a Floxed LacZ-STOP cassette to prevent expression of enhanced green fluorescence protein (EGFP)-∆Tau. The founder lines were then crossed with a Tamoxifen (TM)-inducible proteolipid protein (PLP)-dependent Cre driver line. Myelin PLP is the major myelin protein in the central nervous system (CNS). TM was given at postnatal day (p) 12 for 3 days, and CNS tissues were collected at p22. Only TG mice with both EGFP-∆Tau and Cre manifested an overt phenotype of loss of balance and stumbles starting around p18. CNS tissues obtained from TM-treated EGFP-∆Tau/Cre double transgenic mice had recombined PCR products, GFP, and diminished brain myelin. GFP was expressed in OLGs, but not in neurons or astrocytes. On the contrary, TM-treated TG mice with only one of the two transgenes, i.e., Cre or Tau, did not have recombinant PCR products, GFP, diminished myelin, or abnormal phenotype. Thus, this inducible model shows for the first time that a non-microtubule-associated Tau protein in OLGs elicits both myelin decrease and gait abnormalities, similar to the occurrence in selective demyelinating and neurodegenerative diseases.

  19. Gait Pattern Alterations during Walking, Texting and Walking and Texting during Cognitively Distractive Tasks while Negotiating Common Pedestrian Obstacles

    PubMed Central

    Licence, Sammy; Smith, Robynne; McGuigan, Miranda P.; Earnest, Conrad P.

    2015-01-01

    Objectives Mobile phone texting is a common daily occurrence with a paucity of research examining corresponding gait characteristics. To date, most studies have participants walk in a straight line vs. overcoming barriers and obstacles that occur during regular walking. The aim of our study is to examine the effect of mobile phone texting during periods of cognitive distraction while walking and negotiating barriers synonymous with pedestrian traffic. Methods Thirty participants (18-50y) completed three randomized, counter-balanced walking tasks over a course during: (1) normal walking (control), (2) texting and walking, and (3) texting and walking whilst being cognitively distraction via a standard mathematical test performed while negotiating the obstacle course. We analyzed gait characteristics during course negotiation using a 3-dimensional motion analysis system and a general linear model and Dunnet-Hsu post-hoc procedure the normal walking condition to assess gait characteristic differences. Primary outcomes included the overall time to complete the course time and barrier contact. Secondary outcomes included obstacle clearance height, step frequency, step time, double support phase and lateral deviation. Results Participants took significantly longer (mean ± SD) to complete the course while texting (24.96±4.20 sec) and during cognitive distraction COG (24.09±3.36 sec) vs. normal walking (19.32±2.28 sec; all, P<0.001). No significant differences were noted for barrier contacts (P = 0.28). Step frequency, step time, double support phase and lateral deviation all increased in duration during the texting and cognitive distraction trial. Texting and being cognitively distracted also increased obstacle clearance versus the walking condition (all, P<0.02). Conclusions Texting while walking and/or being cognitively distracted significantly affect gait characteristics concordant to mobile phone usage resulting in a more cautious gate pattern. Future research

  20. Variation in the location of the shoe sole flexion point influences plantar loading patterns during gait

    PubMed Central

    2014-01-01

    Background Several footwear design characteristics are known to have detrimental effects on the foot. However, one characteristic that has received relatively little attention is the point where the sole flexes in the sagittal plane. Several footwear assessment forms assume that this should ideally be located directly under the metarsophalangeal joints (MTPJs), but this has not been directly evaluated. The aim of this study was therefore to assess the influence on plantar loading of different locations of the shoe sole flexion point. Method Twenty-one asymptomatic females with normal foot posture participated. Standardised shoes were incised directly underneath the metatarsophalangeal joints, proximal to the MTPJs or underneath the midfoot. The participants walked in a randomised sequence of the three shoes whilst plantar loading patterns were obtained using the Pedar® in-shoe pressure measurement system. The foot was divided into nine anatomically important masks, and peak pressure (PP), contact time (CT) and pressure time integral (PTI) were determined. A ratio of PP and PTI between MTPJ2-3/MTPJ1 was also calculated. Results Wearing the shoe with the sole flexion point located proximal to the MTPJs resulted in increased PP under MTPJ 4–5 (6.2%) and decreased PP under the medial midfoot compared to the sub-MTPJ flexion point (−8.4%). Wearing the shoe with the sole flexion point located under the midfoot resulted in decreased PP, CT and PTI in the medial and lateral hindfoot (PP: −4.2% and −5.1%, CT: −3.4% and −6.6%, PTI: −6.9% and −5.7%) and medial midfoot (PP: −5.9% CT: −2.9% PTI: −12.2%) compared to the other two shoes. Conclusion The findings of this study indicate that the location of the sole flexion point of the shoe influences plantar loading patterns during gait. Specifically, shoes with a sole flexion point located under the midfoot significantly decrease the magnitude and duration of loading under the midfoot and hindfoot, which

  1. Synergistic combination of clinical and imaging features predicts abnormal imaging patterns of pulmonary infections

    PubMed Central

    Bagci, Ulas; Jaster-Miller, Kirsten; Olivier, Kenneth N.; Yao, Jianhua; Mollura, Daniel J.

    2013-01-01

    We designed and tested a novel hybrid statistical model that accepts radiologic image features and clinical variables, and integrates this information in order to automatically predict abnormalities in chest computed-tomography (CT) scans and identify potentially important infectious disease biomarkers. In 200 patients, 160 with various pulmonary infections and 40 healthy controls, we extracted 34 clinical variables from laboratory tests and 25 textural features from CT images. From the CT scans, pleural effusion (PE), linear opacity (or thickening) (LT), tree-in-bud (TIB), pulmonary nodules, ground glass opacity (GGO), and consolidation abnormality patterns were analyzed and predicted through clinical, textural (imaging), or combined attributes. The presence and severity of each abnormality pattern was validated by visual analysis of the CT scans. The proposed biomarker identification system included two important steps: (i) a coarse identification of an abnormal imaging pattern by adaptively selected features (AmRMR), and (ii) a fine selection of the most important features from the previous step, and assigning them as biomarkers, depending on the prediction accuracy. Selected biomarkers were used to classify normal and abnormal patterns by using a boosted decision tree (BDT) classifier. For all abnormal imaging patterns, an average prediction accuracy of 76.15% was obtained. Experimental results demonstrated that our proposed biomarker identification approach is promising and may advance the data processing in clinical pulmonary infection research and diagnostic techniques. PMID:23930819

  2. Design of Spiking Central Pattern Generators for Multiple Locomotion Gaits in Hexapod Robots by Christiansen Grammar Evolution.

    PubMed

    Espinal, Andres; Rostro-Gonzalez, Horacio; Carpio, Martin; Guerra-Hernandez, Erick I; Ornelas-Rodriguez, Manuel; Sotelo-Figueroa, Marco

    2016-01-01

    This paper presents a method to design Spiking Central Pattern Generators (SCPGs) to achieve locomotion at different frequencies on legged robots. It is validated through embedding its designs into a Field-Programmable Gate Array (FPGA) and implemented on a real hexapod robot. The SCPGs are automatically designed by means of a Christiansen Grammar Evolution (CGE)-based methodology. The CGE performs a solution for the configuration (synaptic weights and connections) for each neuron in the SCPG. This is carried out through the indirect representation of candidate solutions that evolve to replicate a specific spike train according to a locomotion pattern (gait) by measuring the similarity between the spike trains and the SPIKE distance to lead the search to a correct configuration. By using this evolutionary approach, several SCPG design specifications can be explicitly added into the SPIKE distance-based fitness function, such as looking for Spiking Neural Networks (SNNs) with minimal connectivity or a Central Pattern Generator (CPG) able to generate different locomotion gaits only by changing the initial input stimuli. The SCPG designs have been successfully implemented on a Spartan 6 FPGA board and a real time validation on a 12 Degrees Of Freedom (DOFs) hexapod robot is presented. PMID:27516737

  3. Design of Spiking Central Pattern Generators for Multiple Locomotion Gaits in Hexapod Robots by Christiansen Grammar Evolution.

    PubMed

    Espinal, Andres; Rostro-Gonzalez, Horacio; Carpio, Martin; Guerra-Hernandez, Erick I; Ornelas-Rodriguez, Manuel; Sotelo-Figueroa, Marco

    2016-01-01

    This paper presents a method to design Spiking Central Pattern Generators (SCPGs) to achieve locomotion at different frequencies on legged robots. It is validated through embedding its designs into a Field-Programmable Gate Array (FPGA) and implemented on a real hexapod robot. The SCPGs are automatically designed by means of a Christiansen Grammar Evolution (CGE)-based methodology. The CGE performs a solution for the configuration (synaptic weights and connections) for each neuron in the SCPG. This is carried out through the indirect representation of candidate solutions that evolve to replicate a specific spike train according to a locomotion pattern (gait) by measuring the similarity between the spike trains and the SPIKE distance to lead the search to a correct configuration. By using this evolutionary approach, several SCPG design specifications can be explicitly added into the SPIKE distance-based fitness function, such as looking for Spiking Neural Networks (SNNs) with minimal connectivity or a Central Pattern Generator (CPG) able to generate different locomotion gaits only by changing the initial input stimuli. The SCPG designs have been successfully implemented on a Spartan 6 FPGA board and a real time validation on a 12 Degrees Of Freedom (DOFs) hexapod robot is presented.

  4. Design of Spiking Central Pattern Generators for Multiple Locomotion Gaits in Hexapod Robots by Christiansen Grammar Evolution

    PubMed Central

    Espinal, Andres; Rostro-Gonzalez, Horacio; Carpio, Martin; Guerra-Hernandez, Erick I.; Ornelas-Rodriguez, Manuel; Sotelo-Figueroa, Marco

    2016-01-01

    This paper presents a method to design Spiking Central Pattern Generators (SCPGs) to achieve locomotion at different frequencies on legged robots. It is validated through embedding its designs into a Field-Programmable Gate Array (FPGA) and implemented on a real hexapod robot. The SCPGs are automatically designed by means of a Christiansen Grammar Evolution (CGE)-based methodology. The CGE performs a solution for the configuration (synaptic weights and connections) for each neuron in the SCPG. This is carried out through the indirect representation of candidate solutions that evolve to replicate a specific spike train according to a locomotion pattern (gait) by measuring the similarity between the spike trains and the SPIKE distance to lead the search to a correct configuration. By using this evolutionary approach, several SCPG design specifications can be explicitly added into the SPIKE distance-based fitness function, such as looking for Spiking Neural Networks (SNNs) with minimal connectivity or a Central Pattern Generator (CPG) able to generate different locomotion gaits only by changing the initial input stimuli. The SCPG designs have been successfully implemented on a Spartan 6 FPGA board and a real time validation on a 12 Degrees Of Freedom (DOFs) hexapod robot is presented. PMID:27516737

  5. Evaluation of a visual feedback system in gait retraining: a pilot study.

    PubMed

    Hamacher, Daniel; Bertram, Dietrich; Fölsch, Cassandra; Schega, Lutz

    2012-06-01

    Abnormal gait pattern of the frontal plane (i.e. Duchenne gait and Trendelenburg gait) may be caused by a variety of diseases. The aim of this pilot study was to evaluate the instantaneous effect of a visual feedback system on frontal plane pelvis and trunk movements in order to use it in patients with THR in subsequent studies. A total of 24 women (45-65 years) were included in the study. According to acute functional impairments the subjects were assigned to the control group (CG, no gait disorders, n=15, age=59±11 years, BMI=27±4) or to the intervention group (IG, n=9, age=61±4, BMI=29±5), respectively. First, in Measurement 1 (M1) kinematic reference values were captured in a standardized clinical gait analysis (MVN, XSens). Afterwards, the influence of a visual real-time feedback on gait pattern was examined while using the feedback system (M2). While there was a significant difference of IG vs. CG in M1 in the mean inclination regarding pelvis and trunk movements, this was not detected in M2. Therefore it is concluded, especially in subjects with abnormal gait pattern, that the visualization leads to an improvement of the movement pattern of pelvis and trunk in the frontal plane while using the device. PMID:22425191

  6. Characteristic gait patterns in older adults with obesity--results from the Baltimore Longitudinal Study of Aging.

    PubMed

    Ko, Seung-uk; Stenholm, Sari; Ferrucci, Luigi

    2010-04-19

    Obesity in older adults is a growing public health problem. Excess weight causes biomechanical burden to lower extremity joints and contribute to joint pathology. The aim of this study was to identify specific characteristics of gait associated with body mass index (BMI). Preferred and maximum speed walking and related gait characteristics were examined in 164 (50-84 years) participants from Baltimore Longitudinal Study of Aging (BLSA) able to walk unassisted. Participants were divided into three groups based on their BMI: normal weight (19< or =BMI<25 kg/m(2)), overweight (25< or =BMI<30 kg/m(2)) and obese (BMI 30< or =BMI<40 kg/m(2)). Total ankle generative mechanical work expenditure (MWE) in the anterior-posterior (AP) plane was progressively and significantly lower with increase in BMI for both preferred (p=0.026) and maximum speed walking (p<0.001). In the medial-lateral (ML) plane, total knee generative MWE was higher in obese participants in the preferred speed task (p=0.002), and total hip absorptive MWE was higher in obese in both preferred speed (p<0.001) and maximum speed (p=0.002) walking task compared to the normal weight participants. Older adults with obesity show spatiotemporal gait patterns that may help in reducing contact impacts. In addition, in obese persons mechanical energy usages tend to be lower in the AP plane and higher in the ML plane. Since forward progression forces are mainly implicated in normal walking, this pattern found in obese participants is suggestive of lower energetic efficiency.

  7. Patterns of strain and activation in the thigh muscles of goats across gaits during level locomotion.

    PubMed

    Gillis, Gary B; Flynn, John P; McGuigan, Polly; Biewener, Andrew A

    2005-12-01

    Unlike homologous muscles in many vertebrates, which appear to function similarly during a particular mode of locomotion (e.g. red muscle in swimming fish, pectoralis muscle in flying birds, limb extensors in jumping and swimming frogs), a major knee extensor in mammalian quadrupeds, the vastus lateralis, appears to operate differently in different species studied to date. In rats, the vastus undergoes more stretching early in stance than shortening in later stance. In dogs, the reverse is true; more substantial shortening follows small amounts of initial stretching. And in horses, while the vastus strain trajectory is complex, it is characterized mainly by shortening during stance. In this study, we use sonomicrometry and electromyography to study the vastus lateralis and biceps femoris of goats, with three goals in mind: (1) to see how these muscles work in comparison to homologous muscles studied previously in other taxa; (2) to address how speed and gait impact muscle actions and (3) to test whether fascicles in different parts of the same muscle undergo similar length changes. Results indicate that the biceps femoris undergoes substantial shortening through much of stance, with higher strains in walking and trotting [32-33% resting length (L0)] than galloping (22% L0). These length changes occur with increasing biceps EMG intensities as animals increase speed from walking to galloping. The vastus undergoes a stretch-shorten cycle during stance. Stretching strains are higher during galloping (15% L0) than walking and trotting (9% L0). Shortening strains follow a reverse pattern and are greatest in walking (24% L0), intermediate in trotting (20% L0) and lowest during galloping (17% L0). As a result, the ratio of stretching to shortening increases from below 0.5 in walking and trotting to near 1.0 during galloping. This increasing ratio suggests that the vastus does relatively more positive work than energy absorption at the slower speeds compared with galloping

  8. Pattern recognition of abnormal left ventricle wall motion in cardiac MR.

    PubMed

    Lu, Yingli; Radau, Perry; Connelly, Kim; Dick, Alexander; Wright, Graham

    2009-01-01

    There are four main problems that limit application of pattern recognition techniques for recognition of abnormal cardiac left ventricle (LV) wall motion: (1) Normalization of the LV's size, shape, intensity level and position; (2) defining a spatial correspondence between phases and subjects; (3) extracting features; (4) and discriminating abnormal from normal wall motion. Solving these four problems is required for application of pattern recognition techniques to classify the normal and abnormal LV wall motion. In this work, we introduce a normalization scheme to solve the first and second problems. With this scheme, LVs are normalized to the same position, size, and intensity level. Using the normalized images, we proposed an intra-segment classification criterion based on a correlation measure to solve the third and fourth problems. Application of the method to recognition of abnormal cardiac MR LV wall motion showed promising results.

  9. Intralimb Coordination Patterns in Absent, Mild, and Severe Stages of Diabetic Neuropathy: Looking Beyond Kinematic Analysis of Gait Cycle

    PubMed Central

    Yi, Liu Chiao; Sartor, Cristina D.; Souza, Francis Trombini; Sacco, Isabel C. N.

    2016-01-01

    Aim Diabetes Mellitus progressively leads to impairments in stability and joint motion and might affect coordination patterns, mainly due to neuropathy. This study aims to describe changes in intralimb joint coordination in healthy individuals and patients with absent, mild and, severe stages of neuropathy. Methods Forty-seven diabetic patients were classified into three groups of neuropathic severity by a fuzzy model: 18 without neuropathy (DIAB), 7 with mild neuropathy (MILD), and 22 with moderate to severe neuropathy (SVRE). Thirteen healthy subjects were included as controls (CTRL). Continuous relative phase (CRP) was calculated at each instant of the gait cycle for each pair of lower limb joints. Analysis of Variance compared each frame of the CRP time series and its standard deviation among groups (α = 5%). Results For the ankle-hip CRP, the SVRE group presented increased variability at the propulsion phase and a distinct pattern at the propulsion and initial swing phases compared to the DIAB and CTRL groups. For the ankle-knee CRP, the 3 diabetic groups presented more anti-phase ratios than the CTRL group at the midstance, propulsion, and terminal swing phases, with decreased variability at the early stance phase. For the knee-hip CRP, the MILD group showed more in-phase ratio at the early stance and terminal swing phases and lower variability compared to all other groups. All diabetic groups were more in-phase at early the midstance phase (with lower variability) than the control group. Conclusion The low variability and coordination differences of the MILD group showed that gait coordination might be altered not only when frank evidence of neuropathy is present, but also when neuropathy is still incipient. The ankle-knee CRP at the initial swing phase showed distinct patterns for groups from all degrees of neuropathic severity and CTRLs. The ankle-hip CRP pattern distinguished the SVRE patients from other diabetic groups, particularly in the transitional

  10. Gait patterns during different walking conditions in older adults with and without knee osteoarthritis--results from the Baltimore Longitudinal Study of Aging.

    PubMed

    Ko, Seung-uk; Ling, Shari M; Schreiber, Catherine; Nesbitt, Mark; Ferrucci, Luigi

    2011-02-01

    Biomechanical analysis of lower extremity activities while walking at different speeds and in challenging conditions may help to identify specific gait patterns associated with knee osteoarthritis (knee-OA). We hypothesized that individuals with asymptomatic knee-OA have lower ankle activity, while individuals with symptomatic knee-OA have similar or higher ankle activity compared to individuals without knee-OA, and that such differences are enhanced during challenging gait tasks. We tested this hypothesis by examining gait characteristics in multiple gait tasks using data from 153 Baltimore Longitudinal Study of Aging (BLSA) participants (112 without knee-OA, 41 with knee-OA; 53-87 years, 52% women). All participants who could walk unassisted were evaluated in the BLSA gait lab while walking at self-selected speed (usual-walking), at maximum speed (fast-walking) and again at self-selected speed after 30-min of walking activities (usual-walking-after-30 min). Knee range of motion was lower for knee-OA participants in the fast-walking and usual-walking-after-30 min tasks (p<0.030). Ankle range of motion for symptomatic knee-OA was greater compared to asymptomatic knee-OA for all walking tasks (p<0.050). Symptomatic knee-OA had greater generative MWE of the ankle compared to asymptomatic knee-OA (p=0.034), while keeping similar absorptive MWE of the knee when compared to no-OA controls (p=0.151). Symptomatic knee-OA individuals seem to adapt an ankle kinematic gait pattern aimed at avoiding knee pain, by enhancing forward propulsion so to minimize knee joint load. Whether these conditions represent subsequent steps in the causal pathway from knee-OA to changes in gait is still not clear.

  11. Control entropy identifies differential changes in complexity of walking and running gait patterns with increasing speed in highly trained runners.

    PubMed

    McGregor, Stephen J; Busa, Michael A; Skufca, Joseph; Yaggie, James A; Bollt, Erik M

    2009-06-01

    Regularity statistics have been previously applied to walking gait measures in the hope of gaining insight into the complexity of gait under different conditions and in different populations. Traditional regularity statistics are subject to the requirement of stationarity, a limitation for examining changes in complexity under dynamic conditions such as exhaustive exercise. Using a novel measure, control entropy (CE), applied to triaxial continuous accelerometry, we report changes in complexity of walking and running during increasing speeds up to exhaustion in highly trained runners. We further apply Karhunen-Loeve analysis in a new and novel way to the patterns of CE responses in each of the three axes to identify dominant modes of CE responses in the vertical, mediolateral, and anterior/posterior planes. The differential CE responses observed between the different axes in this select population provide insight into the constraints of walking and running in those who may have optimized locomotion. Future comparisons between athletes, healthy untrained, and clinical populations using this approach may help elucidate differences between optimized and diseased locomotor control. PMID:19566269

  12. Control entropy identifies differential changes in complexity of walking and running gait patterns with increasing speed in highly trained runners

    NASA Astrophysics Data System (ADS)

    McGregor, Stephen J.; Busa, Michael A.; Skufca, Joseph; Yaggie, James A.; Bollt, Erik M.

    2009-06-01

    Regularity statistics have been previously applied to walking gait measures in the hope of gaining insight into the complexity of gait under different conditions and in different populations. Traditional regularity statistics are subject to the requirement of stationarity, a limitation for examining changes in complexity under dynamic conditions such as exhaustive exercise. Using a novel measure, control entropy (CE), applied to triaxial continuous accelerometry, we report changes in complexity of walking and running during increasing speeds up to exhaustion in highly trained runners. We further apply Karhunen-Loeve analysis in a new and novel way to the patterns of CE responses in each of the three axes to identify dominant modes of CE responses in the vertical, mediolateral, and anterior/posterior planes. The differential CE responses observed between the different axes in this select population provide insight into the constraints of walking and running in those who may have optimized locomotion. Future comparisons between athletes, healthy untrained, and clinical populations using this approach may help elucidate differences between optimized and diseased locomotor control.

  13. Control entropy identifies differential changes in complexity of walking and running gait patterns with increasing speed in highly trained runners.

    PubMed

    McGregor, Stephen J; Busa, Michael A; Skufca, Joseph; Yaggie, James A; Bollt, Erik M

    2009-06-01

    Regularity statistics have been previously applied to walking gait measures in the hope of gaining insight into the complexity of gait under different conditions and in different populations. Traditional regularity statistics are subject to the requirement of stationarity, a limitation for examining changes in complexity under dynamic conditions such as exhaustive exercise. Using a novel measure, control entropy (CE), applied to triaxial continuous accelerometry, we report changes in complexity of walking and running during increasing speeds up to exhaustion in highly trained runners. We further apply Karhunen-Loeve analysis in a new and novel way to the patterns of CE responses in each of the three axes to identify dominant modes of CE responses in the vertical, mediolateral, and anterior/posterior planes. The differential CE responses observed between the different axes in this select population provide insight into the constraints of walking and running in those who may have optimized locomotion. Future comparisons between athletes, healthy untrained, and clinical populations using this approach may help elucidate differences between optimized and diseased locomotor control.

  14. Animal Gaits and Symmetry

    NASA Astrophysics Data System (ADS)

    Golubitsky, Martin

    2012-04-01

    Many gaits of four-legged animals are described by symmetry. For example, when a horse paces it moves both left legs in unison and then both right legs and so on. The motion is described by two symmetries: Interchange front and back legs, and swap left and right legs with a half-period phase shift. Biologists postulate the existence of a central pattern generator (CPG) in the neuronal system that sends periodic signals to the legs. CPGs can be thought of as electrical circuits that produce periodic signals and can be modeled by systems with symmetry. In this lecture we discuss animal gaits; use gait symmetries to construct a simplest CPG architecture that naturally produces quadrupedal gait rhythms; and make several testable predictions about gaits.

  15. Abnormal Patterns of Tongue-Palate Contact in the Speech of Individuals with Cleft Palate

    ERIC Educational Resources Information Center

    Gibbon, Fiona E.

    2004-01-01

    Individuals with cleft palate, even those with adequate velopharyngeal function, are at high risk for disordered lingual articulation. This article attempts to summarize current knowledge of abnormal tongue-palate contact patterns derived from electropalatographic (EPG) data in speakers with cleft palate. These data, which have been reported in 23…

  16. Relationship between tissue stress during gait in healthy volunteers and patterns of urate deposition and bone erosion in gout: a biomechanical computational modelling study

    PubMed Central

    Dalbeth, Nicola; Deacon, Michelle; Gamble, Gregory D; Mithraratne, Kumar; Fernandez, Justin

    2015-01-01

    Objectives To determine whether patterns of high internal tissue stress during gait are associated with patterns of monosodium urate crystal deposition and bone erosion in gout. Methods We compared patterns of foot von Mises stress predicted computationally during gait in volunteers of normal and high body mass index (BMI) with patterns of urate deposition in gout and asymptomatic hyperuricaemia, and bone erosion in gout using dual-energy and conventional CT data. Results The highest average and peak von Mises stress during gait was observed at the third metatarsal (MT) head. Similar stress patterns were observed for high and low BMI groups. In contrast, for both urate deposition and bone erosion, the first MT head was most frequently affected, with very infrequent involvement of the third MT head. There was no clear relationship between average or peak von Mises stress patterns with patterns of urate deposition or bone erosion (−0.29>r<0.16). Addition of BMI into linear regression models did not alter the findings. Conclusions These data do not support the concept that elevated internal tissue stress during biomechanical loading plays an important role in patterns of monosodium urate crystal deposition or structural damage in gout. PMID:26535140

  17. Movement-related cortical potentials in paraplegic patients: abnormal patterns and considerations for BCI-rehabilitation.

    PubMed

    Xu, Ren; Jiang, Ning; Vuckovic, Aleksandra; Hasan, Muhammad; Mrachacz-Kersting, Natalie; Allan, David; Fraser, Matthew; Nasseroleslami, Bahman; Conway, Bernie; Dremstrup, Kim; Farina, Dario

    2014-01-01

    Non-invasive EEG-based Brain-Computer Interfaces (BCI) can be promising for the motor neuro-rehabilitation of paraplegic patients. However, this shall require detailed knowledge of the abnormalities in the EEG signatures of paraplegic patients. The association of abnormalities in different subgroups of patients and their relation to the sensorimotor integration are relevant for the design, implementation and use of BCI systems in patient populations. This study explores the patterns of abnormalities of movement related cortical potentials (MRCP) during motor imagery tasks of feet and right hand in patients with paraplegia (including the subgroups with/without central neuropathic pain (CNP) and complete/incomplete injury patients) and the level of distinctiveness of abnormalities in these groups using pattern classification. The most notable observed abnormalities were the amplified execution negativity and its slower rebound in the patient group. The potential underlying mechanisms behind these changes and other minor dissimilarities in patients' subgroups, as well as the relevance to BCI applications, are discussed. The findings are of interest from a neurological perspective as well as for BCI-assisted neuro-rehabilitation and therapy.

  18. A 4-Week Neuromuscular Training Program and Gait Patterns at the Ankle Joint

    PubMed Central

    Coughlan, Garrett; Caulfield, Brian

    2007-01-01

    Context: Previous research into the rehabilitation of ankle sprains has primarily focused on outcome measures that do not replicate functional activities, thus making it difficult to extrapolate the results relative to the weight-bearing conditions under which most ankle sprains occur. Objective: To measure the effects of a training program on gait during walking and running in an active athletic population. Design: Matched-pairs, controlled trial. Setting: University motion analysis laboratory. Patients or Other Participants: Ten subjects from an athletic population (7 healthy, 3 with functional ankle instability: age = 25.8 ± 3.9 years, height = 177.6 ± 6.1 cm, mass = 66.8 ± 7.4 kg) and 10 controls matched for age, sex, activity, and ankle instability (7 healthy, 3 with functional ankle instability: age = 27.4 ± 5.8 years, height = 178.7 ± 10.8 cm, mass = 71.6 ± 10.0 kg). Intervention(s): A 4-week neuromuscular training program undertaken by the treatment group. Main Outcome Measure(s): We measured ankle position and velocity in the frontal (x) and sagittal (y) planes in all subjects during treadmill walking and running for the periods 100 milliseconds before heel strike, at heel strike, and 100 milliseconds after heel strike. Results: A 4-week neuromuscular training program resulted in no significant changes in ankle position or velocity during treadmill walking and running. Conclusions: The mechanisms by which neuromuscular training improves function in normal subjects and those with functional ankle instability do not appear to result in measurable changes in gait kinematics. Our findings raise issues regarding methods of ankle sprain rehabilitation and the measurement of their effectiveness in improving functional activities. Further research in a larger population with functional ankle instability is necessary. PMID:17597944

  19. Abnormal Image Detection in Endoscopy Videos Using a Filter Bank and Local Binary Patterns

    PubMed Central

    Nawarathna, Ruwan; Oh, JungHwan; Muthukudage, Jayantha; Tavanapong, Wallapak; Wong, Johnny; de Groen, Piet C.; Tang, Shou Jiang

    2014-01-01

    Finding mucosal abnormalities (e.g., erythema, blood, ulcer, erosion, and polyp) is one of the most essential tasks during endoscopy video review. Since these abnormalities typically appear in a small number of frames (around 5% of the total frame number), automated detection of frames with an abnormality can save physician’s time significantly. In this paper, we propose a new multi-texture analysis method that effectively discerns images showing mucosal abnormalities from the ones without any abnormality since most abnormalities in endoscopy images have textures that are clearly distinguishable from normal textures using an advanced image texture analysis method. The method uses a “texton histogram” of an image block as features. The histogram captures the distribution of different “textons” representing various textures in an endoscopy image. The textons are representative response vectors of an application of a combination of Leung and Malik (LM) filter bank (i.e., a set of image filters) and a set of Local Binary Patterns on the image. Our experimental results indicate that the proposed method achieves 92% recall and 91.8% specificity on wireless capsule endoscopy (WCE) images and 91% recall and 90.8% specificity on colonoscopy images. PMID:25132723

  20. Frequency and patterns of abnormal Pap smears in Sudanese women with infertility: What are the perspectives?

    PubMed Central

    Almobarak, Ahmed O; Elhoweris, Mohammed H; Nour, Hilmi M; Ahmed, Mohammed Abd Allah M; Omer, Al-Fadhil Alobeed; Ahmed, Mohamed H

    2013-01-01

    Background: Pelvic inflammatory disease is one of the major causes of infertility in females. Also, women with infertility are at high-risk of developing cervical intraepithelial lesions or even carcinoma. Aim: To assess the prevalence and patterns of epithelial cell abnormalities in cervical smears in Sudanese infertile and fertile women. Materials and Methods: The present study included 200 cases (women with infertility) of age group 20-60 years who had routine pap smear. A total of 700 fertile women constituted the control group. Results: Among the 200 infertile women, 93.5% reported as negative for intraepithelial lesion or malignancy (NILM), and 6.5% were epithelial cell abnormalities (atypical squamous cells of undetermined significance and above). In the control group 96.6% of the smears reported as NILM and 3.4% as epithelial cell abnormalities. The percentage of abnormal pap smears in the infertile women was significantly higher when compared with the control group. Conclusions: Epithelial cell abnormalities are significantly higher in women with infertility as compared with fertile women. Importantly, inflammatory smears were reported two times more than in the controls. We recommend pap smear as a routine practice for all women assessed for infertility problems. Further studies are necessary to evaluate the incidence of human papilloma virus infections in infertile women with abnormal cervical cytology. PMID:23833398

  1. Gait pattern alterations in older adults associated with type 2 diabetes in the absence of peripheral neuropathy--results from the Baltimore Longitudinal Study of Aging.

    PubMed

    Ko, Seung-uk; Stenholm, Sari; Chia, Chee W; Simonsick, Eleanor M; Ferrucci, Luigi

    2011-10-01

    Diabetes may impact gait mechanics before onset of frank neuropathies and other associated threats to mobility. This study aims to characterize gait pattern alterations of type 2 diabetic adults without peripheral neuropathy during walking at maximum speed (fast-walking) as well as at self-selected speed (usual-walking). One-hundred and eighty-six participants aged 60-87 from the Baltimore Longitudinal Study of Aging (BLSA) able to walk unassisted and without peripheral neuropathy were classified as non-diabetic (N=160) or having type 2 diabetes (N=26). Gait parameters from the fast-walking and usual-walking tests were compared between participants with and without type 2 diabetes. Participants with diabetes had a shorter stride length for fast-walking (p=0.033) and a longer percentage of the gait cycle with the knee in 1st flexion for both fast- and usual-walking (p=0.033, and 0.040, respectively) than non-diabetic participants. Participants with diabetes exhibited a smaller hip range of motion in the sagittal plane during usual-walking compared to non-diabetics (p=0.049). During fast-walking, participants with diabetes used lower ankle generative mechanical work expenditure (MWE) and higher knee absorptive MWE compared to non-diabetic persons (p=0.021, and 0.018, respectively). These findings suggest that individuals with type 2 diabetes without overt peripheral neuropathy exhibit altered and less efficient gait patterns than non-diabetic persons. These alterations are more apparent during walking at a maximum speed indicating that maximum gait testing may be useful for identifying early threats to mobility limitations in older adults with type 2 diabetes.

  2. A mouse model of conduction system patterning abnormalities in heterotaxy syndrome.

    PubMed

    Czosek, Richard J; Haaning, Allison; Ware, Stephanie M

    2010-10-01

    Duplication or absence of parts of the specialized cardiac conduction system in patients with heterotaxy syndrome causes significant clinical disease, but the mechanistic basis by which embryonic disruption of left-right patterning alters conduction system patterning in these patients is not well understood. We sought to determine whether a mouse model of X-linked human heterotaxy recapitulates conduction system abnormalities identified in patients with heterotaxy. Cardiac structure and conduction system patterning were evaluated in Zic3 null embryos from e9.5 to e16.5 using genetic and molecular methods. Severe structural abnormalities involving atrial, ventricular, and conotruncal development were associated with a spectrum of disorganized and ambiguous arrangements throughout the conduction system, including the appearance of duplicated structures. The severity and location of conduction system abnormalities correlated with the severity and location of associated structural heart disease and were identifiable at the earliest stages examined. The Zic3 mouse model provides a novel tool to dissect the mechanistic underpinnings of conduction system patterning and dysfunction and its relationship to cardiovascular malformations, making it a promising model to improve understanding and risk assessment in the clinical arena.

  3. Optimising the effects of rigid ankle foot orthoses on the gait of children with cerebral palsy (CP) - an exploratory trial.

    PubMed

    Jagadamma, Kavi C; Coutts, Fiona J; Mercer, Thomas H; Herman, Janet; Yirrell, Jacqueline; Forbes, Lyndsay; van der Linden, Marietta L

    2014-04-21

    Abstract Purpose: This exploratory trial investigated the effects of rigid ankle foot orthoses (AFO) with an optimally cast Angle of the Ankle in the AFO (AAAFO) on the gait of children with Cerebral Palsy (CP), and whether tuning of the AFO - Footwear Combination (AFO-FC) further affected gait. Methods: Eight children with CP underwent gait analysis and tuning of their AFO-FCs using a 3-D motion analysis system. Comparisons were carried out for selected gait parameters between three conditions - barefoot, non-tuned AFO-FC and tuned AFO-FC. Results: In comparison to barefoot gait, walking with a non-tuned AFO-FC produced significant (p < 0.05) improvements in several key gait parameters. Compared to the non-tuned AFO-FC, on average a tuned AFO-FC produced a significant reduction in peak knee extension and knee ROM during gait. However, when examined as case studies, it was observed that the type of gait pattern demonstrated while wearing a non-tuned AFO-FC affected the outcomes of tuning. Conclusions: The findings of the current study indicate the potential benefits of using rigid AFO-FC with optimal AAAFO and tuning of AFO-FCs. This study emphasises the need for categorising children with CP based on their gait patterns when investigating the effects of interventions such as AFOs. Implications for Rehabilitation Rigid ankle foot orthoses (AFO) cast at an optimal angle to accommodate the length of gastrocnemius muscle may positively influence walking in children with Cerebral Palsy (CP). Tuning of the AFO-Footwear Combination (AFO-FC) has potential benefits to the walking of children with CP, depending on their gait abnormalities. When investigating the effects of interventions such as AFOs, it is important to categorise children with CP based on their gait abnormalities.

  4. The Change in Knee Angle during the Gait by Applying Elastic Tape to the Skin

    PubMed Central

    Yamamoto, Hiroyuki

    2014-01-01

    [Purpose] The aim of this study was to verify how the application of elastic tape to the anterior surface of the thigh changes the knee angle pattern during gait. [Subjects] The subjects were 10 people who showed an abnormal knee angle change pattern during usual walking. They did not show the so-called double knee action. [Methods] Subjects were asked to walk as usual, and then to walk with elastic tape attached to the anterior surface of the thigh. The knee angle was measured during gait with an electronic goniometer. We graphed the temporal changes of the knee angle and compared them with the normal gait pattern. [Results] The knee angle gait pattern of six of the 10 subjects improved after application of the tape and became like a normal gait pattern. The changes in the knee angle resulted from a stimulus via the skin, rather than voluntary muscular adjustment, suggesting that the changes may have originated due to differences in reflexive tensile strength. [Conclusion] In normal speed gait, it is suggested that the knee angle was altered such that it exhibited a normal pattern by applying elastic tape to the anterior surface of the thigh. We suspect that application of the elastic tape may change the muscle tonus. PMID:25140100

  5. Unsupervised Pattern Classifier for Abnormality-Scaling of Vibration Features for Helicopter Gearbox Fault Diagnosis

    NASA Technical Reports Server (NTRS)

    Jammu, Vinay B.; Danai, Kourosh; Lewicki, David G.

    1996-01-01

    A new unsupervised pattern classifier is introduced for on-line detection of abnormality in features of vibration that are used for fault diagnosis of helicopter gearboxes. This classifier compares vibration features with their respective normal values and assigns them a value in (0, 1) to reflect their degree of abnormality. Therefore, the salient feature of this classifier is that it does not require feature values associated with faulty cases to identify abnormality. In order to cope with noise and changes in the operating conditions, an adaptation algorithm is incorporated that continually updates the normal values of the features. The proposed classifier is tested using experimental vibration features obtained from an OH-58A main rotor gearbox. The overall performance of this classifier is then evaluated by integrating the abnormality-scaled features for detection of faults. The fault detection results indicate that the performance of this classifier is comparable to the leading unsupervised neural networks: Kohonen's Feature Mapping and Adaptive Resonance Theory (AR72). This is significant considering that the independence of this classifier from fault-related features makes it uniquely suited to abnormality-scaling of vibration features for fault diagnosis.

  6. Cognition and Gait Show a Selective Pattern of Association Dominated by Phenotype in Incident Parkinson’s Disease

    PubMed Central

    Lord, Sue; Galna, Brook; Coleman, Shirley; Yarnall, Alison; Burn, David; Rochester, Lynn

    2014-01-01

    Reports outlining the association between gait and cognition in Parkinson’s disease (PD) are limited because of methodological issues and a bias toward studying advanced disease. This study examines the association between gait and cognition in 121 early PD who were characterized according to motor phenotype, and 184 healthy older adults. Quantitative gait was captured using a 7 m GAITrite walkway while walking for 2 min under single-task conditions and described by five domains (pace, rhythm, variability, asymmetry, and postural control). Cognitive outcomes were summarized by six domains (attention, working memory, visual memory, executive function, visuospatial function, and global cognition). Partial correlations and multivariate linear regression were used to determine independent associations for all participants and for PD tremor-dominant (TD) and postural instability and gait disorder (PIGD) phenotypes, controlling for age, sex, and premorbid intelligence using the national adult reading test. Cognitive and gait outcomes were significantly worse for PD. Gait, but not cognitive outcomes, was selectively worse for the PIGD phenotype compared with TD. Significant associations emerged for two gait domains for controls (pace and postural control) and four gait domains for PD (pace, rhythm, variability, and postural control). The strongest correlation was for pace and attention for PD and controls. Associations were not significant for participants with the TD phenotype. In early PD, the cognitive correlates of gait are predominantly with fronto-executive functions, and are characterized by the PIGD PD phenotype. These associations provide a basis for understanding the complex role of cognition in parkinsonian gait. PMID:25374538

  7. Characteristic muscle activity patterns during gait initiation in the healthy younger and older adults.

    PubMed

    Khanmohammadi, Roya; Talebian, Saeed; Hadian, Mohammad Reza; Olyaei, Gholamreza; Bagheri, Hossein

    2016-01-01

    It is thought that gait initiation (GI) might be an optimal task for identifying postural control deficiencies. Thus, the aim of this study was to clarify the strategies adopted by older subjects during this task. 16 healthy younger and 15 healthy older adults participated in the study. Subjects were instructed to begin forward stepping with their dominant limb in response to an auditory stimulus. The mean muscle activity, co-contraction index, and intra-subject coefficients of variation (intra-subject CVs) of dominant limb muscles in different phases of GI were measured. The level of association between the co-contraction index and intra-subject CV of muscles was also explored. This study showed that in the anticipatory phase, the younger group had larger amplitudes and more intra-subject CVs than older the group, particularly for the tibialis anterior muscle. However, the co-contraction index was greater in older subjects relative to younger subjects. During the weight transition phase, tibialis anterior, semitendinosus and vastus lateralis muscles of older adults had a lower amplitude as compared to younger adults. However, during the locomotor phase, the activity of tibialis anterior was greater in comparison to younger adults. Also, during this phase, similar to the anticipatory phase, the co-contraction index between tibialis anterior and gastrocnemius muscles was greater in older subjects relative to younger subjects. Additionally, the larger co-contraction index of some muscles was associated with smaller intra-subject CV. These findings suggest that muscle behaviors are altered with aging and older adults employ different strategies in the different phases of GI as compared to younger adults.

  8. The gait pattern is not impaired in subjects with external snapping hip: a comparative cross-sectional study

    PubMed Central

    2013-01-01

    Background Symptomatic external snapping hip is a painful condition, where pain in the trochantor region and limitations of daily activity dominate clinical findings. The aetiology of symptomatic external snapping hip is elusive, but previous studies have suggested that weakness of the hip abductors and an altered walking pattern may play a role in the development of symptomatic external snapping hip. The aim of this study was to compare the walking pattern and muscular activity of the hip muscles between subjects with symptomatic external snapping hip and healthy subjects. Methods Thirteen subjects with diagnosed symptomatic external snapping hip (age: 25.5 years) were matched with 13 healthy subjects (age: 25.6 years). Joint kinematics and kinetics of the lower extremity were quantified by the peak hip adduction angle; the average knee rotation range of motion (ROM) and the peak valgus knee angle after data recording using a Vicon 612 motion capture system. Muscle activity was recorded bilaterally using surface electromyography (sEMG) on five muscles: gluteus maximus, gluteus medius, tensor fascia latae, rectus femoris and biceps femoris. A paired t-test was used to evaluate differences between the two groups. Results No significant differences were found between the groups concerning the peak hip adduction angle, the average knee rotation ROM, and the static valgus knee angle. No significant between-group differences were found concerning all other kinematics, kinetics or muscle activity. In subjects with symptomatic external snapping hip activity of the gluteus medius muscle during the acceptance phase of walking was 0.58 ± 0.19 whereas the activity was 0.68±0.07 in the asymptomatic group (p=0.115). Conclusions No significant differences in the walking pattern were found between subjects with symptomatic external snapping hip and healthy subjects. This suggest that subjects with symptomatic external snapping hip does not have an impaired gait pattern. PMID

  9. Gait pattern of heifers before and after claw trimming: a high-speed cinematographic study on a treadmill.

    PubMed

    Meyer, S W; Weishaupt, M A; Nuss, K A

    2007-02-01

    The manner in which the claws contacted the ground at the walk was evaluated in 18 healthy heifers. The animals were filmed before and after claw trimming while walking on a treadmill using high-speed cinematography (500 frames/s). For each limb, 4 consecutive steps were recorded from a side and a frontal plane. The objectives of the study were to evaluate 1) the order of claw contact with the treadmill surface, 2) the initial claw contact area, and 3) the effect of trimming on claw contact patterns. The heifers placed their front feet on the ground in a plane sagittal to the shoulders, whereas the hind feet were advanced more toward the median plane. Before trimming, the lateral claws contacted the ground before the medial in 83% of front and 100% of hind limbs. Trimming changed the percentage to 92% in the front and to 97% in the hind limbs. The percentage with which the heel of the lateral claws became the region of initial contact with the ground increased from 47 to 64% in the front feet and from 50 to 78% in the hind feet. In the medial claws of the forelimbs, claw trimming shifted the region of initial contact from the toe to the abaxial wall and heel. In the hind limbs, the main region of initial contact of the medial claws became the abaxial wall. Weight bearing by the medial claw became visibly apparent only during the midstance, propulsion, and push-off phases. "Heel first" contact of the lateral claws in the front and hind limbs may be the normal gait pattern in cattle. On hard surfaces, this pattern may lead to overload and predispose to disease, especially in the hind limbs. PMID:17235142

  10. Teachers' knowledge of normal and abnormal elimination patterns in elementary school children.

    PubMed

    Boyt, Margaret A

    2005-12-01

    Dysfunctional elimination may be learned, to some degree. Because children spend nearly half of their waking hours at school, there is the potential for school to have a significant impact on their elimination patterns. Surveys were mailed to 1,000 randomly selected Iowa public elementary school teachers; 467 of the surveys were returned. Findings indicate that most elementary school teachers are unaware of the potential health problems of elimination dysfunction. One third of respondents indicated that they ask children to wait to go to the bathroom. Suboptimal conditions exist in most of the school bathrooms, with only 35% of the boys' restrooms and 48% of the girls' restrooms reported as "always clean." Those teachers with more experience were more likely to report information about abnormal elimination to the school nurse. Very few teachers (18% of respondents) reported having received information about abnormal elimination and even fewer (8% of respondents) were aware of specialists trained to treat children with these problems. School nurses can have a significant impact on the development of healthy bladder habits in children. Teachers need information about normal and abnormal elimination patterns in children. PMID:16285844

  11. Human gait recognition via deterministic learning.

    PubMed

    Zeng, Wei; Wang, Cong

    2012-11-01

    Recognition of temporal/dynamical patterns is among the most difficult pattern recognition tasks. Human gait recognition is a typical difficulty in the area of dynamical pattern recognition. It classifies and identifies individuals by their time-varying gait signature data. Recently, a new dynamical pattern recognition method based on deterministic learning theory was presented, in which a time-varying dynamical pattern can be effectively represented in a time-invariant manner and can be rapidly recognized. In this paper, we present a new model-based approach for human gait recognition via the aforementioned method, specifically for recognizing people by gait. The approach consists of two phases: a training (learning) phase and a test (recognition) phase. In the training phase, side silhouette lower limb joint angles and angular velocities are selected as gait features. A five-link biped model for human gait locomotion is employed to demonstrate that functions containing joint angle and angular velocity state vectors characterize the gait system dynamics. Due to the quasi-periodic and symmetrical characteristics of human gait, the gait system dynamics can be simplified to be described by functions of joint angles and angular velocities of one side of the human body, thus the feature dimension is effectively reduced. Locally-accurate identification of the gait system dynamics is achieved by using radial basis function (RBF) neural networks (NNs) through deterministic learning. The obtained knowledge of the approximated gait system dynamics is stored in constant RBF networks. A gait signature is then derived from the extracted gait system dynamics along the phase portrait of joint angles versus angular velocities. A bank of estimators is constructed using constant RBF networks to represent the training gait patterns. In the test phase, by comparing the set of estimators with the test gait pattern, a set of recognition errors are generated, and the average L(1) norms

  12. Abnormal Brain Connectivity Patterns in Adults with ADHD: A Coherence Study

    PubMed Central

    Sato, João Ricardo; Hoexter, Marcelo Queiroz; Castellanos, Xavier Francisco; Rohde, Luis A.

    2012-01-01

    Studies based on functional magnetic resonance imaging (fMRI) during the resting state have shown decreased functional connectivity between the dorsal anterior cingulate cortex (dACC) and regions of the Default Mode Network (DMN) in adult patients with Attention-Deficit/Hyperactivity Disorder (ADHD) relative to subjects with typical development (TD). Most studies used Pearson correlation coefficients among the BOLD signals from different brain regions to quantify functional connectivity. Since the Pearson correlation analysis only provides a limited description of functional connectivity, we investigated functional connectivity between the dACC and the posterior cingulate cortex (PCC) in three groups (adult patients with ADHD, n = 21; TD age-matched subjects, n = 21; young TD subjects, n = 21) using a more comprehensive analytical approach – unsupervised machine learning using a one-class support vector machine (OC-SVM) that quantifies an abnormality index for each individual. The median abnormality index for patients with ADHD was greater than for TD age-matched subjects (p = 0.014); the ADHD and young TD indices did not differ significantly (p = 0.480); the median abnormality index of young TD was greater than that of TD age-matched subjects (p = 0.016). Low frequencies below 0.05 Hz and around 0.20 Hz were the most relevant for discriminating between ADHD patients and TD age-matched controls and between the older and younger TD subjects. In addition, we validated our approach using the fMRI data of children publicly released by the ADHD-200 Competition, obtaining similar results. Our findings suggest that the abnormal coherence patterns observed in patients with ADHD in this study resemble the patterns observed in young typically developing subjects, which reinforces the hypothesis that ADHD is associated with brain maturation deficits. PMID:23049834

  13. Muscle-skeletal model of the thigh: a tool for understanding the biomechanics of gait in patients with cerebral palsy

    NASA Astrophysics Data System (ADS)

    Ravera, Emiliano Pablo; Catalfamo Formento, Paola Andrea; José Crespo, Marcos; Andrés Braidot, Ariel

    2011-12-01

    Cerebral Palsy represents the most common cause of physical disability in modern world and within the pediatrics orthopedics units. The gait analysis provides great contributions to the understanding of gait disorders in CP. Giving a more comprehensive treatment plan, including or excluding surgical procedures that can potentially decrease the number of surgical interventions in the life of these patients. Recommendations for orthopedic surgery may be based on a quantitative description of how to alter the properties probably muscle force generation, and how this affects the action of the muscle to determine how these muscles, impaired by disease or surgery, contributing to the movement of the segments of the limb during crouch gait. So the causes and appropriate treatment of gait abnormalities are difficult to determine because the movements generated by the muscular forces of these patients are not clearly understood. A correct determination of the etiology of abnormal patterns of the knee is the key to select the appropriate therapy, presenting a major challenge at present since there is no theoretical basis to determine the biomechanical causes of abnormal gait of these patients. The potential and necessity of using correct biomechanical models that consistently study the abnormalities becomes clear. Reinforcing and correcting a simple gait analysis and eliminating the unknowns when selecting the appropriate treatment is crucial in clinical settings. In this paper a computer muscle-skeletal model is proposed. The model represents a person's thigh simulating the six most representative muscles and joints of the hip and knee. In this way you can have a better understanding of gait abnormalities present in these patients. So the quality of these estimates of individual muscle dynamics facilitate better understanding of the biomechanics of gait pathologies helping to reach better diagnosis prior to surgery and rehabilitation treatments.

  14. Context based gait recognition

    NASA Astrophysics Data System (ADS)

    Bazazian, Shermin; Gavrilova, Marina

    2012-06-01

    Gait recognition has recently become a popular topic in the field of biometrics. However, the main hurdle is the insufficient recognition rate in the presence of low quality samples. The main focus of this paper is to investigate how the performance of a gait recognition system can be improved using additional information about behavioral patterns of users and the context in which samples have been taken. The obtained results show combining the context information with biometric data improves the performance of the system at a very low cost. The amount of improvement depends on the distinctiveness of the behavioral patterns and the quality of the gait samples. Using the appropriate distinctive behavioral models it is possible to achieve a 100% recognition rate.

  15. Neural code alterations and abnormal time patterns in Parkinson’s disease

    NASA Astrophysics Data System (ADS)

    Andres, Daniela Sabrina; Cerquetti, Daniel; Merello, Marcelo

    2015-04-01

    Objective. The neural code used by the basal ganglia is a current question in neuroscience, relevant for the understanding of the pathophysiology of Parkinson’s disease. While a rate code is known to participate in the communication between the basal ganglia and the motor thalamus/cortex, different lines of evidence have also favored the presence of complex time patterns in the discharge of the basal ganglia. To gain insight into the way the basal ganglia code information, we studied the activity of the globus pallidus pars interna (GPi), an output node of the circuit. Approach. We implemented the 6-hydroxydopamine model of Parkinsonism in Sprague-Dawley rats, and recorded the spontaneous discharge of single GPi neurons, in head-restrained conditions at full alertness. Analyzing the temporal structure function, we looked for characteristic scales in the neuronal discharge of the GPi. Main results. At a low-scale, we observed the presence of dynamic processes, which allow the transmission of time patterns. Conversely, at a middle-scale, stochastic processes force the use of a rate code. Regarding the time patterns transmitted, we measured the word length and found that it is increased in Parkinson’s disease. Furthermore, it showed a positive correlation with the frequency of discharge, indicating that an exacerbation of this abnormal time pattern length can be expected, as the dopamine depletion progresses. Significance. We conclude that a rate code and a time pattern code can co-exist in the basal ganglia at different temporal scales. However, their normal balance is progressively altered and replaced by pathological time patterns in Parkinson’s disease.

  16. Are clinical parameters sufficient to model gait patterns in patients with cerebral palsy using a multilinear approach?

    PubMed

    Bonnefoy-Mazure, Alice; Sagawa, Yoshisama; Pomero, Vincent; Lascombes, Pierre; De Coulon, Geraldo; Armand, Stéphane

    2016-01-01

    The aim of this study was to evaluate whether clinical parameters are sufficient using, a multilinear regression model, to reproduce the sagittal plane joint angles (hip, knee, and ankle) in cerebral palsy gait. A total of 154 patients were included. The two legs were considered (308 observations). Thirty-six clinical parameters were used as regressors (range of motion, muscle strength, and spasticity of the lower). From the clinical gait analysis, the joint angles of the sagittal plane were selected. Results showed that clinical parameter does not provide sufficient information to recover joint angles and/or that the multilinear regression model is not an appropriate solution.

  17. Abnormal methylation pattern in constitutive and facultative heterochromatin of ICF patients

    SciTech Connect

    Miniou, P.; Blanquet, V.; Viegas-Pequignot, E.

    1994-09-01

    ICF syndrome is a rare autosomal recessive disease, characterized by variable immunodeficiency, centromeric instability and facial abnormalities. Stretchings and frequent associations of centromeric or juxtacentromeric heterochromatin of chromosome 1 and 16 principally, and to a lesser degree, chromosome 9 mimic chromosome features of normal PHA-stimulated lymphocytes treated with 5-azacytidine, an inducer of demethylation. In fact, in these patients we have detected by DNA digestion with methyl-sensitive enzymes a hypomethylation of classical satellites 2 and 3, located in heterochromatin. To assess the role of other satellite DNA in the heterochromatin modifications and chromosome rearrangements, in situ fluorescent method using 5-methylcytosine (5-MeC) monoclonal antibody on chromosomes and nuclei were performed in parallel with Southern blot analysis of other satellite sequences located in heterochromatin. 5-MeC reveals that constitutive and facultative heterochromatin (X inactive chromosome) are hypomethylated. Alpha satellite sequences corresponding to centromeric heterochromatin of chromosomes 1, 3, 6, 9, 16, 18 and X are mostly methylated in patients G and R, and are undermethylated in patient S. Both molecular and cytogenetic analysis are in agreement. By in situ hybridization, breakpoints of rearranged chromosomes were located in stretched and hypomethylated classical satellites. In euchromatin, 5-MeC antibodies reveal an R-like banding pattern indicating an unequal distribution of DNA methylation, disclosing another aspect of chromosome organization. The underlying hypomethylation, associated with an abnormal chromatin structure, may predispose to chromosome instability.

  18. Abnormal changes of multidimensional surface features using multivariate pattern classification in amnestic mild cognitive impairment patients.

    PubMed

    Li, Shuyu; Yuan, Xiankun; Pu, Fang; Li, Deyu; Fan, Yubo; Wu, Liyong; Chao, Wang; Chen, Nan; He, Yong; Han, Ying

    2014-08-01

    Previous studies have suggested that amnestic mild cognitive impairment (aMCI) is associated with changes in cortical morphological features, such as cortical thickness, sulcal depth, surface area, gray matter volume, metric distortion, and mean curvature. These features have been proven to have specific neuropathological and genetic underpinnings. However, most studies primarily focused on mass-univariate methods, and cortical features were generally explored in isolation. Here, we used a multivariate method to characterize the complex and subtle structural changing pattern of cortical anatomy in 24 aMCI human participants and 26 normal human controls. Six cortical features were extracted for each participant, and the spatial patterns of brain abnormities in aMCI were identified by high classification weights using a support vector machine method. The classification accuracy in discriminating the two groups was 76% in the left hemisphere and 80% in the right hemisphere when all six cortical features were used. Regions showing high weights were subtle, spatially complex, and predominately located in the left medial temporal lobe and the supramarginal and right inferior parietal lobes. In addition, we also found that the six morphological features had different contributions in discriminating the two groups even for the same region. Our results indicated that the neuroanatomical patterns that discriminated individuals with aMCI from controls were truly multidimensional and had different effects on the morphological features. Furthermore, the regions identified by our method could potentially be useful for clinical diagnosis. PMID:25100588

  19. Accurate means of detecting and characterizing abnormal patterns of ventricular activation by phase image analysis

    SciTech Connect

    Botvinick, E.H.; Frais, M.A.; Shosa, D.W.; O'Connell, J.W.; Pacheco-Alvarez, J.A.; Scheinman, M.; Hattner, R.S.; Morady, F.; Faulkner, D.B.

    1982-08-01

    The ability of scintigraphic phase image analysis to characterize patterns of abnormal ventricular activation was investigated. The pattern of phase distribution and sequential phase changes over both right and left ventricular regions of interest were evaluated in 16 patients with normal electrical activation and wall motion and compared with those in 8 patients with an artificial pacemaker and 4 patients with sinus rhythm with the Wolff-Parkinson-White syndrome and delta waves. Normally, the site of earliest phase angle was seen at the base of the interventricular septum, with sequential change affecting the body of the septum and the cardiac apex and then spreading laterally to involve the body of both ventricles. The site of earliest phase angle was located at the apex of the right ventricle in seven patients with a right ventricular endocardial pacemaker and on the lateral left ventricular wall in one patient with a left ventricular epicardial pacemaker. In each case the site corresponded exactly to the position of the pacing electrode as seen on posteroanterior and left lateral chest X-ray films, and sequential phase changes spread from the initial focus to affect both ventricles. In each of the patients with the Wolff-Parkinson-White syndrome, the site of earliest ventricular phase angle was located, and it corresponded exactly to the site of the bypass tract as determined by endocardial mapping. In this way, four bypass pathways, two posterior left paraseptal, one left lateral and one right lateral, were correctly localized scintigraphically. On the basis of the sequence of mechanical contraction, phase image analysis provides an accurate noninvasive method of detecting abnormal foci of ventricular activation.

  20. Exhaled Aerosol Pattern Discloses Lung Structural Abnormality: A Sensitivity Study Using Computational Modeling and Fractal Analysis

    PubMed Central

    Xi, Jinxiang; Si, Xiuhua A.; Kim, JongWon; Mckee, Edward; Lin, En-Bing

    2014-01-01

    Background Exhaled aerosol patterns, also called aerosol fingerprints, provide clues to the health of the lung and can be used to detect disease-modified airway structures. The key is how to decode the exhaled aerosol fingerprints and retrieve the lung structural information for a non-invasive identification of respiratory diseases. Objective and Methods In this study, a CFD-fractal analysis method was developed to quantify exhaled aerosol fingerprints and applied it to one benign and three malign conditions: a tracheal carina tumor, a bronchial tumor, and asthma. Respirations of tracer aerosols of 1 µm at a flow rate of 30 L/min were simulated, with exhaled distributions recorded at the mouth. Large eddy simulations and a Lagrangian tracking approach were used to simulate respiratory airflows and aerosol dynamics. Aerosol morphometric measures such as concentration disparity, spatial distributions, and fractal analysis were applied to distinguish various exhaled aerosol patterns. Findings Utilizing physiology-based modeling, we demonstrated substantial differences in exhaled aerosol distributions among normal and pathological airways, which were suggestive of the disease location and extent. With fractal analysis, we also demonstrated that exhaled aerosol patterns exhibited fractal behavior in both the entire image and selected regions of interest. Each exhaled aerosol fingerprint exhibited distinct pattern parameters such as spatial probability, fractal dimension, lacunarity, and multifractal spectrum. Furthermore, a correlation of the diseased location and exhaled aerosol spatial distribution was established for asthma. Conclusion Aerosol-fingerprint-based breath tests disclose clues about the site and severity of lung diseases and appear to be sensitive enough to be a practical tool for diagnosis and prognosis of respiratory diseases with structural abnormalities. PMID:25105680

  1. Effects of acceleration on gait measures in three horse gaits.

    PubMed

    Nauwelaerts, Sandra; Zarski, Lila; Aerts, Peter; Clayton, Hilary

    2015-05-01

    Animals switch gaits according to locomotor speed. In terrestrial locomotion, gaits have been defined according to footfall patterns or differences in center of mass (COM) motion, which characterizes mechanisms that are more general and more predictive than footfall patterns. This has generated different variables designed primarily to evaluate steady-speed locomotion, which is easier to standardize in laboratory conditions. However, in the ecology of an animal, steady-state conditions are rare and the ability to accelerate, decelerate and turn is essential. Currently, there are no data available that have tested whether COM variables can be used in accelerative or decelerative conditions. This study used a data set of kinematics and kinetics of horses using three gaits (walk, trot, canter) to evaluate the effects of acceleration (both positive and negative) on commonly used gait descriptors. The goal was to identify variables that distinguish between gaits both at steady state and during acceleration/deceleration. These variables will either be unaffected by acceleration or affected by it in a predictable way. Congruity, phase shift and COM velocity angle did not distinguish between gaits when the dataset included trials in unsteady conditions. Work (positive and negative) and energy recovery distinguished between gaits and showed a clear relationship with acceleration. Hodographs are interesting graphical representations to study COM mechanics, but they are descriptive rather than quantitative. Force angle, collision angle and collision fraction showed a U-shaped relationship with acceleration and seem promising tools for future research in unsteady conditions.

  2. Methods to temporally align gait cycle data.

    PubMed

    Helwig, Nathaniel E; Hong, Sungjin; Hsiao-Wecksler, Elizabeth T; Polk, John D

    2011-02-01

    The need for the temporal alignment of gait cycle data is well known; however, there is little consensus concerning which alignment method to use. In this paper, we discuss the pros and cons of some methods commonly applied to temporally align gait cycle data (normalization to percent gait cycle, dynamic time warping, derivative dynamic time warping, and piecewise alignment methods). In addition, we empirically evaluate these different methods' abilities to produce successful temporal alignment when mapping a test gait cycle trajectory to a target trajectory. We demonstrate that piecewise temporal alignment techniques outperform other commonly used alignment methods (normalization to percent gait cycle, dynamic time warping, and derivative dynamic time warping) in typical biomechanical and clinical alignment tasks. Lastly, we present an example of how these piecewise alignment techniques make it possible to separately examine intensity and temporal differences between gait cycle data throughout the entire gait cycle, which can provide greater insight into the complexities of movement patterns.

  3. Accelerometry reveals differences in gait variability between patients with multiple sclerosis and healthy controls.

    PubMed

    Huisinga, Jessie M; Mancini, Martina; St George, Rebecca J; Horak, Fay B

    2013-08-01

    Variability of movement reflects important information for the maintenance of the health of the system. For pathological populations, changes in variability during gait signal the presence of abnormal motor control strategies. For persons with multiple sclerosis (PwMS), extensive gait problems have been reported including changes in gait variability. While previous studies have focused on footfall variability, the present study used accelerometers on the trunk to measure variability during walking. Thus, the purpose of this study was to examine the variability of the acceleration pattern of the upper and lower trunk in PwMS compared to healthy controls. We extracted linear and nonlinear measures of gait variability from 30 s of steady state walking for 15 PwMS and 15 age-matched healthy controls. PwMS had altered variability compared to controls with greater Lyapunov exponent in the ML (p < 0.001) and AP (p < 0.001) directions, and greater frequency dispersion in the ML direction (p = 0.034). PwMS also demonstrated greater mean velocity in the ML direction (p = 0.045) and lower root mean square of acceleration in the AP direction (p = 0.040). These findings indicate that PwMS have altered structure of variability of the trunk during gait compared to healthy controls and agree with previous findings related to changes in gait variability in PwMS.

  4. Segmentation and classification of gait cycles.

    PubMed

    Agostini, Valentina; Balestra, Gabriella; Knaflitz, Marco

    2014-09-01

    Gait abnormalities can be studied by means of instrumented gait analysis. Foot-switches are useful to study the foot-floor contact and for timing the gait phases in many gait disorders, provided that a reliable foot-switch signal may be collected. Considering long walks allows reducing the intra-subject variability, but requires automatic and user-independent methods to analyze a large number of gait cycles. The aim of this work is to describe and validate an algorithm for the segmentation of the foot-switch signal and the classification of the gait cycles. The performance of the algorithm was assessed comparing its results against the manual segmentation and classification performed by a gait analysis expert on the same signal. The performance was found to be equal to 100% for healthy subjects and over 98% for pathological subjects. The algorithm allows determining the atypical cycles (cycles that do not match the standard sequence of gait phases) for many different kinds of pathological gait, since it is not based on pathology-specific templates.

  5. Modeling and simulation of normal and hemiparetic gait

    NASA Astrophysics Data System (ADS)

    Luengas, Lely A.; Camargo, Esperanza; Sanchez, Giovanni

    2015-09-01

    Gait is the collective term for the two types of bipedal locomotion, walking and running. This paper is focused on walking. The analysis of human gait is of interest to many different disciplines, including biomechanics, human-movement science, rehabilitation and medicine in general. Here we present a new model that is capable of reproducing the properties of walking, normal and pathological. The aim of this paper is to establish the biomechanical principles that underlie human walking by using Lagrange method. The constraint forces of Rayleigh dissipation function, through which to consider the effect on the tissues in the gait, are included. Depending on the value of the factor present in the Rayleigh dissipation function, both normal and pathological gait can be simulated. First of all, we apply it in the normal gait and then in the permanent hemiparetic gait. Anthropometric data of adult person are used by simulation, and it is possible to use anthropometric data for children but is necessary to consider existing table of anthropometric data. Validation of these models includes simulations of passive dynamic gait that walk on level ground. The dynamic walking approach provides a new perspective of gait analysis, focusing on the kinematics and kinetics of gait. There have been studies and simulations to show normal human gait, but few of them have focused on abnormal, especially hemiparetic gait. Quantitative comparisons of the model predictions with gait measurements show that the model can reproduce the significant characteristics of normal gait.

  6. Acoustic Gaits: Gait Analysis With Footstep Sounds.

    PubMed

    Altaf, M Umair Bin; Butko, Taras; Juang, Biing-Hwang Fred

    2015-08-01

    We describe the acoustic gaits-the natural human gait quantitative characteristics derived from the sound of footsteps as the person walks normally. We introduce the acoustic gait profile, which is obtained from temporal signal analysis of sound of footsteps collected by microphones and illustrate some of the spatio-temporal gait parameters that can be extracted from the acoustic gait profile by using three temporal signal analysis methods-the squared energy estimate, Hilbert transform and Teager-Kaiser energy operator. Based on the statistical analysis of the parameter estimates, we show that the spatio-temporal parameters and gait characteristics obtained using the acoustic gait profile can consistently and reliably estimate a subset of clinical and biometric gait parameters currently in use for standardized gait assessments. We conclude that the Teager-Kaiser energy operator provides the most consistent gait parameter estimates showing the least variation across different sessions and zones. Acoustic gaits use an inexpensive set of microphones with a computing device as an accurate and unintrusive gait analysis system. This is in contrast to the expensive and intrusive systems currently used in laboratory gait analysis such as the force plates, pressure mats and wearable sensors, some of which may change the gait parameters that are being measured.

  7. Relationship between muscle impairments, postural stability, and gait parameters assessed with lower-trunk accelerometry in myotonic dystrophy type 1.

    PubMed

    Bachasson, Damien; Moraux, Amélie; Ollivier, Gwenn; Decostre, Valérie; Ledoux, Isabelle; Gidaro, Teresa; Servais, Laurent; Behin, Anthony; Stojkovic, Tanya; Hébert, Luc J; Puymirat, Jack; Eymard, Bruno; Bassez, Guillaume; Hogrel, Jean-Yves

    2016-07-01

    This study evaluated gait using lower-trunk accelerometry and investigated relationships between gait abnormalities, postural instability, handgrip myotonia, and weakness in lower-limb and axial muscle groups commonly affected in myotonic dystrophy type 1 (DM1). Twenty-two patients (11 men, 11 women; age = 42 years (range: 26-51)) with DM1 and twenty healthy controls (9 men, 11 women; age = 44 years (range: 24-50)) participated in this study. Gait analysis using lower-trunk accelerometry was performed at self-selected walking pace. Postural stability was measured via center of pressure displacement analysis using a force platform during eyes-closed normal stance. Handgrip myotonia was quantified using force-relaxation curve modeling. Patients displayed lower walking speed, stride frequency, stride length, gait regularity, and gait symmetry. Strength of ankle plantar flexors, ankle dorsal flexors and neck flexors correlated with interstride regularity in the vertical direction (ρ = 0.57, ρ = 0.59, and ρ = 0.44, respectively; all P < 0.05). Knee extension strength correlated with gait symmetry in the anteroposterior direction (ρ = 0.45, P < 0.05). Center of pressure velocity was greater in patients and correlated with neck flexion and ankle plantar flexion weakness (ρ = -0.51 and ρ = -0.62, respectively; both P < 0.05), and with interstride regularity in the vertical direction (ρ = -0.58, P < 0.05). No correlation was found between handgrip myotonia and any other variable studied. Lower-trunk accelerometry allows the characterization of gait pattern abnormalities in patients with DM1. Further studies are required to determine the relevance of systematic gait analysis using lower-trunk accelerometry for patient follow-up and intervention planning. PMID:27234310

  8. Genetic feature selection for gait recognition

    NASA Astrophysics Data System (ADS)

    Tafazzoli, Faezeh; Bebis, George; Louis, Sushil; Hussain, Muhammad

    2015-01-01

    Many research studies have demonstrated that gait can serve as a useful biometric modality for human identification at a distance. Traditional gait recognition systems, however, have mostly been evaluated without explicitly considering the most relevant gait features, which might have compromised performance. We investigate the problem of selecting a subset of the most relevant gait features for improving gait recognition performance. This is achieved by discarding redundant and irrelevant gait features while preserving the most informative ones. Motivated by our previous work on feature subset selection using genetic algorithms (GAs), we propose using GAs to select an optimal subset of gait features. First, features are extracted using kernel principal component analysis (KPCA) on spatiotemporal projections of gait silhouettes. Then, GA is applied to select a subset of eigenvectors in KPCA space that best represents a subject's identity. Each gait pattern is then represented by projecting it only on the eigenvectors selected by the GA. To evaluate the effectiveness of the selected features, we have experimented with two different classifiers: k nearest-neighbor and Naïve Bayes classifier. We report considerable gait recognition performance improvements on the Georgia Tech and CASIA databases.

  9. Gait disturbances in dystrophic hamsters.

    PubMed

    Hampton, Thomas G; Kale, Ajit; Amende, Ivo; Tang, Wenlong; McCue, Scott; Bhagavan, Hemmi N; VanDongen, Case G

    2011-01-01

    The delta-sarcoglycan-deficient hamster is an excellent model to study muscular dystrophy. Gait disturbances, important clinically, have not been described in this animal model. We applied ventral plane videography (DigiGait) to analyze gait in BIO TO-2 dystrophic and BIO F1B control hamsters walking on a transparent treadmill belt. Stride length was ∼13% shorter (P < .05) in TO-2 hamsters at 9 months of age compared to F1B hamsters. Hindlimb propulsion duration, an indicator of muscle strength, was shorter in 9-month-old TO-2 (247 ± 8 ms) compared to F1B hamsters (272 ± 11 ms; P < .05). Braking duration, reflecting generation of ground reaction forces, was delayed in 9-month-old TO-2 (147 ± 6 ms) compared to F1B hamsters (126 ± 8 ms; P < .05). Hindpaw eversion, evidence of muscle weakness, was greater in 9-month-old TO-2 than in F1B hamsters (17.7 ± 1.2° versus 8.7 ± 1.6°; P < .05). Incline and decline walking aggravated gait disturbances in TO-2 hamsters at 3 months of age. Several gait deficits were apparent in TO-2 hamsters at 1 month of age. Quantitative gait analysis demonstrates that dystrophic TO-2 hamsters recapitulate functional aspects of human muscular dystrophy. Early detection of gait abnormalities in a convenient animal model may accelerate the development of therapies for muscular dystrophy.

  10. Classification of abnormal fundus autofluorescence patterns in the junctional zone of geographic atrophy in patients with age related macular degeneration

    PubMed Central

    Bindewald, A; Schmitz-Valckenberg, S; Jorzik, J J; Dolar-Szczasny, J; Sieber, H; Keilhauer, C; Weinberger, A W A; Dithmar, S; Pauleikhoff, D; Mansmann, U; Wolf, S; Holz, F G

    2005-01-01

    Aim: To describe and classify patterns of abnormal fundus autofluorescence (FAF) in the junctional zone of geographic atrophy (GA) in patients with age related macular degeneration. Methods: Digital FAF images were recorded in 164 eyes of 107 patients using a confocal scanning laser ophthalmoscope (cSLO; excitation 488 nm, detection above 500 nm) as part of a prospective multicentre natural history study (FAM Study). FAF images were obtained in accordance with a standardised protocol for digital image acquisition and generation of mean images after automated alignment. Results: Image quality was sufficient for classification of FAF patterns in 149 eyes (90.9%) with lens opacities being the most common reason for insufficient image quality. Abnormal FAF outside GA in 149 eyes was classified into four patterns: focal (12.1%), banded (12.8%), patchy (2.0%), and diffuse (57.0%), whereby 12.1% had normal background FAF in the junctional zone. In 4% there was no predominant pattern. The diffuse pattern was subdivided into four groups including reticular (4.7%), branching (27.5%), fine granular (18.1%), and fine granular with peripheral punctate spots (6.7%). Conclusions: Different phenotypic patterns of abnormal FAF in the junctional zone of GA can be identified with cSLO FAF imaging. These distinct patterns may reflect heterogeneity at a cellular and molecular level in contrast with a non-specific ageing process. A refined phenotypic classification may be helpful to identify prognostic determinants for the spread of atrophy and visual loss, for identification of genetic risk factors as well as for the design of future interventional trials. PMID:15965170

  11. A spatiotemporal mining framework for abnormal association patterns in marine environments with a time series of remote sensing images

    NASA Astrophysics Data System (ADS)

    Xue, Cunjin; Song, Wanjiao; Qin, Lijuan; Dong, Qing; Wen, Xiaoyang

    2015-06-01

    A spatiotemporal mining framework is a novel tool for the analysis of marine association patterns using multiple remote sensing images. From data pretreatment, to algorithm design, to association rule mining and pattern visualization, this paper outlines a spatiotemporal mining framework for abnormal association patterns in marine environments, including pixel-based and object-based mining models. Within this framework, some key issues are also addressed. In the data pretreatment phase, we propose an algorithm for extracting abnormal objects or pixels over marine surfaces, and construct a mining transaction table with object-based and pixel-based strategies. In the mining algorithm phase, a recursion method to construct a direct association pattern tree is addressed with an asymmetric mutual information table, and a recursive mining algorithm to find frequent items. In the knowledge visualization phase, a "Dimension-Attributes" visualization framework is used to display spatiotemporal association patterns. Finally, spatiotemporal association patterns for marine environmental parameters in the Pacific Ocean are identified, and the results prove the effectiveness and the efficiency of the proposed mining framework.

  12. Periodical gait asymmetry assessment using real-time wireless gyroscopes gait monitoring system.

    PubMed

    Gouwanda, D; Senanayake, S M N A

    2011-11-01

    A real-time gait monitoring system that incorporates an immediate and periodical assessment of gait asymmetry is described. This system was designed for gait analysis and rehabilitation of patients with pathologic gait. It employs wireless gyroscopes to measure the angular rate of the thigh and shank in real time. Cross-correlation of the lower extremity (Cc(norm)), and normalized Symmetry Index (SI(norm)) are implemented as new approaches to periodically determine the gait asymmetry in each gait cycle. Cc(norm) evaluates the signal patterns measured by wireless gyroscopes in each gait cycle. SI(norm) determines the movement differences between the left and right limb. An experimental study was conducted to examine the viability of these methods. Artificial asymmetrical gait was simulated by placing a load on one side of the limbs. Results showed that there were significant differences between the normal gait and asymmetrical gait (p < 0.01). They also indicated that the system worked well in periodically assessing the gait asymmetry.

  13. Frequency and patterns of abnormality detected by iodine-123 amine emission CT after cerebral infarction

    SciTech Connect

    Brott, T.G.; Gelfand, M.J.; Williams, C.C.; Spilker, J.A.; Hertzberg, V.S.

    1986-03-01

    Single photon emission computed tomography (SPECT) was performed in 31 patients with cerebral infarction and 13 who had had transient ischemic attacks, using iodine-123-labeled N,N,N'-trimethyl-N'-(2-hydroxyl-3-methyl-5-iodobenzyl)-1,3-propanediamin e (I-123-HIPDM) as the radiopharmaceutical. SPECT scans were compared with computed tomographic (CT) scans. SPECT was as sensitive as CT in detecting cerebral infarction (94% vs. 84%). The abnormalities were larger on the SPECT scans than on the CT scans in 19 cases, equal in seven, and smaller in five (SPECT abnormalities greater than or equal to CT abnormalities in 86% of cases). Fifteen of 30 patients with hemispheric infarction had decreased perfusion (decreased uptake of I-123-HIPDM) to the cerebellar hemisphere contralateral to the cerebral hemisphere involved by the infarction (crossed cerebellar diaschisis). Nine of these 15 patients had major motor deficits, while only one of the 15 without crossed cerebellar diaschisis had a major motor deficit.

  14. Spreading Photoparoxysmal EEG Response is Associated with an Abnormal Cortical Excitability Pattern

    ERIC Educational Resources Information Center

    Siniatchkin, Michael; Groppa, Sergey; Jerosch, Bettina; Muhle, Hiltrud; Kurth, Christoph; Shepherd, Alex J.; Siebner, Hartwig; Stephani, Ulrich

    2007-01-01

    Photosensitivity or photoparoxysmal response (PPR) is a highly heritable electroencephalographic trait characterized by an abnormal cortical response to intermittent photic stimulation (IPS). In PPR-positive individuals, IPS induces spikes, spike-waves or intermittent slow waves. The PPR may be restricted to posterior visual areas (i.e. local PPR…

  15. Probabilistic Gait Classification in Children with Cerebral Palsy: A Bayesian Approach

    ERIC Educational Resources Information Center

    Van Gestel, Leen; De Laet, Tinne; Di Lello, Enrico; Bruyninckx, Herman; Molenaers, Guy; Van Campenhout, Anja; Aertbelien, Erwin; Schwartz, Mike; Wambacq, Hans; De Cock, Paul; Desloovere, Kaat

    2011-01-01

    Three-dimensional gait analysis (3DGA) generates a wealth of highly variable data. Gait classifications help to reduce, simplify and interpret this vast amount of 3DGA data and thereby assist and facilitate clinical decision making in the treatment of CP. CP gait is often a mix of several clinically accepted distinct gait patterns. Therefore,…

  16. The comparison of two physiotherapeutic approaches for gait improvement in sub-acute stroke patients.

    PubMed

    Krawczyk, Maciej; Szczerbik, Ewa; Syczewska, Małgorzata

    2014-01-01

    The functional gait problems encountered by stroke patients include impaired balance, abnormal gait pattern with marked asymmetry, pathological trunk and spinal motion. Many different methods of physiotherapy are used to improve functional ability (especially gait) in stroke patients, but their efficacy and outcome are often not objectively assessed. The goal of this paper is to compare two therapeutic programs: one that is traditionally used in our rehabilitation facilities (exercises in lying position, "open chain" exercises, isolated movements of extremities with trunk stabilization) and the new one (exercises in vertical position, sitting or standing, "closed chain" exercises involving whole paretic side of the body). Fifty one stroke patients, aged 34 to 79 years, participated in the study. Patients were randomly allocated to one of the two groups. Patients underwent clinical assessment (Fugl-Meyer, Rivermead Motor Assessment, Berg Balance Scale) and instrumented gait analysis (using six-camera VICON 460 system) simultaneously three times: prior to the beginning of the rehabilitation program, after 6 weeks of the program, and after another 6 weeks of physiotherapy, at the end of rehabilitation program. Results demonstrated that both rehabilitation programs improved the gait function and clinical status in patients suffering from stroke. Despite the differences between the two programs the progress achieved by the patients in locomotor function is similar. Two equivalent physiotherapy programs could be applied during rehabilitation process depending on the patient's individual preferences and needs, as the amount of functional improvement provided by them is comparable. PMID:24708038

  17. Ankle Training With a Robotic Device Improves Hemiparetic Gait After a Stroke

    PubMed Central

    Forrester, Larry W.; Roy, Anindo; Krebs, Hermano Igo; Macko, Richard F.

    2013-01-01

    Background Task-oriented therapies such as treadmill exercise can improve gait velocity after stroke, but slow velocities and abnormal gait patterns often persist, suggesting a need for additional strategies to improve walking. Objectives To determine the effects of a 6-week visually guided, impedance controlled, ankle robotics intervention on paretic ankle motor control and gait function in chronic stroke. Methods This was a single-arm pilot study with a convenience sample of 8 stroke survivors with chronic hemiparetic gait, trained and tested in a laboratory. Subjects trained in dorsiflexion–plantarflexion by playing video games with the robot during three 1-hour training sessions weekly, totaling 560 repetitions per session. Assessments included paretic ankle ranges of motion, strength, motor control, and overground gait function. Results Improved paretic ankle motor control was seen as increased target success, along with faster and smoother movements. Walking velocity also increased significantly, whereas durations of paretic single support increased and double support decreased. Conclusions Robotic feedback training improved paretic ankle motor control with improvements in floor walking. Increased walking speeds were comparable with reports from other task-oriented, locomotor training approaches used in stroke, suggesting that a focus on ankle motor control may provide a valuable adjunct to locomotor therapies. PMID:21115945

  18. Gait analysis in forensic medicine

    NASA Astrophysics Data System (ADS)

    Larsen, Peter K.; Simonsen, Erik B.; Lynnerup, Niels

    2007-01-01

    We have combined the basic human ability to recognize other individuals with functional anatomical and biomechanical knowledge, in order to analyze the gait of perpetrators as recorded on surveillance video. The perpetrators are then compared with similar analyses of suspects. At present we give a statement to the police as to whether the perpetrator has a characteristic gait pattern compared to normal gait, and if a suspect has a comparable gait pattern. We have found agreements such as: limping, varus instability in the knee at heel strike, larger lateral flexion of the spinal column to one side than the other, inverted ankle during stance, pronounced sagittal head-movements, and marked head-shoulder posture. Based on these characteristic features, we state whether suspect and perpetrator could have the same identity but it is not possible to positively identify the perpetrator. Nevertheless, we have been involved in several cases where the court has found that this type of gait analysis, especially combined with photogrammetry, was a valuable tool. The primary requisites are surveillance cameras recording with sufficient frequency, ideally about 15 Hz, which are positioned in frontal and preferably also in profile view.

  19. Identification of abnormal motor cortex activation patterns in children with cerebral palsy by functional near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Khan, Bilal; Tian, Fenghua; Behbehani, Khosrow; Romero, Mario I.; Delgado, Mauricio R.; Clegg, Nancy J.; Smith, Linsley; Reid, Dahlia; Liu, Hanli; Alexandrakis, George

    2010-05-01

    We demonstrate the utility of functional near-infrared spectroscopy (fNIRS) as a tool for physicians to study cortical plasticity in children with cerebral palsy (CP). Motor cortex activation patterns were studied in five healthy children and five children with CP (8.4+/-2.3 years old in both groups) performing a finger-tapping protocol. Spatial (distance from center and area difference) and temporal (duration and time-to-peak) image metrics are proposed as potential biomarkers for differentiating abnormal cortical activation in children with CP from healthy pediatric controls. In addition, a similarity image-analysis concept is presented that unveils areas that have similar activation patterns as that of the maximum activation area, but are not discernible by visual inspection of standard activation images. Metrics derived from the images presenting areas of similarity are shown to be sensitive identifiers of abnormal activation patterns in children with CP. Importantly, the proposed similarity concept and related metrics may be applicable to other studies for the identification of cortical activation patterns by fNIRS.

  20. Adult-onset multiple acyl CoA dehydrogenation deficiency associated with an abnormal isoenzyme pattern of serum lactate dehydrogenase.

    PubMed

    Sugai, Fuminobu; Baba, Kousuke; Toyooka, Keiko; Liang, Wen-Chen; Nishino, Ichizo; Yamadera, Misaki; Sumi, Hisae; Fujimura, Harutoshi; Nishikawa, Yoshiro

    2012-02-01

    We report a case of a 37 year-old male with multiple acyl-CoA dehydrogenation deficiency (MADD). The patient had suffered from exercise intolerance in his hip and thigh muscles for one year. Then, restriction of carbohydrates for a diet made his symptoms rapidly deteriorate. Blood test revealed compound heterozygosity for two novel missense mutations in the electron transfer flavoprotein dehydrogenase gene (ETFDH), and an abnormal LDH isoenzyme pattern: LDH-1 (60.0%) and LDH-2 (26.0%) predominated with abnormally elevated LDH-1/LDH-2 ratio (2.3), compared with muscle-derived LDH-5 (4.0%). Oral riboflavin treatment significantly improved his exercise intolerance and the LDH profile: LDH-1 (34.4%), LDH-2 (34.9%), LDH-5 (6.9%) and LDH-1/LDH-2 ratio (1.0). The abnormal LDH isoenzyme pattern may be one feature of adult-onset MADD selectively affecting type I muscle fibers with relatively high LDH-1 content. PMID:21907580

  1. Effects of ankle foot orthosis in stiff knee gait in adults with hemiplegia.

    PubMed

    Gatti, Marcelo Andrés; Freixes, Orestes; Fernández, Sergio Anibal; Rivas, Maria Elisa; Crespo, Marcos; Waldman, Silvina V; Olmos, Lisandro Emilio

    2012-10-11

    Stroke survivors present a less efficient gait compared to healthy subjects due to abnormal knee flexion during the swing phase of gait, associated with spasticity of the rectus femoris muscle and overactivity of the ankle plantarflexors. It is relevant to understand the effect of the ankle foot orthosis (AFO) on gait in individuals with plantarflexor spasticity. The aim of this study was to compare the knee kinematics with an AFO/footwear combination and barefoot in post-stroke subjects with plantarflexor spasticity. Ten subjects with chronic hemiplegia were measured. Two kinematic variables were assessed during the swing phase of the paretic limb: knee flexion angle at toeoff and peak knee flexion angle. We also analyzed gait speed and step length of the non-paretic limb. All variables were obtained with and without the orthosis. Kinematic data were acquired using a motion capture system (ELITE). Subjects wearing an AFO showed significant improvements in gait speed (0.62 m/s (0.08 SD) vs. 0.47 m/s (0.13 SD) (p=0.007)), step length of the non-paretic limb (42 cm (5.9 SD) vs. 33.5 cm (6.6 SD) (p=0.005)) and peak knee flexion angle during the swing phase: 30.7° (14.1° SD) vs. 26.3° (11.7° SD) p=0.005. No significant differences were obtained in the knee flexion angle at toeoff between no AFO and AFO conditions. We described benefits with AFO/footwear use in the kinematics of the knee, the step length of the non-paretic limb, and the gait velocity in hemiplegic subjects after mild to moderate stroke. We conclude that the use of an AFO can improve the gait pattern and increase velocity in these subjects.

  2. How crouch gait can dynamically induce stiff-knee gait.

    PubMed

    van der Krogt, Marjolein M; Bregman, Daan J J; Wisse, Martijn; Doorenbosch, Caroline A M; Harlaar, Jaap; Collins, Steven H

    2010-04-01

    Children with cerebral palsy frequently experience foot dragging and tripping during walking due to a lack of adequate knee flexion in swing (stiff-knee gait). Stiff-knee gait is often accompanied by an overly flexed knee during stance (crouch gait). Studies on stiff-knee gait have mostly focused on excessive knee muscle activity during (pre)swing, but the passive dynamics of the limbs may also have an important effect. To examine the effects of a crouched posture on swing knee flexion, we developed a forward-dynamic model of human walking with a passive swing knee, capable of stable cyclic walking for a range of stance knee crouch angles. As crouch angle during stance was increased, the knee naturally flexed much less during swing, resulting in a 'stiff-knee' gait pattern and reduced foot clearance. Reduced swing knee flexion was primarily due to altered gravitational moments around the joints during initial swing. We also considered the effects of increased push-off strength and swing hip flexion torque, which both increased swing knee flexion, but the effect of crouch angle was dominant. These findings demonstrate that decreased knee flexion during swing can occur purely as the dynamical result of crouch, rather than from altered muscle function or pathoneurological control alone.

  3. A real-time auditory feedback system for retraining gait.

    PubMed

    Maulucci, Ruth A; Eckhouse, Richard H

    2011-01-01

    Stroke is the third leading cause of death in the United States and the principal cause of major long-term disability, incurring substantial distress as well as medical cost. Abnormal and inefficient gait patterns are widespread in survivors of stroke, yet gait is a major determinant of independent living. It is not surprising, therefore, that improvement of walking function is the most commonly stated priority of the survivors. Although many such individuals achieve the goal of walking, the caliber of their walking performance often limits endurance and quality of life. The ultimate goal of the research presented here is to use real-time auditory feedback to retrain gait in patients with chronic stroke. The strategy is to convert the motion of the foot into an auditory signal, and then use this auditory signal as feedback to inform the subject of the existence as well as the magnitude of error during walking. The initial stage of the project is described in this paper. The design and implementation of the new feedback method for lower limb training is explained. The question of whether the patient is physically capable of handling such training is explored. PMID:22255509

  4. Identification of Abnormal System Noise Temperature Patterns in Deep Space Network Antennas Using Neural Network Trained Fuzzy Logic

    NASA Technical Reports Server (NTRS)

    Lu, Thomas; Pham, Timothy; Liao, Jason

    2011-01-01

    This paper presents the development of a fuzzy logic function trained by an artificial neural network to classify the system noise temperature (SNT) of antennas in the NASA Deep Space Network (DSN). The SNT data were classified into normal, marginal, and abnormal classes. The irregular SNT pattern was further correlated with link margin and weather data. A reasonably good correlation is detected among high SNT, low link margin and the effect of bad weather; however we also saw some unexpected non-correlations which merit further study in the future.

  5. Patterns of Gray Matter Abnormalities in Schizophrenia Based on an International Mega-analysis.

    PubMed

    Gupta, Cota Navin; Calhoun, Vince D; Rachakonda, Srinivas; Chen, Jiayu; Patel, Veena; Liu, Jingyu; Segall, Judith; Franke, Barbara; Zwiers, Marcel P; Arias-Vasquez, Alejandro; Buitelaar, Jan; Fisher, Simon E; Fernandez, Guillen; van Erp, Theo G M; Potkin, Steven; Ford, Judith; Mathalon, Daniel; McEwen, Sarah; Lee, Hyo Jong; Mueller, Bryon A; Greve, Douglas N; Andreassen, Ole; Agartz, Ingrid; Gollub, Randy L; Sponheim, Scott R; Ehrlich, Stefan; Wang, Lei; Pearlson, Godfrey; Glahn, David C; Sprooten, Emma; Mayer, Andrew R; Stephen, Julia; Jung, Rex E; Canive, Jose; Bustillo, Juan; Turner, Jessica A

    2015-09-01

    Analyses of gray matter concentration (GMC) deficits in patients with schizophrenia (Sz) have identified robust changes throughout the cortex. We assessed the relationships between diagnosis, overall symptom severity, and patterns of gray matter in the largest aggregated structural imaging dataset to date. We performed both source-based morphometry (SBM) and voxel-based morphometry (VBM) analyses on GMC images from 784 Sz and 936 controls (Ct) across 23 scanning sites in Europe and the United States. After correcting for age, gender, site, and diagnosis by site interactions, SBM analyses showed 9 patterns of diagnostic differences. They comprised separate cortical, subcortical, and cerebellar regions. Seven patterns showed greater GMC in Ct than Sz, while 2 (brainstem and cerebellum) showed greater GMC for Sz. The greatest GMC deficit was in a single pattern comprising regions in the superior temporal gyrus, inferior frontal gyrus, and medial frontal cortex, which replicated over analyses of data subsets. VBM analyses identified overall cortical GMC loss and one small cluster of increased GMC in Sz, which overlapped with the SBM brainstem component. We found no significant association between the component loadings and symptom severity in either analysis. This mega-analysis confirms that the commonly found GMC loss in Sz in the anterior temporal lobe, insula, and medial frontal lobe form a single, consistent spatial pattern even in such a diverse dataset. The separation of GMC loss into robust, repeatable spatial patterns across multiple datasets paves the way for the application of these methods to identify subtle genetic and clinical cohort effects.

  6. Characteristics of the electromyographic patterns of lower limb muscles during gait in patients with Parkinson's disease when OFF and ON L-Dopa treatment.

    PubMed

    Cioni, M; Richards, C L; Malouin, F; Bedard, P J; Lemieux, R

    1997-08-01

    The purpose of this study was to compare the electromyographic (EMG) behavior of the triceps surae (TS), tibialis anterior (TA), quadriceps and hamstring muscles of the lower limbs during self-initiated free gait in a group of patients (n = 15) with Parkinson's disease (PD), when OFF and ON L-Dopa, with that of normal controls. When OFF L-Dopa, we observed qualitative disturbances in muscle activation patterns, such as an absence or extreme reduction in TA activations in early stance or during the early and late swing phases. Other disturbances included flatter profiles of the TS activation burst at push off, and temporal alterations that included prolonged activation of the proximal muscles during the stance phase. Statistical analysis showed that the TA was the most affected muscle in most of the patients particularly during the activation burst in late swing (p < .0004). After medication (ON L-Dopa), the amplitude and timing of distal muscle activations became more similar to normal values, with the increase in EMG amplitude being dramatic in some patients. In the proximal muscles, the effects on EMG amplitude were less marked and prolonged activation often persisted even after the administration of L-Dopa.

  7. Hardware Development and Locomotion Control Strategy for an Over-Ground Gait Trainer: NaTUre-Gaits

    PubMed Central

    Low, Kin Huat; Qu, Xingda; Lim, Hup Boon; Hoon, Kay Hiang

    2014-01-01

    Therapist-assisted body weight supported (TABWS) gait rehabilitation was introduced two decades ago. The benefit of TABWS in functional recovery of walking in spinal cord injury and stroke patients has been demonstrated and reported. However, shortage of therapists, labor-intensiveness, and short duration of training are some limitations of this approach. To overcome these deficiencies, robotic-assisted gait rehabilitation systems have been suggested. These systems have gained attentions from researchers and clinical practitioner in recent years. To achieve the same objective, an over-ground gait rehabilitation system, NaTUre-gaits, was developed at the Nanyang Technological University. The design was based on a clinical approach to provide four main features, which are pelvic motion, body weight support, over-ground walking experience, and lower limb assistance. These features can be achieved by three main modules of NaTUre-gaits: 1) pelvic assistance mechanism, mobile platform, and robotic orthosis. Predefined gait patterns are required for a robotic assisted system to follow. In this paper, the gait pattern planning for NaTUre-gaits was accomplished by an individual-specific gait pattern prediction model. The model generates gait patterns that resemble natural gait patterns of the targeted subjects. The features of NaTUre-gaits have been demonstrated by walking trials with several subjects. The trials have been evaluated by therapists and doctors. The results show that 10-m walking trial with a reduction in manpower. The task-specific repetitive training approach and natural walking gait patterns were also successfully achieved. PMID:27170876

  8. Patterns of Gray Matter Abnormalities in Schizophrenia Based on an International Mega-analysis

    PubMed Central

    Gupta, Cota Navin; Calhoun, Vince D.; Rachakonda, Srinivas; Chen, Jiayu; Patel, Veena; Liu, Jingyu; Segall, Judith; Franke, Barbara; Zwiers, Marcel P.; Arias-Vasquez, Alejandro; Buitelaar, Jan; Fisher, Simon E.; Fernandez, Guillen; van Erp, Theo G. M.; Potkin, Steven; Ford, Judith; Mathalon, Daniel; McEwen, Sarah; Lee, Hyo Jong; Mueller, Bryon A.; Greve, Douglas N.; Andreassen, Ole; Agartz, Ingrid; Gollub, Randy L.; Sponheim, Scott R.; Ehrlich, Stefan; Wang, Lei; Pearlson, Godfrey; Glahn, David C.; Sprooten, Emma; Mayer, Andrew R.; Stephen, Julia; Jung, Rex E.; Canive, Jose; Bustillo, Juan; Turner, Jessica A.

    2015-01-01

    Analyses of gray matter concentration (GMC) deficits in patients with schizophrenia (Sz) have identified robust changes throughout the cortex. We assessed the relationships between diagnosis, overall symptom severity, and patterns of gray matter in the largest aggregated structural imaging dataset to date. We performed both source-based morphometry (SBM) and voxel-based morphometry (VBM) analyses on GMC images from 784 Sz and 936 controls (Ct) across 23 scanning sites in Europe and the United States. After correcting for age, gender, site, and diagnosis by site interactions, SBM analyses showed 9 patterns of diagnostic differences. They comprised separate cortical, subcortical, and cerebellar regions. Seven patterns showed greater GMC in Ct than Sz, while 2 (brainstem and cerebellum) showed greater GMC for Sz. The greatest GMC deficit was in a single pattern comprising regions in the superior temporal gyrus, inferior frontal gyrus, and medial frontal cortex, which replicated over analyses of data subsets. VBM analyses identified overall cortical GMC loss and one small cluster of increased GMC in Sz, which overlapped with the SBM brainstem component. We found no significant association between the component loadings and symptom severity in either analysis. This mega-analysis confirms that the commonly found GMC loss in Sz in the anterior temporal lobe, insula, and medial frontal lobe form a single, consistent spatial pattern even in such a diverse dataset. The separation of GMC loss into robust, repeatable spatial patterns across multiple datasets paves the way for the application of these methods to identify subtle genetic and clinical cohort effects. PMID:25548384

  9. Patterns of Gray Matter Abnormalities in Schizophrenia Based on an International Mega-analysis.

    PubMed

    Gupta, Cota Navin; Calhoun, Vince D; Rachakonda, Srinivas; Chen, Jiayu; Patel, Veena; Liu, Jingyu; Segall, Judith; Franke, Barbara; Zwiers, Marcel P; Arias-Vasquez, Alejandro; Buitelaar, Jan; Fisher, Simon E; Fernandez, Guillen; van Erp, Theo G M; Potkin, Steven; Ford, Judith; Mathalon, Daniel; McEwen, Sarah; Lee, Hyo Jong; Mueller, Bryon A; Greve, Douglas N; Andreassen, Ole; Agartz, Ingrid; Gollub, Randy L; Sponheim, Scott R; Ehrlich, Stefan; Wang, Lei; Pearlson, Godfrey; Glahn, David C; Sprooten, Emma; Mayer, Andrew R; Stephen, Julia; Jung, Rex E; Canive, Jose; Bustillo, Juan; Turner, Jessica A

    2015-09-01

    Analyses of gray matter concentration (GMC) deficits in patients with schizophrenia (Sz) have identified robust changes throughout the cortex. We assessed the relationships between diagnosis, overall symptom severity, and patterns of gray matter in the largest aggregated structural imaging dataset to date. We performed both source-based morphometry (SBM) and voxel-based morphometry (VBM) analyses on GMC images from 784 Sz and 936 controls (Ct) across 23 scanning sites in Europe and the United States. After correcting for age, gender, site, and diagnosis by site interactions, SBM analyses showed 9 patterns of diagnostic differences. They comprised separate cortical, subcortical, and cerebellar regions. Seven patterns showed greater GMC in Ct than Sz, while 2 (brainstem and cerebellum) showed greater GMC for Sz. The greatest GMC deficit was in a single pattern comprising regions in the superior temporal gyrus, inferior frontal gyrus, and medial frontal cortex, which replicated over analyses of data subsets. VBM analyses identified overall cortical GMC loss and one small cluster of increased GMC in Sz, which overlapped with the SBM brainstem component. We found no significant association between the component loadings and symptom severity in either analysis. This mega-analysis confirms that the commonly found GMC loss in Sz in the anterior temporal lobe, insula, and medial frontal lobe form a single, consistent spatial pattern even in such a diverse dataset. The separation of GMC loss into robust, repeatable spatial patterns across multiple datasets paves the way for the application of these methods to identify subtle genetic and clinical cohort effects. PMID:25548384

  10. Abnormal fMRI Activation Pattern during Story Listening in Individuals with Down Syndrome

    ERIC Educational Resources Information Center

    Reynolds Losin, Elizabeth A.; Rivera, Susan M.; O'Hare, Elizabeth D.; Sowell, Elizabeth R.; Pinter, Joseph D.

    2009-01-01

    Down syndrome is characterized by disproportionately severe impairments of speech and language, yet little is known about the neural underpinnings of these deficits. We compared fMRI activation patterns during passive story listening in 9 young adults with Down syndrome and 9 approximately age-matched, typically developing controls. The typically…

  11. Teachers' Knowledge of Normal and Abnormal Elimination Patterns in Elementary School Children

    ERIC Educational Resources Information Center

    Boyt, Margaret A.

    2005-01-01

    Dysfunctional elimination may be learned, to some degree. Because children spend nearly half of their waking hours at school, there is the potential for school to have a significant impact on their elimination patterns. Surveys were mailed to 1,000 randomly selected Iowa public elementary school teachers; 467 of the surveys were returned. Findings…

  12. Abnormal metabolic pattern associated with cognitive impairment in Parkinson's disease: a validation study.

    PubMed

    Meles, Sanne K; Tang, Chris C; Teune, Laura K; Dierckx, Rudi A; Dhawan, Vijay; Mattis, Paul J; Leenders, Klaus L; Eidelberg, David

    2015-09-01

    Cognitive deficits in Parkinson's disease (PD) have been associated with a specific metabolic covariance pattern. Although the expression of this PD cognition-related pattern (PDCP) correlates with neuropsychological performance, it is not known whether the PDCP topography is reproducible across PD populations. We therefore sought to identify a PDCP topography in a new sample comprised of 19 Dutch PD subjects. Network analysis of metabolic scans from these individuals revealed a significant PDCP that resembled the original network topography. Expression values for the new PDCP correlated (P=0.001) with executive dysfunction on the Frontal Assessment Battery (FAB). Subject scores for the new PDCP correlated (P<0.001) with corresponding values for the original pattern, which also correlated (P<0.005) with FAB scores in this patient group. For further validation, subject scores for the new PDCP were computed in an independent group of 86 American PD patients. In this cohort, subject scores for the new and original PDCP topographies were closely correlated (P<0.001); significant correlations between pattern expression and cognitive performance (P<0.05) were observed for both PDCP topographies. These findings suggest that the PDCP is a replicable imaging marker of PD cognitive dysfunction. PMID:26058693

  13. Motion cue analysis for parkinsonian gait recognition.

    PubMed

    Khan, Taha; Westin, Jerker; Dougherty, Mark

    2013-01-01

    This paper presents a computer-vision based marker-free method for gait-impairment detection in Patients with Parkinson's disease (PWP). The system is based upon the idea that a normal human body attains equilibrium during the gait by aligning the body posture with Axis-of-Gravity (AOG) using feet as the base of support. In contrast, PWP appear to be falling forward as they are less-able to align their body with AOG due to rigid muscular tone. A normal gait exhibits periodic stride-cycles with stride-angle around 45o between the legs, whereas PWP walk with shortened stride-angle with high variability between the stride-cycles. In order to analyze Parkinsonian-gait (PG), subjects were videotaped with several gait-cycles. The subject's body was segmented using a color-segmentation method to form a silhouette. The silhouette was skeletonized for motion cues extraction. The motion cues analyzed were stride-cycles (based on the cyclic leg motion of skeleton) and posture lean (based on the angle between leaned torso of skeleton and AOG). Cosine similarity between an imaginary perfect gait pattern and the subject gait patterns produced 100% recognition rate of PG for 4 normal-controls and 3 PWP. Results suggested that the method is a promising tool to be used for PG assessment in home-environment. PMID:23407764

  14. Abnormal luteinizing hormone response patterns to synthetic gonadotrophin releasing hormone in patients with polycystic ovarian syndrome.

    PubMed

    Katz, M; Carr, P J

    1976-08-01

    Basal gonadotrophin and sex steroid levels and responses to an intravenous injection of 100 mug gonadotrophin releasing hormone (Gn-RH) have been studied in 15 patients with polycystic ovaries. Mean basal LH concentration was raised and an excessive, exaggerated and prolonged response was observed after Gn-RH treatment, but patients could further be subdivided into two functional groups on the basis of their basal LH values and LH response patterns. Evidence was also produced which suggested a breakdown in the negative feedback mechanism in these patients.

  15. Mice with Dab1 or Vldlr insufficiency exhibit abnormal neonatal vocalization patterns

    PubMed Central

    Fraley, E. R.; Burkett, Z. D.; Day, N. F.; Schwartz, B. A.; Phelps, P. E.; White, S. A.

    2016-01-01

    Genetic and epigenetic changes in components of the Reelin-signaling pathway (RELN, DAB1) are associated with autism spectrum disorder (ASD) risk. Social communication deficits are a key component of the ASD diagnostic criteria, but the underlying neurogenetic mechanisms remain unknown. Reln insufficient mice exhibit ASD-like behavioral phenotypes including altered neonatal vocalization patterns. Reelin affects multiple pathways including through the receptors, Very low-density lipoprotein receptor (Vldlr), Apolipoprotein receptor 2 (Apoer2), and intracellular signaling molecule Disabled-1 (Dab1). As Vldlr was previously implicated in avian vocalization, here we investigate vocalizations of neonatal mice with a reduction or absence of these components of the Reelin-signaling pathway. Mice with low or no Dab1 expression exhibited reduced calling rates, altered call-type usage, and differential vocal development trajectories. Mice lacking Vldlr expression also had altered call repertoires, and this effect was exacerbated by deficiency in Apoer2. Together with previous findings, these observations 1) solidify a role for Reelin in vocal communication of multiple species, 2) point to the canonical Reelin-signaling pathway as critical for development of normal neonatal calling patterns in mice, and 3) suggest that mutants in this pathway could be used as murine models for Reelin-associated vocal deficits in humans. PMID:27184477

  16. System of reporting and comparing influence of ambulatory aids on gait.

    PubMed

    Smidt, G L; Mommens, M A

    1980-05-01

    The purposes of this study were to 1) present a standardized approach for describing gait when assistive devices are used, 2) report reference data for unassisted and assisted gait patterns for normal adults, and 3) discuss clinical implications for selected variables of gait. Using an automated gait system, measurements for temporal and distance factors and accelerometry were obtained for 25 normal young adults. In addition to the formulation of a new system for describing gait patterns when assistive devices are used, the results of the study were that 1) subjects walked slower with ambulatory aids than without them, 2) assisted gaits with the same number of counts per cycle tended to have similar measurements, 3) reciprocal swing times and stance times were symmetrical for all types of gait studied, 4) double stance times and step times were asymmetrical for three types of assisted gait, and 5) vertical accelerations were disproportionately elevated for most assisted gaits.

  17. Spreading photoparoxysmal EEG response is associated with an abnormal cortical excitability pattern.

    PubMed

    Siniatchkin, Michael; Groppa, Sergey; Jerosch, Bettina; Muhle, Hiltrud; Kurth, Christoph; Shepherd, Alex J; Siebner, Hartwig; Stephani, Ulrich

    2007-01-01

    Photosensitivity or photoparoxysmal response (PPR) is a highly heritable electroencephalographic trait characterized by an abnormal cortical response to intermittent photic stimulation (IPS). In PPR-positive individuals, IPS induces spikes, spike-waves or intermittent slow waves. The PPR may be restricted to posterior visual areas (i.e. local PPR with occipital spikes only) or spread to anterior non-visual cortical regions (i.e. PPR with propagation). The mechanisms underlying the PPR and causing its spread remain to be clarified. In unmedicated PPR-positive individuals and PPR-negative control participants without any history of previous seizures, we used focal transcranial magnetic stimulation (TMS) to investigate the excitability of the visual or primary motor cortex (M1). In the first experiment [18 healthy control subjects (i.e. without PPR in electroencephalography: 6 females, mean age 26.5 +/- 7.34 years) and 17 healthy participants with PPR (7 females, mean age 25.18 +/- 12.2 years) were studied], occipital TMS was used to elicit phosphenes or to suppress the visual perception of letter trigrams. PPR-positive individuals with propagation had lower phosphene thresholds and steeper stimulus-response curves than individuals without PPR or with occipital spikes only. Occipital TMS also induced a stronger suppression of visual perception in PPR-positive subjects with propagation relative to subjects without PPR or with occipital spikes. In the second experiment, we applied TMS over the right M1 without concurrent IPS and measured the motor threshold, the stimulus response curve, and the duration of the cortical silent period (CSP) in PPR positive individuals with propagation and in PPR-negative control participants [15 right-handed healthy subjects without PPR (3 males, mean age 17.7 +/- 3.6 years) and 14 right-handed healthy individuals showing a PPR with propagation (3 males, mean age 17.4 +/- 3.9 years)]. PPR-positive individuals showed no changes in these

  18. Sporadic hyperekplexia presenting with an ataxic gait.

    PubMed

    Rouco, Idoia; Bilbao, Iker; Losada, Jose; Maestro, Iratxe; Zarranz, Juan Jose

    2014-02-01

    We describe a 62-year-old man with a sporadic form of hyperekplexia who presented with an unsteady gait, present since the age of 47. His clinical examination revealed an insecure broad-based gait and difficulty with tandem walking but no other abnormalities. For nearly a decade the patient was misdiagnosed with an idiopathic ataxia. A video electroencephalogram combined with an electromyogram during sudden auditory stimulus demonstrated an excessive startle response. An extensive work-up ruled out all the known causes of symptomatic hyperekplexia including anti-glycine receptor antibodies. Treatment with clonazepam markedly reduced the threshold and intensity of the startle response, enabling him to recover independence. Hyperekplexia is frequently associated with an awkward and hesitating gait, but these gait abnormalities might be confused with other causes of gait disorders if one is not aware of this disease. We report this patient to highlight that a correct diagnosis of hyperekplexia is crucial, because its treatment may change quality of life. PMID:24054400

  19. Effect of the Modulation of Optic Flow Speed on Gait Parameters in Children with Hemiplegic Cerebral Palsy

    PubMed Central

    Lim, Hyungwon

    2014-01-01

    [Purpose] We investigated the effects of modulation of the optic flow speed on gait parameters in children with hemiplegic cerebral palsy. [Methods] We examined 10 children with hemiplegic cerebral palsy. The children underwent gait analysis under 3 different conditions of optic flow speed: slow, normal, and fast optic flow speed. The children walked across the walkway of a GAITRite system, while watching a virtual reality screen, and walking velocity, cadence, stride length, step length, single support time, and double support time were recorded. [Results] Compared with the other applied flow speed conditions, the fast optic flow speed (2 times the normal speed) significantly increased walking velocity, cadence, normalized step length, base of support, and single support cycle of both the paretic and non-paretic lower limbs. Moreover, compared with the other applied flow speed conditions, the slow optic flow speed (0.25 times the normal speed) yielded a significantly decreased walking velocity, cadence, normalized step length, base of support, and single support cycle for both the paretic and non-paretic lower limbs. [Conclusion] The gait parameters of children with hemiplegic cerebral palsy are altered by modulation of the optic flow speed. Thus, we believe that gait training involving modulation of the optic flow speed is feasible and suitable for resolving abnormal gait patterns in children with hemiplegic cerebral palsy. PMID:24567695

  20. Gait quality assessment using self-organising artificial neural networks.

    PubMed

    Barton, Gabor; Lisboa, Paulo; Lees, Adrian; Attfield, Steve

    2007-03-01

    In this study, the challenge to maximise the potential of gait analysis by employing advanced methods was addressed by using self-organising neural networks to quantify the deviation of patients' gait from normal. Data including three-dimensional joint angles, moments and powers of the two lower limbs and the pelvis were used to train Kohonen artificial neural networks to learn an abstract definition of normal gait. Subsequently, data from patients with gait problems were presented to the network which quantified the quality of gait in the form of a single curve by calculating the quantisation error during the gait cycle. A sensitivity analysis involving the manipulation of gait variables' weighting was able to highlight specific causes of the deviation including the anatomical location and the timing of wrong gait patterns. Use of the quantisation error can be regarded as an extension of previously described gait indices because it measures the goodness of gait and additionally provides information related to the causes underlying gait deviations.

  1. Gait transitions in simulated reduced gravity.

    PubMed

    Ivanenko, Yuri P; Labini, Francesca Sylos; Cappellini, Germana; Macellari, Velio; McIntyre, Joseph; Lacquaniti, Francesco

    2011-03-01

    Gravity has a strong effect on gait and the speed of gait transitions. A gait has been defined as a pattern of locomotion that changes discontinuously at the transition to another gait. On Earth, during gradual speed changes, humans exhibit a sudden discontinuous switch from walking to running at a specific speed. To study the effects of altered gravity on both the stance and swing legs, we developed a novel unloading exoskeleton that allows a person to step in simulated reduced gravity by tilting the body relative to the vertical. Using different simulation techniques, we confirmed that at lower gravity levels the transition speed is slower (in accordance with the previously reported Froude number ∼0.5). Surprisingly, however, we found that at lower levels of simulated gravity the transition between walking and running was generally gradual, without any noticeable abrupt change in gait parameters. This was associated with a significant prolongation of the swing phase, whose duration became virtually equal to that of stance in the vicinity of the walk-run transition speed, and with a gradual shift from inverted-pendulum gait (walking) to bouncing gait (running).

  2. Patients with type II diabetes mellitus display reduced toe-obstacle clearance with altered gait patterns during obstacle-crossing.

    PubMed

    Liu, Ming-Wei; Hsu, Wei-Chun; Lu, Tung-Wu; Chen, Hao-Ling; Liu, Hwa-Chang

    2010-01-01

    Patients with type II diabetes mellitus (DM) have been reported to be at high risk of falls that may be further increased by the effects of challenging activities such as obstacle-crossing. The purpose of this study was to compare the end-point trajectory and joint kinematic and kinetic patterns of the lower extremities between healthy subjects and individuals with DM during obstacle-crossing with the leading limb. Fourteen patients with type II DM, with no to minimal peripheral neuropathy (PN), and 14 healthy controls walked and crossed obstacles of three different heights (10%, 20% and 30% of leg length) while kinematic and kinetic data were measured using a motion analysis system and two forceplates. Compared to normal, the DM group had similar walking speeds and horizontal footobstacle distances but significantly reduced leading toe-obstacle clearances, suggesting an increased risk of tripping over the obstacle. When the swing toe was above the obstacle, the DM group showed greater pelvic anterior tilt, stance ankle dorsiflexion, and smaller swing hip abduction, with reduced hip abductor moments but greater knee flexor and ankle plantarflexor and adductor moments. It is suggested that patients with type II DM, with no or minimal PN, should also be targeted for prevention of falls. Possible therapeutic interventions to decrease falls for those with DM may include strengthening of the knee flexors and ankle plantarflexor muscles, together with proprioception and balance training. PMID:19875290

  3. Interocular suppression patterns in binocularly abnormal observers using luminance- and contrast-modulated noise stimuli.

    PubMed

    Chima, Akash S; Formankiewicz, Monika A; Waugh, Sarah J

    2016-08-01

    In binocular viewing, images presented to the amblyopic eye are suppressed in the cortex to prevent confusion or diplopia. The present study measures depth and extent of interocular suppression across the central circular 24° visual field in observers with strabismus and microstrabismus. Visual stimuli were concentric rings of alternating polarity, each divided into sectors. Rings were defined by luminance (L), luminance-modulated noise (LM), or contrast-modulated noise (CM). They were viewed binocularly except for the tested ring, which was viewed dichoptically, so that the modulation of one sector presented to the weaker or amblyopic eye was adjusted to perceptually match the surrounding ring presented to the preferred eye. A two alternative forced-choice paradigm combined with a staircase procedure allowed for measurement of the point of subjective equality, or perceptual match. Depth of suppression was calculated as the difference between physical modulations presented to the two eyes at this point. Strabismic participants showed suppression deeper centrally than peripherally, and in one hemifield of the visual field more than the other. Suppression was deeper for L than LM, and CM than LM stimuli. Microstrabismic suppression was weaker than that of strabismics, central for L and LM stimuli, with suppression of CM stimuli being broader, deeper and more in one hemifield. Suppression depth was positively correlated with interocular visual acuity difference and stereoacuity reduction. Clinically, LM stimuli could be used for assessment of deeper amblyopes to assess suppression patterns, while more sensitive detection of mild suppression would be possible using CM stimuli.

  4. The Effect of Body Weight Support Treadmill Training on Gait Recovery, Proximal Lower Limb Motor Pattern, and Balance in Patients with Subacute Stroke

    PubMed Central

    Mao, Yu-Rong; Lo, Wai Leung; Lin, Qiang; Li, Le; Xiao, Xiang; Raghavan, Preeti; Huang, Dong-Feng

    2015-01-01

    Objective. Gait performance is an indicator of mobility impairment after stroke. This study evaluated changes in balance, lower extremity motor function, and spatiotemporal gait parameters after receiving body weight supported treadmill training (BWSTT) and conventional overground walking training (CT) in patients with subacute stroke using 3D motion analysis. Setting. Inpatient department of rehabilitation medicine at a university-affiliated hospital. Participants. 24 subjects with unilateral hemiplegia in the subacute stage were randomized to the BWSTT (n = 12) and CT (n = 12) groups. Parameters were compared between the two groups. Data from twelve age matched healthy subjects were recorded as reference. Interventions. Patients received gait training with BWSTT or CT for an average of 30 minutes/day, 5 days/week, for 3 weeks. Main Outcome Measures. Balance was measured by the Brunel balance assessment. Lower extremity motor function was evaluated by the Fugl-Meyer assessment scale. Kinematic data were collected and analyzed using a gait capture system before and after the interventions. Results. Both groups improved on balance and lower extremity motor function measures (P < 0.05), with no significant difference between the two groups after intervention. However, kinematic data were significantly improved (P < 0.05) after BWSTT but not after CT. Maximum hip extension and flexion angles were significantly improved (P < 0.05) for the BWSTT group during the stance and swing phases compared to baseline. Conclusion. In subacute patients with stroke, BWSTT can lead to improved gait quality when compared with conventional gait training. Both methods can improve balance and motor function. PMID:26649295

  5. Interocular suppression patterns in binocularly abnormal observers using luminance- and contrast-modulated noise stimuli.

    PubMed

    Chima, Akash S; Formankiewicz, Monika A; Waugh, Sarah J

    2016-08-01

    In binocular viewing, images presented to the amblyopic eye are suppressed in the cortex to prevent confusion or diplopia. The present study measures depth and extent of interocular suppression across the central circular 24° visual field in observers with strabismus and microstrabismus. Visual stimuli were concentric rings of alternating polarity, each divided into sectors. Rings were defined by luminance (L), luminance-modulated noise (LM), or contrast-modulated noise (CM). They were viewed binocularly except for the tested ring, which was viewed dichoptically, so that the modulation of one sector presented to the weaker or amblyopic eye was adjusted to perceptually match the surrounding ring presented to the preferred eye. A two alternative forced-choice paradigm combined with a staircase procedure allowed for measurement of the point of subjective equality, or perceptual match. Depth of suppression was calculated as the difference between physical modulations presented to the two eyes at this point. Strabismic participants showed suppression deeper centrally than peripherally, and in one hemifield of the visual field more than the other. Suppression was deeper for L than LM, and CM than LM stimuli. Microstrabismic suppression was weaker than that of strabismics, central for L and LM stimuli, with suppression of CM stimuli being broader, deeper and more in one hemifield. Suppression depth was positively correlated with interocular visual acuity difference and stereoacuity reduction. Clinically, LM stimuli could be used for assessment of deeper amblyopes to assess suppression patterns, while more sensitive detection of mild suppression would be possible using CM stimuli. PMID:27580040

  6. Visualisation of gait data with Kohonen self-organising neural maps.

    PubMed

    Barton, Gabor; Lees, Adrian; Lisboa, Paulo; Attfield, Steve

    2006-08-01

    Self-organising artificial neural networks were used to reduce the complexity of joint kinematic and kinetic data, which form part of a typical instrumented gait assessment. Three-dimensional joint angles, moments and powers during the gait cycle were projected from the multi-dimensional data space onto a topological neural map, which thereby identified gait stem-patterns. Patients were positioned on the map in relation to each other and this enabled them to be compared from their gait patterns. The visualisation of large amounts of complex data in a two-dimensional map labelled with gait patterns is a step towards more objective analysis protocols which may enhance decision making.

  7. Dynamic Principles of Gait and Their Clinical Implications

    PubMed Central

    Donelan, J. Maxwell

    2010-01-01

    A healthy gait pattern depends on an array of biomechanical features, orchestrated by the central nervous system for economy and stability. Injuries and other pathologies can alter these features and result in substantial gait deficits, often with detrimental consequences for energy expenditure and balance. An understanding of the role of biomechanics in the generation of healthy gait, therefore, can provide insight into these deficits. This article examines the basic principles of gait from the standpoint of dynamic walking, an approach that combines an inverted pendulum model of the stance leg with a pendulum model of the swing leg and its impact with the ground. The heel-strike at the end of each step has dynamic effects that can contribute to a periodic gait and its passive stability. Biomechanics, therefore, can account for much of the gait pattern, with additional motor inputs that are important for improving economy and stability. The dynamic walking approach can predict the consequences of disruptions to normal biomechanics, and the associated observations can help explain some aspects of impaired gait. This article reviews the basic principles of dynamic walking and the associated experimental evidence for healthy gait and then considers how the principles may be applied to clinical gait pathologies. PMID:20023002

  8. Primary and secondary gait deviations of stroke survivors and their association with gait performance

    PubMed Central

    Kim, Hyung-Sik; Chung, Soon-Cheol; Choi, Mi-Hyun; Gim, Seon-Young; Kim, Woo-Ram; Tack, Gye-Rae; Lim, Dae-Woon; Chun, Sung-Kuk; Kim, Jin-Wook; Mun, Kyung-Ryoul

    2016-01-01

    [Purpose] Stroke survivors exhibit abnormal pelvic motion and significantly deteriorated gait performance. Although the gait of stroke survivors has been evaluated at the primary level pertaining to ankle, knee, and hip motions, secondary deviations involving the pelvic motions are strongly related to the primary level. Therefore, the aim of this study was to identify the kinematic differences of the primary and secondary joints and to identify mechanism differences that alter the gait performance of stroke survivors. [Subjects and Methods] Five healthy subjects and five stroke survivors were recruited. All the subjects were instructed to walk at a self-selected speed. The joint kinematics and gait parameters were calculated. [Results] For the stroke survivors, the range of motion of the primary-joint motions were significantly reduced, and the secondary-joint motions were significantly increased. Additionally, for the healthy subjects, the primary joint kinematics were the main factors ensuring gait performance, whereas for the stoke survivors, the secondary-joint motions were the main factors. [Conclusion] The results indicate that while increasing the range of motion of primary-joint movements is the main target to achieve, there is a strong need to constrain and support pelvic motions in order to improve the outcome of gait rehabilitation. PMID:27799710

  9. [Application and evaluation of the VICON system in gait analysis].

    PubMed

    Lin, J H; Chou, Y L; Ju, M S; Sung, Y T

    1990-01-01

    By employing the VICON system, segment angular displacement, velocity and acceleration of the lower limbs were achieved from an Above-Knee (A/K) Amputee using a constant friction prosthesis during the swing phase of the gait cycle. By applying computer for data analysis and inputing anthropometric data of the (A/K) Amputee, kinematic trajectory and a stick diagram of lower limbs were obtained. The data were then compared with those obtained from normal subjects. The results showed that the VICON system can provide quantitative analysis of several important parameters in the gait cycle and that it is very helpful in the evaluation and rehabilitation training of abnormal gait.

  10. Gait Disturbance as the Presenting Symptom in Young Children With Anti-NMDA Receptor Encephalitis.

    PubMed

    Yeshokumar, Anusha K; Sun, Lisa R; Klein, Jessica L; Baranano, Kristin W; Pardo, Carlos A

    2016-09-01

    This case series demonstrates a novel clinical phenotype of gait disturbance as an initial symptom in children <3 years old with anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis. Anti-NMDAR encephalitis is one of the most common causes of encephalitis in children, more common than any of the viral encephalitides and the second most common autoimmune cause after acute disseminated encephalomyelitis. Anti-NMDAR encephalitis in children often presents with disrupted speech and sleep patterns followed by progression to motor dysfunction, dyskinesias, and seizures. Because this condition can present initially with vague symptoms, diagnosis and treatment of anti-NMDAR encephalitis are often delayed. Although nearly 40% of all reported patients are <18 years old, few infants and toddlers have been reported with this disease. Four children <3 years old were diagnosed with anti-NMDAR encephalitis at our institution. Interestingly, each child presented initially with the chief concern of gait disturbance. One child presented with unsteady walking and slurred speech, suggestive of cerebellar ataxia, and 3 had inability to bear weight on a unilateral lower extremity, resulting in unsteady gait. Two of these children had seizures at the time of hospital presentation. All developed classic behavioral changes, insomnia, dyskinesias, or decreased speech immediately before or during hospitalization. When seen in the setting of other neurologic abnormalities, gait disturbance should raise the concern for anti-NMDAR encephalitis in young children. The differential diagnosis for gait disturbance in toddlers and key features suggestive of anti-NMDAR encephalitis are reviewed. PMID:27531146

  11. Recognition using gait.

    SciTech Connect

    Koch, Mark William

    2007-09-01

    Gait or an individual's manner of walking, is one approach for recognizing people at a distance. Studies in psychophysics and medicine indicate that humans can recognize people by their gait and have found twenty-four different components to gait that taken together make it a unique signature. Besides not requiring close sensor contact, gait also does not necessarily require a cooperative subject. Using video data of people walking in different scenarios and environmental conditions we develop and test an algorithm that uses shape and motion to identify people from their gait. The algorithm uses dynamic time warping to match stored templates against an unknown sequence of silhouettes extracted from a person walking. While results under similar constraints and conditions are very good, the algorithm quickly degrades with varying conditions such as surface and clothing.

  12. Gait Analysis Laboratory

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Complete motion analysis laboratory has evolved out of analyzing walking patterns of crippled children at Stanford Children's Hospital. Data is collected by placing tiny electrical sensors over muscle groups of child's legs and inserting step-sensing switches in soles of shoes. Miniature radio transmitters send signals to receiver for continuous recording of abnormal walking pattern. Engineers are working to apply space electronics miniaturization techniques to reduce size and weight of telemetry system further as well as striving to increase signal bandwidth so analysis can be performed faster and more accurately using a mini-computer.

  13. Summary measures for clinical gait analysis: a literature review.

    PubMed

    Cimolin, Veronica; Galli, Manuela

    2014-04-01

    Instrumented 3D-gait analysis (3D-GA) is an important method used to obtain information that is crucial for establishing the level of functional limitation due to pathology, observing its evolution over time and evaluating rehabilitative intervention effects. However, a typical 3D-GA evaluation produces a vast amount of data, and despite its objectivity, its use is complicated, and the data interpretation is difficult. It is even more difficult to obtain an overview on patient cohorts for a comparison. Moreover, there is a growing awareness of the need for a concise index, specifically, a single measure of the 'quality' of a particular gait pattern. Several gait summary measures, which have been used in conjunction with 3D-GA, have been proposed to objectify clinical impression, quantify the degree of gait deviation from normal, stratify the severity of pathology, document the changes in gait patterns over time and evaluate interventions.

  14. Patterns of white matter diffusivity abnormalities in Leber's hereditary optic neuropathy: a tract-based spatial statistics study.

    PubMed

    Milesi, Jacopo; Rocca, Maria A; Bianchi-Marzoli, Stefania; Petrolini, Melissa; Pagani, Elisabetta; Falini, Andrea; Comi, Giancarlo; Filippi, Massimo

    2012-09-01

    Leber's hereditary optic neuropathy (LHON) is a mitochondrial disease characterized by retinal ganglion cell degeneration and optic nerve atrophy, leading to a loss of central vision. The aim of this study was to explore the topographical pattern of damage to the brain white matter (WM) tracts from patients with chronic LHON using diffusion tensor (DT) MRI and tract-based spatial statistics (TBSS). Brain dual-echo and DT MRI scans were acquired from 13 patients with chronic LHON and 25 matched controls using a 3.0 T scanner. TBSS analysis was performed using the FMRIB's Diffusion Toolbox. A complete neuro-ophthalmologic examination, including standardized automated Humphrey perimetry as well as average and temporal peripapillary retinal nerve fiber layer thickness (PRNFL) measurements, was obtained in all patients. Mean average and temporal PRNFL thicknesses were decreased significantly in LHON patients. Compared to controls, TBSS analysis revealed significant diffusivity abnormalities in these patients, which were characterized by a decreased fractional anisotropy (FA) and an increased mean diffusivity and radial diffusivity, affecting exclusively the optic tracts and optic radiations (OR). In patients, a significant correlation was found between optic tract average FA and mean visual acuity (r = 0.57, p = 0.04). In LHON patients, DT MRI reveals a microstructural alteration of the WM along the entire visual pathways, with a sparing of the other main WM tracts of the brain. Damage to the OR may be secondary either to trans-synaptic degeneration, which in turn is due to neuroaxonal loss in the retina and optic nerve, or to local mitochondrial dysfunction.

  15. Dietary intake, food pattern, and abnormal blood glucose status of middle-aged adults: a cross-sectional community-based study in Myanmar

    PubMed Central

    Hlaing, Hlaing Hlaing; Liabsuetrakul, Tippawan

    2016-01-01

    Background Lifestyle changes, particularly dietary intake, had resulted in increasing trends of type-2 diabetes mellitus worldwide. However, dietary intake is diverse across country contexts. This study aimed to compare the dietary intake, food patterns, and blood glucose among middle-aged adults living in urban and suburban areas in Mandalay city, Myanmar, and explore their relationships. Methods A cross-sectional community-based study was conducted during June–November 2014. Adults aged 35–64 were randomly selected and requested to record all food they ate in a 4-day diary. Fasting and 2-hour postprandial blood glucose values were measured over two consecutive days. Dietary intakes were calculated in terms of energy, macronutrients, glycemic index, and glycemic load, and food patterns were identified by factor analysis. The relationships between food pattern, dietary intake, and blood glucose were assessed. Results Of 440 participants, dietary intake between urban and suburban residents was significantly different. Six food patterns were identified. There was no difference in fasting and 2-hour postprandial blood glucose between urban and suburban residents, but a strong correlation between fasting blood glucose and 2-hour postprandial blood glucose was found (correlation coefficient=0.8). Identification of abnormal blood glucose status using original fasting and converted 2-hour postprandial values showed substantial agreement (prevalence-adjusted bias-adjusted Kappa=0.8). Relationships between food patterns and blood glucose or abnormal blood glucose status were not found. Conclusion Food patterns were associated with dietary intake, not with abnormal blood glucose status. Two-hour postprandial blood glucose was highly correlated with fasting blood glucose and may be used for identifying abnormal blood glucose status. PMID:27150795

  16. Locomotor patterns in cerebellar ataxia.

    PubMed

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

    2014-12-01

    Several studies have demonstrated how cerebellar ataxia (CA) affects gait, resulting in deficits in multijoint coordination and stability. Nevertheless, how lesions of cerebellum influence the locomotor muscle pattern generation is still unclear. To better understand the effects of CA on locomotor output, here we investigated the idiosyncratic features of the spatiotemporal structure of leg muscle activity and impairments in the biomechanics of CA gait. To this end, we recorded the electromyographic (EMG) activity of 12 unilateral lower limb muscles and analyzed kinematic and kinetic parameters of 19 ataxic patients and 20 age-matched healthy subjects during overground walking. Neuromuscular control of gait in CA was characterized by a considerable widening of EMG bursts and significant temporal shifts in the center of activity due to overall enhanced muscle activation between late swing and mid-stance. Patients also demonstrated significant changes in the intersegmental coordination, an abnormal transient in the vertical ground reaction force and instability of limb loading at heel strike. The observed abnormalities in EMG patterns and foot loading correlated with the severity of pathology [International Cooperative Ataxia Rating Scale (ICARS), a clinical ataxia scale] and the changes in the biomechanical output. The findings provide new insights into the physiological role of cerebellum in optimizing the duration of muscle activity bursts and the control of appropriate foot loading during locomotion.

  17. The relationship between clinical measurements and gait analysis data in children with cerebral palsy.

    PubMed

    Domagalska, Małgorzata; Szopa, Andrzej; Syczewska, Małgorzata; Pietraszek, Stanisław; Kidoń, Zenon; Onik, Grzegorz

    2013-09-01

    Spasticity is a common impairment that interferes with motor function (particularly gait pattern) in children with cerebral palsy (CP). Gait analysis and clinical measurements are equally important in evaluating and treating gait disorders in children with CP. This study aimed to explore the relationship between the spasticity of lower extremity muscles and deviations from the normal gait pattern in children with CP. Thirty-six children with spastic CP (18 with spastic hemiplegia [HS] and 18 with spastic diplegia [DS]), ranging in age from 7 to 12 years, participated in the study. The children were classified as level I (n=24) or level II (n=12) according to the Gross Motor Function Classification System. Spasticity levels were evaluated with the Dynamic Evaluation of Range of Motion (DAROM) using the accelerometer-based system, and gait patterns were evaluated with a three dimensional gait analysis using the Zebris system (Isny, Germany). The Gillette Gait Index (GGI) was calculated from the gait data. The results show that gait pathology in children with CP does not depend on the static and dynamic contractures of hip and knee flexors. Although significant correlations were observed for a few clinical measures with the gait data (GGI), the correlation coefficients were low. Only the spasticity of rectus femoris showed a fair to moderate correlation with GGI. In conclusion, the results indicate the independence of the clinical evaluation and gait pattern and support the view that both factors provide important information about the functional problems of children with CP.

  18. Gait transitions during unrestrained locomotion in dogs.

    PubMed

    Blaszczyk, J W

    2001-04-01

    Gait transitions during long distance, unrestrained locomotion were studied in 22 mongrel dogs. Spatial and temporal limb movement parameters were collected and the phase relationships between limb movements based upon a 2-dimensional (2-D) gait diagram were computed. During most of the trials, the dogs trotted within a relatively narrow velocity range. Gait transitions were observed during radical changes of the movement velocity. In most cases the gait switches were abrupt and completed within 2 strides of the gait cycle. The dogs walked, depending on the animal size, within the upper velocity range of 0.93-1.21 m/s. Most of the walk-trot transitions were observed within this range. All of them had a typical pattern that involved changes of the phase shift between diagonal limb movements from 0.31 +/- 0.02 (a typical value for a walking dog) down to 0.02 +/- 0.03. These changes appeared abruptly within one stride cycle for each diagonal pair of limbs; therefore, the transition was completed in 2 strides of the gait cycle. The switch involved momentary shortening of the hindlimb amplitudes. During the next gait cycle, all limb movement amplitudes were reduced with a concomitant increase in limb movement frequencies. In contrast to the clear border between the symmetrical gaits, the dogs switched to gallop at any speed within the trot range (most frequently between 1.5-2.6 m/s). The transitions were usually completed within one stride of the diagonal limbs. In most cases, the switch from trot to gallop had a similar pattern; while maintaining synchronous movement of one diagonal pair of limbs, the other pair movement control was modified accordingly. The typical transition pattern involved the shortening of the swing phase in the front limb with simultaneous lengthening of the swing phase in the diagonal hindlimb. These transient modifications had their equivalent in the analogous limb movement amplitude changes. A mirror-image pattern of phase changes was observed

  19. THE INFLUENCE OF LATERALITY ON DIFFERENT PATTERNS OF ASYMMETRICAL FOOT PRESSURE AND MUSCLE ACTIVATION DURING A GAIT CYCLE IN MANUAL PUSHING.

    PubMed

    Sanjaya, Kadek Heri; Lee, Soomin; Shimomura, Yoshihiro; Katsuura, Tetsuo

    2014-12-01

    This study investigated laterality of manual pushing during a gait cycle by measuring pushing force, muscular activation and foot pressure. Subjects were 17 healthy young adult males; (11 right-handed [RH], and 6 left-handed [LH]). They pushed a force plate while walking on a treadmill at 1.5, 3, and 4 km/h. Electromyogram (EMG) data were collected bilaterally from the tibialis anterior, soleus, lumbar erector spinae and triceps brachii. To measure foot pressure, ten pressure sensors were attached bilaterally on five points of the sole. Symmetry assessment was performed by comparing bilateral data and cross-correlation function (CCF). Gait cycle duration was found to be symmetrical in all conditions. LH subjects demonstrated asymmetry in calcaneus contact duration to control ankle flexion, whereas RH were symmetrical. Velocity affected tibialis anterior muscle time lag and soleus muscle CCF coefficients, mainly in LH. We found that triceps brachii muscle CCF coefficients in LH subjects were affected by increasing velocity. Results indicated that LH and RH did not mirror each other, since both had distinct characteristics. Furthermore these asymmetries were not strictly associated with the preferred side, indicating that generalisation of preferred side to whole-body coordination should be avoided, since we could not separate one side from the other.

  20. Trunk sway during walking among older adults: norms and correlation with gait velocity.

    PubMed

    Lee, Se Won; Verghese, Joe; Holtzer, Roee; Mahoney, Jeannette R; Oh-Park, Mooyeon

    2014-09-01

    The aim of this study was to establish quantitative norms for trunk sway during walking for older male and female ambulatory adults at different age groups (65-70, 71-75, 76-80, ≥81). We also assessed the relationship between dynamic trunk sway and gait velocity in older individuals with clinically normal or abnormal gaits. Trunk sway in medio-lateral (roll) and antero-posterior (pitch) planes was measured using a body-mounted gyroscope (SwayStar) during walking on a 4.5 m long instrumented walkway. Of the 284 older adults (mean age 76.8, 54.6% women) in this sample, the mean ± SD value of roll and pitch angles were 6.0 ± 2.0° and 6.7 ± 2.2° respectively. Older women showed significantly greater trunk sway in both roll and pitch angles than older men (p<0.01). In both men and women, there was no significant association of roll angle with age although gait velocity decreased with increasing age. The relationship between roll angle and gait velocity was U-shaped for the overall sample. Among the subgroup with clinically normal gait, increased roll angle was associated with increased gait velocity (p<0.001). However, there was no significant relationship between roll angle and gait velocity among the subgroup with abnormal gait. Therefore, the relationship between medio-lateral trunk sway and gait velocity differs depending on whether gait is clinically normal. We conclude that trunk sway during walking should be interpreted with consideration of both gait velocity and presence of gait abnormality in older adults.

  1. Microarray analysis of microRNA expression patterns in the semen of infertile men with semen abnormalities.

    PubMed

    Liu, Te; Cheng, Weiwei; Gao, Yongtao; Wang, Hui; Liu, Zhixue

    2012-09-01

    MicroRNAs (miRNAs) play a crucial role in tissue development and the pathology of many diseases, however, the effects and roles of miRNAs in the development of semen abnormalities in infertile males have not yet been investigated. In this study, we analyzed and compared the miRNA expression profiles of abnormal semen from 86 infertile males with normal semen from 86 healthy males using an miRNA microarray. In total, 52 miRNAs were differentially expressed between the abnormal semen of infertile males and the normal semen of healthy males. The differential expression of selected miRNAs was validated by real time qRT-PCR and northern blotting: miR-574-5p, miR-297, miR-122, miR-1275, miR-373, miR-185 and miR-193b were upregulated (fold change>1.5, p<0.001) and miR-100, miR-512-3p, miR-16, miR-19b, miR-23b and miR-26a were downregulated (fold change<0.667, p<0.001) in the semen of infertile males with semen abnormalities. In conclusion, this study provides new insights into specific miRNAs that are associated with semen abnormalities in infertile males.

  2. Symmetrical gait descriptions

    NASA Astrophysics Data System (ADS)

    Dunajewski, Adam; Dusza, Jacek J.; Rosado Muñoz, Alfredo

    2014-11-01

    The article presents a proposal for the description of human gait as a periodic and symmetric process. Firstly, the data for researches was obtained in the Laboratory of Group SATI in the School of Engineering of University of Valencia. Then, the periodical model - Mean Double Step (MDS) was made. Finally, on the basis of MDS, the symmetrical models - Left Mean Double Step and Right Mean Double Step (LMDS and RMDS) could be created. The method of various functional extensions was used. Symmetrical gait models can be used to calculate the coefficients of asymmetry at any time or phase of the gait. In this way it is possible to create asymmetry, function which better describes human gait dysfunction. The paper also describes an algorithm for calculating symmetric models, and shows exemplary results based on the experimental data.

  3. Gait analysis using wearable sensors.

    PubMed

    Tao, Weijun; Liu, Tao; Zheng, Rencheng; Feng, Hutian

    2012-01-01

    Gait analysis using wearable sensors is an inexpensive, convenient, and efficient manner of providing useful information for multiple health-related applications. As a clinical tool applied in the rehabilitation and diagnosis of medical conditions and sport activities, gait analysis using wearable sensors shows great prospects. The current paper reviews available wearable sensors and ambulatory gait analysis methods based on the various wearable sensors. After an introduction of the gait phases, the principles and features of wearable sensors used in gait analysis are provided. The gait analysis methods based on wearable sensors is divided into gait kinematics, gait kinetics, and electromyography. Studies on the current methods are reviewed, and applications in sports, rehabilitation, and clinical diagnosis are summarized separately. With the development of sensor technology and the analysis method, gait analysis using wearable sensors is expected to play an increasingly important role in clinical applications.

  4. Gait Analysis Using Wearable Sensors

    PubMed Central

    Tao, Weijun; Liu, Tao; Zheng, Rencheng; Feng, Hutian

    2012-01-01

    Gait analysis using wearable sensors is an inexpensive, convenient, and efficient manner of providing useful information for multiple health-related applications. As a clinical tool applied in the rehabilitation and diagnosis of medical conditions and sport activities, gait analysis using wearable sensors shows great prospects. The current paper reviews available wearable sensors and ambulatory gait analysis methods based on the various wearable sensors. After an introduction of the gait phases, the principles and features of wearable sensors used in gait analysis are provided. The gait analysis methods based on wearable sensors is divided into gait kinematics, gait kinetics, and electromyography. Studies on the current methods are reviewed, and applications in sports, rehabilitation, and clinical diagnosis are summarized separately. With the development of sensor technology and the analysis method, gait analysis using wearable sensors is expected to play an increasingly important role in clinical applications. PMID:22438763

  5. Gait analysis: clinical facts.

    PubMed

    Baker, Richard; Esquenazi, Alberto; Benedetti, Maria G; Desloovere, Kaat

    2016-08-01

    Gait analysis is a well-established tool for the quantitative assessment of gait disturbances providing functional diagnosis, assessment for treatment planning, and monitoring of disease progress. There is a large volume of literature on the research use of gait analysis, but evidence on its clinical routine use supports a favorable cost-benefit ratio in a limited number of conditions. Initially gait analysis was introduced to clinical practice to improve the management of children with cerebral palsy. However, there is good evidence to extend its use to patients with various upper motor neuron diseases, and to lower limb amputation. Thereby, the methodology for properly conducting and interpreting the exam is of paramount relevance. Appropriateness of gait analysis prescription and reliability of data obtained are required in the clinical environment. This paper provides an overview on guidelines for managing a clinical gait analysis service and on the principal clinical domains of its application: cerebral palsy, stroke, traumatic brain injury and lower limb amputation. PMID:27618499

  6. Ambulatory Gait Behavior in Patients With Dementia: A Comparison With Parkinson's Disease.

    PubMed

    Yoneyama, Mitsuru; Mitoma, Hiroshi; Sanjo, Nobuo; Higuma, Maya; Terashi, Hiroo; Yokota, Takanori

    2016-08-01

    Accelerometry-based gait analysis is a promising approach in obtaining insightful information on the gait characteristics of patients with neurological disorders such as dementia and Parkinson's disease (PD). In order to improve its practical use outside the laboratory or hospital, it is required to design new metrics capable of quantifying ambulatory gait and their extraction procedures from long-term acceleration data. This paper presents a gait analysis method developed for such a purpose. Our system is based on a single trunk-mounted accelerometer and analytical algorithm for the assessment of gait behavior that may be context dependent. The algorithm consists of the detection of gait peaks from acceleration data and the analysis of multimodal patterns in the relationship between gait cycle and vertical gait acceleration. A set of six new measures can be obtained by applying the algorithm to a 24-h motion signal. To examine the performance and utility of our method, we recorded acceleration data from 13 healthy, 26 PD, and 26 mild cognitive impairment or dementia subjects. Each patient group was further classified into two, comprising 13 members each, according to the severity of the disease, and the gait behavior of the five groups was compared. We found that the normal, PD, and MCI/dementia groups show characteristic walking patterns which can be distinguished from one another by the developed gait measure set. We also examined conventional parameters such as gait acceleration, gait cycle, and gait variability, but failed to reproduce the distinct differences among the five groups. These findings suggest that the proposed gait analysis may be useful in capturing disease-specific gait features in a community setting. PMID:26372429

  7. Observational gait assessment tools in paediatrics--a systematic review.

    PubMed

    Rathinam, Chandrasekar; Bateman, Andrew; Peirson, Janet; Skinner, Jane

    2014-06-01

    Instrumented gait analysis (IGA) is an expensive technique used to objectively detect gait abnormalities in children. Observational gait assessment is considered as a cost effective alternate for IGA in regular clinical practice. This article is aimed at systematically reviewing the available paediatric gait analysis tools and examines their reliability and validity compared to IGA. This review also examines the structure of these tools, their clinical use and limitations. Articles were searched from PubMed, CINHL, AMED, BNI, EMBASE, PEDro and Cochrane library from the earliest record on the database to December 2012. Hand searches were carried out in a few journals. Studies that examined children's gait using a structured assessment tool were included and analysed for their quality, reliability and validity. Pre-established criteria were used to judge the quality of methodology and reliability and validity. Five observational gait tools for children with Cerebral Palsy (CP) and one for children with Downs Syndrome were identified. Nine studies related to children with CP were enrolled for this review. None of the tools have accomplished the level of IGA's consistency. Edinburgh Visual Gait Score (EVGS) was found to have better reliability and validity than the other tools. Very limited studies were available for most of the gait assessment tools therefore their clinical use cannot be judged based on the existing evidence. EVGS was found to have better concurrent validity and reliability and it should be considered to assess CP gait in regular practice. Future work to investigate the use of low cost technology to improve observers' accuracy of EVGS is suggested.

  8. Observational gait assessment tools in paediatrics--a systematic review.

    PubMed

    Rathinam, Chandrasekar; Bateman, Andrew; Peirson, Janet; Skinner, Jane

    2014-06-01

    Instrumented gait analysis (IGA) is an expensive technique used to objectively detect gait abnormalities in children. Observational gait assessment is considered as a cost effective alternate for IGA in regular clinical practice. This article is aimed at systematically reviewing the available paediatric gait analysis tools and examines their reliability and validity compared to IGA. This review also examines the structure of these tools, their clinical use and limitations. Articles were searched from PubMed, CINHL, AMED, BNI, EMBASE, PEDro and Cochrane library from the earliest record on the database to December 2012. Hand searches were carried out in a few journals. Studies that examined children's gait using a structured assessment tool were included and analysed for their quality, reliability and validity. Pre-established criteria were used to judge the quality of methodology and reliability and validity. Five observational gait tools for children with Cerebral Palsy (CP) and one for children with Downs Syndrome were identified. Nine studies related to children with CP were enrolled for this review. None of the tools have accomplished the level of IGA's consistency. Edinburgh Visual Gait Score (EVGS) was found to have better reliability and validity than the other tools. Very limited studies were available for most of the gait assessment tools therefore their clinical use cannot be judged based on the existing evidence. EVGS was found to have better concurrent validity and reliability and it should be considered to assess CP gait in regular practice. Future work to investigate the use of low cost technology to improve observers' accuracy of EVGS is suggested. PMID:24798609

  9. Gait changes following myofascial structural integration (Rolfing) observed in 2 children with cerebral palsy.

    PubMed

    Hansen, Alexis B; Price, Karen S; Loi, Elizabeth C; Buysse, Christina A; Jaramillo, Theresa M; Pico, Elaine L; Feldman, Heidi M

    2014-10-01

    Children with spastic cerebral palsy experience difficulty with ambulation. Structural changes in muscle and fascia may play a role in abnormal gait. Myofascial structural integration (Rolfing) is a manual therapy that manipulates muscle and soft tissues to loosen fascia layers, reposition muscles, and facilitate alignment. This study aimed to document (1) gait characteristics of 2 children with cerebral palsy and (2) effects of myofascial structural integration on their gait. Children received 3 months of weekly therapy sessions by an experienced practitioner. Gait parameters were recorded at baseline and after treatment using an electronic walkway. Children with cerebral palsy demonstrated abnormal velocity and cadence, decreased step length and single support times, and increased double support time. After treatment, both children demonstrated improvement for 3 months in cadence and double support time. The objective gait analyses demonstrated temporary improvements after myofascial structural integration in children with spastic cerebral palsy.

  10. Gait Disorder in a Cohort of Patients With Mild and Moderate Alzheimer's Disease.

    PubMed

    Castrillo, A; Olmos, L M García; Rodríguez, F; Duarte, J

    2016-05-01

    Gait disturbance results in an increase in the risk of falls in patients with Alzheimer's disease (AD). The falls are events that might be related to an increase in the number of fractures, loss of mobility, being bedridden, early institutionalization, and increased use of medication. Therefore, the reduction in the number of falls is important for the maintenance of the functional independence of the patients as well as for the prevention of sequelae resulting from those events. Alterations in the gait occur very frequently in AD, and the gait disturbance occurs relatively early in the course of the disease. This study has important implications for public health and clinical practice. This study and previous studies have reported that abnormal gait predicts greater risk of falls, dementia, institutionalization, and death. The high prevalence and incidence of abnormal gait and its association with multiple adverse outcomes in older adults require urgent attention. Our results allow us to identify the risk factors. PMID:26395024

  11. The Dercum-Muybridge Collaboration and the Study of Pathologic Gaits Using Sequential Photography.

    PubMed

    Lanska, Douglas J

    2016-01-01

    In the late 1870s and 1880s, prior to the development of movie cameras or projectors, English-American photographer Eadweard Muybridge (1830-1904) photographed sequential images of people and animals in motion, using arrays of sequentially triggered single-image cameras. In 1885, Philadelphia neurologist Francis Dercum (1856-1931) collaborated with Muybridge at the University of Pennsylvania to photograph sequential images of patients with various neurological disorders involving abnormal movements, and particularly various gait disorders, including both the sensory ataxic gait of tabes dorsalis and various spastic gaits. Dercum used tracings of sequential photographic images to plot trajectories of limbs as a way to characterize and distinguish pathologic gaits. The Dercum-Muybridge collaboration produced the first motion-picture sequences of neurological gait disorders ever filmed. These sequences and the trajectory-based studies that derived from them were a milestone in studies of pathologic gaits. PMID:26684421

  12. The Dercum-Muybridge Collaboration and the Study of Pathologic Gaits Using Sequential Photography.

    PubMed

    Lanska, Douglas J

    2016-01-01

    In the late 1870s and 1880s, prior to the development of movie cameras or projectors, English-American photographer Eadweard Muybridge (1830-1904) photographed sequential images of people and animals in motion, using arrays of sequentially triggered single-image cameras. In 1885, Philadelphia neurologist Francis Dercum (1856-1931) collaborated with Muybridge at the University of Pennsylvania to photograph sequential images of patients with various neurological disorders involving abnormal movements, and particularly various gait disorders, including both the sensory ataxic gait of tabes dorsalis and various spastic gaits. Dercum used tracings of sequential photographic images to plot trajectories of limbs as a way to characterize and distinguish pathologic gaits. The Dercum-Muybridge collaboration produced the first motion-picture sequences of neurological gait disorders ever filmed. These sequences and the trajectory-based studies that derived from them were a milestone in studies of pathologic gaits.

  13. Abnormal Fatty Acid Pattern in the Superior Temporal Gyrus Distinguishes Bipolar Disorder from Major Depression and Schizophrenia and Resembles Multiple Sclerosis

    PubMed Central

    McNamara, Robert K.; Rider, Therese; Jandacek, Ronald; Tso, Patrick

    2014-01-01

    This study investigated the fatty acid composition of the postmortem superior temporal gyrus (STG), a cortical region implicated in emotional processing, from normal controls (n=15) and patients with bipolar disorder (BD, n=15), major depressive disorder (MDD, n=15), and schizophrenia (SZ, n=15). For comparative purposes, STG fatty acid composition was determined in a separate cohort of multiple sclerosis patients (MS, n=15) and normal controls (n=15). Compared with controls, patients with BD, but not MDD or SZ, exhibited abnormal elevations in the saturated fatty acids (SFA) palmitic acid (16:0), stearic acid (18:0), the polyunsaturated fatty acids (PUFA) linoleic acid (18:2n-6), arachidonic acid (20:4n-6), and docosahexaenoic acid (22:6n-3), and reductions in the monounsaturated fatty acid (MUFA) oleic acid (18:1n-9). The total MUFA/SFA and 18:1/18:0 ratios were lower in the STG of BD patients and were inversely correlated with total PUFA composition. MS patients exhibited a pattern of fatty acid abnormalities similar to that observed in BD patients including elevated PUFA and a lower 18:1/18:0 ratio. Collectively, these data demonstrate that BD patients exhibit a pattern of fatty acid abnormalities in the STG that is not observed in MDD and SZ patients and closely resembles MS patients. PMID:24439517

  14. Texture analysis of collagen second-harmonic generation images based on local difference local binary pattern and wavelets differentiates human skin abnormal scars from normal scars

    NASA Astrophysics Data System (ADS)

    Liu, Yao; Zhu, Xiaoqin; Huang, Zufang; Cai, Jianyong; Chen, Rong; Xiong, Shuyuan; Chen, Guannan; Zeng, Haishan

    2015-01-01

    Quantitative methods for noninvasive diagnosis of scars are a challenging issue in medicine. This work aims to implement a texture analysis method for quantitatively discriminating abnormal scars from normal scars based on second-harmonic generation (SHG) images. A local difference local binary pattern (LD-LBP) operator combined with a wavelet transform was explored to extract diagnosis features from scar SHG images that were related to the alteration in collagen morphology. Based on the quantitative parameters including the homogeneity, directional and coarse features in SHG images, the scar collagen SHG images were classified into normal or abnormal scars by a support vector machine classifier in a leave-one-out cross-validation procedure. Our experiments and data analyses demonstrated apparent differences between normal and abnormal scars in terms of their morphological structure of collagen. By comparing with gray level co-occurrence matrix, wavelet transform, and combined basic local binary pattern and wavelet transform with respect to the accuracy and receiver operating characteristic analysis, the method proposed herein was demonstrated to achieve higher accuracy and more reliable classification of SHG images. This result indicated that the extracted texture features with the proposed method were effective in the classification of scars. It could provide assistance for physicians in the diagnostic process.

  15. Gait Strategy in Patients with Ehlers-Danlos Syndrome Hypermobility Type: A Kinematic and Kinetic Evaluation Using 3D Gait Analysis

    ERIC Educational Resources Information Center

    Galli, Manuela; Cimolin, Veronica; Rigoldi, Chiara; Castori, Marco; Celletti, Claudia; Albertini, Giorgio; Camerota, Filippo

    2011-01-01

    The aim of this study was to quantify the gait patterns of adults with joint hypermobility syndrome/Ehlers-Danlos syndrome (JHS/EDS-HT) hypermobility type, using Gait Analysis. We quantified the gait strategy in 12 JHS/EDS-HT adults individuals (age: 43.08 + 6.78 years) compared to 20 healthy controls (age: 37.23 plus or minus 8.91 years), in…

  16. Gait phase detection in able-bodied subjects and dementia patients.

    PubMed

    Meng, Xiaoli; Yu, Haoyong; Tham, Ming Po

    2013-01-01

    Accurate detection of gait phases allows identification of specific functional deficits at each phase of the gait cycle for motor function assessment. This paper proposes a robust gait phase detection method to identify the seven gait phases in overground walking for normal and pathologic gaits. Four inertial sensors are used to obtain knee angles, tibia angles and feet angular rate patterns in the sagittal plane. The key events segmenting the gait cycles are searched using an adaptive threshold in adaptive searching intervals to make sure it works well for different subjects with high variation in cadence and step length during walking. The subjects involved in this study are categorized into three groups: five healthy adult subjects, two healthy elderly subjects and two severe dementia patients. The experimental results have shown our method can reliably detect all gait phases for able-bodied subjects and dementia patients without subject-specific calibration.

  17. 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.

  18. Analysis of Parallel and Transverse Visual Cues on the Gait of Individuals with Idiopathic Parkinson's Disease

    ERIC Educational Resources Information Center

    de Melo Roiz, Roberta; Azevedo Cacho, Enio Walker; Cliquet, Alberto, Jr.; Barasnevicius Quagliato, Elizabeth Maria Aparecida

    2011-01-01

    Idiopathic Parkinson's disease (IPD) has been defined as a chronic progressive neurological disorder with characteristics that generate changes in gait pattern. Several studies have reported that appropriate external influences, such as visual or auditory cues may improve the gait pattern of patients with IPD. Therefore, the objective of this…

  19. Coexistence of Gait Disturbances and Chorea in Experimental Huntington's Disease.

    PubMed

    Casaca-Carreira, João; Temel, Yasin; van Zelst, Marloes; Jahanshahi, Ali

    2015-01-01

    Huntington's disease (HD) is an autosomal dominant neurodegenerative disease caused by an expanded CAG repeat. The clinical features are progressive motor dysfunction, cognitive deterioration, and psychiatric disturbances. Unpredictable choreic movements, among the most characteristic hallmarks, may contribute to gait disturbances and loss of balance in HD individuals. In this study, we aimed to investigate and characterize the gait abnormalities and choreic movements in a transgenic rat model of HD (tgHD). TgHD presents typical neuropathological, neurophysiological, and behavioral aspects mimicking some of the key features of human HD and is the only described experimental model for HD that exhibits choreiform movements. We used the Catwalk, with emphasis on static and dynamic gait parameters, to test the hypothesis that at symptomatic age (9 months) the dynamic measures of gait in HD are altered and coexist with choreiform movements. Our results showed that the dynamic parameters seem to be more affected than static parameters at this age in tgHD rats. The number of steps and step cycles and swing speed of the paws were increased in tgHD rat in comparison to wild-type controls. Our study demonstrates that gait abnormalities coexist with chorea rather than being caused by it. These symptoms may originate from distinct networks in the basal ganglia and downstream connections. PMID:26063966

  20. DNA methylation patterns in tissues from mid-gestation bovine foetuses produced by somatic cell nuclear transfer show subtle abnormalities in nuclear reprogramming

    PubMed Central

    2010-01-01

    Background Cloning of cattle by somatic cell nuclear transfer (SCNT) is associated with a high incidence of pregnancy failure characterized by abnormal placental and foetal development. These abnormalities are thought to be due, in part, to incomplete re-setting of the epigenetic state of DNA in the donor somatic cell nucleus to a state that is capable of driving embryonic and foetal development to completion. Here, we tested the hypothesis that DNA methylation patterns were not appropriately established during nuclear reprogramming following SCNT. A panel of imprinted, non-imprinted genes and satellite repeat sequences was examined in tissues collected from viable and failing mid-gestation SCNT foetuses and compared with similar tissues from gestation-matched normal foetuses generated by artificial insemination (AI). Results Most of the genomic regions examined in tissues from viable and failing SCNT foetuses had DNA methylation patterns similar to those in comparable tissues from AI controls. However, statistically significant differences were found between SCNT and AI at specific CpG sites in some regions of the genome, particularly those associated with SNRPN and KCNQ1OT1, which tended to be hypomethylated in SCNT tissues. There was a high degree of variation between individuals in methylation levels at almost every CpG site in these two regions, even in AI controls. In other genomic regions, methylation levels at specific CpG sites were tightly controlled with little variation between individuals. Only one site (HAND1) showed a tissue-specific pattern of DNA methylation. Overall, DNA methylation patterns in tissues of failing foetuses were similar to apparently viable SCNT foetuses, although there were individuals showing extreme deviant patterns. Conclusion These results show that SCNT foetuses that had developed to mid-gestation had largely undergone nuclear reprogramming and that the epigenetic signature at this stage was not a good predictor of whether the

  1. Kinetic Gait Analysis Using a Low-Cost Insole.

    PubMed

    Howell, Adam M; Kobayashi, Toshiki; Hayes, Heather A; Foreman, K Bo; Bamberg, Stacy J Morris

    2013-12-01

    Abnormal gait caused by stroke or other pathological reasons can greatly impact the life of an individual. Being able to measure and analyze that gait is often critical for rehabilitation. Motion analysis labs and many current methods of gait analysis are expensive and inaccessible to most individuals. The low-cost, wearable, and wireless insole-based gait analysis system in this study provides kinetic measurements of gait by using low-cost force sensitive resistors. This paper describes the design and fabrication of the insole and its evaluation in six control subjects and four hemiplegic stroke subjects. Subject-specific linear regression models were used to determine ground reaction force plus moments corresponding to ankle dorsiflexion/plantarflexion, knee flexion/extension, and knee abduction/adduction. Comparison with data simultaneously collected from a clinical motion analysis laboratory demonstrated that the insole results for ground reaction force and ankle moment were highly correlated (all >0.95) for all subjects, while the two knee moments were less strongly correlated (generally >0.80). This provides a means of cost-effective and efficient healthcare delivery of mobile gait analysis that can be used anywhere from large clinics to an individual's home.

  2. Low-resolution gait recognition.

    PubMed

    Zhang, Junping; Pu, Jian; Chen, Changyou; Fleischer, Rudolf

    2010-08-01

    Unlike other biometric authentication methods, gait recognition is noninvasive and effective from a distance. However, the performance of gait recognition will suffer in the low-resolution (LR) case. Furthermore, when gait sequences are projected onto a nonoptimal low-dimensional subspace to reduce the data complexity, the performance of gait recognition will also decline. To deal with these two issues, we propose a new algorithm called superresolution with manifold sampling and backprojection (SRMS), which learns the high-resolution (HR) counterparts of LR test images from a collection of HR/LR training gait image patch pairs. Then, we incorporate SRMS into a new algorithm called multilinear tensor-based learning without tuning parameters (MTP) for LR gait recognition. Our contributions include the following: 1) With manifold sampling, the redundancy of gait image patches is remarkably decreased; thus, the superresolution procedure is more efficient and reasonable. 2) Backprojection guarantees that the learned HR gait images and the corresponding LR gait images can be more consistent. 3) The optimal subspace dimension for dimension reduction is automatically determined without introducing extra parameters. 4) Theoretical analysis of the algorithm shows that MTP converges. Experiments on the USF human gait database and the CASIA gait database show the increased efficiency of the proposed algorithm, compared with previous algorithms. PMID:20199936

  3. Gait generation and control in a climbing hexapod robot

    NASA Astrophysics Data System (ADS)

    Rizzi, A. A.; Haynes, G. C.; Full, R. J.; Koditschek, D. E.

    2006-05-01

    We discuss the gait generation and control architecture of a bioinspired climbing robot that presently climbs a variety of vertical surfaces, including carpet, cork and a growing range of stucco-like surfaces in the quasi-static regime. The initial version of the robot utilizes a collection of gaits (cyclic feed-forward motion patterns) to locomote over these surfaces, with each gait tuned for a specific surface and set of operating conditions. The need for more flexibility in gait specification (e.g., adjusting number of feet on the ground), more intricate shaping of workspace motions (e.g., shaping the details of the foot attachment and detachment trajectories), and the need to encode gait "transitions" (e.g., tripod to pentapod gait structure) has led us to separate this trajectory generation scheme into the functional composition of a phase assigning transformation of the "clock space" (the six dimensional torus) followed by a map from phase into leg joints that decouples the geometric details of a particular gait. This decomposition also supports the introduction of sensory feedback to allow recovery from unexpected event and to adapt to changing surface geometries.

  4. A Portable Gait Asymmetry Rehabilitation System for Individuals with Stroke Using a Vibrotactile Feedback.

    PubMed

    Afzal, Muhammad Raheel; Oh, Min-Kyun; Lee, Chang-Hee; Park, Young Sook; Yoon, Jungwon

    2015-01-01

    Gait asymmetry caused by hemiparesis results in reduced gait efficiency and reduced activity levels. In this paper, a portable rehabilitation device is proposed that can serve as a tool in diagnosing gait abnormalities in individuals with stroke and has the capability of providing vibration feedback to help compensate for the asymmetric gait. Force-sensitive resistor (FSR) based insoles are used to detect ground contact and estimate stance time. A controller (Arduino) provides different vibration feedback based on the gait phase measurement. It also allows wireless interaction with a personal computer (PC) workstation using the XBee transceiver module, featuring data logging capabilities for subsequent analysis. Walking trials conducted with healthy young subjects allowed us to observe that the system can influence abnormality in the gait. The results of trials showed that a vibration cue based on temporal information was more effective than intensity information. With clinical experiments conducted for individuals with stroke, significant improvement in gait symmetry was observed with minimal disturbance caused to the balance and gait speed as an effect of the biofeedback. Future studies of the long-term rehabilitation effects of the proposed system and further improvements to the system will result in an inexpensive, easy-to-use, and effective rehabilitation device.

  5. A Portable Gait Asymmetry Rehabilitation System for Individuals with Stroke Using a Vibrotactile Feedback

    PubMed Central

    Afzal, Muhammad Raheel; Oh, Min-Kyun; Lee, Chang-Hee; Park, Young Sook; Yoon, Jungwon

    2015-01-01

    Gait asymmetry caused by hemiparesis results in reduced gait efficiency and reduced activity levels. In this paper, a portable rehabilitation device is proposed that can serve as a tool in diagnosing gait abnormalities in individuals with stroke and has the capability of providing vibration feedback to help compensate for the asymmetric gait. Force-sensitive resistor (FSR) based insoles are used to detect ground contact and estimate stance time. A controller (Arduino) provides different vibration feedback based on the gait phase measurement. It also allows wireless interaction with a personal computer (PC) workstation using the XBee transceiver module, featuring data logging capabilities for subsequent analysis. Walking trials conducted with healthy young subjects allowed us to observe that the system can influence abnormality in the gait. The results of trials showed that a vibration cue based on temporal information was more effective than intensity information. With clinical experiments conducted for individuals with stroke, significant improvement in gait symmetry was observed with minimal disturbance caused to the balance and gait speed as an effect of the biofeedback. Future studies of the long-term rehabilitation effects of the proposed system and further improvements to the system will result in an inexpensive, easy-to-use, and effective rehabilitation device. PMID:26161398

  6. A Portable Gait Asymmetry Rehabilitation System for Individuals with Stroke Using a Vibrotactile Feedback.

    PubMed

    Afzal, Muhammad Raheel; Oh, Min-Kyun; Lee, Chang-Hee; Park, Young Sook; Yoon, Jungwon

    2015-01-01

    Gait asymmetry caused by hemiparesis results in reduced gait efficiency and reduced activity levels. In this paper, a portable rehabilitation device is proposed that can serve as a tool in diagnosing gait abnormalities in individuals with stroke and has the capability of providing vibration feedback to help compensate for the asymmetric gait. Force-sensitive resistor (FSR) based insoles are used to detect ground contact and estimate stance time. A controller (Arduino) provides different vibration feedback based on the gait phase measurement. It also allows wireless interaction with a personal computer (PC) workstation using the XBee transceiver module, featuring data logging capabilities for subsequent analysis. Walking trials conducted with healthy young subjects allowed us to observe that the system can influence abnormality in the gait. The results of trials showed that a vibration cue based on temporal information was more effective than intensity information. With clinical experiments conducted for individuals with stroke, significant improvement in gait symmetry was observed with minimal disturbance caused to the balance and gait speed as an effect of the biofeedback. Future studies of the long-term rehabilitation effects of the proposed system and further improvements to the system will result in an inexpensive, easy-to-use, and effective rehabilitation device. PMID:26161398

  7. The integrative role of the pedunculopontine nucleus in human gait.

    PubMed

    Lau, Brian; Welter, Marie-Laure; Belaid, Hayat; Fernandez Vidal, Sara; Bardinet, Eric; Grabli, David; Karachi, Carine

    2015-05-01

    The brainstem pedunculopontine nucleus has a likely, although unclear, role in gait control, and is a potential deep brain stimulation target for treating resistant gait disorders. These disorders are a major therapeutic challenge for the ageing population, especially in Parkinson's disease where gait and balance disorders can become resistant to both dopaminergic medication and subthalamic nucleus stimulation. Here, we present electrophysiological evidence that the pedunculopontine and subthalamic nuclei are involved in distinct aspects of gait using a locomotor imagery task in 14 patients with Parkinson's disease undergoing surgery for the implantation of pedunculopontine or subthalamic nuclei deep brain stimulation electrodes. We performed electrophysiological recordings in two phases, once during surgery, and again several days after surgery in a subset of patients. The majority of pedunculopontine nucleus neurons (57%) recorded intrasurgically exhibited changes in activity related to different task components, with 29% modulated during visual stimulation, 41% modulated during voluntary hand movement, and 49% modulated during imaginary gait. Pedunculopontine nucleus local field potentials recorded post-surgically were modulated in the beta and gamma bands during visual and motor events, and we observed alpha and beta band synchronization that was sustained for the duration of imaginary gait and spatially localized within the pedunculopontine nucleus. In contrast, significantly fewer subthalamic nucleus neurons (27%) recorded intrasurgically were modulated during the locomotor imagery, with most increasing or decreasing activity phasically during the hand movement that initiated or terminated imaginary gait. Our data support the hypothesis that the pedunculopontine nucleus influences gait control in manners extending beyond simply driving pattern generation. In contrast, the subthalamic nucleus seems to control movement execution that is not likely to be gait

  8. Statistical method for prediction of gait kinematics with Gaussian process regression.

    PubMed

    Yun, Youngmok; Kim, Hyun-Chul; Shin, Sung Yul; Lee, Junwon; Deshpande, Ashish D; Kim, Changhwan

    2014-01-01

    We propose a novel methodology for predicting human gait pattern kinematics based on a statistical and stochastic approach using a method called Gaussian process regression (GPR). We selected 14 body parameters that significantly affect the gait pattern and 14 joint motions that represent gait kinematics. The body parameter and gait kinematics data were recorded from 113 subjects by anthropometric measurements and a motion capture system. We generated a regression model with GPR for gait pattern prediction and built a stochastic function mapping from body parameters to gait kinematics based on the database and GPR, and validated the model with a cross validation method. The function can not only produce trajectories for the joint motions associated with gait kinematics, but can also estimate the associated uncertainties. Our approach results in a novel, low-cost and subject-specific method for predicting gait kinematics with only the subject's body parameters as the necessary input, and also enables a comprehensive understanding of the correlation and uncertainty between body parameters and gait kinematics. PMID:24211221

  9. Histopathological pattern of gonads in cases of sex abnormalities in dogs: An attempt of morphological evaluation involving potential for neoplasia.

    PubMed

    Dzimira, Stanislaw; Nizanski, Wojciech; Ochota, Malgorzata; Madej, Janusz A

    2015-10-01

    Disturbances in sex differentiation (DSD - disorder of sexual development) may result from disturbances in sex chromosomes or a disturbed development of gonads, or from genotypic disturbances. The objective of this article is to describe the histological structure of gonads in dogs showing sexual disturbances and a case of a cancer resembling gonadoblastoma in one of the animals. Among the 10 examined dogs with disturbances of sex development only a single case of a gonadoblastoma was observed. In animals with sex disturbances, similarly to humans, there exists a potential tendency for neoplastic lesions in dysgenetic gonads. As a rule, its frequency in population is confined due to the early procedure of castration of non-breeding dogs. In the present study dogs demonstrated phenotypical traits of bitches with developmental anomalies such as hyperplastic clitoris with vestigial os penis (baculum), or abnormalities in the location and structure of the vulva. The material for the study included canine gonads of various breeds, sampled from phenotypical bitches, aged 7 months to 4 years - patients of the Department of Reproduction and Clinic of Farm Animals, Faculty of Veterinary Medicine, University of Environmental and Life Sciences in Wroclaw (Poland) in years 2006-2013. The organs were surgically removed from the abdomen and sent for histopathological examination for the purpose of determining their histological structure. The 10 examined cases of altered gonads included 6 bilateral cases of testes (60%), 2 cases of bilateral ovotestis (20%), one case of co-manifestation of testis and ovotestis (10%), and a single case of a testis and a neoplastically altered gonad (gonadoblastoma) (10%).

  10. Aberrant gene expression patterns in placentomes are associated with phenotypically normal and abnormal cattle cloned by somatic cell nuclear transfer.

    PubMed

    Everts, Robin E; Chavatte-Palmer, Pascale; Razzak, Anthony; Hue, Isabelle; Green, Cheryl A; Oliveira, Rosane; Vignon, Xavier; Rodriguez-Zas, Sandra L; Tian, X Cindy; Yang, Xiangzhong; Renard, Jean-Paul; Lewin, Harris A

    2008-03-14

    Transcription profiling of placentomes derived from somatic cell nuclear transfer (SCNT, n = 20), in vitro fertilization (IVF, n = 9), and artificial insemination (AI, n = 9) at or near term development was performed to better understand why SCNT and IVF often result in placental defects, hydrops, and large offspring syndrome (LOS). Multivariate analysis of variance was used to distinguish the effects of SCNT, IVF, and AI on gene expression, taking into account the effects of parturition (term or preterm), sex of fetus, breed of dam, breed of fetus, and pathological finding in the offspring (hydrops, normal, or other abnormalities). Differential expression of 20 physiologically important genes was confirmed with quantitative PCR. The largest effect on placentome gene expression was attributable to whether placentas were collected at term or preterm (i.e., whether the collection was because of disease or to obtain stage-matched controls) followed by placentome source (AI, IVF, or SCNT). Gene expression in SCNT placentomes was dramatically different from AI (n = 336 genes; 276 >2-fold) and from IVF (n = 733 genes; 162 >2-fold) placentomes. Functional analysis of differentially expressed genes (DEG) showed that IVF has significant effects on genes associated with cellular metabolism. In contrast, DEG associated with SCNT are involved in multiple pathways, including cell cycle, cell death, and gene expression. Many DEG were shared between the gene lists for IVF and SCNT comparisons, suggesting that common pathways are affected by the embryo culture methods used for IVF and SCNT. However, the many unique gene functions and pathways affected by SCNT suggest that cloned fetuses may be starved and accumulating toxic wastes due to placental insufficiency caused by reprogramming errors. Many of these genes are candidates for hydrops and LOS.

  11. Identifying gait asymmetry using gyroscopes--a cross-correlation and Normalized Symmetry Index approach.

    PubMed

    Gouwanda, Darwin; Senanayake, S M N Arosha

    2011-03-15

    Injury to a lower limb may disrupt natural walking and cause asymmetrical gait, therefore assessing the gait asymmetry has become one of the important procedures in gait analysis. This paper proposes the use of wireless gyroscopes as a new instrument to determine gait asymmetry. It also introduces two novel approaches: normalized cross-correlations (Cc(norm)) and Normalized Symmetry Index (SI(norm)). Cc(norm) evaluates the waveform patterns generated by the lower limb in each gait cycle. SI(norm) provides indications on the timing and magnitude of the bilateral differences between the limbs while addressing the drawbacks of the conventional methods. One-way ANOVA test reveals that Cc(norm) can be considered as single value indicator that determines the gait asymmetry (p<0.01). The experiment results showed that SI(norm) in asymmetrical gait were different from normal gait. SI(norm) in asymmetrical gait were found to be approximately 20% greater than SI(norm) in normal gait during pre-swing and initial swing.

  12. Gait transition cost in humans.

    PubMed

    Usherwood, James R; Bertram, John E A

    2003-11-01

    The energetics of locomotion depend largely on speed, gait and body size. Gait selection for a given speed appears partly, but perhaps not wholly, related to metabolic cost. One cost normally omitted from considerations of locomotion efficiency is the metabolic cost of the transition between gaits. We present the first direct assessment of the metabolic cost for the walk-run/run-walk transition in humans. The average increase in metabolic cost for a step involving a transition is 1.75 times that of a mean non-transition step at a speed where metabolic power requirements are identical for walking and running. Despite this substantial increase in cost for the transition step, the metabolic cost of gait transition is unlikely to have a strong bearing on the process of gait selection as the cost of using a metabolically inappropriate gait, even for only a few steps, will dominate. PMID:14564525

  13. Agraphia with abnormal writing stroke sequences due to cerebral infarction.

    PubMed

    Maeshima, Shinichiro; Sekiguchi, Eri; Kakishita, Koji; Okada, Hideo; Okita, Ryuji; Ozaki, Fuminori; Moriwaki, Hiroshi

    2003-04-01

    A 65-year-old, right-handed man presented with speech and gait disturbances. He was alert and cooperative, showing mild right hemiparesis and sensory disturbance. Spontaneous speech was fluent; object naming, word fluency and reading were fully preserved. Sentence repetition and verbal comprehension were mildly impaired. Writing was slow, hesitant and difficult for both spontaneous writing and dictation. Copying was better, although he had some difficulty in copying letters and also complex figures. Sequences of strokes in forming written characters were abnormal; strokes were formed by piecing together several fragments. Computed tomography and magnetic resonance imaging showed a subcortical infarct in the left frontoparietal region. Characteristics of agraphia resembled 'apractic agraphia' and agraphia may have resulted largely from loss or unavailability of the memory of motor patterns necessary for writing letters.

  14. Expression of ERα and PR in Various Morphological Patterns of Abnormal Uterine Bleeding-Endometrial causes in Reproductive Age Group

    PubMed Central

    Singh, Pallavi; Chaurasia, Amrita; Dhingra, Vishal; Misra, Vatsala

    2016-01-01

    Introduction Abnormal Uterine Bleeding (AUB) is most common gynaecological problem but its management is not well defined. So FIGO/PALMCOEIN classification was developed to provide clear management options as treatment is different in PALM and AUB-E group. FIGO/PALM-COEIN classification and immunohistochemistry with ERα and PR expression in AUB-E group will be helpful in management of these patients, thus preventing surgical interventions. Aim To study histomorphological classification according to FIGO/PALM-COEIN classification in patients presenting with AUB into PALM and AUB-E group. To study the receptor expression of ERα and PR in AUB-E group. Materials and Methods This cross sectional study was performed in patients presenting with AUB in reproductive age group (15-45 years). Six hundred endometrial specimens were stained with H&E for histolomorphological examination and classified as per FIGO/PALM-COEIN classification of AUB in non-gravid women in reproductive age group. Fifty endometrial biopsies were of pregnancy and pregnancy related complications and were excluded from study. A total of 550 samples were evaluated in present study. IHC for quantification of ERα and PR expression was carried out in AUB-E (100) cases and control group endometrium (20) cases due to technical constraints. Statistical Analysis Unpaired student t-test was performed. p-value ≤ 0.05 was taken as critical level of significance. Results Endometrial (58.19%) (AUB-E) causes were most common cause of AUB. Most common morphology was AUB-E (Proliferative endometrium), AUB-L (Leiomyoma) and AUB-E (Secretory endometrium) respectively. Statistically significant expression of ERα and PR was found in AUB-E endometrium as compared to control group endometrium. In Non secretory/Proliferative endometrium AUB-E group. Proliferative endometrium and hyperplasia without atypia had significant expression of ERα and PR in glands and stroma when compared with proliferative phase control group

  15. Gait and balance disorders.

    PubMed

    Masdeu, Joseph C

    2016-01-01

    This chapter focuses on one of the most common types of neurologic disorders: altered walking. Walking impairment often reflects disease of the neurologic structures mediating gait, balance or, most often, both. These structures are distributed along the neuraxis. For this reason, this chapter is introduced by a brief description of the neurobiologic underpinning of walking, stressing information that is critical for imaging, namely, the anatomic representation of gait and balance mechanisms. This background is essential not only in order to direct the relevant imaging tools to the regions more likely to be affected but also to interpret correctly imaging findings that may not be related to the walking deficit object of clinical study. The chapter closes with a discussion on how to image some of the most frequent etiologies causing gait or balance impairment. However, it focuses on syndromes not already discussed in other chapters of this volume, such as Parkinson's disease and other movement disorders, already discussed in Chapter 48, or cerebellar ataxia, in Chapter 23, in the previous volume. As regards vascular disease, the spastic hemiplegia most characteristic of brain disease needs little discussion, while the less well-understood effects of microvascular disease are extensively reviewed here, together with the imaging approach. PMID:27430451

  16. Morphological abnormalities among lampreys

    USGS Publications Warehouse

    Manion, Patrick J.

    1967-01-01

    The experimental control of the sea lamprey (Petromyzon marinus) in the Great Lakes has required the collection of thousands of lampreys. Representatives of each life stage of the four species of the Lake Superior basin were examined for structural abnormalities. The most common aberration was the presence of additional tails. The accessory tails were always postanal and smaller than the normal tail. The point of origin varied; the extra tails occurred on dorsal, ventral, or lateral surfaces. Some of the extra tails were misshaped and curled, but others were normal in shape and pigment pattern. Other abnormalities in larval sea lampreys were malformed or twisted tails and bodies. The cause of the structural abnormalities is unknown. The presence of extra caudal fins could be genetically controlled, or be due to partial amputation or injury followed by abnormal regeneration. Few if any lampreys with structural abnormalities live to sexual maturity.

  17. Gait Signal Analysis with Similarity Measure

    PubMed Central

    Shin, Seungsoo

    2014-01-01

    Human gait decision was carried out with the help of similarity measure design. Gait signal was selected through hardware implementation including all in one sensor, control unit, and notebook with connector. Each gait signal was considered as high dimensional data. Therefore, high dimensional data analysis was considered via heuristic technique such as the similarity measure. Each human pattern such as walking, sitting, standing, and stepping up was obtained through experiment. By the results of the analysis, we also identified the overlapped and nonoverlapped data relation, and similarity measure analysis was also illustrated, and comparison with conventional similarity measure was also carried out. Hence, nonoverlapped data similarity analysis provided the clue to solve the similarity of high dimensional data. Considered high dimensional data analysis was designed with consideration of neighborhood information. Proposed similarity measure was applied to identify the behavior patterns of different persons, and different behaviours of the same person. Obtained analysis can be extended to organize health monitoring system for specially elderly persons. PMID:25110724

  18. Abnormal N-glycosylation pattern for brain nucleotide pyrophosphatase-5 (NPP-5) in Mecp2-mutant murine models of Rett syndrome.

    PubMed

    Cortelazzo, Alessio; De Felice, Claudio; Guerranti, Roberto; Signorini, Cinzia; Leoncini, Silvia; Pecorelli, Alessandra; Scalabrì, Francesco; Madonna, Michele; Filosa, Stefania; Della Giovampaola, Cinzia; Capone, Antonietta; Durand, Thierry; Mirasole, Cristiana; Zolla, Lello; Valacchi, Giuseppe; Ciccoli, Lucia; Guy, Jacky; D'Esposito, Maurizio; Hayek, Joussef

    2016-04-01

    Neurological disorders can be associated with protein glycosylation abnormalities. Rett syndrome is a devastating genetic brain disorder, mainly caused by de novo loss-of-function mutations in the methyl-CpG binding protein 2 (MECP2) gene. Although its pathogenesis appears to be closely associated with a redox imbalance, no information on glycosylation is available. Glycoprotein detection strategies (i.e., lectin-blotting) were applied to identify target glycosylation changes in the whole brain of Mecp2 mutant murine models of the disease. Remarkable glycosylation pattern changes for a peculiar 50kDa protein, i.e., the N-linked brain nucleotide pyrophosphatase-5 were evidenced, with decreased N-glycosylation in the presymptomatic and symptomatic mutant mice. Glycosylation changes were rescued by selected brain Mecp2 reactivation. Our findings indicate that there is a causal link between the amount of Mecp2 and the N-glycosylation of NPP-5.

  19. Locomotion gaits of a rotating cylinder pair

    NASA Astrophysics Data System (ADS)

    van Rees, Wim M.; Novati, Guido; Koumoutsakos, Petros; Mahadevan, L.

    2015-11-01

    Using 2D numerical simulations of the Navier-Stokes equations, we demonstrate that a simple pair of rotating cylinders can display a range of locomotion patterns of biological and engineering interest. Steadily counter-rotating the cylinders causes the pair to move akin to a vortex dipole for low rotation rates, but as the rotational velocity is increased the direction of motion reverses. Unsteady rotations lead to different locomotion gaits that resemble jellyfish (for in-phase rotations) and undulating swimmers (for out-of-phase rotations). The small number of parameters for this simple system allows us to systematically map the phase space of these gaits, and allows us to understand the underlying physical mechanisms using a minimal model with implications for biological locomotion and engineered analogs.

  20. Inactivation of ca10a and ca10b Genes Leads to Abnormal Embryonic Development and Alters Movement Pattern in Zebrafish

    PubMed Central

    Aspatwar, Ashok; Barker, Harlan R.; Saralahti, Anni K.; Bäuerlein, Carina A.; Ortutay, Csaba; Pan, Peiwen; Kuuslahti, Marianne; Parikka, Mataleena; Rämet, Mika; Parkkila, Seppo

    2015-01-01

    Carbonic anhydrase related proteins (CARPs) X and XI are highly conserved across species and are predominantly expressed in neural tissues. The biological role of these proteins is still an enigma. Ray-finned fish have lost the CA11 gene, but instead possess two co-orthologs of CA10. We analyzed the expression pattern of zebrafish ca10a and ca10b genes during embryonic development and in different adult tissues, and studied 61 CARP X/XI-like sequences to evaluate their phylogenetic relationship. Sequence analysis of zebrafish ca10a and ca10b reveals strongly predicted signal peptides, N-glycosylation sites, and a potential disulfide, all of which are conserved, suggesting that all of CARP X and XI are secretory proteins and potentially dimeric. RT-qPCR showed that zebrafish ca10a and ca10b genes are expressed in the brain and several other tissues throughout the development of zebrafish. Antisense morpholino mediated knockdown of ca10a and ca10b showed developmental delay with a high rate of mortality in larvae. Zebrafish morphants showed curved body, pericardial edema, and abnormalities in the head and eye, and there was increased apoptotic cell death in the brain region. Swim pattern showed abnormal movement in morphant zebrafish larvae compared to the wild type larvae. The developmental phenotypes of the ca10a and ca10b morphants were confirmed by inactivating these genes with the CRISPR/Cas9 system. In conclusion, we introduce a novel zebrafish model to investigate the mechanisms of CARP Xa and CARP Xb functions. Our data indicate that CARP Xa and CARP Xb have important roles in zebrafish development and suppression of ca10a and ca10b expression in zebrafish larvae leads to a movement disorder. PMID:26218428

  1. Quality of Life and Gait in Elderly Group

    PubMed Central

    Taguchi, Carlos Kazuo; Teixeira, Jacqueline Pitanga; Alves, Lucas Vieira; Oliveira, Priscila Feliciano; Raposo, Oscar Felipe Falcão

    2015-01-01

    Introduction  The process of aging could lead to seniors being more prone to falls, which affects their quality of life. Objective  The objective of this study is to investigate the relationship between quality of life and gait in the elderly. Methods  We used World Health Organization Quality of Life-Brief (WHOQOL-Brief) Brazilian version and the Dynamic Gait Index to assess fifty-six volunteers from the northeast of Brazil. Ages ranged from 60 to 85 years. Results  The Dynamic Gait Index, which indicates the probability of falls, resulted in 36.3% of the sample presenting abnormal results. There was correlation between domain 2 (psychological) and domain 4 (environment) with domain 1(Physical) and domain 3 (Social); a negative correlation between age and Domain 2; correlation between Question 1 (How would you rate your quality of life?) and domains 1, 2, and 4 and no correlation between questions 1 and 2 (How satisfied are you with your health?). Question 2 was correlated with all of the domains. There was negative association between question 1 and falls, and a slight correlation between the Dynamic Gait Index scores and Question 1. Conclusion  The self-perception of the study group about their quality of life was either good or very good, even though a considerable percentage of individuals had suffered falls or reported gait disturbances. PMID:27413405

  2. Clinical prediction of fall risk and white matter abnormalities: a diffusion tensor imaging study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Tinetti scale is a simple clinical tool designed to predict risk of falling by focusing on gait and stance impairment in elderly persons. Gait impairment is also associated with white matter (WM) abnormalities. Objective: To test the hypothesis that elderly subjects at risk for falling, as deter...

  3. Meiotic abnormalities

    SciTech Connect

    1993-12-31

    Chapter 19, describes meiotic abnormalities. These include nondisjunction of autosomes and sex chromosomes, genetic and environmental causes of nondisjunction, misdivision of the centromere, chromosomally abnormal human sperm, male infertility, parental age, and origin of diploid gametes. 57 refs., 2 figs., 1 tab.

  4. Gait analysis in a mouse model resembling Leigh disease.

    PubMed

    de Haas, Ria; Russel, Frans G; Smeitink, Jan A

    2016-01-01

    Leigh disease (LD) is one of the clinical phenotypes of mitochondrial OXPHOS disorders and also known as sub-acute necrotizing encephalomyelopathy. The disease has an incidence of 1 in 77,000 live births. Symptoms typically begin early in life and prognosis for LD patients is poor. Currently, no clinically effective treatments are available. Suitable animal and cellular models are necessary for the understanding of the neuropathology and the development of successful new therapeutic strategies. In this study we used the Ndufs4 knockout (Ndufs4(-/-)) mouse, a model of mitochondrial complex I deficiency. Ndusf4(-/-) mice exhibit progressive neurodegeneration, which closely resemble the human LD phenotype. When dissecting behavioral abnormalities in animal models it is of great importance to apply translational tools that are clinically relevant. To distinguish gait abnormalities in patients, simple walking tests can be assessed, but in animals this is not easy. This study is the first to demonstrate automated CatWalk gait analysis in the Ndufs4(-/-) mouse model. Marked differences were noted between Ndufs4(-/-) and control mice in dynamic, static, coordination and support parameters. Variation of walking speed was significantly increased in Ndufs4(-/-) mice, suggesting hampered and uncoordinated gait. Furthermore, decreased regularity index, increased base of support and changes in support were noted in the Ndufs4(-/-) mice. Here, we report the ability of the CatWalk system to sensitively assess gait abnormalities in Ndufs4(-/-) mice. This objective gait analysis can be of great value for intervention and drug efficacy studies in animal models for mitochondrial disease.

  5. FreeWalker: a smart insole for longitudinal gait analysis.

    PubMed

    Wang, Baitong; Rajput, Kuldeep Singh; Tam, Wing-Kin; Tung, Anthony K H; Yang, Zhi

    2015-08-01

    Gait analysis is an important diagnostic measure to investigate the pattern of walking. Traditional gait analysis is generally carried out in a gait lab, with equipped force and body tracking sensors, which needs a trained medical professional to interpret the results. This procedure is tedious, expensive, and unreliable and makes it difficult to track the progress across multiple visits. In this paper, we present a smart insole called FreeWalker, which provides quantitative gait analysis outside the confinement of traditional lab, at low- cost. The insole consists of eight pressure sensors and two motion tracking sensors, i.e. 3-axis accelerometer and 3-axis gyroscope. This enables measurement of under-foot pressure distribution and motion sequences in real-time. The insole is enabled with onboard SD card as well as wireless data transmission, which help in continuous gait-cycle analysis. The data is then sent to a gateway, for analysis and interpretation of data, using a user interface where gait features are graphically displayed. We also present validation result of a subject's left foot, who was asked to perform a specific task. Experiment results show that we could achieve a data-sampling rate of over 1 KHz, transmitting data up to a distance of 20 meter and maintain a battery life of around 24 hours. Taking advantage of these features, FreeWalker can be used in various applications, like medical diagnosis, rehabilitation, sports and entertainment. PMID:26737102

  6. Temporal and spatial organization of gait-related electrocortical potentials.

    PubMed

    Knaepen, Kristel; Mierau, Andreas; Tellez, Helio Fernandez; Lefeber, Dirk; Meeusen, Romain

    2015-07-10

    To advance gait rehabilitation research it is of great importance to understand the supraspinal control of walking. In this study, the temporal and spatial characteristics of averaged electrocortical activity during treadmill walking in healthy subjects was assessed. Electroencephalography data were recorded from 32 scalp locations, averaged across trials, and related to phases of the gait cycle based on the detection of left heel strike. A characteristic temporal pattern of positive and negative potentials, similar to movement-related cortical potentials, and related to the gait cycle was observed over the cortical leg representation area. Source localization analysis revealed that mainly the primary somatosensory, somatosensory association, primary motor and cingulate cortex were activated during walking. The negative peaks of the gait-related cortical potential were associated with activity predominantly in the cingulate and prefrontal cortex, while the primary motor, primary somatosensory and somatosensory association cortex were mainly active during the positive peaks. This study identified gait-related cortical potentials during walking. The results indicate a widely distributed cortical network involved in gait control.

  7. FreeWalker: a smart insole for longitudinal gait analysis.

    PubMed

    Wang, Baitong; Rajput, Kuldeep Singh; Tam, Wing-Kin; Tung, Anthony K H; Yang, Zhi

    2015-08-01

    Gait analysis is an important diagnostic measure to investigate the pattern of walking. Traditional gait analysis is generally carried out in a gait lab, with equipped force and body tracking sensors, which needs a trained medical professional to interpret the results. This procedure is tedious, expensive, and unreliable and makes it difficult to track the progress across multiple visits. In this paper, we present a smart insole called FreeWalker, which provides quantitative gait analysis outside the confinement of traditional lab, at low- cost. The insole consists of eight pressure sensors and two motion tracking sensors, i.e. 3-axis accelerometer and 3-axis gyroscope. This enables measurement of under-foot pressure distribution and motion sequences in real-time. The insole is enabled with onboard SD card as well as wireless data transmission, which help in continuous gait-cycle analysis. The data is then sent to a gateway, for analysis and interpretation of data, using a user interface where gait features are graphically displayed. We also present validation result of a subject's left foot, who was asked to perform a specific task. Experiment results show that we could achieve a data-sampling rate of over 1 KHz, transmitting data up to a distance of 20 meter and maintain a battery life of around 24 hours. Taking advantage of these features, FreeWalker can be used in various applications, like medical diagnosis, rehabilitation, sports and entertainment.

  8. Gait Planning and Stability Control of a Quadruped Robot

    PubMed Central

    Li, Junmin; Wang, Jinge; Yang, Simon X.; Zhou, Kedong; Tang, Huijuan

    2016-01-01

    In order to realize smooth gait planning and stability control of a quadruped robot, a new controller algorithm based on CPG-ZMP (central pattern generator-zero moment point) is put forward in this paper. To generate smooth gait and shorten the adjusting time of the model oscillation system, a new CPG model controller and its gait switching strategy based on Wilson-Cowan model are presented in the paper. The control signals of knee-hip joints are obtained by the improved multi-DOF reduced order control theory. To realize stability control, the adaptive speed adjustment and gait switch are completed by the real-time computing of ZMP. Experiment results show that the quadruped robot's gaits are efficiently generated and the gait switch is smooth in the CPG control algorithm. Meanwhile, the stability of robot's movement is improved greatly with the CPG-ZMP algorithm. The algorithm in this paper has good practicability, which lays a foundation for the production of the robot prototype. PMID:27143959

  9. Knee Joint Dysfunctions That Influence Gait in Cerebrovascular Injury

    PubMed Central

    Lucareli, Paulo Roberto Garcia; Greve, Julia Maria D’Andrea

    2008-01-01

    INTRODUCTION There is still no consensus among different specialists on the subject of kinematic variation during the hemiparetic gait, including the main changes that take place during the gait cycle and whether the gait velocity changes the patterns of joint mobility. One of the most frequently discussed joints is the knee. OBJECTIVES This study aims to evaluate the variables found in the angular kinematics of knee joint, and to describe the alterations found in the hemiparetic gait resulting from cerebrovascular injury. METHODS This study included 66 adult patients of both genders with a diagnosis of either right or left hemiparesis resulting from ischemic cerebrovascular injury. All the participants underwent three-dimensional gait evaluation, an the angular kinematics of the joint knee were selected for analysis. RESULTS The results were distributed into four groups formed based on the median of the gait speed and the side of hemiparesis. CONCLUSIONS The relevant clinical characteristics included the important mechanisms of loading response in the stance, knee hyperextension in single stance, and reduction of the peak flexion and movement amplitude of the knee in the swing phase. These mechanisms should be taken into account when choosing the best treatment. We believe that the findings presented here may aid in preventing the occurrence of the problems found, and also in identifying the origin of these problems. PMID:18719753

  10. Gait Planning and Stability Control of a Quadruped Robot.

    PubMed

    Li, Junmin; Wang, Jinge; Yang, Simon X; Zhou, Kedong; Tang, Huijuan

    2016-01-01

    In order to realize smooth gait planning and stability control of a quadruped robot, a new controller algorithm based on CPG-ZMP (central pattern generator-zero moment point) is put forward in this paper. To generate smooth gait and shorten the adjusting time of the model oscillation system, a new CPG model controller and its gait switching strategy based on Wilson-Cowan model are presented in the paper. The control signals of knee-hip joints are obtained by the improved multi-DOF reduced order control theory. To realize stability control, the adaptive speed adjustment and gait switch are completed by the real-time computing of ZMP. Experiment results show that the quadruped robot's gaits are efficiently generated and the gait switch is smooth in the CPG control algorithm. Meanwhile, the stability of robot's movement is improved greatly with the CPG-ZMP algorithm. The algorithm in this paper has good practicability, which lays a foundation for the production of the robot prototype. PMID:27143959

  11. Balance and knee extensibility evaluation of hemiplegic gait using an inertial body sensor network

    PubMed Central

    2013-01-01

    Background Most hemiplegic patients have difficulties in their balance and posture control while walking because of the asymmetrical posture and the abnormal body balance. The assessment of rehabilitation of hemiplegic gait is usually made by doctors using clinical scale, but it is difficult and could not be used frequently. It is therefore needed to quantitatively analyze the characteristics of hemiplegic gait. Thus the assessment would be simple, and real-time evaluation of rehabilitation could be carried out. Methods Twenty subjects (ten hemiplegic patients, ten normal subjects) were recruited. The subjects walked straight for five meters at their self-selected comfortable speed towards a target line on the floor. Xsens MTx motion trackers were used for acquiring gestures of body segments to estimate knee joint angles and identify gait cycles. A practical method for data acquisition that does not need to obtain accurate distances between a knee joint and its corresponding sensors is presented. Results The results showed that there were significant differences between the two groups in the three nominated angle amplitudes. The mean values of balance level of each parameter in hemiplegic gait and normal gait were: 0.21 versus 0.01, 0.18 versus 0.03, and 0.92 versus 0.03, respectively. The mean values of added angles of each parameter in hemiplegic gait and normal gait were: 74.64 versus 91.31, -76.48 versus −132.4, and 6.77 versus 35.74. Conclusions It was concluded that the wearable bio-motion acquisition platform provided a practical approach that was effective in discriminating gait symptoms between hemiplegic and asymptomatic subjects. The extensibility of hemiplegic patients’ lower limbs was significantly lower than that of normal subjects, and the hemiplegic gait had worse balance level compared with normal gait. The effect of rehabilitation training of hemiplegic gait could be quantitatively analyzed. PMID:23988116

  12. Extraction of human gait signatures: an inverse kinematic approach using Groebner basis theory applied to gait cycle analysis

    NASA Astrophysics Data System (ADS)

    Barki, Anum; Kendricks, Kimberly; Tuttle, Ronald F.; Bunker, David J.; Borel, Christoph C.

    2013-05-01

    This research highlights the results obtained from applying the method of inverse kinematics, using Groebner basis theory, to the human gait cycle to extract and identify lower extremity gait signatures. The increased threat from suicide bombers and the force protection issues of today have motivated a team at Air Force Institute of Technology (AFIT) to research pattern recognition in the human gait cycle. The purpose of this research is to identify gait signatures of human subjects and distinguish between subjects carrying a load to those subjects without a load. These signatures were investigated via a model of the lower extremities based on motion capture observations, in particular, foot placement and the joint angles for subjects affected by carrying extra load on the body. The human gait cycle was captured and analyzed using a developed toolkit consisting of an inverse kinematic motion model of the lower extremity and a graphical user interface. Hip, knee, and ankle angles were analyzed to identify gait angle variance and range of motion. Female subjects exhibited the most knee angle variance and produced a proportional correlation between knee flexion and load carriage.

  13. Rhythmic auditory stimulation using a portable smart device: short-term effects on gait in chronic hemiplegic stroke patients

    PubMed Central

    Ko, Byung-Woo; Lee, Hwi-Young; Song, Won-Kyung

    2016-01-01

    [Purpose] The effects of various rhythmic auditory stimulation tempos on stroke gait pattern changes when training patients with a smartphone-based rhythmic auditory stimulation application were investigated. [Subjects and Methods] Fifteen patients with chronic stroke were included. Cadence during comfortable walking was measured (baseline). After the baseline findings were recorded, rhythmic auditory stimulation with five different tempos (i.e., −10%, −5%, 0%, +5%, and +10% change from baseline) was randomly applied. Finally, comfortable walking without rhythmic auditory stimulation was initiated to evaluate gait pattern changes. [Results] As the tempo increased, the spatiotemporal gait parameters of the stroke patients changed significantly. Gait speed, cadence, and gait cycle duration showed the greatest improvement in the +10% rhythmic auditory stimulation condition compared to baseline. After gait training with rhythmic auditory stimulation, gait speed, cadence, stride length, gait cycle duration, and step length of the affected and unaffected sides improved significantly compared to baseline. [Conclusion] Significant changes in the gait pattern of stroke patients were noted for various tempos after training with rhythmic auditory stimulation. These findings could be used to customize rehabilitative gait training for patients who experience stroke with hemiplegia. PMID:27313366

  14. Multi-scale complexity analysis of muscle coactivation during gait in children with cerebral palsy

    PubMed Central

    Tao, Wen; Zhang, Xu; Chen, Xiang; Wu, De; Zhou, Ping

    2015-01-01

    The objective of this study is to characterize complexity of lower-extremity muscle coactivation and coordination during gait in children with cerebral palsy (CP), children with typical development (TD) and healthy adults, by applying recently developed multivariate multi-scale entropy (MMSE) analysis to surface electromyographic (EMG) signals. Eleven CP children (CP group), eight TD children and seven healthy adults (considered as an entire control group) were asked to walk while surface EMG signals were collected from five thigh muscles and three lower leg muscles on each leg (16 EMG channels in total). The 16-channel surface EMG data, recorded during a series of consecutive gait cycles, were simultaneously processed by multivariate empirical mode decomposition (MEMD), to generate fully aligned data scales for subsequent MMSE analysis. In order to conduct extensive examination of muscle coactivation complexity using the MEMD-enhanced MMSE, 14 data analysis schemes were designed by varying partial muscle combinations and time durations of data segments. Both TD children and healthy adults showed almost consistent MMSE curves over multiple scales for all the 14 schemes, without any significant difference (p > 0.09). However, distinct diversity in MMSE curve was observed in the CP group when compared with the control group. There appears to be diverse neuropathological processes in CP that may affect dynamical complexity of muscle coactivation and coordination during gait. The abnormal complexity patterns emerging in the CP group can be attributed to different factors such as motor control impairments, loss of muscle couplings, and spasticity or paralysis in individual muscles. This study expands our knowledge of neuropathology of CP from a novel point of view of muscle co-activation complexity, which might be useful to derive a quantitative index for assessing muscle activation characteristics as well as motor function in CP. PMID:26257622

  15. Three-Dimensional Gait Analysis Can Shed New Light on Walking in Patients with Haemophilia

    PubMed Central

    Lobet, Sébastien; Detrembleur, Christine; Massaad, Firas; Hermans, Cedric

    2013-01-01

    In patients with haemophilia (PWH) (from Greek “blood love”), the long-term consequences of repeated haemarthrosis include cartilage damage and irreversible arthropathy, resulting in severe impairments in locomotion. Quantifying the extent of joint damage is therefore important in order to prevent disease progression and compare the efficacy of treatment strategies. Musculoskeletal impairments in PWH may stem from structural and functional abnormalities, which have traditionally been evaluated radiologically or clinically. However, these examinations are performed in a supine position (i.e., non-weight-bearing condition). We therefore suggest three-dimensional gait analysis (3DGA) as an innovative approach designed to focus on the functional component of the joint during the act of walking. This is of the utmost importance, as pain induced by weight-bearing activities influences the functional performance of the arthropathic joints significantly. This review endeavors to improve our knowledge of the biomechanical consequences of multiple arthropathies on gait pattern in adult patients with haemophilia using 3DGA. In PWH with arthropathy, the more the joint function was altered, the more the metabolic energy was consumed. 3DGA analysis could highlight the effect of an orthopedic disorder in PWH during walking. Indeed, mechanical and metabolic impairments were correlated to the progressive loss of active mobility into the joints. PMID:23766686

  16. Geometric moments for gait description

    NASA Astrophysics Data System (ADS)

    Toxqui-Quitl, C.; Morales-Batalla, V.; Padilla-Vivanco, A.; Camacho-Bello, C.

    2013-09-01

    The optical flow associated with a set of digital images of a moving individual is analyzed in order to extract a gait signature. For this, invariant Hu moments are obtained for image description. A Hu Moment History (HMH) is obtained from K frames to describe the gait signature of individuals in a video. The gait descriptors are subsequences of the HMH of variable width. Each subsequence is generated by means of genetic algorithms and used for classification in a neuronal network. The database for algorithm evaluation is MoBo, and the gait classification results are above 90% for the cases of slow and fast walking and 100% for the cases of walking with a ball and inclined walking. An optical processor is also implemented in order to obtain the descriptors of the human gait.

  17. Craniofacial Abnormalities

    MedlinePlus

    ... of the skull and face. Craniofacial abnormalities are birth defects of the face or head. Some, like cleft ... palate, are among the most common of all birth defects. Others are very rare. Most of them affect ...

  18. Chromosome Abnormalities

    MedlinePlus

    ... decade, newer techniques have been developed that allow scientists and doctors to screen for chromosomal abnormalities without using a microscope. These newer methods compare the patient's DNA to a normal DNA ...

  19. Nail abnormalities

    MedlinePlus

    Beau's lines; Fingernail abnormalities; Spoon nails; Onycholysis; Leukonychia; Koilonychia; Brittle nails ... Just like the skin, the fingernails tell a lot about your health: ... the fingernail. These lines can occur after illness, injury to ...

  20. Estimation of temporal gait parameters using Bayesian models on acceleration signals.

    PubMed

    López-Nava, I H; Muñoz-Meléndez, A; Pérez Sanpablo, A I; Alessi Montero, A; Quiñones Urióstegui, I; Núñez Carrera, L

    2016-01-01

    The purpose of this study is to develop a system capable of performing calculation of temporal gait parameters using two low-cost wireless accelerometers and artificial intelligence-based techniques as part of a larger research project for conducting human gait analysis. Ten healthy subjects of different ages participated in this study and performed controlled walking tests. Two wireless accelerometers were placed on their ankles. Raw acceleration signals were processed in order to obtain gait patterns from characteristic peaks related to steps. A Bayesian model was implemented to classify the characteristic peaks into steps or nonsteps. The acceleration signals were segmented based on gait events, such as heel strike and toe-off, of actual steps. Temporal gait parameters, such as cadence, ambulation time, step time, gait cycle time, stance and swing phase time, simple and double support time, were estimated from segmented acceleration signals. Gait data-sets were divided into two groups of ages to test Bayesian models in order to classify the characteristic peaks. The mean error obtained from calculating the temporal gait parameters was 4.6%. Bayesian models are useful techniques that can be applied to classification of gait data of subjects at different ages with promising results.

  1. Effects of walking speed on asymmetry and bilateral coordination of gait

    PubMed Central

    Plotnik, Meir; Bartsch, Ronny P.; Zeev, Aviva; Giladi, Nir; Hausdorff, Jeffery M.

    2013-01-01

    The mechanisms regulating the bilateral coordination of gait in humans are largely unknown. Our objective was to study how bilateral coordination changes as a result of gait speed modifications during over ground walking. 15 young adults wore force sensitive insoles that measured vertical forces used to determine the timing of the gait cycle events under three walking conditions (i.e., usual-walking, fast and slow). Ground reaction force impact (GRFI) associated with heel-strikes was also quantified, representing the potential contribution of sensory feedback to the regulation of gait. Gait asymmetry (GA) was quantified based on the differences between right and left swing times and the bilateral coordination of gait was assessed using the phase coordination index (PCI), a metric that quantifies the consistency and accuracy of the anti-phase stepping pattern. GA was preserved in the three different gait speeds. PCI was higher (reduced coordination) in the slow gait condition, compared to usual-walking (3.51% vs. 2.47%, respectively, p=0.002), but was not significantly affected in the fast condition. GRFI values were lower in the slow walking as compared to usual-walking and higher in the fast walking condition (p<0.001). Stepwise regression revealed that slowed gait related changes in PCI were not associated with the slowed gait related changes in GRFI. The present findings suggest that left-right anti-phase stepping is similar in normal and fast walking, but altered during slowed walking. This behavior might reflect a relative increase in attention resources required to regulate a slow gait speed, consistent with the possibility that cortical function and supraspinal input influences the bilateral coordination of gait. PMID:23680424

  2. Effects of walking speed on asymmetry and bilateral coordination of gait.

    PubMed

    Plotnik, Meir; Bartsch, Ronny P; Zeev, Aviva; Giladi, Nir; Hausdorff, Jeffery M

    2013-09-01

    The mechanisms regulating the bilateral coordination of gait in humans are largely unknown. Our objective was to study how bilateral coordination changes as a result of gait speed modifications during over ground walking. 15 young adults wore force sensitive insoles that measured vertical forces used to determine the timing of the gait cycle events under three walking conditions (i.e., usual-walking, fast and slow). Ground reaction force impact (GRFI) associated with heel-strikes was also quantified, representing the potential contribution of sensory feedback to the regulation of gait. Gait asymmetry (GA) was quantified based on the differences between right and left swing times and the bilateral coordination of gait was assessed using the phase coordination index (PCI), a metric that quantifies the consistency and accuracy of the anti-phase stepping pattern. GA was preserved in the three different gait speeds. PCI was higher (reduced coordination) in the slow gait condition, compared to usual-walking (3.51% vs. 2.47%, respectively, p=0.002), but was not significantly affected in the fast condition. GRFI values were lower in the slow walking as compared to usual-walking and higher in the fast walking condition (p<0.001). Stepwise regression revealed that slow gait related changes in PCI were not associated with the slow gait related changes in GRFI. The present findings suggest that left-right anti-phase stepping is similar in normal and fast walking, but altered during slow walking. This behavior might reflect a relative increase in attention resources required to regulate a slow gait speed, consistent with the possibility that cortical function and supraspinal input influences the bilateral coordination of gait.

  3. GAIT-ER-AID: An Expert System for Analysis of Gait with Automatic Intelligent Pre-Processing of Data

    PubMed Central

    Bontrager, EL.; Perry, J.; Bogey, R.; Gronley, J.; Barnes, L.; Bekey, G.; Kim, JW.

    1990-01-01

    This paper describes the architecture and applications of an expert system designed to identify the specific muscles responsible for a given dysfunctional gait pattern. The system consists of two parts: a data analysis expert system (DA/ES) and a gait pathology expert system (GP/ES). The DA/ES processes raw data on joint angles, foot-floor contact patterns and EMG's from relevant muscles and synthesizes them into a data frame for use by the GP/ES. Various aspects of the intelligent data pre-processing are described in detail, followed by a presentation of the GP/ES, including its structure, knowledge base, rule base, and inference engine. The inference process is clarified by careful analysis of an actual case, a patient with an equinus gait.

  4. Diffusion Tensor Imaging, White Matter lesions, the Corpus Callosum and Gait in the Elderly

    PubMed Central

    Bhadelia, Refeeque A.; Price, Lori Lyn; Tedesco, Kurtis L.; Scott, Tammy; Qiu, Wei Qiao; Patz, Samuel; Folstein, Marshal; Rosenberg, Irwin; Caplan, Louis R.; Bergethon, Peter

    2009-01-01

    Background and Purpose Gait impairment is common in the elderly, especially those with stroke and white matter hyperintensities (WMH) on conventional brain MRI. Diffusion Tensor Imaging (DTI) is more sensitive to white matter damage than conventional MRI. The relationship between DTI measures and gait has not been previously evaluated. Our purpose was to investigate the relationship between the integrity of white matter in the corpus callosum as determined by DTI and quantitative measures of gait in the elderly. Methods One hundred seventy-three participants of a community-dwelling elderly cohort had neurological and neuropsychological examinations and brain MRI. Gait function was measured by Tinetti gait (0-12), balance (0-16) and total (0-28) scores. DTI assessed Fractional Anisotropy in the genu and splenium of the corpus callosum. Conventional MRI was used to evaluate for brain infarcts and WMH volume. Results Participants with abnormal gait had low fractional anisotropy in the genu of the corpus callosum but not the splenium. Multiple regressions analyses showed an independent association between these genu abnormalities and all three Tinetti scores (p <0.001). This association remained significant after adding MRI infarcts and WMH volume to the analysis. Conclusions The independent association between quantitative measures of gait function and DTI findings shows that white matter integrity in the genu of corpus callosum is an important marker of gait in the elderly. DTI analyses of white matter tracts in brain and spinal cord may improve knowledge about the pathophysiology of gait impairment and help target clinical interventions. PMID:19797696

  5. 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

  6. Gait performance is not influenced by working memory when walking at a self-selected pace.

    PubMed

    Grubaugh, Jordan; Rhea, Christopher K

    2014-02-01

    Gait performance exhibits patterns within the stride-to-stride variability that can be indexed using detrended fluctuation analysis (DFA). Previous work employing DFA has shown that gait patterns can be influenced by constraints, such as natural aging or disease, and they are informative regarding a person's functional ability. Many activities of daily living require concurrent performance in the cognitive and gait domains; specifically working memory is commonly engaged while walking, which is considered dual-tasking. It is unknown if taxing working memory while walking influences gait performance as assessed by DFA. This study used a dual-tasking paradigm to determine if performance decrements are observed in gait or working memory when performed concurrently. Healthy young participants (N = 16) performed a working memory task (automated operation span task) and a gait task (walking at a self-selected speed on a treadmill) in single- and dual-task conditions. A second dual-task condition (reading while walking) was included to control for visual attention, but also introduced a task that taxed working memory over the long term. All trials involving gait lasted at least 10 min. Performance in the working memory task was indexed using five dependent variables (absolute score, partial score, speed error, accuracy error, and math error), while gait performance was indexed by quantifying the mean, standard deviation, and DFA α of the stride interval time series. Two multivariate analyses of variance (one for gait and one for working memory) were used to examine performance in the single- and dual-task conditions. No differences were observed in any of the gait or working memory dependent variables as a function of task condition. The results suggest the locomotor system is adaptive enough to complete a working memory task without compromising gait performance when walking at a self-selected pace.

  7. Terminology and forensic gait analysis.

    PubMed

    Birch, Ivan; Vernon, Wesley; Walker, Jeremy; Young, Maria

    2015-07-01

    The use of appropriate terminology is a fundamental aspect of forensic gait analysis. The language used in forensic gait analysis is an amalgam of that used in clinical practice, podiatric biomechanics and the wider field of biomechanics. The result can often be a lack of consistency in the language used, the definitions used and the clarity of the message given. Examples include the use of 'gait' and 'walking' as synonymous terms, confusion between 'step' and 'stride', the mixing of anatomical, positional and pathological descriptors, and inability to describe appropriately movements of major body segments such as the torso. The purpose of this paper is to share the well-established definitions of the fundamental parameters of gait, common to all professions, and advocate their use in forensic gait analysis to establish commonality. The paper provides guidance on the selection and use of appropriate terminology in the description of gait in the forensic context. This paper considers the established definitions of the terms commonly used, identifies those terms which have the potential to confuse readers, and suggests a framework of terminology which should be utilised in forensic gait analysis.

  8. Impaired gait in ankylosing spondylitis.

    PubMed

    Del Din, Silvia; Carraro, Elena; Sawacha, Zimi; Guiotto, Annamaria; Bonaldo, Lara; Masiero, Stefano; Cobelli, Claudio

    2011-07-01

    Ankylosing spondylitis (AS) is a chronic, inflammatory rheumatic disease. The spine becomes rigid from the occiput to the sacrum, leading to a stooped position. This study aims at evaluating AS subjects gait alterations. Twenty-four subjects were evaluated: 12 normal and 12 pathologic in stabilized anti-TNF-alpha treatment (mean age 49.42 (10.47), 25.44 (3.19) and mean body mass index 55.75 (3.19), 23.73 (2.7), respectively). Physical examination and gait analysis were performed. A motion capture system synchronized with two force plates was used. Three-dimensional kinematics and kinetics of trunk, pelvis, hip, knee and ankle were determined during gait. A trend towards reduction was found in gait velocity and stride length. Gait analysis results showed statistically significant alterations in the sagittal plane at each joint for AS patients (P < 0.049). Hip and knee joint extension moments showed a statistically significant reduction (P < 0.044). At the ankle joint, a decreased plantarflexion was assessed (P < 0.048) together with the absence of the heel rocker. Gait analysis, through gait alterations identification, allowed planning-specific rehabilitation intervention aimed to prevent patients' stiffness together with improve balance and avoid muscles' fatigue.

  9. A Personalized Multi-Channel FES Controller Based on Muscle Synergies to Support Gait Rehabilitation after Stroke

    PubMed Central

    Ferrante, Simona; Chia Bejarano, Noelia; Ambrosini, Emilia; Nardone, Antonio; Turcato, Anna M.; Monticone, Marco; Ferrigno, Giancarlo; Pedrocchi, Alessandra

    2016-01-01

    It has been largely suggested in neuroscience literature that to generate a vast variety of movements, the Central Nervous System (CNS) recruits a reduced set of coordinated patterns of muscle activities, defined as muscle synergies. Recent neurophysiological studies have recommended the analysis of muscle synergies to finely assess the patient's impairment, to design personalized interventions based on the specific nature of the impairment, and to evaluate the treatment outcomes. In this scope, the aim of this study was to design a personalized multi-channel functional electrical stimulation (FES) controller for gait training, integrating three novel aspects: (1) the FES strategy was based on healthy muscle synergies in order to mimic the neural solutions adopted by the CNS to generate locomotion; (2) the FES strategy was personalized according to an initial locomotion assessment of the patient and was designed to specifically activate the impaired biomechanical functions; (3) the FES strategy was mapped accurately on the altered gait kinematics providing a maximal synchronization between patient's volitional gait and stimulation patterns. The novel intervention was tested on two chronic stroke patients. They underwent a 4-week intervention consisting of 30-min sessions of FES-supported treadmill walking three times per week. The two patients were characterized by a mild gait disability (walking speed > 0.8 m/s) at baseline. However, before treatment both patients presented only three independent muscle synergies during locomotion, resembling two different gait abnormalities. After treatment, the number of extracted synergies became four and they increased their resemblance with the physiological muscle synergies, which indicated a general improvement in muscle coordination. The originally merged synergies seemed to regain their distinct role in locomotion control. The treatment benefits were more evident for one patient, who achieved a clinically important change

  10. A Personalized Multi-Channel FES Controller Based on Muscle Synergies to Support Gait Rehabilitation after Stroke

    PubMed Central

    Ferrante, Simona; Chia Bejarano, Noelia; Ambrosini, Emilia; Nardone, Antonio; Turcato, Anna M.; Monticone, Marco; Ferrigno, Giancarlo; Pedrocchi, Alessandra

    2016-01-01

    It has been largely suggested in neuroscience literature that to generate a vast variety of movements, the Central Nervous System (CNS) recruits a reduced set of coordinated patterns of muscle activities, defined as muscle synergies. Recent neurophysiological studies have recommended the analysis of muscle synergies to finely assess the patient's impairment, to design personalized interventions based on the specific nature of the impairment, and to evaluate the treatment outcomes. In this scope, the aim of this study was to design a personalized multi-channel functional electrical stimulation (FES) controller for gait training, integrating three novel aspects: (1) the FES strategy was based on healthy muscle synergies in order to mimic the neural solutions adopted by the CNS to generate locomotion; (2) the FES strategy was personalized according to an initial locomotion assessment of the patient and was designed to specifically activate the impaired biomechanical functions; (3) the FES strategy was mapped accurately on the altered gait kinematics providing a maximal synchronization between patient's volitional gait and stimulation patterns. The novel intervention was tested on two chronic stroke patients. They underwent a 4-week intervention consisting of 30-min sessions of FES-supported treadmill walking three times per week. The two patients were characterized by a mild gait disability (walking speed > 0.8 m/s) at baseline. However, before treatment both patients presented only three independent muscle synergies during locomotion, resembling two different gait abnormalities. After treatment, the number of extracted synergies became four and they increased their resemblance with the physiological muscle synergies, which indicated a general improvement in muscle coordination. The originally merged synergies seemed to regain their distinct role in locomotion control. The treatment benefits were more evident for one patient, who achieved a clinically important change

  11. Real-time knee adduction moment feedback for gait retraining through visual and tactile displays.

    PubMed

    Wheeler, Jason W; Shull, Pete B; Besier, Thor F

    2011-04-01

    The external knee adduction moment (KAM) measured during gait is an indicator of tibiofemoral joint osteoarthritis progression and various strategies have been proposed to lower it. Gait retraining has been shown to be an effective, noninvasive approach for lowering the KAM. We present a new gait retraining approach in which the KAM is fed back to subjects in real-time during ambulation. A study was conducted in which 16 healthy subjects learned to alter gait patterns to lower the KAM through visual or tactile (vibration) feedback. Participants converged on a comfortable gait in just a few minutes by using the feedback to iterate on various kinematic modifications. All subjects adopted altered gait patterns with lower KAM compared with normal ambulation (average reduction of 20.7%). Tactile and visual feedbacks were equally effective for real-time training, although subjects using tactile feedback took longer to converge on an acceptable gait. This study shows that real-time feedback of the KAM can greatly increase the effectiveness and efficiency of subject-specific gait retraining compared with conventional methods.

  12. Using three-dimensional gait data for foot/ankle orthopaedic surgery.

    PubMed

    de Vries, Gwyneth; Roy, Kevin; Chester, Victoria

    2009-01-01

    We present the case of a forty year old male who sustained a torn carotid during strenuous physical activity. This was followed by a right hemispheric stroke due to a clot associated with the carotid. Upon recovery, the patient's gait was characterized as hemiparetic with a stiff-knee pattern, a fixed flexion deformity of the toe flexors, and a hindfoot varus. Based on clinical exams and radiographs, the surgical treatment plan was established and consisted of correction of the forefoot deformities, possible hamstrings lengthening, and tendon transfer of the posterior tibial tendon to the dorsolateral foot. To aid in surgical planning, a three-dimensional gait analysis was conducted using a state-of-the-art motion capture system. Data from this analysis provided insight into the pathomechanics of the patient's gait pattern. A forefoot driven hindfoot varus was evident from the presurgical data and the tendon transfer procedure was deemed unnecessary. A computer was used in the OR to provide surgeons with animations of the patient's gait and graphical results as needed. A second gait analysis was conducted 6 weeks post surgery, shortly after cast removal. Post-surgical gait data showed improved foot segment orientation and position. Motion capture data provides clinicians with detailed information on the multisegment kinematics of foot motion during gait, before and during surgery. Further, treatment effectiveness can be evaluated by repeating gait analyses after recovery. PMID:19997521

  13. Gait function in high-functioning autism and Asperger's disorder : evidence for basal-ganglia and cerebellar involvement?

    PubMed

    Rinehart, Nicole J; Tonge, Bruce J; Bradshaw, John L; Iansek, Robert; Enticott, Peter G; McGinley, Jenny

    2006-08-01

    Gait abnormalities have been widely reported in individuals with autism and Asperger's disorder. There is controversy as to whether the cerebellum or the basal-ganglia frontostriatal regions underpin these abnormalities. This is the first direct comparison of gait and upper-body postural features in autism and Asperger's disorder. Clinical and control groups were matched according to age, height, weight, performance, and full scale IQ. Consistent with Hallet's (1993) cerebellar-gait hypothesis, the autistic group showed significantly increased stride-length variability in their gait in comparison to control and Asperger's disorder participants. No quantitative gait deficits were found for the Asperger's disorder group. In support of Damasio and Maurer's (1982) basal-ganglia frontostriatal-gait hypothesis, both clinical groups were rated as showing abnormal arm posturing, however, only the Asperger's group were rated as significantly different from controls in terms of head and trunk posturing. While DSM-IV-TR suggests that Asperger's disorder, but not autism, is associated with motoric clumsiness, our data suggest that both clinical groups are uncoordinated and lacking in motor smoothness. Gait differences in autism and Asperger's disorder were suggested to reflect differential involvement of the cerebellum, with commonalities reflecting similar involvement of the basal-ganglia frontostriatal region.

  14. The internal auditory clock: what can evoked potentials reveal about the analysis of temporal sound patterns, and abnormal states of consciousness?

    PubMed

    Jones, S J

    2002-09-01

    internal "clocks"? Abnormal mismatch potentials may provide a manifestation of a disordered auditory time-sense, sometimes being abolished in comatose patients while the C-potentials and similar responses to the onset of tones are preserved. Both C- and M-potentials were usually found to be preserved, however, in patients who had emerged from coma and were capable of discriminating sounds. Substantially intact responses were also recorded from three patients who were functionally in a "vegetative" state. The C- and M-potentials were once again dissociated in a group of patients with multiple sclerosis, only the mismatch potentials being found to be significantly delayed. This subclinical impairment of a memory-based process responsible for the detection of change in temporal sound patterns may be related to defects in other memory domains such as working memory. PMID:12448181

  15. Chopart prosthesis and semirigid foot orthosis in traumatic forefoot amputation. Comparative gait analysis.

    PubMed

    Hirsch, G; McBride, M E; Murray, D D; Sanderson, D J; Dukes, I; Menard, M R

    1996-01-01

    Gait was analyzed in seven otherwise healthy males at least 11 mo after they had recovered from a traumatic unilateral transmetatarsal amputation incurred during the course of their usual occupation. All seven were fitted with a semirigid foot orthosis. Four were also fitted with a Chopart prosthesis. Gait was evaluated with forceplate measurements of ground reaction force during free walking, by clinical observation of such ambulation on videotape, and by the subjective impression of the men as obtained by a questionnaire. In all men, with unmodified footwear, with the orthosis, and with the prosthesis, the forceplate data showed an abnormal pattern characterized by reduced stance duration and deficient forward propulsion on the amputated side. The abnormality and asymmetry of ground-reaction forces were less with greater preserved stump length and for a given stump length were with the above-ankle concept (Chopart) prosthesis than with the below-ankle concept. These features were recognized during the clinical analysis of all footwear, but there was an extra irregularity of weight progression noted with the fixed ankle of the Chopart prosthesis. The questionnaire reported stump problems to be the principal difficulty, and the follow-up revealed persistent attempts at surgical management including consideration of amputation at a higher level. It was concluded that the patient and the surgeons are likely to choose preservation of limb length over considerations of function during acute care and that the prosthetic concept best suited to deal with the resulting stump should emphasize unloading the distal part of the stump and smoothing out the impulsive force peak on the stump in late stance to minimize pain and to enhance ambulation capacity.

  16. [The novel quantitative measures of gait and posture in Parkinson's disease: cross-sectional analysis].

    PubMed

    Mano, Tomoo; Nishi, Ryoji; Kobayashi, Yosuke; Matsuo, Koji; Kobayashi, Yasushi; Kakehi, Akio

    2015-01-01

    Posture abnormality and gait impairments characterize of Parkinson's disease (PD), predict the risk of falling, and are important contributors to reduced quality of life. The quantitative measures of posture and gait may eventually provide usefulness as a biomarker in PD. This study included that 40 patients with PD (male 26, female 14, average age 70.4 ± 7.6 years old) and 17 normal healthy controls. We selected the quantified measures of the gait function, such as MDS-UPDRS, Timed up & go test, 5 feet walk test, 6 minutes-walk test. The posture angle of both forward flexion and lateral flexion were measured using the application of smartphone, which is capable even in a consulting room. The new posture quantitative measurement is stabile between examiners. The gait functions and the posture angles were significantly abnormal in the PD patients, compared to healthy controls (P < 0.001). The forward flexion angles were well correlated with the ages, on the other hand the lateral flexion angles were well correlated with the duration of the disease. The posture angles do not positively correlate with freezing gait but do correlate in limited univariate analyses with measures of gait function.

  17. Gait modification strategies in trunk over right stance phase in patients with right anterior cruciate ligament deficiency.

    PubMed

    Shi, Dongliang; Li, Nannan; Wang, Yubin; Jiang, Shuyun; Lin, Jianping; Zhu, Wenhui

    2016-05-01

    This study aimed to investigate the gait modification strategies of trunk over right stance phase in patients with right anterior cruciate ligament deficiency (ACL-D). Thirty-six patients with right chronic ACL-D were recruited, as well as 36 controls. A 3D optical video motion capture system was used during gait and stair ambulation. Kinematic variables of the trunk and kinematic and kinetic variables of the knee were calculated. Patients with chronic right ACL-D exhibited many significant abnormalities compared with controls. Trunk rotation with right shoulder trailing over the right stance phase was lower in all five motion patterns (P<0.05). Compared with controls, trunk posterior lean was higher from descending stairs to walking when the knee sagittal plane moment ended (P<0.01). Trunk lateral flexion to the left was higher when ascending stairs at the start of right knee coronal plane moment (P=0.01), when descending stairs at the maximal knee coronal plane moment (P<0.01), and when descending stairs at the end of the knee coronal plane moment (P=0.03). Trunk rotation with right shoulder forward was higher at the minimal knee transverse plane moment (P<0.01) and when the knee transverse plane moment ended (P<0.01); during walking, trunk rotation with right shoulder trailing was lower at other knee moments during other walking patterns (all P<0.01). In conclusion, gait modification strategies of the trunk were apparent in patients with ACL-D. These results provide new insights about diagnosis and rehabilitation of chronic ACL-D (better use of walking and stair tasks as part of a rehabilitation program).

  18. Emotion recognition using Kinect motion capture data of human gaits

    PubMed Central

    Li, Shun; Cui, Liqing; Zhu, Changye; Li, Baobin

    2016-01-01

    Automatic emotion recognition is of great value in many applications, however, to fully display the application value of emotion recognition, more portable, non-intrusive, inexpensive technologies need to be developed. Human gaits could reflect the walker’s emotional state, and could be an information source for emotion recognition. This paper proposed a novel method to recognize emotional state through human gaits by using Microsoft Kinect, a low-cost, portable, camera-based sensor. Fifty-nine participants’ gaits under neutral state, induced anger and induced happiness were recorded by two Kinect cameras, and the original data were processed through joint selection, coordinate system transformation, sliding window gauss filtering, differential operation, and data segmentation. Features of gait patterns were extracted from 3-dimentional coordinates of 14 main body joints by Fourier transformation and Principal Component Analysis (PCA). The classifiers NaiveBayes, RandomForests, LibSVM and SMO (Sequential Minimal Optimization) were trained and evaluated, and the accuracy of recognizing anger and happiness from neutral state achieved 80.5% and 75.4%. Although the results of distinguishing angry and happiness states were not ideal in current study, it showed the feasibility of automatically recognizing emotional states from gaits, with the characteristics meeting the application requirements. PMID:27672492

  19. Muscle Activation during Gait in Children with Duchenne Muscular Dystrophy

    PubMed Central

    Vuillerot, Carole; Tiffreau, Vincent; Peudenier, Sylviane; Cuisset, Jean-Marie; Pereon, Yann; Leboeuf, Fabien; Delporte, Ludovic; Delpierre, Yannick; Gross, Raphaël

    2016-01-01

    The aim of this prospective study was to investigate changes in muscle activity during gait in children with Duchenne muscular Dystrophy (DMD). Dynamic surface electromyography recordings (EMGs) of 16 children with DMD and pathological gait were compared with those of 15 control children. The activity of the rectus femoris (RF), vastus lateralis (VL), medial hamstrings (HS), tibialis anterior (TA) and gastrocnemius soleus (GAS) muscles was recorded and analysed quantitatively and qualitatively. The overall muscle activity in the children with DMD was significantly different from that of the control group. Percentage activation amplitudes of RF, HS and TA were greater throughout the gait cycle in the children with DMD and the timing of GAS activity differed from the control children. Significantly greater muscle coactivation was found in the children with DMD. There were no significant differences between sides. Since the motor command is normal in DMD, the hyper-activity and co-contractions likely compensate for gait instability and muscle weakness, however may have negative consequences on the muscles and may increase the energy cost of gait. Simple rehabilitative strategies such as targeted physical therapies may improve stability and thus the pattern of muscle activity. PMID:27622734

  20. Secure and privacy enhanced gait authentication on smart phone.

    PubMed

    Hoang, Thang; Choi, Deokjai

    2014-01-01

    Smart environments established by the development of mobile technology have brought vast benefits to human being. However, authentication mechanisms on portable smart devices, particularly conventional biometric based approaches, still remain security and privacy concerns. These traditional systems are mostly based on pattern recognition and machine learning algorithms, wherein original biometric templates or extracted features are stored under unconcealed form for performing matching with a new biometric sample in the authentication phase. In this paper, we propose a novel gait based authentication using biometric cryptosystem to enhance the system security and user privacy on the smart phone. Extracted gait features are merely used to biometrically encrypt a cryptographic key which is acted as the authentication factor. Gait signals are acquired by using an inertial sensor named accelerometer in the mobile device and error correcting codes are adopted to deal with the natural variation of gait measurements. We evaluate our proposed system on a dataset consisting of gait samples of 34 volunteers. We achieved the lowest false acceptance rate (FAR) and false rejection rate (FRR) of 3.92% and 11.76%, respectively, in terms of key length of 50 bits. PMID:24955403

  1. Secure and Privacy Enhanced Gait Authentication on Smart Phone

    PubMed Central

    Choi, Deokjai

    2014-01-01

    Smart environments established by the development of mobile technology have brought vast benefits to human being. However, authentication mechanisms on portable smart devices, particularly conventional biometric based approaches, still remain security and privacy concerns. These traditional systems are mostly based on pattern recognition and machine learning algorithms, wherein original biometric templates or extracted features are stored under unconcealed form for performing matching with a new biometric sample in the authentication phase. In this paper, we propose a novel gait based authentication using biometric cryptosystem to enhance the system security and user privacy on the smart phone. Extracted gait features are merely used to biometrically encrypt a cryptographic key which is acted as the authentication factor. Gait signals are acquired by using an inertial sensor named accelerometer in the mobile device and error correcting codes are adopted to deal with the natural variation of gait measurements. We evaluate our proposed system on a dataset consisting of gait samples of 34 volunteers. We achieved the lowest false acceptance rate (FAR) and false rejection rate (FRR) of 3.92% and 11.76%, respectively, in terms of key length of 50 bits. PMID:24955403

  2. Muscle Activation during Gait in Children with Duchenne Muscular Dystrophy.

    PubMed

    Ropars, Juliette; Lempereur, Mathieu; Vuillerot, Carole; Tiffreau, Vincent; Peudenier, Sylviane; Cuisset, Jean-Marie; Pereon, Yann; Leboeuf, Fabien; Delporte, Ludovic; Delpierre, Yannick; Gross, Raphaël; Brochard, Sylvain

    2016-01-01

    The aim of this prospective study was to investigate changes in muscle activity during gait in children with Duchenne muscular Dystrophy (DMD). Dynamic surface electromyography recordings (EMGs) of 16 children with DMD and pathological gait were compared with those of 15 control children. The activity of the rectus femoris (RF), vastus lateralis (VL), medial hamstrings (HS), tibialis anterior (TA) and gastrocnemius soleus (GAS) muscles was recorded and analysed quantitatively and qualitatively. The overall muscle activity in the children with DMD was significantly different from that of the control group. Percentage activation amplitudes of RF, HS and TA were greater throughout the gait cycle in the children with DMD and the timing of GAS activity differed from the control children. Significantly greater muscle coactivation was found in the children with DMD. There were no significant differences between sides. Since the motor command is normal in DMD, the hyper-activity and co-contractions likely compensate for gait instability and muscle weakness, however may have negative consequences on the muscles and may increase the energy cost of gait. Simple rehabilitative strategies such as targeted physical therapies may improve stability and thus the pattern of muscle activity. PMID:27622734

  3. Secure and privacy enhanced gait authentication on smart phone.

    PubMed

    Hoang, Thang; Choi, Deokjai

    2014-01-01

    Smart environments established by the development of mobile technology have brought vast benefits to human being. However, authentication mechanisms on portable smart devices, particularly conventional biometric based approaches, still remain security and privacy concerns. These traditional systems are mostly based on pattern recognition and machine learning algorithms, wherein original biometric templates or extracted features are stored under unconcealed form for performing matching with a new biometric sample in the authentication phase. In this paper, we propose a novel gait based authentication using biometric cryptosystem to enhance the system security and user privacy on the smart phone. Extracted gait features are merely used to biometrically encrypt a cryptographic key which is acted as the authentication factor. Gait signals are acquired by using an inertial sensor named accelerometer in the mobile device and error correcting codes are adopted to deal with the natural variation of gait measurements. We evaluate our proposed system on a dataset consisting of gait samples of 34 volunteers. We achieved the lowest false acceptance rate (FAR) and false rejection rate (FRR) of 3.92% and 11.76%, respectively, in terms of key length of 50 bits.

  4. [Development of a robotic walking simulator for gait rehabilitation].

    PubMed

    Schmidt, H; Sorowka, D; Hesse, S; Bernhardt, R

    2003-10-01

    Restoration of gait is a major concern of rehabilitation after stroke or spinal cord injury. Modern concepts of motor learning favour a task-specific repetitive approach, i.e. "whoever wants to learn to walk again must walk." However, the physical demands this places on the therapist, is a limiting factor in the clinical routine setting. This article describes a robotic walking simulator for gait training that enables wheelchair-bound subjects to freely carry out repetitive practicing of an individually adapted gait pattern under simulation of the manual guidance of an experienced therapist. The technical principle applied makes use of programmable footplates with permanent foot/machine contact in combination with compliance control. The solution chosen comprises a planar parallel-serial hybrid kinematic system with three degrees of freedom that moves the feet in the sagittal plane. Gait analysis while floor walking and stair climbing, clinical practicability and safety aspects were the basis for the design. A variable compliance control enables man-machine interaction, ranging from purely position controlled movement to full compliance during swing phase above a virtual ground profile. In full compliance mode the robotic walking simulator behaves like a haptic device. The concept presented offers new prospects for individualized gait rehabilitation.

  5. Emotion recognition using Kinect motion capture data of human gaits

    PubMed Central

    Li, Shun; Cui, Liqing; Zhu, Changye; Li, Baobin

    2016-01-01

    Automatic emotion recognition is of great value in many applications, however, to fully display the application value of emotion recognition, more portable, non-intrusive, inexpensive technologies need to be developed. Human gaits could reflect the walker’s emotional state, and could be an information source for emotion recognition. This paper proposed a novel method to recognize emotional state through human gaits by using Microsoft Kinect, a low-cost, portable, camera-based sensor. Fifty-nine participants’ gaits under neutral state, induced anger and induced happiness were recorded by two Kinect cameras, and the original data were processed through joint selection, coordinate system transformation, sliding window gauss filtering, differential operation, and data segmentation. Features of gait patterns were extracted from 3-dimentional coordinates of 14 main body joints by Fourier transformation and Principal Component Analysis (PCA). The classifiers NaiveBayes, RandomForests, LibSVM and SMO (Sequential Minimal Optimization) were trained and evaluated, and the accuracy of recognizing anger and happiness from neutral state achieved 80.5% and 75.4%. Although the results of distinguishing angry and happiness states were not ideal in current study, it showed the feasibility of automatically recognizing emotional states from gaits, with the characteristics meeting the application requirements.

  6. Accurate and Reliable Gait Cycle Detection in Parkinson's Disease.

    PubMed

    Hundza, Sandra R; Hook, William R; Harris, Christopher R; Mahajan, Sunny V; Leslie, Paul A; Spani, Carl A; Spalteholz, Leonhard G; Birch, Benjamin J; Commandeur, Drew T; Livingston, Nigel J

    2014-01-01

    There is a growing interest in the use of Inertial Measurement Unit (IMU)-based systems that employ gyroscopes for gait analysis. We describe an improved IMU-based gait analysis processing method that uses gyroscope angular rate reversal to identify the start of each gait cycle during walking. In validation tests with six subjects with Parkinson disease (PD), including those with severe shuffling gait patterns, and seven controls, the probability of True-Positive event detection and False-Positive event detection was 100% and 0%, respectively. Stride time validation tests using high-speed cameras yielded a standard deviation of 6.6 ms for controls and 11.8 ms for those with PD. These data demonstrate that the use of our angular rate reversal algorithm leads to improvements over previous gyroscope-based gait analysis systems. Highly accurate and reliable stride time measurements enabled us to detect subtle changes in stride time variability following a Parkinson's exercise class. We found unacceptable measurement accuracy for stride length when using the Aminian et al gyro-based biomechanical algorithm, with errors as high as 30% in PD subjects. An alternative method, using synchronized infrared timing gates to measure velocity, combined with accurate mean stride time from our angular rate reversal algorithm, more accurately calculates mean stride length.

  7. Emotion recognition using Kinect motion capture data of human gaits.

    PubMed

    Li, Shun; Cui, Liqing; Zhu, Changye; Li, Baobin; Zhao, Nan; Zhu, Tingshao

    2016-01-01

    Automatic emotion recognition is of great value in many applications, however, to fully display the application value of emotion recognition, more portable, non-intrusive, inexpensive technologies need to be developed. Human gaits could reflect the walker's emotional state, and could be an information source for emotion recognition. This paper proposed a novel method to recognize emotional state through human gaits by using Microsoft Kinect, a low-cost, portable, camera-based sensor. Fifty-nine participants' gaits under neutral state, induced anger and induced happiness were recorded by two Kinect cameras, and the original data were processed through joint selection, coordinate system transformation, sliding window gauss filtering, differential operation, and data segmentation. Features of gait patterns were extracted from 3-dimentional coordinates of 14 main body joints by Fourier transformation and Principal Component Analysis (PCA). The classifiers NaiveBayes, RandomForests, LibSVM and SMO (Sequential Minimal Optimization) were trained and evaluated, and the accuracy of recognizing anger and happiness from neutral state achieved 80.5% and 75.4%. Although the results of distinguishing angry and happiness states were not ideal in current study, it showed the feasibility of automatically recognizing emotional states from gaits, with the characteristics meeting the application requirements. PMID:27672492

  8. Gait phase varies over velocities.

    PubMed

    Liu, Yancheng; Lu, Kun; Yan, Songhua; Sun, Ming; Lester, D Kevin; Zhang, Kuan

    2014-02-01

    We sought to characterize the percent (PT) of the phases of a gait cycle (GC) as velocity changes to establish norms for pathological gait characteristics with higher resolution technology. Ninety five healthy subjects (49 males and 46 females with age 34.9 ± 11.8 yrs, body weight 64.0 ± 11.7 kg and BMI 23.5 ± 3.6) were enrolled and walked comfortably on a 10-m walkway at self-selected slower, normal, and faster velocities. Walking was recorded with a high speed camera (250 frames per second) and the eight phases of a GC were determined by examination of individual frames for each subject. The correlation coefficients between the mean PT of the phases of the three velocities gaits and PT defined by previous publications were all greater than 0.99. The correlation coefficient between velocity and PT of gait phases is -0.83 for loading response (LR), -0.75 for mid stance (MSt), and -0.84 for pre-swing (PSw). While the PT of the phases of three velocities from this study are highly correlated with PT described by Dr. Jacquenlin Perry decades ago, actual PT of each phase varied amongst these individuals with the largest coefficient variation of 24.31% for IC with slower velocity. From slower to faster walk, the mean PT of MSt diminished from 35.30% to 25.33%. High resolution recording revealed ambiguity of some gait phase definitions, and these data may benefit GC characterization of normal and pathological gait in clinical practice. The study results indicate that one should consider individual variations and walking velocity when evaluating gaits of subjects using standard gait phase classification.

  9. [Clinical gait analysis: user guide].

    PubMed

    Armand, Stéphane; Bonnefoy-Mazure, Alice; Hoffmeyer, Pierre; De Coulon, Geraldo

    2015-10-14

    Clinical gait analysis has become an indispensable medical examination for the management of patients with complex gait disorders. As its name suggests, the purpose of this examination is to assess patients whilst they are walking in a laboratory setting. Measurements include: 3 dimensional joint motion, forces applied to joints, and electromyographic muscle activity. This quantitative data allows identification of walking deviations and to deduce the likely causes of these deviations thanks to the clinical data available for each patient.

  10. Influence of velocity on variability in gait kinematics: implications for recognition in forensic science.

    PubMed

    Yang, Sylvia X M; Larsen, Peter K; Alkjaer, Tine; Lynnerup, Niels; Simonsen, Erik B

    2014-09-01

    Closed circuit television (CCTV) footage is often available from crime scenes and may be used to compare perpetrators with suspects. Usually, the footage comprises incomplete gait cycles at different velocities, making gait pattern identification from crimes difficult. This study investigated the concurrence of joint angles throughout a gait cycle at three different velocities (3.0, 4.5, 6.0 km/h). Six datasets at each velocity were collected from 16 men. A variability range VR throughout the gait cycle at each velocity for each joint angle for each person was calculated. The joint angles at each velocity were compared pairwise, and whenever this showed values within the VR of this velocity, the case was positive. By adding the positives throughout the gait cycle, phases with high and low concurrences were located; peak concurrence was observed at mid-stance phase. Striving for the same velocity for the suspect and perpetrator is recommended.

  11. 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.

  12. A wireless sensory feedback system for real-time gait modification.

    PubMed

    Redd, Christian B; Bamberg, Stacy J Morris

    2011-01-01

    Current rehabilitation technology and techniques have proven effective at modifying and correcting gait abnormalities. They are however limited to laboratory and clinical settings, under the supervision of a specialist. Conventional techniques for quantifying gait asymmetries can be combined with sensory feedback methods to provide an intuitive and inexpensive feedback system for extra-clinical rehabilitation. A wireless feedback system has been designed to collect gait information, process it in real-time, and provide corrective feedback to the user. The corrective feedback can be presented through visual, audible, or vibrotactile methods, or a combination thereof. Initial results have led to improvement in the sensory interface of the device to maximize the corrective influence on inexperienced subjects. These preliminary findings suggest that the wireless feedback device can influence the gait of the user, and effectively adapt to their personal feedback preferences.

  13. Haem degradation in abnormal haemoglobins.

    PubMed Central

    Brown, S B; Docherty, J C

    1978-01-01

    The coupled oxidation of certain abnormal haemoglobins leads to different bile-pigment isomer distributions from that of normal haemoglobin. The isomer pattern may be correlated with the structure of the abnormal haemoglobin in the neighbourhood of the haem pocket. This is support for haem degradation by an intramolecular reaction. PMID:708385

  14. Gait and balance analysis for patients with Alzheimer's disease using an inertial-sensor-based wearable instrument.

    PubMed

    Hsu, Yu-Liang; Chung, Pau-Choo Julia; Wang, Wei-Hsin; Pai, Ming-Chyi; Wang, Chun-Yao; Lin, Chien-Wen; Wu, Hao-Li; Wang, Jeen-Shing

    2014-11-01

    Despite patients with Alzheimer's disease (AD) were reported of revealing gait disorders and balance problems, there is still lack of objective quantitative measurement of gait patterns and balance capability of AD patients. Based on an inertial-sensor-based wearable device, this paper develops gait and balance analyzing algorithms to obtain quantitative measurements and explores the essential indicators from the measurements for AD diagnosis. The gait analyzing algorithm is composed of stride detection followed by gait cycle decomposition so that gait parameters are developed from the decomposed gait details. On the other hand, the balance is measured by the sway speed in anterior-posterior (AP) and medial-lateral (ML) directions of the projection path of body's center of mass (COM). These devised gait and balance parameters were explored on twenty-one AD patients and fifty healthy controls (HCs). Special evaluation procedure including single-task and dual-task walking experiments for observing the cognitive function and attention is also devised for the comparison of AD and HC groups. Experimental results show that the wearable instrument with the designed gait and balance analyzing system is a promising tool for automatically analyzing gait information and balance ability, serving as assistant indicators for early diagnosis of AD.

  15. 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.

  16. Coupled oscillators utilised as gait rhythm generators of a two-legged walking machine.

    PubMed

    Zielińska, T

    1996-03-01

    The gait of current two-legged walking machines differs from that of humans, although the kinematic structures of these machines' legs frequently imitate human limbs. This paper presents a method of generating the trajectories of hip and knee joint angles resulting in a gait pattern similar to that of a human. For this purpose the solutions of coupled van der Pol oscillator equations are utilised. There is much evidence that these equations can be treated as a good model of the central pattern generator generating functional (also locomotional) rhythms in living creatures. The oscillator equations are solved by numerical integration. The method of changing the type of gait by changing appropriate parameter values in the oscillator equations is presented (change of velocity and trajectory of leg-ends). The results obtained enable enhanced control of two-legged walking systems by including gait pattern generators which will assume a similar role to that of biological generators.

  17. Swing-through gait with free-knees produced by surface functional electrical stimulation.

    PubMed

    Heller, B W; Granat, M H; Andrews, B J

    1996-01-01

    The swing-through gait is often the gait of choice for those crutch walkers who can perform it. However, a practical (sufficiently low energy and sufficiently fast) gait is usually not achievable by paraplegic individuals with thoracic lesions. Functional electrical stimulation (FES) was used to assist three spinal cord injured (SCI) subjects with complete thoracic lesions at T11, T11 and T6 to ambulate with a swing-through gait patten. Eight channels of surface stimulation were used to bilaterally stimulate knee extensors, knee flexors, hip extensors and hip flexors. The stimulation sequence was controlled by a computer that implemented a finite-state, rule-based control strategy according to sensor inputs. Over a long, level walkway, the T11 subjects averaged 0.40 m/s and 0.38 m/s for distances of 56 m and 51 m; the T6 subject averaged 0.30 m/s for 43 m. Using a motion analysis system, the gait patterns of two of the subjects were compared to those of a trained, non-impaired subject. The SCI subjects spent more time in both double support phases (when both crutches and both feet contact the floor) than did the non-impaired subjects, leading to a loss of momentum and hence a slower and less efficient gait. In conclusion, an FES assisted swing-through gait is shown to be a potentially useful mode of FES gait.

  18. Prevalence and pattern of abnormal myocardial perfusion in patients with isolated coronary artery ectasia: study by 99mTc-sestamibi radionuclide scintigraphy.

    PubMed

    Ismail, Ahmed M; Rayan, Mona; Adel, Amr; Demerdash, Salah; Atef, Mohamed; Abdallah, Mohamed; Nammas, Wail

    2014-02-01

    We explored the prevalence and pattern of abnormal myocardial perfusion in patients with isolated coronary artery ectasia (CAE), as demonstrated by (99m)Tc-sestamibi scintigraphy. Prospectively, we enrolled 35 patients with angiographically documented CAE and no significant coronary obstruction, who underwent elective coronary angiography. Patients underwent Stress-rest (99m)Tc-sestamibi scintigraphy within 4 days of coronary angiography. They were divided into 2 groups: group I: with normal perfusion scan; and group II: with reversible perfusion defects. The mean age was 49.6 ± 6.9 years; 34 (97.1 %) were males. Seventy-nine (75.2 %) arteries were affected by CAE. Among 79 arteries affected by CAE, affection was diffuse in 37 (46.8 %). Thirteen (37.1 %) patients had normal perfusion scan (group I), whereas 22 (62.9 %) had reversible perfusion defects (group II). Among 22 patients with reversible perfusion defects, 20 (90.9 %) had mild and 2 (9.1 %) had moderate ischemia. Among 49 myocardial segments with reversible perfusion defects, 22 (44.9 %) were basal, 18 (36.7 %) mid-, and 9 (18.4 %) apical segments. Diffuse CAE was significantly more prevalent in group II versus group I, in all 3 major coronary arteries (p < 0.05 for all). In patients with isolated CAE who underwent elective coronary angiography, reversible perfusion defects demonstrated by (99m)Tc-sestamibi scintigraphy were rather prevalent, mostly mild, more likely to affect the basal and mid-segments of the myocardium, and more frequently associated with diffuse ectasia.

  19. The division abnormally delayed (dally) gene: a putative integral membrane proteoglycan required for cell division patterning during postembryonic development of the nervous system in Drosophila.

    PubMed

    Nakato, H; Futch, T A; Selleck, S B

    1995-11-01

    We have devised a genetic screen to obtain mutants affecting cell division patterning in the developing central nervous system of Drosophila. The division abnormally delayed (dally) locus was identified using a combination of "enhancer trap" and behavioral screening methods. The ordered cell cycle progression of lamina precursor cells, which generate synaptic target neurons for photoreceptors, is disrupted in dally mutants. The first of two lamina precursor cell divisions shows a delayed entry into mitosis. The second division, one that is triggered by an intercellular signal from photoreceptor axons, fails to take place. Similar to lamina precursors, cells that generate the ommatidia of the adult eye show two synchronized divisions found along the morphogenetic furrow in the eye disc and the first division cycle in dally mutants displays a delayed progression into M phase like that found in the first lamina precursor cell division. dally mutations also affect viability and produce morphological defects in several adult tissues, including the eye, antenna, wing and genitalia. Sequencing of a dally cDNA reveals a potential open reading frame of 626 amino acids with homology to a family of Glypican-related integral membrane proteoglycans. These heparan sulfate-containing proteins are attached to the external leaflet of the plasma membrane via a glycosylphosphatidylinositol linkage. Heparan sulfate proteoglycans may serve as co-receptors for a variety of secreted proteins including fibroblast growth factor, vascular endothelial growth factor, hepatocyte growth factor and members of the Wnt, TGF-beta and Hedgehog families. The cell division defects found in dally mutants implicate the Glypican group of integral membrane proteoglycans in the control of cell division during development.

  20. Multi-complexity ensemble measures for gait time series analysis: application to diagnostics, monitoring and biometrics.

    PubMed

    Gavrishchaka, Valeriy; Senyukova, Olga; Davis, Kristina

    2015-01-01

    Previously, we have proposed to use complementary complexity measures discovered by boosting-like ensemble learning for the enhancement of quantitative indicators dealing with necessarily short physiological time series. We have confirmed robustness of such multi-complexity measures for heart rate variability analysis with the emphasis on detection of emerging and intermittent cardiac abnormalities. Recently, we presented preliminary results suggesting that such ensemble-based approach could be also effective in discovering universal meta-indicators for early detection and convenient monitoring of neurological abnormalities using gait time series. Here, we argue and demonstrate that these multi-complexity ensemble measures for gait time series analysis could have significantly wider application scope ranging from diagnostics and early detection of physiological regime change to gait-based biometrics applications.

  1. Alterations of functional and structural connectivity of freezing of gait in Parkinson's disease.

    PubMed

    Wang, Min; Jiang, Siming; Yuan, Yongsheng; Zhang, Li; Ding, Jian; Wang, Jianwei; Zhang, Jiejin; Zhang, Kezhong; Wang, Jie

    2016-08-01

    This study assessed the patterns of functional and structural connectivity abnormalities in patients with Parkinson's disease with freezing of gait (PD FOG+) compared with those without freezing (PD FOG-) and healthy controls (HCs). Resting state functional MRI (rs-fMRI) and diffusion tensor imaging (DTI) scans were obtained from 14 PD FOG+, 16 PD FOG- and 16HCs. Between-group difference in pedunculopontine nucleus (PPN) functional connectivity (FC) was performed to assess FC dysfunction. Tract-based spatial statistics (TBSS) was applied to compare white matter (WM) impairment across the whole brain between groups. PD FOG+ patients exhibited abnormal PPN FC, compared with HCs and with PD FOG-, mainly in the corticopontine-cerebellar pathways (in the bilateral cerebellum and in the pons), as well as the visual temporal areas (in the right middle temporal gyrus and in the right inferior temporal gyrus). Moreover, PD FOG+ patients, showed more pronounced WM abnormalities, relative to controls, including the interhemispheric connections of corpus callosum, the cortico-cortical WM tracts of the cingulum, the superior longitudinal fasciculus and inferior fronto-occipital fasciculus, the corticofugal tract (cerebral peduncles, internal capsule, corona radiata), as well as tracts connecting the thalamus (thalamic radiation). This study suggests that FOG in PD is associated with abnormal PPN FC network, mainly affecting the corticopontine-cerebellar pathways as well as visual temporal areas involved in visual processing, and with diffuse WM deficits extending to motor, sensory and cognitive regions. Combining rs-fMRI and DTI method, our study should advance the understanding of neural mechanisms underlying FOG in PD. PMID:27230857

  2. Simulation of normal and pathological gaits using a fusion knowledge strategy

    PubMed Central

    2013-01-01

    Gait distortion is the first clinical manifestation of many pathological disorders. Traditionally, the gait laboratory has been the only available tool for supporting both diagnosis and prognosis, but under the limitation that any clinical interpretation depends completely on the physician expertise. This work presents a novel human gait model which fusions two important gait information sources: an estimated Center of Gravity (CoG) trajectory and learned heel paths, by that means allowing to reproduce kinematic normal and pathological patterns. The CoG trajectory is approximated with a physical compass pendulum representation that has been extended by introducing energy accumulator elements between the pendulum ends, thereby emulating the role of the leg joints and obtaining a complete global gait description. Likewise, learned heel paths captured from actual data are learned to improve the performance of the physical model, while the most relevant joint trajectories are estimated using a classical inverse kinematic rule. The model is compared with standard gait patterns, obtaining a correlation coefficient of 0.96. Additionally,themodel simulates neuromuscular diseases like Parkinson (phase 2, 3 and 4) and clinical signs like the Crouch gait, case in which the averaged correlation coefficient is 0.92. PMID:23844901

  3. Gait analysis in hip viscosupplementation for osteoarthritis: a case report.

    PubMed

    Di Lorenzo, L

    2013-10-31

    Hip is a site very commonly affected by osteoarthritis and the intra-articular administration of hyaluronic acid in the management of osteoarthritic pain is increasingly used. However, the debate about its usefulness is still ongoing, as not all results of clinical trials confirm its effectiveness. In order to achieve the best outcome, clinical assessment and treatment choices should be based on subjective outcome, pathological and mechanical findings that should be integrated with qualitative analysis of human movement. After viscosupplementation, clinical trials often evaluate as endpoint subjective outcomes (i.e. pain visual analogic scale) and static imaging such as radiographs and magnetic resonance imaging. In our clinical practice we use gait analysis as part of rehabilitation protocol to measure performance, enhancement and changes of several biomechanical factors. Taking advantage of available resources (BTS Bioengineering gait analysis Elite System) we studied a patient's gait after ultrasound guided hip injections for viscosupplementation. He showed an early clinical and biomechanical improvement during walking after a single intra articular injection of hyaluronic acid. Gait analysis parameters obtained suggest that the pre-treatment slower speed may be caused by antalgic walking patterns, the need for pain control and muscle weakness. After hip viscosupplementation, the joint displayed different temporal, kinetic and kinematic parameters associated with improved pain patterns.

  4. Use of gait parameters of persons in video surveillance systems

    NASA Astrophysics Data System (ADS)

    Geradts, Zeno J.; Merlijn, Menno; de Groot, Gert; Bijhold, Jurrien

    2002-07-01

    The gait parameters of eleven subjects were evaluated to provide data for recognition purposes of subjects. Video images of these subjects were acquired in frontal, transversal, and sagittal (a plane parallel to the median of the body) view. The subjects walked by at their usual walking speed. The measured parameters were hip, knee and ankle joint angle and their time averaged values, thigh, foot and trunk angle, step length and width, cycle time and walking speed. Correlation coefficients within and between subjects for the hip, knee and ankle rotation pattern in the sagittal aspect and for the trunk rotation pattern in the transversal aspect were almost similar. (were similar or were almost identical) This implies that the intra and inter individual variance were equal. Therefore, these gait parameters could not distinguish between subjects. A simple ANOVA with a follow-up test was used to detect significant differences for the mean hip, knee and ankle joint angle, thigh angle, step length, step width, walking speed, cycle time and foot angle. The number of significant differences between subjects defined the usefulness of the gait parameter. The parameter with the most significant difference between subjects was the foot angle (64 % - 73 % of the maximal attainable significant differences), followed by the time average hip joint angle (58 %) and the step length (45 %). The other parameters scored less than 25 %, which is poor for recognition purposes. The use of gait for identification purposes it not yet possible based on this research.

  5. A Global Gait Asymmetry Index.

    PubMed

    Cabral, Silvia; Resende, Renan A; Clansey, Adam C; Deluzio, Kevin J; Selbie, W Scott; Veloso, António P

    2016-04-01

    High levels of gait asymmetry are associated with many pathologies. Our long-term goal is to improve gait symmetry through real-time biofeedback of a symmetry index. Symmetry is often reported as a single metric or a collective signature of multiple discrete measures. While this is useful for assessment, incorporating multiple feedback metrics presents too much information for most subjects to use as visual feedback for gait retraining. The aim of this article was to develop a global gait asymmetry (GGA) score that could be used as a biofeedback metric for gait retraining and to test the effectiveness of the GGA for classifying artificially-induced asymmetry. Eighteen participants (11 males; age 26.9 y [SD = 7.7]; height 1.8 m [SD = 0.1]; body mass 72.7 kg [SD = 8.9]) walked on a treadmill in 3 symmetry conditions, induced by wearing custom-made sandals: a symmetric condition (identical sandals) and 2 asymmetric conditions (different sandals). The GGA score was calculated, based on several joint angles, and compared between conditions. Significant differences were found among all conditions (P < .001), meaning that the GGA score is sensitive to different levels of asymmetry, and may be useful for rehabilitation and assessment.

  6. A Global Gait Asymmetry Index.

    PubMed

    Cabral, Silvia; Resende, Renan A; Clansey, Adam C; Deluzio, Kevin J; Selbie, W Scott; Veloso, António P

    2016-04-01

    High levels of gait asymmetry are associated with many pathologies. Our long-term goal is to improve gait symmetry through real-time biofeedback of a symmetry index. Symmetry is often reported as a single metric or a collective signature of multiple discrete measures. While this is useful for assessment, incorporating multiple feedback metrics presents too much information for most subjects to use as visual feedback for gait retraining. The aim of this article was to develop a global gait asymmetry (GGA) score that could be used as a biofeedback metric for gait retraining and to test the effectiveness of the GGA for classifying artificially-induced asymmetry. Eighteen participants (11 males; age 26.9 y [SD = 7.7]; height 1.8 m [SD = 0.1]; body mass 72.7 kg [SD = 8.9]) walked on a treadmill in 3 symmetry conditions, induced by wearing custom-made sandals: a symmetric condition (identical sandals) and 2 asymmetric conditions (different sandals). The GGA score was calculated, based on several joint angles, and compared between conditions. Significant differences were found among all conditions (P < .001), meaning that the GGA score is sensitive to different levels of asymmetry, and may be useful for rehabilitation and assessment. PMID:26502455

  7. Gait post-stroke: Pathophysiology and rehabilitation strategies.

    PubMed

    Beyaert, C; Vasa, R; Frykberg, G E

    2015-11-01

    We reviewed neural control and biomechanical description of gait in both non-disabled and post-stroke subjects. In addition, we reviewed most of the gait rehabilitation strategies currently in use or in development and observed their principles in relation to recent pathophysiology of post-stroke gait. In both non-disabled and post-stroke subjects, motor control is organized on a task-oriented basis using a common set of a few muscle modules to simultaneously achieve body support, balance control, and forward progression during gait. Hemiparesis following stroke is due to disruption of descending neural pathways, usually with no direct lesion of the brainstem and cerebellar structures involved in motor automatic processes. Post-stroke, improvements of motor activities including standing and locomotion are variable but are typically characterized by a common postural behaviour which involves the unaffected side more for body support and balance control, likely in response to initial muscle weakness of the affected side. Various rehabilitation strategies are regularly used or in development, targeting muscle activity, postural and gait tasks, using more or less high-technology equipment. Reduced walking speed often improves with time and with various rehabilitation strategies, but asymmetric postural behaviour during standing and walking is often reinforced, maintained, or only transitorily decreased. This asymmetric compensatory postural behaviour appears to be robust, driven by support and balance tasks maintaining the predominant use of the unaffected side over the initially impaired affected side. Based on these elements, stroke rehabilitation including affected muscle strengthening and often stretching would first need to correct the postural asymmetric pattern by exploiting postural automatic processes in various particular motor tasks secondarily beneficial to gait.

  8. The association between intersegmental coordination in the lower limb and gait speed in elderly females.

    PubMed

    Ogaya, Shinya; Iwata, Akira; Higuchi, Yumi; Fuchioka, Satoshi

    2016-07-01

    Human multi-segmental motion is a complex task requiring motor coordination. Uncoordinated motor control may contribute to the decline in mobility; however, it is unknown whether the age-related decline in intersegmental coordination relates to the decline in gait performance. The aim of this study was to clarify the association between intersegmental coordination and gait speed in elderly females. Gait measurements were performed in 91 community-dwelling elderly females over 60 years old. Foot, shank, and thigh sagittal motions were assessed. Intersegmental coordination was analyzed using the mean value of the continuous relative phase (mCRP) during four phases of the gait cycle to investigate phase differences in foot-shank and shank-thigh motions during a normal gait. The results showed that foot-shank mCRP at late stance had negative correlations with gait speed (r=-0.53) and cadence (r=-0.54) and a positive correlation with age (r=0.25). In contrast, shank-thigh mCRP at late stance had positive correlations with gait speed (r=0.37) and cadence (r=0.56). Moreover, partial correlation, controlling age, height, and weight, revealed that foot-shank mCRP at late stance had negative correlations with gait speed (r=-0.52) and cadence (r=-0.54). Shank-thigh mCRP at late stance had a positive correlation with gait speed (r=0.28) and cadence (r=0.51). These findings imply that the foot-shank and shank-thigh coordination patterns at late stance relate to gait speed, and uncoordinated lower limb motion is believed to be associated with the age-related decline in cadence. PMID:27477700

  9. Independent Influence of Gait Speed and Step Length on Stability and Fall Risk

    PubMed Central

    Espy, D. D.; Yang, F.; Bhatt, T.; Pai, Y.-C.

    2010-01-01

    With aging, individuals' gaits become slower and their steps shorter; both are thought to improve stability against balance threats. Recent studies have shown that shorter step lengths, which bring the center of mass (COM) closer to the leading foot, improve stability against slip-related falls. However, a slower gait, hence lower COM velocity, does the opposite. Due to the inherent coupling of step length and speed in spontaneous gait, the extent to which the benefit of shorter steps can offset the slower speed is unknown. The purpose of this study was to investigate, through decoupling, the independent effects of gait speed and step length on gait stability and the likelihood of slip-induced falls. Fifty-seven young adults walked at one of three target gait patterns, two of equal speed and two of equal step length; at a later trial, they encountered an unannounced slip. The results supported our hypotheses that faster gait as well as shorter steps each ameliorates fall risk when a slip is encountered. This appeared to be attributable to the maintenance of stability from slip initiation to liftoff of the recovery foot during the slip. Successful decoupling of gait speed from step length reveals for the first time that, although slow gait in itself leads to instability and falls (a one-standard-deviation decrease in gait speed increases the odds of fall by 4 fold), this effect is offset by the related decrease in step length (the same one-standard-deviation decrease in step length lowers fall risk by 6 times). PMID:20655750

  10. The association between intersegmental coordination in the lower limb and gait speed in elderly females.

    PubMed

    Ogaya, Shinya; Iwata, Akira; Higuchi, Yumi; Fuchioka, Satoshi

    2016-07-01

    Human multi-segmental motion is a complex task requiring motor coordination. Uncoordinated motor control may contribute to the decline in mobility; however, it is unknown whether the age-related decline in intersegmental coordination relates to the decline in gait performance. The aim of this study was to clarify the association between intersegmental coordination and gait speed in elderly females. Gait measurements were performed in 91 community-dwelling elderly females over 60 years old. Foot, shank, and thigh sagittal motions were assessed. Intersegmental coordination was analyzed using the mean value of the continuous relative phase (mCRP) during four phases of the gait cycle to investigate phase differences in foot-shank and shank-thigh motions during a normal gait. The results showed that foot-shank mCRP at late stance had negative correlations with gait speed (r=-0.53) and cadence (r=-0.54) and a positive correlation with age (r=0.25). In contrast, shank-thigh mCRP at late stance had positive correlations with gait speed (r=0.37) and cadence (r=0.56). Moreover, partial correlation, controlling age, height, and weight, revealed that foot-shank mCRP at late stance had negative correlations with gait speed (r=-0.52) and cadence (r=-0.54). Shank-thigh mCRP at late stance had a positive correlation with gait speed (r=0.28) and cadence (r=0.51). These findings imply that the foot-shank and shank-thigh coordination patterns at late stance relate to gait speed, and uncoordinated lower limb motion is believed to be associated with the age-related decline in cadence.

  11. Gait energetic efficiency in older adults with and without knee pain: results from the Baltimore Longitudinal Study of Aging.

    PubMed

    Ko, Seung-Uk; Simonsick, Eleanor M; Ferrucci, Luigi

    2015-02-01

    With aging, customary gait patterns change and energetic efficiency declines, but the relationship between these alterations is not well understood. If gait characteristics that develop with aging explain part of the decline in energetic efficiency that occur in most aging individuals, then efforts to modify these characteristics could delay or prevent mobility limitation. This study characterizes gait patterns in older persons with and without knee pain and tests the hypothesis that changes in gait characteristics due to knee pain are associated with increased energetic cost of walking in older adults. Study participants were 364 men and 170 women aged 60 to 96 years enrolled in the Baltimore Longitudinal Study of Aging (BLSA), of whom 86 had prevalent knee pain. Gait patterns were assessed at participant self-selected usual pace in the gait laboratory, and the energetic cost of walking was assessed by indirect calorimetry during self-selected usual pace walking over 2.5 min in a tiled corridor using a portable equipment. Participants with knee pain were less energetically efficient than those without pain (oxygen consumption 0.97 vs. 0.88 ml/(10 m · 100 kg); p = 0.002) and had slower gait speed and smaller range of motion (ROM) at the hip and knee joints (p < 0.05, for all). Slower gait speed and lower knee ROM in participants with knee pain and longer double support time and higher ankle ROM in participants without knee pain were associated with lower energetic efficiency (p < 0.05, for all). Slower gait speed and lower knee ROM were correlates of knee pain and were found to mediate the association between age and oxygen consumption. Although knee pain is associated with a higher energetic cost of walking, gait characteristics associated with energetic efficiency differ by pain status which suggests that compensatory strategies both in the presence and absence of pain may impact gait efficiency.

  12. A mechanical energy analysis of gait initiation

    NASA Technical Reports Server (NTRS)

    Miller, C. A.; Verstraete, M. C.

    1999-01-01

    The analysis of gait initiation (the transient state between standing and walking) is an important diagnostic tool to study pathologic gait and to evaluate prosthetic devices. While past studies have quantified mechanical energy of the body during steady-state gait, to date no one has computed the mechanical energy of the body during gait initiation. In this study, gait initiation in seven normal male subjects was studied using a mechanical energy analysis to compute total body energy. The data showed three separate states: quiet standing, gait initiation, and steady-state gait. During gait initiation, the trends in the energy data for the individual segments were similar to those seen during steady-state gait (and in Winter DA, Quanbury AO, Reimer GD. Analysis of instantaneous energy of normal gait. J Biochem 1976;9:253-257), but diminished in amplitude. However, these amplitudes increased to those seen in steady-state during the gait initiation event (GIE), with the greatest increase occurring in the second step due to the push-off of the foundation leg. The baseline level of mechanical energy was due to the potential energy of the individual segments, while the cyclic nature of the data was indicative of the kinetic energy of the particular leg in swing phase during that step. The data presented showed differences in energy trends during gait initiation from those of steady state, thereby demonstrating the importance of this event in the study of locomotion.

  13. Gait Stability in Children with Cerebral Palsy

    ERIC Educational Resources Information Center

    Bruijn, Sjoerd M.; Millard, Matthew; van Gestel, Leen; Meyns, Pieter; Jonkers, Ilse; Desloovere, Kaat

    2013-01-01

    Children with unilateral Cerebral Palsy (CP) have several gait impairments, amongst which impaired gait stability may be one. We tested whether a newly developed stability measure (the foot placement estimator, FPE) which does not require long data series, can be used to asses gait stability in typically developing (TD) children as well as…

  14. Effects of Auditory Rhythm and Music on Gait Disturbances in Parkinson’s Disease

    PubMed Central

    Ashoori, Aidin; Eagleman, David M.; Jankovic, Joseph

    2015-01-01

    Gait abnormalities, such as shuffling steps, start hesitation, and freezing, are common and often incapacitating symptoms of Parkinson’s disease (PD) and other parkinsonian disorders. Pharmacological and surgical approaches have only limited efficacy in treating these gait disorders. Rhythmic auditory stimulation (RAS), such as playing marching music and dance therapy, has been shown to be a safe, inexpensive, and an effective method in improving gait in PD patients. However, RAS that adapts to patients’ movements may be more effective than rigid, fixed-tempo RAS used in most studies. In addition to auditory cueing, immersive virtual reality technologies that utilize interactive computer-generated systems through wearable devices are increasingly used for improving brain–body interaction and sensory–motor integration. Using multisensory cues, these therapies may be particularly suitable for the treatment of parkinsonian freezing and other gait disorders. In this review, we examine the affected neurological circuits underlying gait and temporal processing in PD patients and summarize the current studies demonstrating the effects of RAS on improving these gait deficits. PMID:26617566

  15. Why is walker-assisted gait metabolically expensive?

    PubMed

    Priebe, Jonathon R; Kram, Rodger

    2011-06-01

    Walker-assisted gait is reported to be ∼200% more metabolically expensive than normal bipedal walking. However, previous studies compared different walking speeds. Here, we compared the metabolic power consumption and basic stride temporal-spatial parameters for 10 young, healthy adults walking without assistance and using 2-wheeled (2W), 4-wheeled (4W) and 4-footed (4F) walker devices, all at the same speed, 0.30m/s. We also measured the metabolic power demand for walking without any assistive device using a step-to gait at 0.30m/s, walking normally at 1.25m/s, and for repeated lifting of the 4F walker mimicking the lifting pattern used during 4F walker-assisted gait. Similar to previous studies, we found that the cost per distance walked was 217% greater with a 4F walker at 0.30m/s compared to unassisted, bipedal walking at 1.25m/s. Compared at the same speed, 0.30m/s, using a 4F walker was still 82%, 74%, and 55% energetically more expensive than walking unassisted, with a 4W walker and a 2W walker respectively. The sum of the metabolic cost of step-to walking plus the cost of lifting itself was equivalent to the cost of walking with a 4F walker. Thus, we deduce that the high cost of 4F walker assisted gait is due to three factors: the slow walking speed, the step-to gait pattern and the repeated lifting of the walker.

  16. Assist-as-Needed Robot-Aided Gait Training Improves Walking Function in Individuals Following Stroke.

    PubMed

    Srivastava, Shraddha; Kao, Pei-Chun; Kim, Seok Hun; Stegall, Paul; Zanotto, Damiano; Higginson, Jill S; Agrawal, Sunil K; Scholz, John P

    2015-11-01

    A novel robot-aided assist-as-needed gait training paradigm has been developed recently. This paradigm encourages subjects' active participation during training. Previous pilot studies demonstrated that assist-as-needed robot-aided gait training (RAGT) improves treadmill walking performance post-stroke. However, it is not known if there is an over-ground transfer of the training effects from RAGT on treadmill or long-term retention of the effects. The purpose of the current study was to examine the effects of assist-as-needed RAGT on over-ground walking pattern post-stroke. Nine stroke subjects received RAGT with visual feedback of each subject's instantaneous ankle malleolus position relative to a target template for 15 40-minute sessions. Clinical evaluations and gait analyses were performed before, immediately after, and 6 months post-training. Stroke subjects demonstrated significant improvements and some long-term retention of the improvements in their self-selected over-ground walking speed, Dynamic Gait Index, Timed Up and Go, peak knee flexion angle during swing phase and total hip joint excursion over the whole gait cycle for their affected leg . These preliminary results demonstrate that subjects improved their over-ground walking pattern and some clinical gait measures post-training suggesting that assist-as-needed RAGT including visual feedback may be an effective approach to improve over-ground walking pattern post-stroke.

  17. Neuromuscular adjustments of gait associated with unstable conditions.

    PubMed

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

    2015-11-01

    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

  18. Gait characterization for osteoarthritis patients using wearable gait sensors (H-Gait systems).

    PubMed

    Tadano, Shigeru; Takeda, Ryo; Sasaki, Keita; Fujisawa, Tadashi; Tohyama, Harukazu

    2016-03-21

    The objective of this work was to investigate the possibilities of using the wearable sensors-based H-Gait system in an actual clinical trial and proposes new gait parameters for characterizing OA gait. Seven H-Gait sensors, consisting of tri-axial inertial sensors, were attached to seven lower limb body segments (pelvis, both thighs, both shanks and both feet). The acceleration and angular velocity data measured were used to estimate three-dimensional kinematic parameters of patients during level walking. Three new parameters were proposed to assess the severity of OA based on the characteristics of these joint center trajectories in addition to conventional gait spatio-temporal parameters. The experiment was conducted on ten subjects with knee OA. The kinematic results obtained (hip, knee and ankle joint angles, joint trajectory in the horizontal and sagittal planes) were compared with those from a reference healthy (control) group. As a result, the angle between the right and left knee trajectories along with that of the ankle joint trajectories were almost twice as large (21.3° vs. 11.6° and 14.9° vs. 7.8°) compared to those of the healthy subjects. In conclusion, it was found that the ankle joints during stance abduct less to avoid adduction at the knee as the severity of OA increases and lead to more acute angles (less parallel) between the right and left knee/ankle joints in the horizontal plane. This method was capable to provide quantitative information about the gait of OA patients and has the advantage to allow for out-of-laboratory monitoring.

  19. Normative Spatiotemporal Gait Parameters in Older Adults

    PubMed Central

    Hollman, John H.; McDade, Eric M.; Petersen, Ronald C.

    2011-01-01

    While factor analyses have characterized pace, rhythm and variability as factors that explain variance in gait performance in older adults, comprehensive analyses incorporating many gait parameters have not been undertaken and normative data for many of those parameters are lacking. The purposes of this study were to conduct a factor analysis on nearly two dozen spatiotemporal gait parameters and to contribute to the normative database of gait parameters from healthy, able-bodied men and women over the age of 70. Data were extracted from 294 participants enrolled in the Mayo Clinic Study of Aging. Spatiotemporal gait data were obtained as participants completed two walks across a 5.6-m electronic walkway (GAITRite®). Five primary domains of spatiotemporal gait performance were identified: a “rhythm” domain was characterized by cadence and temporal parameters such as stride time; a “phase” domain was characterized by temporophasic parameters that constitute distinct divisions of the gait cycle; a “variability” domain encompassed gait cycle and step variability parameters; a “pace” domain was characterized by parameters that included gait speed, step length and stride length; and a “base of support” domain was characterized by step width and step width variability. Several domains differed between men and women and differed across age groups. Reference values of 23 gait parameters are presented which researchers or clinicians can use for assessing and interpreting gait dysfunction in aging persons. PMID:21531139

  20. Investigations on postural stability and spatiotemporal parameters of human gait using developed wearable smart insole.

    PubMed

    Das, Ratan; Kumar, Neelesh

    2015-01-01

    Measurement of spatiotemporal parameters of human gait is important for designing new, intelligent and efficient prosthetic and orthotic devices. The paper presents a novel application of smart insole for measuring force generated at various pressure points during dynamic gait on a human foot. Besides recording and analysing the spatiotemporal parameters during stance phase, the developed sensor is also used for development of active orthotic devices. Data from the sensors is analysed in LabVIEW software for detection of plantar force and temporal gait parameters. The smart instrumentation allows processing, display and storage of gait parameters and gait events in real time. Variations of pressure pattern reported by gait experiments can also be used in identifying an accidental fall. This information will be used as a feedback signal for controlling the motion of an indigenously developed gait assistive device, i.e. an active orthotic device. Pressure at the heel and great toe points is higher than the metatarsal heads during dynamic walk. It is higher at the heel and metatarsals points than the toe point during standing position.

  1. Toward a passive low-cost in-home gait assessment system for older adults.

    PubMed

    Wang, Fang; Stone, Erik; Skubic, Marjorie; Keller, James M; Abbott, Carmen; Rantz, Marilyn

    2013-03-01

    In this paper, we propose a webcam-based system for in-home gait assessment of older adults. A methodology has been developed to extract gait parameters including walking speed, step time, and step length from a 3-D voxel reconstruction, which is built from two calibrated webcam views. The gait parameters are validated with a GAITRite mat and a Vicon motion capture system in the laboratory with 13 participants and 44 tests, and again with GAITRite for 8 older adults in senior housing. Excellent agreement with intraclass correlation coefficients of 0.99 and repeatability coefficients between 0.7% and 6.6% was found for walking speed, step time, and step length given the limitation of frame rate and voxel resolution. The system was further tested with ten seniors in a scripted scenario representing everyday activities in an unstructured environment. The system results demonstrate the capability of being used as a daily gait assessment tool for fall risk assessment and other medical applications. Furthermore, we found that residents displayed different gait patterns during their clinical GAITRite tests compared to the realistic scenario, namely a mean increase of 21% in walking speed, a mean decrease of 12% in step time, and a mean increase of 6% in step length. These findings provide support for continuous gait assessment in the home for capturing habitual gait. PMID:24235111

  2. An Efficient Gait Recognition with Backpack Removal

    NASA Astrophysics Data System (ADS)

    Lee, Heesung; Hong, Sungjun; Kim, Euntai

    2009-12-01

    Gait-based human identification is a paradigm to recognize individuals using visual cues that characterize their walking motion. An important requirement for successful gait recognition is robustness to variations including different lighting conditions, poses, and walking speed. Deformation of the gait silhouette caused by objects carried by subjects also has a significant effect on the performance of gait recognition systems; a backpack is the most common of these objects. This paper proposes methods for eliminating the effect of a carried backpack for efficient gait recognition. We apply simple, recursive principal component analysis (PCA) reconstructions and error compensation to remove the backpack from the gait representation and then conduct gait recognition. Experiments performed with the CASIA database illustrate the performance of the proposed algorithm.

  3. Nonlinear dynamical model of human gait.

    PubMed

    West, Bruce J; Scafetta, Nicola

    2003-05-01

    We present a nonlinear dynamical model of the human gait control system in a variety of gait regimes. The stride-interval time series in normal human gait is characterized by slightly multifractal fluctuations. The fractal nature of the fluctuations becomes more pronounced under both an increase and decrease in the average gait. Moreover, the long-range memory in these fluctuations is lost when the gait is keyed on a metronome. Human locomotion is controlled by a network of neurons capable of producing a correlated syncopated output. The central nervous system is coupled to the motocontrol system, and together they control the locomotion of the gait cycle itself. The metronomic gait is simulated by a forced nonlinear oscillator with a periodic external force associated with the conscious act of walking in a particular way. PMID:12786188

  4. Nonlinear dynamical model of human gait

    NASA Astrophysics Data System (ADS)

    West, Bruce J.; Scafetta, Nicola

    2003-05-01

    We present a nonlinear dynamical model of the human gait control system in a variety of gait regimes. The stride-interval time series in normal human gait is characterized by slightly multifractal fluctuations. The fractal nature of the fluctuations becomes more pronounced under both an increase and decrease in the average gait. Moreover, the long-range memory in these fluctuations is lost when the gait is keyed on a metronome. Human locomotion is controlled by a network of neurons capable of producing a correlated syncopated output. The central nervous system is coupled to the motocontrol system, and together they control the locomotion of the gait cycle itself. The metronomic gait is simulated by a forced nonlinear oscillator with a periodic external force associated with the conscious act of walking in a particular way.

  5. Milestones in gait, balance, and falling.

    PubMed

    Nutt, John G; Horak, Fay B; Bloem, Bastiaan R

    2011-05-01

    Gait, balance, and falls have become increasingly common topics of published articles in the Movement Disorders journal since its launch in 1986. This growth represents an increasing awareness of the importance of mobility to patients' quality of life. New methods have become available that allow for accurate measurement of many aspects for gait and balance. This has led to new concepts of understanding gait and balance disorders. Neuroimaging has begun to reveal the neural circuitry underlying gait and balance. The physiology and pathophysiology of balance and gait are beginning to tease out the many processes involved in mobility and how they may be disrupted by disease processes. With these advances, the old therapeutic nihilism that characterized the clinician's approach to falls and gait disorders is disappearing, as innovative physiotherapy, exercise, drugs, and deep brain stimulation are being employed for gait and balance disorders. PMID:21626560

  6. Reflex Control of Robotic Gait Using Human Walking Data

    PubMed Central

    Macleod, Catherine A.; Meng, Lin; Conway, Bernard A.; Porr, Bernd

    2014-01-01

    Control of human walking is not thoroughly understood, which has implications in developing suitable strategies for the retraining of a functional gait following neurological injuries such as spinal cord injury (SCI). Bipedal robots allow us to investigate simple elements of the complex nervous system to quantify their contribution to motor control. RunBot is a bipedal robot which operates through reflexes without using central pattern generators or trajectory planning algorithms. Ground contact information from the feet is used to activate motors in the legs, generating a gait cycle visually similar to that of humans. Rather than developing a more complicated biologically realistic neural system to control the robot's stepping, we have instead further simplified our model by measuring the correlation between heel contact and leg muscle activity (EMG) in human subjects during walking and from this data created filter functions transferring the sensory data into motor actions. Adaptive filtering was used to identify the unknown transfer functions which translate the contact information into muscle activation signals. Our results show a causal relationship between ground contact information from the heel and EMG, which allows us to create a minimal, linear, analogue control system for controlling walking. The derived transfer functions were applied to RunBot II as a proof of concept. The gait cycle produced was stable and controlled, which is a positive indication that the transfer functions have potential for use in the control of assistive devices for the retraining of an efficient and effective gait with potential applications in SCI rehabilitation. PMID:25347544

  7. Reflex control of robotic gait using human walking data.

    PubMed

    Macleod, Catherine A; Meng, Lin; Conway, Bernard A; Porr, Bernd

    2014-01-01

    Control of human walking is not thoroughly understood, which has implications in developing suitable strategies for the retraining of a functional gait following neurological injuries such as spinal cord injury (SCI). Bipedal robots allow us to investigate simple elements of the complex nervous system to quantify their contribution to motor control. RunBot is a bipedal robot which operates through reflexes without using central pattern generators or trajectory planning algorithms. Ground contact information from the feet is used to activate motors in the legs, generating a gait cycle visually similar to that of humans. Rather than developing a more complicated biologically realistic neural system to control the robot's stepping, we have instead further simplified our model by measuring the correlation between heel contact and leg muscle activity (EMG) in human subjects during walking and from this data created filter functions transferring the sensory data into motor actions. Adaptive filtering was used to identify the unknown transfer functions which translate the contact information into muscle activation signals. Our results show a causal relationship between ground contact information from the heel and EMG, which allows us to create a minimal, linear, analogue control system for controlling walking. The derived transfer functions were applied to RunBot II as a proof of concept. The gait cycle produced was stable and controlled, which is a positive indication that the transfer functions have potential for use in the control of assistive devices for the retraining of an efficient and effective gait with potential applications in SCI rehabilitation. PMID:25347544

  8. Regional neuromuscular regulation within human rectus femoris muscle during gait.

    PubMed

    Watanabe, Kohei; Kouzaki, Motoki; Moritani, Toshio

    2014-11-01

    The spatial distribution pattern of neuromuscular activation within the human rectus femoris (RF) muscle was investigated during gait by multi-channel surface electromyography (surface EMG). Eleven healthy men walked on a treadmill with three gait speeds (4, 5, and 6 km/h) and gradients (0°, 12.5°, and 25°). The spatial distribution of surface EMG was tested by central locus activation (CLA), which is calculated from 2-D multi-channel surface EMG with 46 surface electrodes. For all conditions, CLA was around the middle regions during the swing-to-stance transition and moved in a proximal direction during the stance phase and stance-to-swing transition (p<0.05). CLA during the stance-to-swing transition and early swing phase significantly moved to proximal site with increasing gait speed (p<0.05). During the early stance and swing phases, with increasing grade, CLA significantly moved distally (p<0.05). These results suggest that the RF muscle is regionally activated during a gait cycle and is non-uniformly regulated longitudinally.

  9. Pneumatic interactive gait rehabilitation orthosis: design and preliminary testing.

    PubMed

    Belforte, G; Eula, G; Appendino, S; Sirolli, S

    2011-02-01

    Motor rehabilitation techniques based on passive movement of the lower limbs have been developed over the past 15 years. Gait training automation is the latest innovation in these techniques. This paper describes the design and development of a pneumatic interactive gait rehabilitation orthosis (PIGRO), as well as the first experimental results obtained with healthy subjects. PIGRO consists of a modular and size-adaptable exoskeleton, pneumatic actuation systems for the six actuated degrees of freedom (DoF), and a control unit. The foot orthosis and ankle actuation can be removed and/or replaced with orthopaedic shoes so as to permit gait rehabilitation while advancing between parallel bars with ground contact and partial body weight support (i.e. not walking in place). Control logic provides closed-loop position control independently on each joint, with position feedback for each joint in real time. Imposed curves are physiological joint angles: it is also possible to choose between activating one or both legs and to modify curves to obtain different gait patterns if required. The paper concludes with a presentation of experimental results for the device's performance.

  10. Patterns of pulmonary perfusion scans in normal subjects. IV. The prevalence of abnormal scans in smokers 30 to 49 years of age

    SciTech Connect

    Fedullo, P.F.; Kapitan, K.S.; Brewer, N.S.; Ashburn, W.L.; Hartman, M.T.; Moser, K.M.

    1989-05-01

    The usefulness of ventilation-perfusion scans in the diagnosis of pulmonary embolism is limited by the wide range of pulmonary diseases that are associated with abnormal scans, and by the largely undetermined prevalence of abnormal scans in persons without cardiopulmonary disease. In prior studies, we found perfusion defects to be rarely present in young persons and in older nonsmokers. To determine if normal older smokers have a higher prevalence of abnormal ventilation and perfusion scans, we performed six-view /sup 99m/Tc perfusion (Q) scans and /sup 133/Xe ventilation (V) scans in 40 subjects 30 to 49 yr of age who had no known cardiopulmonary disease. Each subject had undergone a history, physical examination, electrocardiogram, spirometry, and posteroanterior chest roentgenogram prior to scanning. All V and Q scans were interpreted blindly and independently by two experienced readers. No subject demonstrated a lobar or segmental defect on two views. One subject had a matched subsegmental defect, and one subject had delayed washout from a subsegmental area of the right upper lobe during V scanning, with a normal Q scan. We conclude that abnormal V and Q scans are uncommon among normal smokers 30 to 49 yr of age.

  11. Do sleep abnormalities and misaligned sleep/circadian rhythm patterns represent early clinical characteristics for developing psychosis in high risk populations?

    PubMed

    Zanini, Marcio; Castro, Juliana; Coelho, Fernando Morgadinho; Bittencourt, Lia; Bressan, Rodrigo A; Tufik, Sergio; Brietzke, Elisa

    2013-12-01

    Sleep architecture changes, such as slow-wave sleep (SWS) percentage variations and reductions in latency and density of rapid eye movement (REM), are found in most patients with schizophrenia and are considered to be an important part of the pathophysiology of the disorder. In addition to these sleep parameters changes, disruptions in sleep homeostasis and the sleep/circadian rhythm also occur in these patients. Sleep/circadian rhythm abnormalities negatively affect neocortical plasticity and cognition and often precede the diagnosis of the illness. Thus, it has been suggested that the sleep/circadian rhythm might be involved in the pathophysiology of psychosis. Recent advances in the identification of individuals at a high risk for developing schizophrenia allow us to investigate several neurobiological processes involved in the development of psychosis. In this article, we review the current evidence of the effects of sleep parameter abnormalities, disruptions in sleep homeostasis and misalignments of sleep circadian rhythm on the early stages of schizophrenia. In addition, we discuss the preliminary evidence of sleep and circadian rhythm abnormalities during the prodromal stages of psychosis and propose that these abnormalities can be explored as potential predictors, as an adjunct to clinical diagnosis, of developing a psychotic disorder in at risk populations.

  12. Influence of Spinal Cord Integrity on Gait Control in Human Spinal Cord Injury.

    PubMed

    Awai, Lea; Bolliger, Marc; Ferguson, Adam R; Courtine, Grégoire; Curt, Armin

    2016-07-01

    Background Clinical trials in spinal cord injury (SCI) primarily rely on simplified outcome metrics (ie, speed, distance) to obtain a global surrogate for the complex alterations of gait control. However, these assessments lack sufficient sensitivity to identify specific patterns of underlying impairment and to target more specific treatment interventions. Objective To disentangle the differential control of gait patterns following SCI beyond measures of time and distance. Methods The gait of 22 individuals with motor-incomplete SCI and 21 healthy controls was assessed using a high-resolution 3-dimensional motion tracking system and complemented by clinical and electrophysiological evaluations applying unbiased multivariate analysis. Results Motor-incomplete SCI patients showed varying degrees of spinal cord integrity (spinal conductivity) with severe limitations in walking speed and altered gait patterns. Principal component (PC) analysis applied on all the collected data uncovered robust coherence between parameters related to walking speed, distortion of intralimb coordination, and spinal cord integrity, explaining 45% of outcome variance (PC 1). Distinct from the first PC, the modulation of gait-cycle variables (step length, gait-cycle phases, cadence; PC 2) remained normal with respect to regained walking speed, whereas hip and knee ranges of motion were distinctly altered with respect to walking speed (PC 3). Conclusions In motor-incomplete SCI, distinct clusters of discretely controlled gait parameters can be discerned that refine the evaluation of gait impairment beyond outcomes of walking speed and distance. These findings are specifically different from that in other neurological disorders (stroke, Parkinson) and are more discrete at targeting and disentangling the complex effects of interventions to improve walking outcome following motor-incomplete SCI.

  13. Real-time gait analysis for diagnosing movement disorders

    NASA Astrophysics Data System (ADS)

    Green, Richard D.; Guan, Ling; Burne, J. A.

    1998-06-01

    This paper describes a video analysis system, free of markers and set-up procedures, that quantitatively identified gait abnormalities in real-time from standard video images. A novel color 3D body model was sized and texture mapped to the exact characteristics of a person from video images. The kinematics of the body model was represented by a transformation tree to track the position and orientation of a person relative to the camera. Joint angles were used to track the location and orientation of each body part, with the range of joint angles being constrained by associating degrees of freedom with each joint. To stabilize tracking, the joint angles were estimated for the next frame. The calculation of joint angles, for the next frame, was cast as an estimation problem which was solved using an iterated extended Kalman filter. Patients with dopa-responsive parkinsonism, and age matched normals, were video taped during several gait cycles with walking movements successfully tracked and classified. The results suggested that this approach has the potential to guide clinicians on the relative sensitivity of specific postural/gait features in diagnosis.

  14. Video analysis of gait for diagnosing movement disorders

    NASA Astrophysics Data System (ADS)

    Green, Richard D.; Guan, Ling; Burne, J. A.

    2000-01-01

    This paper describes a video analysis system, free of markers and setup procedures, that quantitatively identified gait abnormalities in real time from standard video images. A novel color 3D body model was sized and texture mapped to the exact characteristics of a person from video images. The kinematics of the body model was represented by a transformation tree to track the position and orientation of a person relative to the camera. Joint angles were used to track the location and orientation of each body part, with the range of joint angles being constrained by associating degrees of freedom with each joint. To stabilize tracking, the joint angles were estimated for the next frame. The calculation of joint angles, for the next frame, was cast as an estimation problem, which was solved using an iterated extended Kalman filter. Patients with dopa-responsive Parkinsonism, and age-matched normals, were video taped during several gait cycles with walking movements successfully tracked and classified. The results suggested that this approach has the potential to guide clinicians on the relative sensitivity of specific postural/gait features in diagnosis.

  15. Understanding the complexity of human gait dynamics

    NASA Astrophysics Data System (ADS)

    Scafetta, Nicola; Marchi, Damiano; West, Bruce J.

    2009-06-01

    Time series of human gait stride intervals exhibit fractal and multifractal properties under several conditions. Records from subjects walking at normal, slow, and fast pace speed are analyzed to determine changes in the fractal scalings as a function of the stress condition of the system. Records from subjects with different age from children to elderly and patients suffering from neurodegenerative disease are analyzed to determine changes in the fractal scalings as a function of the physical maturation or degeneration of the system. A supercentral pattern generator model is presented to simulate the above two properties that are typically found in dynamical network performance: that is, how a dynamical network responds to stress and to evolution.

  16. Understanding the complexity of human gait dynamics.

    PubMed

    Scafetta, Nicola; Marchi, Damiano; West, Bruce J

    2009-06-01

    Time series of human gait stride intervals exhibit fractal and multifractal properties under several conditions. Records from subjects walking at normal, slow, and fast pace speed are analyzed to determine changes in the fractal scalings as a function of the stress condition of the system. Records from subjects with different age from children to elderly and patients suffering from neurodegenerative disease are analyzed to determine changes in the fractal scalings as a function of the physical maturation or degeneration of the system. A supercentral pattern generator model is presented to simulate the above two properties that are typically found in dynamical network performance: that is, how a dynamical network responds to stress and to evolution. PMID:19566268

  17. Health Monitors for Chronic Disease by Gait Analysis with Mobile Phones

    PubMed Central

    Juen, Joshua; Cheng, Qian; Prieto-Centurion, Valentin; Krishnan, Jerry A.

    2014-01-01

    Abstract We have developed GaitTrack, a phone application to detect health status while the smartphone is carried normally. GaitTrack software monitors walking patterns, using only accelerometers embedded in phones to record spatiotemporal motion, without the need for sensors external to the phone. Our software transforms smartphones into health monitors, using eight parameters of phone motion transformed into body motion by the gait model. GaitTrack is designed to detect health status while the smartphone is carried during normal activities, namely, free-living walking. The current method for assessing free-living walking is medical accelerometers, so we present evidence that mobile phones running our software are more accurate. We then show our gait model is more accurate than medical pedometers for counting steps of patients with chronic disease. Our gait model was evaluated in a pilot study involving 30 patients with chronic lung disease. The six-minute walk test (6MWT) is a major assessment for chronic heart and lung disease, including congestive heart failure and especially chronic obstructive pulmonary disease (COPD), affecting millions of persons. The 6MWT consists of walking back and forth along a measured distance for 6 minutes. The gait model using linear regression performed with 94.13% accuracy in measuring walk distance, compared with the established standard of direct observation. We also evaluated a different statistical model using the same gait parameters to predict health status through lung function. This gait model has high accuracy when applied to demographic cohorts, for example, 89.22% accuracy testing the cohort of 12 female patients with ages 50–64 years. PMID:24694291

  18. Health monitors for chronic disease by gait analysis with mobile phones.

    PubMed

    Juen, Joshua; Cheng, Qian; Prieto-Centurion, Valentin; Krishnan, Jerry A; Schatz, Bruce

    2014-11-01

    We have developed GaitTrack, a phone application to detect health status while the smartphone is carried normally. GaitTrack software monitors walking patterns, using only accelerometers embedded in phones to record spatiotemporal motion, without the need for sensors external to the phone. Our software transforms smartphones into health monitors, using eight parameters of phone motion transformed into body motion by the gait model. GaitTrack is designed to detect health status while the smartphone is carried during normal activities, namely, free-living walking. The current method for assessing free-living walking is medical accelerometers, so we present evidence that mobile phones running our software are more accurate. We then show our gait model is more accurate than medical pedometers for counting steps of patients with chronic disease. Our gait model was evaluated in a pilot study involving 30 patients with chronic lung disease. The six-minute walk test (6 MWT) is a major assessment for chronic heart and lung disease, including congestive heart failure and especially chronic obstructive pulmonary disease (COPD), affecting millions of persons. The 6 MWT consists of walking back and forth along a measured distance for 6 minutes. The gait model using linear regression performed with 94.13% accuracy in measuring walk distance, compared with the established standard of direct observation. We also evaluated a different statistical model using the same gait parameters to predict health status through lung function. This gait model has high accuracy when applied to demographic cohorts, for example, 89.22% accuracy testing the cohort of 12 female patients with ages 50-64 years. PMID:24694291

  19. Validation of a standardised gait score to predict the healing of tibial fractures.

    PubMed

    Macri, F; Marques, L F; Backer, R C; Santos, M J; Belangero, W D

    2012-04-01

    There is no absolute method of evaluating healing of a fracture of the tibial shaft. In this study we sought to validate a new clinical method based on the systematic observation of gait, first by assessing the degree of agreement between three independent observers regarding the gait score for a given patient, and secondly by determining how such a score might predict healing of a fracture. We used a method of evaluating gait to assess 33 patients (29 men and four women, with a mean age of 29 years (15 to 62)) who had sustained an isolated fracture of the tibial shaft and had been treated with a locked intramedullary nail. There were 15 closed and 18 open fractures (three Gustilo and Anderson grade I, seven grade II, seven grade IIIA and one grade IIIB). Assessment was carried out three and six months post-operatively using videos taken with a digital camera. Gait was graded on a scale ranging from 1 (extreme difficulty) to 4 (normal gait). Bivariate analysis included analysis of variance to determine whether the gait score statistically correlated with previously validated and standardised scores of clinical status and radiological evidence of union. An association was found between the pattern of gait and all the other variables. Improvement in gait was associated with the absence of pain on weight-bearing, reduced tenderness over the fracture, a higher Radiographic Union Scale in Tibial Fractures score, and improved functional status, measured using the Brazilian version of the Short Musculoskeletal Function Assessment questionnaire (all p < 0.001). Although further study is needed, the analysis of gait in this way may prove to be a useful clinical tool. PMID:22434473

  20. Health monitors for chronic disease by gait analysis with mobile phones.

    PubMed

    Juen, Joshua; Cheng, Qian; Prieto-Centurion, Valentin; Krishnan, Jerry A; Schatz, Bruce

    2014-11-01

    We have developed GaitTrack, a phone application to detect health status while the smartphone is carried normally. GaitTrack software monitors walking patterns, using only accelerometers embedded in phones to record spatiotemporal motion, without the need for sensors external to the phone. Our software transforms smartphones into health monitors, using eight parameters of phone motion transformed into body motion by the gait model. GaitTrack is designed to detect health status while the smartphone is carried during normal activities, namely, free-living walking. The current method for assessing free-living walking is medical accelerometers, so we present evidence that mobile phones running our software are more accurate. We then show our gait model is more accurate than medical pedometers for counting steps of patients with chronic disease. Our gait model was evaluated in a pilot study involving 30 patients with chronic lung disease. The six-minute walk test (6 MWT) is a major assessment for chronic heart and lung disease, including congestive heart failure and especially chronic obstructive pulmonary disease (COPD), affecting millions of persons. The 6 MWT consists of walking back and forth along a measured distance for 6 minutes. The gait model using linear regression performed with 94.13% accuracy in measuring walk distance, compared with the established standard of direct observation. We also evaluated a different statistical model using the same gait parameters to predict health status through lung function. This gait model has high accuracy when applied to demographic cohorts, for example, 89.22% accuracy testing the cohort of 12 female patients with ages 50-64 years.

  1. Speed-Dependent Modulation of the Locomotor Behavior in Adult Mice Reveals Attractor and Transitional Gaits

    PubMed Central

    Lemieux, Maxime; Josset, Nicolas; Roussel, Marie; Couraud, Sébastien; Bretzner, Frédéric

    2016-01-01

    Locomotion results from an interplay between biomechanical constraints of the muscles attached to the skeleton and the neuronal circuits controlling and coordinating muscle activities. Quadrupeds exhibit a wide range of locomotor gaits. Given our advances in the genetic identification of spinal and supraspinal circuits important to locomotion in the mouse, it is now important to get a better understanding of the full repertoire of gaits in the freely walking mouse. To assess this range, young adult C57BL/6J mice were trained to walk and run on a treadmill at different locomotor speeds. Instead of using the classical paradigm defining gaits according to their footfall pattern, we combined the inter-limb coupling and the duty cycle of the stance phase, thus identifying several types of gaits: lateral walk, trot, out-of-phase walk, rotary gallop, transverse gallop, hop, half-bound, and full-bound. Out-of-phase walk, trot, and full-bound were robust and appeared to function as attractor gaits (i.e., a state to which the network flows and stabilizes) at low, intermediate, and high speeds respectively. In contrast, lateral walk, hop, transverse gallop, rotary gallop, and half-bound were more transient and therefore considered transitional gaits (i.e., a labile state of the network from which it flows to the attractor state). Surprisingly, lateral walk was less frequently observed. Using graph analysis, we demonstrated that transitions between gaits were predictable, not random. In summary, the wild-type mouse exhibits a wider repertoire of locomotor gaits than expected. Future locomotor studies should benefit from this paradigm in assessing transgenic mice or wild-type mice with neurotraumatic injury or neurodegenerative disease affecting gait. PMID:26941592

  2. Muscle force modification strategies are not consistent for gait retraining to reduce the knee adduction moment in individuals with knee osteoarthritis.

    PubMed

    Shull, Peter B; Huang, Yangjian; Schlotman, Taylor; Reinbolt, Jeffrey A

    2015-09-18

    While gait retraining paradigms that alter knee loads typically focus on modifying kinematics, the underlying muscle force modifications responsible for these kinematic changes remain largely unknown. As humans are generally thought to select uniform gait muscle patterns such as strategies based on fatigue cost functions or energy minimization, we hypothesized that a kinematic gait change known to reduce the knee adduction moment (i.e. toe-in gait) would be accompanied by a uniform muscle force modification strategy for individuals with symptomatic knee osteoarthritis. Ten subjects with self-reported knee pain and radiographic evidence of medial compartment knee osteoarthritis performed normal gait and toe-in gait modification walking trials. Two hundred muscle-actuated dynamic simulations (10 steps for normal gait and 10 steps from toe-in gait for each subject) were performed to determine muscle forces for each gait. Results showed that subjects internally rotated their feet during toe-in gait, which decreased the foot progression angle by 7° (p<0.01) and reduced the first peak knee adduction moment by 20% (p<0.01). While significant muscle force modifications were evidenced within individuals, there were no consistent muscle force modifications across all subjects. It may be that self-selected muscle pattern changes are not uniform for gait modification particularly for individuals with knee pain. Future studies focused on altering knee loads should not assume consistent muscle force modifications for a given kinematic gait change across subjects and should consider muscle forces in addition to kinematics in gait retraining paradigms.

  3. Joint contact forces can be reduced by improving joint moment symmetry in below-knee amputee gait simulations.

    PubMed

    Koelewijn, Anne D; van den Bogert, Antonie J

    2016-09-01

    Despite having a fully functional knee and hip in both legs, asymmetries in joint moments of the knee and hip are often seen in gait of persons with a unilateral transtibial amputation (TTA), possibly resulting in excessive joint loading. We hypothesize that persons with a TTA can walk with more symmetric joint moments at the cost of increased effort or abnormal kinematics. The hypothesis was tested using predictive simulations of gait. Open loop controls of one gait cycle were found by solving an optimization problem that minimizes a combination of walking effort and tracking error in joint angles, ground reaction force and gait cycle duration. A second objective was added to penalize joint moment asymmetry, creating a multi-objective optimization problem. A Pareto front was constructed by changing the weights of the objectives and three solutions were analyzed to study the effect of increasing joint moment symmetry. When the optimization placed more weight on moment symmetry, walking effort increased and kinematics became less normal, confirming the hypothesis. TTA gait improved with a moderate increase in joint moment symmetry. At a small cost of effort and abnormal kinematics, the peak hip extension moment in the intact leg was decreased significantly, and so was the joint contact force in the knee and hip. Additional symmetry required a significant increase in walking effort and the joint contact forces in both hips became significantly higher than in able-bodied gait.

  4. NUP98/JARID1A is a novel recurrent abnormality in pediatric acute megakaryoblastic leukemia with a distinct HOX gene expression pattern.

    PubMed

    de Rooij, J D E; Hollink, I H I M; Arentsen-Peters, S T C J M; van Galen, J F; Berna Beverloo, H; Baruchel, A; Trka, J; Reinhardt, D; Sonneveld, E; Zimmermann, M; Alonzo, T A; Pieters, R; Meshinchi, S; van den Heuvel-Eibrink, M M; Zwaan, C Michel

    2013-12-01

    Cytogenetic abnormalities and early response to treatment are the main prognostic factors in acute myeloid leukemia (AML). Recently, NUP98/NSD1 (t(5; 11)(q35; p15)), a cytogenetically cryptic fusion, was described as recurrent event in AML, characterized by dismal prognosis and HOXA/B gene overexpression. Using split-signal fluorescence in situ hybridization, other NUP98-rearranged pediatric AML cases were identified, including several acute megakaryoblastic leukemia (AMKL) cases with a cytogenetically cryptic fusion of NUP98 to JARID1A (t(11;15)(p15;q35)). In this study we screened 105 pediatric AMKL cases to analyze the frequency of NUP98/JARID1A and other recurrent genetic abnormalities. NUP98/JARID1A was identified in 11/105 patients (10.5%). Other abnormalities consisted of RBM15/MKL1 (n=16), CBFA2T3/GLIS2 (n=13) and MLL-rearrangements (n=13). Comparing NUP98/JARID1A-positive patients with other pediatric AMKL patients, no significant differences in sex, age and white blood cell count were found. NUP98/JARID1A was not an independent prognostic factor for 5-year overall (probability of overall survival (pOS)) or event-free survival (probability of event-free survival (pEFS)), although the 5-year pOS for the entire AMKL cohort was poor (42 ± 6%). Cases with RBM15/MLK1 fared significantly better in terms of pOS and pEFS, although this was not independent from other risk factors in multivariate analysis. NUP98/JARID1A cases were characterized by HOXA/B gene overexpression, which is a potential druggable pathway. In conclusion, NUP98/JARID1A is a novel recurrent genetic abnormality in pediatric AMKL.

  5. Analysis of toddlers' gait after six months of independent walking to identify autism: a preliminary study.

    PubMed

    Esposito, Gianluca; Venuti, Paola

    2008-02-01

    This research analyzed gait in toddlers and tested the hypothesis that movement can be used as an early indicator of Autistic Disorder. It was proposed that an early identification method could indicate differences in the gait of toddlers with autism as opposed to those with typical development or with mental retardation. Observational methods were applied to retrospective home videos of 42 children after 6 mo. of independent walking. In particular, the Walking Observation Scale was used, which includes 11 items that analyze gait through three axes of foot movements, arm movements, and global movements. Analysis showed different distributions for the three groups, i.e., the autistic group differed from the other two on scores for the Walking Observation Scale and each axis. After 6 mo. of independent walking, different patterns in gait among groups were evident. These results agree with recently published evidence which acknowledges the importance of movement as an early indicator for differential diagnosis of autism. PMID:18459375

  6. A multi-channel biomimetic neuroprosthesis to support treadmill gait training in stroke patients.

    PubMed

    Chia, Noelia; Ambrosini, Emilia; Baccinelli, Walter; Nardone, Antonio; Monticone, Marco; Ferrigno, Giancarlo; Pedrocchi, Alessandra; Ferrante, Simona

    2015-01-01

    This study presents an innovative multi-channel neuroprosthesis that induces a biomimetic activation of the main lower-limb muscles during treadmill gait training to be used in the rehabilitation of stroke patients. The electrostimulation strategy replicates the physiological muscle synergies used by healthy subjects to walk on a treadmill at their self-selected speed. This strategy is mapped to the current gait sub-phases, which are identified in real time by a custom algorithm. This algorithm divides the gait cycle into six sub-phases, based on two inertial sensors placed laterally on the shanks. Therefore, the pre-defined stimulation profiles are expanded or stretched based on the actual gait pattern of each single subject. A preliminary experimental protocol, involving 10 healthy volunteers, was carried out to extract the muscle synergies and validate the gait-detection algorithm, which were afterwards used in the development of the neuroprosthesis. The feasibility of the neuroprosthesis was tested on one healthy subject who simulated different gait patterns, and a chronic stroke patient. The results showed the correct functioning of the system. A pilot study of the neurorehabilitation treatment for stroke patients is currently being carried out.

  7. Longitudinal assessment of neuropsychological and temporal/spatial gait characteristics of elderly fallers: taking it all in stride.

    PubMed

    MacAulay, Rebecca K; Allaire, Ted D; Brouillette, Robert M; Foil, Heather C; Bruce-Keller, Annadora J; Han, Hongmei; Johnson, William D; Keller, Jeffrey N

    2015-01-01

    Gait abnormalities are linked to cognitive decline and an increased fall risk within older adults. The present study addressed gaps from cross-sectional studies in the literature by longitudinally examining the interplay between temporal and spatial aspects of gait, cognitive function, age, and lower-extremity strength in elderly "fallers" and "non-fallers". Gait characteristics, neuropsychological and physical test performance were examined at two time points spaced a year apart in cognitively intact individuals aged 60 and older (N = 416). Mixed-model repeated-measure ANCOVAs examined temporal (step time) and spatial (stride length) gait characteristics during a simple and cognitive-load walking task in fallers as compared to non-fallers. Fallers consistently demonstrated significant alterations in spatial, but not temporal, aspects of gait as compared to non-fallers during both walking tasks. Step time became slower as stride length shortened amongst all participants during the dual task. Shorter strides and slower step times during the dual task were both predicted by worse executive attention/processing speed performance. In summary, divided attention significantly impacts spatial aspects of gait in "fallers", suggesting stride length changes may precede declines in other neuropsychological and gait characteristics, thereby selectively increasing fall risk. Our results indicate that multimodal intervention approaches that integrate physical and cognitive remediation strategies may increase the effectiveness of fall risk interventions. PMID:25852548

  8. Progressive frontal gait disturbance with atypical Alzheimer's disease and corticobasal degeneration

    PubMed Central

    Rossor, M; Tyrrell, P; Warrington, E; Thompson, P; Marsden, C; Lantos, P

    1999-01-01

    OBJECTIVES—The clinical neuropsychological, neuroradiological, and neuropathological description of two patients presenting with a frontal gait disturbance.
METHODS—Clinical case note review, neuropsychological assessment, functional imaging with 15O2 and 18F-fluorodopa PET, and neuropathology.
RESULTS—Both patients presented with frontal gait impairment and only later developed more widespread cognitive impairment. In both cases 15O2 PET disclosed focal hypometabolism in the medial frontal lobes and in one patient 18F-fluorodopa uptake into the caudate and putamen was normal. The neuropathological examination in one patient showed Alzheimer's histopathology together with large swollen eosinophilic neurons characteristic of corticobasal degeneration, which were particularly prominent in the medial frontal lobes.
CONCLUSION—Focal degeneration of the medial frontal lobes may present as an isolated gait disturbance and should be considered in the differential diagnosis of patients who present without an obvious structural abnormality on neuroimaging.

 PMID:10449557

  9. A characterization of Parkinson's disease by describing the visual field motion during gait

    NASA Astrophysics Data System (ADS)

    Trujillo, David; Martínez, Fabio; Atehortúa, Angélica; Alvarez, Charlens; Romero, Eduardo

    2015-12-01

    An early diagnosis of Parkinson's Disease (PD) is crucial towards devising successful rehabilitation programs. Typically, the PD diagnosis is performed by characterizing typical symptoms, namely bradykinesia, rigidity, tremor, postural instability or freezing gait. However, traditional examination tests are usually incapable of detecting slight motor changes, specially for early stages of the pathology. Recently, eye movement abnormalities have correlated with early onset of some neurodegenerative disorders. This work introduces a new characterization of the Parkinson disease by describing the ocular motion during a common daily activity as the gait. This paper proposes a fully automatic eye motion analysis using a dense optical flow that tracks the ocular direction. The eye motion is then summarized using orientation histograms constructed during a whole gait cycle. The proposed approach was evaluated by measuring the χ2 distance between the orientation histograms, showing substantial differences between control and PD patients.

  10. 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.

  11. Human identification using temporal information preserving gait template.

    PubMed

    Wang, Chen; Zhang, Junping; Wang, Liang; Pu, Jian; Yuan, Xiaoru

    2012-11-01

    Gait Energy Image (GEI) is an efficient template for human identification by gait. However, such a template loses temporal information in a gait sequence, which is critical to the performance of gait recognition. To address this issue, we develop a novel temporal template, named Chrono-Gait Image (CGI), in this paper. The proposed CGI template first extracts the contour in each gait frame, followed by encoding each of the gait contour images in the same gait sequence with a multichannel mapping function and compositing them to a single CGI. To make the templates robust to a complex surrounding environment, we also propose CGI-based real and synthetic temporal information preserving templates by using different gait periods and contour distortion techniques. Extensive experiments on three benchmark gait databases indicate that, compared with the recently published gait recognition approaches, our CGI-based temporal information preserving approach achieves competitive performance in gait recognition with robustness and efficiency. PMID:22201053

  12. Accelerometry-based gait analysis and its application to Parkinson's disease assessment--part 1: detection of stride event.

    PubMed

    Yoneyama, Mitsuru; Kurihara, Yosuke; Watanabe, Kajiro; Mitoma, Hiroshi

    2014-05-01

    Gait analysis is widely recognized as a promising tool for obtaining objective information on the walking behavior of Parkinson's disease (PD) patients. It is especially useful in clinical practices if gait properties can be captured with minimal instrumentation that does not interfere with the subject's usual behavioral pattern under ambulatory conditions. In this study, we propose a new gait analysis system based on a trunk-mounted acceleration sensor and automatic gait detection algorithm. The algorithm identifies the acceleration signal with high intensity, periodicity, and biphasicity as a possible gait sequence, from which gait peaks due to stride events are extracted by utilizing the cross-correlation and anisotropy properties of the signal. A total of 11 healthy subjects and 12 PD patients were tested to evaluate the performance of the algorithm. The result indicates that gait peaks can be detected with an accuracy of more than 94%. The proposed method may serve as a practical component in the accelerometry-based assessment of daily gait characteristics.

  13. The Effect of Two Different Cognitive Tests on Gait Parameters during Dual Tasks in Healthy Postmenopausal Women

    PubMed Central

    Kałużny, Krystian; Hagner, Wojciech; Kałużna, Anna; Kochański, Bartosz; Borkowska, Alina; Budzyński, Jacek

    2016-01-01

    Introduction. The paper aims to evaluate the influence of two different demanding cognitive tasks on gait parameters using BTS SMART system analysis. Patients and Methods. The study comprised 53 postmenopausal women aged 64.5 ± 6.7 years (range: 47–79). For every subject, gait analysis using a BTS SMART system was performed in a dual-task study design under three conditions: (I) while walking only (single task), (II) walking while performing a simultaneous simple cognitive task (SCT) (dual task), and (III) walking while performing a simultaneous complex cognitive task (CCT) (dual task). Time-space parameters of gait pertaining to the length of a single support phase, double support phase, gait speed, step length, step width, and leg swing speed were analyzed. Results. Performance of cognitive tests during gait resulted in a statistically significant prolongation of the left (by 7%) and right (by 7%) foot gait cycle, shortening of the length of steps made with the right extremity (by 4%), reduction of speed of swings made with the left (by 11%) and right (by 8%) extremity, and reduction in gait speed (by 6%). Conclusions. Performance of cognitive tests during gait changes its individual pattern in relation to the level of the difficulty of the task. PMID:27022602

  14. The role of altered proximal femoral geometry in impaired pelvis stability and hip control during CP gait: A simulation study.

    PubMed

    Bosmans, Lode; Jansen, Karen; Wesseling, Mariska; Molenaers, Guy; Scheys, Lennart; Jonkers, Ilse

    2016-02-01

    Children with cerebral palsy (CP) often present aberrant hip geometry, more specifically increased femoral anteversion and neck-shaft angle. Furthermore, altered gait patterns are present within this population. This study analyzed the effect of aberrant femoral geometry, as present in subjects with CP, on the ability of muscles to control hip and knee joint kinematics. Given the specific gait deficits observed during crouch gait, increased ability to abduct, externally rotate the hip and extend the knee and hip were denoted as beneficial effects. We ran dynamic simulations of CP and normal gait using two musculoskeletal models, one reflecting normal femoral geometry and one reflecting proximal femoral deformities. The results show that the combination of aberrant bone geometry and CP-specific gait characteristics beneficially increased the ability of gluteus medius and maximus to extend the hip and knee. In contrast, the potentials of the hamstrings to extend the hip decreased whereas the potentials to flex the knee increased. These changes closely followed the observed changes in the muscle moment arm lengths. In conclusion, this study emphasizes the concomitant effect of the presence of proximal femoral deformity and CP gait characteristics on the muscle control of hip and knee joint kinematics during single stance. Not accounting for subject-specific geometry will affect the calculated muscles' potential during gait. Therefore, the use of generic models to assess muscle function in the presence of femoral deformity and CP gait should be treated with caution.

  15. Lever arm dysfunction in cerebral palsy gait.

    PubMed

    Theologis, Tim

    2013-11-01

    Skeletal structures act as lever arms during walking. Muscle activity and the ground reaction against gravity exert forces on the skeleton, which generate torque (moments) around joints. These lead to the sequence of movements which form normal human gait. Skeletal deformities in cerebral palsy (CP) affect the function of bones as lever arms and compromise gait. Lever arm dysfunction should be carefully considered when contemplating treatment to improve gait in children with CP.

  16. Mobile inertial sensor based gait analysis: Validity and reliability of spatiotemporal gait characteristics in healthy seniors.

    PubMed

    Donath, Lars; Faude, Oliver; Lichtenstein, Eric; Pagenstert, Geert; Nüesch, Corina; Mündermann, Annegret

    2016-09-01

    Gait analysis is commonly used to identify gait changes and fall risk in clinical populations and seniors. Body-worn inertial sensor based gait analyses provide a feasible alternative to optometric and pressure based measurements of spatiotemporal gait characteristics. We assessed validity and relative and absolute reliability of a body-worn inertial sensor system (RehaGait(®)) for measuring spatiotemporal gait characteristics compared to a standard stationary treadmill (Zebris(®)). Spatiotemporal gait parameters (walking speed, stride length, cadence and stride time) were collected for 24 healthy seniors (age: 75.3±6.7 years) tested on 2 days (1 week apart) simultaneously using the sensor based system and instrumented treadmill. Each participant completed walking tests (200 strides) at different walking speeds and slopes. The difference between the RehaGait(®) system and the treadmill was trivial (Cohen's d<0.2) except for speed and stride length at slow speed (Cohen's d, 0.35 and 0.49, respectively). Intraclass correlation coefficients (ICC) were excellent for temporal gait characteristics (cadence and stride time; ICC: 0.99-1.00) and moderate for stride length (ICC: 0.73-0.89). Both devices had excellent day-to-day reliability for all gait parameters (ICC: 0.82-0.99) except for stride length at slow speed (ICC: 0.74). The RehaGait(®) is a valid and reliable tool for assessing spatiotemporal gait parameters for treadmill walking at different speeds and slopes. PMID:27494305

  17. Comparison of trunk activity during gait initiation and walking in humans.

    PubMed

    Ceccato, Jean-Charles; de Sèze, Mathieu; Azevedo, Christine; Cazalets, Jean-René

    2009-12-07

    To understand the role of trunk muscles in maintenance of dynamic postural equilibrium we investigate trunk movements during gait initiation and walking, performing trunk kinematics analysis, Erector spinae muscle (ES) recordings and dynamic analysis. ES muscle expressed a metachronal descending pattern of activity during walking and gait initiation. In the frontal and horizontal planes, lateroflexion and rotation occur before in the upper trunk and after in the lower trunk. Comparison of ES muscle EMGs and trunk kinematics showed that trunk muscle activity precedes corresponding kinematics activity, indicating that the ES drive trunk movement during locomotion and thereby allowing a better pelvis mobilization. EMG data showed that ES activity anticipates propulsive phases in walking with a repetitive pattern, suggesting a programmed control by a central pattern generator. Our findings also suggest that the programs for gait initiation and walking overlap with the latter beginning before the first has ended.

  18. Curve aligning approach for gait authentication based on a wearable accelerometer.

    PubMed

    Sun, Hu; Yuao, Tao

    2012-06-01

    Gait authentication based on a wearable accelerometer is a novel biometric which can be used for identity identification, medical rehabilitation and early detection of neurological disorders. The method for matching gait patterns tells heavily on authentication performances. In this paper, curve aligning is introduced as a new method for matching gait patterns and it is compared with correlation and dynamic time warping (DTW). A support vector machine (SVM) is proposed to fuse pattern-matching methods in a decision level. Accelerations collected from ankles of 22 walking subjects are processed for authentications in our experiments. The fusion of curve aligning with backward-forward accelerations and DTW with vertical accelerations promotes authentication performances substantially and consistently. This fusion algorithm is tested repeatedly. Its mean and standard deviation of equal error rates are 0.794% and 0.696%, respectively, whereas among all presented non-fusion algorithms, the best one shows an EER of 3.03%. PMID:22621972

  19. Comparison of Trunk Activity during Gait Initiation and Walking in Humans

    PubMed Central

    Azevedo, Christine; Cazalets, Jean-René

    2009-01-01

    To understand the role of trunk muscles in maintenance of dynamic postural equilibrium we investigate trunk movements during gait initiation and walking, performing trunk kinematics analysis, Erector spinae muscle (ES) recordings and dynamic analysis. ES muscle expressed a metachronal descending pattern of activity during walking and gait initiation. In the frontal and horizontal planes, lateroflexion and rotation occur before in the upper trunk and after in the lower trunk. Comparison of ES muscle EMGs and trunk kinematics showed that trunk muscle activity precedes corresponding kinematics activity, indicating that the ES drive trunk movement during locomotion and thereby allowing a better pelvis mobilization. EMG data showed that ES activity anticipates propulsive phases in walking with a repetitive pattern, suggesting a programmed control by a central pattern generator. Our findings also suggest that the programs for gait initiation and walking overlap with the latter beginning before the first has ended. PMID:19997606

  20. The effect of total knee arthroplasty on knee joint kinematics and kinetics during gait.

    PubMed

    Hatfield, Gillian L; Hubley-Kozey, Cheryl L; Astephen Wilson, Janie L; Dunbar, Michael J

    2011-02-01

    This study determined how total knee arthroplasty (TKA) altered knee motion and loading during gait. Three-dimensional kinematic and kinetic gait patterns of 42 patients with severe knee osteoarthritis were collected 1 week prior and 1-year post-TKA. Principal component analysis extracted major patterns of variability in the gait waveforms. Overall and midstance knee adduction moment magnitude decreased. Overall knee flexion angle magnitude increased due to an increase during swing. Increases in the early stance knee flexion moment and late stance knee extension moment were found, indicating improved impact attenuation and function. A decrease in the early stance knee external rotation moment indicated alteration in the typical rotation mechanism. Most changes moved toward an asymptomatic pattern and would be considered improvements in motion, function, and loading.

  1. The Pathomechanics Of Calcaneal Gait

    NASA Astrophysics Data System (ADS)

    Sutherland, David H.; Cooper, Les

    1980-07-01

    The data acquisition system employed in our laboratory includes optical, electronic and computer subsystems. Three movie camera freeze the motion for analysis. The film is displayed on a motion analyzer, and the body segment positions are recorded in a three dimensional coordinate system with Graf/pen sonic digitizer. The angular rotations are calculated by computer and automatically plotted. The force plate provides measurements of vertical force, foreaft shear, medial-lateral shear, torque, and center of pressure. Electromyograms are superimposed upon gait movies to permit measurement of muscle phasic activity. The Hycam movie camera si-multaneously films (through separate lens) the subject and oscilloscope. Movement measurements, electromyograms, and floor reaction forces provide the data base for analysis. From a study of the gait changes in five normal subjects following tibial nerve block, and from additional studies of patients with paralysis of the ankle plantar flexors, the pathomechanics of calcaneal gait can be described. Inability to transfer weight to the forward part of the foot produces ankle instability and reduction of contralateral step length. Excessive drop of the center of mass necessitates com-pensatory increased lift energy output through the sound limb to restore the height of the center of mass. Excessive stance phase ankle dorsiflexion produces knee instability requiring prolonged quadriceps muscle phasic activity.

  2. Optics in gait analysis and anthropometry

    NASA Astrophysics Data System (ADS)

    Silva Moreno, Alejandra Alicia

    2013-11-01

    Since antiquity, human gait has been studied to understand human movement, the kind of gait, in some cases, can cause musculoskeletal disorders or other health problems; in addition, also from antiquity, anthropometry has been important for the design of human items such as workspaces, tools, garments, among others. Nowadays, thanks to the development of optics and electronics, more accurate studies of gait and anthropometry can be developed. This work will describe the most important parameters for gait analysis, anthropometry and the optical systems used.

  3. Mixed gaits in small avian terrestrial locomotion

    PubMed Central

    Andrada, Emanuel; Haase, Daniel; Sutedja, Yefta; Nyakatura, John A.; M. Kilbourne, Brandon; Denzler, Joachim; Fischer, Martin S.; Blickhan, Reinhard

    2015-01-01

    Scientists have historically categorized gaits discretely (e.g. regular gaits such as walking, running). However, previous results suggest that animals such as birds might mix or regularly or stochastically switch between gaits while maintaining a steady locomotor speed. Here, we combined a novel and completely automated large-scale study (over one million frames) on motions of the center of mass in several bird species (quail, oystercatcher, northern lapwing, pigeon, and avocet) with numerical simulations. The birds studied do not strictly prefer walking mechanics at lower speeds or running mechanics at higher speeds. Moreover, our results clearly display that the birds in our study employ mixed gaits (such as one step walking followed by one step using running mechanics) more often than walking and, surprisingly, maybe as often as grounded running. Using a bio-inspired model based on parameters obtained from real quails, we found two types of stable mixed gaits. In the first, both legs exhibit different gait mechanics, whereas in the second, legs gradually alternate from one gait mechanics into the other. Interestingly, mixed gaits parameters mostly overlap those of grounded running. Thus, perturbations or changes in the state induce a switch from grounded running to mixed gaits or vice versa. PMID:26333477

  4. Robot-assisted modifications of gait in healthy individuals.

    PubMed

    Kim, Seok Hun; Banala, Sai K; Brackbill, Elizabeth A; Agrawal, Sunil K; Krishnamoorthy, Vijaya; Scholz, John P

    2010-05-01

    This study investigated whether short-term modifications of gait could be induced in healthy adults and whether a combination of kinetic (a compliant force resisting deviation of the foot from the prescribed footpath) and visual guidance was superior to either kinetic guidance or visual guidance alone in producing this modification. Thirty-nine healthy adults, 20-33 years old, were randomly assigned to the three groups receiving six 10-min blocks of treadmill training requiring them to modify their footpath to match a scaled-down path. Changes of the footpath, specific joint events and joint moments were analyzed. Persons receiving combined kinetic and visual guidance showed larger modifications of their gait patterns that were maintained longer, persisting up to 2 h after intervening over-ground activities, than did persons receiving training with primarily kinetic guidance or with visual guidance alone. The results emphasize the short-term plasticity of locomotor circuits and provide a possible basis for persons learning to achieve more functional gait patterns following a stroke or other neurological disorders.

  5. Abnormalities of CSF flow patterns in the cerebral aqueduct in treatment-resistant late-life depression: a potential biomarker of microvascular angiopathy.

    PubMed

    Naish, Josephine H; Baldwin, Robert C; Patankar, Tufail; Jeffries, Suzanne; Burns, Alistair S; Taylor, Christopher J; Waterton, John C; Jackson, Alan

    2006-09-01

    There is growing evidence that microvascular angiopathy (MVA) plays an important role in the development of dementia and affective disorders in older people. At currently available image resolutions it is not possible to image directly the vascular changes associated with MVA, but the effects on blood and cerebrospinal fluid (CSF) flow may be detectable. The aim of this study was to investigate a potential biomarker for MVA based on MRI of abnormalities in CSF flow. Since there is considerable indirect evidence that treatment resistance in late-onset depressive disorder is related to MVA, we assessed the method in a group of 22 normal volunteers and 29 patients with responsive (N=21) or treatment-resistant (N=8) late-onset depressive disorder. Single-slice quantified phase-contrast (PC) images of cerebral blood and CSF flow were collected at 15 points over a cardiac cycle, and the resulting flow curves were parameterized. Significant differences in the CSF flow (width of systolic flow peak and diastolic flow volume, both P<0.01) through the cerebral aqueduct were observed for the group of treatment-resistant patients when compared to age matched controls. No significant difference was observed for a group of 21 patients with treatment-responsive depression. The findings support the hypothesis that MR measurement of CSF flow abnormalities provides a biomarker of MVA, and thus could have application in a wide range of age-related diseases.

  6. [Gait analysis after intra-articular calcaneus fractures].

    PubMed

    Siegmeth, A; Petje, G; Mittlmeier, T; Vécsei, V

    1996-01-01

    We retrospectively compared 20 patients with displaced intra-articular calcaneal fractures by clinical assessment and dynamic pedography. Eleven were treated operatively, 9 conservatively. The purpose was to identify differences in post-traumatic gait performance and to correlate the pedographic data to a clinical score to show its reliability. Twenty individuals without a history of foot injuries were used as a control group. Both groups had restricted motion in the subtalar joint, increased hindfoot and midfoot loading and decreased forefoot loading. Furthermore, they showed prolonged contact phases and an impaired ability to speed up gait during the toe-off phase. Load transfer from the hindfoot to the forefoot showed typical distribution patterns. The operatively treated group showed better functional results with fewer subjective complaints.

  7. The biomechanics of pathological gait - from muscle to movement.

    PubMed

    Stewart, Caroline; Shortland, Adam P

    2010-01-01

    Clinicians face the daily challenge of assessing and treating patients with gait problems. Musculoskeletal models appear to show potential for assisting with the understanding of complex pathological movements, however they are also complex and reliant on multiple assumptions in order to maintain stability. This paper breaks down the process by which muscles produce movement into a series of steps. The contributions and limitations of modelling each separate step are then considered. The calf muscles serve as an illustration throughout the paper, as these muscles are frequently implicated in the development of pathological gait patterns. An argument is put forward for the development of a range of tools for use in clinical practice, leading to an enhanced appreciation of the importance of joint moments. Improved clinical understanding of the link between muscles and movement will allow clinicians to develop better treatment plans for their patients.

  8. Gait deviations and compensations in pediatric patients with increased femoral torsion.

    PubMed

    Bruderer-Hofstetter, Marina; Fenner, Verena; Payne, Erika; Zdenek, Katja; Klima, Harry; Wegener, Regina

    2015-02-01

    Coxa antetorta describes an abnormal torsion of the femur. It is commonly considered a cosmetic problem and is treated surgically only in severe cases and the presence of physical complaints. The purpose of this study was to identify deviations in gait kinematics and kinetics in pediatric patients caused by coxa antetorta and to categorize these deviations into primary and secondary deviations. We conducted a retrospective, cross-sectional three-dimensional (3D) gait analysis study to detect gait deviations in adolescents (n = 18; age range 10.5-17.5 years) with coxa antetorta compared to age-matched healthy control subjects (n = 17). Principal component (PC) analysis was used for data reduction. Linear mixed models applied to PC-scores were used to estimate the main effects within retained PCs followed by a post-hoc subgroup analysis. Patients walked with smaller external foot progression angle, greater knee adduction, more internally rotated and flexed hips and greater anterior pelvic tilt. Subgroup analysis revealed that-depending on knee alignment-patients had higher knee and hip adduction moments. These deviations in joint kinematics and kinetics may be associated with physical complaints and accelerated development of osteoarthritis. Assessment of gait deviations related to coxa antetorta using 3D gait analysis may be an additional tool in individual clinical decision-making.

  9. Assessing interactions among multiple physiological systems during walking outside a laboratory: An Android based gait monitor.

    PubMed

    Sejdić, E; Millecamps, A; Teoli, J; Rothfuss, M A; Franconi, N G; Perera, S; Jones, A K; Brach, J S; Mickle, M H

    2015-12-01

    Gait function is traditionally assessed using well-lit, unobstructed walkways with minimal distractions. In patients with subclinical physiological abnormalities, these conditions may not provide enough stress on their ability to adapt to walking. The introduction of challenging walking conditions in gait can induce responses in physiological systems in addition to the locomotor system. There is a need for a device that is capable of monitoring multiple physiological systems in various walking conditions. To address this need, an Android-based gait-monitoring device was developed that enabled the recording of a patient's physiological systems during walking. The gait-monitoring device was tested during self-regulated overground walking sessions of fifteen healthy subjects that included 6 females and 9 males aged 18-35 years. The gait-monitoring device measures the patient's stride interval, acceleration, electrocardiogram, skin conductance and respiratory rate. The data is stored on an Android phone and is analyzed offline through the extraction of features in the time, frequency and time-frequency domains. The analysis of the data depicted multisystem physiological interactions during overground walking in healthy subjects. These interactions included locomotion-electrodermal, locomotion-respiratory and cardiolocomotion couplings. The current results depicting strong interactions between the locomotion system and the other considered systems (i.e., electrodermal, respiratory and cardiovascular systems) warrant further investigation into multisystem interactions during walking, particularly in challenging walking conditions with older adults.

  10. The MsrA knockout mouse exhibits abnormal behavior and brain dopamine levels

    PubMed Central

    Oien, Derek B.; Osterhaus, Greg L.; Latif, Shaheen A.; Pinkston, Jonathan W.; Fulks, Jenny; Johnson, Michael; Fowler, Stephen C.; Moskovitz, Jackob

    2008-01-01

    Oxidative stress can cause methionine oxidation that has been implicated in various proteins malfunctions, if not adequately reduced by the methionine sulfoxide reductase system. Recent evidence has found oxidized methionine residues in neurodegenerative conditions. Previously, we have described elevated levels of brain pathologies and an abnormal walking pattern in the methionine sulfoxide reductase A knockout (MsrA−/−) mouse. Here we show that MsrA−/− mice have compromised complex task learning capabilities relative to wild-type mice. Likewise, MsrA−/− mice exhibit lower locomotor activity and altered gait that exacerbated with age. Furthermore, MsrA−/− mice were less responsive to amphetamine treatment. Consequently, brain dopamine levels were determined. Surprisingly, relative to wild-type mice, MsrA−/− brains contained significantly higher levels of dopamine up to 12 months of age, while lower level of dopamine was observed at 16 months of age. Moreover, striatal regions of MsrA−/− mice showed an increase of dopamine release parallel to observed dopamine levels. Similarly, the expression pattern of tyrosine hydroxylase activating protein correlated with the age-dependent dopamine levels. Thus, it is suggested that dopamine regulation and signaling pathway are impaired in MsrA−/− mice, which may contribute to their abnormal bio-behavior. These observations may be relevant to age-related neurological diseases associated with oxidative stress. PMID:18466776

  11. MsrA knockout mouse exhibits abnormal behavior and brain dopamine levels.

    PubMed

    Oien, Derek B; Osterhaus, Greg L; Latif, Shaheen A; Pinkston, Jonathan W; Fulks, Jenny; Johnson, Michael; Fowler, Stephen C; Moskovitz, Jackob

    2008-07-15

    Oxidative stress can cause methionine oxidation that has been implicated in various proteins malfunctions, if not adequately reduced by the methionine sulfoxide reductase system. Recent evidence has found oxidized methionine residues in neurodegenerative conditions. Previously, we have described elevated levels of brain pathologies and an abnormal walking pattern in the methionine sulfoxide reductase A knockout (MsrA(-/-)) mouse. Here we show that MsrA(-/-) mice have compromised complex task learning capabilities relative to wild-type mice. Likewise, MsrA(-/-) mice exhibit lower locomotor activity and altered gait that exacerbated with age. Furthermore, MsrA(-/-) mice were less responsive to amphetamine treatment. Consequently, brain dopamine levels were determined. Surprisingly, relative to wild-type mice, MsrA(-/-) brains contained significantly higher levels of dopamine up to 12 months of age, while lower levels of dopamine were observed at 16 months of age. Moreover, striatal regions of MsrA(-/-) mice showed an increase of dopamine release parallel to observed dopamine levels. Similarly, the expression pattern of tyrosine hydroxylase activating protein correlated with the age-dependent dopamine levels. Thus, it is suggested that dopamine regulation and signaling pathways are impaired in MsrA(-/-) mice, which may contribute to their abnormal behavior. These observations may be relevant to age-related neurological diseases associated with oxidative stress.

  12. Method to classify elderly subjects as fallers and non-fallers based on gait energy image.

    PubMed

    Gandomkar, Ziba; Bahrami, Fariba

    2014-09-01

    Falls are one of the leading causes of injuries among the elderly. Therefore, distinguishing fallers and performing preventive actions is vitally important. A new variation of the gait energy image (GEI) called coloured gait energy image (CGEI) is proposed for classifying subjects as fallers and non-fallers and for visualising their gait patterns. Eight elderly fallers, eight elderly non-fallers and eight young subjects performed timed up and go (TUG) test, which is one of the well-known clinical tools for fall risk assessment and contains two gait sequences. Subjects were also asked to perform two other variations of the TUG test, namely TUG with manual load and TUG with cognitive load. Gait sequences were extracted from the TUG test based on the opinion of three human observers. Then the gait cycles were automatically extracted from the walking sequence and divided into three phases, corresponding to double support and first and second half of single support. Next, the GEI of each phase was generated and formed one of the colour components of CGEI. Histogram-based features obtained from CGEI were then used to classify the video collected from walking sequences of elderly fallers and non-fallers. Correct classification rate was improved by approximately 27% compared with the standard TUG test.

  13. Estimation of muscle forces in gait using a simulation of the electromyographic activity and numerical optimization.

    PubMed

    Ravera, Emiliano Pablo; Crespo, Marcos José; Braidot, Ariel Andrés Antonio

    2016-01-01

    Clinical gait analysis provides great contributions to the understanding of gait patterns. However, a complete distribution of muscle forces throughout the gait cycle is a current challenge for many researchers. Two techniques are often used to estimate muscle forces: inverse dynamics with static optimization and computer muscle control that uses forward dynamics to minimize tracking. The first method often involves limitations due to changing muscle dynamics and possible signal artefacts that depend on day-to-day variation in the position of electromyographic (EMG) electrodes. Nevertheless, in clinical gait analysis, the method of inverse dynamics is a fundamental and commonly used computational procedure to calculate the force and torque reactions at various body joints. Our aim was to develop a generic musculoskeletal model that could be able to be applied in the clinical setting. The musculoskeletal model of the lower limb presents a simulation for the EMG data to address the common limitations of these techniques. This model presents a new point of view from the inverse dynamics used on clinical gait analysis, including the EMG information, and shows a similar performance to another model available in the OpenSim software. The main problem of these methods to achieve a correct muscle coordination is the lack of complete EMG data for all muscles modelled. We present a technique that simulates the EMG activity and presents a good correlation with the muscle forces throughout the gait cycle. Also, this method showed great similarities whit the real EMG data recorded from the subjects doing the same movement.

  14. Method to classify elderly subjects as fallers and non-fallers based on gait energy image.

    PubMed

    Gandomkar, Ziba; Bahrami, Fariba

    2014-09-01

    Falls are one of the leading causes of injuries among the elderly. Therefore, distinguishing fallers and performing preventive actions is vitally important. A new variation of the gait energy image (GEI) called coloured gait energy image (CGEI) is proposed for classifying subjects as fallers and non-fallers and for visualising their gait patterns. Eight elderly fallers, eight elderly non-fallers and eight young subjects performed timed up and go (TUG) test, which is one of the well-known clinical tools for fall risk assessment and contains two gait sequences. Subjects were also asked to perform two other variations of the TUG test, namely TUG with manual load and TUG with cognitive load. Gait sequences were extracted from the TUG test based on the opinion of three human observers. Then the gait cycles were automatically extracted from the walking sequence and divided into three phases, corresponding to double support and first and second half of single support. Next, the GEI of each phase was generated and formed one of the colour components of CGEI. Histogram-based features obtained from CGEI were then used to classify the video collected from walking sequences of elderly fallers and non-fallers. Correct classification rate was improved by approximately 27% compared with the standard TUG test. PMID:26609388

  15. Energy evaluation of a bio-inspired gait modulation method for quadrupedal locomotion.

    PubMed

    Fukuoka, Yasuhiro; Fukino, Kota; Habu, Yasushi; Mori, Yoshikazu

    2015-08-01

    We have proposed a bio-inspired gait modulation method, by means of which a simulated quadruped model can successfully perform smooth, autonomous gait transitions from a walk to a trot to a gallop, as observed in animals. The model is equipped with a rhythm generator called a central pattern generator (CPG) for each leg. The lateral neighbouring CPGs are mutually and inhibitorily coupled, and the CPG network is hardwired to produce a trot. Adding only the simple feedback of body tilt to each CPG, which was based on input from the postural reflex, led to the emergence of un-programmed walking and galloping at low and high speeds, respectively. Although this autonomous gait transition was a consequence of postural adaptation, it coincidentally also resulted in the minimization of energy consumption, as observed in real animals. In simulations at a variety of constant speeds the energy cost was lower for walking at low speeds and for galloping at high speeds than it was for trotting. Moreover, each gait transition occurred at the optimal speed, such that the model minimised its energy consumption. Thus, gait transitions in simulations that included the bio-inspired gait modulation method were similar to those observed in animals, even from the perspective of energy consumption. This method should therefore be a preferred choice for motion generation and control in biomimetic quadrupedal locomotion. PMID:26241690

  16. Markerless identification of key events in gait cycle using image flow.

    PubMed

    Vishnoi, Nalini; Duric, Zoran; Gerber, Naomi Lynn

    2012-01-01

    Gait analysis has been an interesting area of research for several decades. In this paper, we propose image-flow-based methods to compute the motion and velocities of different body segments automatically, using a single inexpensive video camera. We then identify and extract different events of the gait cycle (double-support, mid-swing, toe-off and heel-strike) from video images. Experiments were conducted in which four walking subjects were captured from the sagittal plane. Automatic segmentation was performed to isolate the moving body from the background. The head excursion and the shank motion were then computed to identify the key frames corresponding to different events in the gait cycle. Our approach does not require calibrated cameras or special markers to capture movement. We have also compared our method with the Optotrak 3D motion capture system and found our results in good agreement with the Optotrak results. The development of our method has potential use in the markerless and unencumbered video capture of human locomotion. Monitoring gait in homes and communities provides a useful application for the aged and the disabled. Our method could potentially be used as an assessment tool to determine gait symmetry or to establish the normal gait pattern of an individual.

  17. Single-trial classification of gait and point movement preparation from human EEG

    PubMed Central

    Velu, Priya D.; de Sa, Virginia R.

    2013-01-01

    Neuroimaging studies provide evidence of cortical involvement immediately before and during gait and during gait-related behaviors such as stepping in place or motor imagery of gait. Here we attempt to perform single-trial classification of gait intent from another movement plan (point intent) or from standing in place. Subjects walked naturally from a starting position to a designated ending position, pointed at a designated position from the starting position, or remained standing at the starting position. The 700 ms of recorded electroencephalography (EEG) before movement onset was used for single-trial classification of trials based on action type and direction (left walk, forward walk, right walk, left point, right point, and stand) as well as action type regardless of direction (stand, walk, point). Classification using regularized LDA was performed on a principal components analysis (PCA) reduced feature space composed of coefficients from levels 1 to 9 of a discrete wavelet decomposition using the Daubechies 4 wavelet. We achieved significant classification for all conditions, with errors as low as 17% when averaged across nine subjects. LDA and PCA highly weighted frequency ranges that included movement related potentials (MRPs), with smaller contributions from frequency ranges that included mu and beta idle motor rhythms. Additionally, error patterns suggested a spatial structure to the EEG signal. Future applications of the cortical gait intent signal may include an additional dimension of control for prosthetics, preemptive corrective feedback for gait disturbances, or human computer interfaces (HCI). PMID:23781166

  18. Gait characteristics of individuals with multiple sclerosis before and after a 6-month aerobic training program.

    PubMed

    Rodgers, M M; Mulcare, J A; King, D L; Mathews, T; Gupta, S C; Glaser, R M

    1999-07-01

    Individuals who have multiple sclerosis (MS) typically experience problems with physical activities such as walking, resulting from the combined effects of skeletal muscle weakness, sensory disturbances, spasticity, gait ataxia, and reduction in aerobic capacity. The aim of this study was to determine whether a 6-mo exercise program designed for aerobic conditioning might also affect gait abnormalities in individuals with MS. Subjects included 18 individuals with MS who presented a range of disability. Passive range of motion (PROM) in the lower limbs was measured and gait analyzed before and after exercise conditioning. Three-dimensional kinematics, ground reaction forces (GRF), and electromyographic information were acquired as subjects walked at self-selected velocities. Hip PROM increased following conditioning. Mean walking velocity, cadence, and posterior shear GRF (push-off force) decreased. During walking, maximum ankle dorsiflexion decreased and ankle plantarflexion increased. Total knee flexion/extension range during the walking cycle decreased slightly as did maximum hip extension. Results suggest this 6-mo training program had minimal effect on gait abnormalities. PMID:10659801

  19. Effects of robotic gait rehabilitation on biomechanical parameters in the chronic hemiplegic patients.

    PubMed

    Wallard, L; Dietrich, G; Kerlirzin, Y; Bredin, J

    2015-09-01

    Hemiplegia is a more or less complete loss of hemibody voluntary motricity following a brain injury, usually resulting in alterations of the locomotor system with persistent disorders of movement and posture. We were interested in studying the gait pattern called "stiff knee gait" with the main objective to highlight the role of a robotic rehabilitation in improving or modifying/changing the walking pattern in adults with chronic hemiplegic disorders. Data were collected by a motion analysis system (Vicon(®)--Oxford Metrics, Oxford, UK) in order to achieve a Clinical Gait Analysis before and after a robotic gait rehabilitation (Lokomat(®)). Four intensive sessions per weeks during five weeks were performed by ten chronic hemiplegic adults. The results show a significant improvement in locomotor parameters (walking speed, step length, single and double support time) and in the knee kinematics. This first study provides experimental evidence of the importance and usefulness of the robotic rehabilitation as an aid in the rehabilitation of gait pattern in adults with chronic hemiplegia.

  20. Application of the Gillette Gait Index, Gait Deviation Index and Gait Profile Score to multiple clinical pediatric populations.

    PubMed

    McMulkin, Mark L; MacWilliams, Bruce A

    2015-02-01

    Gait indices are now commonly used to assess overall pathology and outcomes from studies with instrumented gait analyses. There are differences in how these indices are calculated and therefore inherent differences in their sensitivities to detect changes or differences between groups. The purpose of the current study was to examine the three most commonly used gait indices, Gillette Gait Index (GGI), Gait Deviation Index (GDI), and Gait Profile Score (GPS), comparing the statistical sensitivity and the ability to make meaningful interpretations of the clinical results. In addition, the GDI*, a log transformed and scaled version of the GPS score which closely matches the GDI was examined. For seven previous or ongoing studies representing varying gait pathologies seen in clinical laboratories, the GGI, GDI, and GPS/GDI* were calculated retrospectively. The GDI and GPS/GDI* proved to be the most sensitive measures in assessing differences pre/post-treatment or from a control population. A power analysis revealed the GDI and GDI* to be the most sensitive statistical measures (lowest sample sizes required). Subjectively, the GDI and GDI* interpretation seemed to be the most intuitive measure for assessing clinical changes. However, the gait variable sub-scores of the GPS determined several statistical differences which were not previously noted and was the only index tool for quantifying the relative contributions of specific joints or planes of motion. The GGI did not offer any advantages over the other two indices.

  1. Regional neuromuscular regulation within human rectus femoris muscle during gait in young and elderly men.

    PubMed

    Watanabe, Kohei; Kouzaki, Motoki; Moritani, Toshio

    2016-01-01

    Recently, we demonstrated region-specific electromyography (EMG) responses along the rectus femoris (RF) muscle during gait in healthy young men (Watanabe et al., 2014b). For the RF muscle, regional EMG response should be tested to characterize neuromuscular control and/or to assess its dysfunction and/or pathology during gait. We aimed to identify spatial distribution of EMG pattern within the RF muscle in elderly during gait. Seven young men (age: 20.4±1.0 years) and 8 elderly men (age: 73.8±5.9 years) walked on treadmill with three different speed: slow (preferred -1km/h), preferred, and fast (preferred +1km/h). The spatial distribution of surface EMG was tested by central locus activation (CLA), which is calculated from 18 surface electrodes along the longitudinal line of the muscle. CLA were not different between the groups for slow and preferred gait speed (p>0.05) during a gait cycle. In fast gait speed, CLA at 80% of a gait cycle (swing phase) for the elderly were significantly located at more distal site than the young group (p<0.05) (13.0±2.1cm and 10.2±2.2cm from most proximal electrodes for the elderly and young). This difference in CLA reflected a significantly lower EMG activity at the proximal regions in the elderly group (p<0.05). These results suggest the elderly manifest characteristic regional EMG responses within the RF muscle for leg swing movement of fast speed gait.

  2. The Combined Effects of Body Weight Support and Gait Speed on Gait Related Muscle Activity: A Comparison between Walking in the Lokomat Exoskeleton and Regular Treadmill Walking

    PubMed Central

    Van Kammen, Klaske; Boonstra, Annemarijke; Reinders-Messelink, Heleen; den Otter, Rob

    2014-01-01

    Background For the development of specialized training protocols for robot assisted gait training, it is important to understand how the use of exoskeletons alters locomotor task demands, and how the nature and magnitude of these changes depend on training parameters. Therefore, the present study assessed the combined effects of gait speed and body weight support (BWS) on muscle activity, and compared these between treadmill walking and walking in the Lokomat exoskeleton. Methods Ten healthy participants walked on a treadmill and in the Lokomat, with varying levels of BWS (0% and 50% of the participants’ body weight) and gait speed (0.8, 1.8, and 2.8 km/h), while temporal step characteristics and muscle activity from Erector Spinae, Gluteus Medius, Vastus Lateralis, Biceps Femoris, Gastrocnemius Medialis, and Tibialis Anterior muscles were recorded. Results The temporal structure of the stepping pattern was altered when participants walked in the Lokomat or when BWS was provided (i.e. the relative duration of the double support phase was reduced, and the single support phase prolonged), but these differences normalized as gait speed increased. Alternations in muscle activity were characterized by complex interactions between walking conditions and training parameters: Differences between treadmill walking and walking in the exoskeleton were most prominent at low gait speeds, and speed effects were attenuated when BWS was provided. Conclusion Walking in the Lokomat exoskeleton without movement guidance alters the temporal step regulation and the neuromuscular control of walking, although the nature and magnitude of these effects depend on complex interactions with gait speed and BWS. If normative neuromuscular control of gait is targeted during training, it is recommended that very low speeds and high levels of BWS should be avoided when possible. PMID:25226302

  3. Comparison of Upright Gait with Supine Bungee-Cord Gait

    NASA Technical Reports Server (NTRS)

    Boda, Wanda L.; Hargens, Alan R.; Campbell, J. A.; Yang, C.; Holton, Emily M. (Technical Monitor)

    1998-01-01

    Running on a treadmill with bungee-cord resistance is currently used on the Russian space station MIR as a countermeasure for the loss of bone and muscular strength which occurs during spaceflight. However, it is unknown whether ground reaction force (GRF) at the feet using bungee-cord resistance is similar to that which occurs during upright walking and running on Earth. We hypothesized-that the DRAMs generated during upright walking and running are greater than the DRAMs generated during supine bungee-cord gait. Eleven healthy subjects walked (4.8 +/- 0.13 km/h, mean +/- SE) and ran (9.1 +/- 0.51 km/h) during upright and supine bungee-cord exercise on an active treadmill. Subjects exercised for 3 min in each condition using a resistance of 1 body weight calibrated during an initial, stationary standing position. Data were sampled at a frequency of 500Hz and the mean of 3 trials was analyzed for each condition. A repeated measures analysis of variance tested significance between the conditions. Peak DRAMs during upright walking were significantly greater (1084.9 +/- 111.4 N) than during supine bungee-cord walking (770.3 +/- 59.8 N; p less than 0.05). Peak GRFs were also significantly greater for upright running (1548.3 +/- 135.4 N) than for supine bungee-cord running (1099.5 +/- 158.46 N). Analysis of GRF curves indicated that forces decreased throughout the stance phase for bungee-cord gait but not during upright gait. These results indicate that bungee-cord exercise may not create sufficient loads at the feet to counteract the loss of bone and muscular strength that occurs during long-duration exposure to microgravity.

  4. pGALS – paediatric Gait Arms Legs and Spine: a simple examination of the musculoskeletal system

    PubMed Central

    2013-01-01

    We describe pGALS (paediatric Gait, Arms, Legs and Spine) – a simple quick musculoskeletal assessment to distinguish abnormal from normal joints in children and young people. The use of pGALS is aimed at the non-specialist in paediatric musculoskeletal medicine as a basic clinical skill to be used in conjunction with essential knowledge about red flags, normal development and awareness of patterns of musculoskeletal pathologies. pGALS has been validated in school-aged children and also in the context of acute general paediatrics to detect abnormal joints. We propose that pGALS is an important part of basic clinical skills to be acquired by all doctors who may be involved in the care of children. The learning of pGALS along with basic knowledge is a useful way to increase awareness of joint disease, facilitate early recognition of joint problems and prompt referral to specialist teams to optimise clinical outcomes. We have compiled this article as a resource that can be used by the paediatric rheumatology community to facilitate teaching. PMID:24219838

  5. A gait index may underestimate changes of gait: a comparison of the Movement Deviation Profile and the Gait Deviation Index.

    PubMed

    Barton, Gabor J; Hawken, Malcolm B; Holmes, Gill; Schwartz, Michael H

    2015-01-01

    The ability of the Movement Deviation Profile (MDP) and Gait Deviation Index (GDI) to detect gait changes was compared in a child with cerebral palsy who underwent game training. Conventional gait analysis showed that sagittal plane angles became mirrored about normality after training. Despite considerable gait changes, the GDI showed minimal change, while the MDP detected a difference equal to a shift between 10-9 on the Functional Assessment Questionnaire scale. Responses of the GDI and MDP were examined during a synthetic transition of the patient's curves from before intervention to a state mirrored about normality. The GDI showed a symmetric response on the two opposite sides of normality but the neural network based MDP gave an asymmetric response reflecting faithfully the unequal biomechanical consequences of joint angle changes. In conclusion, the MDP can detect altered gait even if the changes are missed by the GDI. PMID:23521124

  6. A gait index may underestimate changes of gait: a comparison of the Movement Deviation Profile and the Gait Deviation Index.

    PubMed

    Barton, Gabor J; Hawken, Malcolm B; Holmes, Gill; Schwartz, Michael H

    2015-01-01

    The ability of the Movement Deviation Profile (MDP) and Gait Deviation Index (GDI) to detect gait changes was compared in a child with cerebral palsy who underwent game training. Conventional gait analysis showed that sagittal plane angles became mirrored about normality after training. Despite considerable gait changes, the GDI showed minimal change, while the MDP detected a difference equal to a shift between 10-9 on the Functional Assessment Questionnaire scale. Responses of the GDI and MDP were examined during a synthetic transition of the patient's curves from before intervention to a state mirrored about normality. The GDI showed a symmetric response on the two opposite sides of normality but the neural network based MDP gave an asymmetric response reflecting faithfully the unequal biomechanical consequences of joint angle changes. In conclusion, the MDP can detect altered gait even if the changes are missed by the GDI.

  7. Variability and similarity of gait as evaluated by joint angles: implications for forensic gait analysis.

    PubMed

    Yang, Sylvia X M; Larsen, Peter K; Alkjær, Tine; Simonsen, Erik B; Lynnerup, Niels

    2014-03-01

    Closed-circuit television (CCTV) footage is used in criminal investigations to compare perpetrators with suspects. Usually, incomplete gait cycles are collected, making evidential gait analysis challenging. This study aimed to analyze the discriminatory power of joint angles throughout a gait cycle. Six sets from 12 men were collected. For each man, a variability range VR (mean ± 1SD) of a specific joint angle at a specific time point (a gait cycle was 100 time points) was calculated. In turn, each individual was compared with the 11 others, and whenever 1 of these 11 had a value within this individual’s VR, it counted as positive. By adding the positives throughout the gait cycle, we created simple bar graphs; tall bars indicated a small discriminatory power, short bars indicated a larger one. The highest discriminatory power was at time points 60–80 in the gait cycle. We show how our data can assess gait data from an actual case.

  8. Dependence of Gait Deviation on Weight-Bearing Asymmetry and Postural Instability in Children with Unilateral Cerebral Palsy

    PubMed Central

    Domagalska-Szopa, Małgorzata; Szopa, Andrzej; Czamara, Andrzej

    2016-01-01

    Postural control deficits have been suggested to be a major component of gait disorders in children with cerebral palsy. The purpose of this study was to investigate the relationship between postural stability and treadmill walking, in children with unilateral cerebral palsy, by defining dependence between the posturographic weight-bearing distribution and center of pressure (CoP) sway during quiet standing with Gillette Gait Index and the 16 distinct gait parameters that composed the Gillette Gait Index. Forty-five children with unilateral cerebral palsy from 7–12 years of age were included in this study. A posturographic procedure and 3-dimensional instrumented gait analysis was developed. In general, across the entire tested group, the significant correlations concerned only the asymmetry of the weight bearing and a few of the distinct gait parameters that compose the Gillette Gait Index; moreover, correlation coefficients were low. The division of subjects into two clinical subgroups: children that exhibited a tendency to overload (1) and to underload (2) the affected body side, modified the results of the explored relationships. Our findings revealed that the difficulties experienced by children with hemiplegia while controlled in a standing position result from tendency to excessively or insufficiently load the affected lower limbs, and thus establishes a direct relationship with inadequate affected peak ankle DF in both stance and swing gait phases. Given the presented relationship between postural instability and deviation of the particular gait parameters in children with unilateral cerebral palsy, a follow-up study will be needed to determine the therapeutic approaches that will be most effective in promoting increased improvement in gait pattern, as well as the static and dynamic balance in standing. PMID:27788247

  9. Feasibility study of a wearable exoskeleton for children: is the gait altered by adding masses on lower limbs?

    PubMed

    Rossi, Stefano; Colazza, Alessandra; Petrarca, Maurizio; Castelli, Enrico; Cappa, Paolo; Krebs, Hermano Igo

    2013-01-01

    We are designing a pediatric exoskeletal ankle robot (pediatric Anklebot) to promote gait habilitation in children with Cerebral Palsy (CP). Few studies have evaluated how much or whether the unilateral loading of a wearable exoskeleton may have the unwanted effect of altering significantly the gait. The purpose of this study was to evaluate whether adding masses up to 2.5 kg, the estimated overall added mass of the mentioned device, at the knee level alters the gait kinematics. Ten healthy children and eight children with CP, with light or mild gait impairment, walked wearing a knee brace with several masses. Gait parameters and lower-limb joint kinematics were analyzed with an optoelectronic system under six conditions: without brace (natural gait) and with masses placed at the knee level (0.5, 1.0, 1.5, 2.0, 2.5 kg). T-tests and repeated measures ANOVA tests were conducted in order to find noteworthy differences among the trial conditions and between loaded and unloaded legs. No statistically significant differences in gait parameters for both healthy children and children with CP were observed in the five "with added mass" conditions. We found significant differences among "natural gait" and "with added masses" conditions in knee flexion and hip extension angles for healthy children and in knee flexion angle for children with CP. This result can be interpreted as an effect of the mechanical constraint induced by the knee brace rather than the effect associated with load increase. The study demonstrates that the mechanical constraint induced by the brace has a measurable effect on the gait of healthy children and children with CP and that the added mass up to 2.5 kg does not alter the lower limb kinematics. This suggests that wearable devices weighing 25 N or less will not noticeably modify the gait patterns of the population examined here. PMID:24023822

  10. Feasibility study of a wearable exoskeleton for children: is the gait altered by adding masses on lower limbs?

    PubMed

    Rossi, Stefano; Colazza, Alessandra; Petrarca, Maurizio; Castelli, Enrico; Cappa, Paolo; Krebs, Hermano Igo

    2013-01-01

    We are designing a pediatric exoskeletal ankle robot (pediatric Anklebot) to promote gait habilitation in children with Cerebral Palsy (CP). Few studies have evaluated how much or whether the unilateral loading of a wearable exoskeleton may have the unwanted effect of altering significantly the gait. The purpose of this study was to evaluate whether adding masses up to 2.5 kg, the estimated overall added mass of the mentioned device, at the knee level alters the gait kinematics. Ten healthy children and eight children with CP, with light or mild gait impairment, walked wearing a knee brace with several masses. Gait parameters and lower-limb joint kinematics were analyzed with an optoelectronic system under six conditions: without brace (natural gait) and with masses placed at the knee level (0.5, 1.0, 1.5, 2.0, 2.5 kg). T-tests and repeated measures ANOVA tests were conducted in order to find noteworthy differences among the trial conditions and between loaded and unloaded legs. No statistically significant differences in gait parameters for both healthy children and children with CP were observed in the five "with added mass" conditions. We found significant differences among "natural gait" and "with added masses" conditions in knee flexion and hip extension angles for healthy children and in knee flexion angle for children with CP. This result can be interpreted as an effect of the mechanical constraint induced by the knee brace rather than the effect associated with load increase. The study demonstrates that the mechanical constraint induced by the brace has a measurable effect on the gait of healthy children and children with CP and that the added mass up to 2.5 kg does not alter the lower limb kinematics. This suggests that wearable devices weighing 25 N or less will not noticeably modify the gait patterns of the population examined here.

  11. Gait Analysis by High School Students

    ERIC Educational Resources Information Center

    Heck, Andre; van Dongen, Caroline

    2008-01-01

    Human walking is a complicated motion. Movement scientists have developed various research methods to study gait. This article describes how a high school student collected and analysed high quality gait data in much the same way that movement scientists do, via the recording and measurement of motions with a video analysis tool and via…

  12. Diabetic Foot Biomechanics and Gait Dysfunction

    PubMed Central

    Wrobel, James S.; Najafi, Bijan

    2010-01-01

    Background Diabetic foot complications represent significant morbidity and precede most of the lower extremity amputations performed. Peripheral neuropathy is a frequent complication of diabetes shown to affect gait. Glycosylation of soft tissues can also affect gait. The purpose of this review article is to highlight the changes in gait for persons with diabetes and highlight the effects of glycosylation on soft tissues at the foot–ground interface. Methods PubMed, the Cochrane Library, and EBSCOhost® on-line databases were searched for articles pertaining to diabetes and gait. Bibliographies from relevant manuscripts were also searched. Findings Patients with diabetes frequently exhibit a conservative gait strategy where there is slower walking speed, wider base of gait, and prolonged double support time. Glycosylation affects are observed in the lower extremities. Initially, skin thickness decreases and skin hardness increases; tendons thicken; muscles atrophy and exhibit activation delays; bones become less dense; joints have limited mobility; and fat pads are less thick, demonstrate fibrotic atrophy, migrate distally, and may be stiffer. Interpretation In conclusion, there do appear to be gait changes in patients with diabetes. These changes, coupled with local soft tissue changes from advanced glycosylated end products, also alter a patient’s gait, putting them at risk of foot ulceration. Better elucidation of these changes throughout the entire spectrum of diabetes disease can help design better treatments and potentially reduce the unnecessarily high prevalence of foot ulcers and amputation. PMID:20663446

  13. Differential Patterns of Abnormal Activity and Connectivity in the Amygdala-Prefrontal Circuitry in Bipolar-I and Bipolar-NOS Youth

    ERIC Educational Resources Information Center

    Ladouceur, Cecile D.; Farchione, Tiffany; Diwadkar, Vaibhav; Pruitt, Patrick; Radwan, Jacqueline; Axelson, David A.; Birmaher, Boris; Phillips, Mary L.

    2011-01-01

    Objective: The functioning of neural systems supporting emotion processing and regulation in youth with bipolar disorder not otherwise specified (BP-NOS) remains poorly understood. We sought to examine patterns of activity and connectivity in youth with BP-NOS relative to youth with bipolar disorder type I (BP-I) and healthy controls (HC). Method:…

  14. Average Gait Differential Image Based Human Recognition

    PubMed Central

    Chen, Jinyan; Liu, Jiansheng

    2014-01-01

    The difference between adjacent frames of human walking contains useful information for human gait identification. Based on the previous idea a silhouettes difference based human gait recognition method named as average gait differential image (AGDI) is proposed in this paper. The AGDI is generated by the accumulation of the silhouettes difference between adjacent frames. The advantage of this method lies in that as a feature image it can preserve both the kinetic and static information of walking. Comparing to gait energy image (GEI), AGDI is more fit to representation the variation of silhouettes during walking. Two-dimensional principal component analysis (2DPCA) is used to extract features from the AGDI. Experiments on CASIA dataset show that AGDI has better identification and verification performance than GEI. Comparing to PCA, 2DPCA is a more efficient and less memory storage consumption feature extraction method in gait based recognition. PMID:24895648

  15. Speed-dependent reference joint trajectory generation for robotic gait support.

    PubMed

    Koopman, B; van Asseldonk, E H F; van der Kooij, H

    2014-04-11

    For the control of actuated orthoses, or gait rehabilitation robotics, kinematic reference trajectories are often required. These trajectories, consisting of joint angles, angular velocities and accelerations, are highly dependent on walking-speed. We present and evaluate a novel method to reconstruct body-height and speed-dependent joint trajectories. First, we collected gait kinematics in fifteen healthy (middle) aged subjects (47-68), at a wide range of walking-speeds (0.5-5 kph). For each joint trajectory multiple key-events were selected (among which its extremes). Second, we derived regression-models that predict the timing, angle, angular velocity and acceleration for each key-event, based on walking-speed and the subject׳s body-height. Finally, quintic splines were fitted between the predicted key-events to reconstruct a full gait cycle. Regression-models were obtained for hip ab-/adduction, hip flexion/extension, knee flexion/extension and ankle plantar-/dorsiflexion. Results showed that the majority of the key-events were dependent on walking-speed, both in terms of timing and amplitude, whereas the body-height had less effect. The reconstructed trajectories matched the measured trajectories very well, in terms of angle, angular velocity and acceleration. For the angles the RMSE between the reconstructed and measured trajectories was 2.6°. The mean correlation coefficient between the reconstructed and measured angular trajectories was 0.91. The method and the data presented in this paper can be used to generate speed-dependent gait patterns. These patterns can be used for the control of several robotic gait applications. Alternatively they can assist the assessment of pathological gait, where they can serve as a reference for "normal" gait.

  16. Transitions between three swimming gaits in Paramecium escape

    PubMed Central

    Hamel, Amandine; Fisch, Cathy; Combettes, Laurent; Dupuis-Williams, Pascale; Baroud, Charles N.

    2011-01-01

    Paramecium and other protists are able to swim at velocities reaching several times their body size per second by beating their cilia in an organized fashion. The cilia beat in an asymmetric stroke, which breaks the time reversal symmetry of small scale flows. Here we show that Paramecium uses three different swimming gaits to escape from an aggression, applied in the form of a focused laser heating. For a weak aggression, normal swimming is sufficient and produces a steady swimming velocity. As the heating amplitude is increased, a higher acceleration and faster swimming are achieved through synchronized beating of the cilia, which begin by producing oscillating swimming velocities and later give way to the usual gait. Finally, escape from a life-threatening aggression is achieved by a “jumping” gait, which does not rely on the cilia but is achieved through the explosive release of a group of trichocysts in the direction of the hot spot. Measurements through high-speed video explain the role of trichocysts in defending against aggressions while showing unexpected transitions in the swimming of microorganisms. These measurements also demonstrate that Paramecium optimizes its escape pattern by taking advantage of its inertia. PMID:21464291

  17. Transitions between three swimming gaits in Paramecium escape.

    PubMed

    Hamel, Amandine; Fisch, Cathy; Combettes, Laurent; Dupuis-Williams, Pascale; Baroud, Charles N

    2011-05-01

    Paramecium and other protists are able to swim at velocities reaching several times their body size per second by beating their cilia in an organized fashion. The cilia beat in an asymmetric stroke, which breaks the time reversal symmetry of small scale flows. Here we show that Paramecium uses three different swimming gaits to escape from an aggression, applied in the form of a focused laser heating. For a weak aggression, normal swimming is sufficient and produces a steady swimming velocity. As the heating amplitude is increased, a higher acceleration and faster swimming are achieved through synchronized beating of the cilia, which begin by producing oscillating swimming velocities and later give way to the usual gait. Finally, escape from a life-threatening aggression is achieved by a "jumping" gait, which does not rely on the cilia but is achieved through the explosive release of a group of trichocysts in the direction of the hot spot. Measurements through high-speed video explain the role of trichocysts in defending against aggressions while showing unexpected transitions in the swimming of microorganisms. These measurements also demonstrate that Paramecium optimizes its escape pattern by taking advantage of its inertia.

  18. Reinforcement learning of periodical gaits in locomotion robots

    NASA Astrophysics Data System (ADS)

    Svinin, Mikhail; Yamada, Kazuyaki; Ushio, S.; Ueda, Kanji

    1999-08-01

    Emergence of stable gaits in locomotion robots is studied in this paper. A classifier system, implementing an instance- based reinforcement learning scheme, is used for sensory- motor control of an eight-legged mobile robot. Important feature of the classifier system is its ability to work with the continuous sensor space. The robot does not have a prior knowledge of the environment, its own internal model, and the goal coordinates. It is only assumed that the robot can acquire stable gaits by learning how to reach a light source. During the learning process the control system, is self-organized by reinforcement signals. Reaching the light source defines a global reward. Forward motion gets a local reward, while stepping back and falling down get a local punishment. Feasibility of the proposed self-organized system is tested under simulation and experiment. The control actions are specified at the leg level. It is shown that, as learning progresses, the number of the action rules in the classifier systems is stabilized to a certain level, corresponding to the acquired gait patterns.

  19. A non-human primate model of bipedal locomotion under restrained condition allowing gait studies and single unit brain recordings.

    PubMed

    Goetz, L; Piallat, B; Thibaudier, Y; Montigon, O; David, O; Chabardès, S

    2012-03-15

    For decades, several animal models of locomotion have allowed a better understanding of the basic physiological mechanisms of gait. However, unlike most of the mammals, the Order Primates is characterized by fundamental changes in locomotor behaviour. In particular, some primates use a specific pattern of locomotion and are able to naturally walk bipedally due possibly to a specific supra-spinal control of locomotion. These features must be taken into account when one considers to study the intrinsic properties of human gait. Thus, an experimental model of bipedal locomotion allowing precise and reproducible analysis of gait in non-human primate is still lacking. This study describes a non-human primate model of bipedal locomotion under restrained condition. We undertook a kinematic and biomechanic study in three Macaca fascicularis trained to walk bipedally on a treadmill. One of the primate was evaluated in complete head fixation. Gait visual analysis and electromyographic recordings provided pertinent description of the gait pattern. Step frequencies, step lengths, cycle and stance phase durations were correlated with Froude number (dimensionless velocity), whereas swing phase durations remained non-correlated. Gait patterns observed in our model were similar to those obtained in freely bipedal Macaca fuscata and to a lesser extend to Humans. Gait pattern was not modified by head fixation thereby allowing us to perform precise and repetitive micro electrode recordings of deep cerebral structures. Thus, the present model could provide a pertinent pre-clinical tool to study gait parameters and their neuronal control but also could be helpful to validate new therapeutics interventions. PMID:22155386

  20. Motion analysis of Chinese normal knees during gait based on a novel portable system.

    PubMed

    Zhang, Yu; Yao, Zilong; Wang, Shaobai; Huang, Wenhan; Ma, Limin; Huang, Huayang; Xia, Hong

    2015-03-01

    Normative tibiofemoral data of Chinese or Asian subjects during gait is rarely reported. This study is aimed at investigating the six-degree-of-freedom (6DOF) knee kinematics of adult Chinese during gait, based on a novel portable system. Twenty-eight healthy Chinese subjects (56 knees) were studied during their treadmill gaits. A set of optical marker clusters were attached to the thighs and shanks of each subject, who was tracked by an optical joint kinematics measurement system. Knee landmarks were initially digitized with respect to the marker cluster sets to determine the local coordinate systems for calculation of 6DOF knee joint kinematics. The range of motion (ROM) in 6DOF and 5 kinematic parameters were calculated and compared between bilateral knees and genders. We discovered that knee rotations, as well as motion in proximodistal and mediolateral translations, showed similar patterns in flexion and extension. However, the anteroposterior translations did not show a clear pattern. The results of ROM in 6DOF obtained in this study are comparable with those reported in existing literature. No statistical difference was found between left and right knees either in the ROMs or in the 5 kinematic parameters. However, the ROM in the mediolateral direction during gait was found to be higher in men than women (P=0.014). In addition, the femurs of female subjects rotated more internally than the femurs of male during the stance phase (P=0.011). We concluded that normal Chinese knees exhibited distinct gait patterns, except for anteroposterior motion. Women and men exhibit different axial rotations and mediolateral translation patterns during their treadmill gait.

  1. Crouch gait changes after planovalgus foot deformity correction in ambulatory children with cerebral palsy.

    PubMed

    Kadhim, Muayad; Miller, Freeman

    2014-02-01

    Ambulatory children with cerebral palsy (CP) may present with several gait patterns due to muscular spasticity, commonly with crouch gait. Several factors may contribute to continuous knee flexion during gait, including hamstring and gastrocnemius contracture. In planovalgus foot deformity, the combination of heel equinus, talonavicular joint dislocation, midfoot break and external tibial torsion also contribute to crouch gait as part of lever arm dysfunction. In this retrospective cohort study, we assessed 21 children with CP (34 feet) who underwent planovalgus foot correction as a single level surgery. Fifteen feet underwent subtalar fusion and 19 feet had lateral calcaneal lengthening. Patients who underwent knee, hip or pelvis surgeries were excluded from the study. The aim was to examine the changes in gait pattern and the correlation between the changes of knee flexion at stance phase with the other kinematic and kinetic parameters after foot surgery. Post surgery change of Maximum knee extension at stance (MKE-dif) was the outcome of interest. The magnitude of change in MKE after surgery increased (less crouch after surgery) in patients who had milder preoperative planovalgus feet and higher preoperative ankle maximum dorsiflexion at stance and ankle power. The gain of knee extension after surgery correlated with correction of ankle hyperdorsiflexion and with increase of knee extension at initial contact and knee power. Patients with high preoperative ankle maximum dorsiflexion may benefit from surgical foot deformity correction to achieve decreased ankle dorsiflexion with no knee surgical intervention.

  2. An ear-worn sensor for the detection of gait impairment after abdominal surgery.

    PubMed

    Atallah, Louis; Aziz, Omer; Gray, Edward; Lo, Benny; Yang, Guang-Zhong

    2013-02-01

    Surgery to the trunk often results in a change of gait, most pronounced during walking. This change is usually transient, often as a result of wound pain, and returns to normal as the patient recovers. Quantifying and monitoring gait impairment therefore represents a novel means of functional postoperative home recovery follow-up. Until now, this type of assessment could only be made in a gait lab, which is both expensive and labor intensive to administer on a large scale. The objective of this work is to validate the use of an ear-worn activity recognition (e-AR) sensor for quantification of gait impairment after abdominal wall and perianal surgery. The e-AR sensor was used on 2 comparative simulated data sets (N = 32) of truncal impairment to observe walking patterns. The sensor was also used to observe the walking patterns of preoperative and postoperative surgical patients who had undergone abdominal wall (n = 5) and perianal surgery (n = 5). Methods for multiresolution feature extraction, selection, and classification are investigated using the raw ear-sensor data. Results show that the method demonstrates a good separation between impaired and nonimpaired classes for both simulated and real patient data sets. This indicates that the e-AR sensor may be used as a tool for the pervasive assessment of postoperative gait impairment, as part of functional recovery monitoring, in patients at their own homes.

  3. Spatiotemporal variability during gait initiation in Parkinson's disease.

    PubMed

    Roemmich, Ryan T; Nocera, Joe R; Vallabhajosula, Srikant; Amano, Shinichi; Naugle, Kelly M; Stegemöller, Elizabeth L; Hass, Chris J

    2012-07-01

    During gait initiation (GI), consistency of foot placement while stepping is important in making successful transitions from a state of stable static posture to an unstable state of dynamic locomotion. In populations characterized by gait dysfunction and postural instability, such as persons with Parkinson's disease (PD), the ability to generate a consistent stepping pattern during GI may be essential in the prevention of falls. However, little is known about GI variability in persons with PD as compared to their healthy elderly peers. Therefore, this study investigated spatiotemporal variability during the first two steps of GI in 46 persons with idiopathic PD and 49 healthy age-matched adults. Stepping characteristics, including the length, width, and time of the first two steps of GI as well as their coefficients of variation (CV) were compared between groups. Persons with PD initiated gait with significantly shorter steps (swing step length=.463 vs. .537 m, stance step length=.970 vs. 1.10 m) and higher variability in step length (swing step CV=8.82 vs. 5.45, stance step CV=6.76 vs. 3.61). Persons with PD also showed significantly higher variability in the time of the swing step (swing step CV=10.0 vs. 7.4). GI variability did not differ significantly between disease stages in persons with PD. Because greater variability in these measures during gait is related to an increased risk of falls, we propose that higher GI variability may play a considerable role in falls frequently observed during transitions from quiet standing in PD.

  4. Spatiotemporal variability during gait initiation in Parkinson’s disease

    PubMed Central

    Roemmich, Ryan T.; Nocera, Joe R.; Vallabhajosula, Srikant; Amano, Shinichi; Naugle, Kelly M.; Stegemöller, Elizabeth L.; Hass, Chris J.

    2012-01-01

    During gait initiation (GI), consistency of foot placement while stepping is important in making successful transitions from a state of stable static posture to an unstable state of dynamic locomotion. In populations characterized by gait dysfunction and postural instability, such as persons with Parkinson’s disease (PD), the ability to generate a consistent stepping pattern during GI may be essential in the prevention of falls. However, little is known about GI variability in persons with PD as compared to their healthy elderly peers. Therefore, this study investigated spatiotemporal variability during the first two steps of GI in 46 persons with idiopathic PD and 49 healthy age-matched adults. Stepping characteristics, including the length, width, and time of the first two steps of GI as well as their coefficients of variation (CV) were compared between groups. Persons with PD initiated gait with significantly shorter steps (swing step length = .463 vs .537m, stance step length = .970 vs. 1.10m) and higher variability in step length (swing step CV = 8.82 vs. 5.45, stance step CV = 6.76 vs. 3.61). Persons with PD also showed significantly higher variability in the time of the swing step (swing step CV = 10.0 vs. 7.4). GI variability did not differ significantly between disease stages in persons with PD. Because greater variability in these measures during gait is related to an increased risk of falls, we propose that higher GI variability may play a considerable role in falls frequently observed during transitions from quiet standing in PD. PMID:22543093

  5. Effects of Physical Rehabilitation Integrated with Rhythmic Auditory Stimulation on Spatio-Temporal and Kinematic Parameters of Gait in Parkinson's Disease.

    PubMed

    Pau, Massimiliano; Corona, Federica; Pili, Roberta; Casula, Carlo; Sors, Fabrizio; Agostini, Tiziano; Cossu, Giovanni; Guicciardi, Marco; Murgia, Mauro

    2016-01-01

    Movement rehabilitation by means of physical therapy represents an essential tool in the management of gait disturbances induced by Parkinson's disease (PD). In this context, the use of rhythmic auditory stimulation (RAS) has been proven useful in improving several spatio-temporal parameters, but concerning its effect on gait patterns, scarce information is available from a kinematic viewpoint. In this study, we used three-dimensional gait analysis based on optoelectronic stereophotogrammetry to investigate the effects of 5 weeks of supervised rehabilitation, which included gait training integrated with RAS on 26 individuals affected by PD (age 70.4 ± 11.1, Hoehn and Yahr 1-3). Gait kinematics was assessed before and at the end of the rehabilitation period and after a 3-month follow-up, using concise measures (Gait Profile Score and Gait Variable Score, GPS and GVS, respectively), which are able to describe the deviation from a physiologic gait pattern. The results confirm the effectiveness of gait training assisted by RAS in increasing speed and stride length, in regularizing cadence and correctly reweighting swing/stance phase duration. Moreover, an overall improvement of gait quality was observed, as demonstrated by the significant reduction of the GPS value, which was created mainly through significant decreases in the GVS score associated with the hip flexion-extension movement. Future research should focus on investigating kinematic details to better understand the mechanisms underlying gait disturbances in people with PD and the effects of RAS, with the aim of finding new or improving current rehabilitative treatments. PMID:27563296

  6. Effects of Physical Rehabilitation Integrated with Rhythmic Auditory Stimulation on Spatio-Temporal and Kinematic Parameters of Gait in Parkinson’s Disease

    PubMed Central

    Pau, Massimiliano; Corona, Federica; Pili, Roberta; Casula, Carlo; Sors, Fabrizio; Agostini, Tiziano; Cossu, Giovanni; Guicciardi, Marco; Murgia, Mauro

    2016-01-01

    Movement rehabilitation by means of physical therapy represents an essential tool in the management of gait disturbances induced by Parkinson’s disease (PD). In this context, the use of rhythmic auditory stimulation (RAS) has been proven useful in improving several spatio-temporal parameters, but concerning its effect on gait patterns, scarce information is available from a kinematic viewpoint. In this study, we used three-dimensional gait analysis based on optoelectronic stereophotogrammetry to investigate the effects of 5 weeks of supervised rehabilitation, which included gait training integrated with RAS on 26 individuals affected by PD (age 70.4 ± 11.1, Hoehn and Yahr 1–3). Gait kinematics was assessed before and at the end of the rehabilitation period and after a 3-month follow-up, using concise measures (Gait Profile Score and Gait Variable Score, GPS and GVS, respectively), which are able to describe the deviation from a physiologic gait pattern. The results confirm the effectiveness of gait training assisted by RAS in increasing speed and stride length, in regularizing cadence and correctly reweighting swing/stance phase duration. Moreover, an overall improvement of gait quality was observed, as demonstrated by the significant reduction of the GPS value, which was created mainly through significant decreases in the GVS score associated with the hip flexion–extension movement. Future research should focus on investigating kinematic details to better understand the mechanisms underlying gait disturbances in people with PD and the effects of RAS, with the aim of finding new or improving current rehabilitative treatments. PMID:27563296

  7. Repeated stress-induced expression pattern alterations of the hippocampal chloride transporters KCC2 and NKCC1 associated with behavioral abnormalities in female mice.

    PubMed

    Tsukahara, Takao; Masuhara, Masaaki; Iwai, Haruki; Sonomura, Takahiro; Sato, Tomoaki

    2015-09-11

    The balance of cation-chloride co-transporters, particularly KCC2 and NKCC1, is critical for GABAergic inhibitory signaling. However, KCC2/NKCC1 balance is disrupted in many neurodegenerative diseases. Moreover, correlations between chronic stress, KCC2 and NKCC1 in the hippocampus remain poorly understood. Despite the fact that emotional disorders in humans are far more prevalent in women, there have been relatively few studies about female subjects. Here we investigated behaviors and expression patterns of KCC2 and NKCC1 in the hippocampi of female mice under chronic stress. Repeated stress (RS) was induced in experimental mice by repeated forced water administration. Then, expression patterns of GABAergic signaling molecules were identified by immunohistochemical analysis and performance was assessed using several behavioral tests. The results of semi-quantitative analysis showed that RS decreased KCC2 expression and increased NKCC1 expression in membranes of granular and pyramidal cells in the hippocampus. The novel object recognition (NOR) test and sociability test revealed that RS induced cognitive and sociability deficits, whereas RS increased the time spent in the open arms of the elevated plus maze test and induced attention deficits in other tests. In summary, RS induced alterations in membrane KCC2/NKCC1 balance in the hippocampus of female mice, which may contribute to GABAergic disinhibition associated with cognitional, sociability and attention deficits. PMID:26239662

  8. Development of an Inflight Countermeasure to Mitigate Postflight Gait Dysfunction

    NASA Technical Reports Server (NTRS)

    Bloomberg, J. J.; Mulavara, A. P.; Peters, B. T.; Cohen, H. S.; Richards, J. T.; Miller, C. A.; Brady, R.; Warren, L. E.

    2005-01-01

    Following spaceflight crewmembers experience gait and postural instabilities due to inflight adaptive alterations in sensorimotor function. These changes can pose a risk to crew safety if nominal or emergency vehicle egress is required immediately following long-duration spaceflight. At present, no operational countermeasure is available to mitigate postflight locomotor disturbances. Therefore, the goal of this study is to develop an inflight training regimen that facilitates the recovery of locomotor function after long-duration spaceflight. The countermeasure we are developing is based on the concept of variable practice. During this type of training the subject gains experience producing the appropriate adaptive motor behavior under a variety of sensory conditions and response constraints. This countermeasure is built around current ISS treadmill exercise activities. Crewmembers will conduct their nominal inflight treadmill exercise while being exposed to variations in visual flow patterns. These variations will challenge the postural and locomotor systems repeatedly, thereby promoting adaptive reorganization in locomotor behavior. As a result of this training a subject learns to solve a class of motor problems, rather than a specific motor solution to one problem, Le., the subject learns response generalizability or the ability to "learn to learn" under a variety of environmental constraints. We anticipate that this training will accelerate recovery of postural and locomotor function during readaptation to gravitational environments following spaceflight facilitating neural adaptation to unit (Earth) and partial (Mars) gravity after long-duration spaceflight. The study calls for one group of subjects to perform the inflight treadmill training regimen while a control group of subjects performs only the nominal exercise procedures. Locomotor function in both groups is assessed before and after spaceflight using two tests of gait function: The Integrated Treadmill

  9. DEVELOPMENT OF AN INFLIGHT COUNTERMEASURE TO MITIGATE POSTFLIGHT GAIT DYSFUNCTION

    NASA Technical Reports Server (NTRS)

    Bloomberg, J. J.; Mulavara, A. P.; Cohen, H. S.; Richards, J. T.; Miller, C. A.

    2005-01-01

    Following spaceflight crewmembers experience gait and postural instabilities due to inflight adaptive alterations in sensorimotor function. These changes can pose a risk to crew safety if nominal or emergency vehicle egress is required immediately following long-duration spaceflight. At present, no operational countermeasure is available to mitigate postflight locomotor disturbances. Therefore, the goal of this study is to develop an inflight training regimen that facilitates the recovery of locomotor function after long-duration spaceflight. The countermeasure we are developing is based on the concept of variable practice. During this type of training the subject gains experience producing the appropriate adaptive motor behavior under a variety of sensory conditions and response constraints. This countermeasure is built around current ISS treadmill exercise activities. Crewmembers will conduct their nominal inflight treadmill exercise while being exposed to variations in visual flow patterns. These variations will challenge the postural and locomotor systems repeatedly, thereby promoting adaptive reorganization in locomotor behavior. As a result of this training a subject learns to solve a class of motor problems, rather than a specific motor solution to one problem, Le., the subject learns response generalizability or the ability to "learn to learn" under a variety of environmental constraints. We anticipate that this training will accelerate recovery of postural and locomotor function during readaptation to gravitational environments following spaceflight facilitating neural adaptation to unit (Earth) and partial (Mars) gravity after long-duration spaceflight. The study calls for one group of subjects to perform the inflight treadmill training regimen while a control group of subjects performs only the nominal exercise procedures. Locomotor function in both groups is assessed before and after spaceflight using two tests of gait function: The Integrated Treadmill

  10. Gait parameters associated with balance in healthy 2- to 4-year-old children.

    PubMed

    Guffey, Keegan; Regier, Michael; Mancinelli, Corrie; Pergami, Paola

    2016-01-01

    The use of validated measurements of gait and balance are crucial to establish baseline function and assess effectiveness of therapeutic interventions. Gait in children changes with motor development requiring frequent observations to effectively track progress. Standardized baseline spatiotemporal measurements and a greater understanding of the relationship between gait and balance would provide important feedback to clinicians regarding the effectiveness of rehabilitation and guide treatment modifications. 84 subjects (2.0-4.9 years) walked along the GAITRite(®), a walkway that records spatiotemporal parameters. The Pediatric Balance Scale (PBS) was administered to assess balance. Comparison of spatiotemporal parameter means between age groups showed trends associated with motor development similar to the ones described in the literature such as decreased cadence and increased step/stride length with increasing age. However, no significant differences in normalized spatiotemporal parameters were found between age groups. Age, leg length, cadence, step/stride length, step/stance time, and single/double support time showed significant correlation with balance scores. When the parameters were grouped into spatial, temporal, and age-related components using principal components analysis and included in a multiple regression model, they significantly predicted 51% of the balance score variance. Age-related components most strongly predicted balance outcomes. We suggest that balance can potentially be evaluated by assessment of spatial, temporal, and age-related characteristics of gait such as step length, cadence, and leg length. This suggests the possibility of developing new gait measurement technology that could provide functional assessment and track improvements during rehabilitation regimens. If the same model can be applied to monitor treatment efficacy in children with gait abnormalities remains to be addressed.

  11. Gait variability and disability in multiple sclerosis.

    PubMed

    Socie, Michael J; Motl, Robert W; Pula, John H; Sandroff, Brian M; Sosnoff, Jacob J

    2013-05-01

    Gait variability is clinically relevant in some populations, but there is limited documentation of gait variability in persons with multiple sclerosis (MS). This investigation examined average and variability of spatiotemporal gait parameters in persons with MS and healthy controls and subsequent associations with disability status. 88 individuals with MS (age 52.4±11.1) and 20 healthy controls (age 50.9±8.7) performed two self-paced walking trials on a 7.9-m electronic walkway to determine gait parameters. Disability was indexed by the Expanded Disability Status Scale (EDSS) and ranged between 2.5 and 6.5. Gait variability was indexed by standard deviation (SD) and coefficient of variation (CV=SD/mean) of step time, step length, and step width. Average gait parameters were significantly correlated with EDSS (ρ=0.756-0.609) and were significantly different in individuals with MS compared to controls (p≤0.002). Also, step length (p<0.001) and step time (p<0.001) variability were both significantly greater in MS compared to controls. EDSS was positively correlated with step length variability and individuals with MS who used assistive devices to walk had significantly greater step length variability than those who walked independently (p's<.05). EDSS was correlated with step time and length variability even when age was taken into account. Additionally, Fisher's z test of partial correlations revealed that average gait parameters were more closely related to disability status than gait variability in individuals with MS. This suggests that focusing on average gait parameters may be more important than variability in therapeutic interventions in MS.

  12. Up-regulation of the mammalian target of rapamycin complex 1 subunit Raptor by aldosterone induces abnormal pulmonary artery smooth muscle cell survival patterns to promote pulmonary arterial hypertension.

    PubMed

    Aghamohammadzadeh, Reza; Zhang, Ying-Yi; Stephens, Thomas E; Arons, Elena; Zaman, Paula; Polach, Kevin J; Matar, Majed; Yung, Lai-Ming; Yu, Paul B; Bowman, Frederick P; Opotowsky, Alexander R; Waxman, Aaron B; Loscalzo, Joseph; Leopold, Jane A; Maron, Bradley A

    2016-07-01

    Activation of the mammalian target of rapamycin complex 1 (mTORC1) subunit Raptor induces cell growth and is a downstream target of Akt. Elevated levels of aldosterone activate Akt, and, in pulmonary arterial hypertension (PAH), correlate with pulmonary arteriole thickening, which suggests that mTORC1 regulation by aldosterone may mediate adverse pulmonary vascular remodeling. We hypothesized that aldosterone-Raptor signaling induces abnormal pulmonary artery smooth muscle cell (PASMC) survival patterns to promote PAH. Remodeled pulmonary arterioles from SU-5416/hypoxia-PAH rats and monocrotaline-PAH rats with hyperaldosteronism expressed increased levels of the Raptor target, p70S6K, which provided a basis for investigating aldosterone-Raptor signaling in human PASMCs. Aldosterone (10(-9) to 10(-7) M) increased Akt/mTOR/Raptor to activate p70S6K and increase proliferation, viability, and apoptosis resistance in PASMCs. In PASMCs transfected with Raptor-small interfering RNA or treated with spironolactone/eplerenone, aldosterone or pulmonary arterial plasma from patients with PAH failed to increase p70S6K activation or to induce cell survival in vitro Optimal inhibition of pulmonary arteriole Raptor was achieved by treatment with Staramine-monomethoxy polyethylene glycol that was formulated with Raptor-small interfering RNA plus spironolactone in vivo, which decreased arteriole muscularization and pulmonary hypertension in 2 experimental animal models of PAH in vivo Up-regulation of mTORC1 by aldosterone is a critical pathobiologic mechanism that controls PASMC survival to promote hypertrophic vascular remodeling and PAH.-Aghamohammadzadeh, R., Zhang, Y.-Y., Stephens, T. E., Arons, E., Zaman, P., Polach, K. J., Matar, M., Yung, L.-M., Yu, P. B., Bowman, F. P., Opotowsky, A. R., Waxman, A. B., Loscalzo, J., Leopold, J. A., Maron, B. A. Up-regulation of the mammalian target of rapamycin complex 1 subunit Raptor by aldosterone induces abnormal pulmonary artery smooth

  13. Variations in kinematics during clinical gait analysis in stroke patients.

    PubMed

    Boudarham, Julien; Roche, Nicolas; Pradon, Didier; Bonnyaud, Céline; Bensmail, Djamel; Zory, Raphael

    2013-01-01

    In addition to changes in spatio-temporal and kinematic parameters, patients with stroke exhibit fear of falling as well as fatigability during gait. These changes could compromise interpretation of data from gait analysis. The aim of this study was to determine if the gait of hemiplegic patients changes significantly over successive gait trials. Forty two stroke patients and twenty healthy subjects performed 9 gait trials during a gait analysis session. The mean and variability of spatio-temporal and kinematic joint parameters were analyzed during 3 groups of consecutive gait trials (1-3, 4-6 and 7-9). Principal component analysis was used to reduce the number of variables from the joint kinematic waveforms and to identify the parts of the gait cycle which changed during the gait analysis session. The results showed that i) spontaneous gait velocity and the other spatio-temporal parameters significantly increased, and ii) gait variability decreased, over the last 6 gait trials compared to the first 3, for hemiplegic patients but not healthy subjects. Principal component analysis revealed changes in the sagittal waveforms of the hip, knee and ankle for hemiplegic patients after the first 3 gait trials. These results suggest that at the beginning of the gait analysis session, stroke patients exhibited phase of adaptation,characterized by a "cautious gait" but no fatigue was observed.

  14. Gait adaptation in ACL deficient patients before and after anterior cruciate ligament reconstruction surgery.

    PubMed

    Knoll, Zsolt; Kiss, Rita M; Kocsis, László

    2004-06-01

    The objective of this study is to determine how kinematical parameters and electromyography data of selected muscles may change as a result of anterior cruciate ligament (ACL) deficiency and following ACL reconstruction. The study was conducted on 25 anterior cruciate ligament deficient subjects prior to and 6 weeks, 4 months, 8 months and 12 months following ACL reconstructive surgery using the bone-patellar tendon-bone technique. Gait analysis was performed by applying the zebris three-dimensional ultrasound-based system with surface electromyograph (zebris). Kinematic data were recorded for the lower limb. The muscles surveyed include vastus lateralis and medialis, biceps femoris and adductor longus. The results obtained from the injured subjects were compared with those of 51 individuals without any ACL damage whatsoever. Acute ACL deficient patients exhibited a quadriceps avoidance pattern prior to and 6 weeks following surgery. No quadriceps avoidance phenomenon develops in chronic ACL deficient patients. In operated individuals, tempo-spatial parameters and the knee angle regained a normal pattern for the ACL-deficient limb during gait as early as 4 months following surgery. However, the relative ACL movement parameter, which describes the tibial translation into the direction of ACL, and the EMG traces show no significant statistical difference compared with the same values of the healthy control group just 8 months following surgery. The analysis of spatial-temporal parameters and EMG traces show that the development of a quadriceps avoidance pattern is less common than previously reported. These data suggest that anterior cruciate ligament deficiency and reconstruction produce considerable changes in the lower extremity gait pattern. The results suggest that gait parameters tend to shift towards a normal value pattern; and the re-establishment of pre-injury gait patterns-including the normal biphase of muscles-takes at least 8 months to occur.

  15. How useful is satellite positioning system (GPS) to track gait parameters? A review

    PubMed Central

    Terrier, Philippe; Schutz, Yves

    2005-01-01

    Over the last century, numerous techniques have been developed to analyze the movement of humans while walking and running. The combined use of kinematics and kinetics methods, mainly based on high speed video analysis and forceplate, have permitted a comprehensive description of locomotion process in terms of energetics and biomechanics. While the different phases of a single gait cycle are well understood, there is an increasing interest to know how the neuro-motor system controls gait form stride to stride. Indeed, it was observed that neurodegenerative diseases and aging could impact gait stability and gait parameters steadiness. From both clinical and fundamental research perspectives, there is therefore a need to develop techniques to accurately track gait parameters stride-by-stride over a long period with minimal constraints to patients. In this context, high accuracy satellite positioning can provide an alternative tool to monitor outdoor walking. Indeed, the high-end GPS receivers provide centimeter accuracy positioning with 5–20 Hz sampling rate: this allows the stride-by-stride assessment of a number of basic gait parameters – such as walking speed, step length and step frequency – that can be tracked over several thousand consecutive strides in free-living conditions. Furthermore, long-range correlations and fractal-like pattern was observed in those time series. As compared to other classical methods, GPS seems a promising technology in the field of gait variability analysis. However, relative high complexity and expensiveness – combined with a usability which requires further improvement – remain obstacles to the full development of the GPS technology in human applications. PMID:16138922

  16. A computational framework to predict post-treatment outcome for gait-related disorders.

    PubMed

    Reinbolt, Jeffrey A; Haftka, Raphael T; Chmielewski, Terese L; Fregly, Benjamin J

    2008-05-01

    Clinicians often use intuitive models based on clinical experience or regression models based on population studies to plan treatment of gait-related disorders. Because such models are constructed using data collected from previous patients, the predicted clinical outcome for a particular patient may not be reliable. We propose a new approach that uses computational models based on engineering mechanics to predict post-treatment outcome from pre-treatment movement data. The approach utilizes a four-phase optimization process built around a dynamic, patient-specific gait model. The first three phases calibrate the model's joint, inertial, and control parameters, respectively, where the control parameters are weights in an optimization cost function that tracks the patient's pre-treatment gait motion and loads. The last phase predicts the patient's post-treatment gait pattern by performing a tracking optimization with the calibrated model modified to simulate the selected treatment. We demonstrate the approach by simulating how two treatments for knee osteoarthritis (OA)--gait modification and high tibial osteotomy (HTO) surgery--alter the external knee adduction torque for a specific patient. By performing multiple tracking optimizations, we calibrated the model's parameter values to reproduce the patient's knee adduction torque curve for a toe out gait motion. When we performed a tracking optimization with the calibrated model using a modified footpath to simulate an increased stance width, the predicted reduction in both adduction torque peaks matched experimental results to within 4.8% error. When we performed a tracking optimization with the same model using modified leg geometry to simulate HTO surgery, the predicted reductions were consistent with published data. The approach requires further evaluation with a larger number of patients to determine its effectiveness for planning the treatment of gait-related disorders on a patient-specific basis.

  17. How useful is satellite positioning system (GPS) to track gait parameters? A review.

    PubMed

    Terrier, Philippe; Schutz, Yves

    2005-09-02

    Over the last century, numerous techniques have been developed to analyze the movement of humans while walking and running. The combined use of kinematics and kinetics methods, mainly based on high speed video analysis and forceplate, have permitted a comprehensive description of locomotion process in terms of energetics and biomechanics. While the different phases of a single gait cycle are well understood, there is an increasing interest to know how the neuro-motor system controls gait form stride to stride. Indeed, it was observed that neurodegenerative diseases and aging could impact gait stability and gait parameters steadiness. From both clinical and fundamental research perspectives, there is therefore a need to develop techniques to accurately track gait parameters stride-by-stride over a long period with minimal constraints to patients. In this context, high accuracy satellite positioning can provide an alternative tool to monitor outdoor walking. Indeed, the high-end GPS receivers provide centimeter accuracy positioning with 5-20 Hz sampling rate: this allows the stride-by-stride assessment of a number of basic gait parameters--such as walking speed, step length and step frequency--that can be tracked over several thousand consecutive strides in free-living conditions. Furthermore, long-range correlations and fractal-like pattern was observed in those time series. As compared to other classical methods, GPS seems a promising technology in the field of gait variability analysis. However, relative high complexity and expensiveness--combined with a usability which requires further improvement--remain obstacles to the full development of the GPS technology in human applications.

  18. Lower limb antagonist muscle co-activation and its relationship with gait parameters in cerebellar ataxia.

    PubMed

    Mari, Silvia; Serrao, Mariano; Casali, Carlo; Conte, Carmela; Martino, Giovanni; Ranavolo, Alberto; Coppola, Gianluca; Draicchio, Francesco; Padua, Luca; Sandrini, Giorgio; Pierelli, Francesco

    2014-04-01

    Increased antagonist muscle co-activation, seen in motor-impaired individuals, is an attempt by the neuromuscular system to provide mechanical stability by stiffening joints. The aim of this study was to investigate the co-activation pattern of the antagonist muscles of the ankle and knee joints during walking in patients with cerebellar ataxia, a neurological disease that strongly affects stability. Kinematic and electromyographic parameters of gait were recorded in 17 patients and 17 controls. Ankle and knee antagonist muscle co-activation indexes were measured throughout the gait cycle and during the sub-phases of gait. The indexes of ataxic patients were compared with those of controls and correlated with clinical and gait variables. Patients showed increased co-activity indexes of both ankle and knee muscles during the gait cycle as well as during the gait sub-phases. Both knee and ankle muscle co-activation indexes were positively correlated with disease severity, while ankle muscle co-activation was also positively correlated with stance and swing duration variability. Significant negative correlations were observed between the number of self-reported falls per year and knee muscle co-activation. The increased co-activation observed in these cerebellar ataxia patients may represent a compensatory strategy serving to reduce gait instability. Indeed, this mechanism allows patients to reduce the occurrence of falls. The need for this strategy, which results in excessive muscle co-contraction, increased metabolic costs and cartilage degeneration processes, could conceivably be overcome through the use of supportive braces specially designed to provide greater joint stability.

  19. A gait stability investigation into FES-assisted paraplegic walking based on the walker tipping index

    NASA Astrophysics Data System (ADS)

    Ming, Dong; Bai, Yanru; Liu, Xiuyun; Qi, Hongzhi; Cheng, Longlong; Wan, Baikun; Hu, Yong; Wong, Yatwa; Luk, Keith D. K.; Leong, John C. Y.

    2009-12-01

    The gait outcome measures used in clinical trials of paraplegic locomotor training determine the effectiveness of improved walking function assisted by the functional electrical stimulation (FES) system. Focused on kinematic, kinetic or physiological changes of paraplegic patients, traditional methods cannot quantify the walking stability or identify the unstable factors of gait in real time. Up until now, the published studies on dynamic gait stability for the effective use of FES have been limited. In this paper, the walker tipping index (WTI) was used to analyze and process gait stability in FES-assisted paraplegic walking. The main instrument was a specialized walker dynamometer system based on a multi-channel strain-gauge bridge network fixed on the frame of the walker. This system collected force information for the handle reaction vector between the patient's upper extremities and the walker during the walking process; the information was then converted into walker tipping index data, which is an evaluation indicator of the patient's walking stability. To demonstrate the potential usefulness of WTI in gait analysis, a preliminary clinical trial was conducted with seven paraplegic patients who were undergoing FES-assisted walking training and seven normal control subjects. The gait stability levels were quantified for these patients under different stimulation patterns and controls under normal walking with knee-immobilization through WTI analysis. The results showed that the walking stability in the FES-assisted paraplegic group was worse than that in the control subject group, with the primary concern being in the anterior-posterior plane. This new technique is practical for distinguishing useful gait information from the viewpoint of stability, and may be further applied in FES-assisted paraplegic walking rehabilitation.

  20. Gait recognition based on Gabor wavelets and modified gait energy image for human identification

    NASA Astrophysics Data System (ADS)

    Huang, Deng-Yuan; Lin, Ta-Wei; Hu, Wu-Chih; Cheng, Chih-Hsiang

    2013-10-01

    This paper proposes a method for recognizing human identity using gait features based on Gabor wavelets and modified gait energy images (GEIs). Identity recognition by gait generally involves gait representation, extraction, and classification. In this work, a modified GEI convolved with an ensemble of Gabor wavelets is proposed as a gait feature. Principal component analysis is then used to project the Gabor-wavelet-based gait features into a lower-dimension feature space for subsequent classification. Finally, support vector machine classifiers based on a radial basis function kernel are trained and utilized to recognize human identity. The major contributions of this paper are as follows: (1) the consideration of the shadow effect to yield a more complete segmentation of gait silhouettes; (2) the utilization of motion estimation to track people when walkers overlap; and (3) the derivation of modified GEIs to extract more useful gait information. Extensive performance evaluation shows a great improvement of recognition accuracy due to the use of shadow removal, motion estimation, and gait representation using the modified GEIs and Gabor wavelets.

  1. 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.

  2. 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. PMID:26049061

  3. Multi-voxel pattern analysis (MVPA) reveals abnormal fMRI activity in both the “core” and “extended” face network in congenital prosopagnosia

    PubMed Central

    Rivolta, Davide; Woolgar, Alexandra; Palermo, Romina; Butko, Marina; Schmalzl, Laura; Williams, Mark A.

    2014-01-01

    The ability to identify faces is mediated by a network of cortical and subcortical brain regions in humans. It is still a matter of debate which regions represent the functional substrate of congenital prosopagnosia (CP), a condition characterized by a lifelong impairment in face recognition, and affecting around 2.5% of the general population. Here, we used functional Magnetic Resonance Imaging (fMRI) to measure neural responses to faces, objects, bodies, and body-parts in a group of seven CPs and ten healthy control participants. Using multi-voxel pattern analysis (MVPA) of the fMRI data we demonstrate that neural activity within the “core” (i.e., occipital face area and fusiform face area) and “extended” (i.e., anterior temporal cortex) face regions in CPs showed reduced discriminability between faces and objects. Reduced differentiation between faces and objects in CP was also seen in the right parahippocampal cortex. In contrast, discriminability between faces and bodies/body-parts and objects and bodies/body-parts across the ventral visual system was typical in CPs. In addition to MVPA analysis, we also ran traditional mass-univariate analysis, which failed to show any group differences in face and object discriminability. In sum, these findings demonstrate (i) face-object representations impairments in CP which encompass both the “core” and “extended” face regions, and (ii) superior power of MVPA in detecting group differences. PMID:25431556

  4. Adaptive locomotor training on an end-effector gait robot: evaluation of the ground reaction forces in different training conditions.

    PubMed

    Tomelleri, Christopher; Waldner, Andreas; Werner, Cordula; Hesse, Stefan

    2011-01-01

    The main goal of robotic gait rehabilitation is the restoration of independent gait. To achieve this goal different and specific patterns have to be practiced intensively in order to stimulate the learning process of the central nervous system. The gait robot G-EO Systems was designed to allow the repetitive practice of floor walking, stair climbing and stair descending. A novel control strategy allows training in adaptive mode. The force interactions between the foot and the ground were analyzed on 8 healthy volunteers in three different conditions: real floor walking on a treadmill, floor walking on the gait robot in passive mode, floor walking on the gait robot in adaptive mode. The ground reaction forces were measured by a Computer Dyno Graphy (CDG) analysis system. The results show different intensities of the ground reaction force across all of the three conditions. The intensities of force interactions during the adaptive training mode are comparable to the real walking on the treadmill. Slight deviations still occur in regard to the timing pattern of the forces. The adaptive control strategy comes closer to the physiological swing phase than the passive mode and seems to be a promising option for the treatment of gait disorders. Clinical trials will validate the efficacy of this new option in locomotor therapy on the patients.

  5. Recognizing Non-Stationary Walking based on Gait Analysis using Laser Scanners

    NASA Astrophysics Data System (ADS)

    Nakamura, Katsuyuki; Shao, Xiaowei; Zhao, Huijing; Shibasaki, Ryosuke

    In this paper the authors propose a method for recognizing non-stationary walking based on a gait analysis using multiple laser range scanners. The proposed method consists of the following procedures: (1) people tracking; (2) detection of gait features; (3) recognition of non-stationary walking. First, people tracking is performed by recognizing patterns in which the range data obtained near ankle rhythmically. Next, gait analysis is performed by the spatio-temporal clustering using Mean Shift algorithm. Finally, One Class Support Vector Machine (One Class SVM) is applied for learning and classifying a non-stationary walking. The experiment in a station concourse in Tokyo shows the overall accuracy of 98.4% by the proposed method.

  6. Computational assessment of combinations of gait modifications for knee osteoarthritis rehabilitation.

    PubMed

    Fregly, Benjamin J

    2008-08-01

    Gait modification is a noninvasive strategy for reducing the external knee adduction torque in patients with medial compartment knee osteoarthritis. Recently, a novel "medial thrust" gait pattern characterized by knee medialization during stance phase has been shown to reduce both adduction torque peaks significantly. While changes in footpath (i.e., toe out angle and stance width) also affect the adduction torque peaks, the extent to which footpath changes may alter the effectiveness of medial thrust gait is unknown. This study used a validated patient-specific computational model to investigate this issue. A dynamic optimization framework that accurately predicted adduction torque changes caused by knee medialization or footpath alteration for a specific patient was modified to predict the simultaneous effect of both factors. Medial thrust gait optimizations were then performed for the same patient using imposed footpath alterations consisting of all possible combinations of three toe out angles (nominal +/- 15 degrees) and three stance widths (nominal +/- 50 mm). Overall, predicted adduction torque reductions produced by medial thrust gait were relatively insensitive to footpath alterations. The 32%-34% reduction in both peaks achieved with the nominal footpath was augmented by at most 9% and reduced by at most 3% for the altered footpaths. When combined with knee medialization, footpath alterations would likely have only a secondary effect on knee adduction torque reductions for this particular patient.

  7. The effects of ramp gait exercise with PNF on stroke patients’ dynamic balance

    PubMed Central

    Seo, Kyo Chul; Kim, Hyeon Ae

    2015-01-01

    [Purpose] This study examined the effects of ramp gait training using lower extremity patterns of proprioceptive neuromuscular facilitation (PNF) on chronic stroke patients’ dynamic balance ability. [Subjects and Methods] In total, 30 stroke patients participated in this study, and they were assigned randomly and equally to an experimental group and a control group. The experimental group received exercise treatment for 30 min and ramp gait training with PNF for 30 min. The control group received exercise treatment for 30 min and ground gait training for 30 min. The interventions were conducted in 30 min sessions, three times per week for four week. The subjects were assessed with the Berg balance scale test, timed up and go test, and functional reach test before and after the experiment and the results were compared. [Results] After the intervention, the BBS and FRT values had significantly increased and the TUG value had significantly decreased in the experimental group; however, the BBS, FRT, and TUG values showed no significant differences in the control group. In addition, differences between the two groups before the intervention and after the intervention were not significant. [Conclusion] In conclusion, ramp gait training with PNF improved stroke patients’ dynamic balance ability, and a good outcome of ramp gait training with PNF is also expected for other neurological system disease patients. PMID:26180312

  8. Effects of visual focus and gait speed on walking balance in the frontal plane.

    PubMed

    Goodworth, Adam; Perrone, Kathryn; Pillsbury, Mark; Yargeau, Michelle

    2015-08-01

    We investigated how head position and gait speed influenced frontal plane balance responses to external perturbations during gait. Thirteen healthy participants walked on a treadmill at three different gait speeds. Visual conditions included either focus downward on lower extremities and walking surface only or focus forward on a stationary scene with horizontal and vertical lines. The treadmill was positioned on a platform that was stationary (non-perturbed) or moving in a pattern that appeared random to the subjects (perturbed). In non-perturbed walking, medial-lateral upper body motion was very similar between visual conditions. However, in perturbed walking, there was significantly less body motion when focus was on the stationary visual scene, suggesting visual feedback of stationary vertical and horizontal cues are particularly important when balance is challenged. Sensitivity of body motion to perturbations was significantly decreased by increasing gait speed, suggesting that faster walking was less sensitive to frontal plane perturbations. Finally, our use of external perturbations supported the idea that certain differences in balance control mechanisms can only be detected in more challenging situations, which is an important consideration for approaches to investigating sensory contribution to balance during gait.

  9. Locomotion studies as an aid in clinical assessment of childhood gait.

    PubMed Central

    Letts, R. M.; Winter, D. A.; Quanbury, A. O.

    1975-01-01

    A clinical locomotion laboratory has been developed to provide quantitative information in the management of gait disorders. The biomedical engineering development of this system identified two major clinical constraints: (a) the need for instrumentation that would not alter the natural gait of the patient and (b) the need for data-processing techniques that would permit analysis and correlation of the large volume of electromyographic (EMg) and kinematic information. The net result has been a unit that incorporates a multichannel telemetry system to capture the EMG and foot-switch information and a television computer system to handle the kinematic information. Gait studies on children with hemiparesis, muscular dystrophy and cerebral palsy have yielded quantitative EMG and kinematic information on the pathomechanics of ambulation in these disorders. Because the information obtained is quantitative, an accurate measure of improvement (or lack of it) after treatment can be documented. Therefore, the locomotion laboratory may have an important role in the preoperative and postoperative evaluation of children whose abnormal gait may require surgical corrective procedures or rehabilitative treatment including the use of prostheses or orthoses. Images FIG. 2 FIG. 4 FIG. 6 FIG. 7 FIG. 8A FIG. 8B PMID:1168537

  10. Wearable sensors used for human gait analysis.

    PubMed

    TarniŢă, Daniela

    2016-01-01

    This paper briefly presents recent developments in the field of wearable sensors and systems that are relevant to the area of normal and pathological human gait analysis. By using wearable sensors, it is possible to monitor the pathological gait disorders and alterations and the changes of balance in the people and prevent or diagnose of different diseases. The most usable wearable sensors and their applications in clinical field are presented based on specialty literature.

  11. Toward understanding the limits of gait recognition

    NASA Astrophysics Data System (ADS)

    Liu, Zongyi; Malave, Laura; Osuntogun, Adebola; Sudhakar, Preksha; Sarkar, Sudeep

    2004-08-01

    Most state of the art video-based gait recognition algorithms start from binary silhouettes. These silhouettes, defined as foreground regions, are usually detected by background subtraction methods, which results in holes or missed parts due to similarity of foreground and background color, and boundary errors due to video compression artifacts. Errors in low-level representation make it hard to understand the effect of certain conditions, such as surface and time, on gait recognition. In this paper, we present a part-level, manual silhouette database consisting of 71 subjects, over one gait cycle, with differences in surface, shoe-type, carrying condition, and time. We have a total of about 11,000 manual silhouette frames. The purpose of this manual silhouette database is twofold. First, this is a resource that we make available at http://www.GaitChallenge.org for use by the gait community to test and design better silhouette detection algorithms. These silhouettes can also be used to learn gait dynamics. Second, using the baseline gait recognition algorithm, which was specified along with the HumanID Gait Challenge problem, we show that performance from manual silhouettes is similar and only sometimes better than that from automated silhouettes detected by statistical background subtraction. Low performances when comparing sequences with differences in walking surfaces and time-variation are not fully explained by silhouette quality. We also study the recognition power in each body part and show that recognition based on just the legs is equal to that from the whole silhouette. There is also significant recognition power in the head and torso shape.

  12. Substantiating Appropriate Motion Capture Techniques for the Assessment of Nordic Walking Gait and Posture in Older Adults.

    PubMed

    Dalton, Christopher M; Nantel, Julie

    2016-05-12

    Nordic walking (NW) has become a safe and simple form of exercise in recent years, and in studying this gait pattern, various data collection techniques have been employed, each with positives and negatives. The aim was to determine the effect of NW on older adult gait and posture and to determine optimal use of different data collection systems in both short and long duration analysis. Gait and posture during NW and normal walking were assessed in 17 healthy older adults (age: 69 ± 7.3). Participants performed two trials of 6 Minute Walk Tests (6MWT) (1 with poles (WP) and 1 without poles (NP)) and 6 trials of a 5m walk (3 WP and 3 NP). Motion was recorded using two systems, a 6-sensor accelerometry system and an 8-camera 3-dimensional motion capture system, in order to quantify spatial-temporal, kinematic, and kinetic parameters. With both systems, participants demonstrated increased stride length and double support and decreased gait speed and cadence WP compared to NP (p <0.05). Also, with motion capture, larger single support time was found WP (p <0.05). With 3-D capture, smaller hip power generation and moments of force were found at heel contact and pre-swing as well as smaller knee power absorption at heel contact, pre-swing, and terminal swing WP compared to NP, when assessed over one cycle (p <0.05). Also, WP yielded smaller moments of force at heel contact and terminal swing along with larger moments at mid-stance of a gait cycle (p <0.05). No changes were found for posture. NW seems appropriate for promoting a normal gait pattern in older adults. Three-dimensional motion capture should primarily be used during short duration gait analysis (i.e. single gait cycle), while accelerometry systems should be primarily employed in instances requiring longer duration analysis such as during the 6MWT.

  13. Substantiating Appropriate Motion Capture Techniques for the Assessment of Nordic Walking Gait and Posture in Older Adults.

    PubMed

    Dalton, Christopher M; Nantel, Julie

    2016-01-01

    Nordic walking (NW) has become a safe and simple form of exercise in recent years, and in studying this gait pattern, various data collection techniques have been employed, each with positives and negatives. The aim was to determine the effect of NW on older adult gait and posture and to determine optimal use of different data collection systems in both short and long duration analysis. Gait and posture during NW and normal walking were assessed in 17 healthy older adults (age: 69 ± 7.3). Participants performed two trials of 6 Minute Walk Tests (6MWT) (1 with poles (WP) and 1 without poles (NP)) and 6 trials of a 5m walk (3 WP and 3 NP). Motion was recorded using two systems, a 6-sensor accelerometry system and an 8-camera 3-dimensional motion capture system, in order to quantify spatial-temporal, kinematic, and kinetic parameters. With both systems, participants demonstrated increased stride length and double support and decreased gait speed and cadence WP compared to NP (p <0.05). Also, with motion capture, larger single support time was found WP (p <0.05). With 3-D capture, smaller hip power generation and moments of force were found at heel contact and pre-swing as well as smaller knee power absorption at heel contact, pre-swing, and terminal swing WP compared to NP, when assessed over one cycle (p <0.05). Also, WP yielded smaller moments of force at heel contact and terminal swing along with larger moments at mid-stance of a gait cycle (p <0.05). No changes were found for posture. NW seems appropriate for promoting a normal gait pattern in older adults. Three-dimensional motion capture should primarily be used during short duration gait analysis (i.e. single gait cycle), while accelerometry systems should be primarily employed in instances requiring longer duration analysis such as during the 6MWT. PMID:27214263

  14. Gait Partitioning Methods: A Systematic Review

    PubMed Central

    Taborri, Juri; Palermo, Eduardo; Rossi, Stefano; Cappa, Paolo

    2016-01-01

    In the last years, gait phase partitioning has come to be a challenging research topic due to its impact on several applications related to gait technologies. A variety of sensors can be used to feed algorithms for gait phase partitioning, mainly classifiable as wearable or non-wearable. Among wearable sensors, footswitches or foot pressure insoles are generally considered as the gold standard; however, to overcome some inherent limitations of the former, inertial measurement units have become popular in recent decades. Valuable results have been achieved also though electromyography, electroneurography, and ultrasonic sensors. Non-wearable sensors, such as opto-electronic systems along with force platforms, remain the most accurate system to perform gait analysis in an indoor environment. In the present paper we identify, select, and categorize the available methodologies for gait phase detection, analyzing advantages and disadvantages of each solution. Finally, we comparatively examine the obtainable gait phase granularities, the usable computational methodologies and the optimal sensor placements on the targeted body segments. PMID:26751449

  15. Gait Partitioning Methods: A Systematic Review.

    PubMed

    Taborri, Juri; Palermo, Eduardo; Rossi, Stefano; Cappa, Paolo

    2016-01-01

    In the last years, gait phase partitioning has come to be a challenging research topic due to its impact on several applications related to gait technologies. A variety of sensors can be used to feed algorithms for gait phase partitioning, mainly classifiable as wearable or non-wearable. Among wearable sensors, footswitches or foot pressure insoles are generally considered as the gold standard; however, to overcome some inherent limitations of the former, inertial measurement units have become popular in recent decades. Valuable results have been achieved also though electromyography, electroneurography, and ultrasonic sensors. Non-wearable sensors, such as opto-electronic systems along with force platforms, remain the most accurate system to perform gait analysis in an indoor environment. In the present paper we identify, select, and categorize the available methodologies for gait phase detection, analyzing advantages and disadvantages of each solution. Finally, we comparatively examine the obtainable gait phase granularities, the usable computational methodologies and the optimal sensor placements on the targeted body segments. PMID:26751449

  16. In Vivo Gait Analysis During Bone Transport.

    PubMed

    Mora-Macías, J; Reina-Romo, E; Morgaz, J; Domínguez, J

    2015-09-01

    The load bearing characteristics of the intervened limb over time in vivo are important to know in distraction osteogenesis and bone healing for the characterization of the bone maturation process. Gait analyses were performed for a group of sheep in which bone transport was carried out. The ground reaction force was measured by means of a force platform, and the gait parameters (i.e., the peak, the mean vertical ground reaction force and the impulse) were calculated during the stance phase for each limb. The results showed that these gait parameters decreased in the intervened limb and interestingly increased in the other limbs due to the implantation of the fixator. Additionally, during the process, the gait parameters exponentially approached the values for healthy animals. Corresponding radiographies showed an increasing level of ossification in the callus. This study shows, as a preliminary approach to be confirmed with more experiments, that gait analysis could be used as an alternative method to control distraction osteogenesis or bone healing. For example, these analyses could determine the appropriate time to remove the fixator. Furthermore, gait analysis has advantages over other methods because it provides quantitative data and does not require instrumented fixators.

  17. Gait Recognition Using Wearable Motion Recording Sensors

    NASA Astrophysics Data System (ADS)

    Gafurov, Davrondzhon; Snekkenes, Einar

    2009-12-01

    This paper presents an alternative approach, where gait is collected by the sensors attached to the person's body. Such wearable sensors record motion (e.g. acceleration) of the body parts during walking. The recorded motion signals are then investigated for person recognition purposes. We analyzed acceleration signals from the foot, hip, pocket and arm. Applying various methods, the best EER obtained for foot-, pocket-, arm- and hip- based user authentication were 5%, 7%, 10% and 13%, respectively. Furthermore, we present the results of our analysis on security assessment of gait. Studying gait-based user authentication (in case of hip motion) under three attack scenarios, we revealed that a minimal effort mimicking does not help to improve the acceptance chances of impostors. However, impostors who know their closest person in the database or the genders of the users can be a threat to gait-based authentication. We also provide some new insights toward the uniqueness of gait in case of foot motion. In particular, we revealed the following: a sideway motion of the foot provides the most discrimination, compared to an up-down or forward-backward directions; and different segments of the gait cycle provide different level of discrimination.

  18. Reliability and validity of Edinburgh visual gait score as an evaluation tool for children with cerebral palsy.

    PubMed

    Del Pilar Duque Orozco, Maria; Abousamra, Oussama; Church, Chris; Lennon, Nancy; Henley, John; Rogers, Kenneth J; Sees, Julieanne P; Connor, Justin; Miller, Freeman

    2016-09-01

    Assessment of gait abnormalities in cerebral palsy (CP) is challenging, and access to instrumented gait analysis is not always feasible. Therefore, many observational gait analysis scales have been devised. This study aimed to evaluate the interobserver reliability, intraobserver reliability, and validity of Edinburgh visual gait score (EVGS). Video of 30 children with spastic CP were reviewed by 7 raters (10 children each in GMFCS levels I, II, and III, age 6-12 years). Three observers had high level of experience in gait analysis (10+ years), two had medium level (2-5 years) and two had no previous experience (orthopedic fellows). Interobserver reliability was evaluated using percentage of complete agreement and kappa values. Criterion validity was evaluated by comparing EVGS scores with 3DGA data taken from the same video visit. Interobserver agreement was 60-90% and Kappa values were 0.18-0.85 for the 17 items in EVGS. Reliability was higher for distal segments (foot/ankle/knee 63-90%; trunk/pelvis/hip 60-76%), with greater experience (high 66-91%, medium 62-90%, no-experience 41-87%), with more EVGS practice (1st 10 videos 52-88%, last 10 videos 64-97%) and when used with higher functioning children (GMFCS I 65-96%, II 58-90%, III 35-65%). Intraobserver agreement was 64-92%. Agreement between EVGS and 3DGA was 52-73%. We believe that having EVGS as part of the standardized gait evaluation is helpful in optimizing the visual scoring. EVGS can be a supportive tool that adds quantitative data instead of only qualitative assessment to a video only gait evaluation. PMID:27344448

  19. A Validated Smartphone-Based Assessment of Gait and Gait Variability in Parkinson’s Disease

    PubMed Central

    Ellis, Robert J.; Ng, Yee Sien; Zhu, Shenggao; Tan, Dawn M.; Anderson, Boyd; Schlaug, Gottfried; Wang, Ye

    2015-01-01

    Background A well-established connection exists between increased gait variability and greater fall likelihood in Parkinson’s disease (PD); however, a portable, validated means of quantifying gait variability (and testing the efficacy of any intervention) remains lacking. Furthermore, although rhythmic auditory cueing continues to receive attention as a promising gait therapy for PD, its widespread delivery remains bottlenecked. The present paper describes a smartphone-based mobile application (“SmartMOVE”) to address both needs. Methods The accuracy of smartphone-based gait analysis (utilizing the smartphone’s built-in tri-axial accelerometer and gyroscope to calculate successive step times and step lengths) was validated against two heel contact–based measurement devices: heel-mounted footswitch sensors (to capture step times) and an instrumented pressure sensor mat (to capture step lengths). 12 PD patients and 12 age-matched healthy controls walked along a 26-m path during self-paced and metronome-cued conditions, with all three devices recording simultaneously. Results Four outcome measures of gait and gait variability were calculated. Mixed-factorial analysis of variance revealed several instances in which between-group differences (e.g., increased gait variability in PD patients relative to healthy controls) yielded medium-to-large effect sizes (eta-squared values), and cueing-mediated changes (e.g., decreased gait variability when PD patients walked with auditory cues) yielded small-to-medium effect sizes—while at the same time, device-related measurement error yielded small-to-negligible effect sizes. Conclusion These findings highlight specific opportunities for smartphone-based gait analysis to serve as an alternative to conventional gait analysis methods (e.g., footswitch systems or sensor-embedded walkways), particularly when those methods are cost-prohibitive, cumbersome, or inconvenient. PMID:26517720

  20. Dynamic stability and phase resetting during biped gait

    NASA Astrophysics Data System (ADS)

    Nomura, Taishin; Kawa, Kazuyoshi; Suzuki, Yasuyuki; Nakanishi, Masao; Yamasaki, Taiga

    2009-06-01

    Dynamic stability during periodic biped gait in humans and in a humanoid robot is considered. Here gait systems of human neuromusculoskeletal system and a humanoid are simply modeled while keeping their mechanical properties plausible. We prescribe periodic gait trajectories in terms of joint angles of the models as a function of time. The equations of motion of the models are then constrained by one of the prescribed gait trajectories to obtain types of periodically forced nonlinear dynamical systems. Simulated gait of the models may or may not fall down during gait, since the constraints are made only for joint angles of limbs but not for the motion of the body trunk. The equations of motion can exhibit a limit cycle solution (or an oscillatory solution that can be considered as a limit cycle practically) for each selected gait trajectory, if an initial condition is set appropriately. We analyze the stability of the limit cycle in terms of Poincaré maps and the basin of attraction of the limit cycle in order to examine how the stability depends on the prescribed trajectory. Moreover, the phase resetting of gait rhythm in response to external force perturbation is modeled. Since we always prescribe a gait trajectory in this study, reacting gait trajectories during the phase resetting are also prescribed. We show that an optimally prescribed reacting gait trajectory with an appropriate amount of the phase resetting can increase the gait stability. Neural mechanisms for generation and modulation of the gait trajectories are discussed.

  1. Postural and gait performance in children with attention deficit/hyperactivity disorder.

    PubMed

    Buderath, Paul; Gärtner, Kristina; Frings, Markus; Christiansen, Hanna; Schoch, Beate; Konczak, Jürgen; Gizewski, Elke R; Hebebrand, Johannes; Timmann, Dagmar

    2009-02-01

    Up to 50% of children and adolescents with attention deficit/hyperactivity disorder (ADHD) exhibit motor abnormalities including altered balance. Results from brain imaging studies indicate that these balance deficits could be of cerebellar origin as ADHD children may show atrophy in those regions of the cerebellum associated with gait and balance control. To address this question, this study investigated postural and gait abilities in ADHD children and compared their static and dynamic balance with children with known lesions in the cerebellum. Children diagnosed with ADHD according to DSM IV-TR diagnostic criteria were compared with children with chronic surgical cerebellar lesions and age-matched controls. A movement coordination test was used to assess differences in motor development. Postural and gait abilities were assessed using posturography, treadmill walking and a paced stepping task. Volumes of the cerebellum and the cerebrum were assessed on the basis of 3D magnetic resonance images (MRI). Children with cerebellar lesions showed significant performance decrements in all tasks compared with the controls, particularly in the movement coordination test and paced stepping task. During dynamic posturography ADHD-participants showed mild balance problems which correlated with findings in cerebellar children. ADHD children showed abnormalities in a backward walking task and minor abnormalities in the paced stepping test. They did not differ in treadmill walking from the controls. These findings support the notion that cerebellar dysfunction may contribute to the postural deficits seen in ADHD children. However, the observed abnormalities were minor. It needs to be examined whether balance problems become more pronounced in ADHD children exhibiting more prominent signs of clumsiness.

  2. Pattern of extrapyramidal signs in Alzheimer's disease.

    PubMed

    Tosto, Giuseppe; Monsell, Sarah E; Hawes, Stephen E; Mayeux, Richard

    2015-11-01

    Patients with Alzheimer's disease (AD) often develop extrapyramidal signs (EPS), which increase in frequency as the disease progresses. We aimed to investigate the patterns of presentation of EPS in AD and their correlation with clinical and neuropathological features. 4284 subjects diagnosed with AD from the National Alzheimer's Coordinating Center (NACC) database with at least one abnormal Unified Parkinson's Disease Rating Scale (UPDRS) assessment were included. Individuals were assigned to a discovery sample and a sensitivity analysis sample (moderate and mild dementia, respectively) and a subset of subjects provided neuropathological data (n = 284). Individuals from the Washington Heights and Inwood Columbia Aging Project (WHICAP) served as validation sample. Patterns of presentation of EPS were identified employing categorical principal component analysis (CATPCA). Six principal components were identified in both mild and moderate AD samples: (I) hand movements, alternating movements, finger tapping, leg agility ("limbs bradykinesia"); (II) posture, postural instability, arising from chair, gait and body bradykinesia/hypokinesia ("axial"); (III) limb rigidity ("rigidity"); (IV) postural tremor; (V) resting tremor; (VI) speech and facial expression. Similar results were obtained in the WHICAP cohort. Individuals with hallucinations, apathy, aberrant night behaviors and more severe dementia showed higher axial and limb bradykinesia scores. "Limb bradykinesia" component was associated with a neuropathological diagnosis of Lewy body disease and "axial" component with reduced AD-type pathology. Patterns of EPS in AD show distinct clinical and neuropathological correlates; they share a pattern of presentation similar to that seen in Parkinson's disease, suggesting common pathogenic mechanisms across neurodegenerative diseases. PMID:26338814

  3. The effect of tibial torsion on the dynamic function of the soleus during gait.

    PubMed

    Schwartz, Michael; Lakin, Gaio

    2003-04-01

    An induced acceleration analysis (IAA) model was used to investigate the effect of tibial torsion on the ability of the soleus to support and propel the body during gait. The IAA approach is well suited for this study because it allows soleus action to be quantified in the presence of varying amounts of tibial torsion, while other factors such as body configuration and muscle activation are held constant. The results of the analysis showed that excess tibial torsion shifts the induced knee joint accelerations toward flexion, valgus and external rotation, and diminishes body center-of-mass support and propulsion. This analysis supports the concept that bony mal-alignment can lead to 'lever arm dysfunction'. The objective data correlate with previous clinical observations related to valgus stress, crouch and the role of the soleus in level walking. The IAA model provides a tool for examining various aspects of abnormal gait independently and quantitatively.

  4. Robotic gait rehabilitation and substitution devices in neurological disorders: where are we now?

    PubMed

    Calabrò, Rocco Salvatore; Cacciola, Alberto; Bertè, Francesco; Manuli, Alfredo; Leo, Antonino; Bramanti, Alessia; Naro, Antonino; Milardi, Demetrio; Bramanti, Placido

    2016-04-01

    Gait abnormalities following neurological disorders are often disabling, negatively affecting patients' quality of life. Therefore, regaining of walking is considered one of the primary objectives of the rehabilitation process. To overcome problems related to conventional physical therapy, in the last years there has been an intense technological development of robotic devices, and robotic rehabilitation has proved to play a major role in improving one's ability to walk. The robotic rehabilitation systems can be classified into stationary and overground walking systems, and several studies have demonstrated their usefulness in patients after severe acquired brain injury, spinal cord injury and other neurological diseases, including Parkinson's disease, multiple sclerosis and cerebral palsy. In this review, we want to highlight which are the most widely used devices today for gait neurological rehabilitation, focusing on their functioning, effectiveness and challenges. Novel and promising rehabilitation tools, including the use of virtual reality, are also discussed. PMID:26781943

  5. Robotic gait rehabilitation and substitution devices in neurological disorders: where are we now?

    PubMed

    Calabrò, Rocco Salvatore; Cacciola, Alberto; Bertè, Francesco; Manuli, Alfredo; Leo, Antonino; Bramanti, Alessia; Naro, Antonino; Milardi, Demetrio; Bramanti, Placido

    2016-04-01

    Gait abnormalities following neurological disorders are often disabling, negatively affecting patients' quality of life. Therefore, regaining of walking is considered one of the primary objectives of the rehabilitation process. To overcome problems related to conventional physical therapy, in the last years there has been an intense technological development of robotic devices, and robotic rehabilitation has proved to play a major role in improving one's ability to walk. The robotic rehabilitation systems can be classified into stationary and overground walking systems, and several studies have demonstrated their usefulness in patients after severe acquired brain injury, spinal cord injury and other neurological diseases, including Parkinson's disease, multiple sclerosis and cerebral palsy. In this review, we want to highlight which are the most widely used devices today for gait neurological rehabilitation, focusing on their functioning, effectiveness and challenges. Novel and promising rehabilitation tools, including the use of virtual reality, are also discussed.

  6. Listenmee and Listenmee smartphone application: synchronizing walking to rhythmic auditory cues to improve gait in Parkinson's disease.

    PubMed

    Lopez, William Omar Contreras; Higuera, Carlos Andres Escalante; Fonoff, Erich Talamoni; Souza, Carolina de Oliveira; Albicker, Ulrich; Martinez, Jairo Alberto Espinoza

    2014-10-01

    Evidence supports the use of rhythmic external auditory signals to improve gait in PD patients (Arias & Cudeiro, 2008; Kenyon & Thaut, 2000; McIntosh, Rice & Thaut, 1994; McIntosh et al., 1997; Morris, Iansek, & Matyas, 1994; Thaut, McIntosh, & Rice, 1997; Suteerawattananon, Morris, Etnyre, Jankovic, & Protas , 2004; Willems, Nieuwboer, Chavert, & Desloovere, 2006). However, few prototypes are available for daily use, and to our knowledge, none utilize a smartphone application allowing individualized sounds and caden