Improved lower extremity pedaling mechanics in individuals with stroke under maximal workloads.

PubMed

Linder, Susan M; Rosenfeldt, Anson B; Bazyk, Andrew S; Koop, Mandy Miller; Ozinga, Sarah; Alberts, Jay L

2018-05-01

Background Individuals with stroke present with motor control deficits resulting in the abnormal activation and timing of agonist and antagonist muscles and inefficient movement patterns. The analysis of pedaling biomechanics provides a window into understanding motor control deficits, which vary as a function of workload. Understanding the relationship between workload and motor control is critical when considering exercise prescription during stroke rehabilitation. Objectives To characterize pedaling kinematics and motor control processes under conditions in which workload was systematically increased to an eventual patient-specific maximum. Methods A cohort study was conducted in which 18 individuals with chronic stroke underwent a maximal exertion cardiopulmonary exercise test on a stationary cycle ergometer, during which pedaling torque was continuously recorded. Measures of force production, pedaling symmetry, and pedaling smoothness were obtained. Results Mean Torque increased significantly (p < 0.05) for both legs from initial to terminal workloads. Mean torque Symmetry Index, calculated for down and upstroke portions of the pedaling action, improved from 0.37(0.29) to 0.29(0.35) during downstroke (p = 0.007), and worsened during the upstroke: -0.37(0.38) to -0.62(0.46) (p < 0.001) from initial to terminal workloads. Low Torque Duration improved from initial to terminal workloads, decreasing from 121.1(52.9) to 58.1(39.6) degrees (p < 0.001), respectively. Smoothness of pedaling improved significantly from initial to terminal workloads (p < 0.001). Conclusions Improved pedaling kinematics at terminal workloads indicate that individuals with stroke demonstrate improved motor control with respect to the timing, sequencing, and activation of hemiparetic lower extremity musculature compared to lower workloads. Therapeutic prescription involving higher resistance may be necessary to sufficiently engage and activate the paretic lower extremity.

Heel and toe driving on fuel cell vehicle

DOEpatents

Choi, Tayoung; Chen, Dongmei

2012-12-11

A system and method for providing nearly instantaneous power in a fuel cell vehicle. The method includes monitoring the brake pedal angle and the accelerator pedal angle of the vehicle, and if the vehicle driver is pressing both the brake pedal and the accelerator pedal at the same time and the vehicle is in a drive gear, activating a heel and toe mode. When the heel and toe mode is activated, the speed of a cathode compressor is increased to a predetermined speed set-point, which is higher than the normal compressor speed for the pedal position. Thus, when the vehicle brake is removed, the compressor speed is high enough to provide enough air to the cathode, so that the stack can generate nearly immediate power.

Close up view of the pair of Rudder Pedals in ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Close up view of the pair of Rudder Pedals in the Commander's Satiation on the Flight Deck of the Orbiter Discovery. The rudder pedals command orbiter acceleration in yaw by positioning the rudder during atmospheric flight. However, because the flight control software automatically performs turn coordination during banking maneuvers, the rudder pedals are not operationally used during glided flight. It is not until after touchdown that the crew uses them for nose wheel steering during rollout. Depressing the upper portion of the rudder pedals provides braking. Differential braking may also be used for directional control during rollout. This view was take at Johnson Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

Sensorimotor state of the contralateral leg affects ipsilateral muscle coordination of pedaling.

PubMed

Ting, L H; Raasch, C C; Brown, D A; Kautz, S A; Zajac, F E

1998-09-01

The objective of this study was to determine if independent central pattern generating elements controlling the legs in bipedal and unipedal locomotion is a viable theory for locomotor propulsion in humans. Coordinative coupling of the limbs could then be accomplished through mechanical interactions and ipsilateral feedback control rather than through central interlimb neural pathways. Pedaling was chosen as the locomotor task to study because interlimb mechanics can be significantly altered, as pedaling can be executed with the use of either one leg or two legs (cf. walking) and because the load on the limb can be well-controlled. Subjects pedaled a modified bicycle ergometer in a two-legged (bilateral) and a one-legged (unilateral) pedaling condition. The loading on the leg during unilateral pedaling was designed to be identical to the loading experienced by the leg during bilateral pedaling. This loading was achieved by having a trained human "motor" pedal along with the subject and exert on the opposite crank the torque that the subject's contralateral leg generated in bilateral pedaling. The human "motor" was successful at reproducing each subject's one-leg crank torque. The shape of the motor's torque trajectory was similar to that of subjects, and the amount of work done during extension and flexion was not significantly different. Thus the same muscle coordination pattern would allow subjects to pedal successfully in both the bilateral and unilateral conditions, and the afferent signals from the pedaling leg could be the same for both conditions. Although the overall work done by each leg did not change, an 86% decrease in retarding (negative) crank torque during limb flexion was measured in all 11 subjects during the unilateral condition. This corresponded to an increase in integrated electromyography of tibialis anterior (70%), rectus femoris (43%), and biceps femoris (59%) during flexion. Even given visual torque feedback in the unilateral condition, subjects still showed a 33% decrease in negative torque during flexion. These results are consistent with the existence of an inhibitory pathway from elements controlling extension onto contralateral flexion elements, with the pathway operating during two-legged pedaling but not during one-legged pedaling, in which case flexor activity increases. However, this centrally mediated coupling can be overcome with practice, as the human "motor" was able to effectively match the bilateral crank torque after a longer practice regimen. We conclude that the sensorimotor control of a unipedal task is affected by interlimb neural pathways. Thus a task performed unilaterally is not performed with the same muscle coordination utilized in a bipedal condition, even if such coordination would be equally effective in the execution of the unilateral task.

Drivers' Visual Search Behavior Toward Vulnerable Road Users at Junctions as a Function of Cycling Experience.

PubMed

Robbins, Chloe Jade; Chapman, Peter

2018-06-01

The current study investigated the behavior and visual attention of two groups of drivers with differing pedal cycling experience (pedal cyclists and nonpedal cyclists) towards vulnerable road users at junctions in a driving simulator. Pedal cyclists and motorcyclists are involved in a disproportionate number of crashes given the distance they travel, with a high proportion of these crashes occurring at junctions. Many studies have found that car drivers who also hold a motorcycle license have increased awareness towards motorcycles. The task involved approaching a T-junction and turning right when it was deemed to be safe. In Study 1, the junction was controlled by a give way sign, and in Study 2, the junction was controlled by a stop sign. Each T-junction contained a target vehicle (car, motorcycle, or pedal cycle), approaching from a near, medium, or far distance from the junction. Participants did not look at pedal cycles approaching from a far distance for as long as they looked at approaching motorcycles and cars, despite all vehicles travelling at identical speeds. No differences were found between pedal cyclists and nonpedal cyclists on any visual attention measures, indicating that pedal cycling experience was not associated with differences in drivers' attention toward pedal cycles. Findings have implications for road safety, demonstrating subtle differences in drivers' everyday visual attention toward differing vehicle types. This research has the potential to inform the development of in-car technical assistive systems, improving the safety of vulnerable road users at junctions.

Phase reversal of biomechanical functions and muscle activity in backward pedaling.

PubMed

Ting, L H; Kautz, S A; Brown, D A; Zajac, F E

1999-02-01

Computer simulations of pedaling have shown that a wide range of pedaling tasks can be performed if each limb has the capability of executing six biomechanical functions, which are arranged into three pairs of alternating antagonistic functions. An Ext/Flex pair accelerates the limb into extension or flexion, a Plant/Dorsi pair accelerates the foot into plantarflexion or dorsiflexion, and an Ant/Post pair accelerates the foot anteriorly or posteriorly relative to the pelvis. Because each biomechanical function (i.e., Ext, Flex, Plant, Dorsi, Ant, or Post) contributes to crank propulsion during a specific region in the cycle, phasing of a muscle is hypothesized to be a consequence of its ability to contribute to one or more of the biomechanical functions. Analysis of electromyogram (EMG) patterns has shown that this biomechanical framework assists in the interpretation of muscle activity in healthy and hemiparetic subjects during forward pedaling. Simulations show that backward pedaling can be produced with a phase shift of 180 degrees in the Ant/Post pair. No phase shifts in the Ext/Flex and Plant/Dorsi pairs are then necessary. To further test whether this simple yet biomechanically viable strategy may be used by the nervous system, EMGs from 7 muscles in 16 subjects were measured during backward as well as forward pedaling. As predicted, phasing in vastus medialis (VM), tibialis anterior (TA), medial gastrocnemius (MG), and soleus (SL) were unaffected by pedaling direction, with VM and SL contributing to Ext, MG to Plant, and TA to Dorsi. In contrast, phasing in biceps femoris (BF) and semimembranosus (SM) were affected by pedaling direction, as predicted, compatible with their contribution to the directionally sensitive Post function. Phasing of rectus femoris (RF) was also affected by pedaling direction; however, its ability to contribute to the directionally sensitive Ant function may only be expressed in forward pedaling. RF also contributed significantly to the directionally insensitive Ext function in both forward and backward pedaling. Other muscles also appear to have contributed to more than one function, which was especially evident in backward pedaling (i.e. , BF, SM, MG, and TA to Flex). We conclude that the phasing of only the Ant and Post biomechanical functions are directionally sensitive. Further, we suggest that task-dependent modulation of the expression of the functions in the motor output provides this biomechanics-based neural control scheme with the capability to execute a variety of lower limb tasks, including walking.

An Efficient Energy Management Strategy, Unique Power Split & Energy Distribution, Based on Calculated Vehicle Road Loads

DTIC Science & Technology

2012-08-01

HMMWV for the current given inputs based on the current vehicle speed, acceleration pedal , and brake pedal . From this driver requested power at the...HMMWV engine, b) base HMMWV gear ratios of the 4 speed transmission, c) acceleration and brake pedal pressed for the hybrid vehicle and d) Torque...coefficient. µb: Threshold for detecting brake pedal pressed ? 2 tanE4FGH 2 tanE4 I [K ρ: Air mass density, ρ = ma/Va where ma is mass of air

[Pedal bypass using venous allograft].

PubMed

Pluháčková, H; Staffa, R; Konečný, Z; Kříž, Z; Vlachovský, R

Pedal or distal crural bypass surgery for limb salvage is a method with very good long-term results. For patients in whom a suitable autologous venous graft is not available, the use of a venous allograft is an alternative procedure. A 68 years old man with ischaemic disease of lower extremities and gangrene of the left foot was admitted to our Centre in August 2014. He underwent percutaneous transluminal angioplasty of crural arteries of his left lower extremity. This, however, failed to improve peripheral circulation. The patient was then indicated for pedal or distal crural vascular reconstruction. Since no suitable autologous vein was available, distal bypass surgery using a donor graft remained the only option for limb salvage. Amputation of the toes on the left foot due to gangrene was necessary. Subsequently, femoro-pedal bypass to the left common plantar artery was performed using a great saphenous vein allograft. The post-operative course was without complications, the pedal bypass was patent and toe amputation was with good healing. The patient remained in follow-up care. A good outcome of vascular reconstruction with an allograft depends on the availability of a suitable allograft and good patient compliance with post-operative care. In the case presented here, the pedal bypass grafting by means of an allograft helped to save the patients limb. pedal bypass venous allograft limb salvage.

Underwater Cycle Ergometry: Power Requirements With and Without Diver Thermal Dress

DTIC Science & Technology

2009-01-01

waterproofed Collins Pedal Mate ergometers that are no longer available. A pedal shaft drives the shaft of a hysteresis brake (HB210, Magtrol; Buffalo, NY...NEDU, regular bicycle pedals with toe straps/ over canvas shoes were used in Buffalo (personal 13 communication). The foot cups used at NEDU are

Cycling biomechanics: a literature review.

PubMed

Wozniak Timmer, C A

1991-01-01

Submitted in partial fulfillment for a Master of Science degree at the University of Pittsburgh, School of Health Related Professions, Pittsburgh, PA 1.5213 This review of current literature on cycling biomechanics emphasizes lower extremity muscle actions and joint excursions, seat height, pedal position, pedaling rate, force application, and pedaling symmetry. Guidelines are discussed for optimal seat height, pedal position, and pedaling rate. Force application in the power and recovery phases of cycling and the relationship of force application to pedaling symmetry are discussed. The need for a biomechanical approach to cycling exists since a great deal of the literature is primarily physiologic in nature. The purpose of this review is to make cyclists and their advisors aware of the biomechanics of cycling and guidelines to follow. This approach is also important because cycling is a very common form of exercise prescribed by physical therapists for clinic or home programs. Biomechanical aspects of cycling should be considered by cyclists at any level of participation and by physical therapists in order for goal-oriented, efficient cycling to occur. J Orthop Sports Phys Ther 1991;14(3):106-113.

Histological, chemical and behavioural evidence of pedal communication in brown bears.

PubMed

Sergiel, Agnieszka; Naves, Javier; Kujawski, Piotr; Maślak, Robert; Serwa, Ewa; Ramos, Damián; Fernández-Gil, Alberto; Revilla, Eloy; Zwijacz-Kozica, Tomasz; Zięba, Filip; Painer, Johanna; Selva, Nuria

2017-04-21

Most mammals rely upon scent for intraspecific communication. As most bear species have large home ranges and are non-territorial, scent deposit while walking could be an effective way to communicate with conspecifics. Here, we investigate the existence of pedal glands in brown bears and their role in chemical communication from a histological, biochemical and behavioural perspective. We found eccrine glands in footpads, and prominent apocrine and sebaceous glands in the interdigital, metacarpal and metatarsal skin sections. Pedal scent contained 26 compounds including carboxylic acids, important constituents of mammalian secretions. Six of these compounds were exclusive for males. Finally, we describe a specific marking gait recorded in the field, mostly performed by males. Our study supports the existence of chemical communication through pedal marking in brown bears and suggests sex-coding potential of pedal scent.

Fatigue during maximal sprint cycling: unique role of cumulative contraction cycles.

PubMed

Tomas, Aleksandar; Ross, Emma Z; Martin, James C

2010-07-01

Maximal cycling power has been reported to decrease more rapidly when performed with increased pedaling rates. Increasing pedaling rate imposes two constraints on the neuromuscular system: 1) decreased time for muscle excitation and relaxation and 2) increased muscle shortening velocity. Using two crank lengths allows the effects of time and shortening velocity to be evaluated separately. We conducted this investigation to determine whether the time available for excitation and relaxation or the muscle shortening velocity was mainly responsible for the increased rate of fatigue previously observed with increased pedaling rates and to evaluate the influence of other possible fatiguing constraints. Seven trained cyclists performed 30-s maximal isokinetic cycling trials using two crank lengths: 120 and 220 mm. Pedaling rate was optimized for maximum power for each crank length: 135 rpm for the 120-mm cranks (1.7 m x s(-1) pedal speed) and 109 rpm for the 220-mm cranks (2.5 m x s(-1) pedal speed). Power was recorded with an SRM power meter. Crank length did not affect peak power: 999 +/- 276 W for the 120-mm crank versus 1001 +/- 289 W for the 220-mm crank. Fatigue index was greater (58.6% +/- 3.7% vs 52.4% +/- 4.8%, P < 0.01), and total work was less (20.0 +/- 1.8 vs 21.4 +/- 2.0 kJ, P < 0.01) with the higher pedaling rate-shorter crank condition. Regression analyses indicated that the power for the two conditions was most highly related to cumulative work (r2 = 0.94) and to cumulative cycles (r2 = 0.99). These results support previous findings and confirm that pedaling rate, rather than pedal speed, was the main factor influencing fatigue. Our novel result was that power decreased by a similar increment with each crank revolution for the two conditions, indicating that each maximal muscular contraction induced a similar amount of fatigue.

Force-velocity relationship in cycling revisited: benefit of two-dimensional pedal forces analysis.

PubMed

Dorel, Sylvain; Couturier, Antoine; Lacour, Jean-René; Vandewalle, Henry; Hautier, Christophe; Hug, François

2010-06-01

Maximal cycling exercise has been widely used to describe the power-velocity characteristics of lower-limb extensor muscles. This study investigated the contribution of each functional sector (i.e., extension, flexion, and transitions sectors) on the total force produced over a complete pedaling cycle. We also examined the ratio of effective force to the total pedal force, termed index of mechanical effectiveness (IE), in explaining differences in power between subjects. Two-dimensional pedal forces and crank angles were measured during a cycling force-velocity test performed by 14 active men. Mean values of forces, power output, and IE over four functional angular sectors were assessed: top = 330 degrees -30 degrees , downstroke = 30 degrees -150 degrees , bottom = 150 degrees -210 degrees , and upstroke = 210 degrees -330 degrees . Linear and quadratic force-velocity and power-velocity relationships were obtained for downstroke and upstroke. Maximal power output (Pmax) generated over these two sectors represented, respectively, 73.6% +/- 2.6% and 10.3% +/- 1.8% of Pmax assessed over the entire cycle. In the whole group, Pmax over the complete cycle was significantly related to Pmax during the downstroke and upstroke. IE significantly decreased with pedaling rate, especially in bottom and upstroke. There were significant relationships between power output and IE for top and upstroke when the pedaling rate was below or around the optimal value and in all the sectors at very high cadences. Although data from force-velocity test primarily characterize the muscular function involved in the downstroke phase, they also reflect the flexor muscles' ability to actively pull on the pedal during the upstroke. IE influences the power output in the upstroke phase and near the top dead center, and IE accounts for differences in power between subjects at high pedaling rates.

EEG during pedaling: Evidence for cortical control of locomotor tasks

PubMed Central

Jain, Sanket; Gourab, Krishnaj; Schindler-Ivens, Sheila; Schmit, Brian D.

2014-01-01

Objective This study characterized the brain electrical activity during pedaling, a locomotor-like task, in humans. We postulated that phasic brain activity would be associated with active pedaling, consistent with a cortical role in locomotor tasks. Methods Sixty four channels of electroencephalogram (EEG) and 10 channels of electromyogram (EMG) data were recorded from 10 neurologically-intact volunteers while they performed active and passive (no effort) pedaling on a custom-designed stationary bicycle. Ensemble averaged waveforms, 2 dimensional topographic maps and amplitude of the β (13–35 Hz) frequency band were analyzed and compared between active and passive trials. Results The peak-to-peak amplitude (peak positive–peak negative) of the EEG waveform recorded at the Cz electrode was higher in the passive than the active trials (p < 0.01). β-band oscillations in electrodes overlying the leg representation area of the cortex were significantly desynchronized during active compared to the passive pedaling (p < 0.01). A significant negative correlation was observed between the average EEG waveform for active trials and the composite EMG (summated EMG from both limbs for each muscle) of the rectus femoris (r = −0.77, p < 0.01) the medial hamstrings (r = −0.85, p < 0.01) and the tibialis anterior (r = −0.70, p < 0.01) muscles. Conclusions These results demonstrated that substantial sensorimotor processing occurs in the brain during pedaling in humans. Further, cortical activity seemed to be greatest during recruitment of the muscles critical for transitioning the legs from flexion to extension and vice versa. Significance This is the first study demonstrating the feasibility of EEG recording during pedaling, and owing to similarities between pedaling and bipedal walking, may provide valuable insight into brain activity during locomotion in humans. PMID:23036179

Work and power outputs determined from pedalling and flywheel friction forces during brief maximal exertion on a cycle ergometer.

PubMed

Hibi, N; Fujinaga, H; Ishii, K

1996-01-01

Work and power outputs during short-term, maximal exertion on a friction loaded cycle ergometer are usually calculated from the friction force applied to the flywheel. The inertia of the flywheel is sometimes taken into consideration, but the effects of internal resistances and other factors have been ignored. The purpose of this study was to estimate their effects by comparing work or power output determined from the force exerted on the pedals (pedalling force) with work or power output determined from the friction force and the moment of inertia of the rotational parts. A group of 22 male college students accelerated a cycle ergometer as rapidly as possible for 3 s. The total work output determined from the pedalling force (TWp) was significantly greater than that calculated from the friction force and the moment of inertia (TWf). Power output determined from the pedalling force during each pedal stroke (SPp) was also significantly greater than that calculated from the friction force and the moment of inertia. Percentage difference (% diff), defined by % diff = ¿(TWp - TWf)/TWf¿ x 100, ranged from 16.8% to 49.3% with a mean value of 30.8 (SD 9.1)%. It was observed that % diff values were higher in subjects with greater TWp or greater maximal SPp. These results would indicate that internal resistances and other factors, such as the deformation of the chain and the vibrations of the entire system, may have significant effects on the measurements of work and power outputs. The effects appear to depend on the magnitudes of pedalling force and pedal velocity.

The Reliability of Pedalling Rates Employed in Work Tests on the Bicycle Ergometer.

ERIC Educational Resources Information Center

Bolonchuk, W. W.

The purpose of this study was to determine whether a group of volunteer subjects could produce and maintain a pedalling cadence within an acceptable range of error. This, in turn, would aid in determining the reliability of pedalling rates employed in work tests on the bicycle ergometer. Forty male college students were randomly given four…

Neuro-mechanics of muscle coordination during recumbent pedaling in post-acute stroke patients.

PubMed

De Marchis, C; Ambrosini, E; Schmid, M; Monticone, M; Pedrocchi, A; Ferrigno, G; D'Alessio, T; Conforto, S; Ferrante, S

2015-01-01

Motor impairment after stroke has been hypothesized to be related, among others, to impairments in the modular control of movement. In this study we analyzed muscle coordination and pedal forces during a recumbent pedaling exercise from a sample of post-acute stroke patients (n=5) and a population of age-matched healthy individuals (n=4). Healthy subjects and the less impaired patients showed a shared modular organization of pedaling based on 4 similar muscle synergies. The most impaired patient, characterized by a Motricity Index of 52/100, showed a reduced complexity (only 2 muscle synergies for the affected side). Differences between healthy subjects and post-stroke patients in the execution of the task were identified in terms of unbalance in mechanical work production, which well corresponded to the level of impairment. This pedaling unbalance could be traced back to different activation strategies of the 4 identified modules. Investigation on a more representative sample will provide a full characterization of the neuro-mechanics of pedaling after stroke, helping our understandings of the disruption of motor coordination at central level after stroke and of the most effective solutions for functional recovery.

Feasibility of a portable pedal exercise machine for reducing sedentary time in the workplace.

PubMed

Carr, Lucas J; Walaska, Kristen A; Marcus, Bess H

2012-05-01

Sedentary time is independently associated with an increased risk of metabolic disease. Worksite interventions designed to decrease sedentary time may serve to improve employee health. The purpose of this study is to test the feasibility and use of a pedal exercise machine for reducing workplace sedentary time. Eighteen full-time employees (mean age+SD 40.2+10.7 years; 88% female) working in sedentary occupations were recruited for participation. Demographic and anthropometric data were collected at baseline and 4 weeks. Participants were provided access to a pedal exercise machine for 4 weeks at work. Use of the device was measured objectively by exercise tracking software, which monitors pedal activity and provides the user real-time feedback (eg, speed, time, distance, calories). At 4 weeks, participants completed a feasibility questionnaire. Participants reported sitting 83% of their working days. Participants used the pedal machines an average of 12.2+6.6 out of a possible 20 working days and pedalled an average of 23.4+20.4 min each day used. Feasibility data indicate that participants found the machines feasible for use at work. Participants also reported sedentary time at work decreased due to the machine. Findings from this study suggest that this pedal machine may be a feasible tool for reducing sedentary time while at work. These findings hold public health significance due to the growing number of sedentary jobs in the USA and the potential of the device for use in large-scale worksite health programmes.

Foot force direction control during a pedaling task in individuals post-stroke

PubMed Central

2014-01-01

Background Appropriate magnitude and directional control of foot-forces is required for successful execution of locomotor tasks. Earlier evidence suggested, following stroke, there is a potential impairment in foot-force control capabilities both during stationary force generation and locomotion. The purpose of this study was to investigate the foot-pedal surface interaction force components, in non-neurologically-impaired and stroke-impaired individuals, in order to determine how fore/aft shear-directed foot/pedal forces are controlled. Methods Sixteen individuals with chronic post-stroke hemiplegia and 10 age-similar non-neurologically-impaired controls performed a foot placement maintenance task under a stationary and a pedaling condition, achieving a target normal pedal force. Electromyography and force profiles were recorded. We expected generation of unduly large magnitude shear pedal forces and reduced participation of multiple muscles that can contribute forces in appropriate directions in individuals post-stroke. Results We found lower force output, inconsistent modulation of muscle activity and reduced ability to change foot force direction in the paretic limbs, but we did not observe unduly large magnitude shear pedal surface forces by the paretic limbs as we hypothesized. Conclusion These findings suggested the preservation of foot-force control capabilities post-stroke under minimal upright postural control requirements. Further research must be conducted to determine whether inappropriate shear force generation will be revealed under non-seated, postural demanding conditions, where subjects have to actively control for upright body suspension. PMID:24739234

Biomechanical Evaluation of an Electric Power-Assisted Bicycle by a Musculoskeletal Model

NASA Astrophysics Data System (ADS)

Takehara, Shoichiro; Murakami, Musashi; Hase, Kazunori

In this study, we construct an evaluation system for the muscular activity of the lower limbs when a human pedals an electric power-assisted bicycle. The evaluation system is composed of an electric power-assisted bicycle, a numerical simulator and a motion capture system. The electric power-assisted bicycle in this study has a pedal with an attached force sensor. The numerical simulator for pedaling motion is a musculoskeletal model of a human. The motion capture system measures the joint angles of the lower limb. We examine the influence of the electric power-assisted force on each muscle of the human trunk and legs. First, an experiment of pedaling motion is performed. Then, the musculoskeletal model is calculated by using the experimental data. We discuss the influence on each muscle by electric power-assist. It is found that the muscular activity is decreased by the electric power-assist bicycle, and the reduction of the muscular force required for pedaling motion was quantitatively shown for every muscle.

Ergometer

NASA Technical Reports Server (NTRS)

Gause, R. L.; Bynum, B. G. (Inventor)

1973-01-01

An ergometer is described that has a pedal driven direct current motor as a load and includes a frame for supporting the body of a person in either a sitting or a prone position. The pedals may be operated by either the feet or the hands. The electrical circuitry of the ergometer includes means for limiting the load applied to the pedals as a function of work being performed, heart rate, and increases in heart rate.

Multi-pedal DNA walker biosensors based on catalyzed hairpin assembly and isothermal strand-displacement polymerase reaction for the chemiluminescent detection of proteins.

PubMed

Li, Ningxing; Du, Mingyuan; Liu, Yucheng; Ji, Xinghu; He, Zhike

2018-06-25

Two kinds of sensitive biosensors based on multi-pedal DNA walker along a 3-D DNA functional magnet particles track for the chemiluminescent detection of streptavidin are constructed and compared in this study. In the presence of SA, multi-pedal DNA walker has been constructed by biotin-modified catalyst as a result of the terminal protection for avoiding the digestion by exonuclease I. Then a toehold of CHA-H1 conjugated with magnetic microparticles (MMPs) could interact with a 'leg' of multi-pedal DNA walker to open the hairpin via toehold-mediated strand exchange catalysis. A newly exposed DNA segment in CHA-H1 would be hybridized with a toehold of biotin-labeled H2. Via the strand displacement process, H2 displaces one 'leg' of multi-pedal DNA walker, and the other 'leg' could still hybridize with neighboring H1 to initiate the next cycle. In order to solve the high background caused by the hybridization between CHA-H1 and H2 without CHA-catalyst, the other model has been designed. The principle of the other model (ISDPR DNA walker) is similar to the above one. After the terminal protection of SA, a 'leg' of multi-pedal DNA walker triggers the opening of the hairpin of ISDPR-H1 conjugated with MMPs. Then the biotin-modified primer could hybridize with the open stem, triggering the polymerization reaction in the presence of dNTPs/polymerase. As the extension of the primer, the 'leg' of multi-pedal DNA walker is displaced so that the other 'leg' could trigger proximal H1 to go on the next cycle. Due to its lower background and stronger signal, multi-pedal DNA walker based on ISDPR has a lower limit of detection for SA. The limit of detection (LOD) for SA is 6.5 pM. What's more, these DNA walker methods have been applied in complex samples successfully.

A novel fMRI paradigm suggests that pedaling-related brain activation is altered after stroke

PubMed Central

Promjunyakul, Nutta-on; Schmit, Brian D.; Schindler-Ivens, Sheila M.

2015-01-01

The purpose of this study was to examine the feasibility of using functional magnetic resonance imaging (fMRI) to measure pedaling-related brain activation in individuals with stroke and age-matched controls. We also sought to identify stroke-related changes in brain activation associated with pedaling. Fourteen stroke and 12 control subjects were asked to pedal a custom, MRI-compatible device during fMRI. Subjects also performed lower limb tapping to localize brain regions involved in lower limb movement. All stroke and control subjects were able to pedal while positioned for fMRI. Two control subjects were withdrawn due to claustrophobia, and one control data set was excluded from analysis due to an incidental finding. In the stroke group, one subject was unable to enter the gantry due to excess adiposity, and one stroke data set was excluded from analysis due to excessive head motion. Consequently, 81% of subjects (12/14 stroke, 9/12 control) completed all procedures and provided valid pedaling-related fMRI data. In these subjects, head motion was ≤3 mm. In both groups, brain activation localized to the medial aspect of M1, S1, and Brodmann’s area 6 (BA6) and to the cerebellum (vermis, lobules IV, V, VIII). The location of brain activation was consistent with leg areas. Pedaling-related brain activation was apparent on both sides of the brain, with values for laterality index (LI) of –0.06 (0.20) in the stroke cortex, 0.05 (±0.06) in the control cortex, 0.29 (0.33) in the stroke cerebellum, and 0.04 (0.15) in the control cerebellum. In the stroke group, activation in the cerebellum – but not cortex – was significantly lateralized toward the damaged side of the brain (p = 0.01). The volume of pedaling-related brain activation was smaller in stroke as compared to control subjects. Differences reached statistical significance when all active regions were examined together [p = 0.03; 27,694 (9,608) μL stroke; 37,819 (9,169) μL control]. When individual regions were examined separately, reduced brain activation volume reached statistical significance in BA6 [p = 0.04; 4,350 (2,347) μL stroke; 6,938 (3,134) μL control] and cerebellum [p = 0.001; 4,591 (1,757) μL stroke; 8,381 (2,835) μL control]. Regardless of whether activated regions were examined together or separately, there were no significant between-group differences in brain activation intensity [p = 0.17; 1.30 (0.25)% stroke; 1.16 (0.20)% control]. Reduced volume in the stroke group was not observed during lower limb tapping and could not be fully attributed to differences in head motion or movement rate. There was a tendency for pedaling-related brain activation volume to increase with increasing work performed by the paretic limb during pedaling (p = 0.08, r = 0.525). Hence, the results of this study provide two original and important contributions. First, we demonstrated that pedaling can be used with fMRI to examine brain activation associated with lower limb movement in people with stroke. Unlike previous lower limb movements examined with fMRI, pedaling involves continuous, reciprocal, multijoint movement of both limbs. In this respect, pedaling has many characteristics of functional lower limb movements, such as walking. Thus, the importance of our contribution lies in the establishment of a novel paradigm that can be used to understand how the brain adapts to stroke to produce functional lower limb movements. Second, preliminary observations suggest that brain activation volume is reduced during pedaling post-stroke. Reduced brain activation volume may be due to anatomic, physiology, and/or behavioral differences between groups, but methodological issues cannot be excluded. Importantly, brain action volume post-stroke was both task-dependent and mutable, which suggests that it could be modified through rehabilitation. Future work will explore these possibilities. PMID:26089789

Initial, Cockpit Anthropometric Assessment of U.S. Navy T-6 Life Support Equipment

DTIC Science & Technology

2007-11-05

DEP was not specified. Zone 1, 2, and 3 reach conditions to controls and pedals and clearances were in accordance with military standard...functional leg reach as operation of pedals ; cockpit volume clearances, including ejection clearances not striking objects unintention-ally; and overhead...was measured from knee to any obstruction. Reach to pedals was measured from a position where full control was achieved. Arm reach was measured for

Plantar pressure of clipless and toe-clipped pedals in cyclists - A pilot study

PubMed Central

Davis, Andrea; Pemberton, Troy; Ghosh, Subhajit; Maffulli, Nicola; Padhiar, Nat

2011-01-01

Summary To determine the effect of clipless and toe-clipped pedals on plantar foot pressure while cycling. Seven bikers and 11 healthy volunteers were tested on a Giant ATX Team mountain bike, Tekscan Clinical 5.24 F-scan® system with an inner sole pressure sensor, a Tacx Cycle force One Turbo Trainer and a Cateye Mity 8 computerized speedometer were used. The subjects wore Shimano M037 shoes and used a standard clipless and toe-clipped pedal. The seat height was set at 100% of subject’s trochanteric height. Plantar pressures were recorded over 12 consecutive crank cycles at a constant speed for each of the power outputs. The videos were analysed to record the pressure exerted at 12 positions on the foot for each variable. Whether there is any dominance of any of the metatarsals, and any difference in plantar pressures between clipped and clipless pedal. There was a significant difference in the pressure at many positions of the foot, but the sites were different for each individual. General regression analysis indicated that pedal type had a statistically significant effect on plantar pressure at the sites of 1st metatarsal (p=0.042), 3rd metatarsal (p<0.001), 5th metatarsal (<0.001), 2nd (p=0.018) and 5th toe (p<0.001), lateral midfoot (p<0.001) and central heel (p<0.001) areas. Clipless pedals produce higher pressures which are more spread across the foot than toe-clipped pedals. This may have implications for their use in the prevention and/or management of overuse injuries in the knee and foot. PMID:23738240

Fully automatic control of paraplegic FES pedaling using higher-order sliding mode and fuzzy logic control.

PubMed

Farhoud, Aidin; Erfanian, Abbas

2014-05-01

In this paper, a fully automatic robust control strategy is proposed for control of paraplegic pedaling using functional electrical stimulation (FES). The method is based on higher-order sliding mode (HOSM) control and fuzzy logic control. In FES, the strength of muscle contraction can be altered either by varying the pulse width (PW) or by the pulse amplitude (PA) of the stimulation signal. The proposed control strategy regulates simultaneously both PA and PW (i.e., PA/PW modulation). A HOSM controller is designed for regulating the PW and a fuzzy logic controller for the PA. The proposed control scheme is free-model and does not require any offline training phase and subject-specific information. Simulation studies on a virtual patient and experiments on three paraplegic subjects demonstrate good tracking performance and robustness of the proposed control strategy against muscle fatigue and external disturbances during FES-induced pedaling. The results of simulation studies show that the power and cadence tracking errors are 5.4% and 4.8%, respectively. The experimental results indicate that the proposed controller can improve pedaling system efficacy and increase the endurance of FES pedaling. The average of power tracking error over three paraplegic subjects is 7.4±1.4% using PA/PW modulation, while the tracking error is 10.2±1.2% when PW modulation is used. The subjects could pedal for 15 min with about 4.1% power loss at the end of experiment using proposed control strategy, while the power loss is 14.3% using PW modulation. The controller could adjust the stimulation intensity to compensate the muscle fatigue during long period of FES pedaling.

Effect of pedal rate on primary and slow-component oxygen uptake responses during heavy-cycle exercise.

PubMed

Pringle, Jamie S M; Doust, Jonathan H; Carter, Helen; Tolfrey, Keith; Jones, Andrew M

2003-04-01

We hypothesized that a higher pedal rate (assumed to result in a greater proportional contribution of type II motor units) would be associated with an increased amplitude of the O(2) uptake (Vo(2)) slow component during heavy-cycle exercise. Ten subjects (mean +/- SD, age 26 +/- 4 yr, body mass 71.5 +/- 7.9 kg) completed a series of square-wave transitions to heavy exercise at pedal rates of 35, 75, and 115 rpm. The exercise power output was set at 50% of the difference between the pedal rate-specific ventilatory threshold and peak Vo(2), and the baseline power output was adjusted to account for differences in the O(2) cost of unloaded pedaling. The gain of the Vo(2) primary component was significantly higher at 35 rpm compared with 75 and 115 rpm (mean +/- SE, 10.6 +/- 0.3, 9.5 +/- 0.2, and 8.9 +/- 0.4 ml. min(-1). W(-1), respectively; P < 0.05). The amplitude of the Vo(2) slow component was significantly greater at 115 rpm (328 +/- 29 ml/min) compared with 35 rpm (109 +/- 30 ml/min) and 75 rpm (202 +/- 38 ml/min) (P < 0.05). There were no significant differences in the time constants or time delays associated with the primary and slow components across the pedal rates. The change in blood lactate concentration was significantly greater at 115 rpm (3.7 +/- 0.2 mM) and 75 rpm (2.8 +/- 0.3 mM) compared with 35 rpm (1.7 +/- 0.4 mM) (P < 0.05). These data indicate that pedal rate influences Vo(2) kinetics during heavy exercise at the same relative intensity, presumably by altering motor unit recruitment patterns.

Effects of a Non-Circular Chainring on Sprint Performance During a Cycle Ergometer Test

PubMed Central

Hintzy, Frédérique; Grappe, Frédéric; Belli, Alain

2016-01-01

Non-circular chainrings have been reported to alter the crank angular velocity profile over a pedal revolution so that more time is spent in the effective power phase. The purpose of this study was to determine whether sprint cycling performance could be improved using a non-circular chainring (Osymetric: ellipticity 1.25 and crank lever mounted nearly perpendicular to the major axis), in comparison with a circular chainring. Twenty sprint cyclists performed an 8 s sprint on a cycle ergometer against a 0.5 N/kg-1 friction force in four crossing conditions (non-circular or circular chainring with or without clipless pedal). Instantaneous force, velocity and power were continuously measured during each sprint. Three main characteristic pedal downstrokes were selected: maximal force (in the beginning of the sprint), maximal power (towards the middle), and maximal velocity (at the end of the sprint). Both average and instantaneous force, velocity and power were calculated during the three selected pedal downstrokes. The important finding of this study was that the maximal power output was significantly higher (+ 4.3%, p < 0.05) when using the non-circular chainring independent from the shoe-pedal linkage condition. This improvement is mainly explained by a significantly higher instantaneous external force that occurs during the downstroke. Non-circular chainring can have potential benefits on sprint cycling performance. Key points The Osymetric non-circular chainring significantly maximized crank power by 4.3% during sprint cycling, in comparison with a circular chainring. This maximal power output improvement was due to significant higher force developed when the crank was in the effective power phase. This maximal power output improvement was independent from the shoe-pedal linkage condition. Present benefits provided by the non-circular chainring on pedalling kinetics occurred only at high cadences. PMID:27274658

Value of the pinnal-pedal reflex in the diagnosis of canine scabies.

PubMed

Mueller, R S; Bettenay, S V; Shipstone, M

2001-05-19

The potential value of the pinnal-pedal scratch reflex as an aid to diagnosing canine scabies was assessed in 588 dogs with skin disease. The reflex was assessed by vigorously rubbing the tip of one earflap on to the base of the ear for five seconds, and it was considered positive if the ipsilateral hind leg made a scratching movement. A diagnosis of scabies was based on the dog's history, a physical examination and either positive skin scrapings or the complete resolution of pruritus and dermatitis after treatment with ivermectin or milbemycin, with no relapse for at least 12 months. Scabies was diagnosed in 55 of the dogs, allergic skin disease in 463, and 70 had other miscellaneous skin diseases. There was a positive pinnal-pedal scratch reflex in 45 (82 per cent) of the 55 dogs with scabies. Forty (73 per cent) of the dogs with scabies had pinnal dermatitis, and 36 (90 per cent) of these had a positive pinnal-pedal scratch reflex. There was a positive pinnal-pedal scratch reflex in 33 (6.2 per cent) of the other 533 dogs. On the basis of these results, the specificity of testing for scabies by the pinnal-pedal scratch reflex was 93.8 per cent, and the sensitivity was 81.8 per cent The test's positive predictive value was 0.57 and its negative predictive value was 0.98.

Bilateral pedaling asymmetry during a simulated 40-km cycling time-trial.

PubMed

Carpes, F P; Rossato, M; Faria, I E; Bolli Mota, C

2007-03-01

This study investigated the pedaling asymmetry during a 40-km cycling time-trial (TT). Six sub-elite competitive male cyclists pedaled a SRM Training Systems cycle ergometer throughout a simulated 40-km TT. A SRM scientific crank dynamometer was used to measure the bilateral crank torque (N.m) and pedaling cadence (rpm). All data were analyzed into 4 stages with equal length obtained according to total time. Comparisons between each stage of the 40-km TT were made by an analysis of variance (ANOVA). Dominant (DO) and non-dominant (ND) crank peak torque asymmetry was determined by the equation: asymmetry index (AI%)=[(DO-ND)/DO] 100. Pearson correlation analysis was performed to verify the relationship between exercise intensity, mean and crank peak torque. The crank peak torque was significantly (P<0.05) greater in the 4th stage compared with other stages. During the stages 2 and 3, was observed the AI% of 13.51% and 17.28%, respectively. Exercise intensity (%VO(2max)) was greater for stage 4 (P<0.05) and was highly correlated with mean and crank peak torque (r=0.97 and r=0.92, respectively) for each stage. The DO limb was always responsible for the larger crank peak torque. It was concluded that pedaling asymmetry is present during a simulated 40-km TT and an increase on crank torque output and exercise intensity elicits a reduction in pedaling asymmetry.

Noncircular Chainrings Do Not Influence Maximum Cycling Power.

PubMed

Leong, Chee-Hoi; Elmer, Steven J; Martin, James C

2017-12-01

Noncircular chainrings could increase cycling power by prolonging the powerful leg extension/flexion phases, and curtailing the low-power transition phases. We compared maximal cycling power-pedaling rate relationships, and joint-specific kinematics and powers across 3 chainring eccentricities (CON = 1.0; LOW ecc  = 1.13; HIGH ecc  = 1.24). Part I: Thirteen cyclists performed maximal inertial-load cycling under 3 chainring conditions. Maximum cycling power and optimal pedaling rate were determined. Part II: Ten cyclists performed maximal isokinetic cycling (120 rpm) under the same 3 chainring conditions. Pedal and joint-specific powers were determined using pedal forces and limb kinematics. Neither maximal cycling power nor optimal pedaling rate differed across chainring conditions (all p > .05). Peak ankle angular velocity for HIGH ecc was less than CON (p < .05), while knee and hip angular velocities were unaffected. Self-selected ankle joint-center trajectory was more eccentric than HIGH ecc with an opposite orientation that increased velocity during extension/flexion and reduced velocity during transitions. Joint-specific powers did not differ across chainring conditions, with a small increase in power absorbed during ankle dorsiflexion with HIGH ecc . Multiple degrees of freedom in the leg, crank, and pedal system allowed cyclists to manipulate ankle angular velocity to maintain their preferred knee and hip actions, suggesting maximizing extension/flexion and minimizing transition phases may be counterproductive for maximal power.

Interindividual variability of electromyographic patterns and pedal force profiles in trained cyclists.

PubMed

Hug, François; Drouet, Jean Marc; Champoux, Yvan; Couturier, Antoine; Dorel, Sylvain

2008-11-01

The aim of this study was to determine whether high inter-individual variability of the electromyographic (EMG) patterns during pedaling is accompanied by variability in the pedal force application patterns. Eleven male experienced cyclists were tested at two submaximal power outputs (150 and 250 W). Pedal force components (effective and total forces) and index of mechanical effectiveness were measured continuously using instrumented pedals and were synchronized with surface electromyography signals measured in ten lower limb muscles. The intersubject variability of EMG and mechanical patterns was assessed using standard deviation, mean deviation, variance ratio and coefficient of cross-correlation (_R(0), with lag time = 0). The results demonstrated a high intersubject variability of EMG patterns at both exercise intensities for biarticular muscles as a whole (and especially for Gastrocnemius lateralis and Rectus femoris) and for one monoarticular muscle (Tibialis anterior). However, this heterogeneity of EMG patterns is not accompanied by a so high intersubject variability in pedal force application patterns. A very low variability in the three mechanical profiles (effective force, total force and index of mechanical effectiveness) was obtained in the propulsive downstroke phase, although a greater variability in these mechanical patterns was found during upstroke and around the top dead center, and at 250 W when compared to 150 W. Overall, these results provide additional evidence for redundancy in the neuromuscular system.

Effect of pedal rate and power output on rating of perceived exertion during cycle ergometry exercise.

PubMed

Hamer, Mark; Boutcher, Yati N; Boutcher, Stephen H

2005-12-01

This study examined differentiated rating of perceived exertion (RPE), heart rate, and heart-rate variability during light cycle ergometry exercise at two different pedal rates. 30 healthy men (22.6 +/- 0.9 yr.) were recruited from a student population and completed a continuous 20-min. cycle ergometry exercise protocol, consisting of a 4-min. warm-up (60 rev./min., 30 Watts), followed by four bouts of 4 min. at different combinations of pedal rate (40 or 80 rev./min.) and power output (40 or 80 Watts). The order of the four combinations was counterbalanced across participants. Heart rate was measured using a polar heart-rate monitor, and parasympathetic balance was assessed through time series analysis of heart-rate variability. Measures were compared using a 2 (pedal rate) x 2 (power output) repeated-measures analysis of variance. RPE was significantly greater (p<.05) at 80 versus 40 rev./min. at 40 W. For both power outputs heart rate was significantly increased, and the high frequency component of heart-rate variability was significantly reduced at 80 compared with 40 rev./min. These findings indicate the RPE was greater at higher than at lower pedalling rates for a light absolute power output which contrasts with previous findings based on use of higher power output. Also, pedal rate had a significant effect on heart rate and heart-rate variability at constant power output.

Perception of Stand-on-ability: Do Geographical Slants Feel Steeper Than They Look?

PubMed

Hajnal, Alen; Wagman, Jeffrey B; Doyon, Jonathan K; Clark, Joseph D

2016-07-01

Past research has shown that haptically perceived surface slant by foot is matched with visually perceived slant by a factor of 0.81. Slopes perceived visually appear shallower than when stood on without looking. We sought to identify the sources of this discrepancy by asking participants to judge whether they would be able to stand on an inclined ramp. In the first experiment, visual perception was compared to pedal perception in which participants took half a step with one foot onto an occluded ramp. Visual perception closely matched the actual maximal slope angle that one could stand on, whereas pedal perception underestimated it. Participants may have been less stable in the pedal condition while taking half a step onto the ramp. We controlled for this by having participants hold onto a sturdy tripod in the pedal condition (Experiment 2). This did not eliminate the difference between visual and haptic perception, but repeating the task while sitting on a chair did (Experiment 3). Beyond balance requirements, pedal perception may also be constrained by the limited range of motion at the ankle and knee joints while standing. Indeed, when we restricted range of motion by wearing an ankle brace pedal perception underestimated the affordance (Experiment 4). Implications for ecological theory were offered by discussing the notion of functional equivalence and the role of exploration in perception. © The Author(s) 2016.

Pedal force determination respect to ride comfort

NASA Astrophysics Data System (ADS)

Mačužić, Slavica; Lukić, Jovanka; Glišović, Jasna; Miloradović, Danijela

2017-10-01

Automotive ergonomics is a set of knowledge which has a task to design a vehicle to make the passengers feel comfortable. Interior packaging represents an important stage in the vehicle design process, in order to enable the driver to every important aspect of movement. During the process of driving, the driver performs various movements of arms and legs, leading to a certain fatigue. Each seating position in the vehicle, contain certain boundary conditions, and for that reason it was necessary to examine how the seating position affects the driver possibilities. In this paper, the pedal forces were determined by application of Ramsis human model. Different human populations were taken into account. Correlation between subjects’ anthropometrics measures and the foot pedal force pedal was observed. Obtained results were significant input data for vehicle packaging.

Foot Pedals for Spacecraft Manual Control

NASA Technical Reports Server (NTRS)

Love, Stanley G.; Morin, Lee M.; McCabe, Mary

2010-01-01

Fifty years ago, NASA decided that the cockpit controls in spacecraft should be like the ones in airplanes. But controls based on the stick and rudder may not be best way to manually control a vehicle in space. A different method is based on submersible vehicles controlled with foot pedals. A new pilot can learn the sub's control scheme in minutes and drive it hands-free. We are building a pair of foot pedals for spacecraft control, and will test them in a spacecraft flight simulator.

Development of a Nonlinear 6-Degree of Freedom Miniature Rotary-Wing Unmanned Aerial Vehicle Software Model and PID Flight Path Controller Using MathWorks Simulink Simulation Environment

DTIC Science & Technology

2009-09-01

the cyclic behavior of the rotor angle of attack. The last form of pilot command is the rudder pedal . The rudder pedal provides collective input...response of [1, p. 112], as expected. The yaw angle increases in a counter-clockwise direction with right pedal input and damps down to almost zero yaw...FORCES.........................................................................45 1. Determination of Drag and Main Rotor Tip-Path Plane Angle ....45

MANPRINT Evaluation of the High Mobility Multipurpose Wheeled Vehicle-Heavy Variant (HMMWV-HV)

DTIC Science & Technology

1990-02-01

gap between brake and gas pedal . Knee hits throttle control. Metal below seat hits back of calf muscle. Visibility Is the driver’s visibility adequate...24, No - 0, NA - 0] Gas pedal : 79. Parked? [Yes - 24, No - 0, NA - 0] 80. Primary and Secondary roads? [Yes - 24, No - 0, NA - 0] 81. Cross-country...Yes - 24, No - 0, NA - 0] 89 Brake pedal : 82. Parked? [Yes - 24, No - 0, NA - 0] 83. Primary and Secondary roads? [Yes - 24, No - 0, NA - 0] 84

Engineer pedals STS-37 CETA electrical cart along track in JSC MAIL Bldg 9A

NASA Technical Reports Server (NTRS)

1990-01-01

McDonnell Douglas engineer Gary Peters operates crew and equipment translation aid (CETA) electrical hand pedal cart in JSC's Mockup and Integration Laboratory (MAIL) Bldg 9A. Peters, wearing extravehicular mobility unit (EMU) boots and positioned in portable foot restraint (PFR), is suspended above CETA cart and track via harness to simulate weightlessness. The electrical cart is moved by electricity generated from turning hand pedals. CETA will be tested in orbit in the payload bay of Atlantis, Orbiter Vehicle (OV) 104, during STS-37.

Crank inertial load has little effect on steady-state pedaling coordination.

PubMed

Fregly, B J; Zajac, F E; Dairaghi, C A

1996-12-01

Inertial load can affect the control of a dynamic system whenever parts of the system are accelerated or decelerated. During steady-state pedaling, because within-cycle variations in crank angular acceleration still exist, the amount of crank inertia present (which varies widely with road-riding gear ratio) may affect the within-cycle coordination of muscles. However, the effect of inertial load on steady-state pedaling coordination is almost always assumed to be negligible, since the net mechanical energy per cycle developed by muscles only depends on the constant cadence and workload. This study test the hypothesis that under steady-state conditions, the net joint torques produced by muscles at the hip, knee, and ankle are unaffected by crank inertial load. To perform the investigation, we constructed a pedaling apparatus which could emulate the low inertial load of a standard ergometer or the high inertial load of a road bicycle in high gear. Crank angle and bilateral pedal force and angle data were collected from ten subjects instructed to pedal steadily (i.e., constant speed across cycles) and smoothly (i.e., constant speed within a cycle) against both inertias at a constant workload. Virtually no statistically significant changes were found in the net hip and knee muscle joint torques calculated from an inverse dynamics analysis. Though the net ankle muscle joint torque, as well as the one- and two-legged crank torque, showed statistically significant increases at the higher inertia, the changes were small. In contrast, large statistically significant reductions were found in crank kinematic variability both within a cycle and between cycles (i.e., cadence), primarily because a larger inertial load means a slower crank dynamic response. Nonetheless, the reduction in cadence variability was somewhat attenuated by a large statistically significant increase in one-legged crank torque variability. We suggest, therefore, that muscle coordination during steady-state pedaling is largely unaffected, though less well regulated, when crank inertial load is increased.

Older drivers' foot movements : traffic tech.

DOT National Transportation Integrated Search

2017-07-01

This study explored how older drivers use their accelerator and : brake pedals, to identify characteristics that could pose an increased : risk of a pedal application error. The study also explored whether : driver-vehicle fit was related to these ch...

ISG hybrid powertrain: a rule-based driver model incorporating look-ahead information

NASA Astrophysics Data System (ADS)

Shen, Shuiwen; Zhang, Junzhi; Chen, Xiaojiang; Zhong, Qing-Chang; Thornton, Roger

2010-03-01

According to European regulations, if the amount of regenerative braking is determined by the travel of the brake pedal, more stringent standards must be applied, otherwise it may adversely affect the existing vehicle safety system. The use of engine or vehicle speed to derive regenerative braking is one way to avoid strict design standards, but this introduces discontinuity in powertrain torque when the driver releases the acceleration pedal or applies the brake pedal. This is shown to cause oscillations in the pedal input and powertrain torque when a conventional driver model is adopted. Look-ahead information, together with other predicted vehicle states, are adopted to control the vehicle speed, in particular, during deceleration, and to improve the driver model so that oscillations can be avoided. The improved driver model makes analysis and validation of the control strategy for an integrated starter generator (ISG) hybrid powertrain possible.

Differences in Pedaling Technique in Cycling: A Cluster Analysis.

PubMed

Lanferdini, Fábio J; Bini, Rodrigo R; Figueiredo, Pedro; Diefenthaeler, Fernando; Mota, Carlos B; Arndt, Anton; Vaz, Marco A

2016-10-01

To employ cluster analysis to assess if cyclists would opt for different strategies in terms of neuromuscular patterns when pedaling at the power output of their second ventilatory threshold (PO VT2 ) compared with cycling at their maximal power output (PO MAX ). Twenty athletes performed an incremental cycling test to determine their power output (PO MAX and PO VT2 ; first session), and pedal forces, muscle activation, muscle-tendon unit length, and vastus lateralis architecture (fascicle length, pennation angle, and muscle thickness) were recorded (second session) in PO MAX and PO VT2 . Athletes were assigned to 2 clusters based on the behavior of outcome variables at PO VT2 and PO MAX using cluster analysis. Clusters 1 (n = 14) and 2 (n = 6) showed similar power output and oxygen uptake. Cluster 1 presented larger increases in pedal force and knee power than cluster 2, without differences for the index of effectiveness. Cluster 1 presented less variation in knee angle, muscle-tendon unit length, pennation angle, and tendon length than cluster 2. However, clusters 1 and 2 showed similar muscle thickness, fascicle length, and muscle activation. When cycling at PO VT2 vs PO MAX , cyclists could opt for keeping a constant knee power and pedal-force production, associated with an increase in tendon excursion and a constant fascicle length. Increases in power output lead to greater variations in knee angle, muscle-tendon unit length, tendon length, and pennation angle of vastus lateralis for a similar knee-extensor activation and smaller pedal-force changes in cyclists from cluster 2 than in cluster 1.

Differences in pedal forces during recumbent cycling in adolescents with and without cerebral palsy

PubMed Central

Johnston, Therese E.; Prosser, Laura A.; Lee, Samuel C.K.

2011-01-01

Background We showed that subjects with cerebral palsy had greater transverse and frontal plane hip and knee motion, increased duration of muscle activity, increased cocontraction, and decreased efficiency during recumbent cycling than subjects with typical development. However, it is also important to understand the forces exerted on the pedals. The purpose of this report was to compare pedal forces during cycling between adolescents with and without cerebral palsy. Methods Ten subjects (3 male, 7 female) with spastic diplegic or quadriplegic cerebral palsy (15.6 years, SD 1.8) and 10 subjects (3 male, 7 female) with typical development (14.9 years, SD 1.4) cycled on a stationary recumbent cycle at 30 and 60 revolutions per minute if able. Three-dimensional piezoelectric force transducers measured pedal forces. Data were analyzed using two-way ANOVAs. Findings Subjects with cerebral palsy spent a smaller percentage (P < .001, r2 = .09, power = 1.0) of the revolution applying positive force (pushing into the pedal during the extension phase) and a greater percentage (P < .001, r2 = .09, power = 1.0) of the revolution applying negative force (pulling away from the pedal during the flexion phase). There was no effect of cadence and no interaction effect. Interpretation These findings compliment our earlier findings of altered joint kinematics and muscle activity indicating that subjects with cerebral palsy and typical development have different cycling strategies. Methods to increase the duration of the positive force may allow subjects with CP to cycle more successfully and cycle vigorously enough to reach a heart rate necessary for improving fitness. PMID:17950505

The development of contact force construction in the dynamic-contact task of cycling [corrected].

PubMed

Brown, Nicholas A T; Jensen, Jody L

2003-01-01

Purposeful movement requires that an individual produce appropriate joint torques to accelerate segments, and when environmental contact is involved, to develop task-appropriate contact forces. Developmental research has been confined largely to the mastery of unconstrained movement skills (pointing, kicking). The purpose of this study was to study the developmental progression that characterizes the interaction of muscular and non-muscular forces in tasks constrained by contact with the environment. Seven younger children (YC, 6-8 years), 7 older children (OC, 9-11 years) and 7 adults (AD) pedaled an ergometer (80 rpm) at an anthropometrically scaled cycling power. Resultant forces measured at the pedal's surface were decomposed into muscle, inertia and gravity components. Muscle pedal forces were further examined in terms of the underlying lower extremity joint torques and kinematic weights that constitute the muscular component of the pedal force. Data showed children applied muscle forces to the pedal in a significantly different manner compared to adults, and that this was due to the children's lower segmental mass and inertia. The children adjusted the contribution of the proximal joint muscle torques to compensate for reduced contributions to the resultant pedal force by gravitational and inertial components. These data show that smaller segmental mass and inertia limit younger children's ability to construct the dynamic-contact task of cycling in an adult-like form. On the basis of these results, however, the children's response was not "immature". Rather, the results show a task-appropriate adaptation to lower segmental mass and inertia. Copyright 2002 Elsevier Science Ltd.

Symmetrical kinematics does not imply symmetrical kinetics in people with transtibial amputation using cycling model.

PubMed

Childers, W Lee; Kogler, Géza F

2014-01-01

People with amputation move asymmetrically with regard to kinematics (joint angles) and kinetics (joint forces and moments). Clinicians have traditionally sought to minimize kinematic asymmetries, assuming kinetic asymmetries would also be minimized. A cycling model evaluated locomotor asymmetries. Eight individuals with unilateral transtibial amputation pedaled with 172 mm-length crank arms on both sides (control condition) and with the crank arm length shortened to 162 mm on the amputated side (CRANK condition). Pedaling kinetics and limb kinematics were recorded. Joint kinetics, joint angles (mean and range of motion [ROM]), and pedaling asymmetries were calculated from force pedals and with a motion capture system. A one-way analysis of variance with tukey post hoc compared kinetics and kinematics across limbs. Statistical significance was set to p

Analysis of muscular activity and dynamic response of the lower limb adding vibration to cycling.

PubMed

Munera, Marcela; Bertucci, William; Duc, Sebastien; Chiementin, Xavier

2018-07-01

Vibration in cycling has been proved to have undesirable effects over health, comfort and performance of the rider. In this study, 15 participants performed eight 6-min sub-maximal pedalling exercises at a constant power output (150W) and pedalling cadence (80 RPM) being exposed to vibration at different frequencies (20, 30, 40, 50, 60, 70 Hz) or without vibration. Oxygen uptake (VO2), heart rate (HR), surface EMG activity of seven lower limb muscles (GMax, RF, BF, VM, GAS, SOL and TA) and 3-dimentional accelerations at ankle, knee and hip were measured during the exercises. To analyse the dynamic response, the influence of the pedalling movement was taken into account. The results show that there was not significant influence of vibrations on HR and VO2 during this pedalling exercise. However, muscular activity presents a significant increase with the presence of vibration that is influenced by the frequency, but this increase was very low (< 1%). Also, the dynamic response shows an influence of the frequency as well as an influence of the different parts of the pedalling cycle. Those results help to explain the effects of vibration on the human body and the influence of the rider/bike interaction in those effects.

Spool-shaped proximal pedal phalanges.

PubMed

Sutro, C J; Sutro, W H

1986-01-01

We have observed that "spool-shaped" proximal pedal phalanges sometimes are found in single or multiple toes, often affecting both feet. These changes may be present in normal as well as abnormal feet. The etiology is unknown. Such changes do not occur in the hands.

Changes in Muscle and Joint Coordination in Learning to Direct Forces

PubMed Central

Hasson, Christopher J.; Caldwell, Graham E.; van Emmerik, Richard E.A.

2008-01-01

While it has been suggested that biarticular muscles have a specialized role in directing external reaction forces, it is unclear how humans learn to coordinate mono- and bi-articular muscles to perform force-directing tasks. Subjects were asked to direct pedal forces in a specified target direction during one-legged cycling. We expected that with practice, performance improvement would be associated with specific changes in joint torque patterns and mono- and bi-articular muscular coordination. Nine male subjects practiced pedaling an ergometer with only their left leg, and were instructed to always direct their applied pedal force perpendicular to the crank arm (target direction) and to maintain a constant pedaling speed. After a single practice session, the mean error between the applied and target pedal force directions decreased significantly. This improved performance was accompanied by a significant decrease in the amount of ankle angular motion and a smaller increase in knee and hip angular motion. This coincided with a re-organization of lower extremity joint torques, with a decrease in ankle plantarflexor torque and an increase in knee and hip flexor torques. Changes were seen in both mono- and bi-articular muscle activity patterns. The monoarticular muscles exhibited greater alterations, and appeared to contribute to both mechanical work and force directing. With practice, a loosening of the coupling between biarticular thigh muscle activation and joint torque co-regulation was observed. The results demonstrated that subjects were able to learn a complex and dynamic force-directing task by changing the direction of their applied pedal forces through re-organization of joint torque patterns and mono- and bi-articular muscle coordination. PMID:18405988

Changes in muscle and joint coordination in learning to direct forces.

PubMed

Hasson, Christopher J; Caldwell, Graham E; van Emmerik, Richard E A

2008-08-01

While it has been suggested that bi-articular muscles have a specialized role in directing external reaction forces, it is unclear how humans learn to coordinate mono- and bi-articular muscles to perform force-directing tasks. Participants were asked to direct pedal forces in a specified target direction during one-legged cycling. We expected that with practice, performance improvement would be associated with specific changes in joint torque patterns and mono- and bi-articular muscular coordination. Nine male participants practiced pedaling an ergometer with only their left leg, and were instructed to always direct their applied pedal force perpendicular to the crank arm (target direction) and to maintain a constant pedaling speed. After a single practice session, the mean error between the applied and target pedal force directions decreased significantly. This improved performance was accompanied by a significant decrease in the amount of ankle angular motion and a smaller increase in knee and hip angular motion. This coincided with a re-organization of lower extremity joint torques, with a decrease in ankle plantarflexor torque and an increase in knee and hip flexor torques. Changes were seen in both mono- and bi-articular muscle activity patterns. The mono-articular muscles exhibited greater alterations, and appeared to contribute to both mechanical work and force-directing. With practice, a loosening of the coupling between bi-articular thigh muscle activation and joint torque co-regulation was observed. The results demonstrated that participants were able to learn a complex and dynamic force-directing task by changing the direction of their applied pedal forces through re-organization of joint torque patterns and mono- and bi-articular muscle coordination.

Pedal symphalangism in modern American and Japanese skeletons.

PubMed

Case, D T; Heilman, J

2005-01-01

Pedal symphalangism is a surprisingly common heritable trait of the human foot. In individuals exhibiting the trait, the joint between the intermediate and distal phalanges of one or more lateral toes never develops, resulting in toes with two phalanges rather than three. This study was undertaken to explore variation in the frequency of pedal symphalangism among groups with widely different geographic ancestry, and to consider the applicability of this trait to skeletal biological distance studies. A total of 460 Euro-American, 191 African-American and 99 Japanese skeletons were examined for presence of pedal symphalangism. The American individuals date to the first half of the 20th c, while the Japanese individuals date to the late 19th and early 20th c. Although the country of ancestry is unknown for most of the American individuals, the Euro-Americans appear to be largely northern European, with roots in Germany, Ireland and Scandinavia, while the African-Americans are primarily descendants of slaves with roots in west African countries such as Nigeria, Benin, Togo, Ghana and Sierra Leone. Frequencies of fifth toe pedal symphalangism were calculated and compared among all three samples and found to be significantly higher in modern Japanese (83.7%) than in either Euro-Americans (46.4%) or African-Americans (44.0%). The Euro- and African-American frequencies were statistically indistinguishable for symphalangism of the fifth toe. In the fourth toe, however, the opposite result was found. The African-American frequency (7.9%) was significantly higher than the Euro-American frequency (2.6%), while no difference was found between the African-Americans and Japanese (11.7%). Since fourth toe pedal symphalangism has never been observed in the absence of fifth toe involvement, some of the same genes are clearly involved in producing the trait in both toes. However, differences in the pattern of fourth and fifth toe expression among the three groups identified in this study suggest that additional genetic or developmental factors may play a role in expression of pedal symphalangism in each of the toes.

Alternative sensor system and MLP neural network for vehicle pedal activity estimation.

PubMed

Wefky, Ahmed M; Espinosa, Felipe; Jiménez, José A; Santiso, Enrique; Rodríguez, José M; Fernández, Alfredo J

2010-01-01

It is accepted that the activity of the vehicle pedals (i.e., throttle, brake, clutch) reflects the driver's behavior, which is at least partially related to the fuel consumption and vehicle pollutant emissions. This paper presents a solution to estimate the driver activity regardless of the type, model, and year of fabrication of the vehicle. The solution is based on an alternative sensor system (regime engine, vehicle speed, frontal inclination and linear acceleration) that reflects the activity of the pedals in an indirect way, to estimate that activity by means of a multilayer perceptron neural network with a single hidden layer.

Alternative Sensor System and MLP Neural Network for Vehicle Pedal Activity Estimation

PubMed Central

Wefky, Ahmed M.; Espinosa, Felipe; Jiménez, José A.; Santiso, Enrique; Rodríguez, José M.; Fernández, Alfredo J.

2010-01-01

It is accepted that the activity of the vehicle pedals (i.e., throttle, brake, clutch) reflects the driver’s behavior, which is at least partially related to the fuel consumption and vehicle pollutant emissions. This paper presents a solution to estimate the driver activity regardless of the type, model, and year of fabrication of the vehicle. The solution is based on an alternative sensor system (regime engine, vehicle speed, frontal inclination and linear acceleration) that reflects the activity of the pedals in an indirect way, to estimate that activity by means of a multilayer perceptron neural network with a single hidden layer. PMID:22319326

A novel biofeedback cycling training to improve gait symmetry in stroke patients: a case series study.

PubMed

Ambrosini, Emilia; Ferrante, Simona; Pedrocchi, Alessandra; Ferrigno, Giancarlo; Guanziroli, Eleonora; Molteni, Franco

2011-01-01

The restoration of walking ability is crucial for maximizing independent mobility among patients with stroke. Leg cycling is becoming an established intervention to supplement ambulation training for stroke patients with problems of unbalance and weakness. The aim of the study was to explore the feasibility of a biofeedback pedaling treatment and its effects on cycling and walking ability in chronic stroke patients. Three patients were included in the study. The training consisted of a 2-week treatment of 6 sessions, during which a visual biofeedback helped the participants in maintaining a symmetrical pedaling. Participants were assessed before, after training and at follow-up, by means of a pedaling test and gait analysis. Outcome measurements were the unbalance during pedaling, the temporal, spatial and symmetry parameters during walking. An intra-subject statistical analysis (ANOVA, p<;0.05) showed that all patients significantly decreased pedaling unbalance after treatment and maintained the improvements at follow-up. The training induced some gait pattern modifications in two patients: one significantly improved mean velocity and gait symmetry, while the other one reduced the compensation strategy of the healthy leg. The results demonstrated the feasibility of the treatment. If further trials on a larger and controlled scale confirmed the same results, this treatment, thanks to its safety and low price, could have a significant impact as a home-rehabilitation treatment. © 2011 IEEE

Differences in pedalling technique between road cyclists of different competitive levels.

PubMed

García-López, Juan; Díez-Leal, Sergio; Ogueta-Alday, Ana; Larrazabal, Josu; Rodríguez-Marroyo, José A

2016-09-01

The purpose of this study was to compare the pedalling technique in road cyclists of different competitive levels. Eleven professional, thirteen elite and fourteen club cyclists were assessed at the beginning of their competition season. Cyclists' anthropometric characteristics and bike measurements were recorded. Three sets of pedalling (200, 250 and 300 W) on a cycle ergometer that simulated their habitual cycling posture were performed at a constant cadence (~90 rpm), while kinetic and kinematic variables were registered. The results showed no differences on the main anthropometric variables and bike measurements. Professional cyclists obtained higher positive impulse proportion (1.5-3.3% and P < 0.05), mainly due to a lower resistive torque during the upstroke (15.4-28.7% and P < 0.05). They also showed a higher ankle range of movement (ROM, 1.1-4.0° and P < 0.05). Significant correlations (P < 0.05) were found between the cyclists' body mass and the kinetic variables of pedalling: positive impulse proportion (r = -0.59 to -0.61), minimum (r = -0.59 to -0.63) and maximum torques (r = 0.35-0.47). In conclusion, professional cyclists had better pedalling technique than elite and club cyclists, because they opted for enhancing pulling force at the recovery phase to sustain the same power output. This technique depended on cycling experience and level of expertise.

Analysis of different image-based biofeedback models for improving cycling performances

NASA Astrophysics Data System (ADS)

Bibbo, D.; Conforto, S.; Bernabucci, I.; Carli, M.; Schmid, M.; D'Alessio, T.

2012-03-01

Sport practice can take advantage from the quantitative assessment of task execution, which is strictly connected to the implementation of optimized training procedures. To this aim, it is interesting to explore the effectiveness of biofeedback training techniques. This implies a complete chain for information extraction containing instrumented devices, processing algorithms and graphical user interfaces (GUIs) to extract valuable information (i.e. kinematics, dynamics, and electrophysiology) to be presented in real-time to the athlete. In cycling, performance indexes displayed in a simple and perceivable way can help the cyclist optimize the pedaling. To this purpose, in this study four different GUIs have been designed and used in order to understand if and how a graphical biofeedback can influence the cycling performance. In particular, information related to the mechanical efficiency of pedaling is represented in each of the designed interfaces and then displayed to the user. This index is real-time calculated on the basis of the force signals exerted on the pedals during cycling. Instrumented pedals for bikes, already designed and implemented in our laboratory, have been used to measure those force components. A group of subjects underwent an experimental protocol and pedaled with (the interfaces have been used in a randomized order) and without graphical biofeedback. Preliminary results show how the effective perception of the biofeedback influences the motor performance.

Pre-impact lower extremity posture and brake pedal force predict foot and ankle forces during an automobile collision.

PubMed

Hardin, E C; Su, A; van den Bogert, A J

2004-12-01

The purpose of this study was to determine how a driver's foot and ankle forces during a frontal vehicle collision depend on initial lower extremity posture and brake pedal force. A 2D musculoskeletal model with seven segments and six right-side muscle groups was used. A simulation of a three-second braking task found 3647 sets of muscle activation levels that resulted in stable braking postures with realistic pedal force. These activation patterns were then used in impact simulations where vehicle deceleration was applied and driver movements and foot and ankle forces were simulated. Peak rearfoot ground reaction force (F(RF)), peak Achilles tendon force (FAT), peak calcaneal force (F(CF)) and peak ankle joint force (F(AJ)) were calculated. Peak forces during the impact simulation were 476 +/- 687 N (F(RF)), 2934 +/- 944 N (F(CF)) and 2449 +/- 918 N (F(AJ)). Many simulations resulted in force levels that could cause fractures. Multivariate quadratic regression determined that the pre-impact brake pedal force (PF), knee angle (KA) and heel distance (HD) explained 72% of the variance in peak FRF, 62% in peak F(CF) and 73% in peak F(AJ). Foot and ankle forces during a collision depend on initial posture and pedal force. Braking postures with increased knee flexion, while keeping the seat position fixed, are associated with higher foot and ankle forces during a collision.

49 CFR 570.6 - Brake power unit.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 6 2010-10-01 2010-10-01 false Brake power unit. 570.6 Section 570.6... Pounds or Less § 570.6 Brake power unit. (a) Vacuum hoses shall not be collapsed, abraded, broken... brake pedal, the pedal shall fall slightly when the engine is started, demonstrating integrity of the...

PyPedal, an open source software package for pedigree analysis

USDA-ARS?s Scientific Manuscript database

The open source software package PyPedal (http://pypedal.sourceforge.net/) was first released in 2002, and provided users with a set of simple tools for manipulating pedigrees. Its flexibility has been demonstrated by its used in a number of settings for large and small populations. After substantia...

78 FR 52712 - Airworthiness Directives; Bombardier, Inc. Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-26

... prompted by reports of fractured rudder pedal tubes installed on the pilot-side rudder bar assembly. This... tubes, and replacement of affected pilot-side rudder bar assemblies if necessary. We are proposing this AD to detect and correct cracking of both pilot-side rudder pedal tubes, which could result in loss...

A Coordinated Control Architecture for Disaster Response Robots

DTIC Science & Technology

2016-01-01

to use these same algorithms to provide navigation Odometry for the vehicle motions when the robot is driving. Visual Odometry The YouTube link... depressed the accelerator pedal. We relied on the fact that the vehicle quickly comes to rest when the accelerator pedal is not being pressed. The

Undergraduates as Environmental Educators: The Pedal and Paddle Pollution Tour Experience

ERIC Educational Resources Information Center

Cronje, Ruth Johnson; Neff, Paula Kleintjes; Mowry, Donald; Running, Garry L.

2016-01-01

Undergraduates can become effective agents of environmental outreach when challenged to produce evidence-based messages to inform the public about local environmental issues. We recount our experience partnering our undergraduate students with community organizations dedicated to water stewardship to create a "Pedal and Paddle Pollution…

KSC-03pd0441

NASA Image and Video Library

2003-02-04

KENNEDY SPACE CENTER, FLA. - Shown are the Lander pedals for MER-1. These pedals fold up covering the Rover, which will be attached to the base pedal (not shown--empty spot in the center.) Set to launch in 2003, the MER Mission will consist of two identical rovers designed to cover roughly 110 yards each Martian day. Each rover will carry five scientific instruments that will allow it to search for evidence of liquid water that may have been present in the planet's past. The rovers will be identical to each other, but will land at different regions of Mars. The first rover has a launch window opening May 30, and the second rover a window opening June 25, 2003.

A split-crank bicycle ergometer uses servomotors to provide programmable pedal forces for studies in human biomechanics.

PubMed

Van der Loos, H F Machiel; Worthen-Chaudhari, Lise; Schwandt, Douglas; Bevly, David M; Kautz, Steven A

2010-08-01

This paper presents a novel computer-controlled bicycle ergometer, the TiltCycle, for use in human biomechanics studies of locomotion. The TiltCycle has a tilting (reclining) seat and backboard, a split pedal crankshaft to isolate the left and right loads to the feet of the pedaler, and two belt-driven, computer-controlled motors to provide assistance or resistance loads independently to each crank. Sensors measure the kinematics and force production of the legs to calculate work performed, and the system allows for goniometric and electromyography signals to be recorded. The technical description presented includes the mechanical design, low-level software and control algorithms, system identification and validation test results.

Imported pedal chancroid: case report.

PubMed Central

Marckmann, P; Højbjerg, T; von Eyben, F E; Christensen, I

1989-01-01

A man aged 22 who had returned from the Fiji Islands to Denmark had chancroid on the left foot, but no history or sign of primary genital infection. The pedal location only is an unusual presentation of the disease, which was diagnosed only microbiologically. Chronic tropical ulcers therefore demand special microbiological attention. Images PMID:2753511

49 CFR 570.55 - Hydraulic brake system.

Code of Federal Regulations, 2011 CFR

2011-10-01

... under a 125-pound force applied to the brake pedal and by no illumination of the brake system failure indicator lamp. The brake system shall withstand the application of force to the pedal without failure of... with power brake systems and the ignition turned to “on” in other vehicles, apply a force of 125 pounds...

49 CFR 570.55 - Hydraulic brake system.

Code of Federal Regulations, 2010 CFR

2010-10-01

... under a 125-pound force applied to the brake pedal and by no illumination of the brake system failure indicator lamp. The brake system shall withstand the application of force to the pedal without failure of... with power brake systems and the ignition turned to “on” in other vehicles, apply a force of 125 pounds...

49 CFR 570.55 - Hydraulic brake system.

Code of Federal Regulations, 2013 CFR

2013-10-01

... under a 125-pound force applied to the brake pedal and by no illumination of the brake system failure indicator lamp. The brake system shall withstand the application of force to the pedal without failure of... with power brake systems and the ignition turned to “on” in other vehicles, apply a force of 125 pounds...

49 CFR 570.55 - Hydraulic brake system.

Code of Federal Regulations, 2012 CFR

2012-10-01

... under a 125-pound force applied to the brake pedal and by no illumination of the brake system failure indicator lamp. The brake system shall withstand the application of force to the pedal without failure of... with power brake systems and the ignition turned to “on” in other vehicles, apply a force of 125 pounds...

49 CFR 570.55 - Hydraulic brake system.

Code of Federal Regulations, 2014 CFR

2014-10-01

... under a 125-pound force applied to the brake pedal and by no illumination of the brake system failure indicator lamp. The brake system shall withstand the application of force to the pedal without failure of... with power brake systems and the ignition turned to “on” in other vehicles, apply a force of 125 pounds...

The Relationship between Pedal Force and Crank Angular Velocity in Sprint Cycling.

PubMed

Bobbert, Maarten Frank; Casius, L J Richard; Van Soest, Arthur J

2016-05-01

Relationships between tangential pedal force and crank angular velocity in sprint cycling tend to be linear. We set out to understand why they are not hyperbolic, like the intrinsic force-velocity relationship of muscles. We simulated isokinetic sprint cycling at crank angular velocities ranging from 30 to 150 rpm with a forward dynamic model of the human musculoskeletal system actuated by eight lower extremity muscle groups. The input of the model was muscle stimulation over time, which we optimized to maximize average power output over a cycle. Peak tangential pedal force was found to drop more with crank angular velocity than expected based on intrinsic muscle properties. This linearizing effect was not due to segmental dynamics but rather due to active state dynamics. Maximizing average power in cycling requires muscles to bring their active state from as high as possible during shortening to as low as possible during lengthening. Reducing the active state is a relatively slow process, and hence must be initiated a certain amount of time before lengthening starts. As crank angular velocity goes up, this amount of time corresponds to a greater angular displacement, so the instant of switching off extensor muscle stimulation must occur earlier relative to the angle at which pedal force was extracted for the force-velocity relationship. Relationships between pedal force and crank angular velocity in sprint cycling do not reflect solely the intrinsic force-velocity relationship of muscles but also the consequences of activation dynamics.

Cars Gone Wild: The Major Contributor to Unintended Acceleration in Automobiles is Pedal Error.

PubMed

Schmidt, Richard A; Young, Douglas E

2010-01-01

"Unintended-acceleration" automobile accidents typically begin when the driver first enters the car, starts the engine, and intends to press his/her right foot on the brake while shifting from Park to a drive gear (Drive or Reverse). The driver reports an unintended (uncommanded) full-throttle acceleration, coupled with a loss of braking, until the episode ends in a crash. Pedal misapplications - where the right foot contacts the accelerator instead of the brake that was intended - have been linked to these accidents (Schmidt, 1989, 1993) which, in the 1980s, were thought to occur only at the start of a driving cycle (and/or with the car in Park). But, in 1997, we identified over 200 pedal errors as the cause of accidents reported in the North Carolina database; these crashes occurred during the driving cycle (Schmidt et al., 1997), and/or with the vehicle in a gear other than Park. Our present work provides a more thorough analysis of these North Carolina Police Accident Reports from 1979 to 1995. The vast majority of pedal misapplications (over 92%) (a) occurred during the driving cycle, (b) were generally in "unhurried" conditions, and (c) were categorically separate from those events referred to as unintended-acceleration episodes at start-up. These ideas are explanatory for the recent (2009-2010) surge of unintended-acceleration reports, perhaps even suggesting that all of these crashes are caused by pedal errors, and that none of them are based on some vehicle defect(s).

Relationship between oxygen uptake slow component and surface EMG during heavy exercise in humans: influence of pedal rate.

PubMed

Vercruyssen, Fabrice; Missenard, Olivier; Brisswalter, Jeanick

2009-08-01

The aim of this study was to test the hypothesis that extreme pedal rates contributed to the slow component of oxygen uptake (VO(2) SC) in association with changes in surface electromyographic (sEMG) during heavy-cycle exercise. Eight male trained cyclists performed two square-wave transitions at 50 and 110 rpm at a work rate that would elicit a VO(2) corresponding to 50% of the difference between peak VO(2) and the ventilatory threshold. Pulmonary gas exchange was measured breath-by-breath and sEMG was obtained from the vastus lateralis and medialis muscles. Integrated EMG flow (QiEMG) and mean power frequency (MPF) were computed. The relative amplitude of the VO(2) SC was significantly higher during the 110-rpm bout (556+/-186 ml min(-1), P<0.05) with compared to the 50-rpm bout (372+/-227 ml min(-1)). QiEMG values increased throughout exercise only during the 110-rpm bout and were associated with the greater amplitude of the VO(2) SC observed for this condition (P<0.05). MPF values remained relatively constant whatever the cycle bout. These findings indicated a VO(2) SC at the two pedal rates but the association with sEMG responses was observed only at high pedal rate. Possible changes in motor units recruitment pattern, muscle energy turnover and muscle temperature have been suggested to explain the different VO(2) SC to heavy pedal rate bouts.

Plantar and Pedal Puncture Wounds in Children: A Case Series Study From a Single Level I Trauma Center.

PubMed

Volk, Angela; Zebda, Mohamed; Abdelgawad, Amr A

2017-11-01

The purpose of this study was to describe our experience in treatment of pediatric patient presenting with pedal puncture wound to our level I trauma center and describe our results for the need for hospitalization and/or surgery for these patients. Children and adolescents 18 years and younger presenting with pedal puncture wounds from September 2009 to December of 2013 were retrospectively studied. Exclusion criteria included adult patients, wounds related to animal bites, lacerations associated with a motor vehicle collision or all-terrain vehicle accidents, gunshot wounds, degloving injuries, or injuries resulting in complex lacerations to the foot. A total of 147 children presented to emergency department (ED) with a pedal puncture wound. Average age was 9.8 years. Prophylactic antibiotic therapy was administered in 107 cases (72.8%). Fifteen patients (10%) were treated with intravenous or intramuscular antibiotics in the ED or after hospital admission, 81 patients (55%) were treated with oral medications (prescribed for them to be taken after discharge), and 35 patients (24%) received topical antibiotic treatment. Of the 147 patients included in the study, 9 patients (6%) required the need for hospitalization. Two patients were admitted for parenteral antibiotic treatment only, and 7 patients required formal surgical debridement in the operating room in addition to parenteral antibiotic therapy. The majority of pediatric patients with pedal puncture wounds were treated in the ED with only a small percentage of patients requiring admission for either parenteral antibiotic treatment or formal surgical debridement.

Modular mechatronic system for stationary bicycles interfaced with virtual environment for rehabilitation.

PubMed

Ranky, Richard G; Sivak, Mark L; Lewis, Jeffrey A; Gade, Venkata K; Deutsch, Judith E; Mavroidis, Constantinos

2014-06-05

Cycling has been used in the rehabilitation of individuals with both chronic and post-surgical conditions. Among the challenges with implementing bicycling for rehabilitation is the recruitment of both extremities, in particular when one is weaker or less coordinated. Feedback embedded in virtual reality (VR) augmented cycling may serve to address the requirement for efficacious cycling; specifically recruitment of both extremities and exercising at a high intensity. In this paper a mechatronic rehabilitation bicycling system with an interactive virtual environment, called Virtual Reality Augmented Cycling Kit (VRACK), is presented. Novel hardware components embedded with sensors were implemented on a stationary exercise bicycle to monitor physiological and biomechanical parameters of participants while immersing them in an augmented reality simulation providing the user with visual, auditory and haptic feedback. This modular and adaptable system attaches to commercially-available stationary bicycle systems and interfaces with a personal computer for simulation and data acquisition processes. The complete bicycle system includes: a) handle bars based on hydraulic pressure sensors; b) pedals that monitor pedal kinematics with an inertial measurement unit (IMU) and forces on the pedals while providing vibratory feedback; c) off the shelf electronics to monitor heart rate and d) customized software for rehabilitation. Bench testing for the handle and pedal systems is presented for calibration of the sensors detecting force and angle. The modular mechatronic kit for exercise bicycles was tested in bench testing and human tests. Bench tests performed on the sensorized handle bars and the instrumented pedals validated the measurement accuracy of these components. Rider tests with the VRACK system focused on the pedal system and successfully monitored kinetic and kinematic parameters of the rider's lower extremities. The VRACK system, a virtual reality mechatronic bicycle rehabilitation modular system was designed to convert most bicycles in virtual reality (VR) cycles. Preliminary testing of the augmented reality bicycle system was successful in demonstrating that a modular mechatronic kit can monitor and record kinetic and kinematic parameters of several riders.

Voluntary Movement Frequencies in Submaximal One- and Two-Legged Knee Extension Exercise and Pedaling

PubMed Central

Stang, Julie; Wiig, Håvard; Hermansen, Marte; Hansen, Ernst Albin

2016-01-01

Understanding of behavior and control of human voluntary rhythmic stereotyped leg movements is useful in work to improve performance, function, and rehabilitation of exercising, healthy, and injured humans. The present study aimed at adding to the existing understanding within this field. To pursue the aim, correlations between freely chosen movement frequencies in relatively simple, single-joint, one- and two-legged knee extension exercise were investigated. The same was done for more complex, multiple-joint, one- and two-legged pedaling. These particular activities were chosen because they could be considered related to some extent, as they shared a key aspect of knee extension, and because they at the same time were different. The activities were performed at submaximal intensities, by healthy individuals (n = 16, thereof eight women; 23.4 ± 2.7 years; 1.70 ± 0.11 m; 68.6 ± 11.2 kg). High and fair correlations (R-values of 0.99 and 0.75) occurred between frequencies generated with the dominant leg and the nondominant leg during knee extension exercise and pedaling, respectively. Fair to high correlations (R-values between 0.71 and 0.95) occurred between frequencies performed with each of the two legs in an activity, and the two-legged frequency performed in the same type of activity. In general, the correlations were higher for knee extension exercise than for pedaling. Correlations between knee extension and pedaling frequencies were of modest occurrence. The correlations between movement frequencies generated separately by each of the legs might be interpreted to support the following working hypothesis, which was based on existing literature. It is likely that involved central pattern generators (CPGs) of the two legs share a common frequency generator or that separate frequency generators of each leg are attuned via interneuronal connections. Further, activity type appeared to be relevant. Thus, the apparent common rhythmogenesis for the two legs appeared to be stronger for the relatively simple single-joint activity of knee extension exercise as compared to the more complex multi-joint activity of pedaling. Finally, it appeared that the shared aspect of knee extension in the related types of activities of knee extension exercise and pedaling was insufficient to cause obvious correlations between generated movement frequencies in the two types of activities. PMID:26973486

76 FR 8919 - Airworthiness Directives; DASSAULT AVIATION Model MYSTERE-FALCON 50 Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-16

... of the emergency brake system 2 located near the nose landing gear bearing were swapped. The swapping of these two pipes implies that when the Left Hand (LH) brake pedal is depressed, the Right Hand (RH) brake unit is activated, and conversely, when the RH brake pedal is depressed, the LH brake unit is...

76 FR 27880 - Airworthiness Directives; DASSAULT AVIATION Model MYSTERE-FALCON 50 Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-13

... pipes of the emergency brake system 2 located near the nose landing gear bearing were swapped. The swapping of these two pipes implies that when the Left Hand (LH) brake pedal is depressed, the Right Hand (RH) brake unit is activated, and conversely, when the RH brake pedal is depressed, the LH brake unit...

Assessing Constraints on Soldier Cognitive and Perceptual Motor Performance During Vehicle Motion

DTIC Science & Technology

2008-05-01

vehicle systems are biomechanical (Sirouspour & Salcudean, 2003; Sövényi & Gillespie, 2007), cognitive (Parasuraman & Riley, 1997), and psychomotor...vs. velocity), pedals for braking/acceleration Environmental constraints associated with the support surface (Seat): Damping, inclination...steering and secondarily, performance differences between a joystick and pedals for throttle and brake control. Eleven participants com- pleted three

Engineering Design Handbook: Analysis and Design of Automotive Brake Systems.

DTIC Science & Technology

1976-12-01

Highway Safety Research institute, Uni- versity of Michigan, September 15, 1972. IF’vn = (I - #)WT’,Kk I1, J. E. Bernard , et al,, A Computer Based...systems involve the reduction in brake line pres- 4. E. L. Cornwell , "Automatic Load-Sensitive Air sure for a given pedal force, the pedal force/de

Driving Skills of Young Adults with Developmental Coordination Disorder: Regulating Speed and Coping with Distraction

ERIC Educational Resources Information Center

de Oliveira, Rita F.; Wann, John P.

2011-01-01

In two experiments, we used an automatic car simulator to examine the steering control, speed regulation and response to hazards of young adults with developmental coordination disorder (DCD) and limited driving experience. In Experiment 1 participants either used the accelerator pedal to regulate their speed, or used the brake pedal when they…

Cars Gone Wild: The Major Contributor to Unintended Acceleration in Automobiles is Pedal Error

PubMed Central

Schmidt, Richard A.; Young, Douglas E.

2010-01-01

“Unintended-acceleration” automobile accidents typically begin when the driver first enters the car, starts the engine, and intends to press his/her right foot on the brake while shifting from Park to a drive gear (Drive or Reverse). The driver reports an unintended (uncommanded) full-throttle acceleration, coupled with a loss of braking, until the episode ends in a crash. Pedal misapplications – where the right foot contacts the accelerator instead of the brake that was intended – have been linked to these accidents (Schmidt, 1989, 1993) which, in the 1980s, were thought to occur only at the start of a driving cycle (and/or with the car in Park). But, in 1997, we identified over 200 pedal errors as the cause of accidents reported in the North Carolina database; these crashes occurred during the driving cycle (Schmidt et al., 1997), and/or with the vehicle in a gear other than Park. Our present work provides a more thorough analysis of these North Carolina Police Accident Reports from 1979 to 1995. The vast majority of pedal misapplications (over 92%) (a) occurred during the driving cycle, (b) were generally in “unhurried” conditions, and (c) were categorically separate from those events referred to as unintended-acceleration episodes at start-up. These ideas are explanatory for the recent (2009–2010) surge of unintended-acceleration reports, perhaps even suggesting that all of these crashes are caused by pedal errors, and that none of them are based on some vehicle defect(s). PMID:21833265

Changes of pedaling technique and muscle coordination during an exhaustive exercise.

PubMed

Dorel, Sylvain; Drouet, Jean-Marc; Couturier, Antoine; Champoux, Yvan; Hug, François

2009-06-01

Alterations of the mechanical patterns during an exhaustive pedaling exercise have been previously shown. We designed the present study to test the hypothesis that these alterations in the biomechanics of pedaling, which occur during exhaustive exercise, are linked to changes in the activity patterns of lower limb muscles. Ten well-trained cyclists were tested during a limited time to exhaustion, performing 80% of maximal power tolerated. Pedal force components were measured continuously using instrumented pedals and were synchronized with surface EMG signals measured in 10 lower limb muscles. The results confirmed most of the alterations of the mechanical patterns previously described in the literature. The magnitude of the root mean squared of the EMG during the complete cycle (RMScycle) for tibialis anterior and gastrocnemius medialis decreased significantly (P < 0.05) from 85% and 75% of Tlim, respectively. A higher RMScycle was obtained for gluteus maximus (P < 0.01) and biceps femoris (P < 0.05) from 75% of Tlim. The k values that resulted from the cross-correlation technique indicated that the activities of six muscles (gastrocnemius medialis, gastrocnemius lateralis, tibialis anterior, vastus lateralis, vastus medialis, and rectus femoris) were shifted forward in the cycle at the end of the exercise. The large increases in activity for gluteus maximus and biceps femoris, which are in accordance with the increase in force production during the propulsive phase, could be considered as instinctive coordination strategies that compensate for potential fatigue and loss of force of the knee extensors (i.e., vastus lateralis and vastus medialis) by a higher moment of the hip extensors.

Assessing the Flight Quality of a Large UAV for Sensors/Ground Robots Aerial Delivery

DTIC Science & Technology

2010-09-01

Lycoming 0320 - 0360 - Continental 0200 or any 100- 200hp 8. Wheels/ Brakes — Matco only 9. Wing skins — 2024-T3 alclad aircraft grade only (No...with full span trim 18. Rivets — Steel/steel and zinc plated pull type rivet 19. Rudder pedals — Dual rudder pedals toe brakes 20. Control systems

Guillain-Barré syndrome. Review and presentation of a case with pedal manifestations.

PubMed

Viegas, G V

1997-05-01

Guillan-Barré syndrome is an acute, symmetrical polyneuropathy with distinctive features. The early clinical course involves painful paresthesia that is usually followed by proximal motor weakness. Albuminocytologic dissociation in the cerebrospinal fluid is considered diagnostically important. Therapy ranges from supportive measures including physical therapy to surgical intervention for residual deformities. A case with pedal manifestations is presented.

Yo-Yo Pull Demonstration

ERIC Educational Resources Information Center

Layton, William

2013-01-01

A popular demonstration involves placing a yo-yo on a level table and gently pulling the string horizontally when it is wrapped to come out below the center of the yo-yo's axis. Students are then asked to predict which way the yo-yo will move. A similar demonstration is performed with a tricycle by pulling forward on a pedal with the pedal down in…

Time-to-collision analysis of pedestrian and pedal-cycle accidents for the development of autonomous emergency braking systems.

PubMed

Lenard, James; Welsh, Ruth; Danton, Russell

2018-06-01

The aim of this study was to describe the position of pedestrians and pedal cyclists relative to the striking vehicle in the 3 s before impact. This information is essential for the development of effective autonomous emergency braking systems and relevant test conditions for consumer ratings. The UK RAIDS-OTS study provided 175 pedestrian and 127 pedal-cycle cases based on in-depth, at-scene investigations of a representative sample of accidents in 2000-2010. Pedal cyclists were scattered laterally more widely than pedestrians (90% of cyclists within around ±80° compared to ±20° for pedestrians), however their distance from the striking vehicle in the seconds before impact was no greater (90% of cyclists within 42 m at 3 s compared to 50 m for pedestrians). This data is consistent with a greater involvement of slow moving vehicles in cycle accidents. The implication of the results is that AEB systems for cyclists require almost complete 180° side-to-side vision but do not need a longer distance range than for pedestrians. Copyright © 2018 Elsevier Ltd. All rights reserved.

A magnetorheological haptic cue accelerator for manual transmission vehicles

NASA Astrophysics Data System (ADS)

Han, Young-Min; Noh, Kyung-Wook; Lee, Yang-Sub; Choi, Seung-Bok

2010-07-01

This paper proposes a new haptic cue function for manual transmission vehicles to achieve optimal gear shifting. This function is implemented on the accelerator pedal by utilizing a magnetorheological (MR) brake mechanism. By combining the haptic cue function with the accelerator pedal, the proposed haptic cue device can transmit the optimal moment of gear shifting for manual transmission to a driver without requiring the driver's visual attention. As a first step to achieve this goal, a MR fluid-based haptic device is devised to enable rotary motion of the accelerator pedal. Taking into account spatial limitations, the design parameters are optimally determined using finite element analysis to maximize the relative control torque. The proposed haptic cue device is then manufactured and its field-dependent torque and time response are experimentally evaluated. Then the manufactured MR haptic cue device is integrated with the accelerator pedal. A simple virtual vehicle emulating the operation of the engine of a passenger vehicle is constructed and put into communication with the haptic cue device. A feed-forward torque control algorithm for the haptic cue is formulated and control performances are experimentally evaluated and presented in the time domain.

76 FR 13063 - Airworthiness Directives; EUROCOPTER FRANCE Model SA330F, SA330G, and SA330J Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-10

... beyond the end limit (``tall pilot'' position). This resulted in the separation of the pedal adjustment... the ``tall pilot'' stop nut was damaged, most likely due to aging of the adhesive. The nut came loose... the pedal unit on a SA 330 helicopter, the copilot set the position beyond the end limit (``tall pilot...

Bipedal vs. unipedal: a comparison between one-foot and two-foot driving in a driving simulator.

PubMed

Wang, Dong-Yuan Debbie; Richard, F Dan; Cino, Cullen R; Blount, Trevin; Schmuller, Joseph

2017-04-01

Is it better to drive with one foot or with two feet? Although two-foot driving has fostered interminable debate in the media, no scientific and systematic research has assessed this issue and federal and local state governments have provided no answers. The current study compared traditional unipedal (one-foot driving, using the right foot to control the accelerator and the brake pedal) with bipedal (two-foot driving, using the right foot to control the accelerator and the left foot to control the brake pedal) responses to a visual stimulus in a driving simulator study. Each of 30 undergraduate participants drove in a simulated driving scenario. They responded to a STOP sign displayed on the centre of the screen by bringing their vehicle to a complete stop. Brake RT was shorter under the bipedal condition, while throttle RT showed advantage under the unipedal condition. Stopping time and distance showed a bipedal advantage, however. We discuss further limitations of the current study and implications in a driving task. Before drawing any conclusions from the simulator study, further on-road driving tests are necessary to confirm these obtained bipedal advantages. Practitioner Summary: Traditional unipedal (using the right foot to control the accelerator and the brake pedal) with bipedal (using the right foot to control the accelerator and the left foot to control the brake pedal) responses to a visual stimulus in a driving simulator were compared. Our results showed a bipedal advantage. Promotion: Although two-foot driving has fostered interminable debate in the media, no scientific and systematic research has assessed this issue and federal and local state governments have provided no answers. Traditional (one-foot driving, using the right foot to control the accelerator and the brake pedal) with bipedal (using the right foot to control the accelerator and the left foot to control the brake pedal) responses to a visual stimulus in a simulated driving study were compared. Throttle reaction time was faster in the unipedal condition whereas brake reaction time, stopping time and stopping distance showed a bipedal advantage. We discuss further theoretical issues and implications in a driving task.

A biofeedback cycling training to improve locomotion: a case series study based on gait pattern classification of 153 chronic stroke patients.

PubMed

Ferrante, Simona; Ambrosini, Emilia; Ravelli, Paola; Guanziroli, Eleonora; Molteni, Franco; Ferrigno, Giancarlo; Pedrocchi, Alessandra

2011-08-24

The restoration of walking ability is the main goal of post-stroke lower limb rehabilitation and different studies suggest that pedaling may have a positive effect on locomotion. The aim of this study was to explore the feasibility of a biofeedback pedaling treatment and its effects on cycling and walking ability in chronic stroke patients. A case series study was designed and participants were recruited based on a gait pattern classification of a population of 153 chronic stroke patients. In order to optimize participants selection, a k-means cluster analysis was performed to subgroup homogenous gait patterns in terms of gait speed and symmetry.The training consisted of a 2-week treatment of 6 sessions. A visual biofeedback helped the subjects in maintaining a symmetrical contribution of the two legs during pedaling. Participants were assessed before, after training and at follow-up visits (one week after treatment). Outcome measures were the unbalance during a pedaling test, and the temporal, spatial, and symmetry parameters during gait analysis. Three clusters, mainly differing in terms of gait speed, were identified and participants, representative of each cluster, were selected.An intra-subject statistical analysis (ANOVA) showed that all patients significantly decreased the pedaling unbalance after treatment and maintained significant improvements with respect to baseline at follow-up. The 2-week treatment induced some modifications in the gait pattern of two patients: one, the most impaired, significantly improved mean velocity and increased gait symmetry; the other one reduced significantly the over-compensation of the healthy limb. No benefits were produced in the gait of the last subject who maintained her slow but almost symmetrical pattern. Thus, this study might suggest that the treatment can be beneficial for patients having a very asymmetrical and inefficient gait and for those that overuse the healthy leg. The results demonstrated that the treatment is feasible and it might be effective in translating progresses from pedaling to locomotion. If these results are confirmed on a larger and controlled scale, the intervention, thanks to its safety and low price, could have a significant impact as a home- rehabilitation treatment for chronic stroke patients.

Modular mechatronic system for stationary bicycles interfaced with virtual environment for rehabilitation

PubMed Central

2014-01-01

Background Cycling has been used in the rehabilitation of individuals with both chronic and post-surgical conditions. Among the challenges with implementing bicycling for rehabilitation is the recruitment of both extremities, in particular when one is weaker or less coordinated. Feedback embedded in virtual reality (VR) augmented cycling may serve to address the requirement for efficacious cycling; specifically recruitment of both extremities and exercising at a high intensity. Methods In this paper a mechatronic rehabilitation bicycling system with an interactive virtual environment, called Virtual Reality Augmented Cycling Kit (VRACK), is presented. Novel hardware components embedded with sensors were implemented on a stationary exercise bicycle to monitor physiological and biomechanical parameters of participants while immersing them in an augmented reality simulation providing the user with visual, auditory and haptic feedback. This modular and adaptable system attaches to commercially-available stationary bicycle systems and interfaces with a personal computer for simulation and data acquisition processes. The complete bicycle system includes: a) handle bars based on hydraulic pressure sensors; b) pedals that monitor pedal kinematics with an inertial measurement unit (IMU) and forces on the pedals while providing vibratory feedback; c) off the shelf electronics to monitor heart rate and d) customized software for rehabilitation. Bench testing for the handle and pedal systems is presented for calibration of the sensors detecting force and angle. Results The modular mechatronic kit for exercise bicycles was tested in bench testing and human tests. Bench tests performed on the sensorized handle bars and the instrumented pedals validated the measurement accuracy of these components. Rider tests with the VRACK system focused on the pedal system and successfully monitored kinetic and kinematic parameters of the rider’s lower extremities. Conclusions The VRACK system, a virtual reality mechatronic bicycle rehabilitation modular system was designed to convert most bicycles in virtual reality (VR) cycles. Preliminary testing of the augmented reality bicycle system was successful in demonstrating that a modular mechatronic kit can monitor and record kinetic and kinematic parameters of several riders. PMID:24902780

The influence of cadence and power output on force application and in-shoe pressure distribution during cycling by competitive and recreational cyclists.

PubMed

Sanderson, D J; Hennig, E M; Black, A H

2000-03-01

The aim of this study was to determine the response of cyclists to manipulations of cadence and power output in terms of force application and plantar pressure distribution. Two groups of cyclists, 17 recreational and 12 competitive, rode at three nominal cadences (60, 80, 100 rev x min(-1)) and four power outputs (100, 200, 300, 400 W) while simultaneous force and in-shoe pressure data were collected. Two piezoelectric triaxial force transducers mounted in the right pedal measured components of the pedal force and orientation, and a discrete transducer system with 12 transducers recorded the in-shoe pressures. Force application was characterized by calculating peak resultant and peak effective pedal forces and positive and negative impulses. In-shoe pressures were analysed as peak pressures and as the percent relative load. The force data showed no significant group effect but there was a cadence and power main effect. The impulse data showed a significant three-way interaction. Increased cadence resulted in a decreased positive impulse, while increased power output resulted in an increased impulse. The competitive group produced less positive impulse but the difference became less at higher cadences. Few between-group differences were found in pressure, notable only in the pressure under the first metatarsal region. This showed a consistent pattern of in-shoe pressure distribution, where the primary loading structures were the first metatarsal and hallux. There was no indication that pressure at specific sites influenced the pedal force application. The absence of group differences indicated that pressure distribution was not the result of training, but reflected the intrinsic relationship between the foot, the shoe and the pedal.

Muscle activity adapts to anti-gravity posture during pedalling in persons with post-stroke hemiplegia.

PubMed

Brown, D A; Kautz, S A; Dairaghi, C A

1997-05-01

With hemiplegia following stroke, a person's movement response to anti-gravity posture often appears rigid and inflexible, exacerbating the motor dysfunction. A major determinant of pathological movement in anti-gravity postures is the failure to adapt muscle-activity patterns automatically to changes in posture. The aim of the present study was to determine whether the impaired motor performance observed when persons with hemiplegia pedal in a horizontal position is exacerbated at more vertical anti-gravity body orientations. Twelve healthy elderly subjects and 17 subjects with chronic (> 6 months) post-stroke hemiplegia participated in the study. Subjects pedalled a modified ergometer at different body orientations (from horizontal to vertical), maintaining the same workload, cadence, and hip and knee kinematics. Pedal reaction forces, and crank and pedal kinematics, were measured and then used to calculate the work done by each leg and their net positive and negative components. The EMG was recorded from four leg muscles (tibialis anterior, medial gastrocnemius, rectus femoris and biceps femoris). The main result from this study was that impaired plegic leg performance, as measured by net negative work done by the plegic leg and abnormal early rectus femoris activity, was exacerbated at the most vertical body orientations. However, contrary to the belief that muscle activity cannot adapt to anti-gravity postures, net positive work increased appropriately and EMG activity in all muscles showed modulated levels of activity similar to those in elderly control subjects. These results support the hypothesis that increased verticality exacerbates the already impaired movement performance. Yet, much of the motor response to verticality was flexible and appropriate, given the mechanics of the task.

Mechanical design and driving mechanism of an isokinetic functional electrical stimulation-based leg stepping trainer.

PubMed

Hamzaid, N A; Fornusek, C; Ruys, A; Davis, G M

2007-12-01

The mechanical design of a constant velocity (isokinetic) leg stepping trainer driven by functional electrical stimulation-evoked muscle contractions was the focus of this paper. The system was conceived for training the leg muscles of neurologically-impaired patients. A commercially available slider crank mechanism for elliptical stepping exercise was adapted to a motorized isokinetic driving mechanism. The exercise system permits constant-velocity pedalling at cadences of 1-60 rev x min(-1). The variable-velocity feature allows low pedalling forces for individuals with very weak leg muscles, yet provides resistance to higher pedalling effort in stronger patients. In the future, the system will be integrated with a computer-controlled neuromuscular stimulator and a feedback control unit to monitor training responses of spinal cord-injured, stroke and head injury patients.

Measurement of forces applied to handgrips and pedals for a sample population of Mexican males.

PubMed

Lara-Lopez, A; Aguilera-Cortes, L A; Barbosa-Castillo, F

1999-04-01

Equipment design requirements for newly industrializing nations often differ from those of highly industrialized nations. In order to develop a 'culturally relevant' technology in Mexico, this paper reports the results of a study, conducted in Guanajuato state, designed to measure the maximum static forces exerted on pulling handgrips and pedals by seated male subjects. The project included the design and construction of an adjustable measuring apparatus. Handgrip measurements were taken with left and right arms at five different elbow angles; pedal measurements with left and right legs at three different knee angles. The arm data indicate that the relationship between appendage angle and force is similar for these data and those previously reported for a US sample, although there are some significant differences in magnitude. Implications of these results for machinery design are discussed.

Dismounted Warrior Network Experiments

DTIC Science & Technology

2000-11-01

Foxtrot Locomotion Human Joystick ODT Joystick Foot Pedal + Head Orientation Visual Display Wireless HMD 4 Projection Desktop Single Screens (WISE... Biomechanics DI-Guy JackML DI-Guy Table 1. VICs Comparison Matrix VIC Alpha is the Dismounted Soldier Simulation (DSS) system developed by Veda, Inc. under a...using a pressure sensitive foot pedal . The user’s head is tracked with a magnetic sensor and is used to control steering through the environment. A

AD Hoc Study on Human Robot Interface Issues

DTIC Science & Technology

2002-09-01

of joint range of motion limits on strength. When the angle of a fully deflected aircraft rudder/ brake pedal is beyond the limit of ankle...mobility, the pedal will seem to have excessive resistance. In addition, this will prevent the pilot from fully utilizing the brakes of the aircraft...importance and value added of HE efforts. 34 Center High-Mounted Brake Lights. In 1985, after extensive HE studies showing positive

A new crank arm based load cell, with built-in conditioning circuit and strain gages, to measure the components of the force applied by a cyclist.

PubMed

Pigatto, Andre V; Moura, Karina O A; Favieiro, Gabriela W; Balbinot, Alexandre

2016-08-01

This report describes the development of a force platform based on instrumented load cells with built-in conditioning circuit and strain gages to measure and acquire the components of the force that is applied to the bike crank arm during pedaling in real conditions, and save them on a SD Card. To accomplish that, a complete new crank arm 3D solid model was developed in the SolidWorks, with dimensions equivalent to a commercial crank set and compatible with a conventional road bike, but with a compartment to support all the electronics necessary to measure 3 components of the force applied to the pedal during pedaling. After that, a 6082 T6 Aluminum Crankset based on the solid model was made and instrumented with three Wheatstone bridges each. The signals were conditioned on a printed circuit board, made on SMD technology, and acquired using a microcontroller with a DAC. Static deformation analysis showed a linearity error below 0.6% for all six channels. Dynamic analysis showed a natural frequency above 136Hz. A one-factor experiment design was performed with 5 amateur cyclists. ANOVA showed that the cyclist weight causes significant variation on the force applied to the bicycle pedal and its bilateral symmetry.

Neuro-Mechanics of Recumbent Leg Cycling in Post-Acute Stroke Patients.

PubMed

Ambrosini, Emilia; De Marchis, Cristiano; Pedrocchi, Alessandra; Ferrigno, Giancarlo; Monticone, Marco; Schmid, Maurizio; D'Alessio, Tommaso; Conforto, Silvia; Ferrante, Simona

2016-11-01

Cycling training is strongly applied in post-stroke rehabilitation, but how its modular control is altered soon after stroke has been not analyzed yet. EMG signals from 9 leg muscles and pedal forces were measured bilaterally during recumbent pedaling in 16 post-acute stroke patients and 12 age-matched healthy controls. Patients were asked to walk over a GaitRite mat and standard gait parameters were computed. Four muscle synergies were extracted through nonnegative matrix factorization in healthy subjects and patients unaffected legs. Two to four synergies were identified in the affected sides and the number of synergies significantly correlated with the Motricity Index (Spearman's coefficient = 0.521). The reduced coordination complexity resulted in a reduced biomechanical performance, with the two-module sub-group showing the lowest work production and mechanical effectiveness in the affected side. These patients also exhibited locomotor impairments (reduced gait speed, asymmetrical stance time, prolonged double support time). Significant correlations were found between cycling-based metrics and gait parameters, suggesting that neuro-mechanical quantities of pedaling can inform on walking dysfunctions. Our findings support the use of pedaling as a rehabilitation method and an assessment tool after stroke, mainly in the early phase, when patients can be unable to perform a safe and active gait training.

Performance and physiological effects of different descending strategies for cross-country mountain biking.

PubMed

Miller, Matthew C; Macdermid, Paul W; Fink, Phil W; Stannard, Stephen R

2017-04-01

This study investigated the performance-related feasibility and physiological benefits of purposefully eliminating propulsive work while descending in mountain biking and compared values to those measured during road descending. Participants cycled uphill on a road at race pace before descending over three conditions (off-road pedalling; off-road coasting; road coasting). Relatively low power output during off-road pedalling was associated with a greater oxygen uptake (p < .01) when compared with off-road coasting despite no difference in vibration exposure (p > .05). Importantly, pedalling did not invoke a performance benefit (p > .05) on the descent used in this study. Significantly greater heart rate and oxygen uptake (both p < .01) were observed between road and off-road descending, likely caused by the increase in terrain-induced vibrations (p < .01) experienced between the bicycle and rider. Results indicate that reducing propulsive work during descending can improve recovery without being disadvantageous to performance. Similarly, the vibrations experienced during road descending are relatively low, and further reduce oxygen cost. In an effort to increase efficiency, it is recommended that mountain bike athletes focus on skills to increase descending speed without the addition of pedalling, and that equipment be used to decrease vibrations nearer to those seen on the road.

Study to Determine the Impact of Aircrew Anthropometry on Airframe Configuration.

DTIC Science & Technology

1976-10-31

Fie t0) PILO PEDAL 1F.A STR ~fAW1 I Il. VD 2. LEAAN II)W HANYJ(ON MAX 817E FOOTWFAII. TOIIIOMKM Sitfi4I FORWARDN) Nou v ims-ritAIT% InhITKIN WiT11 lILL...designed as specified in Figure 18. 7.4.3 Xaw Control. Pedal munge - Forward and aft limits of yaw controls shall be as defined in Figures 16 and 17. 8

Fecal Impaction Causing Pelvic Venous Compression and Edema.

PubMed

Naramore, Sara; Aziz, Faisal; Alexander, Chandran Paul; Methratta, Sosamma; Cilley, Robert; Rocourt, Dorothy

2015-09-28

Chronic constipation is a common condition which may result in fecal impaction. A 13-year-old male with chronic constipation and encopresis presented with fecal impaction for three weeks. The impaction caused abdominal pain, distension, encopresis, and decreased oral intake. He was found in severe distress with non-pitting edema of his feet and ankles along with perineal edema. The pedal edema worsened after receiving a fluid bolus, so concern arose for venous compression or a thrombus. A Duplex Ultrasound demonstrated changes in the venous waveforms of the bilateral external iliac and common femoral veins without thrombosis. Manual disimpaction and polyethylene glycol 3350 with electrolytes resolved the pedal and perineal edema. Four months later, he had soft bowel movements without recurrence of the edema. A repeat Duplex Ultrasound was normal. We present a child in whom severe fecal impaction caused pelvic venous compression resulting in bilateral pedal and perineal edema.

Fecal Impaction Causing Pelvic Venous Compression and Edema

PubMed Central

Naramore, Sara; Aziz, Faisal; Alexander, Chandran Paul; Methratta, Sosamma; Cilley, Robert; Rocourt, Dorothy

2015-01-01

Chronic constipation is a common condition which may result in fecal impaction. A 13-year-old male with chronic constipation and encopresis presented with fecal impaction for three weeks. The impaction caused abdominal pain, distension, encopresis, and decreased oral intake. He was found in severe distress with non-pitting edema of his feet and ankles along with perineal edema. The pedal edema worsened after receiving a fluid bolus, so concern arose for venous compression or a thrombus. A Duplex Ultrasound demonstrated changes in the venous waveforms of the bilateral external iliac and common femoral veins without thrombosis. Manual disimpaction and polyethylene glycol 3350 with electrolytes resolved the pedal and perineal edema. Four months later, he had soft bowel movements without recurrence of the edema. A repeat Duplex Ultrasound was normal. We present a child in whom severe fecal impaction caused pelvic venous compression resulting in bilateral pedal and perineal edema. PMID:26500749

Auditory and visual cueing modulate cycling speed of older adults and persons with Parkinson's disease in a Virtual Cycling (V-Cycle) system.

PubMed

Gallagher, Rosemary; Damodaran, Harish; Werner, William G; Powell, Wendy; Deutsch, Judith E

2016-08-19

Evidence based virtual environments (VEs) that incorporate compensatory strategies such as cueing may change motor behavior and increase exercise intensity while also being engaging and motivating. The purpose of this study was to determine if persons with Parkinson's disease and aged matched healthy adults responded to auditory and visual cueing embedded in a bicycling VE as a method to increase exercise intensity. We tested two groups of participants, persons with Parkinson's disease (PD) (n = 15) and age-matched healthy adults (n = 13) as they cycled on a stationary bicycle while interacting with a VE. Participants cycled under two conditions: auditory cueing (provided by a metronome) and visual cueing (represented as central road markers in the VE). The auditory condition had four trials in which auditory cues or the VE were presented alone or in combination. The visual condition had five trials in which the VE and visual cue rate presentation was manipulated. Data were analyzed by condition using factorial RMANOVAs with planned t-tests corrected for multiple comparisons. There were no differences in pedaling rates between groups for both the auditory and visual cueing conditions. Persons with PD increased their pedaling rate in the auditory (F 4.78, p = 0.029) and visual cueing (F 26.48, p < 0.000) conditions. Age-matched healthy adults also increased their pedaling rate in the auditory (F = 24.72, p < 0.000) and visual cueing (F = 40.69, p < 0.000) conditions. Trial-to-trial comparisons in the visual condition in age-matched healthy adults showed a step-wise increase in pedaling rate (p = 0.003 to p < 0.000). In contrast, persons with PD increased their pedaling rate only when explicitly instructed to attend to the visual cues (p < 0.000). An evidenced based cycling VE can modify pedaling rate in persons with PD and age-matched healthy adults. Persons with PD required attention directed to the visual cues in order to obtain an increase in cycling intensity. The combination of the VE and auditory cues was neither additive nor interfering. These data serve as preliminary evidence that embedding auditory and visual cues to alter cycling speed in a VE as method to increase exercise intensity that may promote fitness.

A biofeedback cycling training to improve locomotion: a case series study based on gait pattern classification of 153 chronic stroke patients

PubMed Central

2011-01-01

Background The restoration of walking ability is the main goal of post-stroke lower limb rehabilitation and different studies suggest that pedaling may have a positive effect on locomotion. The aim of this study was to explore the feasibility of a biofeedback pedaling treatment and its effects on cycling and walking ability in chronic stroke patients. A case series study was designed and participants were recruited based on a gait pattern classification of a population of 153 chronic stroke patients. Methods In order to optimize participants selection, a k-means cluster analysis was performed to subgroup homogenous gait patterns in terms of gait speed and symmetry. The training consisted of a 2-week treatment of 6 sessions. A visual biofeedback helped the subjects in maintaining a symmetrical contribution of the two legs during pedaling. Participants were assessed before, after training and at follow-up visits (one week after treatment). Outcome measures were the unbalance during a pedaling test, and the temporal, spatial, and symmetry parameters during gait analysis. Results and discussion Three clusters, mainly differing in terms of gait speed, were identified and participants, representative of each cluster, were selected. An intra-subject statistical analysis (ANOVA) showed that all patients significantly decreased the pedaling unbalance after treatment and maintained significant improvements with respect to baseline at follow-up. The 2-week treatment induced some modifications in the gait pattern of two patients: one, the most impaired, significantly improved mean velocity and increased gait symmetry; the other one reduced significantly the over-compensation of the healthy limb. No benefits were produced in the gait of the last subject who maintained her slow but almost symmetrical pattern. Thus, this study might suggest that the treatment can be beneficial for patients having a very asymmetrical and inefficient gait and for those that overuse the healthy leg. Conclusion The results demonstrated that the treatment is feasible and it might be effective in translating progresses from pedaling to locomotion. If these results are confirmed on a larger and controlled scale, the intervention, thanks to its safety and low price, could have a significant impact as a home- rehabilitation treatment for chronic stroke patients. PMID:21861930

Effects of two hospital bed design features on physical demands and usability during brake engagement and patient transportation: a repeated measures experimental study.

PubMed

Kim, Sunwook; Barker, Linsey M; Jia, Bochen; Agnew, Michael J; Nussbaum, Maury A

2009-03-01

Work-related musculoskeletal disorders (WMSDs) are prevalent among healthcare workers worldwide. While existing research has focused on patient-handling techniques during activities which require direct patient contact (e.g., patient transfer), nursing tasks also involve other patient-handling activities, such as engaging bed brakes and transporting patients in beds, which could render healthcare workers at risk of developing WMSDs. Effectiveness of hospital bed design features (brake pedal location and steering-assistance) was evaluated in terms of physical demands and usability during brake engagement and patient transportation tasks. Two laboratory-based studies were conducted. In simulated brake engagement tasks, three brake pedal locations (head-end vs. foot-end vs. side of a bed) and two hands conditions (hands-free vs. hands-occupied) were manipulated. Additionally, both in-room and corridor patient transportation tasks were simulated, in which activation of steering-assistance features (5th wheel and/or front wheel caster lock) and two patient masses were manipulated. Nine novice participants were recruited from the local student population and community for each study. During brake engagement, trunk flexion angle, task completion time, and questionnaires were used to quantify postural comfort and usability. For patient transportation, dependent measures were hand forces and questionnaire responses. Brake pedal locations and steering-assistance features in hospital beds had significant effects on physical demands and usability during brake engagement and patient transportation tasks. Specifically, a brake pedal at the head-end of a bed increased trunk flexion by 74-224% and completion time by 53-74%, compared to other pedal locations. Participants reported greater overall perceived difficulty and less postural comfort with the brake pedal at the head-end. During in-room transportation, participants generally reported "Neither Low nor High" physical demands with the 5th wheel activated, compared to "Moderately High" physical demands when the 5th wheel was deactivated. Corridor transportation was similarly reported to be easier when a steering-assistance feature (the 5th wheel or front caster lock) was activated. Braking and steering-assistance features of hospital beds can have important effects on task efficiency and physical demands placed on healthcare workers. Selection of specific designs may thus be able to improve productivity and contribute to a reduction in WMSDs risk among healthcare workers.

Selected Design Parameters for Reclining Seats Based on Engineering Anthropometry

DTIC Science & Technology

1977-09-01

mounted on these arm rests and immediately adjacent surfaces -provide upper extremity configuratinns conducive to maximum biomechanical advantage -meet...operation at the rudder pedals under normal or under high G environments. (2) Size: The foot rest must be large enough to cover the range of heel positions...See Figure 9.) Foot Control Adjustment Two horizontal cylinders 2" in diameter x 6" long represented rudder pedals to be operated by feet. They were

Accuracy of intensity and inclinometer output of three activity monitors for identification of sedentary behavior and light-intensity activity.

PubMed

Carr, Lucas J; Mahar, Matthew T

2012-01-01

Purpose. To examine the accuracy of intensity and inclinometer output of three physical activity monitors during various sedentary and light-intensity activities. Methods. Thirty-six participants wore three physical activity monitors (ActiGraph GT1M, ActiGraph GT3X+, and StepWatch) while completing sedentary (lying, sitting watching television, sitting using computer, and standing still) light (walking 1.0 mph, pedaling 7.0 mph, pedaling 15.0 mph) intensity activities under controlled settings. Accuracy for correctly categorizing intensity was assessed for each monitor and threshold. Accuracy of the GT3X+ inclinometer function (GT3X+Incl) for correctly identifying anatomical position was also assessed. Percentage agreement between direct observation and the monitor recorded time spent in sedentary behavior and light intensity was examined. Results. All monitors using all thresholds accurately identified over 80% of sedentary behaviors and 60% of light-intensity walking time based on intensity output. The StepWatch was the most accurate in detecting pedaling time but unable to detect pedal workload. The GT3X+Incl accurately identified anatomical position during 70% of all activities but demonstrated limitations in discriminating between activities of differing intensity. Conclusions. Our findings suggest that all three monitors accurately measure most sedentary and light-intensity activities although choice of monitors should be based on study-specific needs.

Lower Wingate Test Power Outcomes From "All-Out" Pretest Pedaling Cadence Compared With Moderate Cadence.

PubMed

Lunn, William R; Zenoni, Maria A; Crandall, Ian H; Dress, Ashley E; Berglund, Michelle L

2015-08-01

The aim of the present study was to determine the effect of different pretest pedaling cadences on power outcomes obtained during the Wingate Anaerobic Test (WAnT). Vigorously exercising adult men (n = 14, 24.9 ± 1.2 years) and women (n = 14, 20.4 ± 0.6 years) participated in a randomized crossover study during which they performed the 30-second WAnT on a mechanically braked cycle ergometer (0.075 kg·kg(-1) body weight) under 2 conditions. Participants pedaled maximally with an unloaded flywheel during 5 seconds before resistance was applied and the test began (FAST). In another trial, participants maintained a moderate cadence (80 revolutions per minute [rpm]) during 5 seconds before the test began (MOD). All other components of the WAnT were identical. Peak power (PP), mean power (MP), minimum power (MinP), fatigue index (%FAT), and maximum cadence during test were recorded. Comparisons were made using a 2 × 2 factorial repeated-measures analysis of variance. Regardless of gender, the FAST condition resulted in 22.2% lower PP (612.6 ± 33.0 W vs. 788.3 ± 43.5 W), 13.3% lower MP (448.4 ± 22.2 W vs. 517.2 ± 26.4 W), 11.7% lower MinP (280.9 ± 14.8 W vs. 318.3 ± 17.2 W), and 9.0% lower %FAT (53.5 ± 1.3% vs. 58.8 ± 1.5%) than MOD condition (p < 0.01; mean ± SD). Similar outcomes were observed within gender. The authors conclude that practitioners of the WAnT should instruct participants to maintain a moderate pedal cadence (∼80 rpm) during 5 seconds before the test commences to avoid bias from software sampling and peripheral fatigue. Standardizing the pretest pedal cadence will be important to exercise testing professionals who compare data with norms or generate norms for specific populations.

Goniometric measurement of hip motion in cycling while standing.

PubMed

Hull, M L; Beard, A; Varma, H

1990-01-01

The purpose of this study was to develop an instrument for quantifying the motion of the hip relative to the bicycle while cycling in the standing position. Because of the need to measure hip motion on the road as well as in the laboratory, a goniometer which locates the hip using spherical coordinates was designed. The goniometer is presented first, followed by the development of the equations that enable the distance from the joint center to the pedal spindle to be determined. The orientation of this line segment is specified by calculating two angles referenced to the frame. Also outlined are the procedures used to both calibrate the goniometer and perform an accuracy check. The results of this check indicate that the attachment point of the goniometer to the rider can be located to within 2.5 mm of the true position. The goniometer was used to record the hip movement patterns of six subjects who cycled in the standing position on a treadmill. Representative results from one test subject who cycled at 6% grade and 25 km h-1 are presented. Results indicate that the bicycle is leaned from side to side with the frequency of leaning equal to the frequency of pedalling. Extreme lean angles are +/- 6 degrees. The distance from the hip to the pedal varies approximately sinusoidally with frequency equal to pedalling rate and amplitude somewhat less than crank arm length. The absolute elevation of the hip, however, exhibits two cycles for each crank cycle. Asymmetry in the plot of elevation over a single crank cycle indicates that the pelvis rocks from side to side and that the elevation of the pelvis midpoint changes. Extreme values of the pelvis rocking angle are +/- 12 degrees. Highest pelvis midpoint elevations, however, do not occur at the same crank angles as those angles at which the pelvis rocking is extreme. It appears that the vertical motion of the hips affects pedalling mechanics when cycling in the standing position.

A reduction of the saddle vertical force triggers the sit-stand transition in cycling.

PubMed

Costes, Antony; Turpin, Nicolas A; Villeger, David; Moretto, Pierre; Watier, Bruno

2015-09-18

The purpose of the study was to establish the link between the saddle vertical force and its determinants in order to establish the strategies that could trigger the sit-stand transition. We hypothesized that the minimum saddle vertical force would be a critical parameter influencing the sit-stand transition during cycling. Twenty-five non-cyclists were asked to pedal at six different power outputs from 20% (1.6 ± 0.3 W kg(-1)) to 120% (9.6 ± 1.6 W kg(-1)) of their spontaneous sit-stand transition power obtained at 90 rpm. Five 6-component sensors (saddle tube, pedals and handlebars) and a full-body kinematic reconstruction were used to provide the saddle vertical force and other force components (trunk inertial force, hips and shoulders reaction forces, and trunk weight) linked to the saddle vertical force. Minimum saddle vertical force linearly decreased with power output by 87% from a static position on the bicycle (5.30 ± 0.50 N kg(-1)) to power output=120% of the sit-stand transition power (0.68 ± 0.49 N kg(-1)). This decrease was mainly explained by the increase in instantaneous pedal forces from 2.84 ± 0.58 N kg(-1) to 6.57 ± 1.02 N kg(-1) from 20% to 120% of the power output corresponding to the sit-stand transition, causing an increase in hip vertical forces from -0.17 N kg(-1) to 3.29 N kg(-1). The emergence of strategies aiming at counteracting the elevation of the trunk (handlebars and pedals pulling) coincided with the spontaneous sit-stand transition power. The present data suggest that the large decrease in minimum saddle vertical force observed at high pedal reaction forces might trigger the sit-stand transition in cycling. Copyright © 2015 Elsevier Ltd. All rights reserved.

Maintenance of safety behaviors via response-produced stimuli.

PubMed

Angelakis, Ioannis; Austin, Jennifer L

2015-11-01

Animal studies suggest that safety behaviors may be maintained by internally or externally produced safety signals, which function as positive reinforcers. We designed two experiments to test this phenomenon with humans. Participants played a computerized game in which they could earn or lose treasures by clicking on a map. In baseline, losses could be postponed by pressing a pedal that also produced a blue bar at the bottom of the screen. During test conditions, no losses were programmed, and pedal presses turned the bar from yellow to blue (Test 1) or blue to yellow (Test 2). In Experiment 2, new participants were exposed to the same conditions but were given information about the safety of the test environment. In both experiments, participants engaged in high rates of pedal pressing when presses were followed by blue bars, suggesting the bar functioned as a safety signal. We discuss how these findings may relate to safety behaviors commonly observed in certain mental health disorders. © The Author(s) 2015.

Laboratory versus outdoor cycling conditions: differences in pedaling biomechanics.

PubMed

Bertucci, William; Grappe, Frederic; Groslambert, Alain

2007-05-01

The aim of our study was to compare crank torque profile and perceived exertion between the Monark ergometer (818 E) and two outdoor cycling conditions: level ground and uphill road cycling. Seven male cyclists performed seven tests in seated position at different pedaling cadences: (a) in the laboratory at 60, 80, and 100 rpm; (b) on level terrain at 80 and 100 rpm; and (c) on uphill terrain (9.25% grade) at 60 and 80 rpm. The cyclists exercised for 1 min at their maximal aerobic power. The Monark ergometer and the bicycle were equipped with the SRM Training System (Schoberer, Germany) for the measurement of power output (W), torque (Nxm), pedaling cadence (rpm), and cycling velocity (kmxh-1). The most important findings of this study indicate that at maximal aerobic power the crank torque profiles in the Monark ergometer (818 E) were significantly different (especially on dead points of the crank cycle) and generate a higher perceived exertion compared with road cycling conditions.

A haptic pedal for surgery assistance.

PubMed

Díaz, Iñaki; Gil, Jorge Juan; Louredo, Marcos

2014-09-01

The research and development of mechatronic aids for surgery is a persistent challenge in the field of robotic surgery. This paper presents a new haptic pedal conceived to assist surgeons in the operating room by transmitting real-time surgical information through the foot. An effective human-robot interaction system for medical practice must exchange appropriate information with the operator as quickly and accurately as possible. Moreover, information must flow through the appropriate sensory modalities for a natural and simple interaction. However, users of current robotic systems might experience cognitive overload and be increasingly overwhelmed by data streams from multiple modalities. A new haptic channel is thus explored to complement and improve existing systems. A preliminary set of experiments has been carried out to evaluate the performance of the proposed system in a virtual surgical drilling task. The results of the experiments show the effectiveness of the haptic pedal in providing surgical information through the foot. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

GT3X+ accelerometer placement affects the reliability of step-counts measured during running and pedal-revolution counts measured during bicycling.

PubMed

Gatti, Anthony A; Stratford, Paul W; Brenneman, Elora C; Maly, Monica R

2016-01-01

Accelerometers provide a measure of step-count. Reliability and validity of step-count and pedal-revolution count measurements by the GT3X+ accelerometer, placed at different anatomical locations, is absent in the literature. The purpose of this study was to investigate the reliability and validity of step and pedal-revolution counts produced by the GT3X+ placed at different anatomical locations during running and bicycling. Twenty-two healthy adults (14 men and 8 women) completed running and bicycling activity bouts (5 minutes each) while wearing 6 accelerometers: 2 each at the waist, thigh and shank. Accelerometer and video data were collected during activity. Excellent reliability and validity were found for measurements taken from accelerometers mounted at the waist and shank during running (Reliability: intraclass correlation (ICC) ≥ 0.99; standard error of measurement (SEM) ≤1.0 steps; Pearson ≥ 0.99) and at the thigh and shank during bicycling (Reliability: ICC ≥ 0.99; SEM ≤1.0 revolutions; Pearson ≥ 0.99). Excellent reliability was found between measurements taken at the waist and shank during running (ICC ≥ 0.98; SEM ≤1.6 steps) and between measurements taken at the thigh and shank during bicycling (ICC ≥ 0.99; SEM ≤1.0 revolutions). These data suggest that the GT3X+ can be used for measuring step-count during running and pedal-revolution count during bicycling. Only shank placement is recommended for both activities.

The effect of Q factor on gross mechanical efficiency and muscular activation in cycling.

PubMed

Disley, B X; Li, F-X

2014-02-01

Unexplored in scientific literature, Q Factor describes the horizontal width between bicycle pedals and determines where the foot is laterally positioned throughout the pedal stroke. The aim of the study was to determine whether changing Q Factor has a beneficial effect upon cycling efficiency and muscular activation. A total of 24 trained cyclists (11 men, 13 women; VO2max 57.5 ml·kg/min ± 6.1) pedaled at 60% of peak power output for 5 min at 90 rpm using Q Factors of 90, 120, 150, and 180 mm. Power output and gas were collected and muscular activity of the gastrocnemius medialis (GM), tibialis anterior (TA), vastus medialis (VM), and vastus lateralis (VL) measured using surface electromyography. There was a significant increase (P < 0.006) in gross mechanical efficiency (GME) for 90 and 120 mm (both 19.38%) compared with 150 and 180 mm (19.09% and 19.05%), representing an increase in external mechanical work performed of approximately 4-5 W (1.5-2.0%) at submaximal power outputs. There was no significant difference in the level of activity or timing of activation of the GM, TA, VM, and VL between Q Factors. Other muscles used in cycling, and possibly an improved application of force during the pedal stroke may play a role in the observed increase in GME with narrower Q Factors. © 2012 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Haptic Foot Pedal: Influence of Shoe Type, Age, and Gender on Subjective Pulse Perception.

PubMed

Geitner, Claudia; Birrell, Stewart; Krehl, Claudia; Jennings, Paul

2018-06-01

This study investigates the influence of shoe type (sneakers and safety boots), age, and gender on the perception of haptic pulse feedback provided by a prototype accelerator pedal in a running stationary vehicle. Haptic feedback can be a less distracting alternative to traditionally visual and auditory in-vehicle feedback. However, to be effective, the device delivering the haptic feedback needs to be in contact with the person. Factors such as shoe type vary naturally over the season and could render feedback that is perceived well in one situation, unnoticeable in another. In this study, we evaluate factors that can influence the subjective perception of haptic feedback in a stationary but running car: shoe type, age, and gender. Thirty-six drivers within three age groups (≤39, 40-59, and ≥60) took part. For each haptic feedback, participants rated intensity, urgency, and comfort via a questionnaire. The perception of the haptic feedback is significantly influenced by the interaction between the pulse's duration and force amplitude and the participant's age and gender but not shoe type. The results indicate that it is important to consider different age groups and gender in the evaluation of haptic feedback. Future research might also look into approaches to adapt haptic feedback to the individual driver's preferences. Findings from this study can be applied to the design of an accelerator pedal in a car, for example, for a nonvisual in-vehicle warning, but also to plan user studies with a haptic pedal in general.

In situ UV curable 3D printing of multi-material tri-legged soft bot with spider mimicked multi-step forward dynamic gait

NASA Astrophysics Data System (ADS)

Zeb Gul, Jahan; Yang, Bong-Su; Yang, Young Jin; Chang, Dong Eui; Choi, Kyung Hyun

2016-11-01

Soft bots have the expedient ability of adopting intricate postures and fitting in complex shapes compared to mechanical robots. This paper presents a unique in situ UV curing three-dimensional (3D) printed multi-material tri-legged soft bot with spider mimicked multi-step dynamic forward gait using commercial bio metal filament (BMF) as an actuator. The printed soft bot can produce controllable forward motion in response to external signals. The fundamental properties of BMF, including output force, contractions at different frequencies, initial loading rate, and displacement-rate are verified. The tri-pedal soft bot CAD model is designed inspired by spider’s legged structure and its locomotion is assessed by simulating strain and displacement using finite element analysis. A customized rotational multi-head 3D printing system assisted with multiple wavelength’s curing lasers is used for in situ fabrication of tri-pedal soft-bot using two flexible materials (epoxy and polyurethane) in three layered steps. The size of tri-pedal soft-bot is 80 mm in diameter and each pedal’s width and depth is 5 mm × 5 mm respectively. The maximum forward speed achieved is 2.7 mm s-1 @ 5 Hz with input voltage of 3 V and 250 mA on a smooth surface. The fabricated tri-pedal soft bot proved its power efficiency and controllable locomotion at three input signal frequencies (1, 2, 5 Hz).

Effects of working memory load and repeated scenario exposure on emergency braking performance.

PubMed

Engström, Johan; Aust, Mikael Ljung; Viström, Matias

2010-10-01

The objective of the present study was to examine the effect of working memory load on drivers' responses to a suddenly braking lead vehicle and whether this effect (if any) is moderated by repeated scenario exposure. Several experimental studies have found delayed braking responses to lead vehicle braking events during concurrent performance of nonvisual, working memory-loading tasks, such as hands-free phone conversation. However, the common use of repeated, and hence somewhat expected, braking events may undermine the generalizability of these results to naturalistic, unexpected, emergency braking scenarios. A critical lead vehicle braking scenario was implemented in a fixed-based simulator.The effects of working memory load and repeated scenario exposure on braking performance were examined. Brake response time was decomposed into accelerator pedal release time and accelerator-to-brake pedal movement time. Accelerator pedal release times were strongly reduced with repeated scenario exposure and were delayed by working memory load with a small but significant amount (178 ms).The two factors did not interact. There were no effects on accelerator-to-brake pedal movement time. The results suggest that effects of working memory load on response performance obtained from repeated critical lead vehicle braking scenarios may be validly generalized to real world unexpected events. The results have important implications for the interpretation of braking performance in experimental settings, in particular in the context of safety-related evaluation of in-vehicle information and communication technologies.

Noncontrast MRA of pedal arteries in type II diabetes: effect of disease load on vessel visibility.

PubMed

Zhang, Lijuan; Liu, Xin; Fan, Zhaoyang; Zhang, Na; Chung, Yiu-Cho; Liao, Weiqi; Zheng, Hairong; Li, Debiao

2015-04-01

Noncontrast magnetic resonance angiography (NC-MRA) of pedal artery remains challenging because of the global and regional disease load, tissue integrity, and altered microcirculation. This study aims to investigate the feasibility of the NC-MRA of pedal arteries with flow-sensitive dephasing-prepared steady-state free precession (FSD-SSFP) and to explore the effect of disease load of type II diabetes on the vessel depiction. FSD-SSFP was performed on a 1.5-T magnetic resonance system before the contrast-enhanced MRA (CE-MRA) as a reference standard in 39 consecutive diabetic subjects (29 men and 16 women, aged 57.9 ± 11.4 years). Two experienced radiologists evaluated the overall artery visibility (VA) and the contamination from soft tissue (SC) and veins (VC) with a four-point scale. Chronic complications and measures including random blood glucose (RBG), lipid panel, body mass index, risk of diabetic foot ulcers (RDF), and glycated hemoglobin (HbA1c) by the imaging were recorded as disease load indicators. Spearman rank correlation and ordinal regression were performed to investigate the effect of disease load on the depiction of pedal arteries. The measurement of RBG and RDF were significantly correlated with the VC in CE-MRA and with the overall visibility of pedal arteries in NC-MRA (P < .025 and P < .001, respectively). Blood pressure was the only parameter that was significantly associated with SC in NC-MRA with FSD-SSFP (P < .025). For CE-MRA the effect of RDF on the overall VA manifested a significant linear trend (P < .001), and the level of RBG was substantially associated with the VC (P < .025) without significantly impacting VA and SC. Hypertension only correlated with SC in NC-MRA. VA was found independent of the presence of diabetic nephropathy, coronary artery disease, abnormal lipid panel, HbA1c (75.0%), or optimized m1 value that ranged from 70 to 160 mT⋅ms(2)/m (mean, 125 ± 18 mT⋅ms(2)/m) in this study. FSD-SSFP proved to be a useful modality of NC-MRA for pedal artery imaging in diabetic patients. The vessel depiction is subject to the local and systemic disease load of type II diabetes. Technical optimization of the flow-sensitive dephasing gradient moment and properly choosing candidate would help augment the potential of this technique in patient care of peripheral artery disease. Copyright © 2015 AUR. Published by Elsevier Inc. All rights reserved.

Design of a novel, one-sided, pedal-activated wheelchair.

PubMed

Lin, T-Y; Hsiao, K-H; Yao, H-W

2011-07-01

The present paper proposes the design of a novel, one-sided, pedal-activated wheelchair for patients with hemiplegia or hemiparesis. The design comprises a planetary hub transmission, which is embedded in the hub of the wheelchair, with drive, neutral, and reverse modes. The paper first discusses the structural characteristics and motion transmission of the wheelchair, and then presents the motion design of the hub transmission, followed by assembly and testing of the prototype. The results confirm that the proposed wheelchair and hub transmission can meet users' demands, thus improving comfort and independence.

BrainCycles: Experimental Setup for the Combined Measurement of Cortical and Subcortical Activity in Parkinson's Disease Patients during Cycling.

PubMed

Gratkowski, Maciej; Storzer, Lena; Butz, Markus; Schnitzler, Alfons; Saupe, Dietmar; Dalal, Sarang S

2016-01-01

Recently, it has been demonstrated that bicycling ability remains surprisingly preserved in Parkinson's disease (PD) patients who suffer from freezing of gait. Cycling has been also proposed as a therapeutic means of treating PD symptoms, with some preliminary success. The neural mechanisms behind these phenomena are however not yet understood. One of the reasons is that the investigations of neuronal activity during pedaling have been up to now limited to PET and fMRI studies, which restrict the temporal resolution of analysis, and to scalp EEG focused on cortical activation. However, deeper brain structures like the basal ganglia are also associated with control of voluntary motor movements like cycling and are affected by PD. Deep brain stimulation (DBS) electrodes implanted for therapy in PD patients provide rare and unique access to directly record basal ganglia activity with a very high temporal resolution. In this paper we present an experimental setup allowing combined investigation of basal ganglia local field potentials (LFPs) and scalp EEG underlying bicycling in PD patients. The main part of the setup is a bike simulator consisting of a classic Dutch-style bicycle frame mounted on a commercially available ergometer. The pedal resistance is controllable in real-time by custom software and the pedal position is continuously tracked by custom Arduino-based electronics using optical and magnetic sensors. A portable bioamplifier records the pedal position signal, the angle of the knee, and the foot pressure together with EEG, EMG, and basal ganglia LFPs. A handlebar-mounted display provides additional information for patients riding the bike simulator, including the current and target pedaling rate. In order to demonstrate the utility of the setup, example data from pilot recordings are shown. The presented experimental setup provides means to directly record basal ganglia activity not only during cycling but also during other movement tasks in patients who have undergone DBS treatment. Thus, it can facilitate studies comparing bicycling and walking, to elucidate why PD patients often retain the ability to bicycle despite severe freezing of gait. Moreover it can help clarifying the mechanism through which cycling may have therapeutic benefits.

FES-assisted Cycling Improves Aerobic Capacity and Locomotor Function Postcerebrovascular Accident.

PubMed

Aaron, Stacey E; Vanderwerker, Catherine J; Embry, Aaron E; Newton, Jennifer H; Lee, Samuel C K; Gregory, Chris M

2018-03-01

After a cerebrovascular accident (CVA) aerobic deconditioning contributes to diminished physical function. Functional electrical stimulation (FES)-assisted cycling is a promising exercise paradigm designed to target both aerobic capacity and locomotor function. This pilot study aimed to evaluate the effects of an FES-assisted cycling intervention on aerobic capacity and locomotor function in individuals post-CVA. Eleven individuals with chronic (>6 months) post-CVA hemiparesis completed an 8-wk (three times per week; 24 sessions) progressive FES-assisted cycling intervention. V˙O2peak, self-selected, and fastest comfortable walking speeds, gait, and pedaling symmetry, 6-min walk test (6MWT), balance, dynamic gait movements, and health status were measured at baseline and posttraining. Functional electrical stimulation-assisted cycling significantly improved V˙O2peak (12%, P = 0.006), self-selected walking speed (SSWS, 0.05 ± 0.1 m·s, P = 0.04), Activities-specific Balance Confidence scale score (12.75 ± 17.4, P = 0.04), Berg Balance Scale score (3.91 ± 4.2, P = 0.016), Dynamic Gait Index score (1.64 ± 1.4, P = 0.016), and Stroke Impact Scale participation/role domain score (12.74 ± 16.7, P = 0.027). Additionally, pedal symmetry, represented by the paretic limb contribution to pedaling (paretic pedaling ratio [PPR]) significantly improved (10.09% ± 9.0%, P = 0.016). Although step length symmetry (paretic step ratio [PSR]) did improve, these changes were not statistically significant (-0.05% ± 0.1%, P = 0.09). Exploratory correlations showed moderate association between change in SSWS and 6-min walk test (r = 0.74), and moderate/strong negative association between change in PPR and PSR. These results support FES-assisted cycling as a means to improve both aerobic capacity and locomotor function. Improvements in SSWS, balance, dynamic walking movements, and participation in familial and societal roles are important targets for rehabilitation of individuals after CVA. Interestingly, the correlation between PSR and PPR suggests that improvements in pedaling symmetry may translate to a more symmetric gait pattern.

BrainCycles: Experimental Setup for the Combined Measurement of Cortical and Subcortical Activity in Parkinson's Disease Patients during Cycling

PubMed Central

Gratkowski, Maciej; Storzer, Lena; Butz, Markus; Schnitzler, Alfons; Saupe, Dietmar; Dalal, Sarang S.

2017-01-01

Recently, it has been demonstrated that bicycling ability remains surprisingly preserved in Parkinson's disease (PD) patients who suffer from freezing of gait. Cycling has been also proposed as a therapeutic means of treating PD symptoms, with some preliminary success. The neural mechanisms behind these phenomena are however not yet understood. One of the reasons is that the investigations of neuronal activity during pedaling have been up to now limited to PET and fMRI studies, which restrict the temporal resolution of analysis, and to scalp EEG focused on cortical activation. However, deeper brain structures like the basal ganglia are also associated with control of voluntary motor movements like cycling and are affected by PD. Deep brain stimulation (DBS) electrodes implanted for therapy in PD patients provide rare and unique access to directly record basal ganglia activity with a very high temporal resolution. In this paper we present an experimental setup allowing combined investigation of basal ganglia local field potentials (LFPs) and scalp EEG underlying bicycling in PD patients. The main part of the setup is a bike simulator consisting of a classic Dutch-style bicycle frame mounted on a commercially available ergometer. The pedal resistance is controllable in real-time by custom software and the pedal position is continuously tracked by custom Arduino-based electronics using optical and magnetic sensors. A portable bioamplifier records the pedal position signal, the angle of the knee, and the foot pressure together with EEG, EMG, and basal ganglia LFPs. A handlebar-mounted display provides additional information for patients riding the bike simulator, including the current and target pedaling rate. In order to demonstrate the utility of the setup, example data from pilot recordings are shown. The presented experimental setup provides means to directly record basal ganglia activity not only during cycling but also during other movement tasks in patients who have undergone DBS treatment. Thus, it can facilitate studies comparing bicycling and walking, to elucidate why PD patients often retain the ability to bicycle despite severe freezing of gait. Moreover it can help clarifying the mechanism through which cycling may have therapeutic benefits. PMID:28119591

Cognitive effects of rhythmic auditory stimulation in Parkinson's disease: A P300 study.

PubMed

Lei, Juan; Conradi, Nadine; Abel, Cornelius; Frisch, Stefan; Brodski-Guerniero, Alla; Hildner, Marcel; Kell, Christian A; Kaiser, Jochen; Schmidt-Kassow, Maren

2018-05-16

Rhythmic auditory stimulation (RAS) may compensate dysfunctions of the basal ganglia (BG), involved with intrinsic evaluation of temporal intervals and action initiation or continuation. In the cognitive domain, RAS containing periodically presented tones facilitates young healthy participants' attention allocation to anticipated time points, indicated by better performance and larger P300 amplitudes to periodic compared to random stimuli. Additionally, active auditory-motor synchronization (AMS) leads to a more precise temporal encoding of stimuli via embodied timing encoding than stimulus presentation adapted to the participants' actual movements. Here we investigated the effect of RAS and AMS in Parkinson's disease (PD). 23 PD patients and 23 healthy age-matched controls underwent an auditory oddball task. We manipulated the timing (periodic/random/adaptive) and setting (pedaling/sitting still) of stimulation. While patients elicited a general timing effect, i.e., larger P300 amplitudes for periodic versus random tones for both, sitting and pedaling conditions, controls showed a timing effect only for the sitting but not for the pedaling condition. However, a correlation between P300 amplitudes and motor variability in the periodic pedaling condition was obtained in control participants only. We conclude that RAS facilitates attentional processing of temporally predictable external events in PD patients as well as healthy controls, but embodied timing encoding via body movement does not affect stimulus processing due to BG impairment in patients. Moreover, even with intact embodied timing encoding, such as healthy elderly, the effect of AMS depends on the degree of movement synchronization performance, which is very low in the current study. Copyright © 2018 Elsevier B.V. All rights reserved.

Intra-session repeatability of lower limb muscles activation pattern during pedaling.

PubMed

Dorel, Sylvain; Couturier, Antoine; Hug, François

2008-10-01

Assessment of intra-session repeatability of muscle activation pattern is of considerable relevance for research settings, especially when used to determine changes over time. However, the repeatability of lower limb muscles activation pattern during pedaling is not fully established. Thus, we tested the intra-session repeatability of the activation pattern of 10 lower limb muscles during a sub-maximal cycling exercise. Eleven triathletes participated to this study. The experimental session consisted in a reference sub-maximal cycling exercise (i.e. 150 W) performed before and after a 53-min simulated training session (mean power output=200+/-12 W). Repeatability of EMG patterns was assessed in terms of muscle activity level (i.e. RMS of the mean pedaling cycle and burst) and muscle activation timing (i.e. onset and offset of the EMG burst) for the 10 following lower limb muscles: gluteus maximus (GMax), semimembranosus (SM), Biceps femoris (BF), vastus medialis (VM), rectus femoris (RF), vastus lateralis (VL), gastrocnemius medianus (GM) and lateralis (GL), soleus (SOL) and tibialis anterior (TA). No significant differences concerning the muscle activation level were found between test and retest for all the muscles investigated. Only VM, SOL and TA showed significant differences in muscle activation timing parameters. Whereas ICC and SEM values confirmed this weak repeatability, cross-correlation coefficients suggest a good repeatability of the activation timing parameters for all the studied muscles. Overall, the main finding of this work is the good repeatability of the EMG pattern during pedaling both in term of muscle activity level and muscle activation timing.

Muscle coordination limits efficiency and power output of human limb movement under a wide range of mechanical demands

PubMed Central

Wakeling, James M.

2015-01-01

This study investigated the influence of cycle frequency and workload on muscle coordination and the ensuing relationship with mechanical efficiency and power output of human limb movement. Eleven trained cyclists completed an array of cycle frequency (cadence)-power output conditions while excitation from 10 leg muscles and power output were recorded. Mechanical efficiency was maximized at increasing cadences for increasing power outputs and corresponded to muscle coordination and muscle fiber type recruitment that minimized both the total muscle excitation across all muscles and the ineffective pedal forces. Also, maximum efficiency was characterized by muscle coordination at the top and bottom of the pedal cycle and progressive excitation through the uniarticulate knee, hip, and ankle muscles. Inefficiencies were characterized by excessive excitation of biarticulate muscles and larger duty cycles. Power output and efficiency were limited by the duration of muscle excitation beyond a critical cadence (120–140 rpm), with larger duty cycles and disproportionate increases in muscle excitation suggesting deteriorating muscle coordination and limitations of the activation-deactivation capabilities. Most muscles displayed systematic phase shifts of the muscle excitation relative to the pedal cycle that were dependent on cadence and, to a lesser extent, power output. Phase shifts were different for each muscle, thereby altering their mechanical contribution to the pedaling action. This study shows that muscle coordination is a key determinant of mechanical efficiency and power output of limb movement across a wide range of mechanical demands and that the excitation and coordination of the muscles is limited at very high cycle frequencies. PMID:26445873

Effect of sprint training: training once daily versus twice every second day.

PubMed

Ijichi, Toshiaki; Hasegawa, Yuta; Morishima, Takuma; Kurihara, Toshiyuki; Hamaoka, Takafumi; Goto, Kazushige

2015-01-01

This study compared training adaptations between once daily (SINGLE) and twice every second day (REPEATED) sprint training, with same number of training sessions. Twenty physically active males (20.9 ± 1.3 yr) were assigned randomly to the SINGLE (n = 10) or REPEATED (n = 10) group. The SINGLE group trained once per day (5 days per week) for 4 weeks (20 sessions in total). The REPEATED group conducted two consecutive training sessions on the same day, separated by a rest period of 1 h (2-3 days per week) for 4 weeks (20 sessions in total). Each training session consisted of three consecutive 30-s maximal pedalling sets with a 10-min rest between sets. Before and after the training period, the power output during two bouts of 30-s maximal pedalling, exercise duration during submaximal pedalling and resting muscle phosphocreatine (PCr) levels were evaluated. Both groups showed significant increases in peak and mean power output during the two 30-s bouts of maximal pedalling after the training period (P < 0.05). The groups showed similar increases in VO2max after the training period (P < 0.05). The REPEATED group showed a significant increase in the onset of blood lactate accumulation (OBLA) after the training period (P < 0.05), whereas no change was observed in the SINGLE group. The time to exhaustion at 90% of VO2max and muscle PCr concentration at baseline did not change significantly in either group. Sprint training twice every second day improved OBLA during endurance exercise more than the same training once daily.

The Effects of Wearing High Heels while Pressing a Car Accelerator Pedal on Lower Extremity Muscle Activation

PubMed Central

Jung, Jaemin; Lee, Sang-yeol

2014-01-01

[Purpose] The purpose of this study was to determine the effects of wearing high heels while driving on lower extremity muscle activation. [Subjects] The subjects of this experimental study were 14 healthy women in their 20s who normally wear shoes with high heels. [Methods] The subjects were asked to place their shoes on an accelerator pedal with the heel touching the floor and then asked to press the pedal with as much pressure as possible for 3 seconds before removing their feet from the pedal. A total of 3 measurements were taken for each heel height (flat, 5 cm, 7 cm), and the heel height was randomly selected. [Results] The levels of muscle activity, indicated as the percentage of reference voluntary contraction, for gastrocnemius muscle in the flat, 5 cm, and 7 cm shoes were 180.8±61.8%, 285.4±122.3%, and 366.2±193.7%, respectively, and there were significant differences between groups. Those for the soleus muscle were 477.3±209.2%, 718.8±380.5%, and 882.4±509.9%, and there were significant differences between groups. [Conclusion] To summarize the results of this study, it was found that female drivers require greater lower extremity muscle activation when wearing high heels than when wearing low heels. Furthermore, instability and muscle fatigue of the ankle joint, which results from wearing high heels on a daily basis, could also occur while driving. PMID:25435684

Pedal proportions of Poposaurus gracilis: convergence and divergence in the feet of archosaurs.

PubMed

Farlow, James O; Schachner, Emma R; Sarrazin, John Cody; Klein, Hendrik; Currie, Philip J

2014-06-01

The crocodile-line basal suchian Poposaurus gracilis had body proportions suggesting that it was an erect, bipedal form like many dinosaurs, prompting questions of whether its pedal proportions, and the shape of its footprint, would likewise "mimic" those of bipedal dinosaurs. We addressed these questions through a comparison of phalangeal, digital, and metatarsal proportions of Poposaurus with those of extinct and extant crocodile-line archosaurs, obligate or facultatively bipedal non-avian dinosaurs, and ground birds of several clades, as well as a comparison of the footprint reconstructed from the foot skeleton of Poposaurus with known early Mesozoic archosaurian ichnotaxa. Bivariate and multivariate analyses of phalangeal and digital dimensions showed numerous instances of convergence in pedal morphology among disparate archosaurian clades. Overall, the foot of Poposaurus is indeed more like that of bipedal dinosaurs than other archosaur groups, but is not exactly like the foot of any particular bipedal dinosaur clade. Poposaurus likely had a digitigrade stance, and its footprint shape could have resembled grallatorid ichnotaxa, unless digit I of the foot of Poposaurus commonly left an impression. Copyright © 2014 Wiley Periodicals, Inc.

Changes in male foot shape and size with weightbearing.

PubMed

Houston, Vern L; Luo, Gangming; Mason, Carl P; Mussman, Martin; Garbarini, Maryanne; Beattie, Aaron C

2006-01-01

Accurate, consistent measurement of foot-ankle geometry is essential for the design and manufacture of well-fitting, functional, comfortable footwear; for the diagnosis of certain biomechanical disorders; and for consistent longitudinal monitoring and assessment of pedorthic treatment outcomes. We sought to formulate a basic set of measures characterizing the principal geometric dimensions of the foot, to investigate how these measures vary with increasing weightbearing, and to explore the implications of weightbearing changes in pedal geometry for orthopedic footwear design and manufacture. The right feet of 40 healthy men aged 22 to 71 years were scanned using the Department of Veterans Affairs Pedorthics Optical Digitizer in neutral alignment, sequentially bearing 0%, 10%, 25%, 50%, and 100% of the subjects' body weight. With support of the full body weight, the following mean changes in the pedal parameters were observed: heel-to-toe length, 1.5%; ball width, 4.3%; maximum heel width, 4.8%; and instep height, -9.3%. On average, 71% of the changes sustained in the pedal parameters at full weightbearing occurred when, or before, 25% of the body weight was applied.

Footprints in the sand: independent reduction of subdigital lamellae in the Namib-Kalahari burrowing geckos.

PubMed

Lamb, Trip; Bauer, Aaron M

2006-04-07

Many desert organisms exhibit convergence, and certain physical factors such as windblown sands have generated remarkably similar ecomorphs across divergent lineages. The burrowing geckos Colopus, Chondrodactylus and Palmatogecko occupy dune ecosystems in the Namib and Kalahari deserts of southwest Africa. Considered closely related, they share several putative synapomorphies, including reduced subdigital pads (toe pads) and spinose digital scales. Though recognized as part of Africa's ecologically diverse Pachydactylus Group, the burrowing geckos' precise phylogenetic affinities remain elusive. Convergent pedal modification provides a tenable alternative explaining the geckos' derived terrestriality and adaptation to Namib and Kalahari sands. We generated a molecular phylogeny for the Pachydactylus Group to examine evolutionary relationships among the burrowing geckos and infer historical patterns of pedal character change. Bayesian and parsimony analyses revealed all three burrowing genera to be deeply nested within Pachydactylus, each genus belonging to a separate clade. Strong support for these distinct clades indicates ecomorphological adaptations for burrowing have evolved independently three times in the southern Pachydactylus Group. We argue that the physical properties of Namib and Kalahari sands played a principal role in selecting for pedal similarity.

3D DCE-MRA of pedal arteries in patients with diabetes mellitus

NASA Astrophysics Data System (ADS)

Zamyshevskaya, M.; Zavadovskaya, V.; Zorkaltsev, M.; Udodov, V.; Grigorev, E.

2016-02-01

Purpose was identification and evaluation of pedal vascularization in diabetic patients of using contrast MR-angiography (3D DCE-MRA). 23 diabetic feet of 23 patients (15 male, 8 female; mean age 56 ± 14.6) underwent 3D DCE-MRA (Gadobutrol 15ml) at 1.5 T. Imaging analysis included blood-flow's speed, vascular architectonic's condition and character of contrast's accumulation. Osteomyelitis was verified by surgery in 15 cases. All patients were divided in 3 groups: neuropathic, neuroischemic, ischemic forms of diabetic foot. First- pass MRA detected significant delay of contrast's arrival in ischemic group. There were no significant differences between the values of neuropathic and neuroischemic forms of diabetic foot. Pedal vessels in patients were absent. Contrast MRA revealed three types of contrast distribution in soft tissues: uniform, local increase and local absence. Osteomyelitis was associated with diffuse enhanced contrast accumulation in all cases. In summary, MRI blood vessel imaging is a promising and valuable method for examining peripheral arterial changes in diabetic foot and might be useful for treatment planning in different forms of diabetic foot.

Biomechanics of knee rehabilitation with cycling.

PubMed

McLeod, W D; Blackburn, T A

1980-01-01

The bicycle provides quadriceps rehabilitation while controlling the stresses to the knee ligaments. With pedaling on the bicycle, forces are applied to the anterior cruciate ligament, the capsular ligaments, and the posterior structures of the knee joint as the tibial plateau is posteriorly tilted. The knee muscles can modify their forces. Therefore, by controlling the mode of cycling with varying seat heights and pedal positions, the ligaments can be relieved from these forces during the initial stages of the rehabilitative process. An exercise program can then be designed to apply controlled stress to these structures to enhance the healing and recovery processes.

Engineers test STS-37 CETA electrical hand pedal cart in JSC MAIL Bldg 9A

NASA Technical Reports Server (NTRS)

1990-01-01

McDonnell Douglas engineers Noland Talley (left) and Gary Peters (center) and ILC-Dover engineer Richard Richard Smallcombe prepare test setup for the evaluation of the crew and equipment translation aid (CETA) electrical hand pedal cart in JSC's Mockup and Integration Laboratory (MAIL) Bldg 9A. Peters, wearing extravehicular mobility unit (EMU) boots and positioned in portable foot restraint (PFR), is suspended above CETA cart and track via harness to simulate weightlessness. CETA will be tested in orbit in the payload bay of Atlantis, Orbiter Vehicle (OV) 104, during STS-37.

The Navy Medical Department’s Workload Management System for Nursing (Patient Classification and Staffing Allocation). Self-Instructional Workbook

DTIC Science & Technology

1986-01-01

minal area, assess fetal heart tones with stethoscope , record FHTs, and remove equipment from area. or . Fetal Heart Tones, Doppler: Includes time to...activity to total 4 points. 5. Femoral OR pedal pulses OR fetal heart tones must be taken q 4 h . before you count the 2 points, but once again, since the... fetal heart tones OR tilt tests will count 2 points each if doneq 4 h or more frequently. If you had a patient with pedal pulses q 4 h AND fetal heart

ROBIL - Robot Israel

DTIC Science & Technology

2013-07-31

pedals and releasing the hand brake ), the ROS ’actionlib’ is started. Atlas starts driving to the received way points until it reaches the last gate...grip at angle 0………………………………………………………………… ..31 FIGURE 3.5.6: MATLAB ’Steering wheel angle ’ output membership function schematic……………...……31...repeatability of the motion sequence. We added an optional motion to press the gas pedal at the end of the sequence in order to secure additional points

Outcomes of tibial endovascular intervention in patients with poor pedal runoff.

PubMed

Baer-Bositis, Hallie E; Hicks, Taylor D; Haidar, Georges M; Sideman, Matthew J; Pounds, Lori L; Davies, Mark G

2018-06-01

Tibial interventions for critical limb ischemia are now commonplace. The aim of this study was to examine the impact of pedal runoff on patient-centered outcomes after tibial endovascular intervention. A database of patients undergoing lower extremity endovascular interventions at a single urban academic medical center between 2006 and 2016 was retrospectively queried. Patients with critical ischemia (Rutherford 5 and 6) were identified. Preintervention angiograms were reviewed in all cases to assess pedal runoff. Each dorsalis pedis, lateral plantar, and medial plantar artery was assigned a score according to the reporting standards of the Society for Vascular Surgery (0, no stenosis >20%; 1, 21%-49% stenosis; 2, 50%-99% stenosis; 2.5, half or less of the vessel length occluded; 3, more than half the vessel length occluded). A foot score (dorsalis pedis + medial plantar + lateral plantar + 1) was calculated for each foot (1-10). Two runoff score groups were identified: good vs poor, <7 and ≥7, respectively. Patient-oriented outcomes of clinical efficacy (absence of recurrent symptoms, maintenance of ambulation, and absence of major amputation), amputation-free survival (survival without major amputation), and freedom from major adverse limb events (above-ankle amputation of the index limb or major reintervention [new bypass graft, jump/interposition graft revision]) were evaluated. There were 1134 patients (56% male; average age, 59 years) who underwent tibial intervention for critical ischemia, with a mean of two vessels treated per patient and a mean pedal runoff score of 6 (47% had a runoff score ≥7). Overall major adverse cardiac events were equivalent at 30 days after the procedure in both groups. At 5 years, vessels with compromised runoff (score ≥7) had significantly lower ulcer healing (25% ± 3% vs 73% ± 4%, mean ± standard error of the mean [SEM]) and a lower 5-year limb salvage rate (45% ± 6% vs 69% ± 4%, mean ± SEM) compared with those with good runoff (score <7). Patients with poor pedal runoff (score ≥7) had significantly lower clinical efficacy (23% ± 8% vs 38% ± 4%, mean ± SEM), amputation-free survival (32% ± 6% vs 48% ± 5%, mean ± SEM), and freedom from major adverse limb events (23% ± 9% vs 41% ± 8%, mean ± SEM) at 5 years compared with patients with good runoff (score <7). Pedal runoff score can identify those patients who will not achieve ulcer healing and patient-centered outcomes after tibial intervention. Defining such subgroups will allow stratification of the patients and appropriate application of interventions. Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Asymmetrical Pedaling Patterns in Parkinson's Disease Patients

PubMed Central

Penko, Amanda L.; Hirsch, Joshua R.; Voelcker-Rehage, Claudia; Martin, Philip E.; Blackburn, Gordon; Alberts, Jay L.

2015-01-01

Background Approximately 1.5 million Americans are affected by Parkinson's disease [1] which includes the symptoms of postural instability and gait dysfunction. Currently, clinical evaluations of postural instability and gait dysfunction consist of a subjective rater assessment of gait patterns using items from the Unified Parkinson's Disease Rating Scale, and assessments can be insensitive to the effectiveness of medical interventions. Current research suggests the importance of cycling for Parkinson's disease patients, and while Parkinson's gait has been evaluated in previous studies, little is known about lower extremity control during cycling. The purpose of this study is to examine the lower extremity coordination patterns of Parkinson's patients during cycling. Methods Twenty five participants, ages 44-72, with a clinical diagnosis of idiopathic Parkinson's disease participated in an exercise test on a cycle ergometer that was equipped with pedal force measurements. Crank torque, crank angle and power produced by right and left leg were measured throughout the test to calculate Symmetry Index at three stages of exercise (20 Watt, 60 Watt, maximum performance). Findings Decreases in Symmetry Index were observed for average power output in Parkinson's patients as workload increased. Maximum power Symmetry Index showed a significant difference in symmetry between performance at both the 20 Watt and 60 Watt stage and the maximal resistance stage. Minimum power Symmetry Index did not show significant differences across the stages of the test. While lower extremity asymmetries were present in Parkinson's patients during pedaling, these asymmetries did not correlate to postural instability and gait dysfunction Unified Parkinson's Disease Rating Scale scores. Interpretation This pedaling analysis allows for a more sensitive measure of lower extremity function than the Unified Parkinson's Disease Rating Scale and may help to provide unique insight into current and future lower extremity function. PMID:25467810

Heterogeneity of muscle recruitment pattern during pedaling in professional road cyclists: a magnetic resonance imaging and electromyography study.

PubMed

Hug, François; Bendahan, David; Le Fur, Yann; Cozzone, Patrick J; Grélot, Laurent

2004-07-01

Although a number of studies have been devoted to the analysis of the activity pattern of the muscles involved in pedaling in sedentary subjects and/or amateur cyclists, data on professional cyclists are scarce and the issue of inter-individual differences has never been addressed in detail. In the present series of experiments, we performed a non-invasive investigation using functional magnetic resonance imaging and surface electromyography to determine the pattern of activity of lower limb muscles during two different exhausting pedaling exercises in eight French professional cyclists. Each subject performed an incremental exercise during which electromyographic activity of eight lower limb muscles and respiratory variables were recorded. After a 3-h recovery period, transverse relaxation times (T2) were measured before and just after a standardized constant-load maximal exercise in order to quantify exercise-related T2 changes. The global EMG activity illustrated by the root mean square clearly showed a large inter-individual difference during the incremental exercise regardless of the investigated muscle (variation coefficient up to 81%). In addition, for most of the muscles investigated, the constant-load exercise induced T2 increases, which varied noticeably among the subjects. This high level of variation in the recruitment of lower limb muscles in professional cyclists during both incremental and constant-load exercises is surprising given the homogeneity related to maximal oxygen consumption and training volume. The high degree of expertise of these professional cyclists was not linked to the production of a common pattern of pedaling and our results provide an additional evidence that the nervous system has multiple ways of accomplishing a given motor task, as has been suggested previously by neural control theorists and experimentalists.

The often overlooked digital tuft: clues to diagnosis and pathophysiology of neuropathic disease and spondyloarthropathy

PubMed Central

Rothschild, B; Behnam, S

2005-01-01

Objective: To assess diagnostic implications of abnormalities of the pedal digital tufts and to identify features to facilitate distinguishing of spondyloarthropathy and leprosy. Background: Better criteria for distinguishing between these disorders are necessary if their character, natural history, and evolution are to be understood. Methods: Pedal x rays of 91 consecutive patients with diabetes, 21 alcoholic patients, 100 with spondyloarthropathy, 8 with scleroderma, and 137 with leprosy, and 188 defleshed skeletons of individuals with alcoholism, syphilis, cerebrovascular disease, and paraplegia from the Terry and Hamman-Todd collections were examined for evidence of osseous and articular pathologies. Digital tuft abnormalities were divided into irregularity, divot, flattening, resorption, whittling, and fragmentation. Results: Tuft divots were more common in alcoholics than in diabetic, and were more common in both than in the other groups studied. Tuft flattening was limited to alcoholic and neurosyphilis groups. Tuft whittling was especially prominent among individuals with spondyloarthropathy, contrasted with leprosy and diabetes. Aligned fractures were more common in diabetics than individuals with leprosy. Misaligned fractures were limited to individuals with leprosy and neurosyphilis. Leprosy and spondyloarthropathy were complicated by phalangeal and metatarsal whittling more commonly than other diseases studied. Background pedal abnormalities, derived from individuals with cardiovascular syphilis, cerebrovascular accidents, and paraplegia, was limited to abnormal divots only. Conclusions: Pedal digital tufts undergo a variety of pathological alterations useful in the recognition of disorders traditionally considered neuropathic in aetiology and in distinguishing differential considerations. Tuft flattening appears specific for alcoholism and neurosyphilis, and misaligned fractures seem specific for neurosyphilis and leprosy, providing differential assistance related to spondyloarthropathy. Conversely, periosteal reaction distinguishes spondyloarthropathy from leprosy. PMID:15647437

Strategies adopted by younger and older adults while operating a non-pedal tricycle.

PubMed

Calve, Tatiane; Russo Júnior, Douglas Vicente; Barela, Ana Maria Forti

Exercises that could prevent gait impairment of older adults should be implemented in such a way that practitioners can keep motivation and adherence independent of older adults fitness levels. This study describes how younger and older adults use a non-pedal tricycle to transport their bodies along a pathway. Nine younger (24±4.9y) and nine older (66±4.0y) adults participated in this study. They moved along a straight pathway at a self-selected comfortable speed with reflective markers on their main lower limb landmarks. A computerized gait analysis system with infrared cameras was used to obtain kinematic data to calculate spatial-temporal parameters and lower limb angles. Overall, participants from both groups were able to perform the task moving at a similar mean speed, with similar stride length and ankle joint excursion. Older adults had higher cadence (mean difference of 17steps/min; 95% CI=0.99-1.15) and hip excursion (mean difference of 12°; 95% CI=28-33), longer stance duration (mean difference of 3.4%; 95% CI=56.2-59.5), and lower knee excursion (mean difference of 6°; 95% CI=47.9-53.8) than younger adults. Older adults were able to transport their body with a non-pedal tricycle with more hip and less knee excursion than younger adults. Professionals that work with the older population should look at and take into consideration the use of non-pedal tricycles in exercise protocols and investigate the long-term impacts. Copyright © 2017 Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia. Publicado por Elsevier Editora Ltda. All rights reserved.

Hyperventilation as a strategy for improved repeated sprint performance.

PubMed

Sakamoto, Akihiro; Naito, Hisashi; Chow, Chin-Moi

2014-04-01

Repeated high-intensity sprints incur substantial anaerobic metabolic challenges and create an acidic muscle milieu that is unfavorable for subsequent performance. Hyperventilation, resulting in respiratory alkalosis, acts as a compensatory mechanism for metabolic acidosis. This study tested the hypothesis that hyperventilation performed during recovery intervals would attenuate performance decrement in repeated sprint pedaling. Thirteen male university athletes performed 10 sets of 10-second maximal pedaling on a cycle ergometer with a 60-second recovery between sets under control (spontaneous breathing) and hyperventilation conditions in a crossover counter-balanced manner. Pedaling load was set at 0.075 × body mass. Peak and mean power outputs were documented for each set to compare performance decrements for 10 sets between conditions. Hyperventilation (60 breaths per minute and end-tidal partial pressure of CO2 maintained at 20-25 mm Hg) was performed 30 seconds before each sprint set. This intervention successfully increased blood pH by 0.03-0.07 but lowered P(CO2) by 1.2-8.4 mm Hg throughout exercise (p < 0.001). The peak and mean power outputs, and blood [La] accumulation were not significantly different between the conditions. However, a significant condition × time interaction existed for peak power (p = 0.035) and mean power (p = 0.023), demonstrating an attenuation in power decrement in later sprint sets with hyperventilation. In conclusion, hyperventilation implemented during recovery intervals of repeated sprint pedaling attenuated performance decrements in later exercise bouts that was associated with substantial metabolic acidosis. The practical implication is that hyperventilation may have a strategic role for enhancing training effectiveness and may give an edge in performance outcomes.

Integrated inertial sensors and mobile computing for real-time cycling performance guidance via pedaling profile classification.

PubMed

Xu, James Y; Nan, Xiaomeng; Ebken, Victor; Wang, Yan; Pottie, Greg J; Kaiser, William J

2015-03-01

Today, the bicycle is utilized as a daily commute tool, a physical rehabilitation asset, and sporting equipment, prompting studies into the biomechanics of cycling. Of the number of important parameters that affect cycling efficiency, the foot angle profile is one of the most important as it correlates directly with the effective force applied to the bike. However, there has been no compact and portable solution for measuring the foot angle and for providing the cyclist with real-time feedback due to a number of difficulties of the current tracking and sensing technologies and the myriad types of bikes available. This paper presents a novel sensing and mobile computing system for classifying the foot angle profiles during cycling and for providing real-time guidance to the user to achieve the correct profile. Continuous foot angle tracking is firstly converted into a discrete problem requiring only recognition of acceleration profiles of the foot using a single shoe mounted tri-axial accelerometer during each pedaling cycle. A classification method is then applied to identify the pedaling profile. Finally, a mobile solution is presented to provide real-time signal processing and guidance.

Footprints in the sand: independent reduction of subdigital lamellae in the Namib–Kalahari burrowing geckos

PubMed Central

Lamb, Trip; Bauer, Aaron M

2005-01-01

Many desert organisms exhibit convergence, and certain physical factors such as windblown sands have generated remarkably similar ecomorphs across divergent lineages. The burrowing geckos Colopus, Chondrodactylus and Palmatogecko occupy dune ecosystems in the Namib and Kalahari deserts of southwest Africa. Considered closely related, they share several putative synapomorphies, including reduced subdigital pads (toe pads) and spinose digital scales. Though recognized as part of Africa's ecologically diverse Pachydactylus Group, the burrowing geckos' precise phylogenetic affinities remain elusive. Convergent pedal modification provides a tenable alternative explaining the geckos' derived terrestriality and adaptation to Namib and Kalahari sands. We generated a molecular phylogeny for the Pachydactylus Group to examine evolutionary relationships among the burrowing geckos and infer historical patterns of pedal character change. Bayesian and parsimony analyses revealed all three burrowing genera to be deeply nested within Pachydactylus, each genus belonging to a separate clade. Strong support for these distinct clades indicates ecomorphological adaptations for burrowing have evolved independently three times in the southern Pachydactylus Group. We argue that the physical properties of Namib and Kalahari sands played a principal role in selecting for pedal similarity. PMID:16618680

Central representation of sensory inputs from the cardio-renal system in Aplysia depilans.

PubMed

Rózsa, K S; Salánki, J; Véró, M; Kovacević, N; Konjevic, D

1980-01-01

Studying the central representation of sensory inputs originating from the heart in Aplysia depilans, it was found that: 1. Neurons responding to heart stimulation can be found in the abdominal, pedal and pleural ganglia alike. 2. The representation of heart input signals was more abundant in the left hemisphere of the abdominal ganglion and in the left pedal and pleural ganglia. 3. The giant neurons of Aplysia depilans can be compared to the homologous cells of Aplysia californica. Two motoneurons (RBHE, LDHI) and one interneuron (L10) proved to be identical in the two subspecies. 4. Sensory inputs originating from the heart may modify the pattern of both heart regulatory motoneurons and interneurons. 5. Nine giant and 19 small neurons of the abdominal ganglion, 3--3 neurons of the right and left pleural ganglion, 6 neurons of the left pedal ganglion responded to heart stimulation. 6. The bursting patterns of cells R15 and L4 were modified to tonic discharge in response to heart stimulation. 7. The representation of sensory inputs originating from the heart is scattered throughout the CNS of Aplysia depilans and heart regulation is based on a feedback mechanism similar to that found in other gastropod species.

Foot pedal operated fluid type exercising device

NASA Technical Reports Server (NTRS)

Crum, G. W.; Sauter, R. J. (Inventor)

1973-01-01

A foot pedal operated exercising device is reported that contains a dynamometer formed of a pair of cylinders each containing a piston. The pistons are linked to each other. The upper portions of the two cylinders are joined together by a common opening to provide a common fluid reservoir and each piston is provided with a one way check valve to maintain an adequate supply of working fluid. Fluid from the driven cylinder is transmitted to the other cylinder through separate constant force spring biased valves each valve takes the predominant portion of the pressure drop thereby providing a constant force hydraulic dynamometer. A device is provided to determine the amount of movement of piston travel.

Muscle Feasibility for Cosmos Rhesus

NASA Technical Reports Server (NTRS)

Edgerton, V. Reggie (Principal Investigator); Roland, Roy R.; Hodgson, John A.

1994-01-01

The following tasks were proposed for the Cosmos project: 1) Complete recordings of all preflight candidates during performance of a foot pedal motor control task while in the space capsule mock-up. 2) Complete recordings of all preflight candidates during locomotion and postural tasks. 3) Complete recordings of 24-hour spontaneous cage activity in the two flight monkeys before and after flight and of at least three control (non-flight) monkeys after the flight has been completed. 4) Complete recordings of the foot pedal and motor control tasks during flight and postflight as scheduled. 5) Complete recordings of the vertical drop test pre, during and postflight for the two flight and three control monkeys. 6) Complete recordings of locomotion and posture tests of the two flight monkeys postflight. 7) Complete recordings of locomotion and postural tests of at least three control (non-flight) monkeys during the postflight period. 8) Recalibrate buckles of the two flight and of at least three control monkeys postflight. 9) Complete analysis of the 24 hour EMG recordings of all monkeys. 10) Complete analysis of the foot pedal, locomotor and postural motor control tasks for the two flight and three control monkeys. It was proposed that efforts in the first postflight year be concentrated on the two flight animals and three postflight animals.

Cycling induced by electrical stimulation improves muscle activation and symmetry during pedaling in hemiparetic patients.

PubMed

Ambrosini, Emilia; Ferrante, Simona; Ferrigno, Giancarlo; Molteni, Franco; Pedrocchi, Alessandra

2012-05-01

A randomized controlled trial, involving 35 post-acute hemiparetic patients, demonstrated that a four-week treatment of cycling induced by functional electrical stimulation (FES-cycling) promotes motor recovery. Analyzing additional data acquired during that study, the present work investigated whether these improvements were associated to changes in muscle strength and motor coordination. Participants were randomized to receive FES-cycling or placebo FES-cycling. Clinical outcome measures were: the Motricity Index (MI), the gait speed, the electromyography activation of the rectus femoris and biceps femoris, and the mechanical work produced by each leg during voluntary pedaling. To provide a comparison with normal values, healthy adults also carried out the pedaling test. Patients were evaluated before, after training, and at follow-up visits. A significant treatment effect in favor of FES-treated patients was found in terms of MI scores and unbalance in mechanical works, while differences in gait speed were not significant (ANCOVA). Significant improvements in the activation of the paretic muscles were highlighted in the FES group, while no significant change was found in the placebo group (Friedman test). Our findings suggested that improvements in motor functions induced by FES-cycling training were associated with a more symmetrical involvement of the two legs and an improved motor coordination.

A method to determine the kinematics of the lower limbs of a subject pedaling a bicycle using encoders and accelerometers. M.S. Thesis

NASA Technical Reports Server (NTRS)

Liu, Shih-Ching

1994-01-01

The goal of this research was to determine kinematic parameters of the lower limbs of a subject pedaling a bicycle. An existing measurement system was used as the basis to develop the model to determine position and acceleration of the limbs. The system consists of an ergometer instrumented to provide position of the pedal (foot), accelerometers to be attached to the lower limbs to measure accelerations, a recorder used for filtering, and a computer instrumented with an A/D board and a decoder board. The system is designed to read and record data from accelerometers and encoders. Software has been developed for data collection, analysis and presentation. Based on the measurement system, a two dimensional analytical model has been developed to determine configuration (position, orientation) and kinematics (velocities, accelerations). The model has been implemented in software and verified by simulation. An error analysis to determine the system's accuracy shows that the expected error is well within the specifications of practical applications. When the physical hardware is completed, NASA researchers hope to use the system developed to determine forces exerted by muscles and forces at articulations. This data will be useful in the development of countermeasures to minimize bone loss experienced by astronauts in microgravity conditions.

Biology of a deep-water sea anemone (Anthozoa: Actiniidae) from eastern Canada: Spawning, development, and growth

NASA Astrophysics Data System (ADS)

Mercier, Annie; Baillon, Sandrine; Daly, Marymegan; Macrander, Jason; Hamel, Jean-François

2017-03-01

Knowledge of the general biology and reproductive ecology of deep-water species can help predict their resilience to environmental and anthropogenic disturbances. The present study centers on live specimens of a deep-water sea anemone which were collected at bathyal depths between 1100 and 1400 m and kept in a mesocosm for over 6 years. Morphology and DNA sequencing confirmed that the species belongs to the genus Urticina. Male and female (9-10 cm pedal disk diameter, 90 tentacles) spawned 4 years post collection, in early spring (March). Both sexes released gametes through the mouth. The negatively buoyant oocytes (550-600 μm in diameter) quickly settled on the rocks and soft sediments surrounding the female. Lecithotrophic embryonic and larval development occurred on the substratum. Fully developed planula larvae were detected after 17-21 days. Planulae started to crawl and swim around but remained demersal. Metamorphosis and settlement occurred after 30-35 days, exclusively on hard substrata and preferentially on undersurfaces. Offspring grew slowly, developing 8 tentacles after 5 months and 24 tentacles after 12 months (3-4 mm pedal disk diameter). After 2.6 years of growth, the captive-born sea anemones reached 12-16 mm in pedal disk diameter and possessed 48-54 tentacles.

Parametric analysis of occupant ankle and tibia injuries in frontal impact

PubMed Central

Mo, Fuhao; Jiang, Xiaoqing; Duan, Shuyong; Xiao, Zhi; Shi, Wei

2017-01-01

Objective Non-fatal tibia and ankle injuries without proper protection from the restraint system has gotten wide attention from researchers. This study aimed to investigate occupant tibia and ankle injuries under realistic frontal impact environment that is rarely considered in previous experimental and simulant studies. Methods An integrated occupant-vehicle model was established by coupling an isolated car cab model and a hybrid occupant model with a biofidelic pelvis-lower limb model, while its loading conditions were extracted from the realistic full-frontal impact test. A parametric study was implemented concerning instrument panel (IP) design and pedal intrusion/rotation parameters. Results The significant influences of the IP angle, pedal intrusion and pedal rotation on tibia axial force, tibia bending moment and ankle dorsiflexion angle are noted. By coupling their effects, a new evaluation index named CAIEI (Combined Ankle Injury Evaluation Index) is established to evaluate ankle injury (including tibia fractures in ankle region) risk and severity in robustness. Conclusions Overall results and analysis indicate that ankle dorsiflexion angle should be considered when judging the injury in lower limb under frontal impact. Meanwhile, the current index with coupling effects of tibia axial force, bending moment and ankle dorsiflexion angle is in a good correlation with the simulation injury outcomes. PMID:28910377

COMPARISON OF HIGH-DEFINITION OSCILLOMETRIC AND DIRECT ARTERIAL BLOOD PRESSURE MEASUREMENT IN ANESTHETIZED CHEETAHS (ACINONYX JUBATUS).

PubMed

Sant Cassia, Emma V; Boswood, Adrian; Tordiffe, Adrian S W

2015-09-01

Blood pressure measurement reveals important insights into the health of conscious and anesthetized individuals. This is of particular interest in cheetahs (Acinonyx jubatus), which in captivity are known to suffer from chronic diseases that may be associated with hypertension and which often require immobilization for transport or veterinary treatment. Invasive testing methods are considered the gold standard but are not practical in many settings. Consequently, it is important to evaluate the use of noninvasive methods in this species. Measurements for systolic, diastolic, and mean arterial pressure obtained using high-definition oscillometry (HDO) at the coccygeal artery were compared to simultaneous direct measurements obtained via catheterization of the femoral or dorsal pedal artery in eight anesthetized captive cheetahs during nine anesthetic events. Overall, HDO and direct measurements agreed most closely for mean arterial pressure, and the poorest agreement was observed for systolic pressure. There was a tendency for low diastolic pressures to be underestimated and for high diastolic pressures to be overestimated. Across all three parameters, HDO measurements from the tail overestimated directly measured pressures in the femoral artery and underestimated those in the dorsal pedal artery. HDO agreed most closely with directly measured dorsal pedal pressures. Mean arterial pressure showed the greatest precision (standard deviation of 10.2 mm Hg) and lowest bias (-1.2 mm Hg), with 75.9% of readings within 10 mm Hg of the direct dorsal pedal pressure. Agreement with systolic pressure was hindered by a high bias (-10.4 mm Hg), but if a correction factor of +10 mm Hg was applied to all systolic measurements, agreement was improved and 65.7% of readings were within 10 mm Hg of the direct pressure. When compared to criteria defined by the American College of Veterinary Internal Medicine for validation of blood pressure devices, results were favorable, but a limited sample size prevented formal validation.

Muscle function during brief maximal exercise: accurate measurements on a friction-loaded cycle ergometer.

PubMed

Arsac, L M; Belli, A; Lacour, J R

1996-01-01

A friction loaded cycle ergometer was instrumented with a strain gauge and an incremental encoder to obtain accurate measurement of human mechanical work output during the acceleration phase of a cycling sprint. This device was used to characterise muscle function in a group of 15 well-trained male subjects, asked to perform six short maximal sprints on the cycle against a constant friction load. Friction loads were successively set at 0.25, 0.35, 0.45, 0.55, 0.65 and 0.75 N.kg-1 body mass. Since the sprints were performed from a standing start, and since the acceleration was not restricted, the greatest attention was paid to the measurement of the acceleration balancing load due to flywheel inertia. Instantaneous pedalling velocity (v) and power output (P) were calculated each 5 ms and then averaged over each downstroke period so that each pedal downstroke provided a combination of v, force and P. Since an 8-s acceleration phase was composed of about 21 to 34 pedal downstrokes, this many v-P combinations were obtained amounting to 137-180 v-P combinations for all six friction loads in one individual, over the widest functional range of pedalling velocities (17-214 rpm). Thus, the individual's muscle function was characterised by the v-P relationships obtained during the six acceleration phases of the six sprints. An important finding of the present study was a strong linear relationship between individual optimal velocity (vopt) and individual maximal power output (Pmax) (n = 15, r = 0.95, P < 0.001) which has never been observed before. Since vopt has been demonstrated to be related to human fibre type composition both vopt, Pmax and their inter-relationship could represent a major feature in characterising muscle function in maximal unrestricted exercise. It is suggested that the present method is well suited to such analyses.

Impact of angiosome- and nonangiosome-targeted peroneal bypass on limb salvage and healing in patients with chronic limb-threatening ischemia.

PubMed

Ricco, Jean-Baptiste; Gargiulo, Mauro; Stella, Andrea; Abualhin, Mohammad; Gallitto, Enrico; Desvergnes, Mathieu; Belmonte, Romain; Schneider, Fabrice

2017-11-01

Direct (DIR) or indirect (IND) revascularization of pedal angiosomes in patients with chronic limb-threatening ischemia (CLTI) has an unclear impact on limb salvage and healing. The aim of this study was to evaluate the outcomes of DIR and IND revascularization in patients with a peroneal bypass and tissue loss. We conducted a retrospective study of a prospectively maintained database in two European university centers from 2004 to 2015. We extracted from this database all patients with CLTI and tissue loss who had received a bypass to the peroneal artery. All patients underwent angiography before bypass. Revascularization was considered DIR if the wound was in a peroneal angiosome. Wounds, ischemia, and infection were categorized according to the Wound, Ischemia, and foot Infection (WIfI) classification. Limb salvage and amputation-free survival were calculated using the Kaplan-Meier method. Cox regression was used to compare the role of patient characteristics, including diabetes, peroneal runoff, pedal arch angiosome, WIfI grade, chronic kidney disease, and diabetes, in amputation-free-survival. From January 2004 through October 2015, there were 120 peroneal bypasses performed in 120 patients with CLTI and foot tissue loss. Only 55 wounds (46%) could be ascribed to a peroneal angiosome. At 3 years, amputation-free survival in patients with DIR revascularization was 54.9% ± 7.3% compared with 56.5% ± 6.3% in patients with IND revascularization (P = .44), with no significant difference in wound healing. Amputation-free survival at 3 years in patients with two patent peroneal branches was 74.8% ± 6.9% compared with 45.0% ± 6.0% in patients with one patent peroneal branch (P = .003). Amputation-free survival at 3 years in patients with a patent pedal arch (Rutherford 0-1) was 73.0% ± 7.0% vs 45.7% ± 6.0% in patients with incomplete pedal arch (Rutherford 2-3; P = .0002). Amputation-free survival at 3 years in patients with grade 1 or grade 2 WIfI was 87.4% ± 8.3% compared with 48.4% ± 5.3% in patients with grade 3 or grade 4 WIfI (P = .001). Amputation-free survival at 3 years in patients with diabetes was 43.7% ± 6.2% compared with 73.1% ± 6.7% in patients without diabetes (P = .002). Wound healing at 6 months was not significantly improved by its location within or outside a peroneal angiosome. Cox regression analysis demonstrated that diabetes, patency of both peroneal branches, patency of pedal arch, and WIfI stage but not DIR angiosome revascularization were significant predictors of amputation-free survival. Our results suggest that in patients with CLTI and tissue loss receiving a peroneal bypass, patency of both peroneal branches and pedal arch was associated with a better healing rate and a better amputation-free survival rate irrespective of wound angiosome location. Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

EEG potentials predict upcoming emergency brakings during simulated driving

NASA Astrophysics Data System (ADS)

Haufe, Stefan; Treder, Matthias S.; Gugler, Manfred F.; Sagebaum, Max; Curio, Gabriel; Blankertz, Benjamin

2011-10-01

Emergency braking assistance has the potential to prevent a large number of car crashes. State-of-the-art systems operate in two stages. Basic safety measures are adopted once external sensors indicate a potential upcoming crash. If further activity at the brake pedal is detected, the system automatically performs emergency braking. Here, we present the results of a driving simulator study indicating that the driver's intention to perform emergency braking can be detected based on muscle activation and cerebral activity prior to the behavioural response. Identical levels of predictive accuracy were attained using electroencephalography (EEG), which worked more quickly than electromyography (EMG), and using EMG, which worked more quickly than pedal dynamics. A simulated assistance system using EEG and EMG was found to detect emergency brakings 130 ms earlier than a system relying only on pedal responses. At 100 km h-1 driving speed, this amounts to reducing the braking distance by 3.66 m. This result motivates a neuroergonomic approach to driving assistance. Our EEG analysis yielded a characteristic event-related potential signature that comprised components related to the sensory registration of a critical traffic situation, mental evaluation of the sensory percept and motor preparation. While all these components should occur often during normal driving, we conjecture that it is their characteristic spatio-temporal superposition in emergency braking situations that leads to the considerable prediction performance we observed.

EEG potentials predict upcoming emergency brakings during simulated driving.

PubMed

Haufe, Stefan; Treder, Matthias S; Gugler, Manfred F; Sagebaum, Max; Curio, Gabriel; Blankertz, Benjamin

2011-10-01

Emergency braking assistance has the potential to prevent a large number of car crashes. State-of-the-art systems operate in two stages. Basic safety measures are adopted once external sensors indicate a potential upcoming crash. If further activity at the brake pedal is detected, the system automatically performs emergency braking. Here, we present the results of a driving simulator study indicating that the driver's intention to perform emergency braking can be detected based on muscle activation and cerebral activity prior to the behavioural response. Identical levels of predictive accuracy were attained using electroencephalography (EEG), which worked more quickly than electromyography (EMG), and using EMG, which worked more quickly than pedal dynamics. A simulated assistance system using EEG and EMG was found to detect emergency brakings 130 ms earlier than a system relying only on pedal responses. At 100 km h(-1) driving speed, this amounts to reducing the braking distance by 3.66 m. This result motivates a neuroergonomic approach to driving assistance. Our EEG analysis yielded a characteristic event-related potential signature that comprised components related to the sensory registration of a critical traffic situation, mental evaluation of the sensory percept and motor preparation. While all these components should occur often during normal driving, we conjecture that it is their characteristic spatio-temporal superposition in emergency braking situations that leads to the considerable prediction performance we observed.

Persistent inflammation with pedal osteolysis 1 Year after Charcot neuropathic osteoarthropathy

PubMed Central

Sinacore, David R.; Bohnert, Kathryn L.; Smith, Kirk E.; Hastings, Mary K.; Commean, Paul K.; Gutekunst, David J.; Johnson, Jeffrey E.; Prior, Fred W.

2017-01-01

Structured Abstract Aims To determine local and systemic markers of inflammation and bone mineral density (BMD) in the foot and central sites in participants with diabetes mellitus and peripheral neuropathy (DMPN) with and without acute Charcot neuropathic osteoarthropathy (CN). Methods Eighteen participants with DMPN and CN and 19 participants without CN had foot temperature assessments, serum markers of inflammation [C-reactive protein, (CRP) and erythrocyte sedimentation rate, (ESR)] and BMD of the foot, hip and lumbar spine at baseline and 1 year follow-up. Results CN foot temperature difference was higher compared to DMPN controls at baseline (4.2 ± 1.9 °F vs. 1.2 ± 0.9 °F, P < 0.01) and after 1 year (2.9 ± 3.2 °F vs. 0.9 ± 1.1 °F, P < 0.01). Serum inflammatory markers in the CN group were greater at baseline and remained elevated 1 year later compared to DMPN controls (CRP, P =0.02, ESR, P = 0.03). All pedal bones’ BMD decreased an average of 3% in the CN foot with no changes in hip or lumbar spine. DMPN controls’ foot, hip and lumbar spine BMD remained unchanged. Conclusions Local and systemic inflammation persists1 year after CN with an accompanying pedal osteolysis that may contribute to mid foot deformity which is the hallmark of the chronic Charcot foot. PMID:28254346

Presentation and assessment of rideability of a novel single-track vehicle: the Anaconda

NASA Astrophysics Data System (ADS)

Verlinden, O.; Kabeya, P.

2012-08-01

In this paper, a new single-track vehicle, the Anaconda, is presented and modelled according to a multibody theory. This articulated vehicle begins with a traditional bicycle, called the head module, followed by a succession of so-called pedal modules (PMs) equipped with one rear-steered wheel. Each module is connected to the preceding one by a spherical joint. To assess its dynamic behaviour, the model of an Anaconda with two PMs is simulated under the EasyDyn framework, a multibody library based on the minimal coordinates approach. The simulation of such a vehicle cannot be performed without the riders' action, consisting of the torques applied on the handlebars. The latter is implemented through controllers designed by optimal control, from the out-of-plane dynamics of the vehicle going straight ahead at 20 km/h. First, two optimal controllers are determined separately for the Head Module alone on one hand and for the Pedal Module alone on the other hand. They are then implemented on the Anaconda and it appears that the vehicle is close to instability and that the handling of the pedal modules is delicate but humanly possible. Finally, the difficulty in riding the Anaconda is evaluated through the so-called rideability index, which increases, as expected, with the amount of PMs, and shows that good psycho-motor skills will be needed to drive the Anaconda.

VRACK: measuring pedal kinematics during stationary bike cycling.

PubMed

Farjadian, Amir B; Kong, Qingchao; Gade, Venkata K; Deutsch, Judith E; Mavroidis, Constantinos

2013-06-01

Ankle impairment and lower limb asymmetries in strength and coordination are common symptoms for individuals with selected musculoskeletal and neurological impairments. The virtual reality augmented cycling kit (VRACK) was designed as a compact mechatronics system for lower limb and mobility rehabilitation. The system measures interaction forces and cardiac activity during cycling in a virtual environment. The kinematics measurement was added to the system. Due to the constrained problem definition, the combination of inertial measurement unit (IMU) and Kalman filtering was recruited to compute the optimal pedal angular displacement during dynamic cycling exercise. Using a novel benchmarking method the accuracy of IMU-based kinematics measurement was evaluated. Relatively accurate angular measurements were achieved. The enhanced VRACK system can serve as a rehabilitation device to monitor biomechanical and physiological variables during cycling on a stationary bike.

Design and testing of an MRI-compatible cycle ergometer for non-invasive cardiac assessments during exercise

PubMed Central

2012-01-01

Background Magnetic resonance imaging (MRI) is an important tool for cardiac research, and it is frequently used for resting cardiac assessments. However, research into non-pharmacological stress cardiac evaluation is limited. Methods We aimed to design a portable and relatively inexpensive MRI cycle ergometer capable of continuously measuring pedalling workload while patients exercise to maintain target heart rates. Results We constructed and tested an MRI-compatible cycle ergometer for a 1.5 T MRI scanner. Resting and sub-maximal exercise images (at 110 beats per minute) were successfully obtained in 8 healthy adults. Conclusions The MRI-compatible cycle ergometer constructed by our research group enabled cardiac assessments at fixed heart rates, while continuously recording power output by directly measuring pedal force and crank rotation. PMID:22423637

16 CFR 1512.17 - Other requirements.

Code of Federal Regulations, 2011 CFR

2011-01-01

....18(p), and shall exhibit stable handling, turning, and steering characteristics without difficulty of... pedal crank in its lowest position and any training wheels removed, it shall be possible to tilt the...

16 CFR 1512.17 - Other requirements.

Code of Federal Regulations, 2012 CFR

2012-01-01

....18(p), and shall exhibit stable handling, turning, and steering characteristics without difficulty of... pedal crank in its lowest position and any training wheels removed, it shall be possible to tilt the...

16 CFR 1512.17 - Other requirements.

Code of Federal Regulations, 2014 CFR

2014-01-01

....18(p), and shall exhibit stable handling, turning, and steering characteristics without difficulty of... pedal crank in its lowest position and any training wheels removed, it shall be possible to tilt the...

Leg joint power output during progressive resistance FES-LCE cycling in SCI subjects: developing an index of fatigue.

PubMed

Haapala, Stephenie A; Faghri, Pouran D; Adams, Douglas J

2008-04-26

The purpose of this study was to investigate the biomechanics of the hip, knee and ankle during a progressive resistance cycling protocol in an effort to detect and measure the presence of muscle fatigue. It was hypothesized that knee power output can be used as an indicator of fatigue in order to assess the cycling performance of SCI subjects. Six spinal cord injured subjects (2 incomplete, 4 complete) between the ages of twenty and fifty years old and possessing either a complete or incomplete spinal cord injury at or below the fourth cervical vertebra participated in this study. Kinematic data and pedal forces were recorded during cycling at increasing levels of resistance. Ankle, knee and hip power outputs and resultant pedal force were calculated. Ergometer cadence and muscle stimulation intensity were also recorded. The main findings of this study were: (a) ankle and knee power outputs decreased, whereas hip power output increased with increasing resistance, (b) cadence, stimulation intensity and resultant pedal force in that combined order were significant predictors of knee power output and (c) knowing the value of these combined predictors at 10 rpm, an index of fatigue can be developed, quantitatively expressing the power capacity of the knee joint with respect to a baseline power level defined as fatigue. An index of fatigue was successfully developed, proportionalizing knee power capacity during cycling to a predetermined value of fatigue. The fatigue index value at 0/8th kp, measured 90 seconds into active, unassisted pedaling was 1.6. This indicates initial power capacity at the knee to be 1.6 times greater than fatigue. The fatigue index decreased to 1.1 at 2/8th kp, representing approximately a 30% decrease in the knee's power capacity within a 4 minute timespan. These findings suggest that the present cycling protocol is not sufficient for a rider to gain the benefits of FES and thus raises speculation as to whether or not progressive resistance cycling is an appropriate protocol for SCI subjects.

Leg joint power output during progressive resistance FES-LCE cycling in SCI subjects: developing an index of fatigue

PubMed Central

Haapala, Stephenie A; Faghri, Pouran D; Adams, Douglas J

2008-01-01

Background The purpose of this study was to investigate the biomechanics of the hip, knee and ankle during a progressive resistance cycling protocol in an effort to detect and measure the presence of muscle fatigue. It was hypothesized that knee power output can be used as an indicator of fatigue in order to assess the cycling performance of SCI subjects. Methods Six spinal cord injured subjects (2 incomplete, 4 complete) between the ages of twenty and fifty years old and possessing either a complete or incomplete spinal cord injury at or below the fourth cervical vertebra participated in this study. Kinematic data and pedal forces were recorded during cycling at increasing levels of resistance. Ankle, knee and hip power outputs and resultant pedal force were calculated. Ergometer cadence and muscle stimulation intensity were also recorded. Results The main findings of this study were: (a) ankle and knee power outputs decreased, whereas hip power output increased with increasing resistance, (b) cadence, stimulation intensity and resultant pedal force in that combined order were significant predictors of knee power output and (c) knowing the value of these combined predictors at 10 rpm, an index of fatigue can be developed, quantitatively expressing the power capacity of the knee joint with respect to a baseline power level defined as fatigue. Conclusion An index of fatigue was successfully developed, proportionalizing knee power capacity during cycling to a predetermined value of fatigue. The fatigue index value at 0/8th kp, measured 90 seconds into active, unassisted pedaling was 1.6. This indicates initial power capacity at the knee to be 1.6 times greater than fatigue. The fatigue index decreased to 1.1 at 2/8th kp, representing approximately a 30% decrease in the knee's power capacity within a 4 minute timespan. These findings suggest that the present cycling protocol is not sufficient for a rider to gain the benefits of FES and thus raises speculation as to whether or not progressive resistance cycling is an appropriate protocol for SCI subjects. PMID:18439300

16 CFR § 1512.17 - Other requirements.

Code of Federal Regulations, 2013 CFR

2013-01-01

..., § 1512.18(p), and shall exhibit stable handling, turning, and steering characteristics without difficulty... the pedal crank in its lowest position and any training wheels removed, it shall be possible to tilt...

Older-driver foot movements.

DOT National Transportation Integrated Search

2017-07-01

This study explored how drivers 60 and older control the accelerator and brake while driving and parking. It built upon : the findings of a study documenting the prevalence and characteristics associated with pedal misapplication crashes : (Lococo, S...

78 FR 27315 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-10

.... Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New... pedal was loose. Another operator reported a fractured bolt during the airplane pushback. When the...

Yo-yo Pull Demonstration

NASA Astrophysics Data System (ADS)

Layton, William

2013-03-01

A popular demonstration involves placing a yo-yo on a level table and gently pulling the string horizontally when it is wrapped to come out below the center of the yo-yo's axis. Students are then asked to predict which way the yo-yo will move. A similar demonstration is performed with a tricycle by pulling forward on a pedal with the pedal down in its lowest position.2,3 As well as pulling the yo-yo horizontally, often the string is lifted until the angle it makes with the table causes no motion. This occurs when the line extended from the string intersects the point of contact of the yo-yo with the table.4 This paper describes an apparatus that extends these demonstrations to the situation where the force pulling the yo-yo is still horizontal yet is below the level of the table.

The phenomenology of deep hypnosis: quiescent and physically active.

PubMed

Cardeña, Etzel

2005-01-01

To study the phenomenology of hypnotic virtuosos, the author employed a 2 (hypnosis vs. control) x 3 (quiescent, pedaling a stationary bike, having a motor pedal the bike) within-subjects design with quantitative and qualitative measures. In a "neutral hypnosis" context with the only suggestion being to go as deeply into hypnosis as possible, participants reported alterations in body image, time sense, perception and meaning, sense of being in an altered state of awareness, affect, attention, and imagery. They also mentioned less self-awareness, rationality, voluntary control, and memory. Analyses of the 3 physical conditions showed that hypnotic experiences were overall similar, although quiescence was more conducive to alterations of body image and reports of depth. These results suggest that hypnotic virtuosos have alterations of consciousness that can be better conceptualized as distinct states rather than being on a continuum.

Contrary effects of octopamine receptor ligands on behavioral and neuronal changes in locomotion of lymnaea.

PubMed

Miyamae, Yurie; Komuro, Mami; Murata, Aya; Aono, Kanako; Nishikata, Kaori; Kanazawa, Akira; Fujito, Yutaka; Komatsu, Takumi; Ito, Daisuke; Abe, Takashi; Nagayama, Masafumi; Uchida, Tsutomu; Gohara, Kazutoshi; Murakami, Jun; Kawai, Ryo; Hatakeyama, Dai; Lukowiak, Ken; Ito, Etsuro

2010-02-01

The pond snail Lymnaea stagnalis moves along the sides and bottom of an aquarium, but it can also glide upside down on its back below the water's surface. We have termed these two forms of locomotion "standard locomotion" and "upside-down gliding," respectively. Previous studies showed that standard locomotion is produced by both cilia activity on the foot and peristaltic contraction of the foot muscles, whereas upside-down gliding is mainly caused by cilia activity. The pedal A neurons are thought to receive excitatory octopaminergic input, which ultimately results in increased cilia beating. However, the relationship between locomotory speed and the responses of these neurons to octopamine is not known. We thus examined the effects of both an agonist and an antagonist of octopamine receptors on locomotory speed and the firing rate of the pedal A neurons. We also examined, at the electron and light-microscopic levels, whether structural changes occur in cilia following the application of either an agonist or an antagonist of octopamine receptors to the central nervous system (CNS). We found that the application of an octopamine antagonist to the CNS increased the speed of both forms of locomotion, whereas application of octopamine increased only the firing rate of the pedal A neurons. Microscopic examination of the cilia proved that there were no changes in their morphology after application of octopamine ligands. These data suggest that there is an unidentified octopaminergic neuronal network in the CNS whose activation reduces cilia movement and thus locomotory speed.

The foot of Homo naledi.

PubMed

Harcourt-Smith, W E H; Throckmorton, Z; Congdon, K A; Zipfel, B; Deane, A S; Drapeau, M S M; Churchill, S E; Berger, L R; DeSilva, J M

2015-10-06

Modern humans are characterized by a highly specialized foot that reflects our obligate bipedalism. Our understanding of hominin foot evolution is, although, hindered by a paucity of well-associated remains. Here we describe the foot of Homo naledi from Dinaledi Chamber, South Africa, using 107 pedal elements, including one nearly-complete adult foot. The H. naledi foot is predominantly modern human-like in morphology and inferred function, with an adducted hallux, an elongated tarsus, and derived ankle and calcaneocuboid joints. In combination, these features indicate a foot well adapted for striding bipedalism. However, the H. naledi foot differs from modern humans in having more curved proximal pedal phalanges, and features suggestive of a reduced medial longitudinal arch. Within the context of primitive features found elsewhere in the skeleton, these findings suggest a unique locomotor repertoire for H. naledi, thus providing further evidence of locomotor diversity within both the hominin clade and the genus Homo.

Percutaneous Femoropopliteal Recanalization Using a Completely Transpedal/Transtibial Approach

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

Clark, Timothy W.I., E-mail: timothy.clark@uphs.upenn.edu; Watts, Micah M.; Kwan, Tak W.

PurposeTo report preliminary experience with femoropopliteal revascularization using a completely transpedal/transtibial approach.Materials and MethodsThree patients with Rutherford 3–4 disease underwent revascularization of TASC C/D lesions using a pedal/tibial artery as the only site of arterial access.ResultsOne patient with a chronic superficial femoral artery occlusion had continuity achieved to the common femoral artery using a dedicated reentry device and stenting; in a second patient, an occluded popliteal artery stent was successfully revised with an endograft; and in a third patient with morbid obesity, a chronic SFA occlusion was successfully stented. All patients experienced complete resolution of presenting symptoms; no puncture sitemore » complications were seen.ConclusionsUse of a pedal/tibial approach as the sole site of arterial access may become an important access technique for femoropopliteal revascularization when patients have limited femoral access options.« less

The foot of Homo naledi

PubMed Central

Harcourt-Smith, W. E. H.; Throckmorton, Z.; Congdon, K. A.; Zipfel, B.; Deane, A. S.; Drapeau, M. S. M.; Churchill, S. E.; Berger, L. R.; DeSilva, J. M.

2015-01-01

Modern humans are characterized by a highly specialized foot that reflects our obligate bipedalism. Our understanding of hominin foot evolution is, although, hindered by a paucity of well-associated remains. Here we describe the foot of Homo naledi from Dinaledi Chamber, South Africa, using 107 pedal elements, including one nearly-complete adult foot. The H. naledi foot is predominantly modern human-like in morphology and inferred function, with an adducted hallux, an elongated tarsus, and derived ankle and calcaneocuboid joints. In combination, these features indicate a foot well adapted for striding bipedalism. However, the H. naledi foot differs from modern humans in having more curved proximal pedal phalanges, and features suggestive of a reduced medial longitudinal arch. Within the context of primitive features found elsewhere in the skeleton, these findings suggest a unique locomotor repertoire for H. naledi, thus providing further evidence of locomotor diversity within both the hominin clade and the genus Homo. PMID:26439101

The effects of control-display gain on performance of race car drivers in an isometric braking task.

PubMed

de Winter, J C F; de Groot, S

2012-12-01

To minimise lap times during car racing, it is important to build up brake forces rapidly and maintain precise control. We examined the effect of the amplification factor (gain) between brake pedal force and a visually represented output value on a driver's ability to track a target value. The test setup was a formula racing car cockpit fitted with an isometric brake pedal. Thirteen racing drivers performed tracking tasks with four control-display gains and two target functions: a step function (35 trials per gain) and a multisine function (15 trials per gain). The control-display gain had only minor effects on root mean-squared error between output value and target value, but it had large effects on build-up speed, overshoot, within-participants variability, and self-reported physical load. The results confirm the hypothesis that choosing an optimum gain involves balancing stability against physical effort.

Selective training-induced thigh muscles hypertrophy in professional road cyclists.

PubMed

Hug, François; Marqueste, Tanguy; Le Fur, Yann; Cozzone, Patrick J; Grélot, Laurent; Bendahan, David

2006-07-01

Muscular adaptations linked to a high volume and intensity of training have been scarcely reported. We aimed at documenting, using MRI, the cross-sectional area changes associated with a high volume and intensity of training in 11 thigh muscles of a population of professional road cyclists as compared with sport science students. We were also interested in determining, whether selective muscle hypertrophy in professional road cyclists, if any, was correlated to selective exercise-induced T (2) changes during a pedaling exercise on a cycloergometer. Cross-sectional area of 11 thigh muscles was quantified in sixteen subjects (i.e. eight professional road cyclists and eight sport science students) using MRI. In addition, transverse relaxation times (T (2)) were measured before and just after a maximal standardized constant-load exercise in order to investigate exercise-related T (2) changes in these muscles. Professional road cyclists had a significantly higher relative amount of muscle (including the whole set of thigh muscles, 90.5+/-3.3%) as compared to controls (81.6+/-7.3%). Regarding relative values expressed with respect to the total thigh muscles CSA, Vastus lateralis and Biceps femoris CSA were significantly larger in cyclists whereas CSA of the Vastus intermedius was smaller. However, this selective hypertrophy was not correlated to the exercise-induced T (2)-increase. We have reported, for the first time, a selective hypertrophy of Vastus lateralis and Biceps femoris in professional road cyclists confirming their involvement in pedaling task and suggesting a possible cause-effect relationship between muscle activation and hypertrophy, associated with a specific pedaling skill.

Effects of shoe cleat position on physiology and performance of competitive cyclists.

PubMed

Paton, Carl D

2009-12-01

Aerobic economy is an important factor that affects the performance of competitive cyclists. It has been suggested that placing the foot more anteriorly on the bicycle pedals may improve economy over the traditional foot position by improving pedaling efficiency. The current study examines the effects of changing the anterior-posterior pedal foot position on the physiology and performance of well-trained cyclists. In a crossover study, 10 competitive cyclists completed two maximal incremental and two submaximal tests in either their preferred (control) or a forward (arch) foot position. Maximum oxygen consumption and peak power output were determined from the incremental tests for both foot positions. On two further occasions, cyclists also completed a two-part 60-min submaximal test that required them to maintain a constant power output (equivalent to 60% of their incremental peak power) for 30 min, during which respiratory and blood lactate samples were taken at predetermined intervals. Thereafter, subjects completed a 30-min self-paced maximal effort time trial. Relative to the control, the mean changes (+/-90% confidence limits) in the arch condition were as follows: maximum oxygen consumption, -0.5% (+/-2.0%); incremental peak power output, -0.8% (+/-1.3%); steady-state oxygen consumption at 60%, -2.4% (+/-1.1%); steady-state heart rate 60%, 0.4% (+/-1.7%); lactate concentration 60%, 8.7% (+/-14.4%); and mean time trial power, -1.5% (+/-2.9%). We conclude that there was no substantial physiological or performance advantage in this group using an arch-cleat shoe position in comparison with a cyclist's normal preferred condition.

An experimental investigation of chemical communication in the polar bear

USGS Publications Warehouse

Owen, Megan A.; Swaisgood, Ronald R.; Slocomb, C.; Amstrup, Steven C.; Durner, George M.; Simac, Kristin S.; Pessier, Allan P.

2015-01-01

The polar bear (Ursus maritimus), with its wide-ranging movements, solitary existence and seasonal reproduction, is expected to favor chemosignaling over other communication modalities. However, the topography of its Arctic sea ice habitat is generally lacking in stationary vertical substrates routinely used for targeted scent marking in other bears. These environmental constraints may have shaped a marking strategy, unique to polar bears, for widely dispersed continuous dissemination of scent via foot pads. To investigate the role of chemical communication, pedal scents were collected from free-ranging polar bears of different sex and reproductive classes captured on spring sea ice in the Beaufort and Chukchi seas, and presented in a controlled fashion to 26 bears in zoos. Results from behavioral bioassays indicated that bears, especially females, were more likely to approach conspecific scent during the spring than the fall. Male flehmen behavior, indicative of chemosignal delivery to the vomeronasal organ, differentiated scent donor by sex and reproductive condition. Histologic examination of pedal skin collected from two females indicated prominent and profuse apocrine glands in association with large compound hair follicles, suggesting that they may produce scents that function as chemosignals. These results suggest that pedal scent, regardless of origin, conveys information to conspecifics that may facilitate social and reproductive behavior, and that chemical communication in this species has been adaptively shaped by environmental constraints of its habitat. However, continuously distributed scent signals necessary for breeding behavior may prove less effective if current and future environmental conditions cause disruption of scent trails due to increased fracturing of sea ice.

Secondary mediation and regression analyses of the PTClinResNet database: determining causal relationships among the International Classification of Functioning, Disability and Health levels for four physical therapy intervention trials.

PubMed

Mulroy, Sara J; Winstein, Carolee J; Kulig, Kornelia; Beneck, George J; Fowler, Eileen G; DeMuth, Sharon K; Sullivan, Katherine J; Brown, David A; Lane, Christianne J

2011-12-01

Each of the 4 randomized clinical trials (RCTs) hosted by the Physical Therapy Clinical Research Network (PTClinResNet) targeted a different disability group (low back disorder in the Muscle-Specific Strength Training Effectiveness After Lumbar Microdiskectomy [MUSSEL] trial, chronic spinal cord injury in the Strengthening and Optimal Movements for Painful Shoulders in Chronic Spinal Cord Injury [STOMPS] trial, adult stroke in the Strength Training Effectiveness Post-Stroke [STEPS] trial, and pediatric cerebral palsy in the Pediatric Endurance and Limb Strengthening [PEDALS] trial for children with spastic diplegic cerebral palsy) and tested the effectiveness of a muscle-specific or functional activity-based intervention on primary outcomes that captured pain (STOMPS, MUSSEL) or locomotor function (STEPS, PEDALS). The focus of these secondary analyses was to determine causal relationships among outcomes across levels of the International Classification of Functioning, Disability and Health (ICF) framework for the 4 RCTs. With the database from PTClinResNet, we used 2 separate secondary statistical approaches-mediation analysis for the MUSSEL and STOMPS trials and regression analysis for the STEPS and PEDALS trials-to test relationships among muscle performance, primary outcomes (pain related and locomotor related), activity and participation measures, and overall quality of life. Predictive models were stronger for the 2 studies with pain-related primary outcomes. Change in muscle performance mediated or predicted reductions in pain for the MUSSEL and STOMPS trials and, to some extent, walking speed for the STEPS trial. Changes in primary outcome variables were significantly related to changes in activity and participation variables for all 4 trials. Improvement in activity and participation outcomes mediated or predicted increases in overall quality of life for the 3 trials with adult populations. Variables included in the statistical models were limited to those measured in the 4 RCTs. It is possible that other variables also mediated or predicted the changes in outcomes. The relatively small sample size in the PEDALS trial limited statistical power for those analyses. Evaluating the mediators or predictors of change between each ICF level and for 2 fundamentally different outcome variables (pain versus walking) provided insights into the complexities inherent across 4 prevalent disability groups.

Predictors of Post-operative Mycetoma Recurrence Using Machine-Learning Algorithms: The Mycetoma Research Center Experience.

PubMed

Wadal, Ali; Elhassan, Tusneem Ahmed; Zein, Hajer Ahmed; Abdel-Rahman, Manar Elsheikh; Fahal, Ahmed Hassan

2016-10-01

Post-operative recurrence in mycetoma after adequate medical and surgical treatment is common and a serious problem. It has health, socio-economic and psychological detrimental effects on patients and families. It is with this in mind, we set out to determine the predictors of post-operative recurrence in mycetoma. The study included 1013 patients with Madurella mycetomatis causing eumycetoma who underwent surgical excision at the Mycetoma Research Centre, Khartoum, Sudan in the period 1991-2015. The clinical records of these patients were reviewed and relevant information was collected using a pre-designed data collection sheet. The study showed, 276 patients (27.2%) of the studied population developed post-operative recurrence, 217 were males (78.6%) and 59 were females (21.4%). Their age ranged between 5 to 70 years with a mean of 32 years. The disease duration at presentation ranged between 2 months and 17 years. The majority of the patients 118 (42.8%) had mycetoma of 1 year duration. In this study, students were the most affected; 105 (38%) followed by workers 70 (25.4%), then farmers 48(17.3%). The majority of the patients were from the Central Sudan 207 (75%), Western Sudan 53 (19.2%) while 11 patients (4%) were from the Northern part. Past history of surgical intervention performed elsewhere was reported in 196 patients (71.1%). Family history of mycetoma was reported in 50 patients (18.1%). The foot was the most affected site, 245 (88.7%), followed by the hand seen in 19 (6.8%) patients and 44 (4.5%) had different sites involvement. Most of the patients 258 (93.5%) had wide local surgical excisions while 18 had major amputation. The model predicted that the certain groups have a high risk of recurrence, and these include patients with disease duration greater than 10 years and extra-pedal mycetoma. Patients with disease duration between [5-10] years, with pedal mycetoma, who had previous surgery, with positive family history and underwent wide local surgical excision. Patients with disease duration [5-10] years, with pedal mycetoma, had previous surgery, with no family history but presented with a disease size (> 10 cm), were non- farmers and underwent wide local surgical excision. Other groups are patients with disease duration (≤5 years), with pedal mycetoma, age <59 years, living in the Western /Eastern / Southern regions of the Sudan and with positive family history and had wide local surgical excision. Also included patients with disease duration (≤5 years), with pedal mycetoma, aged <59 years, living in the northern or central region, with no family history but presented with a disease size >10 cm, working as farmers or students and underwent wide local surgical excision. In conclusion, these groups of patients need special care to reduce the incidence of post-operative recurrence with its morbidity and detrimental consequences. In depth studies for the other predisposing factors for post-operative recurrence such as genetic, immunological and environmental factors are needed.

An illustrated analysis of North Carolina traffic crash statistics for 2006

DOT National Transportation Integrated Search

2006-01-01

This books purpose is to serve as a resource for traffic safety experts, : public officials and those interested in making North Carolinas roadways, : sidewalks and pedal-cyclist paths safe for all of us who travel on them. It : presents detail...

Pedal angiography in peripheral arterial occlusive disease: first-pass i.v. contrast-enhanced MR angiography with blood pool contrast medium versus intraarterial digital subtraction angiography.

PubMed

Kos, Sebastian; Reisinger, Clemens; Aschwanden, Markus; Bongartz, Georg M; Jacob, Augustinus L; Bilecen, Deniz

2009-03-01

The purpose of this study was to prospectively evaluate first-pass i.v. gadofosveset-enhanced MR angiography in patients with peripheral arterial occlusive disease for visualization of the pedal arteries and stenosis or occlusion of those arteries with intraarterial digital subtraction angiography as the reference standard. Twenty patients with peripheral arterial occlusive disease (nine women, 11 men; age-range 58-83 years) were prospectively enrolled. Gadofosveset first-pass contrast-enhanced MR angiography was performed with a 1.5-T system, a dedicated foot coil, and cuff compression to the calf. Arterial segments were assessed for degree of arterial stenosis, arterial visibility, diagnostic utility, and venous contamination. Detection of vessel stenosis or occlusion was evaluated in comparison with findings at digital subtraction angiography. The unpaired Student's t test was used to test arterial visibility with the two techniques. First-pass MR angiography with gadofosveset had good diagnostic utility in 83.9% of all segments and no venous contamination in 96.8% of all segments. There was no difference between the performance of intraarterial digital subtraction angiography and that of i.v. contrast-enhanced MR angiography in arterial visibility overall (p = 0.245) or in subgroup analysis of surgical arterial bypass targets (p = 0.202). The overall sensitivity, specificity, and accuracy of i.v. gadofosveset-enhanced MR angiography for characterization of clinically significant stenosis and occlusion were 91.4%, 96.1%, and 93.9%. In the subgroup analysis, the sensitivity, specificity, and accuracy were 85.5%, 96.5%, and 92.1%. Gadofosveset-enhanced MR angiography of the pedal arteries in patients with peripheral arterial occlusive disease has arterial visibility equal to that of digital subtraction angiography and facilitates depiction of clinically significant stenosis and occlusion.

Road safety: serious injuries remain a major unsolved problem.

PubMed

Beck, Ben; Cameron, Peter A; Fitzgerald, Mark C; Judson, Rodney T; Teague, Warwick; Lyons, Ronan A; Gabbe, Belinda J

2017-09-18

To investigate temporal trends in the incidence, mortality, disability-adjusted life-years (DALYs), and costs of health loss caused by serious road traffic injury. A retrospective review of data from the population-based Victorian State Trauma Registry and the National Coronial Information System on road traffic-related deaths (pre- and in-hospital) and major trauma (Injury Severity Score > 12) during 2007-2015.Main outcomes and measures: Temporal trends in the incidence of road traffic-related major trauma, mortality, DALYs, and costs of health loss, by road user type. There were 8066 hospitalised road traffic major trauma cases and 2588 road traffic fatalities in Victoria over the 9-year study period. There was no change in the incidence of hospitalised major trauma for motor vehicle occupants (incidence rate ratio [IRR] per year, 1.00; 95% CI, 0.99-1.01; P = 0.70), motorcyclists (IRR, 0.99; 95% CI, 0.97-1.01; P = 0.45) or pedestrians (IRR, 1.00; 95% CI, 0.97-1.02; P = 0.73), but the incidence for pedal cyclists increased 8% per year (IRR, 1.08; 95% CI; 1.05-1.10; P < 0.001). While DALYs declined for motor vehicle occupants (by 13% between 2007 and 2015), motorcyclists (32%), and pedestrians (5%), there was a 56% increase in DALYs for pedal cyclists. The estimated costs of health loss associated with road traffic injuries exceeded $14 billion during 2007-2015, although the cost per patient declined for all road user groups. As serious injury rates have not declined, current road safety targets will be difficult to meet. Greater attention to preventing serious injury is needed, as is further investment in road safety, particularly for pedal cyclists.

Detomidine-diazepam-ketamine anaesthesia in buffalo (Bubalus bubalis) calves.

PubMed

Pawde, A M; Amarpal; Kinjavdekar, P; Aithal, H P; Pratap, K; Bisht, G S

2000-04-01

Eight buffalo calves (8-12 months, 70-100 kg) were randomly assigned to two groups of four animals each. Animals of group I were given detomidine (100 micrograms/kg), whereas animals of group II received a mixture of detomidine (100 micrograms/kg), diazepam (100 micrograms/kg) and ketamine (3 mg/kg) (DDK) intravenously. Various clinical parameters, such as weak time, down time, pedal and pinprick reflexes, muscle relaxation and extent of sedation, as well as heart and respiratory rates and electrocardiograms were measured before (time 0) and 15, 30, 45, 60, 75 and 90 min after treatment. In all the animals of group II (DDK), the pedal reflex was completely abolished (score: 3.00 +/- 0.00) within 5 min, the pinprick response was either very weak or it was completely abolished at this interval. Muscle relaxation and sedation were excellent within 5 min of DDK administration. The depth of sedation and analgesia was maximum from 5 to 15 min postinjection. Detomidine alone, however, failed to produce appropriate depression of the pedal and pinprick reflexes, sedation was mild and muscle relaxation was inadequate. Heart rate showed a significant (P < 0.05) decrease in group I, but the decrease was non-significant in group II. A more pronounced increase in respiratory rate was observed in group I as compared to group II. Animals of both groups recovered within 90 min without any complication. Minimal changes in the cardiovascular system in the group given the DDK combination were an advantage over the group given detomidine. The results indicated that DDK combination is safe and suitable for 15 min of anaesthesia with excellent muscle relaxation and has only limited cardiorespiratory effects in buffaloes.

Designing local solutions for emptying pit latrines in low-income urban settlements (Malawi)

NASA Astrophysics Data System (ADS)

Chipeta, W. C.; Holm, R. H.; Kamanula, J. F.; Mtonga, W. E.; de los Reyes, F. L.

2017-08-01

A lack of effective options in local technology poses challenges when onsite household sanitation facilities are eventually filled to capacity in unplanned settlement areas within Mzuzu City, located in northern Malawi. Vacuum trucks currently dominate the market but focus on emptying septic tanks in the more easily accessible planned settlement areas, rather than servicing the pit latrines common in unplanned settlement areas. As a result, households in the unplanned settlement areas within Mzuzu rely primarily on manual pit emptying (i.e., shoveling by hand) or digging a new pit latrine. These practices have associated health risks and are limited by space constraints. This research focused on filling the technological gap through the design, development, and testing of a pedal powered modified Gulper pump using locally available materials and fabrication. A modified pedal powered Gulper technology was developed and demonstrated to be capable of lifting fecal sludge from a depth of 1.5 m with a mean flow rate of 0.00058 m3/s. If the trash content was low, a typical pit latrine with a volume of 1-4 m3 could be emptied within 1-2 h. Based on the findings in our research Phase IV, the pedal powered Gulper modification is promising as a potential emptying technology for lined pit latrines in unplanned settlement areas. The success rate of the technology is about 17% (5 out 30 sampled lined pit latrines were successful) and reflects the difficulty in finding a single technology that can work well in all types of pit latrines with varying contents. We note that cost should not be the only design criteria and acknowledge the challenge of handling trash in pit latrines.

A metabolic basis for impaired muscle force production and neuromuscular compensation during sprint cycling.

PubMed

Bundle, Matthew W; Ernst, Carrie L; Bellizzi, Matthew J; Wright, Seth; Weyand, Peter G

2006-11-01

For both different individuals and modes of locomotion, the external forces determining all-out sprinting performances fall predictably with effort duration from the burst maximums attained for 3 s to those that can be supported aerobically as trial durations extend to roughly 300 s. The common time course of this relationship suggests a metabolic basis for the decrements in the force applied to the environment. However, the mechanical and neuromuscular responses to impaired force production (i.e., muscle fatigue) are generally considered in relation to fractions of the maximum force available, or the maximum voluntary contraction (MVC). We hypothesized that these duration-dependent decrements in external force application result from a reliance on anaerobic metabolism for force production rather than the absolute force produced. We tested this idea by examining neuromuscular activity during two modes of sprint cycling with similar external force requirements but differing aerobic and anaerobic contributions to force production: one- and two-legged cycling. In agreement with previous studies, we found greater peak per leg aerobic metabolic rates [59% (+/-6 SD)] and pedal forces at VO2 peak [30% (+/-9)] during one- vs. two-legged cycling. We also determined downstroke pedal forces and neuromuscular activity by surface electromyography during 15 to 19 all-out constant load sprints lasting from 12 to 400 s for both modes of cycling. In support of our hypothesis, we found that the greater reliance on anaerobic metabolism for force production induced compensatory muscle recruitment at lower pedal forces during two- vs. one-legged sprint cycling. We conclude that impaired muscle force production and compensatory neuromuscular activity during sprinting are triggered by a reliance on anaerobic metabolism for force production.

Can vehicle longitudinal jerk be used to identify aggressive drivers? An examination using naturalistic driving data.

PubMed

Feng, Fred; Bao, Shan; Sayer, James R; Flannagan, Carol; Manser, Michael; Wunderlich, Robert

2017-07-01

This paper investigated the characteristics of vehicle longitudinal jerk (change rate of acceleration with respect to time) by using vehicle sensor data from an existing naturalistic driving study. The main objective was to examine whether vehicle jerk contains useful information that could be potentially used to identify aggressive drivers. Initial investigation showed that there are unique characteristics of vehicle jerk in drivers' gas and brake pedal operations. Thus two jerk-based metrics were examined: (1) driver's frequency of using large positive jerk when pressing the gas pedal, and (2) driver's frequency of using large negative jerk when pressing the brake pedal. To validate the performance of the two metrics, drivers were firstly divided into an aggressive group and a normal group using three classification methods (1) traveling at excessive speed (speeding), (2) following too closely to a front vehicle (tailgating), and (3) their association with crashes or near-crashes in the dataset. The results show that those aggressive drivers defined using any of the three methods above were associated with significantly higher values of the two jerk-based metrics. Between the two metrics the frequency of using large negative jerk seems to have better performance in identifying aggressive drivers. A sensitivity analysis shows the findings were largely consistent with varying parameters in the analysis. The potential applications of this work include developing quantitative surrogate safety measures to identify aggressive drivers and aggressive driving, which could be potentially used to, for example, provide real-time or post-ride performance feedback to the drivers, or warn the surrounding drivers or vehicles using the connected vehicle technologies. Copyright © 2017 Elsevier Ltd. All rights reserved.

A priming effect of benthic gastropod mucus on sedimentary organic matter remineralization

NASA Astrophysics Data System (ADS)

Hannides, A. K.; Aller, R. C.

2016-02-01

Mucous gels are produced by benthic animals rapidly and in copious amounts, and have previously been shown to significantly affect diffusion rates of redox-sensitive ions and organic compounds in sediment pore waters. They are also a highly likely priming substrate whose addition in modest amounts affects sedimentary organic matter remineralization. We tested the priming effect of benthic infaunal mucus using secretions of the common gastropod Neverita duplicata as model substrate. Their composition is typical of marine molluscan mucus, consisting primarily of water (>96% by weight), which is in relative equilibrium with seawater. Salt-free dry weight constitutes 0.7% and 0.6% of total pedal and hypobranchial mucus, respectively. The C:N ratios of pedal and hypobranchial mucus indicate that the organic component consists of a mucopolysaccharide-glycoprotein complex that varies depending on its function, while low C:S ratios of the insoluble component and positive staining with Alcian Blue dye are indicative of S-ester and alkyl-SO42- groups bridging mucopolysaccharide and glycoprotein components. Anoxic incubations of pedal mucus of N. duplicata, sediment, and mucus-sediment mixture, resulted in the anaerobic generation of ΣCO2 and NH4+ at ratios lower than initial C:N ratios, indicating the preferential decomposition of N-rich moieties. Production rates of SCO2 and NH4+ in mucus-sediment incubations are higher, by 9±16% and 29±11%, respectively, than those predicted from linear addition of mucus-only and sediment-only rates. The statistically significant accelerated remineralization rate of N in the presence of modest mucus contribution (0.2% of total N), suggests that benthic mucus addition affects sedimentary organic matter remineralization processes through a "priming" effect.

Non-enhanced, ECG-gated MR angiography of the pedal vasculature: comparison with contrast-enhanced MR angiography and digital subtraction angiography in peripheral arterial occlusive disease.

PubMed

Schubert, Tilman; Takes, Martin; Aschwanden, Markus; Klarhoefer, Markus; Haas, Tanja; Jacob, Augustinus L; Liu, David; Gutzeit, Andreas; Kos, Sebastian

2016-08-01

This study was conducted in order to compare a high resolution, non-contrast-enhanced MRA (NATIVE SPACE, NE-MRA) of the pedal vasculature with contrast-enhanced MRA (CE-MRA) and digital subtraction angiography (DSA) in patients with peripheral arterial occlusive disease (PAOD). The prospective study consists of 20 PAOD patients. All patients underwent percutaneous transluminal angioplasty or stenting and received MR angiographies the following day. With CE-MRA, 75.7 % of vessel segments showed good, 16.4 % suboptimal and 7.9 % not usable image quality. With NE-MRA, 64.6 % showed good, 18.6 % suboptimal and 16.8 % not usable image quality. CE-MRA showed a sensitivity and negative predictive value of 90 %/95 % regarding significant stenosis (greater than 50 %), and specificity and positive predictive value were 88 %/77 %. Accordingly, sensitivity and negative predictive value for the NE-MRA were 96 %/97 % and specificity and positive predictive value were 80 %/69 % for stenoses greater than 50 %. The applied NE-MRA technique achieves high diagnostic accuracy even in very small distal arteries of the foot. However, the rate of non-diagnostic vessel segments is considerably higher for NE-MRA than for CE-MRA. NE-MRA is a valuable alternative to CE-MRA in selected patients. • Comparison of non-enhanced MRA with contrast-enhanced MRA and DSA as gold standard. • High resolution MRA at 3 T for the depiction of small pedal vessels. • Evaluation of high resolution non-enhanced MRA in PAOD patients.

Using haptic feedback to increase seat belt use of service vehicle drivers.

DOT National Transportation Integrated Search

2011-01-01

This study pilot-tested a new application of a technology-based intervention to increase seat belt use. The technology was based on a : contingency in which unbelted drivers experienced sustained haptic feedback to the gas pedal when they exceeded 25...

Alcohol-induced physiological displacements and their effects on flight-related functions.

DOT National Transportation Integrated Search

1982-03-01

Tolerances of human subjects for orthostasis and physical work were determined at a simulated altitude of 3,048 m. Orthostasis was induced with a lower body negative pressure (LBNP) device and physical work was done on a pedal ergometer. Altitude was...

Measuring the ability of military aircrews to adapt to perceived stressors when undergoing centrifuge training.

PubMed

Wang, Jenhung; Lin, Pei-Chun; Li, Shih-Chin

2014-01-01

This study assessed the ability of military aircrews to adapt to stressors when undergoing centrifuge training and determined what equipment items caused perceived stress and needed to be upgraded. We used questionnaires and the Rasch model to measure aircrew personnel's ability to adapt to centrifuge training. The measurement items were ranked by 611 military aircrew personnel. Analytical results indicated that the majority of the stress perceived by aircrew personnel resulted from the lightproof cockpit without outer reference. This study prioritized the equipment requiring updating as the lightproof cockpit design, the dim lighting of the cockpit, and the pedal design. A significant difference was found between pilot and non-pilot subjects' stress from the pedal design; and considerable association was discernible between the seat angle design and flight hours accrued. The study results provide aviators, astronauts, and air forces with reliable information as to which equipment items need to be urgently upgraded as their present physiological and psychological effects can affect the effectiveness of centrifuge training.

Personalized Offline and Pseudo-Online BCI Models to Detect Pedaling Intent

PubMed Central

Rodríguez-Ugarte, Marisol; Iáñez, Eduardo; Ortíz, Mario; Azorín, Jose M.

2017-01-01

The aim of this work was to design a personalized BCI model to detect pedaling intention through EEG signals. The approach sought to select the best among many possible BCI models for each subject. The choice was between different processing windows, feature extraction algorithms and electrode configurations. Moreover, data was analyzed offline and pseudo-online (in a way suitable for real-time applications), with a preference for the latter case. A process for selecting the best BCI model was described in detail. Results for the pseudo-online processing with the best BCI model of each subject were on average 76.7% of true positive rate, 4.94 false positives per minute and 55.1% of accuracy. The personalized BCI model approach was also found to be significantly advantageous when compared to the typical approach of using a fixed feature extraction algorithm and electrode configuration. The resulting approach could be used to more robustly interface with lower limb exoskeletons in the context of the rehabilitation of stroke patients. PMID:28744212

Utilizing anthropometric data to improve the usability of desk bikes, and influence of desk bikes on reading and typing performance

PubMed Central

Cho, Jay; Freivalds, Andris; Rovniak, Liza S.

2017-01-01

This study investigated the feasibility of using a desk bike in an office setting. Workstation measurements were introduced to accommodate 95% of the general U.S. population in using desk bikes. Reading and typing performances were compared at three different cycling conditions (no cycling, 10 and 25 watts). Thirty healthy individuals (15 female and 15 male; Age mean: 23.1, σ: 4.19) were recruited based on 5/50/95th percentile stature. Participants were required to select preferred workstation settings and perform reading and typing tasks while pedaling. According to anthropometric measurements and variability from user preference, recommended adjustable ranges of workstation settings for the general U.S. population were derived. Repeated measures ANOVA showed that pedaling had no significant effect on reading comprehension (p > .05), but had significant effect on typing performance (p < .001). A preferred level of cycling intensity was determined (mean 17.3 watts, σ: 3.69). PMID:28166871

Interaction between muscle temperature and contraction velocity affects mechanical efficiency during moderate-intensity cycling exercise in young and older women.

PubMed

Bell, Martin P; Ferguson, Richard A

2009-09-01

The effect of elevated muscle temperature on mechanical efficiency was investigated during exercise at different pedal frequencies in young and older women. Eight young (24 +/- 3 yr) and eight older (70 +/- 4 yr) women performed 6-min periods of cycling at 75% ventilatory threshold at pedal frequencies of 45, 60, 75, and 90 rpm under control and passively elevated local muscle temperature conditions. Mechanical efficiency was calculated from the ratio of energy turnover (pulmonary O(2) uptake) and mechanical power output. Overall, elevating muscle temperature increased (P < 0.05) mechanical efficiency in young (32.0 +/- 3.1 to 34.0 +/- 5.5%) and decreased (P < 0.05) efficiency in older women (30.2 +/- 5.6 to 27.9 +/- 4.1%). The different effect of elevated muscle temperature in young and older women reflects a shift in the efficiency-velocity relationship of skeletal muscle. These effects may be due to differences in recruitment patterns, as well as sarcopenic and fiber-type changes with age.

Acid secretion by the boring organ of the burrowing giant clam, Tridacna crocea.

PubMed

Hill, Richard W; Armstrong, Eric J; Inaba, Kazuo; Morita, Masaya; Tresguerres, Martin; Stillman, Jonathon H; Roa, Jinae N; Kwan, Garfield T

2018-06-01

The giant clam Tridacna crocea , native to Indo-Pacific coral reefs, is noted for its unique ability to bore fully into coral rock and is a major agent of reef bioerosion. However, T. crocea 's mechanism of boring has remained a mystery despite decades of research. By exploiting a new, two-dimensional pH-sensing technology and manipulating clams to press their presumptive boring tissue (the pedal mantle) against pH-sensing foils, we show that this tissue lowers the pH of surfaces it contacts by greater than or equal to 2 pH units below seawater pH day and night. Acid secretion is likely mediated by vacuolar-type H + -ATPase, which we demonstrate (by immunofluorescence) is abundant in the pedal mantle outer epithelium. Our discovery of acid secretion solves this decades-old mystery and reveals that, during bioerosion, T. crocea can liberate reef constituents directly to the soluble phase, rather than producing sediment alone as earlier assumed. © 2018 The Author(s).

Personalized Offline and Pseudo-Online BCI Models to Detect Pedaling Intent.

PubMed

Rodríguez-Ugarte, Marisol; Iáñez, Eduardo; Ortíz, Mario; Azorín, Jose M

2017-01-01

The aim of this work was to design a personalized BCI model to detect pedaling intention through EEG signals. The approach sought to select the best among many possible BCI models for each subject. The choice was between different processing windows, feature extraction algorithms and electrode configurations. Moreover, data was analyzed offline and pseudo-online (in a way suitable for real-time applications), with a preference for the latter case. A process for selecting the best BCI model was described in detail. Results for the pseudo-online processing with the best BCI model of each subject were on average 76.7% of true positive rate, 4.94 false positives per minute and 55.1% of accuracy. The personalized BCI model approach was also found to be significantly advantageous when compared to the typical approach of using a fixed feature extraction algorithm and electrode configuration. The resulting approach could be used to more robustly interface with lower limb exoskeletons in the context of the rehabilitation of stroke patients.

Exercise tricycle for paraplegics.

PubMed

Gföhler, M; Loicht, M; Lugner, P

1998-01-01

The work describes a tricycle that can be used by paraplegics without assistance. Paraplegics can get on and off the tricycle independently, using hydraulic adjustment of the saddle height. The two rear wheels can be swivelled with adjustable hydraulic damping, which avoids the stability problems of a standard tricycle when riding around bends. The principal driving power is assumed to be provided by functional electrical stimulation of the femoral muscles. A hub motor is integrated in the front wheel to increase the radius of action, as additional drive for cycling up gradients and in case muscle force is not sufficient. The desired drive power is adjusted by a throttle grip on the handlebar. The percentage of motor power can also be adjusted. The force applied to the pedal, the absolute angular position of the crank, and the angular velocity of the front wheel are continuously measured by a force measurement pedal and a goniometer. Based on this information, the motor and the functional electrical stimulation of the legs are controlled.

An evaluation of the Exer-Genie exerciser and the Collins pedal mode ergometer for developing physical fitness

NASA Technical Reports Server (NTRS)

Olree, H. D.

1973-01-01

Experiments that were conducted over a 52-month period showed that isometric and isotonic training on the Exer-Genie gave negligible increases in cardiorespiratory fitness whereas training on the ergometer at a programmed pulse rate increased fitness moderately.

South American plants II: taspine isolation and anti-inflammatory activity.

PubMed

Perdue, G P; Blomster, R N; Blake, D A; Farnsworth, N R

1979-01-01

Croton lechleri L. (Euphorbiaceae), a plant from the Upper Amazon Valley of Peru, yielded the alkaloid taspine. The anti-inflammatory activity of taspine hydrochloride was studied using the carrageenan-induced pedal edema method, the cotton pellet-induced granuloma method, and the adjuvant polyarthritis model.

78 FR 71998 - Airworthiness Directives; Bombardier, Inc. Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-02

... initial and repetitive [detailed or eddy current] inspections [for cracking and damage and replacement if... the detailed or eddy current inspection for cracking of the pilot-side rudder pedal tubes, specified... within 600 flight cycles thereafter. (2) If the most recent inspection was an eddy current inspection...

Development of serotonin-like immunoreactivity in the embryos and larvae of nudibranch mollusks with emphasis on the structure and possible function of the apical sensory organ.

PubMed

Kempf, S C; Page, L R; Pires, A

1997-09-29

This investigation provides a light and electron microscopic examination of the development of serotonin-like immunoreactivity and structure of the apical sensory organ (ASO) in embryos and/or larvae of four nudibranch species: Berghia verrucicornis, Phestilla sibogae, Melibe leonina, and Tritonia diomedea. Serotonin-like immunoreactivity is first expressed in somata, dendrites, and axons of a group of five distinct neurons within the ASO. These neurons extend axons into an apical neuropil, a structure that is situated centrally and immediately dorsal to the cerebral commissure. Three of these neurons possess sensory dendrites that extend through the pretrochal epithelium, each supporting two cilia at their distal ends. Later development of serotonin-like immunoreactivity includes 1) axons from the apical neuropil that extend into each of the velar lobes; 2) neuron perikarya in the cerebral and pedal ganglia; 3) axons that extend through the cerebral commissure, cerebral-pedal connectives, pedal commissure, and possibly the visceral loop connective; and 4) axons extending from each pedal ganglion into the larval foot. Ultrastructurally, the ASO can be seen to be composed of three lobes and an apical neuropil that is separately delineated from the cerebral commissure. Four cell types are present within the ASO: ciliary tuft cells, type I and type II parampullary neurons, and ampullary neurons. Immunofluorescence and 3,3' diaminobenzidine tetrahydrochloride (DAB) labeling verify that the serotonergic neurons of the ASO are type I and type II parampullary neurons. The ampullary and type I parampullary neurons possess dendrites that extend through the pretrochal epithelium. These dendrites are partitioned into three bundles, one on either side of the ciliary tuft cells and a third bundle penetrating the pretrochal epithelium centrally between the ciliary tuft cells. One serotonergic type I parampullary neuron is associated with each of these bundles. Two ampullary neurons are associated with each of the lateral dendritic bundles, while the central bundle includes only one. Ultrastructural analyses of serotonergic axonal innervation arising from the ASO agree with those determined from fluorescently labeled material. The structure of the ASO and its associated serotonergic axons suggest that the serotonergic component of this structure senses environmental stimuli affecting velar function, possibly the contractility of muscle fibers in the velar lobes. Similarities and differences among the ASOs of embryos and larvae from various invertebrate phyla may provide useful data that will assist in the reconstruction of phylogenetic relationships.

Improving safety of vulnerable road users : effectiveness of environment and in-vehicle warning systems at intermodal interchanges.

DOT National Transportation Integrated Search

2014-01-01

In 2009, there were over 114,000 fatalities and injuries in the U.S. among vulnerable road users (VRUs; pedestrians and pedal cyclists; NHTSA, 2010). 4,092 pedestrians were killed in pedestrian-vehicle crashes. Pedestrian risk at intermodal interchan...

49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

Code of Federal Regulations, 2010 CFR

2010-10-01

.... The following requirements apply to vehicles with vacuum brake assist units and vacuum brake systems. (a) Vacuum brake assist unit integrity. The vacuum brake assist unit shall demonstrate integrity as... maintained on the pedal. (1) Inspection procedure. Stop the engine and apply service brake several times to...

14 CFR 23.177 - Static directional and lateral stability.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Static directional and lateral stability. 23.177 Section 23.177 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... these tests must be appropriate to the type of airplane. The rudder pedal force must not reverse at...

Effects of prior physical exertion on tolerance to hypoxia, orthostatic stress, and physical fatigue.

DOT National Transportation Integrated Search

1982-03-01

Ten healthy men, 20-35 years old, were tested for tolerance to hypoxia, orthostatic stress, and physical fatigue after a period of rest, and, on another occasion, after a period of physical exertion. Exertion consisted of four 10-min periods of pedal...

78 FR 11609 - Special Conditions: Embraer S.A., Model EMB-550 Airplane; Landing Pitchover Condition

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-19

... automatic braking system. The applicable airworthiness regulations do not contain adequate or appropriate... with an automatic braking system. This feature is a pilot-selectable function that allows earlier braking at landing without pilot pedal input. When the autobrake system is armed before landing, it...

78 FR 9796 - Airworthiness Directives; Cessna Aircraft Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-12

... against the right steering tube assembly during rudder pedal actuation. This AD requires you to install... between the fuel return line assembly and the steering tube assembly and clearance between the fuel return...://www.cessnasupport.com . You may review copies of the referenced service information at the FAA, Small...

77 FR 50054 - Airworthiness Directives; Cessna Aircraft Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-20

... rubbing against the right steering tube assembly during full rudder pedal actuation. This proposed AD would require you to inspect the fuel return line assembly for chafing; replace the fuel return line... right steering tube assembly and the airplane structure; and adjustment as necessary. We are proposing...

77 FR 70114 - Airworthiness Directives; Cessna Aircraft Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-23

... assemblies, which were caused by the fuel return line assembly rubbing against the right steering tube assembly during full rudder pedal actuation. This AD requires you to inspect the fuel return line assembly... the fuel return line assembly and both the right steering tube assembly and the airplane structure...

77 FR 72250 - Airworthiness Directives; Cessna Aircraft Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-05

... rubbing against the right steering tube assembly during rudder pedal actuation. This proposed AD would require you to install the forward and aft fuel return line support clamps and brackets; inspect for a minimum clearance between the fuel return line assembly and the steering tube assembly and clearance...

[The development of endoscope workstation].

PubMed

Qi, L; Qi, L; Qiou, Q J; Yu, Q L

2001-01-01

This paper introduces an endoscope workstation, which solved the weak points of multimedia endoscope database used by most hospitals. The endoscope workstation was built on pedal-switch and NTFS file system. This paper also Introduces how to make program optimal and quick inputting. The workstation has promoted the efficiency of the doctor's operation.

14 CFR 25.779 - Motion and effect of cockpit controls.

Code of Federal Regulations, 2011 CFR

2011-01-01

.... Rudder Right pedal forward for nose right. (2) Secondary. Controls Motion and effect Flaps (or auxiliary lift devices) Forward for flaps up; rearward for flaps down. Trim tabs (or equivalent) Rotate to... and auxiliary controls: (1) Powerplant. Controls Motion and effect Power or thrust Forward to increase...

14 CFR 25.779 - Motion and effect of cockpit controls.

Code of Federal Regulations, 2010 CFR

2010-01-01

.... Rudder Right pedal forward for nose right. (2) Secondary. Controls Motion and effect Flaps (or auxiliary lift devices) Forward for flaps up; rearward for flaps down. Trim tabs (or equivalent) Rotate to... and auxiliary controls: (1) Powerplant. Controls Motion and effect Power or thrust Forward to increase...

30 CFR 75.1909 - Nonpermissible diesel-powered equipment; design and performance requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... board the machine, and combustible machine components; (9) A means to prevent unintentional free and... addition to those in paragraph (a): (1) A means to ensure that no stored hydraulic energy that will cause..., and accelerator pedals, controls which are of automobile orientation; (4) An audible warning device...

30 CFR 75.1909 - Nonpermissible diesel-powered equipment; design and performance requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... board the machine, and combustible machine components; (9) A means to prevent unintentional free and... addition to those in paragraph (a): (1) A means to ensure that no stored hydraulic energy that will cause..., and accelerator pedals, controls which are of automobile orientation; (4) An audible warning device...

30 CFR 75.1909 - Nonpermissible diesel-powered equipment; design and performance requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... board the machine, and combustible machine components; (9) A means to prevent unintentional free and... addition to those in paragraph (a): (1) A means to ensure that no stored hydraulic energy that will cause..., and accelerator pedals, controls which are of automobile orientation; (4) An audible warning device...

14 CFR Appendix E to Part 135 - Helicopter Flight Recorder Specifications

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Helicopter Flight Recorder Specifications E.... E Appendix E to Part 135—Helicopter Flight Recorder Specifications Parameters Range Accuracy sensor... Controls (Collective, Longitudinal Cyclic, Lateral Cyclic, Pedal) 3 Full range ±3% 2 0.5% 1 Flight Control...

The Use of a Steering Shaping Function to Improve Human Performance in By-Wire Vehicles

DTIC Science & Technology

2008-03-01

nontrivial ways. Included in the problems induced by the staffing of automated systems are biomechanical (Sirouspour & Salcudean, 2003; Sövényi...device (e.g., brake pedal ) and the actuators of the system (e.g., calipers). In this report, we are specifically interested in steer-by-wire subsystems

Stop/Start: Overview

Science.gov Websites

/Start technology conserves energy by shutting off the gasoline engine when the vehicle is at rest, such as at a traffic light, and automatically re-starting it when the driver pushes the gas pedal to go engine when pulling out from a stop and generating electricity which is stored in the battery. Main stage

14 CFR Appendix C to Part 135 - Helicopter Flight Recorder Specifications

Code of Federal Regulations, 2010 CFR

2010-01-01

... (discrete) High/low 1 Secondary—if applicable (discrete) High/low 1 Radio transmitter keying (discrete) On/off 1 Autopilot engaged (discrete) Engaged or disengaged 1 SAS status—engaged (discrete) Engaged/disengaged 1 SAS fault status (discrete) Fault/OK 1 Flight Controls Collective 4 Full range ±3% 2 1% 2 Pedal...

Prolonged Treadmill Load Carriage: Acute Injuries and Changes in Foot Anthropometry

DTIC Science & Technology

1990-06-01

keep the feet dry by wicking away foot moisture (15,16). Reynolds, et al (17) reported that antiperspirants may be a helpful measure in reducing the...Sports Medicine Digest. Vol. 11 No. 12:7, 1989. 17. Reynolds KL, Darrigrand A, Jackson R, Roberts D, Hamlet M. Effects of pedal antiperspirants on sweat

Leg Preference and Interlateral Asymmetry of Balance Stability in Soccer Players

ERIC Educational Resources Information Center

Teixeira, Luis Augusto; de Oliveira, Dalton Lustosa; Romano, Rosangela Guimaraes; Correa, Sonia Cavalcanti

2011-01-01

To examine the effect of long lasting practice on pedal behavior in sport, we compared experienced adult soccer players and nonsoccer players on leg preference in motor tasks requiring general mobilization, soccer related mobilization, and body balance stabilization. We also evaluated performance asymmetry between the right and left legs in static…

16 CFR 1512.2 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... REQUIREMENTS FOR BICYCLES Regulations § 1512.2 Definitions. For the purposes of this part: (a) Bicycle means...-wheeled vehicle with fully operable pedals and an electric motor of less than 750 watts (1 h.p.), whose... who weighs 170 pounds, is less than 20 mph. (b) Sidewalk bicycle means a bicycle with a seat height of...

Beyond Robotic Wastelands of Time: Abandoned Pedagogical Agents and "New" Pedalled Pedagogies

ERIC Educational Resources Information Center

Savin-Baden, Maggi; Tombs, Gemma; Bhakta, Roy

2015-01-01

Chatbots, known as pedagogical agents in educational settings, have a long history of use, beginning with Alan Turing's work. Since then online chatbots have become embedded into the fabric of technology. Yet understandings of these technologies are inchoate and often untheorised. Integration of chatbots into educational settings over the past…

14 CFR 29.177 - Static directional stability.

Code of Federal Regulations, 2011 CFR

2011-01-01

... pedal motion with throttle and collective controls held constant at the trim conditions specified in... control deflection for sideslip angles up to the lesser of— (1) ±25 degrees from trim at a speed of 15 knots less than the speed for minimum rate of descent varying linearly to ±10 degrees from trim at VNE...

Causal versus Diagnostic Contingencies: On Self-Deception and On the Voter’s Illusion.

DTIC Science & Technology

1983-06-01

which requires them to submerge their forearm into a chest of circulating cold water until they can no longer tolerate it. Subjects then pedaled an...Barber Human Factors Engineering Branch HQS, Department of the Army Code 1226 DAPE- MBR Pacific Missile Test Center Washington, D. C. 20310 Point Mugu

76 FR 22316 - Airworthiness Directives; Pacific Aerospace Limited Model 750XL Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-21

... pedal assemblies for cracks and incorporating a modification repair scheme if any cracks are found. You... cracks and incorporating a modification repair scheme if any cracks are found. You may obtain further... intervals not to exceed 300 hours time-in-service (TIS) until the modification repair scheme required in...

Spinal osteosarcoma in a hedgehog with pedal self-mutilation.

PubMed

Rhody, Jeffrey L; Schiller, Chris A

2006-09-01

An African pygmy hedgehog (Atelerix albiventris) was diagnosed with osteosarcoma of vertebral origin with compression of the spinal cord and spinal nerves. The only presenting sign was a self-mutilation of rear feet. Additional diagnoses included a well-differentiated splenic hemangiosarcoma, an undifferentiated sarcoma of the ascending colon, and membranoproliferative glomerulonephritis.

Relative variances of the cadence frequency of cycling under two differential saddle heights

PubMed Central

Chang, Wen-Dien; Fan Chiang, Chin-Yun; Lai, Ping-Tung; Lee, Chia-Lun; Fang, Sz-Ming

2016-01-01

[Purpose] Bicycle saddle height is a critical factor for cycling performance and injury prevention. The present study compared the variance in cadence frequency after exercise fatigue between saddle heights with 25° and 35° knee flexion. [Methods] Two saddle heights, which were determined by setting the pedal at the bottom dead point with 35° and 25° knee flexion, were used for testing. The relative variances of the cadence frequency were calculated at the end of a 5-minute warm-up period and 5 minutes after inducing exercise fatigue. Comparison of the absolute values of the cadence frequency under the two saddle heights revealed a difference in pedaling efficiency. [Results] Five minutes after inducing exercise fatigue, the relative variances of the cadence frequency for the saddle height with 35° knee flexion was higher than that for the saddle height with 25° knee flexion. [Conclusion] The current finding demonstrated that a saddle height with 25° knee flexion is more appropriate for cyclists than a saddle height with 35° knee flexion. PMID:27065522

A dromaeosaur from the Maastrichtian of James Ross Island and the Late Cretaceous Antarctic dinosaur fauna

USGS Publications Warehouse

Case, Judd A.; Martin, James E.; Reguero, Marcelo

2007-01-01

The recovery of material of a small theropod from the Early Maastrichtian, Cape Lamb Member of the Snow Hill Island Formation is an unusual occurrence from primarily marine sediments. The pedal morphology of the specimen that includes a Metatarsal II with a lateral expansion caudal to Metatarsal III, a third metatarsal that is proximally narrow and distally wide, a Metatarsal III with a distal end that is incipiently ginglymoidal and a second pedal digit with sickle-like ungual are all diagnostic of a theropod that belongs to the family of predatory dinosaurs, the Dromaeosauridae. Yet this Antarctic dromaeosaur retains plesiomorphic features in its ankle and foot morphology. As new dromaeosaur species are being recovered from the mid-Cretaceous of South America and the retention of primitive characters in the Antarctic dromaeosaur, a new biogeographic hypothesis on dromaeosaur distribution has been generated. Gondwanan dromaeosaurs are not North America immigrants into South America and Antarctica; rather they are the relicts of a cosmopolitan dromaeosaur distribution, which has been separated by the vicariant break up of Pangea and created an endemic clade of dromaeosaurs in Gondwana.

Interactions between neurons in the frontal cortex and hippocampus in cats trained to select reinforcements of different value in conditions of cholinergic deficiency.

PubMed

Dolbakyan, E E; Merzhanova, G Kh

2007-09-01

An operant food-related conditioned reflex was developed in six cats by the "active choice" protocol: short-latency pedal presses were followed by presentation of low-quality reinforcement (bread-meat mix), while long-latency pedal presses were followed by presentation of high-quality reinforcement (meat). Animals differed in terms of their food-procuring strategies, displaying "self-control," "ambivalence," or "impulsivity." Multineuron activity was recorded from the frontal cortex and hippocampus (field CA3). Cross-correlation analysis of interneuronal interactions within (local networks) and between (distributed networks) study structures showed that the numbers of interneuronal interactions in both local and distributed networks were maximal in animals with "self-control." On the background of systemic administration of the muscarinic cholinoreceptor blockers scopolamine and trihexyphenidyl, the numbers of interneuronal interactions decreased, while "common source" influences increased. This correlated with impairment of the reproduction of the selected strategy, primarily affecting the animals' self-controlled behavior. These results show that the "self-control" strategy is determined by the organization of local and distributed networks in the frontal cortex and hippocampus.

Morphine 6 glucuronide stimulates nitric oxide release in mussel neural tissues: evidence for a morphine 6 glucuronide opiate receptor subtype.

PubMed

Mantione, K; Zhu, W; Rialas, C; Casares, F; Cadet, P; Franklin, A L; Tonnesen, J; Stefano, G B

2002-03-01

We have previously demonstrated that Mytilus edulis pedal ganglia contain opiate alkaloids, i.e., morphine and morphine 6 glucuronide (M6G), as well as mu opiate receptor subtype fragments exhibiting high sequence similarity to those found in mammals. Now we demonstrate that M6G stimulates pedal ganglia constitutive nitric oxide (NO) synthase (cNOS)-derived NO release at identical concentrations and to similar peak levels as morphine. However, the classic opiate antagonist, naloxone, only blocked the ability of morphine to stimulate cNOS-derived NO release and not that of M6G. CTOP, a mu-specific antagonist, blocked the ability of M6G to induce cNOS-derived NO release as well as that of morphine, suggesting that a novel mu opiate receptor was present and selective toward M6G. In examining a receptor displacement analysis, both opiate alkaloids displaced [3H]-dihydromorphine binding to the mu opiate receptor subtype. However, morphine exhibited a twofold higher affinity, again suggesting that a novel mu opiate receptor may be present.

Control of a haptic gear shifting assistance device utilizing a magnetorheological clutch

NASA Astrophysics Data System (ADS)

Han, Young-Min; Choi, Seung-Bok

2014-10-01

This paper proposes a haptic clutch driven gear shifting assistance device that can help when the driver shifts the gear of a transmission system. In order to achieve this goal, a magnetorheological (MR) fluid-based clutch is devised to be capable of the rotary motion of an accelerator pedal to which the MR clutch is integrated. The proposed MR clutch is then manufactured, and its transmission torque is experimentally evaluated according to the magnetic field intensity. The manufactured MR clutch is integrated with the accelerator pedal to transmit a haptic cue signal to the driver. The impending control issue is to cue the driver to shift the gear via the haptic force. Therefore, a gear-shifting decision algorithm is constructed by considering the vehicle engine speed concerned with engine combustion dynamics, vehicle dynamics and driving resistance. Then, the algorithm is integrated with a compensation strategy for attaining the desired haptic force. In this work, the compensator is also developed and implemented through the discrete version of the inverse hysteretic model. The control performances, such as the haptic force tracking responses and fuel consumption, are experimentally evaluated.

Emergence of forensic podiatry--A novel sub-discipline of forensic sciences.

PubMed

Krishan, Kewal; Kanchan, Tanuj; DiMaggio, John A

2015-10-01

"Forensic podiatry is defined as the application of sound and researched podiatric knowledge and experience in forensic investigations; to show the association of an individual with a scene of crime, or to answer any other legal question concerned with the foot or footwear that requires knowledge of the functioning foot". Forensic podiatrists can contribute to forensic identification by associating the pedal evidence with the criminal or crime scene. The most common pedal evidence collected from the crime scene is in the form of footprints, shoeprints and their tracks and trails. Forensic podiatrists can establish identity of the individuals from the footprints in many ways. The analysis of bare footprints involves the identification based on the individualistic features like flat footedness, ridges, humps, creases, an extra toe, missing toe, corns, cuts, cracks, pits, deformities, and various features of the toe and heel region. All these individualistic features can link the criminal with the crime. In addition to these, parameters of body size like stature and body weight as well as sex can also be estimated by using anthropometric methods. If a series of footprints are recovered from the crime scene, then parameters of the gait analysis such as stride/step length and general movement of the criminal can be traced. Apart from these, a newly established biometric parameter of the footprints i.e. footprint ridge density can also be evaluated for personal identification. Careful analysis of the footprint ridge density can give an idea about the sex of the criminal whose footprints are recovered at the scene which can further help to reduce the burden of the investigating officer as the investigations then may be directed toward either a male suspect or a female suspect accordingly. This paper highlights various aspects of Forensic Podiatry and discusses the different methods of personal identification related to pedal evidence. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

A Wearable Multi-Channel fNIRS System for Brain Imaging in Freely Moving Subjects

PubMed Central

Piper, Sophie K.; Krueger, Arne; Koch, Stefan P.; Mehnert, Jan; Habermehl, Christina; Steinbrink, Jens; Obrig, Hellmuth; Schmitz, Christoph H.

2013-01-01

Functional near infrared spectroscopy (fNIRS) is a versatile neuroimaging tool with an increasing acceptance in the neuroimaging community. While often lauded for its portability, most of the fNIRS setups employed in neuroscientific research still impose usage in a laboratory environment. We present a wearable, multi-channel fNIRS imaging system for functional brain imaging in unrestrained settings. The system operates without optical fiber bundles, using eight dual wavelength light emitting diodes and eight electro-optical sensors, which can be placed freely on the subject's head for direct illumination and detection. Its performance is tested on N = 8 subjects in a motor execution paradigm performed under three different exercising conditions: (i) during outdoor bicycle riding, (ii) while pedaling on a stationary training bicycle, and (iii) sitting still on the training bicycle. Following left hand gripping, we observe a significant decrease in the deoxyhemoglobin concentration over the contralateral motor cortex in all three conditions. A significant task-related ΔHbO2 increase was seen for the non-pedaling condition. Although the gross movements involved in pedaling and steering a bike induced more motion artifacts than carrying out the same task while sitting still, we found no significant differences in the shape or amplitude of the HbR time courses for outdoor or indoor cycling and sitting still. We demonstrate the general feasibility of using wearable multi-channel NIRS during strenuous exercise in natural, unrestrained settings and discuss the origins and effects of data artifacts. We provide quantitative guidelines for taking condition-dependent signal quality into account to allow the comparison of data across various levels of physical exercise. To the best of our knowledge, this is the first demonstration of functional NIRS brain imaging during an outdoor activity in a real life situation in humans. PMID:23810973

The structure of the cutaneous pedal glands in the banded snail Cepaea hortensis (Müller, 1774).

PubMed

von Byern, Janek; Cyran, Norbert; Klepal, Waltraud; Rudoll, Livia; Suppan, Johannes; Greistorfer, Sophie

2018-02-01

Although gastropods have been crawling through the ocean and on the land for 60 million years, we still know very little about the sticky mucus produced in their foot. Most research has been focused on marine species in particular and, to a lesser extent, on the well-known terrestrial species Arion vulgaris and Cornu aspersum. Within this study, we aim to characterize the foot anatomy of a smaller representative of the family Helicidae, the banded snail Cepaea hortensis. We are particularly interested in the microanatomy of the foot glands, their position, and the histochemical nature of their secretory content. Characterization of the dorsal foot region of Cepaea hortensis reveals four glands, differing in their size and in the granules produced. Histochemically, three of them react positively for sugars (PAS staining and lectin affinity tests for mannose, glucose and N-acetyl-d-glucosamine) and acidic proteins (positive Alcian blue and Toluidine blue staining), indicating the presence of acidic glycosaminoglycans. The fourth gland type does not react to any of these dyes. The ventral pedal region includes two different gland types, which are positive for the presence of acidic glycoproteins, with a lectin affinity for mannose only. A comparison with Helix pomatia indicates differences regarding the number of glands and their contents. In Helix, only three gland types are described in the dorsal region of the foot, which show a similar granular appearance but nevertheless differ in their chemical composition. Congruently, there are two gland types in the ventral region in both species, whereas in Helix an additional sugar moiety is found. This raises the question whether these differences between the pedal glandular systems of both helicid species are the result of protection or size-related adaptations, as they occur in the same habitat. © 2017 Wiley Periodicals, Inc.

Stationary Apparatus Would Apply Forces of Walking to Feet

NASA Technical Reports Server (NTRS)

Hauss, Jessica; Wood, John; Budinoff, Jason; Correia, Michael; Albrecht, Rudolf

2006-01-01

A proposed apparatus would apply controlled cyclic forces to both feet for the purpose of preventing the loss of bone density in a human subject whose bones are not subjected daily to the mechanical loads of normal activity in normal Earth gravitation. The apparatus was conceived for use by astronauts on long missions in outer space; it could also be used by bedridden patients on Earth, including patients too weak to generate the necessary forces by their own efforts. The apparatus (see figure) would be a modified version of a bicycle-like exercise machine, called the cycle ergometer with vibration isolation system (CEVIS), now aboard the International Space Station. Attached to each CEVIS pedal would be a computer-controlled stress/ vibration exciter connected to the heel portion of a special-purpose pedal. The user would wear custom shoes that would amount to standard bicycle shoes equipped with cleats for secure attachment of the balls of the feet to the special- purpose pedals. If possible, prior to use of the apparatus, the human subject would wear a portable network of recording accelerometers, while walking, jogging, and running. The information thus gathered would be fed to the computer, wherein it would be used to make the exciters apply forces and vibrations closely approximating the forces and vibrations experienced by that individual during normal exercise. It is anticipated that like the forces applied to bones during natural exercise, these artificial forces would stimulate the production of osteoblasts (bone-forming cells), as needed to prevent or retard loss of bone mass. In addition to helping to prevent deterioration of bones, the apparatus could be used in treating a person already suffering from osteoporosis. For this purpose, the magnitude of the applied forces could be reduced, if necessary, to a level at which weak hip and leg bones would still be stimulated to produce osteoblasts without exposing them to the full stresses of walking and thereby risking fracture.

Endocrine disorders which manifest in the lower extremity.

PubMed

Rubenstein, S A; Boxer, M C

1985-10-01

This article has attempted to alert the podiatric medical practitioner to those endocrine disorders which have pedal manifestations. With the clinical information presented here, the podiatrist is in a unique position to identify early signs of endocrine disease. By doing so, the podiatric practitioner may play a vital role as a member of the primary care team.

Walk This Way

ERIC Educational Resources Information Center

Mason, Nick

2007-01-01

A generation ago, it was part of growing up for all kids when they biked or walked to school. But in the last 30 years, heavier traffic, wider roads and more dangerous intersections have made it riskier for students walking or pedaling. Today, fewer than 15 percent of kids bike or walk to school compared with more than 50 percent in 1969. In the…

Measuring Cycling Effort.

ERIC Educational Resources Information Center

Jahnke, Thomas; Hamson, Mike

1999-01-01

Investigates the basic mechanics of cycling with a simple reckoning of how much effort is needed from the cyclist. The work done by the cyclist is quantified when the ride is on the flat and also when pedaling uphill. Proves that by making use of the available gears on a mountain bike, cycling uphill can be accomplished without pain. (Author/ASK)

Use of Adapted Bicycles on the Learning of Conventional Cycling by Children with Mental Retardation

ERIC Educational Resources Information Center

Burt, Tammy L.; Porretta, David L.; Klein, Richard E.

2007-01-01

This study investigated the use of adapted bicycles on the acquisition, maintenance, and generalization of conventional cycling by seven children with mild mental retardation. Feedback was used in addition to the adapted bicycles and consisted of pedal rate, head position, and steering participation. A multiple probe design was used. Participants…

75 FR 71530 - Airworthiness Directives; DASSAULT AVIATION Model MYSTERE-FALCON 50 Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-24

... because this unsafe condition could result in a high speed runway excursion when the brakes are applied... pipes of the emergency brake system 2 located near the nose landing gear bearing were swapped. The swapping of these two pipes implies that when the Left Hand (LH) brake pedal is depressed, the Right Hand...

Effects of Movement, Tempo, and Gender on Steady Beat Performance of Kindergarten Children

ERIC Educational Resources Information Center

Rose, Paige

2016-01-01

The purposes of this research were to discover the effects of manual (hand) and pedal (foot) movements, tempo, and gender on steady beat accuracy. Participants (N = 119) consisted of male (n = 63) and female (n = 56) kindergarten students randomly divided into two groups, counterbalanced with regard to school, homeroom, and gender. Participants…

16 CFR Table 1 to Part 1512 - Minimum Candlepower per Incident Foot-Candle for Clear Reflector 1

Code of Federal Regulations, 2014 CFR

2014-01-01

..., and side reflectors; entrance angle in degrees 0 10 up/down 20 left/right Pedal reflectors; entrance angle in degrees 0 10 up/down 20 left/right 0.2 27.0 18.0 9.0 7.5 6.0 3.0 0.3 6.0 4.8 2.4 1.5 .28 .20...

16 CFR Table 1 to Part 1512 - Minimum Candlepower per Incident Foot-Candle for Clear Reflector 1

Code of Federal Regulations, 2011 CFR

2011-01-01

..., and side reflectors; entrance angle in degrees 0 10 up/down 20 left/right Pedal reflectors; entrance angle in degrees 0 10 up/down 20 left/right 0.2 27.0 18.0 9.0 7.5 6.0 3.0 0.3 6.0 4.8 2.4 1.5 .28 .20...

16 CFR Table 1 to Part 1512 - Minimum Candlepower per Incident Foot-Candle for Clear Reflector 1

Code of Federal Regulations, 2010 CFR

2010-01-01

..., and side reflectors; entrance angle in degrees 0 10 up/down 20 left/right Pedal reflectors; entrance angle in degrees 0 10 up/down 20 left/right 0.2 27.0 18.0 9.0 7.5 6.0 3.0 0.3 6.0 4.8 2.4 1.5 .28 .20...

16 CFR Table 1 to Part 1512 - Minimum Candlepower per Incident Foot-Candle for Clear Reflector 1

Code of Federal Regulations, 2013 CFR

2013-01-01

..., and side reflectors; entrance angle in degrees 0 10 up/down 20 left/right Pedal reflectors; entrance angle in degrees 0 10 up/down 20 left/right 0.2 27.0 18.0 9.0 7.5 6.0 3.0 0.3 6.0 4.8 2.4 1.5 .28 .20...

16 CFR Table 1 to Part 1512 - Minimum Candlepower per Incident Foot-Candle for Clear Reflector 1

Code of Federal Regulations, 2012 CFR

2012-01-01

..., and side reflectors; entrance angle in degrees 0 10 up/down 20 left/right Pedal reflectors; entrance angle in degrees 0 10 up/down 20 left/right 0.2 27.0 18.0 9.0 7.5 6.0 3.0 0.3 6.0 4.8 2.4 1.5 .28 .20...

Riding Bikes: A Pastime for Every Child

ERIC Educational Resources Information Center

Mathias, Michelle

2011-01-01

People have heard the expression "It's as easy as riding a bike." But the idea of a child with special needs balancing, steering, and pedaling a bike can seem out of reach for some; especially when he may be unable to walk unaided or hold his head up without support. Physical capabilities or stamina need not keep a child from this pleasurable…

Annual Historical Report, Calendar Year 1990

DTIC Science & Technology

1990-03-01

study the effects of antiperspirants on feet. USARIEM will provide test subjects, equipment, and considerable experience attained by accomplishing a...pilot study. Gillette will provide antiperspirant compounds and counsel. 5. The copious volume of fluid required during bypass rewarming and the...Hamlet, and D.E. Roberts. Reduction of sweat accumulation rate with pedal antiperspirants . In: Proceedings Army Science Conference, Durham, NC, June

Effects of Age on Maximal Work Capacity in Women Aged 18-48 Years.

ERIC Educational Resources Information Center

Hartung, G. Harley; And Others

Fifty-six healthy nontrained women aged 18 to 48 were tested for maximal work capacity on a bicycle ergometer. The women were divided into three age groups. A continuous step-increment bicycle ergometer work test was administered with the workload starting at 150 kpm (kilometers per minute) and 50 pedal rpm (revolutions per minute). The workload…

Methodologies to determine forces on bones and muscles of body segments during exercise, employing compact sensors suitable for use in crowded space vehicles

NASA Technical Reports Server (NTRS)

Figueroa, Fernando

1994-01-01

A complete description of an instrumented ergometer system, including the sensors, the data acquisition system, and the methodologies to calculate the kinematic parameters were initially developed at Tulane University. This work was continued by the PI at NASA Johnson Space Center, where a flight ergometer was instrumented and tested during a KC-135 Zero-Gravity flight. The sensors that form part of the system include EMG probes and accelerometers mounted on the subject using the ergometer, load cells to measure pedal forces, and encoders to measure position and orientation of the pedal (foot). Currently, data from the flight test is being analyzed and processed to calculate the kinematic parameters of the individual. The formulation developed during the initial months of the grant will be used for this purpose. The system's components are compact (all sensors are very small). A salient feature of the system and associated methodology to determine the kinematics is that although it uses accelerometers, position is not determined by integration. Position is determined by determining the angle of two frames of reference for which acceleration at one point is known in coordinates of both frames.

A Virtual Reality-Cycling Training System for Lower Limb Balance Improvement.

PubMed

Yin, Chieh; Hsueh, Ya-Hsin; Yeh, Chun-Yu; Lo, Hsin-Chang; Lan, Yi-Ting

2016-01-01

Stroke survivors might lose their walking and balancing abilities, but many studies pointed out that cycling is an effective means for lower limb rehabilitation. However, during cycle training, the unaffected limb tends to compensate for the affected one, which resulted in suboptimal rehabilitation. To address this issue, we present a Virtual Reality-Cycling Training System (VRCTS), which senses the cycling force and speed in real-time, analyzes the acquired data to produce feedback to patients with a controllable VR car in a VR rehabilitation program, and thus specifically trains the affected side. The aim of the study was to verify the functionality of the VRCTS and to verify the results from the ten stroke patients participants and to compare the result of Asymmetry Ratio Index (ARI) between the experimental group and the control group, after their training, by using the bilateral pedal force and force plate to determine any training effect. The results showed that after the VRCTS training in bilateral pedal force it had improved by 0.22 (p = 0.046) and in force plate the stand balance has also improved by 0.29 (p = 0.031); thus both methods show the significant difference.

Motorized CPM/CAM physiotherapy device with sliding-mode Fuzzy Neural Network control loop.

PubMed

Ho, Hung-Jung; Chen, Tien-Chi

2009-11-01

Continuous passive motion (CPM) and controllable active motion (CAM) physiotherapy devices promote rehabilitation of damaged joints. This paper presents a computerized CPM/CAM system that obviates the need for mechanical resistance devices such as springs. The system is controlled by a computer which performs sliding-mode Fuzzy Neural Network (FNN) calculations online. CAM-type resistance force is generated by the active performance of an electric motor which is controlled so as to oppose the motion of the patient's leg. A force sensor under the patient's foot on the device pedal provides data for feedback in a sliding-mode FNN control loop built around the motor. Via an active impedance control feedback system, the controller drives the motor to behave similarly to a damped spring by generating and controlling the amplitude and direction of the pedal force in relation to the patient's leg. Experiments demonstrate the high sensitivity and speed of the device. The PC-based feedback nature of the control loop means that sophisticated auto-adaptable CPM/CAM custom-designed physiotherapy becomes possible. The computer base also allows extensive data recording, data analysis and network-connected remote patient monitoring.

A comparative study of the electromyographic activities of lower extremity muscles during level walking and Pedalo riding

PubMed Central

Lee, DongGeon; Kim, YouJeong; Yun, JiHyeon; Jung, MiHye; Lee, GyuChang

2016-01-01

[Purpose] To analyze the electromyographic (EMG) activities of several lower extremity muscles during ground walking and pedaling using the Pedalo Reha-Bar device. [Subjects and Methods] Fifteen healthy adults aged 20–29 year participated in this study. The subjects’ surface EMG signals while walking and Pedalo Reha-Bar riding were recorded. The subjects performed 20 steps on flat ground and 20 cycles on the Pedalo Reha-Bar. During the tasks, EMG signals of the rectus femoris, biceps femoris, tibialis anterior, soleus, and gastrocnemius within a 20-second period were recorded. The mean EMG signals within the 10 seconds from 6 to 15 seconds were used for the data analysis. [Results] There was a significant increase in the bilateral use of the rectus femoris and a significant decrease in the use of the left tibialis anterior and left soleus in pedaling using the Pedalo Reha-Bar device compared to ground walking. [Conclusion] Level walking and the Pedalo Reha-Bar riding utilize different types of muscles activities. These results suggest that Pedalo Reha-Bar riding may be used for neuromuscular activation, especially of the rectus femoris. PMID:27313354

Abdominal Aortic Hemodynamics in Intermittent Claudication Patients at Rest and During Dynamic Pedaling Exercise

PubMed Central

Cheng, Christopher P.; Taylor, Charles A.; Dalman, Ronald L.

2015-01-01

Introduction Lower extremity exercise has been shown to eliminate adverse hemodynamics conditions, such as low and oscillating blood flow and wall shear stress, in the abdominal aortas of healthy young and older adults. Methods We use cine phase-contrast magnetic resonance imaging and a custom MRI-compatible exercise cycle to quantify hemodynamic changes due to pedaling exercise in patients diagnosed with intermittent claudication. Results and Conclusions With only an average heart increase of 35±18% and exercise workload of 36±16 Watts, the patients experienced approximately 3- and 6-fold increases in blood flow, and 4- and 16-fold increases in wall shear stress at the supraceliac and infrarenal aortic locations, respectively. Also, all oscillations in flow and shear stress at rest were eliminated with exercise. Claudication patients experience 3 to 4-fold lower oscillations in flow and shear stress at rest as compared to healthy age-matched controls, likely due to reduced distal arterial compliance as a result of distal atherosclerosis. The magnitude of flow and shear oscillatory indices may be good indicators of distal arterial compliance and health, and may provide predictive power for the efficacy of focal interventions. PMID:26315797

'Caterpillar right ventricle': unusual manifestation of a rare disease.

PubMed

Kalliath, Suneesh; Rajesh, Gopalan Nair

2017-01-01

A 66-year-old man presented with abdominal distension and pedal oedema for the past 10 years. He had history of right heart failure on several occasions in the past, and one of these admissions prompted referral to a cardiac specialist. On examination, he had markedly elevated jugular venous pressure with prominent 'y-descent', a tricuspid regurgitation murmur, gross ascites and pedal oedema. A full blood count, routine biochemical screen and serum bicarbonate levels were normal. Right ventricular angiogram revealed a 'caterpillar'-like aneurysm of the right ventricle (RV) apex (figure 1 arrow) with a dilated right ventricular outflow tract and significant tricuspid regurgitation with a dilated right atrium (see online supplementary video 1). Figure 1 A cine angiographic frame of the right ventricle in posteroanterior view, showing a 'caterpillar'-like right ventricle aneurysm (arrow). 10.1136/heartasia-2017-010957.supp3Supplementary file 3. On the basis of the clinical and right ventriculography features, what is the most likely diagnosis for this patient?Arrhythmogenic right ventricular cardiomyopathy (ARVC)Right ventricular endomyocardial fibrosis (RV-EMF) with an RV aneurysmCardiac sarcoidosisCongenital diverticulum of the right ventricle.

Construction of an isokinetic eccentric cycle ergometer for research and training.

PubMed

Elmer, Steven J; Martin, James C

2013-08-01

Eccentric cycling serves a useful exercise modality in clinical, research, and sport training settings. However, several constraints can make it difficult to use commercially available eccentric cycle ergometers. In this technical note, we describe the process by which we built an isokinetic eccentric cycle ergometer using exercise equipment modified with commonly available industrial parts. Specifically, we started with a used recumbent cycle ergometer and removed all the original parts leaving only the frame and seat. A 2.2 kW electric motor was attached to a transmission system that was then joined with the ergometer. The motor was controlled using a variable frequency drive, which allowed for control of a wide range of pedaling rates. The ergometer was also equipped with a power measurement device that quantified work, power, and pedaling rate and provided feedback to the individual performing the exercise. With these parts along with some custom fabrication, we were able to construct an isokinetic eccentric cycle ergometer suitable for research and training. This paper offers a guide for those individuals who plan to use eccentric cycle ergometry as an exercise modality and wish to construct their own ergometer.

Opiate-like substances in an invertebrate, an opiate receptor on invertebrate and human immunocytes, and a role in immunosuppression.

PubMed Central

Stefano, G B; Digenis, A; Spector, S; Leung, M K; Bilfinger, T V; Makman, M H; Scharrer, B; Abumrad, N N

1993-01-01

The presence of morphine-like and codeine-like substances was demonstrated in the pedal ganglia, hemolymph, and mantle tissues of the mollusc Mytilus edulis. The pharmacological activities of the endogenous morphine-like material resemble those of authentic morphine. Both substances were found to counteract, in a dose-dependent manner, the stimulatory effect of tumor necrosis factor alpha or interleukin 1 alpha on human monocytes and Mytilus immunocytes, when added simultaneously to the incubation medium. The immunosuppressive effect of this opiate material expresses itself in a lowering of chemotactic activity, cellular velocity, and adherence. Codeine mimics the activity of authentic morphine, but only at much higher concentrations. Specific high-affinity receptor sites (mu 3) for morphine have been identified on human monocytes and Mytilus immunocytes. In Mytilus recovering from experimentally induced stress, the return of "altered" immunocytes to a more inactive state appears to be due to a significant rise in the content of morphine-like material in the pedal ganglia and hemolymph at this time. Thus, morphine may have a role in calming or terminating the state of immune alertness. PMID:8248214

Low speed hybrid generalized predictive control of a gasoline-propelled car.

PubMed

Romero, M; de Madrid, A P; Mañoso, C; Milanés, V

2015-07-01

Low-speed driving in traffic jams causes significant pollution and wasted time for commuters. Additionally, from the passengers׳ standpoint, this is an uncomfortable, stressful and tedious scene that is suitable to be automated. The highly nonlinear dynamics of car engines at low-speed turn its automation in a complex problem that still remains as unsolved. Considering the hybrid nature of the vehicle longitudinal control at low-speed, constantly switching between throttle and brake pedal actions, hybrid control is a good candidate to solve this problem. This work presents the analytical formulation of a hybrid predictive controller for automated low-speed driving. It takes advantage of valuable characteristics supplied by predictive control strategies both for compensating un-modeled dynamics and for keeping passengers security and comfort analytically by means of the treatment of constraints. The proposed controller was implemented in a gas-propelled vehicle to experimentally validate the adopted solution. To this end, different scenarios were analyzed varying road layouts and vehicle speeds within a private test track. The production vehicle is a commercial Citroën C3 Pluriel which has been modified to automatically act over its throttle and brake pedals. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

Good Teachers (the Movie You Will Never See)

ERIC Educational Resources Information Center

Gillard, Colleen

2012-01-01

It began with a trip to the cinema to see Cameron Diaz in her new comedy, "Bad Teacher." It was a bad choice. Not a great flick, but as a parody of bad employees, in terms of things that can get one fired--drugs, alcohol , cheating, foul language, inappropriate sexual behavior--Diaz slams pedal to the metal. She nips out of airline booze bottles…

Afghanistan: Politics, Elections, and Government Performance

DTIC Science & Technology

2010-02-19

States, U.N. Secretary General Ban Ki Moon (visiting Kabul), and several governments congratulated Karzai on the victory. U.S. officials, including...Ban Ki Moon of Galbraith, who had openly accused UNAMA head Kai Eide of soft-pedaling on the fraud charges and siding with Karzai. Galbraith has...of Transport and Aviation; and (10) Sultan Hussein Hesari, Minister of Urban Development. 2010 Parliamentary Elections/Election Law On January 2

The PEDALS Stationary Cycling Intervention and Health-Related Quality of Life in Children with Cerebral Palsy: A Randomized Controlled Trial

ERIC Educational Resources Information Center

DeMuth, Sharon K.; Knutson, Loretta M.; Fowler, Eileen G.

2012-01-01

Aim: The aim of this study was to assess health-related quality of life (HRQOL) following a stationary cycling intervention in children with cerebral palsy (CP). Method: This was a phase I multisite randomized controlled trial with single blinding. HRQOL was evaluated using the Pediatric Quality of Life Inventory SF15 (PedsQL; children) and…

75 FR 55492 - Airworthiness Directives; Eurocopter France Models SA330F, SA330G, and SA330J Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-13

... helicopter, the copilot set the position beyond the end limit (``tall pilot'' position). This resulted in the... determined that the Loctite bond on the ``tall pilot'' stop nut was damaged, most likely due to aging of the... position beyond the end limit (``tall pilot'' position). This resulted in the separation of the pedal...

14 CFR Appendix E to Part 135 - Helicopter Flight Recorder Specifications

Code of Federal Regulations, 2011 CFR

2011-01-01

... Keying On-Off (Discrete) 1 0.25 sec Power in Each Engine: Free Power Turbine Speed and Engine Torque 0-130% (power Turbine Speed) Full range (Torque) ±2% 1 speed 1 torque (per engine) 0.2% 1 to 0.4% 1 Main... Controls (Collective, Longitudinal Cyclic, Lateral Cyclic, Pedal) 3 Full range ±3% 2 0.5% 1 Flight Control...

14 CFR Appendix E to Part 135 - Helicopter Flight Recorder Specifications

Code of Federal Regulations, 2014 CFR

2014-01-01

... Keying On-Off (Discrete) 1 0.25 sec Power in Each Engine: Free Power Turbine Speed and Engine Torque 0-130% (power Turbine Speed) Full range (Torque) ±2% 1 speed 1 torque (per engine) 0.2% 1 to 0.4% 1 Main... Controls (Collective, Longitudinal Cyclic, Lateral Cyclic, Pedal) 3 Full range ±3% 2 0.5% 1 Flight Control...

14 CFR Appendix E to Part 135 - Helicopter Flight Recorder Specifications

Code of Federal Regulations, 2012 CFR

2012-01-01

... Keying On-Off (Discrete) 1 0.25 sec Power in Each Engine: Free Power Turbine Speed and Engine Torque 0-130% (power Turbine Speed) Full range (Torque) ±2% 1 speed 1 torque (per engine) 0.2% 1 to 0.4% 1 Main... Controls (Collective, Longitudinal Cyclic, Lateral Cyclic, Pedal) 3 Full range ±3% 2 0.5% 1 Flight Control...

26. July 1974. BENCH SHOP, VIEW LOOKING SOUTH, SHOWING THE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

26. July 1974. BENCH SHOP, VIEW LOOKING SOUTH, SHOWING THE BORING MACHINE PURCHASED IN 1885. THE BIT MAY BE LOWERED BY THE HANGING LINKAGE OR THE TABLE RAISED BY THE FOOT PEDAL. NOTICE THE CHASE FOR THE BELTS, BUILT NO LESS CAREFULLY THAN THE MACHINE ITSELF. - Gruber Wagon Works, Pennsylvania Route 183 & State Hill Road at Red Bridge Park, Bernville, Berks County, PA

The Seated Soldier Study: Posture and Body Shape in Vehicle Seats

DTIC Science & Technology

2013-10-31

ergonomics and safety assessments. UNCLASSIFIED UNCLASSIFIED 3 INTRODUCTION The design of seats and interiors for a wide variety of...DHMs) began to be used for ergonomic assessments and design of vehicle interiors and seats , particularly for driver workstation layout (Chaffin 2001...in a vehicle mockup by varying the steering wheel position relative to the pedals. The participants adjusted the seat to obtain a comfortable

Trace element profiles of the sea anemone Anemonia viridis living nearby a natural CO2 vent

PubMed Central

Borell, Esther M.; Fine, Maoz; Shaked, Yeala

2014-01-01

Ocean acidification (OA) is not an isolated threat, but acts in concert with other impacts on ecosystems and species. Coastal marine invertebrates will have to face the synergistic interactions of OA with other global and local stressors. One local factor, common in coastal environments, is trace element contamination. CO2 vent sites are extensively studied in the context of OA and are often considered analogous to the oceans in the next few decades. The CO2 vent found at Levante Bay (Vulcano, NE Sicily, Italy) also releases high concentrations of trace elements to its surrounding seawater, and is therefore a unique site to examine the effects of long-term exposure of nearby organisms to high pCO2 and trace element enrichment in situ. The sea anemone Anemonia viridis is prevalent next to the Vulcano vent and does not show signs of trace element poisoning/stress. The aim of our study was to compare A. viridis trace element profiles and compartmentalization between high pCO2 and control environments. Rather than examining whole anemone tissue, we analyzed two different body compartments—the pedal disc and the tentacles, and also examined the distribution of trace elements in the tentacles between the animal and the symbiotic algae. We found dramatic changes in trace element tissue concentrations between the high pCO2/high trace element and control sites, with strong accumulation of iron, lead, copper and cobalt, but decreased concentrations of cadmium, zinc and arsenic proximate to the vent. The pedal disc contained substantially more trace elements than the anemone’s tentacles, suggesting the pedal disc may serve as a detoxification/storage site for excess trace elements. Within the tentacles, the various trace elements displayed different partitioning patterns between animal tissue and algal symbionts. At both sites iron was found primarily in the algae, whereas cadmium, zinc and arsenic were primarily found in the animal tissue. Our data suggests that A. viridis regulates its internal trace element concentrations by compartmentalization and excretion and that these features contribute to its resilience and potential success at the trace element-rich high pCO2 vent. PMID:25250210

INTERVENTION AT THE FOOT-SHOE-PEDAL INTERFACE IN COMPETITIVE CYCLISTS

PubMed Central

Vicenzino, Bill; Sisto, Sue Ann

2016-01-01

ABSTRACT Background Competitive cyclists are susceptible to injury from the highly repetitive nature of pedaling during training and racing. Deviation from an optimal movement pattern is often cited as a factor contributing to tissue stress with specific concern for excessive frontal plane knee motion. Wedges and orthoses are increasingly used at the foot-shoe-pedal-interface (FSPI) in cycling shoes to alter the kinematics of the lower limb while cycling. Determination of the effect of FSPI alteration on cycling kinematics may offer a simple, inexpensive tool to reduce anterior knee pain in recreational and competitive cyclists. There have been a limited number of experimental studies examining the effect of this intervention in cyclists, and there is little agreement upon which FSPI interventions can prevent or treat knee injury. The purpose of this review is to provide a broader review of the literature than has been performed to date, and to critically examine the literature examining the evidence for FSPI intervention in competitive cyclists. Methods Current literature examining the kinematic response to intervention at the FSPI while cycling was reviewed. A multi-database search was performed in PubMed, EBSCO, Scopus, CINAHL and SPORTdiscus. Eleven articles were reviewed, and a risk of bias assessment performed according to guidelines developed by the Cochrane Bias Methods Group. Papers with a low risk of bias were selected for review, but two papers with higher risk of bias were included as there were few high quality studies available on this topic. Results Seven of the eleven papers had low bias in sequence generation i.e. random allocation to the test condition, only one paper had blinding to group allocation, all papers had detailed but non-standardized methodology, and incomplete data reporting, but were generally free of other bias sources. Conclusions Wedges and orthoses at the FSPI alter kinematics of the lower limb while cycling, although conclusions about their efficacy and response to long-term use are limited. Further high quality experimental studies are needed examining cyclists using standardized methodology and products currently used to alter SPFI function. Level of Evidence 3 PMID:27525187

Comparison of Plasma Levels of Renin, Vasopressin and Atrial Natriuretic Peptide in Hypertensive Amlodipine Induced Pedal Oedema, Non-Oedema and Cilnidipine Treated Patients

PubMed Central

Shetty, Kiran; Rao, Pragna; Ballal, Mamatha; Kiran, Amruth; Reddy, Sravan; Pai, Umesh; Samanth, Jyothi

2017-01-01

Introduction Amlodipine is a third generation dihydropyridine group of calcium channel blocker and having an excellent antihypertensive profile. Pedal Oedema (PE) is the major drawback of amlodipine therapy and the incidence of Amlodipine Induced Pedal Oedema (AIPE) has been found significantly high. Several neurohumoral factors influence the incidence of oedema. Aim We aimed to compare the plasma levels of renin, vasopressin and atrial natriuretic peptide in hypertensive AIPE, non-oedema and cilnidipine treated patients. Materials and Methods The present prospective, interventional study was conducted on 104 mild to moderate hypertensive patients (52 patients in each group), after due consideration of eligibility criteria. Plasma Renin (PR), Vasopressin (VAS), and the Atrial Natriuretic Peptide (ANP) was estimated by ELISA test and compared between the AIPE, Amlodipine Treated Non-Oedema (ATNE) in Phase I, and AIPE and Cilnidipine Treated (CT) Groups in Phase II. Results The clinical and demographic parameters were matched. PR was significantly high in AIPE group than the ATNE, and it was significantly reduced after one month follow up with the substitution of cilnidipine. The median (IQR) value of PR was 4.87 (3.58, 6.63), 3.50 (1.44, 5.47) and 2.66 (1.02, 5.66) ng/ml in AIPE, ATNE, CT group respectively. VAS was significantly high in AIPE group than ATNE, and it significantly reduced after one month follow up with CT group. The median (IQR) value of vasopressin was 6.78 (2.55, 9.16), 2.58 (1.61, 5.73) and 2.50 (1.23, 5.00) ng/ml in AIPE, ATNE and CT groups respectively. There was no significant difference seen in plasma ANP levels between the groups. The p-value was <0.05 which is statistically significant. Conclusion The AIPE may not be volume overload or fluid retention; it may be due to persistent raise in adrenergic activity followed chronic amlodipine therapy. Cilnidipine relatively suppresses the sympathetic activity, and completely resolves the AIPE by significantly reducing PR and VAS levels. ANP did not show a difference between groups. Cilnidipine is the suitable alternative antihypertensive drug for AIPE patients. PMID:28764190

The toothless pterosaur Jidapterus edentus (Pterodactyloidea: Azhdarchoidea) from the Early Cretaceous Jehol Biota and its paleoecological implications

PubMed Central

Wu, Wen-Hao; Zhou, Chang-Fu; Andres, Brian

2017-01-01

Background In the Early Cretaceous Jehol Biota, the toothless pterosaurs flourished with the chaoyangopterids and tapejarids playing a key role in understanding the early diversity and evolution of the Azhdarchoidea. Unlike the more diverse tapejarids, the rarer chaoyangopterids are characterized by a long and low rostrum, supporting a close relationship with the huge azhdarchids. Unfortunately, our knowledge is still limited in the osteology, paleoecology, and taxonomy of the Chaoyangopteridae. As one of the best preserved skeletons, the type and only specimen of Jidapterus edentus provides an opportunity to understand the morphology and paleoecology of the chaoyangopterids. Results Our study of the osteology of Jidapterus edentus reveals valuable information about the morphology of the Chaoyangopteridae such as a rostrum with a curved dorsal profile, high Rostral Index (RI), larger angle between the dorsal and postorbital processes of the jugal, sequentially shorter fourth to seventh cervical vertebrae, sternum with a plate wider than long, contact of the metacarpal I with the distal syncarpal, pneumatic foramen on first wing phalanx, hatchet-like postacetabular process with unconstricted neck and small dorsal process, distinctly concave anterior margin of pubis, subrectangular pubic plate with nearly parallel anterior and posterior margins, longer proximal phalanges of pedal digits III and IV, as well as reduced and less curved pedal unguals. These features further support the validity of Jidapterus edentus as a distinct species and the close relationship of the chaoyangopterids with the azhdarchids. Paleoecologically, the chaoyangopterids are probably like the azhdarchids, more terrestrial than the contemporaneous and putatively arboreal tapejarids, which may have been limited to the forest-dominated ecosystem of the Jehol Biota. Discussion The osteology of Jidapterus edentus further supports the close relationship of the Chaoyangopteridae with the Azhdarchidae in sharing a high RI value and reduced and mildly-curved pedal unguals, and it also implies a possible paleoecological similarity in their terrestrial capability. Combined with the putatively arboreal and herbivorous tapejarids, this distinct lifestyle of the chaoyangopterids provides new insights into the diversity of pterosaurs in the ecosystem of the Jehol Biota. PMID:28950013

Two new Phrynobatrachus species (Amphibia: Anura: Phrynobatrachidae) from the Republic of the Congo.

PubMed

Rödel, Mark-Oliver; Burger, Marius; Zassi-Boulou, Ange Ghislain; Emmrich, Mike; Penner, Johannes; Barej, Michael F

2015-10-14

We describe two new species of puddle frogs, genus Phrynobatrachus, from the south-western Republic of the Congo. One of them, P. horsti sp. nov., occurs also in neighbouring Gabon and is morphologically most similar to the Cameroonian P. ruthbeateae. It differs from the latter species by smaller males with longer thighs and shanks. The new species comprises various colour morphs but always has less conspicuous black borders between flanks and belly than P. ruthbeateae. The distinct and large black axillary blotch of P. ruthbeateae is either much smaller in P. horsti sp. nov., or broken into numerous irregularly shaped smaller dots. Similarly, a black transversal line at the anterior ventral border of thighs and the black face mask is less distinct and irregularly delimitated in P. horsti sp. nov. when compared to P. ruthbeateae. The mean genetic difference in the sampled region of the 16S rRNA gene between P. horsti sp. nov. and 40 other western African congeners range from 3.66-18.10%. The second new species, P. mayokoensis sp. nov., differs from all other known congeners by the combination of a compact and warty body, the absence of a spiny eyelid tubercle and pedal webbing, a conspicuous black triangle on throat and anterior part of the belly, and a distinct large red blotch on the anterior-proximal surface of the thighs. It exhibited a mean genetic difference in the 16S rRNA to 40 other western African congeners ranging from 1.34-16.98%. The genetically most similar sequence stems from a GenBank entry of a Gabonese frog, determined as P. ogoensis. A comparison of the new species with P. ogoensis syntypes confirmed their specific distinctiveness, most convincingly underlined by the absence of pedal webbing in the new species and the pronounced pedal webbing in P. ogoensis. The GenBank entry thus most likely is based on a misidentification and P. mayokoensis sp. nov. may also occur in neighbouring Gabon. The discovery of the two new frog species is further evidence of the huge gap in our knowledge concerning the species richness in the Guineo-Congolian rainforests.

No Need for Training Wheels: Ideas for Including Balance Bikes in Elementary Physical Education

ERIC Educational Resources Information Center

Becker, Andrew; Jenny, Seth E.

2017-01-01

Although it was invented nearly two centuries ago in Germany, the balance bike is only now beginning to make its presence known in the United States. A balance bike is a bicycle with no pedals- propelled by running or walking--and is designed to teach young children how to ride a bike in less time by allowing them to practice balance and steering…

Human-Robot Interface: Issues in Operator Performance, Interface Design, and Technologies

DTIC Science & Technology

2006-07-01

and the use of lightweight portable robotic sensor platforms. 5 robotics has reached a point where some generalities of HRI transcend specific...displays with control devices such as joysticks, wheels, and pedals (Kamsickas, 2003). Typical control stations include panels displaying (a) sensor ...tasks that do not involve mobility and usually involve camera control or data fusion from sensors Active search: Search tasks that involve mobility

73. VIEW OF LAUNCH OPERATOR AND LAUNCH ANAYLST PANELS LOCATED ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

73. VIEW OF LAUNCH OPERATOR AND LAUNCH ANAYLST PANELS LOCATED NEAR CENTER OF SOUTH WALL OF SLC-3E CONTROL ROOM. FROM LEFT TO RIGHT ON WALL IN BACKGROUND: COMMUNICATIONS HEADSET AND FOOT PEDAL IN FORGROUND. ACCIDENT REPORTING EMERGENCY NOTIFICATION SYSTEM TELEPHONE, ATLAS H FUEL COUNTER, AND DIGITAL COUNTDOWN CLOCK. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Operations Building, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

New Integrated Testing System for the Validation of Vehicle-Snow Interaction Models

DTIC Science & Technology

2010-08-06

are individual wheel speeds, accelerator pedal position, vehicle speed, yaw rate, lateral acceleration, steering wheel angle and brake ...forces and moments at each wheel center, vehicle body slip angle , speed, acceleration, yaw rate, roll, and pitch. The profilometer has a 3-D scanning...Stability Program. The test vehicle provides measurements that include three forces and moments at each wheel center, vehicle body slip angle , speed

Implementation of Active Workstations in University Libraries-A Comparison of Portable Pedal Exercise Machines and Standing Desks.

PubMed

Bastien Tardif, Camille; Cantin, Maude; Sénécal, Sylvain; Léger, Pierre-Majorique; Labonté-Lemoyne, Élise; Begon, Mickael; Mathieu, Marie-Eve

2018-06-12

Sedentary behaviors are an important issue worldwide, as prolonged sitting time has been associated with health problems. Recently, active workstations have been developed as a strategy to counteract sedentary behaviors. The present study examined the rationale and perceptions of university students’ and staff following their first use of an active workstation in library settings. Ninety-nine volunteers completed a self-administered questionnaire after using a portable pedal exercise machine (PPEM) or a standing desk (SD). Computer tasks were performed on the SD ( p = 0.001) and paperwork tasks on a PPEM ( p = 0.037) to a larger extent. Men preferred the SD and women chose the PPEM ( p = 0.037). The appreciation of the PPEM was revealed to be higher than for the SD, due to its higher scores for effective, useful, functional, convenient, and comfortable dimensions. Younger participants (<25 years of age) found the active workstation more pleasant to use than older participants, and participants who spent between 4 to 8 h per day in a seated position found active workstations were more effective and convenient than participants sitting fewer than 4 h per day. The results of this study are a preliminary step to better understanding the feasibility and acceptability of active workstations on university campuses.

Investigating pianists' individuality in the performance of five timbral nuances through patterns of articulation, touch, dynamics, and pedaling

PubMed Central

Bernays, Michel; Traube, Caroline

2014-01-01

Timbre is an essential expressive feature in piano performance. Concert pianists use a vast palette of timbral nuances to color their performances at the microstructural level. Although timbre is generally envisioned in the pianistic community as an abstract concept carried through an imaged vocabulary, performers may share some common strategies of timbral expression in piano performance. Yet there may remain further leeway for idiosyncratic processes in the production of piano timbre nuances. In this study, we examined the patterns of timbral expression in performances by four expert pianists. Each pianist performed four short pieces, each with five different timbral intentions (bright, dark, dry, round, and velvety). The performances were recorded with the high-accuracy Bösendorfer CEUS system. Fine-grained performance features of dynamics, touch, articulation and pedaling were extracted. Reduced PCA performance spaces and descriptive performance portraits confirmed that pianists exhibited unique, specific profiles for different timbral intentions, derived from underlying traits of general individuality, while sharing some broad commonalities of dynamics and articulation for each timbral intention. These results confirm that pianists' abstract notions of timbre correspond to reliable patterns of performance technique. Furthermore, these effects suggest that pianists can express individual styles while complying with specific timbral intentions. PMID:24624099

Full suspension mountain bike improves off-road cycling performance.

PubMed

Nishii, T; Umemura, Y; Kitagawa, K

2004-12-01

The purpose of the present study was to determine the effects of suspension systems on the cycling performance of cyclists during off-road bicycling. Eight elite male cyclists (67.8+/-5.8 ml/min/kg of (.-)VO(2max)) performed 30-minute riding tests on bicycles with 2 different suspension setups: front suspension (FS) and front and rear suspension (FRS). Heart rate, blood lactate concentration, pedaling power, cadence, cycling velocity, and completed distance during the trial were measured creatin kinase (CK), lactic dehydrogenase (LDH) and glutamic-oxaloacetic transaminase (GOT) were measured before and after the trials. The average cadence during the trial was significantly higher (p<0.05) with the FRS (73.6+/-6.1 rpm) than the FS (70.2+/-6.2 rpm). Subjects rode significantly faster (p<0.05) on FRS (24.1+/-2.6 km/h) than FS bikes (22.9+/-2.4 km/h), although no significant difference was observed in pedaling power (240.7+/-26.6 W vs 242.2+/-28.8 W, FS vs FRS, respectively). Serum creatin kinase increased significantly (p<0.05) at 24 h after the trial when cyclists exercised with the FS bike. We conclude that the FRS improved cycling performance over rough terrain. FRS might therefore be more suitable for cross-country mountain bike races.

Time course of blood pressure changes immediately after maximal exercise.

PubMed

Nakahara, H; Miyamoto, T; Nakanishi, Y; Kinoshita, H

2006-12-01

The aim of this study was to investigate the effect of exhaustive exercise on the time course of arterial blood pressure (BP) and heart rate (HR) during upright resting (inactive) and loadless pedaling (active) recovery from a bicycle exercise to exhaustion. The subjects were 11 healthy normotensive males. Systolic, diastolic and mean BP, and HR were recorded every 20 s for the initial 6 min of the recovery period. The time course of all BP measures during inactive and active recovery was characterized by a marked and sudden drop during the initial 20-s period, followed by a quick rise. This was followed by a gradual decline till the end of the recovery period. The time course of HR recovery, on the other hand, exhibited a smooth decline without the initial drop. With active recovery, the initial drop of diastolic and mean BP was less than the inactive recovery. After the 20 s period, the diastolic BP and HR were kept slightly higher with the active recovery than the inactive recovery. A sudden drop of the BP occurred at the initial recovery period of postcycle exercise to exhaustion though HR did not show such a change. The initial BP drop could be attenuated by the actively pedaling the cycle without load.

"Further Effects"

NASA Astrophysics Data System (ADS)

Kinigstein, Steven Michael

In writing Further Effects, I intended to illustrate the benefits that are to be had from the use of effects - processing, when applied at the compositional level, rather than as a post-compositional afterthought. When effects are used creatively in the compositional stage, they will influence the very nature of a piece. They are capable of expressing rhythmic and metric ideas. They can alter the natural timbre of an instrument. This can be done on levels of abstraction ranging from discreet subtlety to disguise beyond recognition. There is one effect (known as "pitch shift.") that allows an instrument to play pitches that are well outside of its range. In Further Effects, I direct the performers to use a volume pedal (which I view as a tool, rather than an effect) for the broadened creative use of dynamics that it so efficiently grants. The use of an effects processor and volume pedal creates a need for ancillary equipment. An amplifier, cables, and an electric hook-up (a microphone or a pickup) will be required for each instrument. While an amplifier serves to project the processed sound, there must also be a device or method to suppress unprocessed sound. A great deal of thought and work goes into the use of effects; yet I feel it is wasteful to use this musical resource merely as post-compositional decoration.

Central and peripheral hemodynamics in exercising humans: leg vs arm exercise.

PubMed

Calbet, J A L; González-Alonso, J; Helge, J W; Søndergaard, H; Munch-Andersen, T; Saltin, B; Boushel, R

2015-12-01

In humans, arm exercise is known to elicit larger increases in arterial blood pressure (BP) than leg exercise. However, the precise regulation of regional vascular conductances (VC) for the distribution of cardiac output with exercise intensity remains unknown. Hemodynamic responses were assessed during incremental upright arm cranking (AC) and leg pedalling (LP) to exhaustion (Wmax) in nine males. Systemic VC, peak cardiac output (Qpeak) (indocyanine green) and stroke volume (SV) were 18%, 23%, and 20% lower during AC than LP. The mean BP, the rate-pressure product and the associated myocardial oxygen demand were 22%, 12%, and 14% higher, respectively, during maximal AC than LP. Trunk VC was reduced to similar values at Wmax. At Wmax, muscle mass-normalized VC and fractional O2 extraction were lower in the arm than the leg muscles. However, this was compensated for during AC by raising perfusion pressure to increase O2 delivery, allowing a similar peak VO2 per kg of muscle mass in both extremities. In summary, despite a lower Qpeak during arm cranking the cardiovascular strain is much higher than during leg pedalling. The adjustments of regional conductances during incremental exercise to exhaustion depend mostly on the relative intensity of exercise and are limb-specific. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

[Effect of loading suit "Penguin" on human metabolism during movements].

PubMed

Barer, A S; Kozlovskaia, I B; Tikhomirov, E P; Sinigin, V M; Letkova, L I

1998-01-01

Additional energy expenses due to stretching of the elastic elements of anti-loading suit (ALS) "Penguin" as a whole (shoulders-feet) or only its lower part (waist-feet) in the course of cyclic leg movements were measured in five female and five male volunteers. ALS design enabled tensometric monitoring of efforts applied to specific elastic elements, and total efforts applied to the shoulder or pelvic girdles separately. Energy spend were determined with the indirect calorimetric techniques from the data of the expired air analysis. Registered were electromyograms of m. longus spinae, femoral extensor (m. biceps femoris) and femoral flexor (m. rectus femoris), and m. gastrocnemius. On the first stage, bicycle ergometer was pedaled w/o loading with a frequency of 60 cycles/min. The next stage included testing by incremental loading in which pedaling ceased at the pulse rate of 150/min. Results of the experiments that did not require stretching elastic parts of the suit and in which the total strain effort made up 20 to 25 kg and 15 to 16 kg by males and females, respectively, were compared. It was ascertained that ALS enhanced metabolism during motion by 20 to 30%; however, there was no significant difference in energy expenses when loaded by the whole suit or only its lower part.

Power output of field-based downhill mountain biking.

PubMed

Hurst, Howard Thomas; Atkins, Stephen

2006-10-01

The purpose of this study was to assess the power output of field-based downhill mountain biking. Seventeen trained male downhill cyclists (age 27.1 +/- 5.1 years) competing nationally performed two timed runs of a measured downhill course. An SRM powermeter was used to simultaneously record power, cadence, and speed. Values were sampled at 1-s intervals. Heart rates were recorded at 5-s intervals using a Polar S710 heart rate monitor. Peak and mean power output were 834 +/- 129 W and 75 +/- 26 W respectively. Mean power accounted for only 9% of peak values. Paradoxically, mean heart rate was 168 +/- 9 beats x min(-1) (89% of age-predicted maximum heart rate). Mean cadence (27 +/- 5 rev x min(-1)) was significantly related to speed (r = 0.51; P < 0.01). Analysis revealed an average of 38 pedal actions per run, with average pedalling periods of 5 s. Power and cadence were not significantly related to run time or any other variable. Our results support the intermittent nature of downhill mountain biking. The poor relationships between power and run time and between cadence and run time suggest they are not essential pre-requisites to downhill mountain biking performance and indicate the importance of riding dynamics to overall performance.

PILOT RESULTS ON FORWARD COLLISION WARNING SYSTEM EFFECTIVENESS IN OLDER DRIVERS

PubMed Central

Lester, Benjamin D.; Sager, Lauren N.; Dawson, Jeffrey; Hacker, Sarah D.; Aksan, Nazan; Rizzo, Matthew; Kitazaki, Satoshi

2016-01-01

Summary Advanced Driver Assistance Systems (ADAS) have largely been developed with a “one-size-fits-all” approach. This approach neglects the large inter-individual variability in perceptual and cognitive abilities that affect aging ADAS users. We investigated the effectiveness of a forward collision warning (FCW) with fixed response parameters in young and older drivers with differing levels of cognitive functioning. Drivers responded to a pedestrian stepping into the driver’s path on a simulated urban road. Behavioral metrics included response times (RT) for pedal controls and two indices of risk penetration (e.g., maximum deceleration and minimum time-to-collision (TTC)). Older drivers showed significantly slower responses at several time points compared to younger drivers. The FCW facilitated response times (RTs) for older and younger drivers. However, older drivers still showed smaller safety gains compared to younger drivers at accelerator pedal release and initial brake application when the FCW was active. No significant differences in risk metrics were observed within the condition studied. The results demonstrate older drivers likely differ from younger drivers using a FCW with a fixed parameter set. Finally, we briefly discuss how future research should examine predictive relationships between domains of cognitive functioning and ADAS responses to develop parameter sets to fit the individual. PMID:27135061

76 FR 28914 - Airworthiness Directives; Airbus Model A300 B4-600, B4-600R, and F4-600R Series Airplanes, and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-19

... of the rudder system design. Rudder pedal sensitivity on Model A300-600 and A310 series airplanes is... B4-600, B4-600R, and F4-600R Series Airplanes, and Model C4-605R Variant F Airplanes (Collectively Called A300-600 Series Airplanes); and Model A310 Series Airplanes AGENCY: Federal Aviation...

Pedal Power Goes Global. Twelfth Grade Economics Lesson Plan. Schools of California Online Resources for Education (SCORE): Connecting California's Classrooms to the World.

ERIC Educational Resources Information Center

Antillas, Madeline

Many factors must be considered when a company decides to market its product in another country. It must research the targeted country to determine if there is a demand for the product, decide on product modifications needed to match the new market, and develop a plan to market and distribute the product in this new business environment. In this…

Quantitative Methods for Determining U.S. Air Force Crew Cushion Comfort

DTIC Science & Technology

2006-09-01

Directorate Biosciences and Protection Division Biomechanics Branch Wright Patterson AFB OH 45433-7947 Form Approved REPORT DOCUMENTATION PAGE OMB No...Division Biomechanics Branch Wright-Patterson AFB OH 45433-7947 9. SPONSORING I MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S...workstations were constructed utilizing ejection seat long-term flight. mockups and foot pedal assemblies modified to simulate the ACES II seat in the F-16

Rolling Friction on a Wheeled Laboratory Cart

DTIC Science & Technology

2012-01-01

by gravity, and a vehicle (such as a car or bicycle) accelerating along a level road is driven by a motor or by pedalling. In such cases, static...is slowing down, its acceleration a points downhill). The normal force N, frictional force f and axle torque four wheels. θ υ N a θ ω τ ƒ mg...friction force pointed backward (to translationally decelerate the object), then it would simultaneously rotationally accelerate the cylinder about its

Baseline tests of the Zagato Elcar electric passenger vehicle

NASA Technical Reports Server (NTRS)

Sargent, N. B.; Maslowski, E. A.; Slavick, R. J.; Soltis, R. F.

1977-01-01

The Elcar vehicle performance test results are presented. The Elcar Model 2000 is a two-passenger vehicle with a reinforced fiberglass body. It is powered by eight 12-volt batteries. The batteries are connected to the motor through an arrangement of contactors operated from a foot pedal in conjunction with a hand-operated switch. These contactors change the voltage applied to the 2-kilowatt motor. Acceleration tests, operating characteristics, and instrumentation are described.

20. VIEW OF CONSOLE IN NORTHWEST CORNER OF SLC3W CONTROL ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

20. VIEW OF CONSOLE IN NORTHWEST CORNER OF SLC-3W CONTROL ROOM. PANELS FROM LEFT TO RIGHT: OPERATIONS AND CHECKOUT (LABELED POWER CONTROL AND MONITOR PANEL); RANGE SAFETY (LABELED DESTRUCT SYSTEM CONTROL AND MONITOR PANEL); BATTERY CLOCK PANELS. PEDAL FOR FOOT CONTROL OF COMMUNICATIONS HEADSET AND HEADSET IN FOREGROUND. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Operations Building, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

Magnetic resonance imaging of diabetic foot complications

PubMed Central

Low, Keynes TA; Peh, Wilfred CG

2015-01-01

This pictorial review aims to illustrate the various manifestations of the diabetic foot on magnetic resonance (MR) imaging. The utility of MR imaging and its imaging features in the diagnosis of pedal osteomyelitis are illustrated. There is often difficulty encountered in distinguishing osteomyelitis from neuroarthropathy, both clinically and on imaging. By providing an accurate diagnosis based on imaging, the radiologist plays a significant role in the management of patients with complications of diabetic foot. PMID:25640096

Study of Alternate Material for Pedal Ventilator Kits.

DTIC Science & Technology

1980-04-01

to fans with diameters of 36 inches or less, revealed that a shelter ventilation system of minimum cost would require three units with 36-inch...doorways, it was decided, with OCD approval, to develop pre-assembled one and two-operator bicycle ventilator kits utilizing a fan and ducting system of...polypropylene matrix. According to Ford Motor Company, an enthusiastic user, this material hybrid offers large potential savings in direct substitution for glass

Linear Modeling of Rotorcraft for Stability Analysis and Preliminary Design

DTIC Science & Technology

1993-09-01

Bmat ) disp(’ ’) disp(’press any key to continue...’) pause clc elseif choice==4, V...lateral cyclic, pedal.]’) diap(’ ’) diup ( Bmat ) disp(’ ’) disp(’ ’) diup(’ Higenvalue’) diup(’ ’) diap (’Uncoupled’) diup(’ ’) disp(’Longitudinal plant...containing matrix variables V Amat Bmat Rcoup Flataug Glataug Rlataug Plataug Flataug % Glataug Rlonaug Plonaug ’a V * Configuring variables

Loading, electromyograph, and motion during exercise

NASA Technical Reports Server (NTRS)

Figueroa, Fernando

1993-01-01

A system is being developed to gather kineto-dynamic data for a study to determine the load vectors applied to bone during exercise on equipment similar to that used in space. This information will quantify bone loading for exercise countermeasures development. Decreased muscle loading and external loading of bone during weightlessness results in cancellous bone loss of 1 percent per month in the lower extremities and 2 percent per month in the calcaneous. It is hypothesized that loading bone appropriately during exercise may prevent the bone loss. The system consists of an ergometer instrumented to provide position of the pedal (foot), pedaling forces on the foot (on the sagittal plane), and force on the seat. Accelerometers attached to the limbs will provide acceleration. These data will be used as input to an analytical model of the limb to determine forces on the bones and on groups of muscles. EMG signals from activity in the muscles will also be used in conjunction with the equations of mechanics of motion to be able to discern forces exerted by specific muscles. The tasks to be carried out include: design of various mechanical components to mount transducers, specification of mechanical components, specification of position transducers, development of a scheme to control the data acquisition instruments (TEAC recorder and optical encoder board), development of a dynamic model of the limbs in motion, and development of an overall scheme for data collection analysis and presentation. At the present time, all the hardware components of the system are operational, except for a computer board to gather position data from the pedals and crank. This board, however, may be put to use by anyone with background in computer based instrumentation. The software components are not all done. Software to transfer data recorded from the EMG measurements is operational, software to drive the optical encoder card is mostly done. The equations to model the kinematics and dynamics of motion of the limbs have been developed, but they have not yet been implemented in software. Aside from the development of the hardware and software components of the system, the methodology to use accelerometers and encoders and the formulation of the appropriate equations are an important contribution to the area of biomechanics, particularly in space applications.

Non-driving intersegmental knee moments in cycling computed using a model that includes three-dimensional kinematics of the shank/foot and the effect of simplifying assumptions.

PubMed

Gregersen, Colin S; Hull, M L

2003-06-01

Assessing the importance of non-driving intersegmental knee moments (i.e. varus/valgus and internal/external axial moments) on over-use knee injuries in cycling requires the use of a three-dimensional (3-D) model to compute these loads. The objectives of this study were: (1) to develop a complete, 3-D model of the lower limb to calculate the 3-D knee loads during pedaling for a sample of the competitive cycling population, and (2) to examine the effects of simplifying assumptions on the calculations of the non-driving knee moments. The non-driving knee moments were computed using a complete 3-D model that allowed three rotational degrees of freedom at the knee joint, included the 3-D inertial loads of the shank/foot, and computed knee loads in a shank-fixed coordinate system. All input data, which included the 3-D segment kinematics and the six pedal load components, were collected from the right limb of 15 competitive cyclists while pedaling at 225 W and 90 rpm. On average, the peak varus and internal axial moments of 7.8 and 1.5 N m respectively occurred during the power stroke whereas the peak valgus and external axial moments of 8.1 and 2.5 N m respectively occurred during the recovery stroke. However, the non-driving knee moments were highly variable between subjects; the coefficients of variability in the peak values ranged from 38.7% to 72.6%. When it was assumed that the inertial loads of the shank/foot for motion out of the sagittal plane were zero, the root-mean-squared difference (RMSD) in the non-driving knee moments relative to those for the complete model was 12% of the peak varus/valgus moment and 25% of the peak axial moment. When it was also assumed that the knee joint was revolute with the flexion/extension axis perpendicular to the sagittal plane, the RMSD increased to 24% of the peak varus/valgus moment and 204% of the peak axial moment. Thus, the 3-D orientation of the shank segment has a major affect on the computation of the non-driving knee moments, while the inertial contributions to these loads for motions out of the sagittal plane are less important.

Evaluation of Military Fuels Using a Ford 6.7L Powerstroke Diesel Engine

DTIC Science & Technology

2011-08-01

natural steady state values during idle testing steps. Engine oil cooler plumbing was factory integrated to the engine water jacket, thus not...Innospec Fuel Specialties DCI-4A. Per QPL-25017, the minimum effective treat rate of DCI-4A required an additive concentration level of 9ppm in the...dynamometer was used to control engine speed and dissipate load. Engine load was manipulated through the actuation of the engine throttle pedal assembly

Engineering Design Test 4 YAH-64 Advanced Attack Helicopter

DTIC Science & Technology

1980-01-01

representative absorber installed data. However, this data was used for comparison with the absorber removed vibration levels. Additionally, a comparison of the...Figure 5 presents a comparison of performance measured duriag EDT-4 and EDT-2. Dimensional data for each flight are presented in figures 6 through 9...pilot could easily compensate for the lack of yaw rate danilpilg. 28. The YAH-64 requires a high brake pedal pres,,ure dirw ! r )wtJ i.iv (pcrations and

An Analysis of Thrust Normalization of Ground Flowfield Pressures, Temperatures, and Velocities, for an AV-8B -408 Harrier During Hover

NASA Technical Reports Server (NTRS)

Naumowicz, Tim; Hange, Craig; Olson, Lawrence E. (Technical Monitor)

1998-01-01

An external environment test for an AV-8B Harrier during hover and vertical operations was conducted at NAWCAD at Patuxent River, Maryland in July 1997. Four boundary layer rakes were instrumented with static and total pressures, and thermocouples for measuring temperatures. These rakes were installed at 30, 50, 75, and 100 foot from the hover center. The 50 ft and 100 ft rakes were offset 20 deg from the other two to minimize interference effects. In order to measure a complete flowfield footprint, it was necessary to have the Harrier change its heading relative to the rakes from 0 to 180 deg. A 20 deg increment in azimuth was used. This permitted the four rakes to measure the flowfield at 72 locations relative to the aircraft. However, as the Harrier burns fuel, the hover thrust must be reduced by the pilot in order to maintain a constant height above ground. The typical test procedure employed was: (1) vertical takeoff at an initial heading; (2) 20 second hover dwell at that heading; (3) pedal turn to a second heading, followed by a 20 second dwell hover; (4) pedal turn to a third heading, followed by a 20 second dwell hover; and (5) vertical landing at the third heading. Additional information is contained in the original extended abstract.

Control of constraint forces and trajectories in a rich sensory and actuation environment.

PubMed

Hemami, Hooshang; Dariush, Behzad

2010-12-01

A simple control strategy is proposed and applied to a class of non-linear systems that have abundant sensory and actuation channels as in living systems. The main objective is the independent control of constrained trajectories of motion, and control of the corresponding constraint forces. The peripheral controller is a proportional, derivative and integral (PID) controller. A central controller produces, via pattern generators, reference signals that are the desired constrained position and velocity trajectories, and the desired constraint forces. The basic tenet of the this hybrid control strategy is the use of two mechanisms: 1. linear state and force feedback, and 2. non-linear constraint velocity feedback - sliding mode feedback. The first mechanism can be envisioned as a high gain feedback systems. The high gain attribute imitates the agonist-antagonist co-activation in natural systems. The strategy is applied to the control of the force and trajectory of a two-segment thigh-leg planar biped leg with a mass-less foot cranking a pedal that is analogous to a bicycle pedal. Five computational experiments are presented to show the effectiveness of the strategy and the performance of the controller. The findings of this paper are applicable to the design of orthoses and prostheses to supplement functional electrical stimulation for support purposes in the spinally injured cases. Copyright © 2010 Elsevier Inc. All rights reserved.

Functional pedal construct achieved by combined operative treatment in peritalar complex Charcot arthropathy: A prospective study of 38 feet.

PubMed

El-Mowafi, Hani; El-Hawary, Ahmed; Kandil, Yasser

2017-03-06

Charcot arthropathy of the peritalar complex carries a high risk of amputation if not properly managed. Our aim is to assess the functional outcome of severe Charcot arthropathy of the peritalar complex following enblock resection of the ulcer, massive debridement and stabilizing all the elements of the peritalar complex. We prospectively studied 38 feet in 35 patients with peritalar complex Charcot arthropathy. All Feet underwent intense debridement and fusion using a combination of (Ilizarov) external fixation, and (plate and locked nail) internal fixation. Thirty two feet were graded as Eichenholtz 2, and six feet were graded as Eichenholtz 3. The mean follow up was 35.9months. The mean AOFAS score was significantly elevated from 25.4±9.1 preoperatively to 67.6±5.7 at the most recent follow-up (p<0.001). Complete bony fusion was achieved in 28 feet. Unsound bony fusion occurred in 8 feet. Two feet required below knee amputation. Peritalar complex Charcot arthropathy is not uncommon variety. Such cases carry high risk of complications and amputation is not excluded. The proper timing of surgery is crucial. Massive debridement and rigid fixation with strict follow up is mandatory to achieve the ultimate goal of obtaining a plantigrade, stable, mechanically sound, painless and infection free pedal construct. Copyright © 2017 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

Changes in cortical activity measured with EEG during a high-intensity cycling exercise

PubMed Central

Cortese, Filomeno; Maurer, Christian; Baltich, Jennifer; Protzner, Andrea B.; Nigg, Benno M.

2015-01-01

This study investigated the effects of a high-intensity cycling exercise on changes in spectral and temporal aspects of electroencephalography (EEG) measured from 10 experienced cyclists. Cyclists performed a maximum aerobic power test on the first testing day followed by a time-to-exhaustion trial at 85% of their maximum power output on 2 subsequent days that were separated by ∼48 h. EEG was recorded using a 64-channel system at 500 Hz. Independent component (IC) analysis parsed the EEG scalp data into maximal ICs. An equivalent current dipole model was calculated for each IC, and results were clustered across subjects. A time-frequency analysis of the identified electrocortical clusters was performed to investigate the magnitude and timing of event-related spectral perturbations. Significant changes (P < 0.05) in electrocortical activity were found in frontal, supplementary motor and parietal areas of the cortex. Overall, there was a significant increase in EEG power as fatigue developed throughout the exercise. The strongest increase was found in the frontal area of the cortex. The timing of event-related desynchronization within the supplementary motor area corresponds with the onset of force production and the transition from flexion to extension in the pedaling cycle. The results indicate an involvement of the cerebral cortex during the pedaling task that most likely involves executive control function, as well as motor planning and execution. PMID:26538604

Chest ultrasound and hidden lung congestion in peritoneal dialysis patients.

PubMed

Panuccio, Vincenzo; Enia, Giuseppe; Tripepi, Rocco; Torino, Claudia; Garozzo, Maurizio; Battaglia, Giovanni Giorgio; Marcantoni, Carmelita; Infantone, Lorena; Giordano, Guido; De Giorgi, Maria Loreta; Lupia, Mario; Bruzzese, Vincenzo; Zoccali, Carmine

2012-09-01

Chest ultrasound (US) is a non-invasive well-validated technique for estimating extravascular lung water (LW) in patients with heart diseases and in end-stage renal disease. We systematically applied this technique to the whole peritoneal dialysis (PD) population of five dialysis units. We studied the cross-sectional association between LW, echocardiographic parameters, clinical [pedal oedema, New York Heart Association (NYHA) class] and bioelectrical impedance analysis (BIA) markers of volume status in 88 PD patients. Moderate to severe lung congestion was evident in 41 (46%) patients. Ejection fraction was the echocardiographic parameter with the strongest independent association with LW (r = -0.40 P = 0.002). Oedema did not associate with LW on univariate and multivariate analysis. NYHA class was slightly associated with LW (r = 0.21 P = 0.05). Among patients with severe lung congestion, only 27% had pedal oedema and the majority (57%) had no dyspnoea (NYHA Class I). Similarly, the prevalence of patients with BIA, evidence of volume excess was small (11%) and not significantly different (P = 0.79) from that observed in patients with mild or no congestion (9%). In PD patients, LW by chest US reveals moderate to severe lung congestion in a significant proportion of asymptomatic patients. Intervention studies are necessary to prove the usefulness of chest US for optimizing the control of fluid excess in PD patients.

Sexual Plasticity and Self-Fertilization in the Sea Anemone Aiptasia diaphana

PubMed Central

Schlesinger, Ami; Kramarsky-Winter, Esti; Rosenfeld, Hanna; Armoza-Zvoloni, Rachel; Loya, Yossi

2010-01-01

Traits that influence reproductive success and contribute to reproductive isolation in animal and plant populations are a central focus of evolutionary biology. In the present study we used an experimental approach to demonstrate the occurrence of environmental effects on sexual and asexual reproduction, and provide evidence for sexual plasticity and inter-clonal fertilization in laboratory-cultured lines of the sea anemone Aiptasia diaphana. We showed that in A. diaphana, both asexual reproduction by pedal laceration, and sexual reproduction have seasonal components. The rate of pedal laceration was ten-fold higher under summer photoperiod and water temperature conditions than under winter conditions. The onset of gametogenesis coincided with the rising water temperatures occurring in spring, and spawning occurred under parameters that emulated summer photoperiod and temperature conditions. In addition, we showed that under laboratory conditions, asexually produced clones derived from a single founder individual exhibit sexual plasticity, resulting in the development of both male and female individuals. Moreover, a single female founder produced not only males and females but also hermaphrodite individuals. We further demonstrated that A. diaphana can fertilize within and between clone lines, producing swimming planula larvae. These diverse reproductive strategies may explain the species success as invader of artificial marine substrates. We suggest that these diverse reproductive strategies, together with their unique evolutionary position, make Aiptasia diaphana an excellent model for studying the evolution of sex. PMID:20686700

Experimental study for the reproduction of sudden unintended acceleration incidents.

PubMed

Park, Sungji; Choi, Youngsuk; Choi, Woongchul

2016-10-01

A few cases of the sudden unintended acceleration have been reported over the last few years [1-11] and some of them seemed to be somewhat related to an electronic throttle control (ETC) system [11,12]. In this experimental study, efforts were made to reproduce the cases of sudden unintended acceleration possibly related to the ETC. Typically, an ETC of the engine is managed based on signals from airflow sensor, throttle position sensor and acceleration pedal sensor. With this typical sensor configuration in mind, these sensor signals were checked for noise levels. However, none of them showed any clear relationship with the sudden unintended acceleration mainly due to the robustness of the ETC logic software. As an alternative approach, supply voltage to an engine control unit (ECU) was tempered intentionally to observe any clues for the incidents. The observed results with the supply voltage drop and fluctuation tests were rather astonishing. The throttle valve position went all the way up to 100% for around one second when the battery voltage plunged down to 7V periodically despite that the acceleration pedal position was kept steady. As an effort to confirm the case, multiple tries were made systematically on a chassis dynamometer as well as on the test road. In this paper, detailed procedures and findings are reported accordingly. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Dynamic locomotor capabilities revealed by early dinosaur trackmakers from southern Africa.

PubMed

Wilson, Jeffrey A; Marsicano, Claudia A; Smith, Roger M H

2009-10-06

A new investigation of the sedimentology and ichnology of the Early Jurassic Moyeni tracksite in Lesotho, southern Africa has yielded new insights into the behavior and locomotor dynamics of early dinosaurs. The tracksite is an ancient point bar preserving a heterogeneous substrate of varied consistency and inclination that includes a ripple-marked riverbed, a bar slope, and a stable algal-matted bar top surface. Several basal ornithischian dinosaurs and a single theropod dinosaur crossed its surface within days or perhaps weeks of one another, but responded to substrate heterogeneity differently. Whereas the theropod trackmaker accommodated sloping and slippery surfaces by gripping the substrate with its pedal claws, the basal ornithischian trackmakers adjusted to the terrain by changing between quadrupedal and bipedal stance, wide and narrow gauge limb support (abduction range = 31 degrees ), and plantigrade and digitigrade foot posture. The locomotor adjustments coincide with changes in substrate consistency along the trackway and appear to reflect 'real time' responses to a complex terrain. It is proposed that these responses foreshadow important locomotor transformations characterizing the later evolution of the two main dinosaur lineages. Ornithischians, which shifted from bipedal to quadrupedal posture at least three times in their evolutionary history, are shown to have been capable of adopting both postures early in their evolutionary history. The substrate-gripping behavior demonstrated by the early theropod, in turn, is consistent with the hypothesized function of pedal claws in bird ancestors.

Design and Development of a Smart Exercise Bike for Motor Rehabilitation in Individuals with Parkinson’s Disease

PubMed Central

Mohammadi-Abdar, Hassan; Ridgel, Angela L.; Discenzo, Fred M.; Loparo, Kenneth A.

2016-01-01

Recent studies in rehabilitation of Parkinson’s disease (PD) have shown that cycling on a tandem bike at a high pedaling rate can reduce the symptoms of the disease. In this research, a smart motorized bicycle has been designed and built for assisting Parkinson’s patients with exercise to improve motor function. The exercise bike can accurately control the rider’s experience at an accelerated pedaling rate while capturing real-time test data. Here, the design and development of the electronics and hardware as well as the software and control algorithms are presented. Two control algorithms have been developed for the bike; one that implements an inertia load (static mode) and one that implements a speed reference (dynamic mode). In static mode the bike operates as a regular exercise bike with programmable resistance (load) that captures and records the required signals such as heart rate, cadence and power. In dynamic mode the bike operates at a user-selected speed (cadence) with programmable variability in speed that has been shown to be essential to achieving the desired motor performance benefits for PD patients. In addition, the flexible and extensible design of the bike permits readily changing the control algorithm and incorporating additional I/O as needed to provide a wide range of riding experiences. Furthermore, the network-enabled controller provides remote access to bike data during a riding session. PMID:27298575

Influence of Knee Joint Extension on Submaximal Oxygen Consumption and Anaerobic Power in Cyclists

DTIC Science & Technology

1991-06-05

Cycling (pp. 91-122). Champaign, IL: Human Kinetics Books. Cavanagh, P.R. & Kram, R. (1985). Mechanical and muscular factors affecting the efficiency...M.L. (1986). Flexibility standards of the U.S. cycling team. In E.R. Burke (Ed.). Science of Cycling (pp. 47-68). Champaign, IL: Human Kinetics Books...height and pedaling cadence on power output and efficiency. In E.R. Burke (Ed.). Science of Cycling (pp. 69-907). Champaign, IL: Human Kinetics Books

Electromyographic Analysis of the Peroneous Longus during Bicycle Ergometry across Work Load and Pedal Type.

DTIC Science & Technology

1983-01-01

adjusted for each subject to 60 cycles per minute using a metronome. Gait cycle was determined using an electrical pressure switch attached to the...dental burr. Electrodes were filled with conducting gel and held in place with double adhesive rings. An electrical pressure switch was taped to the...the pressure switch was carried on a separate wire to the recording equipment. All wires were held tightly against the subject’s leg to reduce

A Review of the Anthropometric and Strength Standards of the Canadian Motor Vehicle Safety Standard,

DTIC Science & Technology

1980-02-01

to manipulate them to fit a0 3 particular design. For example, the designer is required to be familiar with certain biomechanical properties of the...see Ref. 11 for example). What is probably required is the dynamic anthropometry approach used by Ely et al. (Ref. 10) to determine the overall pedal ... biomechanical model, COMBIMAN (Ref. 13) has universal application because the basic parameters of the model can be altered to represent any desired

Wheelchair ergometer. Development of a prototype with electronic braking.

PubMed

Forchheimer, F; Lundberg, A

1986-01-01

A new wheelchair ergometer is described, which compensates for the pulsating character of the work by an automatic control system. This makes it possible to maintain a constant level of power during wheelchair work. An automatic control system has been integrated in an electronically braked bicycle ergometer, and a pedal unit from Rodby Electronic bicycle ergometer RE 820 has been coupled to a modified test wheelchair. With this device, the physical working capacity during submaximal circumstances can be tested in handicapped persons.

Wind-Tunnel Tests of the 1/9-Scale Model of the Curtiss XP-62 Airplane with Various Vertical Tail Arrangements

NASA Technical Reports Server (NTRS)

Wallace, Arthur R.; Recant, I.G.

1943-01-01

The effect of various vertical tail arrangements upon the stability and control characteristics of an XP-62 fighter model was investigated. Rudder-free yaw characteristics with take-off power and flaps deflected were satisfactory after dorsal fin modifications. Directional stability was obtained with all modified vertical tails. Satisfactory rudder effectiveness resulted partly because the dual-rotation propellers produced no asymmetric yawing moments. Pedal forces in sideslips were undesirably large but may be easily reduced.

Erythrocyte volume in acidified venous blood from exercising limbs.

NASA Technical Reports Server (NTRS)

Van Beaumont, W.; Rochelle, R. H.

1973-01-01

Five male volunteers performed arm exercises in the sitting position by cranking the pedals of a bicycle ergometer at 50 revolutions per min. The initial mechanical work load of 0 kgm/min was increased every minute by 75 kgm/min until exhaustion occurred. The data obtained show a significant acidification of the venous blood from the working arms and a substantial increase in venous pCO2 during this type of muscular activity. However, the erythrocyte volume remained unaltered during the exercise.

Pedal macrodactyly: coverage of a large defect with a rectus abdominus free flap.

PubMed

Hendrix, C L; Thomson, J G; Blume, P A

2000-01-01

The authors report a case of a unique reconstructive approach for an isolated macrodactyly of the lower extremity in an otherwise healthy African male. Surgical treatment included excision and local resection of the affected hypertrophied skin, soft tissue, and bone. A rectus abdominis free-tissue transfer and split-thickness skin graft were used for coverage of the defect. The foot healed without complication, and at 2-year follow-up, the patient had an aesthetically pleasing and fully functional result.

Flightfax - Army Aviation Risk-Management Information. Volume 25, Number 11, August 1997. Snow

DTIC Science & Technology

1997-08-01

but why haven’t Loach that would ensure our surviving a multiple- you been acknowledging the radio calls?" A quick wire strike. check confirmed that...helicopter upright with only the collective and Loach on post with skid shoes, the skid cleats would pedals. have snagged the middle wire and flipped...is more cost effective to overhaul until because masking violated FAA Mr. Ken Muzzo, DSN 490-2257 (314-260- the retirement life is reached. The

Commercial-off-the-Shelf Vehicles for Towed Array Magnetometry

DTIC Science & Technology

2009-09-01

dump bed on the back, has upright seating for two adults, has the seats oriented side-by-side, and has a steering wheel and brake and accelerator... pedals like a car. By way of example, a ubiquitous side-by-side UTV is the John Deere Gator. The objective of this project was to test a number of...different angle , and one set of biases will not be able to take out all of the streaks. This raises the second issue. Because the bidirectional

Commercial-Off-The-Shelf Vehicles for Towed Array Magnetometry

DTIC Science & Technology

2009-09-01

a steering wheel, and brake and accelerator pedals like a car. By way of example, a ubiquitous side-by- side UTV is the John Deere Gator. The...tire tracks are imperfectly 42 followed. These new tracks will be at a slightly different angle , and one set of biases will not be able to take...tracks at an angle relative to the north-south traverses that we ran. In addition, we surveyed into the muddy wet section at the western end of the site

Design Loads for Future Aircraft (Les Charges de Calcul Pour de Futurs Aeronefs)

DTIC Science & Technology

2002-02-01

brake attachment bolt you first have to remove both ejection seats and the actuator cover that is located between the right position rudder pedals . Since...continuous turbulence and inclusion of FCS failure cases and nonlinearities such as control surface angles is extremely important. There was a long way...FCS) et des non-linéarités, tels que les angles de gouverne, sont extrêmement importantes. Un long chemin sépare les hypothèses de charge

Baseline tests of the EVA contractor electric passenger vehicle

NASA Technical Reports Server (NTRS)

Bozek, J. M.; Tryon, H. B.; Slavick, R. J.

1977-01-01

The EVA Contactor four door sedan, an electric passenger vehicle, was tested to characterize the state-of-the-art of electric vehicles. It is a four passenger sedan that was converted to an electric vehicle. It is powered by 16 series connected 6 volt electric vehicle batteries through a four step contactor controller actuated by a foot accelerator pedal. The controller changes the voltage applied to the separately excited DC motor. The braking system is a vacuum assisted hydraulic braking system. Regenerative braking was also provided.

Developing a Knowledge Base for Detection of Powertrain Failures by Reversibly Seeding Engine Faults

DTIC Science & Technology

2010-08-01

output, in terms of torque, speed and heat losses, can be accurately performed. Our investigation has focused on creating faulty operating conditions...open loop case”, used to measure the engine output for a given driver demand, for instance, 100% pedal); in the other case (“ closed loop ”) engine...could be changed in nine steps ranging from completely open to fully closed . Another butterfly valve was placed at the end of the exhaust pipe before

The incidence of tinea pedis in diabetic versus nondiabetic patients with interdigital macerations: a prospective study.

PubMed

Legge, Bradford S; Grady, John F; Lacey, Autum M

2008-01-01

We sought to determine the incidence of tinea pedis in patients with otherwise asymptomatic pedal interdigital macerations. Both diabetic and nondiabetic populations were compared. Age and body mass index were also examined for their significance. Fungal cultures of skin scrapings from 80 patients (77 male and 3 female; mean age, 65 years) with interdigital macerations were performed; 40 patients had previously been diagnosed with type 2 diabetes and 40 did not have diabetes. Cultures revealed a 40% prevalence of tinea pedis in the total study population. The prevalence in the nondiabetic group was 37.5% and 42.5% for the diabetic group. This was not a statistically significant difference. Among patients with interdigital macerations that yielded positive fungal cultures, those in the nondiabetic group were 6.3 years older than those in the diabetic group. It was also observed that the nondiabetic patients with interdigital macerations yielding positive fungal cultures were 9.1 years older than patients with negative fungal cultures in the nondiabetic group. The results of this study provide the practitioner with a guide for treating pedal interdigital macerations. Because the likelihood of a tinea pedis infection is 40%, it seems prudent to treat these macerations with an antifungal agent. In regard to age, the results suggest that as nondiabetic patients age, the likelihood of an otherwise asymptomatic interdigital maceration yielding a positive fungal culture increases, and that diabetic patients may be susceptible to interdigital fungal infections at a younger age than those without diabetes.

Muscle coordination in cycling: effect of surface incline and posture.

PubMed

Li, L; Caldwell, G E

1998-09-01

The purpose of the present study was to examine the neuromuscular modifications of cyclists to changes in grade and posture. Eight subjects were tested on a computerized ergometer under three conditions with the same work rate (250 W): pedaling on the level while seated, 8% uphill while seated, and 8% uphill while standing (ST). High-speed video was taken in conjunction with surface electromyography (EMG) of six lower extremity muscles. Results showed that rectus femoris, gluteus maximus (GM), and tibialis anterior had greater EMG magnitude in the ST condition. GM, rectus femoris, and the vastus lateralis demonstrated activity over a greater portion of the crank cycle in the ST condition. The muscle activities of gastrocnemius and biceps femoris did not exhibit profound differences among conditions. Overall, the change of cycling grade alone from 0 to 8% did not induce a significant change in neuromuscular coordination. However, the postural change from seated to ST pedaling at 8% uphill grade was accompanied by increased and/or prolonged muscle activity of hip and knee extensors. The observed EMG activity patterns were discussed with respect to lower extremity joint moments. Monoarticular extensor muscles (GM, vastus lateralis) demonstrated greater modifications in activity patterns with the change in posture compared with their biarticular counterparts. Furthermore, muscle coordination among antagonist pairs of mono- and biarticular muscles was altered in the ST condition; this finding provides support for the notion that muscles within these antagonist pairs have different functions.

Pedaling rate is an important determinant of human oxygen uptake during exercise on the cycle ergometer

PubMed Central

Formenti, Federico; Minetti, Alberto E; Borrani, Fabio

2015-01-01

Estimation of human oxygen uptake () during exercise is often used as an alternative when its direct measurement is not feasible. The American College of Sports Medicine (ACSM) suggests estimating human during exercise on a cycle ergometer through an equation that considers individual's body mass and external work rate, but not pedaling rate (PR). We hypothesized that including PR in the ACSM equation would improve its prediction accuracy. Ten healthy male participants’ (age 19–48 years) were recruited and their steady-state was recorded on a cycle ergometer for 16 combinations of external work rates (0, 50, 100, and 150 W) and PR (50, 70, 90, and 110 revolutions per minute). was calculated by means of a new equation, and by the ACSM equation for comparison. Kinematic data were collected by means of an infrared 3-D motion analysis system in order to explore the mechanical determinants of . Including PR in the ACSM equation improved the accuracy for prediction of sub-maximal during exercise (mean bias 1.9 vs. 3.3 mL O2 kg−1 min−1) but it did not affect the accuracy for prediction of maximal (P > 0.05). Confirming the validity of this new equation, the results were replicated for data reported in the literature in 51 participants. We conclude that PR is an important determinant of human during cycling exercise, and it should be considered when predicting oxygen consumption. PMID:26371230

Target innervation is necessary for neuronal polyploidization in the terrestrial slug Limax.

PubMed

Matsuo, Ryota; Yamagishi, Miki; Wakiya, Kyoko; Tanaka, Yoko; Ito, Etsuro

2013-08-01

The brain of gastropod mollusks contains many giant neurons with polyploid genomic DNAs. Such DNAs are generated through repeated DNA endoreplication during body growth. However, it is not known what triggers DNA endoreplication in neurons. There are two possibilities: (1) DNAs are replicated in response to some unknown molecules in the hemolymph that reflect the nutritive status of the animal; or (2) DNAs are replicated in response to some unknown factors that are retrogradely transported through axons from the innervated target organs. We first tested whether hemolymph with rich nutrition could induce DNA endoreplication. We tested whether the transplanted brain exhibits enhanced DNA endoreplication like an endogenous brain does when transplanted into the homocoel of the body of a slug whose body growth is promoted by an increased food supply. However, no enhancement was observed in the frequency of DNA endoreplication when we compared the transplanted brains in the growth-promoted and growth-suppressed host slugs, suggesting that the humoral environment is irrelevant to triggering the body growth-dependent DNA endoreplication. Next, we tested the requirement of target innervation by surgically dissecting a unilateral posterior pedal nerve of an endogenous brain. Substantially lower number of neurons exhibited DNA endoreplication in the pedal ganglion ipsilateral to the dissected nerve. These results support the view that enhanced DNA endoreplication is mediated by target innervation and is not brought about through the direct effect of humoral factors in the hemolymph during body growth. Copyright © 2013 Wiley Periodicals, Inc.

A low-cost Mr compatible ergometer to assess post-exercise phosphocreatine recovery kinetics.

PubMed

Naimon, Niels D; Walczyk, Jerzy; Babb, James S; Khegai, Oleksandr; Che, Xuejiao; Alon, Leeor; Regatte, Ravinder R; Brown, Ryan; Parasoglou, Prodromos

2017-06-01

To develop a low-cost pedal ergometer compatible with ultrahigh (7 T) field MR systems to reliably quantify metabolic parameters in human lower leg muscle using phosphorus magnetic resonance spectroscopy. We constructed an MR compatible ergometer using commercially available materials and elastic bands that provide resistance to movement. We recruited ten healthy subjects (eight men and two women, mean age ± standard deviation: 32.8 ± 6.0 years, BMI: 24.1 ± 3.9 kg/m 2 ). All subjects were scanned on a 7 T whole-body magnet. Each subject was scanned on two visits and performed a 90 s plantar flexion exercise at 40% maximum voluntary contraction during each scan. During the first visit, each subject performed the exercise twice in order for us to estimate the intra-exam repeatability, and once during the second visit in order to estimate the inter-exam repeatability of the time constant of phosphocreatine recovery kinetics. We assessed the intra and inter-exam reliability in terms of the within-subject coefficient of variation (CV). We acquired reliable measurements of PCr recovery kinetics with an intra- and inter-exam CV of 7.9% and 5.7%, respectively. We constructed a low-cost pedal ergometer compatible with ultrahigh (7 T) field MR systems, which allowed us to quantify reliably PCr recovery kinetics in lower leg muscle using 31 P-MRS.

Solid-state one-way photoisomerisation of Z,E,Z-1,6-(4,4'-diphenyl)hexa-1,3,5-triene dicarboxylate examined using higher-order derivative spectra and powder XRD patterns.

PubMed

Sonoda, Yoriko; Goto, Midori; Ichimura, Kunihiro

2018-03-14

Higher order derivative spectra were applied at first to one-way ZEZ-to-EEE photoisomerisation of dimethyl ester (ZEZ-DPH1) of the titled compound in a methylcyclohexane solution. Many common crossing points emerged in UV-induced derivative-spectral changes to reveal the direct ZEZ-to-EEE photoisomerisation without the transient formation of an intermediate to suggest the bicycle-pedal mechanism. The solid-state photoisomerisation was subsequently monitored by tracing changes in the fourth-order derivatives of absorption spectra of a thin crystalline layer of ZEZ-DPH1 prepared by the drop-casting method, because the distortion of absorption spectra due to light scattering is cancelled. It was suggested that the solid-state photochemical event consists of three steps: fast ZEZ-to-EEE photoisomerisation, a subsequent slow ZEZ-to-EEE photoisomerisation and very slow disappearance of the EEE-isomer. Studies on powder XRD were also carried out for a drop-cast solid layer of ZEZ-DPH1 to disclose the coexistence of a crystal form other than the original one, and the former exhibited faster ZEZ-to-EEE photoisomerisation when compared with the original crystal form. The results revealed by XRD analysis are in line with those obtained by higher-order derivative spectra, confirming the solid-state one-way photoisomerisation to take place through the bicycle-pedal process.

Walking, running and the evolution of short toes in humans.

PubMed

Rolian, Campbell; Lieberman, Daniel E; Hamill, Joseph; Scott, John W; Werbel, William

2009-03-01

The phalangeal portion of the forefoot is extremely short relative to body mass in humans. This derived pedal proportion is thought to have evolved in the context of committed bipedalism, but the benefits of shorter toes for walking and/or running have not been tested previously. Here, we propose a biomechanical model of toe function in bipedal locomotion that suggests that shorter pedal phalanges improve locomotor performance by decreasing digital flexor force production and mechanical work, which might ultimately reduce the metabolic cost of flexor force production during bipedal locomotion. We tested this model using kinematic, force and plantar pressure data collected from a human sample representing normal variation in toe length (N=25). The effect of toe length on peak digital flexor forces, impulses and work outputs was evaluated during barefoot walking and running using partial correlations and multiple regression analysis, controlling for the effects of body mass, whole-foot and phalangeal contact times and toe-out angle. Our results suggest that there is no significant increase in digital flexor output associated with longer toes in walking. In running, however, multiple regression analyses based on the sample suggest that increasing average relative toe length by as little as 20% doubles peak digital flexor impulses and mechanical work, probably also increasing the metabolic cost of generating these forces. The increased mechanical cost associated with long toes in running suggests that modern human forefoot proportions might have been selected for in the context of the evolution of endurance running.

Diffuse optical characterization of an exercising patient group with peripheral artery disease

PubMed Central

Putt, Mary; Chandra, Malavika; Yu, Guoqiang; Xing, Xiaoman; Han, Sung Wan; Lech, Gwen; Shang, Yu; Durduran, Turgut; Zhou, Chao; Yodh, Arjun G.; Mohler, Emile R.

2013-01-01

Abstract. Peripheral artery disease (PAD) is a common condition with high morbidity. While measurement of tissue oxygen saturation (StO2) has been demonstrated, this is the first study to assess both StO2 and relative blood flow (rBF) in the extremities of PAD patients. Diffuse optics is employed to measure hemodynamic response to treadmill and pedal exercises in 31 healthy controls and 26 patients. For StO2, mild and moderate/severe PAD groups show pronounced differences compared with controls. Pre-exercise mean StO2 is lower in PAD groups by 9.3% to 10.6% compared with means of 63.5% to 66.2% in controls. For pedal, relative rate of return of StO2 to baseline is more rapid in controls (p<0.05). Patterns of rBF also differ among groups. After both exercises, rBF tend to occur at depressed levels among severe PAD patients compared with healthy (p<0.05); post-treadmill, rBF tend to occur at elevated levels among healthy compared with severe PAD patients (p<0.05). Additionally, relative rate of return to baseline StO2 is more rapid among subjects with reduced levels of depression in rBF (p=0.041), even after adjustment for ankle brachial index. This suggests a physiologic connection between rBF and oxygenation that can be measured using diffuse optics, and potentially employed as an evaluative tool in further studies. PMID:23708193

In dubio pro silentio - Even Loud Music Does Not Facilitate Strenuous Ergometer Exercise.

PubMed

Kreutz, Gunter; Schorer, Jörg; Sojke, Dominik; Neugebauer, Judith; Bullack, Antje

2018-01-01

Background: Music listening is wide-spread in amateur sports. Ergometer exercise is one such activity which is often performed with loud music. Aim and Hypotheses: We investigated the effects of electronic music at different intensity levels on ergometer performance (physical performance, force on the pedal, pedaling frequency), perceived fatigue and heart rate in healthy adults. We assumed that higher sound intensity levels are associated with greater ergometer performance and less perceived effort, particularly for untrained individuals. Methods: Groups of high trained and low trained healthy males ( N = 40; age = 25.25 years; SD = 3.89 years) were tested individually on an ergometer while electronic dance music was played at 0, 65, 75, and 85 dB. Participants assessed their music experience during the experiment. Results: Majorities of participants rated the music as not too loud (65%), motivating (77.50%), appropriate for this sports exercise (90%), and having the right tempo (67.50%). Participants noticed changes in the acoustical environment with increasing intensity levels, but no further effects on any of the physical or other subjective measures were found for neither of the groups. Therefore, the main hypothesis must be rejected. Discussion: These findings suggest that high loudness levels do not positively influence ergometer performance. The high acceptance of loud music and perceived appropriateness could be based on erroneous beliefs or stereotypes. Reasons for the widespread use of loud music in fitness sports needs further investigation. Reducing loudness during fitness exercise may not compromise physical performance or perceived effort.

Regenerative braking failures in battery electric vehicles and their impact on the driver.

PubMed

Cocron, Peter; Neumann, Isabel; Kreußlein, Maria; Wanner, Daniel; Bierbach, Maxim; Krems, Josef F

2018-09-01

A unique feature of battery electric vehicles (BEV) is their regenerative braking system (RBS) to recapture kinetic energy in deceleration maneuvers. If such a system is triggered via gas pedal, most deceleration maneuvers can be executed by just using this pedal. This impacts the driving task as different deceleration strategies can be applied. Previous research has indicated that a RBS failure leading to a sudden reduced deceleration represents an adverse event for BEV drivers. In the present study, we investigated such a failure's impact on the driver's evaluation and behavior. We conducted an experiment on a closed-off test track using a modified BEV that could temporarily switch off the RBS. One half of the 44 participants in the study received information about an upcoming RBS failure whereas the other half did not. While 91% of the drivers receiving prior information noticed the RBS failure, only 48% recognized it in the "uniformed" group. In general, the failure and the perception of its occurrence influenced the driver's evaluation and behavior more than receiving prior information. Nevertheless, under the tested conditions, drivers kept control and were able to compensate for the RBS failure. As the participants drove quite simple maneuvers in our experiment, further studies are needed to validate our findings using more complex driving settings. Given that RBS failures could have severe consequences, appropriate information and warning strategies for drivers are necessary. Copyright © 2018 Elsevier Ltd. All rights reserved.

Early Paleocene landbird supports rapid phylogenetic and morphological diversification of crown birds after the K-Pg mass extinction.

PubMed

Ksepka, Daniel T; Stidham, Thomas A; Williamson, Thomas E

2017-07-25

Evidence is accumulating for a rapid diversification of birds following the K-Pg extinction. Recent molecular divergence dating studies suggest that birds radiated explosively during the first few million years of the Paleocene; however, fossils from this interval remain poorly represented, hindering our understanding of morphological and ecological specialization in early neoavian birds. Here we report a small fossil bird from the Nacimiento Formation of New Mexico, constrained to 62.221-62.517 Ma. This partial skeleton represents the oldest arboreal crown group bird known. Phylogenetic analyses recovered Tsidiiyazhi abini gen. et sp. nov. as a member of the Sandcoleidae, an extinct basal clade of stem mousebirds (Coliiformes). The discovery of Tsidiiyazhi pushes the minimum divergence ages of as many as nine additional major neoavian lineages into the earliest Paleocene, compressing the duration of the proposed explosive post-K-Pg radiation of modern birds into a very narrow temporal window parallel to that suggested for placental mammals. Simultaneously, Tsidiiyazhi provides evidence for the rapid morphological (and likely ecological) diversification of crown birds. Features of the foot indicate semizygodactyly (the ability to facultatively reverse the fourth pedal digit), and the arcuate arrangement of the pedal trochleae bears a striking resemblance to the conformation in owls (Strigiformes). Inclusion of fossil taxa and branch length estimates impacts ancestral state reconstructions, revealing support for the independent evolution of semizygodactyly in Coliiformes, Leptosomiformes, and Strigiformes, none of which is closely related to extant clades exhibiting full zygodactyly.

Early Paleocene landbird supports rapid phylogenetic and morphological diversification of crown birds after the K-Pg mass extinction

NASA Astrophysics Data System (ADS)

Ksepka, Daniel T.; Stidham, Thomas A.; Williamson, Thomas E.

2017-07-01

Evidence is accumulating for a rapid diversification of birds following the K-Pg extinction. Recent molecular divergence dating studies suggest that birds radiated explosively during the first few million years of the Paleocene; however, fossils from this interval remain poorly represented, hindering our understanding of morphological and ecological specialization in early neoavian birds. Here we report a small fossil bird from the Nacimiento Formation of New Mexico, constrained to 62.221-62.517 Ma. This partial skeleton represents the oldest arboreal crown group bird known. Phylogenetic analyses recovered Tsidiiyazhi abini gen. et sp. nov. as a member of the Sandcoleidae, an extinct basal clade of stem mousebirds (Coliiformes). The discovery of Tsidiiyazhi pushes the minimum divergence ages of as many as nine additional major neoavian lineages into the earliest Paleocene, compressing the duration of the proposed explosive post-K-Pg radiation of modern birds into a very narrow temporal window parallel to that suggested for placental mammals. Simultaneously, Tsidiiyazhi provides evidence for the rapid morphological (and likely ecological) diversification of crown birds. Features of the foot indicate semizygodactyly (the ability to facultatively reverse the fourth pedal digit), and the arcuate arrangement of the pedal trochleae bears a striking resemblance to the conformation in owls (Strigiformes). Inclusion of fossil taxa and branch length estimates impacts ancestral state reconstructions, revealing support for the independent evolution of semizygodactyly in Coliiformes, Leptosomiformes, and Strigiformes, none of which is closely related to extant clades exhibiting full zygodactyly.

Early Paleocene landbird supports rapid phylogenetic and morphological diversification of crown birds after the K–Pg mass extinction

PubMed Central

Ksepka, Daniel T.; Stidham, Thomas A.; Williamson, Thomas E.

2017-01-01

Evidence is accumulating for a rapid diversification of birds following the K–Pg extinction. Recent molecular divergence dating studies suggest that birds radiated explosively during the first few million years of the Paleocene; however, fossils from this interval remain poorly represented, hindering our understanding of morphological and ecological specialization in early neoavian birds. Here we report a small fossil bird from the Nacimiento Formation of New Mexico, constrained to 62.221–62.517 Ma. This partial skeleton represents the oldest arboreal crown group bird known. Phylogenetic analyses recovered Tsidiiyazhi abini gen. et sp. nov. as a member of the Sandcoleidae, an extinct basal clade of stem mousebirds (Coliiformes). The discovery of Tsidiiyazhi pushes the minimum divergence ages of as many as nine additional major neoavian lineages into the earliest Paleocene, compressing the duration of the proposed explosive post–K–Pg radiation of modern birds into a very narrow temporal window parallel to that suggested for placental mammals. Simultaneously, Tsidiiyazhi provides evidence for the rapid morphological (and likely ecological) diversification of crown birds. Features of the foot indicate semizygodactyly (the ability to facultatively reverse the fourth pedal digit), and the arcuate arrangement of the pedal trochleae bears a striking resemblance to the conformation in owls (Strigiformes). Inclusion of fossil taxa and branch length estimates impacts ancestral state reconstructions, revealing support for the independent evolution of semizygodactyly in Coliiformes, Leptosomiformes, and Strigiformes, none of which is closely related to extant clades exhibiting full zygodactyly. PMID:28696285

Peripheral oxygen-sensing cells directly modulate the output of an identified respiratory central pattern generating neuron.

PubMed

Bell, Harold J; Inoue, Takuya; Shum, Kelly; Luk, Collin; Syed, Naweed I

2007-06-01

Breathing is an essential homeostatic behavior regulated by central neuronal networks, often called central pattern generators (CPGs). Despite ongoing advances in our understanding of the neural control of breathing, the basic mechanisms by which peripheral input modulates the activities of the central respiratory CPG remain elusive. This lack of fundamental knowledge vis-à-vis the role of peripheral influences in the control of the respiratory CPG is due in large part to the complexity of mammalian respiratory control centres. We have therefore developed a simpler invertebrate model to study the basic cellular and synaptic mechanisms by which a peripheral chemosensory input affects the central respiratory CPG. Here we report on the identification and characterization of peripheral chemoreceptor cells (PCRCs) that relay hypoxia-sensitive chemosensory information to the known respiratory CPG neuron right pedal dorsal 1 in the mollusk Lymnaea stagnalis. Selective perfusion of these PCRCs with hypoxic saline triggered bursting activity in these neurons and when isolated in cell culture these cells also demonstrated hypoxic sensitivity that resulted in membrane depolarization and spiking activity. When cocultured with right pedal dorsal 1, the PCRCs developed synapses that exhibited a form of short-term synaptic plasticity in response to hypoxia. Finally, osphradial denervation in intact animals significantly perturbed respiratory activity compared with their sham counterparts. This study provides evidence for direct synaptic connectivity between a peripheral regulatory element and a central respiratory CPG neuron, revealing a potential locus for hypoxia-induced synaptic plasticity underlying breathing behavior.

Dynamic Locomotor Capabilities Revealed by Early Dinosaur Trackmakers from Southern Africa

PubMed Central

Wilson, Jeffrey A.; Marsicano, Claudia A.; Smith, Roger M. H.

2009-01-01

Background A new investigation of the sedimentology and ichnology of the Early Jurassic Moyeni tracksite in Lesotho, southern Africa has yielded new insights into the behavior and locomotor dynamics of early dinosaurs. Methodology/Principal Findings The tracksite is an ancient point bar preserving a heterogeneous substrate of varied consistency and inclination that includes a ripple-marked riverbed, a bar slope, and a stable algal-matted bar top surface. Several basal ornithischian dinosaurs and a single theropod dinosaur crossed its surface within days or perhaps weeks of one another, but responded to substrate heterogeneity differently. Whereas the theropod trackmaker accommodated sloping and slippery surfaces by gripping the substrate with its pedal claws, the basal ornithischian trackmakers adjusted to the terrain by changing between quadrupedal and bipedal stance, wide and narrow gauge limb support (abduction range = 31°), and plantigrade and digitigrade foot posture. Conclusions/Significance The locomotor adjustments coincide with changes in substrate consistency along the trackway and appear to reflect ‘real time’ responses to a complex terrain. It is proposed that these responses foreshadow important locomotor transformations characterizing the later evolution of the two main dinosaur lineages. Ornithischians, which shifted from bipedal to quadrupedal posture at least three times in their evolutionary history, are shown to have been capable of adopting both postures early in their evolutionary history. The substrate-gripping behavior demonstrated by the early theropod, in turn, is consistent with the hypothesized function of pedal claws in bird ancestors. PMID:19806213

Private sector village enterprise a new approach to sustainable financing

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

Gay, C.F.

1997-12-01

This paper presents an enterprise plan for introducing solar power in a rural market, while providing economic development, and hence the ability of the user to pay for the power source. This plan is based on a product called GEEP - a solar sewing machine conversion kit. This kit can be retrofit onto pedal sewing machines and marketed to village tailors in India, as part of a marketing program which includes increased demand for tailored products which will allow the tailors to be able to finance the conversion kits.

Study of optimal training protocols and devices for developing and maintaining physical fitness in females prior to and during space flight

NASA Technical Reports Server (NTRS)

Olree, H. D.; Corbin, B.; Smith, C.

1977-01-01

Pedalling a bicycle at least ten minutes a day at 85% of maximum pulse rate, three days a week for ten weeks will produce moderate increases in overall strength and physical work capacity in college-age females. The longer the training session, up to thirty minutes per session, the greater are the increases in physical work capacity that result when college-age females are trained three days a week for ten weeks at 85% of their maximum heart rate.

An Attempt to Identify Indicators of Competence on Mechanical Maintenance Tasks.

DTIC Science & Technology

1979-01-01

them on the DA Form 2404. The vehicle is prepared as follows: 1. Left front wheel and drum removed. 2. Retracting spring disconnected. 3. Brake pedal...charging system. 8 2. Troubleshoot starting system circuit on Ml51Al/A2 truck. ii 3. Replace steering linkage on Ml5lAl/A2 truck. 8 4. Troubleshoot brakes ...Troubleshoot starting system circuit on MI51AI/A2 truck. 101 3. Replace steering linkage on MI51AI/A2 truck. 96 4. Troubleshoot brakes and controls

Proposal on Calculation of Ventilation Threshold Using Non-contact Respiration Measurement with Pattern Light Projection

NASA Astrophysics Data System (ADS)

Aoki, Hirooki; Ichimura, Shiro; Fujiwara, Toyoki; Kiyooka, Satoru; Koshiji, Kohji; Tsuzuki, Keishi; Nakamura, Hidetoshi; Fujimoto, Hideo

We proposed a calculation method of the ventilation threshold using the non-contact respiration measurement with dot-matrix pattern light projection under pedaling exercise. The validity and effectiveness of our proposed method is examined by simultaneous measurement with the expiration gas analyzer. The experimental result showed that the correlation existed between the quasi ventilation thresholds calculated by our proposed method and the ventilation thresholds calculated by the expiration gas analyzer. This result indicates the possibility of the non-contact measurement of the ventilation threshold by the proposed method.

Macrodystrophia lipomatosa: a reconstructive approach to gigantism of the foot.

PubMed

Watt, Andrew J; Chung, Kevin C

2004-01-01

Localized gigantism poses a challenging surgical dilemma, and it may be treated with amputation. This case report documents the application of a reconstructive approach to a severe case of pedal macrodystrophia lipomatosa in a 1-year-old girl. A series of 3 surgeries were designed to reduce the length, width, height, and overall bulk of the congenitally enlarged foot. The 3 procedures debulked the foot for normal ambulation and same-size shoe wear for both feet. The resulting functional and aesthetic improvements achieved through reconstructive treatment provided a desirable alternative to amputation.

Comparative analysis of speed's impact on muscle demands during partial body weight support motor-assisted elliptical training.

PubMed

Burnfield, Judith M; Irons, Sonya L; Buster, Thad W; Taylor, Adam P; Hildner, Gretchen A; Shu, Yu

2014-01-01

Individuals with walking limitations often experience challenges engaging in functionally relevant exercise. An adapted elliptical trainer (motor to assist pedal movement, integrated body weight harness, ramps/stairs, and grab rails) has been developed to help individuals with physical disabilities and chronic conditions regain/retain walking capacity and fitness. However, limited published studies are available to guide therapeutic interventions. This repeated measures study examined the influence of motor-assisted elliptical training speed on lower extremity muscle demands at four body weight support (BWS) levels commonly used therapeutically for walking. Electromyography (EMG) and pedal trajectory data were recorded as ten individuals without known disability used the motor-assisted elliptical trainer at three speeds [20,40, 60 revolutions per minute (RPM)] during each BWS level (0%, 20%, 40%, 60%). Overall, the EMG activity (peak, mean, duration) in key stabilizer muscles (i.e., gluteus medius, gluteus maximus, vastus lateralis, medial gastrocnemius and soleus) recorded at 60 RPM exceeded those at 40 RPM, which were higher than values at 20 RPM in all but three situations (gluteus medius mean at 0% BWS, vastus lateralis mean at 20% BWS, soleus duration at 40% BWS); however, these differences did not always achieve statistical significance. Slower motor-assisted speeds can be used to accommodate weakness of gluteus medius, gluteus maximus, vastus lateralis, medial gastrocnemius and soleus. As strength improves, training at faster motor-assisted speeds may provide a means to progressively challenge key lower extremity stabilizers. Copyright © 2013 Elsevier B.V. All rights reserved.

Risk factors associated with the severity of injury outcome for paediatric road trauma.

PubMed

Mitchell, R J; Bambach, M R; Foster, K; Curtis, K

2015-05-01

Road trauma is one of the most common causes of injury for children. Yet risk factors associated with different levels of injury severity for childhood road trauma have not been examined in-depth. This study identifies crash and injury risk factors associated with the severity of non-fatal injury outcome for paediatric road trauma. A retrospective analysis was conducted of paediatric road trauma identified in linked police-reported and hospitalisation records during 1 January 2001 to 31 December 2011 in New South Wales (NSW), Australia. The linkage rate was 54%. Injury severity was calculated from diagnosis classifications in hospital records using the International Classification of Disease Injury Severity Score. Univariate and multi-variable logistic regression was conducted. There were 2412 car occupants, 1701 pedestrians and 612 pedal cyclists hospitalised where their hospital record linked to a police report. For car occupants, unauthorised vehicle drivers had twice the odds (OR: 2.21, 95%CI 1.47-3.34) and learner/provisional drivers had one and a half times higher odds (OR: 1.54, 95%CI 1.15-2.07) of a child car occupant sustaining a serious injury compared to a minor injury. For pedal cyclists and pedestrians, there were lower odds of a crash occurring during school commuting time and higher odds of a crash occurring during the weekend or on a dry road for children who sustained a serious versus a minor injury. Injury prevention initiatives, such as restraint and helmet use, that should reduce injury and/or crash severity are advocated. Copyright © 2015 Elsevier Ltd. All rights reserved.

Activation of the serotonergic system by pedaling exercise changes anterior cingulate cortex activity and improves negative emotion.

PubMed

Ohmatsu, Satoko; Nakano, Hideki; Tominaga, Takanori; Terakawa, Yuzo; Murata, Takaho; Morioka, Shu

2014-08-15

Pedaling exercise (PE) of moderate intensity has been shown to ease anxiety and discomfort; however, little is known of the changes that occur in brain activities and in the serotonergic (5-HT) system after PE. Therefore, this study was conducted for the following reasons: (1) to localize the changes in the brain activities induced by PE using a distributed source localization algorithm, (2) to examine the changes in frontal asymmetry, as used in the Davidson model, with electroencephalography (EEG) activity, and (3) to examine the effect of PE on the 5-HT system. A 32-channel EEG was used to record before and after PE. Profile of Mood States tests indicated that there was a significant decrease in tension-anxiety and a significant increase in vigor after PE. A standardized low-resolution brain electromagnetic tomography analysis showed a significant decrease in brain activities after PE in the alpha-2 band (10-12.5 Hz) in the anterior cingulate cortex (ACC). Moreover, a significant increase in frontal EEG asymmetry was observed after PE in the alpha-1 band (7.5-10 Hz). Urine 5-HT levels significantly increased after PE. Urine 5-HT levels positively correlated with the degree of frontal EEG asymmetry in the alpha-1 band and negatively correlated with brain activity in ACC. Our results suggested that PE activates the 5-HT system and consequently induces increases in frontal EEG asymmetry in the alpha-1 band and reductions of brain activity in the alpha-2 band in the ACC region. Copyright © 2014 Elsevier B.V. All rights reserved.

The effects of paired associative stimulation on knee extensor motor excitability of individuals post-stroke: A pilot study

PubMed Central

Rogers, Lynn M.; Brown, David A.; Stinear, James W.

2012-01-01

Objective Paired associative stimulation (PAS) modulates bilateral distal lower limb motor pathways during walking. We assessed the effects of inhibitory PAS applied to the vastus medialis (VM) motor pathways of chronic stroke patients. Methods PAS consisted of 120 electrical stimuli applied to the femoral nerve paired with transcranial magnetic stimulation (TMS) of the lower limb primary motor cortex so that the estimated arrival of the afferent volley occurred 8 ms after delivery of the magnetic stimulus. Stimulus pairs were delivered to the non-paretic VM motor system of 11 chronic stroke patients and the right limb motor system of 11 non-impaired subjects at 0.19 Hz. The effects of PAS on VM motor pathway excitability and muscle activity were assessed during pedaling. TMS-induced motor evoked potential (MEP) amplitudes and the percent of VM activity in the flexion phase of active pedaling (%FLEXVM) was examined before and after PAS. Results Inhibitory PAS reduced VM MEP amplitudes in the target limb (p < 0.05) of both groups, while post-PAS paretic VM MEP amplitudes increased for some patients and decreased for others. Group mean paretic limb %FLEXVM was not altered by inhibitory PAS. Conclusions These results indicate PAS can be used to manipulate motor cortical excitability in proximal lower limb representations, however the sign of induced modulation was unpredictable and cyclic muscle activity was not modified. Significance The study has important implications for the development of therapies involving non-invasive brain stimulation to modify abnormal motor behavior following stroke. PMID:21130032

Target innervation is necessary for neuronal polyploidization in the terrestrial slug Limax.

PubMed

Matsuo, Ryota; Yamagishi, Miki; Wakiya, Kyoko; Tanaka, Yoko; Ito, Etsuro

2013-05-30

The brain of gastropod mollusks contains many giant neurons with polyploid genomic DNAs. Such DNAs are generated through repeated DNA endoreplication during body growth. However, it is not known what triggers DNA endoreplication in neurons. There are two possibilities: (1) DNAs are replicated in response to some unknown molecules in the hemolymph that reflect the nutritive status of the animal; or (2) DNAs are replicated in response to some unknown factors that are retrogradely transported through axons from the innervated target organs. We first tested whether hemolymph with rich nutrition could induce DNA endoreplication. We tested whether the transplanted brain exhibits enhanced DNA endoreplication like an endogenous brain does when transplanted into the homocoel of the body of a slug whose body growth is promoted by an increased food supply. However, no enhancement was observed in the frequency of DNA endoreplication when we compared the transplanted brains in the growth-promoted and growth-suppressed host slugs, suggesting that the humoral environment is irrelevant to triggering the body growth-dependent DNA endoreplication. Next, we tested the requirement of target innervation by surgically dissecting a unilateral posterior pedal nerve of an endogenous brain. Substantially lower number of neurons exhibited DNA endoreplication in the pedal ganglion ipsilateral to the dissected nerve. These results support the view that enhanced DNA endoreplication is mediated by target innervation and is not brought about through the direct effect of humoral factors in the hemolymph during body growth. © 2013 Wiley Periodicals, Inc. Develop Neurobiol, 2013. Copyright © 2013 Wiley Periodicals, Inc.

Can FES-Augmented Active Cycling Training Improve Locomotion in Post-Acute Elderly Stroke Patients?

PubMed Central

Peri, Elisabetta; Ambrosini, Emilia; Pedrocchi, Alessandra; Ferrigno, Giancarlo; Nava, Claudia; Longoni, Valentina; Monticone, Marco; Ferrante, Simona

2016-01-01

Recent studies advocated the use of active cycling coupled with functional electrical stimulation to induce neuroplasticity and enhance functional improvements in stroke adult patients. The aim of this work was to evaluate whether the benefits induced by such a treatment are superior to standard physiotherapy. A single-blinded randomized controlled trial has been performed on post-acute elderly stroke patients. Patients underwent FES-augmented cycling training combined with voluntary pedaling or standard physiotherapy. The intervention consisted of fifteen 30-minutes sessions carried out within 3 weeks. Patients were evaluated before and after training, through functional scales, gait analysis and a voluntary pedaling test. Results were compared with an age-matched healthy group. Sixteen patients completed the training. After treatment, a general improvement of all clinical scales was obtained for both groups. Only the mechanical efficiency highlighted a group effect in favor of the experimental group. Although a group effect was not found for any other cycling or gait parameters, the experimental group showed a higher percentage of change with respect to the control group (e.g. the gait velocity was improved of 35.4% and 25.4% respectively, and its variation over time was higher than minimal clinical difference for the experimental group only). This trend suggests that differences in terms of motor recovery between the two groups may be achieved increasing the training dose. In conclusion, this study, although preliminary, showed that FES-augmented active cycling training seems to be effective in improving cycling and walking ability in post-acute elderly stroke patients. A higher sample size is required to confirm results. PMID:27990234

Can FES-Augmented Active Cycling Training Improve Locomotion in Post-Acute Elderly Stroke Patients?

PubMed

Peri, Elisabetta; Ambrosini, Emilia; Pedrocchi, Alessandra; Ferrigno, Giancarlo; Nava, Claudia; Longoni, Valentina; Monticone, Marco; Ferrante, Simona

2016-06-13

Recent studies advocated the use of active cycling coupled with functional electrical stimulation to induce neuroplasticity and enhance functional improvements in stroke adult patients. The aim of this work was to evaluate whether the benefits induced by such a treatment are superior to standard physiotherapy. A single-blinded randomized controlled trial has been performed on post-acute elderly stroke patients. Patients underwent FES-augmented cycling training combined with voluntary pedaling or standard physiotherapy. The intervention consisted of fifteen 30-minutes sessions carried out within 3 weeks. Patients were evaluated before and after training, through functional scales, gait analysis and a voluntary pedaling test. Results were compared with an age-matched healthy group. Sixteen patients completed the training. After treatment, a general improvement of all clinical scales was obtained for both groups. Only the mechanical efficiency highlighted a group effect in favor of the experimental group. Although a group effect was not found for any other cycling or gait parameters, the experimental group showed a higher percentage of change with respect to the control group (e.g. the gait velocity was improved of 35.4% and 25.4% respectively, and its variation over time was higher than minimal clinical difference for the experimental group only). This trend suggests that differences in terms of motor recovery between the two groups may be achieved increasing the training dose. In conclusion, this study, although preliminary, showed that FES-augmented active cycling training seems to be effective in improving cycling and walking ability in post-acute elderly stroke patients. A higher sample size is required to confirm results.

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

Jens, Sjoerd, E-mail: s.jens@amc.uva.nl; Lucatelli, Pierleone, E-mail: pierleone.lucatelli@gmail.com; Koelemay, Mark J. W., E-mail: m.j.koelemaij@amc.uva.nl

Purpose. To evaluate the additional value of three-dimensional rotational angiography (3DRA) of the foot compared with digital subtraction angiography (DSA) in patients with critical limb ischemia (CLI). Technique. For 3DRA, the C-arm was placed in the propeller position with the foot in an isocentric position. The patient's unaffected foot was positioned in a footrest outside the field of view. For correct timing of 3DRA, the delay from contrast injection in the popliteal artery at the level of knee joint to complete pedal arterial enhancement was assessed using DSA. With this delay, 3DRA was started after injection of 15 ml contrast.more » Imaging of the 3DRA could directly be reconstructed and visualized.Materials and MethodsPatients undergoing 3DRA of the foot were prospectively registered. DSA and 3DRA images were scored separately for arterial patency and presence of collaterals. Treatment strategies were proposed based on DSA with and without the availability of 3DRA. Results. Eleven patients underwent 3DRA of the foot. One 3DRA was not included because the acquisition was focused on the heel instead of the entire foot. Diagnostic quality of 3DRA was good in all ten patients. 3DRA compared with DSA showed additional patent arteries in six patients, patent plantar arch in three patients, and collaterals between the pedal arteries in five patients. Additional information from 3DRA resulted in a change of treatment strategy in six patients. Conclusion, 3DRA of the foot contains valuable additional real-time information to better guide peripheral vascular interventions in patients with CLI and nonhealing tissue lesions.« less

Development of a Field-Deployable Psychomotor Vigilance Test to Monitor Helicopter Pilot Performance.

PubMed

McMahon, Terry W; Newman, David G

2016-04-01

Flying a helicopter is a complex psychomotor skill. Fatigue is a serious threat to operational safety, particularly for sustained helicopter operations involving high levels of cognitive information processing and sustained time on task. As part of ongoing research into this issue, the object of this study was to develop a field-deployable helicopter-specific psychomotor vigilance test (PVT) for the purpose of daily performance monitoring of pilots. The PVT consists of a laptop computer, a hand-operated joystick, and a set of rudder pedals. Screen-based compensatory tracking task software includes a tracking ball (operated by the joystick) which moves randomly in all directions, and a second tracking ball which moves horizontally (operated by the rudder pedals). The 5-min test requires the pilot to keep both tracking balls centered. This helicopter-specific PVT's portability and integrated data acquisition and storage system enables daily field monitoring of the performance of individual helicopter pilots. The inclusion of a simultaneous foot-operated tracking task ensures divided attention for helicopter pilots as the movement of both tracking balls requires simultaneous inputs. This PVT is quick, economical, easy to use, and specific to the operational flying task. It can be used for performance monitoring purposes, and as a general research tool for investigating the psychomotor demands of helicopter operations. While reliability and validity testing is warranted, data acquired from this test could help further our understanding of the effect of various factors (such as fatigue) on helicopter pilot performance, with the potential of contributing to helicopter operational safety.

Acute bilateral iliac artery occlusion secondary to blunt trauma: successful endovascular treatment.

PubMed

Sternbergh, W Charles; Conners, Michael S; Ojeda, Melissa A; Money, Samuel R

2003-09-01

Endovascular treatment of blunt vascular trauma has been infrequently reported. A 27-year-old man was crushed between a fork-lift truck and a concrete platform. The physical examination was remarkable for hemodynamic stability, significant lower abdominal ecchymosis and tenderness, obvious pelvic fracture, and gross hematuria. Vascular examination revealed no femoral pulses, no pedal signals bilaterally, and minimal left leg and no right leg motor function. Arteriograms revealed right common iliac artery and external iliac artery occlusion and a 2-cm near occlusion of the left external iliac artery. In the operating room, bilateral common femoral artery access was obtained, and retrograde arteriogram on the right side demonstrated free extravasation of contrast material at the level of the proximal external iliac artery. An angled glide wire was successfully traversed over the vascular injury, and two covered stents (Wallgraft, 10 x 50 mm and 8 x 30 mm) were deployed. The left iliac injury was similarly treated with an 8 x 30-mm covered stent. After calf fasciotomy, exploratory laparotomy revealed a severe sigmoid colon degloving injury, requiring resection and colostomy. A suprapubic catheter was placed because of bladder rupture, and an open-book pelvic fracture was treated with external fixation. Postoperatively the patient regained palpable bilateral pedal pulses and normal left leg function, but right leg paralysis persisted secondary to severe lumbar plexus nerve injury. Endovascular repair of blunt intra-abdominal arterial injuries is possible and should be particularly considered when fecal contamination, pelvic hematoma, or multiple associated injuries make conventional repair problematic.

Treatment with medium chain fatty acids milk of CD36-deficient preschool children.

PubMed

Nagasaka, Hironori; Hirano, Ken-Ichi; Yorifuji, Tohru; Komatsu, Haruki; Takatani, Tomonozumi; Morioka, Ichiro; Hirayama, Satoshi; Miida, Takashi

2018-06-01

CD36 deficiency is characterized by limited cellular long chain fatty acid uptake in the skeletal and cardiac muscles and often causes energy crisis in these muscles. However, suitable treatment for CD36 deficiency remains to be established. The aim of this study was to evaluate the clinical and metabolic effects of medium chain triacylglycerols (MCTs) in two CD36-deficient preschool children who often developed fasting hypoglycemia and exercise-induced myalgia. Fasting blood glucose, total ketone bodies, and free fatty acids were examined and compared for usual supper diets and for diets with replacement of one component with 2 g/kg of 9% MCT-containing milk (MCT milk). Changes in serum creatine kinase and alanine aminotransferase levels, resulting from replacement of glucose water intake with 1 g/kg of MCT milk and determined by using bicycle pedaling tasks, were examined and compared. Hypoglycemic and/or myalgia episodes in daily life were also investigated. Biochemically, participants' blood glucose and total ketone bodies levels after overnight fasting substantially increased after dietary suppers containing MCT milk. Increases in serum creatine kinase and alanine aminotransferase levels resulting from the bicycle pedaling task were suppressed by MCT milk. Hypoglycemia leading to unconsciousness and tachycardia before breakfast decreased after introduction of dietary suppers containing MCT milk. Occurrence of myalgia in the lower limbs also decreased after intakes of MCT milk before long and/or strenuous exercising. Our results suggest that MCTs can prevent fasting hypoglycemia and exercise-induced myalgia in CD36-deficient young children. Copyright © 2017 Elsevier Inc. All rights reserved.

Grasping primate development: Ontogeny of intrinsic hand and foot proportions in capuchin monkeys (Cebus albifrons and Sapajus apella).

PubMed

Young, Jesse W; Heard-Booth, Amber N

2016-09-01

Young primates have relatively large hands and feet for their body size, perhaps enhancing grasping ability. We test the hypothesis that selection for improved grasping ability is responsible for these scaling trends by examining the ontogeny of intrinsic hand and foot proportions in capuchin monkeys (Cebus albifrons and Sapajus apella). If selection for improved grasping ability is responsible for the observed patterns of hand and foot growth in primates, we predicted that fingers and toes would be longer early in life and proportionally decline with age. We measured the lengths of manual and pedal metapodials and phalanges in a mixed-longitudinal radiographic sample. Bone lengths were (a) converted into phalangeal indices (summed non-distal phalangeal length/metapodial length) to test for age-related changes in intrinsic proportions and (b) fit to Gompertz models of growth to test for differences in the dynamics of phalangeal versus metapodial growth. Manual and pedal phalangeal indices nearly universally decreased with age in capuchin monkeys. Growth curve analyses revealed that metapodials generally grew at a faster rate, and for a longer duration, than corresponding phalanges. Our findings are consistent with the hypothesis that primates are under selection for increased grasping ability early in life. Relatively long digits may be functionally adaptive for growing capuchins, permitting a more secure grasp on both caregivers and arboreal supports, as well as facilitating early foraging. Additional studies of primates and other mammals, as well as tests of grasping performance, are required to fully evaluate the adaptive significance of primate hand and foot growth. © 2016 Wiley Periodicals, Inc.

In dubio pro silentio – Even Loud Music Does Not Facilitate Strenuous Ergometer Exercise

PubMed Central

Kreutz, Gunter; Schorer, Jörg; Sojke, Dominik; Neugebauer, Judith; Bullack, Antje

2018-01-01

Background: Music listening is wide-spread in amateur sports. Ergometer exercise is one such activity which is often performed with loud music. Aim and Hypotheses: We investigated the effects of electronic music at different intensity levels on ergometer performance (physical performance, force on the pedal, pedaling frequency), perceived fatigue and heart rate in healthy adults. We assumed that higher sound intensity levels are associated with greater ergometer performance and less perceived effort, particularly for untrained individuals. Methods: Groups of high trained and low trained healthy males (N = 40; age = 25.25 years; SD = 3.89 years) were tested individually on an ergometer while electronic dance music was played at 0, 65, 75, and 85 dB. Participants assessed their music experience during the experiment. Results: Majorities of participants rated the music as not too loud (65%), motivating (77.50%), appropriate for this sports exercise (90%), and having the right tempo (67.50%). Participants noticed changes in the acoustical environment with increasing intensity levels, but no further effects on any of the physical or other subjective measures were found for neither of the groups. Therefore, the main hypothesis must be rejected. Discussion: These findings suggest that high loudness levels do not positively influence ergometer performance. The high acceptance of loud music and perceived appropriateness could be based on erroneous beliefs or stereotypes. Reasons for the widespread use of loud music in fitness sports needs further investigation. Reducing loudness during fitness exercise may not compromise physical performance or perceived effort. PMID:29867622

Forced, not voluntary, exercise improves motor function in Parkinson's disease patients.

PubMed

Ridgel, Angela L; Vitek, Jerrold L; Alberts, Jay L

2009-01-01

Animal studies indicate forced exercise (FE) improves overall motor function in Parkinsonian rodents. Global improvements in motor function following voluntary exercise (VE) are not widely reported in human Parkinson's disease (PD) patients. The aim of this study was to compare the effects of VE and FE on PD symptoms, motor function, and bimanual dexterity. Ten patients with mild to moderate PD were randomly assigned to complete 8 weeks of FE or VE. With the assistance of a trainer, patients in the FE group pedaled at a rate 30% greater than their preferred voluntary rate, whereas patients in the VE group pedaled at their preferred rate. Aerobic intensity for both groups was identical, 60% to 80% of their individualized training heart rate. Aerobic fitness improved for both groups. Following FE, Unified Parkinson's Disease Rating Scale (UPDRS) motor scores improved 35%, whereas patients completing VE did not exhibit any improvement. The control and coordination of grasping forces during the performance of a functional bimanual dexterity task improved significantly for patients in the FE group, whereas no changes in motor performance were observed following VE. Improvements in clinical measures of rigidity and bradykinesia and biomechanical measures of bimanual dexterity were maintained 4 weeks after FE cessation. Aerobic fitness can be improved in PD patients following both VE and FE interventions. However, only FE results in significant improvements in motor function and bimanual dexterity. Biomechanical data indicate that FE leads to a shift in motor control strategy, from feedback to a greater reliance on feedforward processes, which suggests FE may be altering central motor control processes.

The effects of paired associative stimulation on knee extensor motor excitability of individuals post-stroke: a pilot study.

PubMed

Rogers, Lynn M; Brown, David A; Stinear, James W

2011-06-01

Paired associative stimulation (PAS) modulates bilateral distal lower limb motor pathways during walking. We assessed the effects of inhibitory PAS applied to the vastus medialis (VM) motor pathways of chronic stroke patients. PAS consisted of 120 electrical stimuli applied to the femoral nerve paired with transcranial magnetic stimulation (TMS) of the lower limb primary motor cortex so that the estimated arrival of the afferent volley occurred 8 ms after delivery of the magnetic stimulus. Stimulus pairs were delivered to the non-paretic VM motor system of 11 chronic stroke patients and the right limb motor system of 11 non-impaired subjects at 0.19 Hz. The effects of PAS on VM motor pathway excitability and muscle activity were assessed during pedaling. TMS-induced motor evoked potential (MEP) amplitudes and the percent of VM activity in the flexion phase of active pedaling (% FLEXVM) was examined before and after PAS. Inhibitory PAS reduced VM MEP amplitudes in the target limb (p<0.05) of both groups, while post-PAS paretic VM MEP amplitudes increased for some patients and decreased for others. Group mean paretic limb % FLEXVM was not altered by inhibitory PAS. These results indicate PAS can be used to manipulate motor cortical excitability in proximal lower limb representations, however the sign of induced modulation was unpredictable and cyclic muscle activity was not modified. The study has important implications for the development of therapies involving non-invasive brain stimulation to modify abnormal motor behavior following stroke. Copyright © 2010 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Comparative mapping of GABA-immunoreactive neurons in the central nervous systems of nudibranch molluscs.

PubMed

Gunaratne, Charuni A; Sakurai, Akira; Katz, Paul S

2014-03-01

The relative simplicity of certain invertebrate nervous systems, such as those of gastropod molluscs, allows behaviors to be dissected at the level of small neural circuits composed of individually identifiable neurons. Elucidating the neurotransmitter phenotype of neurons in neural circuits is important for understanding how those neural circuits function. In this study, we examined the distribution of γ-aminobutyric-acid;-immunoreactive (GABA-ir) neurons in four species of sea slugs (Mollusca, Gastropoda, Opisthobranchia, Nudibranchia): Tritonia diomedea, Melibe leonina, Dendronotus iris, and Hermissenda crassicornis. We found consistent patterns of GABA immunoreactivity in the pedal and cerebral-pleural ganglia across species. In particular, there were bilateral clusters in the lateral and medial regions of the dorsal surface of the cerebral ganglia as well as a cluster on the ventral surface of the pedal ganglia. There were also individual GABA-ir neurons that were recognizable across species. The invariant presence of these individual neurons and clusters suggests that they are homologous, although there were interspecies differences in the numbers of neurons in the clusters. The GABAergic system was largely restricted to the central nervous system, with the majority of axons confined to ganglionic connectives and commissures, suggesting a central, integrative role for GABA. GABA was a candidate inhibitory neurotransmitter for neurons in central pattern generator (CPG) circuits underlying swimming behaviors in these species, however none of the known swim CPG neurons were GABA-ir. Although the functions of these GABA-ir neurons are not known, it is clear that their presence has been strongly conserved across nudibranchs. Copyright © 2013 Wiley Periodicals, Inc.

Microcephaly/lymphedema and terminal deletion of the long arm of chromosome 13

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

Fryns, J.P.

1995-07-03

Recently, we examined a 2-year-old boy with the association of microcephaly and significant pedal edema that extended to the distal parts of the legs. Prometaphase chromosome studies showed a small terminal deletion in the long arm of chromosome 13 of band 13q34, karyotype 46,XY,del(13)(q34{yields}qter). The present finding of a small terminal 13q34 deletion in this young boy with microcephaly/lymphedema is a first indication that the lymphedema/microcephaly association can be due to a small terminal 13q deletion. 2 refs.

Management of pedal puncture wounds.

PubMed

Belin, Ronald; Carrington, Scott

2012-07-01

Puncture wounds of the foot are a common injury, and infection associated with these injuries may result in considerable morbidity. The pathophysiology and management of a puncture wound is dependent on the material that punctures the foot, the location and depth of the wound, time to presentation, footwear, and underlying health status of the patient. Puncture wounds should not be treated lightly, so accurate diagnosis, assessment, and treatment are paramount. Early incision and drainage, vaccination, and the use of proper antibiotics can lead to positive outcomes and prevent limb-threatening circumstances. Copyright © 2012 Elsevier Inc. All rights reserved.

Cockpit integration from a pilot's point of view

NASA Technical Reports Server (NTRS)

Green, D. L.

1982-01-01

Extensive experience in both operational and engineering test flight was used to suggest straightforward changes to helicopter cockpit and control system design that would improve pilot performance in marginal and instrument flight conditions. Needed control system improvements considered include: (1) separation of yaw from cyclic force trim; (2) pedal force proportional to displacement rate; and (3) integration of engine controls in collective stick. Display improvements needed include: (1) natural cuing of yaw rate in attitude indicator; (2) collective position indication and radar altimeter placed within primary scan; and (3) omnidirectional display of full range airspeed data.

A flight simulator control system using electric torque motors

NASA Technical Reports Server (NTRS)

Musick, R. O.; Wagner, C. A.

1975-01-01

Control systems are required in flight simulators to provide representative stick and rudder pedal characteristics. A system has been developed that uses electric dc torque motors instead of the more common hydraulic actuators. The torque motor system overcomes certain disadvantages of hydraulic systems, such as high cost, high power consumption, noise, oil leaks, and safety problems. A description of the torque motor system is presented, including both electrical and mechanical design as well as performance characteristics. The system develops forces sufficiently high for most simulations, and is physically small and light enough to be used in most motion-base cockpits.

Principles of laser surgery. Advantages and disadvantages.

PubMed

Ballow, E B

1992-07-01

An attempt has been made in this article to present an honest and accurate state-of-art narrative of laser surgery for pedal conditions. The theory of operation, physiologic effects and procedural comparisons have been presented regarding those procedures and lasers that are available for use by podiatric surgeons and others treating the foot and leg. Although some information described within this article is anecdotal, it is elaborated with representative expert material from the scientific literature. Overall, a sound theoretic understanding of the mode of action of lasers and extensive training and experience is encouraged when engaging in this exciting discipline of surgery.

Baseline tests of the power-train electric delivery van

NASA Technical Reports Server (NTRS)

Lumannick, S.; Dustin, M. O.; Bozek, J. M.

1977-01-01

Vehicle maximum speed, range at constant speed, range over stop-and-go driving schedules, maximum acceleration, gradeability, gradeability limit, road energy consumption, road power, indicated energy consumption, braking capability, battery charger efficiency, and battery characteristics were determined for a modified utility van powered by sixteen 6-volt batteries connected in series. A chopper controller actuated by a foot accelerator pedal changes the voltage applied to the 22-kilowatt (30-hp) series-wound drive motor. In addition to the conventional hydraulic braking system, the vehicle has hydraulic regenerative braking. Cycle tests and acceleration tests were conducted with and without hydraulic regeneration.

Antiulcerogenic and antiinflammatory studies with shilajit.

PubMed

Goel, R K; Banerjee, R S; Acharya, S B

1990-04-01

In folk medicine, shilajit has been used to treat diverse clinical conditions ranging from peptic ulcer to bone healing. The present study was conducted to evaluate the possible antiulcerogenic and antiinflammatory activities of shilajit obtained from the rocky mountains of Zarlek, Badekshan, Afghanistan. Shilajit increased the carbohydrate/protein ratio and decreased gastric ulcer index, indicating an increased mucus barrier. Shilajit was found to have significant antiinflammatory effect in carrageenan-induced acute pedal oedema, granuloma pouch and adjuvant-induced arthritis in rats. The results of the present study thus substantiate the use of shilajit in peptic ulcer and inflammation.

Motor adaptation to prosthetic cycling in people with trans-tibial amputation

PubMed Central

Childers, W. Lee; Prilutsky, Boris I.; Gregor, Robert J.

2014-01-01

The neuromusculoskeletal system interacts with the external environment via end-segments, e.g. feet. A person with trans-tibial amputation (TTAmp) has lost a foot and ankle; hence the residuum with prosthesis becomes the new end-segment. We investigated changes in kinetics and muscle activity in TTAmps during cycling with this altered interface with the environment. Nine unilateral TTAmps and nine subjects without amputation (NoAmp) pedaled at a constant torque of 15Nm and a constant cadence of 90rpm (~150watts). Pedal forces and limb kinematics were used to calculate resultant joint moments. Electromyographic activity was recorded to determine its magnitude and timing. Biomechanical and EMG variables of the amputated limb were compared to those of the TTAmp sound limb and to the dominant limb in the NoAmp group using a one-way ANOVA. Results showed maximum angular displacement between the residuum and prosthesis was 4.8 ± 1.8deg. The amputated limb compared to sound limb and NoAmp group produced lower extensor moments averaged over the cycle about the ankle (13 ± 2.3, 20 ± 5.7, and 19 ± 5.3Nm, respectfully) and knee (8.4 ± 5.0, 15 ± 4.5, and 12.7 ± 5.9Nm, respectfully) (p<0.05). Gastrocnemius and rectus femoris peak activity in the TTAmps shifted to later in the crank cycle (by 36° and 75°, respectfully; p<0.05). These data suggest gastrocnemius was utilized as a one-joint knee flexor in combination with rectus femoris for prosthetic socket control and highlight prosthetic control as an interaction between the residuum, prosthesis and external environment. PMID:24818794

Effect of Seat Tube Angle and Exercise Intensity on Muscle Activity Patterns in Cyclists

PubMed Central

DUGGAN, WILL; DONNE, BERNARD; FLEMING, NEIL

2017-01-01

Previous studies have reported improved efficiency at steeper seat tube angle (STA) during ergometer cycling; however, neuromuscular mechanisms have yet to be fully determined. The current study investigated effects of STA on lower limb EMG activity at varying exercise intensities. Cyclists (n=11) were tested at 2 workloads; 160W and an individualised workload (IWL) equivalent to lactate threshold (TLac) minus 10%δ (derived from maximal incremental data), using 3 STA (70, 75 and 80°). Electromyographic data from Vastus Medialis (VM), Rectus Femoris (RF), Vastus Lateralis (VL) and Biceps Femoris (BF) were assessed. The timing and magnitude of activation were quantified and analysed using a two-way ANOVA. STA had significant (P < 0.05) effects on timing of onset and offset of VM, timing of offset of VL, and angle at peak for RF, all occurring later at 80 vs. 70° STA at IWL. In RF, increased activity occurred during the first 108° of the crank cycle at 80 vs. 70° at IWL (P < 0.01). As most of the power in the pedal stroke is generated during the mid-section of the down-stroke, movement of the activation range of knee extensors into the predominantly power phase of the pedal stroke would potentially account for increased efficiency and decreased cardio-respiratory costs. Greater activity of bi-articular RF, in the first 108º of the crank cycle at IWL (80 vs. 70º) may more closely resemble the pelvic stabilising activity of RF in running biomechanics; and potentially explain the more effective transition from cycling to running reported in triathletes using steeper STA. PMID:29399245

A new troodontid theropod, Talos sampsoni gen. et sp. nov., from the Upper Cretaceous Western Interior Basin of North America.

PubMed

Zanno, Lindsay E; Varricchio, David J; O'Connor, Patrick M; Titus, Alan L; Knell, Michael J

2011-01-01

Troodontids are a predominantly small-bodied group of feathered theropod dinosaurs notable for their close evolutionary relationship with Avialae. Despite a diverse Asian representation with remarkable growth in recent years, the North American record of the clade remains poor, with only one controversial species--Troodon formosus--presently known from substantial skeletal remains. Here we report a gracile new troodontid theropod--Talos sampsoni gen. et sp. nov.--from the Upper Cretaceous Kaiparowits Formation, Utah, USA, representing one of the most complete troodontid skeletons described from North America to date. Histological assessment of the holotype specimen indicates that the adult body size of Talos was notably smaller than that of the contemporary genus Troodon. Phylogenetic analysis recovers Talos as a member of a derived, latest Cretaceous subclade, minimally containing Troodon, Saurornithoides, and Zanabazar. MicroCT scans reveal extreme pathological remodeling on pedal phalanx II-1 of the holotype specimen likely resulting from physical trauma and subsequent infectious processes. Talos sampsoni adds to the singularity of the Kaiparowits Formation dinosaur fauna, which is represented by at least 10 previously unrecognized species including the recently named ceratopsids Utahceratops and Kosmoceratops, the hadrosaurine Gryposaurus monumentensis, the tyrannosaurid Teratophoneus, and the oviraptorosaurian Hagryphus. The presence of a distinct troodontid taxon in the Kaiparowits Formation supports the hypothesis that late Campanian dinosaurs of the Western Interior Basin exhibited restricted geographic ranges and suggests that the taxonomic diversity of Late Cretaceous troodontids from North America is currently underestimated. An apparent traumatic injury to the foot of Talos with evidence of subsequent healing sheds new light on the paleobiology of deinonychosaurians by bolstering functional interpretations of prey grappling and/or intraspecific combat for the second pedal digit, and supporting trackway evidence indicating a minimal role in weight bearing.

Robotics and systems technology for advanced endoscopic procedures: experiences in general surgery.

PubMed

Schurr, M O; Arezzo, A; Buess, G F

1999-11-01

The advent of endoscopic techniques changed surgery in many regards. This paper intends to describe an overview about technologies to facilitate endoscopic surgery. The systems described have been developed for the use in general surgery, but an easy application also in the field of cardiac surgery seems realistic. The introduction of system technology and robotic technology enables today to design a highly ergonomic solo-surgery platform. To relief the surgeon from fatigue we developed a new chair dedicated to the functional needs of endoscopic surgery. The foot pedals for high frequency, suction and irrigation are integrated into the basis of the chair. The chair is driven by electric motors controlled with an additional foot pedal joystick to achieve the desired position in the OR. A major enhancement for endoscopic technology is the introduction of robotic technology to design assisting devices for solo-surgery and manipulators for microsurgical instrumentation. A further step in the employment of robotic technology is the design of 'master-slave manipulators' to provide the surgeon with additional degrees of freedom of instrumentation. In 1996 a first prototype of an endoscopic manipulator system. named ARTEMIS, could be used in experimental applications. The system consists of a user station (master) and an instrument station (slave). The surgeon sits at a console which integrates endoscopic monitors, communication facilities and two master devices to control the two slave arms which are mounted to the operating table. Clinical use of the system, however, will require further development in the area of slave mechanics and the control system. Finally the implementation of telecommunication technology in combination with robotic instruments will open new frontiers, such as teleconsulting, teleassistance and telemanipulation.

Crepidula Slipper Limpets Alter Sex Change in Response to Physical Contact with Conspecifics.

PubMed

Carrillo-Baltodano, Allan; Collin, Rachel

2015-12-01

Chemical signaling, especially signaling with waterborne cues, is an important mode of communication between conspecifics of aquatic organisms. Although conspecific associations play an important role in sex allocation of sequential hermaphroditic slipper limpets, the mode of signaling is unknown. We tested the hypothesis that the effects of conspecifics on animal size and time of sex change in the tropical slipper limpet Crepidula cf. marginalis are mediated by waterborne cues. In our experiment, pairs of snails (one small and one large) were kept in cups, either together or partitioned off with fine or coarse mesh, or partitioned, but switched from side to side to allow contact with the cup mate's pedal mucus. The larger snails that were allowed contact with the smaller companions grew faster, and generally changed sex sooner, than did the larger snails in the barrier treatments, which allowed no physical contact. The smaller snails that were allowed contact with the larger cup mate delayed sex change compared to those separated from their cup mates. We were, therefore, able to reject the hypothesis that waterborne cues mediate communication between these snails. Our results suggest that the cue that affects size and time to sex change requires some kind of physical interaction that is lost when the snails are separated. Furthermore, contact with another snail's pedal mucus does not compensate for the loss of physical contact. Since males often attach to the shell of larger females, direct contact may mediate this kind of physical interaction via positional information, physical stimulation, or contact-based chemical communication. Whatever the cue, contact with conspecifics influences both partners, resulting in, surprisingly, a higher growth rate in the larger animal and delayed sex change in the smaller animal. © 2015 Marine Biological Laboratory.

Simulation center training as a means to improve resident performance in percutaneous noncontinuous CT-guided fluoroscopic procedures with dose reduction.

PubMed

Mendiratta-Lala, Mishal; Williams, Todd R; Mendiratta, Vivek; Ahmed, Hafeez; Bonnett, John W

2015-04-01

The purpose of this study was to evaluate the effectiveness of a multifaceted simulation-based resident training for CT-guided fluoroscopic procedures by measuring procedural and technical skills, radiation dose, and procedure times before and after simulation training. A prospective analysis included 40 radiology residents and eight staff radiologists. Residents took an online pretest to assess baseline procedural knowledge. Second-through fourth-year residents' baseline technical skills with a procedural phantom were evaluated. First-through third-year residents then underwent formal didactic and simulation-based procedural and technical training with one of two interventional radiologists and followed the training with 1 month of supervised phantom-based practice. Thereafter, residents underwent final written and practical examinations. The practical examination included essential items from a 20-point checklist, including site and side marking, consent, time-out, and sterile technique along with a technical skills portion assessing pedal steps, radiation dose, needle redirects, and procedure time. The results indicated statistically significant improvement in procedural and technical skills after simulation training. For residents, the median number of pedal steps decreased by three (p=0.001), median dose decreased by 15.4 mGy (p<0.001), median procedure time decreased by 4.0 minutes (p<0.001), median number of needle redirects decreased by 1.0 (p=0.005), and median number of 20-point checklist items successfully completed increased by three (p<0.001). The results suggest that procedural skills can be acquired and improved by simulation-based training of residents, regardless of experience. CT simulation training decreases procedural time, decreases radiation dose, and improves resident efficiency and confidence, which may transfer to clinical practice with improved patient care and safety.

Intraperitoneal Continuous-Rate Infusion for the Maintenance of Anesthesia in Laboratory Mice (Mus musculus)

PubMed Central

Erickson, Rebecca L; Terzi, Matthew C; Jaber, Samer M; Hankenson, F Claire; McKinstry-Wu, Andrew; Kelz, Max B; Marx, James O

2016-01-01

Intraperitoneal injectable anesthetics are often used to achieve surgical anesthesia in laboratory mice. Because bolus redosing of injectable anesthetics can cause unacceptably high mortality, we evaluated intraperitoneal continuous-rate infusion (CRI) of ketamine with or without xylazine for maintaining surgical anesthesia for an extended period of time. Anesthesia was induced in male C57BL/6J mice by using ketamine (80 mg/kg) and xylazine (8 mg/kg) without or with acepromazine at 0.1 mg/kg or 0.5 mg/kg. At 10 min after induction, CRI for 90 min was initiated and comprised 25%, 50%, or 100% of the initial ketamine dose per hour or 50% of the initial doses of both ketamine and xylazine. Anesthetic regimens were compared on the basis of animal immobility, continuous surgical depth of anesthesia as determined by the absence of a pedal withdrawal reflex, and mortality. Consistent with previous studies, the response to anesthetics was highly variable. Regimens that provided the longest continuous surgical plane of anesthesia with minimal mortality were ketamine–xylazine–acepromazine (0.1 mg/kg) with CRI of 100% of the initial ketamine dose and ketamine–xylazine–acepromazine (0.5 mg/kg) with CRI of 50% of the initial ketamine and xylazine doses. In addition, heart rate and respiratory rate did not increase consistently in response to a noxious stimulus during CRI anesthesia, even when mice exhibited a positive pedal withdrawal reflex, suggesting that these parameters are unreliable indicators of anesthetic depth during ketamine–xylazine anesthesia in mice. We conclude that intraperitoneal CRI anesthesia in mice prolongs injectable anesthesia more consistently and with lower mortality than does bolus redosing. PMID:27657709

Toward translating near-infrared spectroscopy oxygen saturation data for the non-invasive prediction of spatial and temporal hemodynamics during exercise

PubMed Central

Ellwein, Laura; Samyn, Margaret M.; Danduran, Michael; Schindler-Ivens, Sheila; Liebham, Stacy; LaDisa, John F.

2016-01-01

Image-based computational fluid dynamics (CFD) studies conducted at rest have shown that atherosclerotic plaque in the thoracic aorta (TA) correlates with adverse wall shear stress (WSS), but there is a paucity of such data under elevated flow conditions. We developed a pedaling exercise protocol to obtain phase contrast magnetic resonance imaging (PC-MRI) blood flow measurements in the TA and brachiocephalic arteries during three-tiered supine pedaling at 130%, 150%, and 170% of resting heart rate (HR), and relate these measurements to noninvasive tissue oxygen saturation (StO2) acquired by near-infrared spectroscopy (NIRS) while conducting the same protocol. Local quantification of WSS indices by CFD revealed low time-averaged WSS on the outer curvature of the ascending aorta and the inner curvature of the descending aorta (dAo) that progressively increased with exercise, but that remained low on the anterior surface of brachiocephalic arteries. High oscillatory WSS observed on the inner curvature of the aorta persisted during exercise as well. Results suggest locally continuous exposure to potentially deleterious indices of WSS despite benefits of exercise. Linear relationships between flow distributions and tissue oxygen extraction calculated from StO2 were found between the left common carotid versus cerebral tissue (r2=0.96) and the dAo versus leg tissue (r2=0.87). A resulting six-step procedure is presented to use NIRS data as a surrogate for exercise PC-MRI when setting boundary conditions for future CFD studies of the TA under simulated exercise conditions. Relationships and ensemble averaged PC-MRI inflow waveforms are provided in an online repository for this purpose. PMID:27376865

Regional variations in pedal cyclist injuries in New Zealand: safety in numbers or risk in scarcity?

PubMed

Tin, Sandar Tin; Woodward, Alistair; Thornley, Simon; Ameratunga, Shanthi

2011-08-01

To assess regional variations in rates of traffic injuries to pedal cyclists resulting in death or hospital inpatient treatment, in relation to time spent cycling and time spent travelling in a car. Cycling injuries were identified from the Mortality Collection and the National Minimum Dataset. Time spent cycling and time spent travelling as a driver or passenger in a car/van/ute/SUV were computed from National Household Travel Surveys. There are 16 census regions in New Zealand, some of which were combined for this analysis to ensure an adequate sample size, resulting in eight regional groups. Analyses were undertaken for 1996-99 and 2003-07. Injury rates, per million hours spent cycling, varied widely across regions (11 to 33 injuries during 1996-99 and 12 to 78 injuries during 2003-07). The injury rate increased with decreasing per capita time spent cycling. The rate also increased with increasing per capita time spent travelling in a car. There was an inverse association between the injury rate and the ratio of time spent cycling to time spent travelling in a car. The expected number of cycling injuries increased with increasing total time spent cycling but at a decreasing rate particularly after adjusting for total time spent travelling in a car. The findings indicate a 'risk in scarcity' effect for New Zealand cyclists such that risk profiles of cyclists are likely to deteriorate if fewer people use a bicycle and more use a car. Cooperative efforts to promote cycling and its safety and to restrict car use may reverse the risk in scarcity effect. © 2011 The Authors. ANZJPH © 2011 Public Health Association of Australia.

Biomechanics and muscle coordination of human walking. Part I: introduction to concepts, power transfer, dynamics and simulations.

PubMed

Zajac, Felix E; Neptune, Richard R; Kautz, Steven A

2002-12-01

Current understanding of how muscles coordinate walking in humans is derived from analyses of body motion, ground reaction force and EMG measurements. This is Part I of a two-part review that emphasizes how muscle-driven dynamics-based simulations assist in the understanding of individual muscle function in walking, especially the causal relationships between muscle force generation and walking kinematics and kinetics. Part I reviews the strengths and limitations of Newton-Euler inverse dynamics and dynamical simulations, including the ability of each to find the contributions of individual muscles to the acceleration/deceleration of the body segments. We caution against using the concept of biarticular muscles transferring power from one joint to another to infer muscle coordination principles because energy flow among segments, even the adjacent segments associated with the joints, cannot be inferred from computation of joint powers and segmental angular velocities alone. Rather, we encourage the use of dynamical simulations to perform muscle-induced segmental acceleration and power analyses. Such analyses have shown that the exchange of segmental energy caused by the forces or accelerations induced by a muscle can be fundamentally invariant to whether the muscle is shortening, lengthening, or neither. How simulation analyses lead to understanding the coordination of seated pedaling, rather than walking, is discussed in this first part because the dynamics of pedaling are much simpler, allowing important concepts to be revealed. We elucidate how energy produced by muscles is delivered to the crank through the synergistic action of other non-energy producing muscles; specifically, that a major function performed by a muscle arises from the instantaneous segmental accelerations and redistribution of segmental energy throughout the body caused by its force generation. Part II reviews how dynamical simulations provide insight into muscle coordination of walking.

Pedaling rate is an important determinant of human oxygen uptake during exercise on the cycle ergometer.

PubMed

Formenti, Federico; Minetti, Alberto E; Borrani, Fabio

2015-09-01

Estimation of human oxygen uptake (V˙o2) during exercise is often used as an alternative when its direct measurement is not feasible. The American College of Sports Medicine (ACSM) suggests estimating human V˙o2 during exercise on a cycle ergometer through an equation that considers individual's body mass and external work rate, but not pedaling rate (PR). We hypothesized that including PR in the ACSM equation would improve its V˙o2 prediction accuracy. Ten healthy male participants' (age 19-48 years) were recruited and their steady-state V˙o2 was recorded on a cycle ergometer for 16 combinations of external work rates (0, 50, 100, and 150 W) and PR (50, 70, 90, and 110 revolutions per minute). V˙o2 was calculated by means of a new equation, and by the ACSM equation for comparison. Kinematic data were collected by means of an infrared 3-D motion analysis system in order to explore the mechanical determinants of V˙o2. Including PR in the ACSM equation improved the accuracy for prediction of sub-maximal V˙o2 during exercise (mean bias 1.9 vs. 3.3 mL O2 kg(-1) min(-1)) but it did not affect the accuracy for prediction of maximal V˙o2 (P > 0.05). Confirming the validity of this new equation, the results were replicated for data reported in the literature in 51 participants. We conclude that PR is an important determinant of human V˙o2 during cycling exercise, and it should be considered when predicting oxygen consumption. © 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

Physical fitness modulates incidental but not intentional statistical learning of simultaneous auditory sequences during concurrent physical exercise.

PubMed

Daikoku, Tatsuya; Takahashi, Yuji; Futagami, Hiroko; Tarumoto, Nagayoshi; Yasuda, Hideki

2017-02-01

In real-world auditory environments, humans are exposed to overlapping auditory information such as those made by human voices and musical instruments even during routine physical activities such as walking and cycling. The present study investigated how concurrent physical exercise affects performance of incidental and intentional learning of overlapping auditory streams, and whether physical fitness modulates the performances of learning. Participants were grouped with 11 participants with lower and higher fitness each, based on their Vo 2 max value. They were presented simultaneous auditory sequences with a distinct statistical regularity each other (i.e. statistical learning), while they were pedaling on the bike and seating on a bike at rest. In experiment 1, they were instructed to attend to one of the two sequences and ignore to the other sequence. In experiment 2, they were instructed to attend to both of the two sequences. After exposure to the sequences, learning effects were evaluated by familiarity test. In the experiment 1, performance of statistical learning of ignored sequences during concurrent pedaling could be higher in the participants with high than low physical fitness, whereas in attended sequence, there was no significant difference in performance of statistical learning between high than low physical fitness. Furthermore, there was no significant effect of physical fitness on learning while resting. In the experiment 2, the both participants with high and low physical fitness could perform intentional statistical learning of two simultaneous sequences in the both exercise and rest sessions. The improvement in physical fitness might facilitate incidental but not intentional statistical learning of simultaneous auditory sequences during concurrent physical exercise.

Effects of Knee Alignments and Toe Clip on Frontal Plane Knee Biomechanics in Cycling.

PubMed

Shen, Guangping; Zhang, Songning; Bennett, Hunter J; Martin, James C; Crouter, Scott E; Fitzhugh, Eugene C

2018-06-01

Effects of knee alignment on the internal knee abduction moment (KAM) in walking have been widely studied. The KAM is closely associated with the development of medial knee osteoarthritis. Despite the importance of knee alignment, no studies have explored its effects on knee frontal plane biomechanics during stationary cycling. The purpose of this study was to examine the effects of knee alignment and use of a toe clip on the knee frontal plane biomechanics during stationary cycling. A total of 32 participants (11 varus, 11 neutral, and 10 valgus alignment) performed five trials in each of six cycling conditions: pedaling at 80 rpm and 0.5 kg (40 Watts), 1.0 kg (78 Watts), and 1.5 kg (117 Watts) with and without a toe clip. A motion analysis system and a customized instrumented pedal were used to collect 3D kinematic and kinetic data. A 3 × 2 × 3 (group × toe clip × workload) mixed design ANOVA was used for statistical analysis (p < 0.05). There were two different knee frontal plane loading patterns, internal abduction and adduction moment, which were affected by knee alignment type. The knee adduction angle was 12.2° greater in the varus group compared to the valgus group (p = 0.001), yet no difference was found for KAM among groups. Wearing a toe clip increased the knee adduction angle by 0.95º (p = 0.005). The findings of this study indicate that stationary cycling may be a safe exercise prescription for people with knee malalignments. In addition, using a toe clip may not have any negative effects on knee joints during stationary cycling.

Cycling induced by electrical stimulation improves motor recovery in postacute hemiparetic patients: a randomized controlled trial.

PubMed

Ambrosini, Emilia; Ferrante, Simona; Pedrocchi, Alessandra; Ferrigno, Giancarlo; Molteni, Franco

2011-04-01

This study assessed whether cycling induced by functional electrical stimulation (FES) was more effective than passive cycling with placebo stimulation in promoting motor recovery and walking ability in postacute hemiparetic patients. In a double-blind, randomized, controlled trial, 35 patients were included and randomized to receive FES-induced cycling training or placebo FES cycling. The 4-week treatment consisted of 20 sessions lasting 25 minutes each. Primary outcome measures included the leg subscale of the Motricity Index and gait speed during a 50-meter walking test. Secondary outcomes were the Trunk Control Test, the Upright Motor Control Test, the mean work produced by the paretic leg, and the unbalance in mechanical work between paretic and nonparetic legs during voluntary pedaling. Participants were evaluated before training, after training, and at 3- to 5-month follow-up visits. No significant differences were found between groups at baseline. Repeated-measures ANOVA (P<0.05) revealed significant increases in Motricity Index, Trunk Control Test, Upright Motor Control Test, gait speed, and mean work of the paretic leg after training and at follow-up assessments for FES-treated patients. No outcome measures demonstrated significant improvements after training in the placebo group. Both groups showed no significant differences between assessments after training and at follow-up. A main effect favoring FES-treated patients was demonstrated by repeated-measures ANCOVA for Motricity Index (P<0.001), Trunk Control Test (P=0.001), Upright Motor Control Test (P=0.005), and pedaling unbalance (P=0.038). The study demonstrated that 20 sessions of FES cycling training significantly improved lower extremity motor functions and accelerated the recovery of overground locomotion in postacute hemiparetic patients. Improvements were maintained at follow-up.

Neuronal somata and extrasomal compartments play distinct roles during synapse formation between Lymnaea neurons.

PubMed

Xu, Fenglian; Luk, Collin C; Wiersma-Meems, Ryanne; Baehre, Kelly; Herman, Cameron; Zaidi, Wali; Wong, Noelle; Syed, Naweed I

2014-08-20

Proper synapse formation is pivotal for all nervous system functions. However, the precise mechanisms remain elusive. Moreover, compared with the neuromuscular junction, steps regulating the synaptogenic program at central cholinergic synapses remain poorly defined. In this study, we identified different roles of neuronal compartments (somal vs extrasomal) in chemical and electrical synaptogenesis. Specifically, the electrically synapsed Lymnaea pedal dorsal A cluster neurons were used to study electrical synapses, whereas chemical synaptic partners, visceral dorsal 4 (presynaptic, cholinergic), and left pedal dorsal 1 (LPeD1; postsynaptic) were explored for chemical synapse formation. Neurons were cultured in a soma-soma or soma-axon configuration and synapses explored electrophysiologically. We provide the first direct evidence that electrical synapses develop in a soma-soma, but not soma-axon (removal of soma) configuration, indicating the requirement of gene transcription regulation in the somata of both synaptic partners. In addition, the soma-soma electrical coupling was contingent upon trophic factors present in Lymnaea brain-conditioned medium. Further, we demonstrate that chemical (cholinergic) synapses between soma-soma and soma-axon pairs were indistinguishable, with both exhibiting a high degree of contact site and target cell type specificity. We also provide direct evidence that presynaptic cell contact-mediated, clustering of postsynaptic cholinergic receptors at the synaptic site requires transmitter-receptor interaction, receptor internalization, and a protein kinase C-dependent lateral migration toward the contact site. This study provides novel insights into synaptogenesis between central neurons revealing both distinct and synergistic roles of cell-cell signaling and extrinsic trophic factors in executing the synaptogenic program. Copyright © 2014 the authors 0270-6474/14/3411304-12$15.00/0.

Effects of interactive video game cycling on overweight and obese adolescent health.

PubMed

Adamo, Kristi B; Rutherford, Jane A; Goldfield, Gary S

2010-12-01

The purpose of this study was to examine the efficacy of interactive video game stationary cycling (GameBike) in comparison with stationary cycling to music on adherence, energy expenditure measures, submaximal aerobic fitness, body composition, and cardiovascular disease risk markers in overweight and obese adolescents, using a randomized controlled trial design. Thirty overweight (with at least 1 metabolic complication) or obese adolescents aged 12-17 years were stratified by gender and randomized to video game or music condition, with 4 participants (2 per group) failing to complete the twice weekly 60 min sessions of the 10-week trial. The music group had a higher rate of attendance compared with the video game group (92% vs. 86%, p < 0.05). Time spent in minutes per session at vigorous intensity (80%-100% of predicted peak heart rate) (24.9 ± 20 min vs. 13.7 ± 12.8 min, p < 0.05) and average distance (km) pedaled per session (12.5 ± 2.8 km vs. 10.2 ± 2.2 km, p < 0.05) also favoured the music group. However, both interventions produced significant improvements in submaximal indicators of aerobic fitness as measured by a graded cycle ergometer protocol. Also, when collapsed, the exercise modalities reduced body fat percentage and total cholesterol. The present study indicates that cycling to music was just as effective as stationary cycling while playing video games at improving fitness, body composition, and cholesterol profiles in overweight and obese teens, and resulted in increased attendance, vigorous intensity of physical activity, and distance pedaled. Therefore, our data support the superiority of cycling to music and indicate investing in the more expensive GameBike may not be worth the cost.

Preliminary Evaluation of the Spin and Recovery Characteristics of the Douglas XF3D-1 Airplane

NASA Technical Reports Server (NTRS)

Scher, Stanley H.

1947-01-01

A preliminary evaluation of the spin and recovery characteristics of the XF3D-1 airplane has been made, based primarily on the results of the free-spinning tunnel tests of a model which closely simulated the XF3D-1 in tail design, tail length, and mass loading. Estimates have been made of the rudder-pedal force that may be encountered in effecting recovery from a spin and of the spin recovery parachute requirements of the airplane for demonstration spins. The method of bail-out which should be used if it becomes necessary for the crew to abandon the airplane during a spin is indicated. It was indicated that the recovery characteristics of the XF3D-1 airplane in the clean condition for erect and inverted spins would be satisfactory for all loadings specified by the contractor as possible on the airplane. However, if a spin is inadvertently entered while the landing flaps are down, recovery may be slow. The slow-down brakes and the landing flaps should be retracted immediately upon the inception of a spinning condition, after which recovery from the spin should be attempted. The pedal force necessary to reverse the rudder during a spin will be within the physical capabilities of the pilot. Opening a 10-foot diameter parachute attached to the tail (laid-out-flat diameter, drag coefficient 0.7) or a 4.5-foot diameter parachute attached to the outboard wing tip will insure satisfactory spin recovery from demonstration spins. If it becomes necessary for the crew to abandon the airplane during a spin, they should leave from the outboard side of the cockpit.

Alcohol intoxication in non-motorised road trauma.

PubMed

Mitra, Biswadev; Charters, Kate E; Spencer, John C; Fitzgerald, Mark C; Cameron, Peter A

2017-02-01

To determine the proportion of non-motorised road users involved in road traffic crashes that presents to hospital intoxicated. We undertook a retrospective cohort study using data collected from the Alfred Trauma Registry. All patients presenting to an adult major trauma centre in Victoria, Australia from July 2009 to June 2014 who were involved in a road traffic crash as a non-motorised road user - pedestrians, pedal-cyclists, non-motorised scooter users, horse riders - were included. Patients who had a blood alcohol measurement were included, and intoxication was defined as a blood alcohol concentration ≥0.05 g/100 mL. There were 1323 patients included for analysis with data on presenting blood alcohol concentration. Alcohol was detected in 248 (18.7%; 95% CI: 16.7-20.9) patients, whereas 211 (15.9%; 95% CI: 14.1-18.0) were intoxicated. Among all included pedestrians, 161 (24.7%) were intoxicated; among all included pedal-cyclists, 47 (7.3%) were intoxicated. Intoxicated patients were significantly younger, and a higher proportion were males and more likely to present after hours and on public holidays (P < 0.01). Survival to hospital discharge and inpatient rehabilitation requirements were similar among intoxicated and non-intoxicated patients. Intoxication was common among non-motorised road users, and the proportion of intoxicated patients in this subgroup appears unchanged over time despite public awareness programmes. The true burden of intoxication in non-motorised road users remains unknown because of a lack of routine testing. Legislation directed at testing for intoxication of non-motorised users and introduction of penalties should be considered to improve safety of all road users. © 2016 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine.

Restoration of Hindlimb Movements after Complete Spinal Cord Injury Using Brain-Controlled Functional Electrical Stimulation.

PubMed

Knudsen, Eric B; Moxon, Karen A

2017-01-01

Single neuron and local field potential signals recorded in the primary motor cortex have been repeatedly demonstrated as viable control signals for multi-degree-of-freedom actuators. Although the primary source of these signals has been fore/upper limb motor regions, recent evidence suggests that neural adaptation underlying neuroprosthetic control is generalizable across cortex, including hindlimb sensorimotor cortex. Here, adult rats underwent a longitudinal study that included a hindlimb pedal press task in response to cues for specific durations, followed by brain machine interface (BMI) tasks in healthy rats, after rats received a complete spinal transection and after the BMI signal controls epidural stimulation (BMI-FES). Over the course of the transition from learned behavior to BMI task, fewer neurons were responsive after the cue, the proportion of neurons selective for press duration increased and these neurons carried more information. After a complete, mid-thoracic spinal lesion that completely severed both ascending and descending connections to the lower limbs, there was a reduction in task-responsive neurons followed by a reacquisition of task selectivity in recorded populations. This occurred due to a change in pattern of neuronal responses not simple changes in firing rate. Finally, during BMI-FES, additional information about the intended press duration was produced. This information was not dependent on the stimulation, which was the same for short and long duration presses during the early phase of stimulation, but instead was likely due to sensory feedback to sensorimotor cortex in response to movement along the trunk during the restored pedal press. This post-cue signal could be used as an error signal in a continuous decoder providing information about the position of the limb to optimally control a neuroprosthetic device.

Pedal peptide/orcokinin‐type neuropeptide signaling in a deuterostome: The anatomy and pharmacology of starfish myorelaxant peptide in Asterias rubens

PubMed Central

Lin, Ming; Egertová, Michaela; Zampronio, Cleidiane G.; Jones, Alexandra M.

2017-01-01

Abstract Pedal peptide (PP) and orcokinin (OK) are related neuropeptides that were discovered in protostomian invertebrates (mollusks, arthropods). However, analysis of genome/transcriptome sequence data has revealed that PP/OK‐type neuropeptides also occur in a deuterostomian phylum—the echinoderms. Furthermore, a PP/OK‐type neuropeptide (starfish myorelaxant peptide, SMP) was recently identified as a muscle relaxant in the starfish Patiria pectinifera. Here mass spectrometry was used to identify five neuropeptides (ArPPLN1a‐e) derived from the SMP precursor (PP‐like neuropeptide precursor 1; ArPPLNP1) in the starfish Asterias rubens. Analysis of the expression of ArPPLNP1 and neuropeptides derived from this precursor in A. rubens using mRNA in situ hybridization and immunohistochemistry revealed a widespread pattern of expression, with labeled cells and/or processes present in the radial nerve cords, circumoral nerve ring, digestive system (e.g., cardiac stomach) and body wall‐associated muscles (e.g., apical muscle) and appendages (e.g., tube feet and papulae). Furthermore, our data provide the first evidence that neuropeptides are present in the lateral motor nerves and in nerve processes innervating interossicular muscles. In vitro pharmacological tests with SMP (ArPPLN1b) revealed that it causes dose‐dependent relaxation of apical muscle, tube foot and cardiac stomach preparations from A. rubens. Collectively, these anatomical and pharmacological data indicate that neuropeptides derived from ArPPLNP1 act as inhibitory neuromuscular transmitters in starfish, which contrasts with the myoexcitatory actions of PP/OK‐type neuropeptides in protostomian invertebrates. Thus, the divergence of deuterostomes and protostomes may have been accompanied by an inhibitory–excitatory transition in the roles of PP/OK‐type neuropeptides as regulators of muscle activity. PMID:28880392

The oculomotor system of decapod cephalopods: eye muscles, eye muscle nerves, and the oculomotor neurons in the central nervous system.

PubMed

Budelmann, B U; Young, J Z

1993-04-29

Fourteen extraocular eye muscles are described in the decapods Loligo and Sepioteuthis, and thirteen in Sepia; they are supplied by four eye muscle nerves. The main action of most of the muscles is a linear movement of the eyeball, only three muscles produce strong rotations. The arrangement, innervation and action of the decapod eye muscles are compared with those of the seven eye muscles and seven eye muscle nerves in Octopus. The extra muscles in decapods are attached to the anterior and superior faces of the eyes. At least, the anterior muscles, and presumably also the superior muscles, are concerned with convergent eye movements for binocular vision during fixation and capture of prey by the tentacles. The remaining muscles are rather similar in the two cephalopod groups. In decapods, the anterior muscles include conjunctive muscles; these cross the midline and each presumably moves both eyes at the same time during fixation. In the squids Loligo and Sepioteuthis there is an additional superior conjunctive muscle of perhaps similar function. Some of the anterior muscles are associated with a narrow moveable plate, the trochlear cartilage; it is attached to the eyeball by trochlear membranes. Centripetal cobalt fillings showed that all four eye muscle nerves have fibres that originate from somata in the ipsilateral anterior lateral pedal lobe, which is the oculomotor centre. The somata of the individual nerves show different but overlapping distributions. Bundles of small presumably afferent fibres were seen in two of the four nerves. They do not enter the anterior lateral pedal lobe but run to the ventral magnocellular lobe; some afferent fibres enter the brachio-palliovisceral connective and run perhaps as far as the palliovisceral lobe.

Influence of maneuverability on helicopter combat effectiveness

NASA Technical Reports Server (NTRS)

Falco, M.; Smith, R.

1982-01-01

A computational procedure employing a stochastic learning method in conjunction with dynamic simulation of helicopter flight and weapon system operation was used to derive helicopter maneuvering strategies. The derived strategies maximize either survival or kill probability and are in the form of a feedback control based upon threat visual or warning system cues. Maneuverability parameters implicit in the strategy development include maximum longitudinal acceleration and deceleration, maximum sustained and transient load factor turn rate at forward speed, and maximum pedal turn rate and lateral acceleration at hover. Results are presented in terms of probability of skill for all combat initial conditions for two threat categories.

Baseline tests of the Volkswagen transporter electric delivery van

NASA Technical Reports Server (NTRS)

Soltis, R. F.; Mcbrien, E. F.; Bozek, J. M.; Gourash, F.

1978-01-01

The Volkswagen Transporter, an electric delivery van, was tested as part of an Energy Research and Development Administration (ERDA) project to characterize the state of the art of electric vehicles. The Volkswagen Transporter is a standard Volkswagen van that has been converted to an electric vehicle. It is powered by a 144-volt traction battery. A direct current (dc) chopper controller, actuated by a conventional accelerator pedal, regulates the voltage or power applied to the 16-kilowatt (21-hp) motor. The braking system uses conventional hydraulic braking in combination with an electric regenerative braking system. The Volkswagen vehicle performance test results are presented.

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

Solheim, B.A.

Three families of termites have the ability to produce a sticky secretion that envelopes and immobilizes the enemy. In the family Termitidae the secretion contains the diterpenoid hydrocarbons, kempene I and kempene II. The molecular structure of kempene II from the termite, Nasutitermes kempae, is described in detail. Another species of termite, Cubitermes umbratus, contained the diterpenoid hydrocarbon biflora-4,10-19,15-triene in the secretion and this compound is described. Studies were also conducted on the mucous secretion of the pedal gland of the marine nudibranch, Tidachiella diomedea. Tridachione, a substituted ..gamma..-pyrone, was isolated in the pure state and its molecular structure ismore » described in detail. (HLW)« less

Social facilitation in virtual reality-enhanced exercise: competitiveness moderates exercise effort of older adults.

PubMed

Anderson-Hanley, Cay; Snyder, Amanda L; Nimon, Joseph P; Arciero, Paul J

2011-01-01

This study examined the effect of virtual social facilitation and competitiveness on exercise effort in exergaming older adults. Fourteen exergaming older adults participated. Competitiveness was assessed prior to the start of exercise. Participants were trained to ride a "cybercycle;" a virtual reality-enhanced stationary bike with interactive competition. After establishing a cybercycling baseline, competitive avatars were introduced. Pedaling effort (watts) was assessed. Repeated measures ANOVA revealed a significant group (high vs low competitiveness) × time (pre- to post-avatar) interaction (F[1,12] = 13.1, P = 0.003). Virtual social facilitation increased exercise effort among more competitive exercisers. Exercise programs that match competitiveness may maximize exercise effort.

Research on Acceleration Compensation Strategy of Electric Vehicle Based on Fuzzy Control Theory

NASA Astrophysics Data System (ADS)

Zhu, Tianjun; Li, Bin; Zong, Changfu; Wei, Zhicheng

2017-09-01

Nowadays, the driving technology of electric vehicle is developing rapidly. There are many kinds of methods in driving performance control technology. The paper studies the acceleration performance of electric vehicle. Under the premise of energy management, an acceleration power compensation method by fuzzy control theory based on driver intention recognition is proposed, which can meet the driver’s subjective feelings better. It avoids the problem that the pedal opening and power output are single correspondence when the traditional vehicle accelerates. Through the simulation test, this method can significantly improve the performance of acceleration and output torque smoothly in non-emergency acceleration to ensure vehicle comfortable and stable.

The diagnosis and treatment of infections of the pedal integument.

PubMed

Miller, S J

1986-07-01

Dr. Miller's discussion of the diagnosis and management of soft tissue infections is probably one of the most important topics in this issue. We are all faced with the potential for relatively minor infections becoming serious problems. Having a sound understanding of the infectious process and treatment regimens is extremely important in our general practices. Few things can make a patient as unhappy or destroy good surgical results as quickly and easily as an infection. I recommend reading the articles suggested by Dr. Miller and add that I believe that if the infection has not responded as quickly to therapy as is expected, an infectious disease consultation should be requested.

Cycling injuries of the lower extremity.

PubMed

Wanich, Tony; Hodgkins, Christopher; Columbier, Jean-Allain; Muraski, Erika; Kennedy, John G

2007-12-01

Cycling is an increasingly popular recreational and competitive activity, and cycling-related injuries are becoming more common. Many common cycling injuries of the lower extremity are preventable. These include knee pain, patellar quadriceps tendinitis, iliotibial band syndrome, hip pain, medial tibial stress syndrome, stress fracture, compartment syndrome, numbness of the foot, and metatarsalgia. Injury is caused by a combination of inadequate preparation, inappropriate equipment, poor technique, and overuse. Nonsurgical management may include rest, nonsteroidal anti-inflammatory drugs, corticosteroid injection, ice, a reduction in training intensity, orthotics, night splints, and physical therapy. Injury prevention should be the focus, with particular attention to bicycle fit and alignment, appropriate equipment, proper rider position and pedaling mechanics, and appropriate training.

Health effects of silicon tetrachloride. Report of an urban accident

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

Kizer, K.W.; Garb, L.G.; Hine, C.H.

1984-01-01

A spill of silicon tetrachloride (SiCl4) at a chemical plant caused the evacuation of several thousand people from an industrial park; 28 persons sought medical attention. Most of the affected individuals suffered only transient eye and upper airway irritation. Six of the plant employees were later referred for detailed evaluation of possible lung injury, but no definite evidence of SiCl4-induced pulmonary dysfunction was found. Five of these workers also experienced recurrent headaches, and two complained of pedal dysesthesias after the accident. Although the temporal relationship between the exposure and onset of these symptoms is notable, no definite etiologic relationship couldmore » be established.« less

Immunohistochemical localization of FMRFamide-containing neurons and nerve fibers in the ganglia and the gonad wall of the scallop, Pecten maximus (L).

PubMed

Henry, M; Benlinmame, N; Belhsen, O K; Jule, Y; Mathieu, M

1995-02-01

The Phe-Met-Arg-Phe NH2 (FMRFamide)-like immunoreactivity was detected in neurons of the cerebro-pedal and visceral ganglia of the scallop Pecten maximus using immunohistochemical techniques. FMRFamide-like immunoreactivity was also found in nerve fibers localized in the connective tissue and the epithelial wall of the gonad. Electron microscopy study carried out on the gonads indicates the existence of numerous nerve fibers crossing the connective tissue; nerve terminals apposed to highly secretory cells were seen in the gonad wall. All in all, the present immunohistochemical and electron microscopic data suggest that FMRFamide might play an unusual secretagogue role in the gonad wall.

[Ultrasound dissection in laparoscopic cholecystectomy].

PubMed

Horstmann, R; Kern, M; Joosten, U; Hohlbach, G

1993-01-01

An ultrasound dissector especially developed for laparoscopic surgery was used during laparoscopic cholecystectomy on 34 patients. The ultrasound power, the volume of suction and irrigation could be determined individually at the generator and activated during the operation with a foot pedal. With the dissector it was possible to fragmentate, emulgate and aspirate simultaneously fat tissue as well as infected edematous structures. The cystic artery and cystic duct, small vessels, lymphatic and connective tissue were not damaged. Therefore this system seems to be excellent for the preparation of Calot's trigonum and blunt dissection of the gallbladder out of its bed, particularly in fatty, acute or chronic infected tissue. No complications were observed within the peri- and postoperative period.

Social facilitation in virtual reality-enhanced exercise: competitiveness moderates exercise effort of older adults

PubMed Central

Anderson-Hanley, Cay; Snyder, Amanda L; Nimon, Joseph P; Arciero, Paul J

2011-01-01

This study examined the effect of virtual social facilitation and competitiveness on exercise effort in exergaming older adults. Fourteen exergaming older adults participated. Competitiveness was assessed prior to the start of exercise. Participants were trained to ride a “cybercycle;” a virtual reality-enhanced stationary bike with interactive competition. After establishing a cybercycling baseline, competitive avatars were introduced. Pedaling effort (watts) was assessed. Repeated measures ANOVA revealed a significant group (high vs low competitiveness) × time (pre- to post-avatar) interaction (F[1,12] = 13.1, P = 0.003). Virtual social facilitation increased exercise effort among more competitive exercisers. Exercise programs that match competitiveness may maximize exercise effort. PMID:22087067

Identification of Prevotella in pedal osteomyelitis of a diabetic patient.

PubMed

Dominiak, Barbara J; Oxberry, William; Chen, Patrick C

2003-01-01

Osteomyelitis in a diabetic patient with a nonhealing foot ulcer, multiple medical conditions, and recurrent hospitalization for antibiotic therapy was found to be associated with gram-negative bacteria Prevotella melanginoganica and Prevotella melaninoganica hemagglutinating variant. Those organisms were identified due to the morphologically distinct features in electron microscopy and sequencing of the genes after Polymerase chain reaction amplification from the pathological material. The bacteria invaded the bone and resided in osteocyte, osteoblast, and endothelial cells. The bacteria are usually associated with periodontal plaques, causing inflammation and destruction of gingival tissue and resorption of the alveolar bone. This is the first ultrastructural and molecular study of a diabetic bone lesion with anaerobic bacterial infection.

A Third Arm for the Surgeon

NASA Technical Reports Server (NTRS)

1994-01-01

In laparoscopic surgery, tiny incisions are made in the patient's body and a laparoscope (an optical tube with a camera at the end) is inserted. The camera's image is projected onto two video screens, whose views guide the surgeon through the procedure. AESOP, a medical robot developed by Computer Motion, Inc. with NASA assistance, eliminates the need for a human assistant to operate the camera. The surgeon uses a foot pedal control to move the device, allowing him to use both hands during the surgery. Miscommunication is avoided; AESOP's movement is smooth and steady, and the memory vision is invaluable. Operations can be completed more quickly, and the patient spends less time under anesthesia. AESOP has been approved by the FDA.

Coordination of locomotor and cardiorespiratory networks of Lymnaea stagnalis by a pair of identified interneurones.

PubMed

Syed, N I; Winlow, W

1991-07-01

1. The morphology and electrophysiology of a newly identified bilateral pair of interneurones in the central nervous system of the pulmonate pond snail Lymnaea stagnalis is described. 2. These interneurones, identified as left and right pedal dorsal 11 (L/RPeD11), are electrically coupled to each other as well as to a large number of foot and body wall motoneurones, forming a fast-acting neural network which coordinates the activities of foot and body wall muscles. 3. The left and right sides of the body wall of Lymnaea are innervated by left and right cerebral A cluster neurones. Although these motoneurones have only ipsilateral projections, they are indirectly electrically coupled to their contralateral homologues via their connections with L/RPeD11. Similarly, the activities of left and right pedal G cluster neurones, which are known to be involved in locomotion, are also coordinated by L/RPeD11. 4. Selective ablation of both neurones PeD11 results in the loss of coordination between the bilateral cerebral A clusters. 5. Interneurones L/RPeD11 are multifunctional. In addition to coordinating motoneuronal activity, they make chemical excitatory connections with heart motoneurones. They also synapse upon respiratory motoneurones, hyperpolarizing those involved in pneumostome opening (expiration) and depolarizing those involved in pneumostome closure (inspiration). 6. An identified respiratory interneurone involved in pneumostome closure (visceral dorsal 4) inhibits L/RPeD11 together with all their electrically coupled follower cells. 7. Both L/RPeD11 have strong excitatory effects on another pair of electrically coupled neurones, visceral dorsal 1 and right parietal dorsal 2, which have previously been shown to be sensitive to changes in the partial pressure of environmental oxygen (PO2). 8. Although L/RPeD11 participate in whole-body withdrawal responses, electrical stimulation applied directly to these neurones was not sufficient to induce this behaviour.

Functional characterization of a second pedal peptide/orcokinin‐type neuropeptide signaling system in the starfish Asterias rubens

PubMed Central

Lin, Ming; Egertová, Michaela; Zampronio, Cleidiane G.; Jones, Alexandra M.

2017-01-01

Abstract Molluscan pedal peptides (PPs) and arthropod orcokinins (OKs) are prototypes of a family of neuropeptides that have been identified in several phyla. Recently, starfish myorelaxant peptide (SMP) was identified as a PP/OK‐type neuropeptide in the starfish Patiria pectinifera (phylum Echinodermata). Furthermore, analysis of transcriptome sequence data from the starfish Asterias rubens revealed two PP/OK‐type precursors: an SMP‐type precursor (A. rubens PP‐like neuropeptide precursor 1; ArPPLNP1) and a second precursor (ArPPLNP2). We reported previously a detailed analysis of ArPPLNP1 expression in A. rubens and here we report the first functional characterization ArPPLNP2‐derived neuropeptides. Sequencing of a cDNA encoding ArPPLNP2 revealed that it comprises eleven related neuropeptides (ArPPLN2a‐k), the structures of several of which were confirmed using mass spectrometry. Analysis of the expression of ArPPLNP2 and neuropeptides derived from this precursor using mRNA in situ hybridization and immunohistochemistry revealed a widespread distribution, including expression in radial nerve cords, circumoral nerve ring, digestive system, tube feet and innervation of interossicular muscles. In vitro pharmacology revealed that the ArPPLNP2‐derived neuropeptide ArPPLN2h has no effect on the contractility of tube feet or the body wall‐associated apical muscle, contrasting with the relaxing effect of ArPPLN1b (ArSMP) on these preparations. ArPPLN2h does, however, cause dose‐dependent relaxation of cardiac stomach preparations, with greater potency/efficacy than ArPPLN1b and with similar potency/efficacy to the SALMFamide neuropeptide S2. In conclusion, there are similarities in the expression patterns of ArPPLNP1 and ArPPLNP2 but our data also indicate specialization in the roles of neuropeptides derived from these two PP/OK‐type precursors in starfish. PMID:29218721

Functional characterization of a second pedal peptide/orcokinin-type neuropeptide signaling system in the starfish Asterias rubens.

PubMed

Lin, Ming; Egertová, Michaela; Zampronio, Cleidiane G; Jones, Alexandra M; Elphick, Maurice R

2018-04-01

Molluscan pedal peptides (PPs) and arthropod orcokinins (OKs) are prototypes of a family of neuropeptides that have been identified in several phyla. Recently, starfish myorelaxant peptide (SMP) was identified as a PP/OK-type neuropeptide in the starfish Patiria pectinifera (phylum Echinodermata). Furthermore, analysis of transcriptome sequence data from the starfish Asterias rubens revealed two PP/OK-type precursors: an SMP-type precursor (A. rubens PP-like neuropeptide precursor 1; ArPPLNP1) and a second precursor (ArPPLNP2). We reported previously a detailed analysis of ArPPLNP1 expression in A. rubens and here we report the first functional characterization ArPPLNP2-derived neuropeptides. Sequencing of a cDNA encoding ArPPLNP2 revealed that it comprises eleven related neuropeptides (ArPPLN2a-k), the structures of several of which were confirmed using mass spectrometry. Analysis of the expression of ArPPLNP2 and neuropeptides derived from this precursor using mRNA in situ hybridization and immunohistochemistry revealed a widespread distribution, including expression in radial nerve cords, circumoral nerve ring, digestive system, tube feet and innervation of interossicular muscles. In vitro pharmacology revealed that the ArPPLNP2-derived neuropeptide ArPPLN2h has no effect on the contractility of tube feet or the body wall-associated apical muscle, contrasting with the relaxing effect of ArPPLN1b (ArSMP) on these preparations. ArPPLN2h does, however, cause dose-dependent relaxation of cardiac stomach preparations, with greater potency/efficacy than ArPPLN1b and with similar potency/efficacy to the SALMFamide neuropeptide S2. In conclusion, there are similarities in the expression patterns of ArPPLNP1 and ArPPLNP2 but our data also indicate specialization in the roles of neuropeptides derived from these two PP/OK-type precursors in starfish. © 2017 The Authors The Journal of Comparative Neurology Published by Wiley Periodicals, Inc.

Pedal peptide/orcokinin-type neuropeptide signaling in a deuterostome: The anatomy and pharmacology of starfish myorelaxant peptide in Asterias rubens.

PubMed

Lin, Ming; Egertová, Michaela; Zampronio, Cleidiane G; Jones, Alexandra M; Elphick, Maurice R

2017-12-15

Pedal peptide (PP) and orcokinin (OK) are related neuropeptides that were discovered in protostomian invertebrates (mollusks, arthropods). However, analysis of genome/transcriptome sequence data has revealed that PP/OK-type neuropeptides also occur in a deuterostomian phylum-the echinoderms. Furthermore, a PP/OK-type neuropeptide (starfish myorelaxant peptide, SMP) was recently identified as a muscle relaxant in the starfish Patiria pectinifera. Here mass spectrometry was used to identify five neuropeptides (ArPPLN1a-e) derived from the SMP precursor (PP-like neuropeptide precursor 1; ArPPLNP1) in the starfish Asterias rubens. Analysis of the expression of ArPPLNP1 and neuropeptides derived from this precursor in A. rubens using mRNA in situ hybridization and immunohistochemistry revealed a widespread pattern of expression, with labeled cells and/or processes present in the radial nerve cords, circumoral nerve ring, digestive system (e.g., cardiac stomach) and body wall-associated muscles (e.g., apical muscle) and appendages (e.g., tube feet and papulae). Furthermore, our data provide the first evidence that neuropeptides are present in the lateral motor nerves and in nerve processes innervating interossicular muscles. In vitro pharmacological tests with SMP (ArPPLN1b) revealed that it causes dose-dependent relaxation of apical muscle, tube foot and cardiac stomach preparations from A. rubens. Collectively, these anatomical and pharmacological data indicate that neuropeptides derived from ArPPLNP1 act as inhibitory neuromuscular transmitters in starfish, which contrasts with the myoexcitatory actions of PP/OK-type neuropeptides in protostomian invertebrates. Thus, the divergence of deuterostomes and protostomes may have been accompanied by an inhibitory-excitatory transition in the roles of PP/OK-type neuropeptides as regulators of muscle activity. © 2017 The Authors The Journal of Comparative Neurology Published by Wiley Periodicals, Inc.

High-Speed Cycling Intervention Improves Rate-Dependent Mobility in Older Adults

PubMed Central

Bellumori, Maria; Uygur, Mehmet; Knight, Christopher A.

2016-01-01

PURPOSE The aim was to determine the feasibility of a six-week speed-based exercise program that could be used to initiate new exercise behaviors and improve rapid movement in older adults approaching frailty. METHODS The intervention group included 14 older adults (3 males, 11 females, mean (SD) age: 70 (7.6) years, height: 1.6 (.11) m, mass: 76.8 (12.0) kg, BMI: 27.7(4.7)). The control group included 12 older adults (6 males, 6 females, mean (SD) age: 69.2 (6.9) years, height: 1.7 (.09) m, mass: 78.2 (10.9) kg, BMI: 25.3 (2.7)). Subjects included active older adults, including regular exercisers, but none were engaged in sports or exercises with an emphasis on speed (e.g. cycling spin classes or tennis). Stationary recumbent cycling was selected to minimize fall risk and low pedaling resistance reduced musculoskeletal and cardiovascular load. Two weekly 30-minute exercise sessions consisted of interval training in which subjects pedaled at preferred cadence and performed ten 20-s fast cadence intervals separated by 40-s of active recovery at preferred cadence. RESULTS Significant Group by Time interactions (p<.05) supported a 2-s improvement in the timed up and go test and a 34% improvement in rapid isometric knee extension contractions in the exercise group but not in controls. Central neural adaptations are suggested because this lower extremity exercise program also elicited significant improvements in the untrained upper extremities of the exercise group (elbow extension RFD-SF and 9-Hole Peg Test, p<.05). CONCLUSION These results demonstrate that a relatively low dose of speed-based exercise can improve neuromuscular function and tests of mobility in older adults. Such a program serves as a sensible precursor to subsequent, more vigorous training or as an adjunct to a program where a velocity emphasis is lacking. PMID:27501360

Pediatric endurance and limb strengthening for children with cerebral palsy (PEDALS) – a randomized controlled trial protocol for a stationary cycling intervention

PubMed Central

Fowler, Eileen G; Knutson, Loretta M; DeMuth, Sharon K; Sugi, Mia; Siebert, Kara; Simms, Victoria; Azen, Stanley P; Winstein, Carolee J

2007-01-01

Background In the past, effortful exercises were considered inappropriate for children with spastic cerebral palsy (CP) due to concern that they would escalate abnormalities including spasticity and abnormal movement patterns. Current scientific evidence indicates that these concerns were unfounded and that therapeutic interventions focused on muscle strengthening can lead to improved functional ability. However, few studies have examined the potential benefits of cardiorespiratory fitness exercises in this patient population. Methods/design The rationale and design of a randomized controlled trial examining the effects of a stationary cycling intervention for children with CP are outlined here. Sixty children with spastic diplegic CP between the ages of 7 and 18 years and Gross Motor Function Classification System (GMFCS) levels of I, II, or III will be recruited for this study. Participants will be randomly assigned to either an intervention (cycling) or a control (no cycling) group. The cycling intervention will be divided into strengthening and cardiorespiratory endurance exercise phases. During the strengthening phase, the resistance to lower extremity cycling will be progressively increased using a uniquely designed limb-loaded mechanism. The cardiorespiratory endurance phase will focus on increasing the intensity and duration of cycling. Children will be encouraged to exercise within a target heart rate (HR) range (70 – 80% maximum HR). Thirty sessions will take place over a 10–12 week period. All children will be evaluated before (baseline) and after (follow-up) the intervention period. Primary outcome measures are: knee joint extensor and flexor moments, or torque; the Gross Motor Function Measure (GMFM); the 600 Yard Walk-Run test and the Thirty-Second Walk test (30 sec WT). Discussion This paper presents the rationale, design and protocol for Pediatric Endurance and Limb Strengthening (PEDALS); a Phase I randomized controlled trial evaluating the efficacy of a stationary cycling intervention for children with spastic diplegic cerebral palsy. PMID:17374171

Evaluation of antiallergic and anti-anaphylactic activity of ethanolic extract of Sanseveiria trifasciata leaves (EEST) in rodents.

PubMed

Andhare, Rohan N; Raut, Mayuresh K; Naik, Suresh R

2012-08-01

The leaves and rhizomes of Sansevieria trifasciata are used in folk medicine for treating bronchitis, asthma, cough, snake bite and insect bite etc. The ethanolic extract elicited analgesic, anti-inflammatory and antipyretic activity. Hence, it was decided to study the antiallergic activity of ethanolic extract of S. trifasciata (EEST) on various animal models as well as in vitro conditions, and also to understand possible mechanism of action. Ethanolic extract of S. trifasciata leaves (EEST) were prepared by cold maceration followed by concentration and evaporation under reduced pressure on a rotary evaporator to obtain semisolid mass. The various phytoconstituents were analyzed. The acute toxicity study of EEST was carried out in mice. The antiallergic and anaphylactic activities were evaluated using animal models viz. milk induced eosinophilia and leukocytosis, compound 48/80 induced mast cell degranulation, active and passive cutaneous anaphylaxis and histamine induced pedal edema. In addition, EEST effect on Shultz-Dale reaction in sensitized guinea pig ileum in ex vivo and antioxidant activity by free radical scavenging by DPPH method (in vitro) were also studied. EEST treatment at 100mg/kg and 200mg/kg p.o inhibited (a) milk-induced increased eosinophilia, leukocytosis, monocytes and neutrophils. (b) Prevented passive cutaneous and active anaphylactoid reactions. (c) Prevented compound 48/80 induced degranulation of sensitized mesenteric mast cells. (d) Inhibited histamine induced pedal edema formation significantly. EEST pretreatment inhibited Shultz-Dale reaction in guinea pig ileum and also elicited potent antioxidant activity. Experimental findings demonstrate promising antiallergic and anti-anaphylactic activity of EEST and also elicited potent antioxidant activity. The antiallergic and anti-anphylactic activity might be due to inhibition of release of chemical mediators from mast cells largely by phytoconstituents like steroidal saponins, triterpenoids and flavonoids present in EEST. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Emergency department visits with facial fractures among children and adolescents: an analysis of profile and predictors of causes of injuries.

PubMed

Allareddy, Veerasathpurush; Itty, Abraham; Maiorini, Elyse; Lee, Min Kyeong; Rampa, Sankeerth; Allareddy, Veerajalandhar; Nalliah, Romesh P

2014-09-01

The objectives of this study were to provide nationally representative estimates of hospital-based emergency department (ED) visits for facial fractures in children and adolescents, examine the burden associated with such visits, identify common types of facial fracture, and examine the role of patient-related demographic factors on the causes of facial fractures. The Nationwide Emergency Department Sample for 2008 to 2010 was used. All ED visits with a diagnosis of facial fractures in those no older than 21 years were selected. Demographic characteristics, types of facial fracture, causes of injuries, and hospital charges were examined. During the study period, 336,124 ED visits were for facial fractures in those no older than 21 years. Late adolescents (18 to 21 yr old) and middle adolescents (15 to 17 yr old) comprised 45.6% and 26.6% of all ED visits, respectively. Male patients comprised 74.7% of ED visits. The most common facial fractures were those of the nasal bones and mandible. Younger children were more likely to have falls, pedal cycle accidents, pedestrian accidents, and transport accidents, whereas older groups were more likely to have firearm injuries, motor vehicle traffic accidents, and assaults (P < .05). Female patients were more likely to have falls, motor vehicle traffic accidents, and transport accidents, whereas male patients were more likely to have firearm injuries, pedal cycle accidents, and assaults (P < .05). Those residing at low annual income household levels were at a high risk for having firearm injuries, motor vehicle traffic accidents, and transport accidents (P < .05). Late adolescents, middle adolescents, and male patients comprise a significant proportion of these ED visits. Age, gender, and household income levels are significantly associated with the causes of facial fracture injuries. Copyright © 2014 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Recovery of function, peripheral sensitization and sensory neurone activation by novel pathways following axonal injury in Aplysia californica.

PubMed

Dulin, M F; Steffensen, I; Morris, C E; Walters, E T

1995-10-01

Recovery of behavioural and sensory function was examined following unilateral pedal nerve crush in Aplysia californica. Nerve crush that transected all axons connecting the tail to the central nervous system (CNS) eliminated the ipsilateral tail-evoked siphon reflex, whose sensory input travels in the crushed tail nerve (p9). The first reliable signs of recovery of this reflex were observed within 1 week, and most animals displayed tail-evoked siphon responses within 2 weeks. Wide-dynamic-range mechanosensory neurons with somata in the ventrocaudal (VC) cluster of the ipsilateral pleural ganglion exhibited a few receptive fields (RFs) on the tail 3 weeks after unilateral pedal nerve crush, indicating that the RFs had either regenerated or been reconnected to the central somata. These RFs were smaller and sensitized compared with corresponding RFs on the contralateral, uncrushed side. Centrally conducted axon responses of VC sensory neurones to electrical stimulation distal to the nerve crush site did not reappear until at least 10 days after the crush. Because the crush site was much closer to the CNS than to the tail, the failure of axon responses to be restored earlier than the behavioural responses indicates that early stages of reflex recovery are not due to regeneration of VC sensory neurone axons into the tail. Following nerve crush, VC sensory neurones often could be activated by stimulating central connectives or peripheral nerves that do not normally contain the sensory neurone's axons. These results suggest that recovery of behavioral function after nerve injury involves complex mechanisms, including regenerative growth of axotomized VC sensory neurones, sensitization of regenerating RFs and sprouting of VC sensory neurone fibres within the CNS. Furthermore, the rapidity of behavioural recovery indicates that its initial phases are mediated by additional mechanisms, perhaps centripetal regeneration of unidentified sensory neurones having peripheral somata, or transient reconnection of proximal and distal stumps of axotomized VC cells.

Case Studies in Physiology: Maximal oxygen consumption and performance in a centenarian cyclist.

PubMed

Billat, Véronique; Dhonneur, Gilles; Mille-Hamard, Laurence; Le Moyec, Laurence; Momken, Iman; Launay, Thierry; Koralsztein, Jean Pierre; Besse, Sophie

2017-03-01

The purpose of this study was to examine the physiological characteristics of an elite centenarian cyclist who, at 101 yr old, established the 1-h cycling record for individuals ≥100 yr old (24.25 km) and to determine the physiological factors associated with his performance improvement 2 yr later at 103 yr old (26.92 km; +11%). Before each record, he performed an incremental test on a cycling ergometer. For 2 yr, he trained 5,000 km/yr with a polarized training that involved cycling 80% of mileage at "light" rate of perceived exertion (RPE) ≤12 and 20% at "hard" RPE ≥15 at a cadence between 50 and 70 rpm. His body weight and lean body mass did not change, while his maximal oxygen consumption (V̇o 2max ) increased (31-35 ml·kg -1 ·min -1 ; +13%). Peak power output increased from 90 to 125 W (+39%), mainly because of increasing the maximal pedaling frequency (69-90 rpm; +30%). Maximal heart rate did not change (134-137 beats/min) in contrast to the maximal ventilation (57-70 l/min, +23%), increasing with both the respiratory frequency (38-41 cycles/min; +8%) and the tidal volume (1.5-1.7 liters; +13%). Respiratory exchange ratio increased (1.03-1.14) to the same extent as tolerance to V̇co 2 In conclusion, it is possible to increase performance and V̇o 2max with polarized training focusing on a high pedaling cadence even after turning 100 yr old. NEW & NOTEWORTHY This study shows, for the first time, that maximal oxygen consumption (+13%) and performance (+11%) can still be increased between 101 and 103 yr old with 2 yr of training and that a centenarian is able, at 103 yr old, to cover 26.9 km/h in 1 h. Copyright © 2017 the American Physiological Society.

Changing the way we work: elevating energy expenditure with workstation alternatives.

PubMed

Tudor-Locke, C; Schuna, J M; Frensham, L J; Proenca, M

2014-06-01

Emerging evidence supports the feasibility of raising daily energy expenditure (EE) by replacing office work-related sedentary behavior with low-intensity non-exercise physical activity (PA) via workstation alternatives to the traditional office chair and desktop computer-based combinations. The purpose of this review article is to introduce a simple taxonomy to facilitate classification and study of workstation alternatives, catalog the diversity of research undertaken to date related to energy balance, and present and summarize the gaps and opportunities for a research agenda for workstation alternatives moving forward. A PubMed search elicited 57 English language articles published since 2000; additional articles were identified by reviewing reference sections and contacting authors. Selection criteria ultimately focused on use of workstation alternatives during simulated or real work tasks. The EE of sitting on a stability ball or using sit-stand/standing desks is comparable to the traditional seated condition (≅1.2 kcal min(-1)). The treadmill and pedal desks (active workstation alternatives) offer the greatest promise in terms of EE (≅2-4 kcal min(-1)). Sitting on a stability ball or using sit-stand/standing desks does not impair task performance relative to the traditional seated condition. Some evidence of typing impairment is inconsistently reported with active workstation alternatives; the finer motor skills required for mouse-related tasks may be more affected. Little is known about learning or adaptation with practice. Users are generally accepting of workstation alternatives; however, there is evidence of less than optimal use. Active workstations (that is, treadmill desks and pedal desks) in particular represent a potential strategy for mitigating the diminished EE inherent to contemporary office-based workplaces, but only if they are scalable. The science supporting active workstations is young and heterogeneous; however, this means that there are many knowledge gaps and opportunities for research, including those focused on implementation issues related to optimizing both employers' and workers' uptake.

Matching visual and nonvisual signals: evidence for a mechanism to discount optic flow during locomotion

NASA Astrophysics Data System (ADS)

Thurrell, Adrian; Pelah, Adar

2005-03-01

We report on recent experiments to investigate the Arthrovisual Locomotor Effect (ALE), a mechanism based on non-visual signals postulated to discount or remove the self-generated visual motion signals during locomotion. It is shown that perceptual matches made by standing subjects to a constant motion optic flow stimulus that is viewed while walking on a treadmill are linearly reduced by walking speed, a measure of the reported ALE. The degree of reduction in perceived speed depends on the similarity of the motor activity to natural locomotion, thus for the four activities tested, ALE strength is ranked as follows: Walking > Cycling > Hand Pedalling > Finger Tapping = 0. Other variations and important controls for the ALE are described.

Experimental investigation of disc brakes for formula Bharat

NASA Astrophysics Data System (ADS)

Misra, Sheelam; Chandra, Sharad; Bagwadi, Ashutosh

2018-05-01

we have made the brake assembly for Formula Student India in which we gathered the information about the force distribution in Master Cylinder, Assembly of Master Cylinder, Disc Brakes, Pedal Assembly has been gathered from various sources in which we come to know about that Vertical Master Cylinder is much better than the Horizontal Master Cylinder because of which we are able to reduce the weight of the Formula Student Car which ultimately affects the performance of the car. In other words, we have considered the various environmental conditions in which this braking system. The dimensions for the Disc Brake rotor is considered according to the space constraints and the material is finalized according to the hunch of calculations and the environmental conditions.

STS-37 crewmembers move CETA electrical cart along rail in JSC's WETF pool

NASA Image and Video Library

1989-12-06

STS-37 Atlantis, Orbiter Vehicle (OV) 104, Mission Specialist (MS) Jerry L. Ross generates electrical power using hand pedals to move crew and equipment translation aid (CETA) cart along a rail during underwater session in JSC's Weightless Environment Training Facility (WETF) Bldg 29. Wearing an extravehicular mobility unit (EMU), Ross operates CETA electrical cart as MS Jerome Apt holds onto the back of the cart. The two crewmembers are practicing a extravehicular activity (EVA) spacewalk they will perform in OV-104's payload bay during STS-37. CETA is a type of railroad hand cart planned as a spacewalker's transportation system along the truss of Space Station Freedom (SSF). SCUBA divers monitor astronauts' underwater activity.

Design of a symmetry controller for cycling induced by electrical stimulation: preliminary results on post-acute stroke patients.

PubMed

Ambrosini, Emilia; Ferrante, Simona; Schauer, Thomas; Ferrigno, Giancarlo; Molteni, Franco; Pedrocchi, Alessandra

2010-08-01

This study deals with the design of a controller for cycling induced by functional electrical stimulation. The controller will be exploitable in the rehabilitation of hemiparetic patients who need to recover motor symmetry. It uses the pulse width as the control variable in the stimulation of the two legs in order to nullify the unbalance between the torques produced at the two crank arms. It was validated by means of isokinetic trials performed both by healthy subjects and stroke patients. The results showed that the controller was able to reach, and then maintain, a symmetrical pedaling. In the future, the controller will be validated on a larger number of stroke patients.

Liquid Silicone to Mitigate Plantar Pedal Pressure: A Literature Review

PubMed Central

Bowling, Frank L.; Metcalfe, Stuart A.; Wu, Stephanie; Boulton, Andrew J. M.; Armstrong, David G.

2010-01-01

Disruption of the body’s plantar fat pad can occur as a result of one of three mechanisms: simple fat pad atrophy associated with age-related degeneration, steroid use, or collagen vascular disease. Actual or relative displacement in to the underlying osseous prominences may be seen in association with structural deformity of the foot. Disease states such as diabetes may alter the normal structural integrity of soft tissues through nonenzymatic glycation leading to increased stiffness and thus reduced attenuating capacity. Fat pad atrophy, regardless of the cause, is often associated with substantial emotional, physical, productivity, and financial losses. In situations where the patient is sensate, the resultant skin on bone situation is extremely painful, especially when walking. PMID:20663447

The screw propeller

NASA Astrophysics Data System (ADS)

Larrabee, E. E.

1980-07-01

Marine and air screw propellers are considered in terms of theoretical hydrodynamics as developed by Joukowsky, Prandtl, and Betz. Attention is given to the flow around wings of finite span where spanwise flow exists and where lift and the bound vorticity must all go smoothly to zero at the wing tips. The concept of a trailing vortex sheet made up of infinitesimal line vortexes roughly aligned with the direction of flight is discussed in this regard. Also considered is induced velocity, which tends to convect the sheet downward at every stage in the roll-up process, the vortex theory of propellers and the Betz-Prandtl circulation distribution. The performance of the Gossamer Albatross and of a pedal-driven biplane called the Chrysalis are also discussed.

Recreational mountain biking injuries.

PubMed

Aitken, S A; Biant, L C; Court-Brown, Charles M

2011-04-01

Mountain biking is increasing in popularity worldwide. The injury patterns associated with elite level and competitive mountain biking are known. This study analysed the incidence, spectrum and risk factors for injuries sustained during recreational mountain biking. The injury rate was 1.54 injuries per 1000 biker exposures. Men were more commonly injured than women, with those aged 30-39 years at highest risk. The commonest types of injury were wounding, skeletal fracture and musculoskeletal soft tissue injury. Joint dislocations occurred more commonly in older mountain bikers. The limbs were more commonly injured than the axial skeleton. The highest hospital admission rates were observed with head, neck and torso injuries. Protective body armour, clip-in pedals and the use of a full-suspension bicycle may confer a protective effect.

Barra da Tijuca, Rio de Janeiro, from Space

NASA Image and Video Library

2017-12-08

While gymnasts leap, cyclists pedal and divers twirl for Olympic gold in Rio de Janeiro, Brazil, several NASA Earth Observing satellites catch glimpses of the city and its surroundings from space. This image shows how Rio Olympic Park appeared to the Operational Land Imager (OLI), a sensor on Landsat 8, last September as the city prepared for the 2016 Summer Olympic Games. Image credit: Landsat 8/NASA Earth Observatory NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Dimensions of the foot muscles in the lowland gorilla.

PubMed

Oishi, Motoharu; Ogihara, Naomichi; Endo, Hideki; Komiya, Teruyuki; Kawada, Shin-Ichiro; Tomiyama, Tae; Sugiura, Yosuke; Ichihara, Nobutsune; Asari, Masao

2009-06-01

We dissected the hindlimb of a female western lowland gorilla and determined the muscle dimensions (mass, fascicle length, and physiological cross-sectional area: PCSA). Comparisons of the muscle parameters of the measured gorilla with corresponding reported human data demonstrated that the triceps surae muscles were larger and had more capacity to generate force than the other muscle groups in both species, but this tendency was more prominent in the human, probably as an adaptation to strong toe-off during bipedal walking. On the other hand, PCSAs of the extrinsic pedal digital flexors and digiti minimi muscles were larger in the western lowland gorilla, suggesting that the foot, particularly the fifth toe, has a relatively high grasping capability in the lowland gorilla.

Traumatic Laceration of the Cisterna Chyli Treated by Lymphangiography and Percutaneous Embolization

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

Allison, Stephen, E-mail: sallison@uw.edu; Rainey, Matthew, E-mail: mrainey4@uw.edu; Aarabi, Shahram, E-mail: shahram@uw.edu

Lymphangiography and percutaneous embolization has been described for the treatment of thoracic duct injury, usually occurring in the postsurgical period. We report a case of a traumatic gunshot-induced massive chylothorax. Inguinal lymphangiogram was performed demonstrating the site of injury at the cisterna chyli. The cisterna chyli was successfully accessed via a percutaneous approach, and embolization was performed. Chylothorax immediately resolved after two rounds of embolization. Although lymphangiography has been traditionally challenging and cumbersome, because of the need for pedal lymph access, the recent use of inguinal lymphangiography has made this technique more practical. Techniques used for embolization of the thoracicmore » duct may be applied to the cisterna chyli, which is much more challenging to treat surgically.« less

An Adult with Polyneuropathy and Hypogonadism due to Poems Syndrome.

PubMed

Zaidi, Saba; Sattar, Sidra; Asumal, Khealani Bhojo

2017-10-01

POEMS (acronym for polyneuropathy, organomegaly, endocrinopathy, M protein myeloma and skin changes), is a rare disease which occurs in the setting of plasma cell dyscrasias. We describe a case of an adult lady who presented with gradual onset weakness of all four limbs and multisystem involvement characterized by pedal edema, ascites, hyperpigmentation and hypogonadism. Nerve conduction study showed severe sensorimotor polyneuropathy. Serum immunofixation showed lambda light chain restricted monoclonal gammopathy. Bone marrow biopsy consistent with plasma cell dyscrasia. Hormonal assay showed decreased FSH, LH and estradiol levels which led us to diagnosis of hypogonadotrophic hypogonadism. The patient responded well to combination therapy of thalidomide, melphalan and dexamethasone. Eight months after the therapy, she noted decreased paresthesias and increased strength. She had reduced edema and ascites.

Normal pedal pulses in a popliteal artery thrombosis after a trampoline-associated knee dislocation: a case report.

PubMed

Harb, Z; Harb, A; Kammoona, Ishan; Huber, C

2011-04-01

In lower extremity trauma, it is routine to check the neurovascular status of the affected limb. Failure to recognise a vascular injury can have catastrophic consequences for the patient. The frequent observation of the distal pulses at regular intervals after a traumatic knee dislocation is absolutely mandatory for the early recognition and management of popliteal artery thrombosis. A limb-threatening complication of popliteal artery thrombosis occurring in association with a palpable dorsalis pedis pulse after a trampoline-related knee dislocation is reported here to emphasise some important teaching points. These lessons are a learning tool to help in the early recognition of the potential complications associated with such injuries and thus minimise their occurrence.

Simulated parallel annealing within a neighborhood for optimization of biomechanical systems.

PubMed

Higginson, J S; Neptune, R R; Anderson, F C

2005-09-01

Optimization problems for biomechanical systems have become extremely complex. Simulated annealing (SA) algorithms have performed well in a variety of test problems and biomechanical applications; however, despite advances in computer speed, convergence to optimal solutions for systems of even moderate complexity has remained prohibitive. The objective of this study was to develop a portable parallel version of a SA algorithm for solving optimization problems in biomechanics. The algorithm for simulated parallel annealing within a neighborhood (SPAN) was designed to minimize interprocessor communication time and closely retain the heuristics of the serial SA algorithm. The computational speed of the SPAN algorithm scaled linearly with the number of processors on different computer platforms for a simple quadratic test problem and for a more complex forward dynamic simulation of human pedaling.

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

Kuz'mina, L. G., E-mail: kuzmina@igic.ras.ru; Sitin, A. G.; Gulakova, E. N.

The crystal and molecular structures of five styrylheterocycles of the quinoline series are studied. All molecules are planar. The double bond in the ethylene fragment is essentially localized. In the molecule of 2-(4-methylstyryl)quinoline, the ethylene fragment is disordered by the bicycle-pedal pattern. In four of the five compounds, the crystal packings do not contain stacking dimers prearranged for the [2+2] photocycloaddition (PCA) reaction. In the crystal of 2-(3-nitrostyryl)quinoline, pairs of crystallographically independent molecules form stacking dimers. In a dimer, the ethylene fragments have a twist orientation, which is incompatible with the PCA reaction. An attempt to initiate a temperature-dependent processmore » of bicyclepedal isomerization in the crystal and, as a consequence, the PCA reaction by means of simultaneous irradiation and heating of a single crystal is unsuccessful.« less

Training the Motor Aspects of Pre-driving Skills of Young Adults With and Without Autism Spectrum Disorder.

PubMed

Brooks, Johnell; Kellett, Julie; Seeanner, Julia; Jenkins, Casey; Buchanan, Caroline; Kinsman, Anne; Kelly, Desmond; Pierce, Susan

2016-07-01

The purpose of this study was to investigate the utility of using a driving simulator to address the motor aspects of pre-driving skills with young adults with Autism Spectrum Disorder (ASD). A group of neurotypical control participants and ten participants with ASD completed 18 interactive steering and pedal exercises with the goal to achieve error-free performance. Most participants were able to achieve this goal within five trials for all exercises except for the two most difficult ones. Minimal performance differences were observed between the two groups. Participants with ASD needed more time to complete the tasks. Overall, the interactive exercises and the process used worked well to address motor related aspects of pre-driving skills in young adults with ASD.

New evidence from China for the nature of the pterosaur evolutionary transition

NASA Astrophysics Data System (ADS)

Wang, Xiaoli; Jiang, Shunxing; Zhang, Junqiang; Cheng, Xin; Yu, Xuefeng; Li, Yameng; Wei, Guangjin; Wang, Xiaolin

2017-02-01

Pterosaurs are extinct flying reptiles, the first vertebrates to achieve powered flight. Our understanding of the evolutionary transition between basal, predominantly long-tailed forms to derived short-tailed pterodactyloids remained poor until the discovery of Wukongopterus and Darwinopterus in western Liaoning, China. In this paper we report on a new genus and species, Douzhanopterus zhengi, that has a reduced tail, 173% the length of the humerus, and a reduced fifth pedal digit, whose first phalange is ca. 20% the length of metatarsal III, both unique characters to Monofenestra. The morphological comparisons and phylogenetic analysis presented in this paper demonstrate that Douzhanopterus is the sister group to the ‘Painten pro-pterodactyloid’ and the Pterodactyloidea, reducing the evolutionary gap between long- and short-tailed pterosaurs.

Flight Investigation of Effect of Various Vertical-Tail Modifications on the Directional Stability and Control Characteristics of the P-63A-1 Airplane (AAF No. 42-68889)

NASA Technical Reports Server (NTRS)

Johnson, Harold I.

1946-01-01

Because the results of preliminary flight tests had indicated. the P-63A-1 airplane possessed insufficient directional stability, the NACA and the manufacturer (Bell Aircraft Corporation) suggested three vertical-tail modifications to remedy the deficiencies in the directional characteristics. These modifications included an enlarged vertical tail formed by adding a tip extension to the original vertical tail, a large sharp-edge ventral fin, and a small dorsal fin. The enlarged vertical tail involved only a slight increase in total vertical-tail area from 23.73 to 26.58 square feet but a relatively much larger increase in geometric aspect ratio from 1.24 to 1.73 based on height and area above the horizontal tail. At the request of the Air Material Command, Army Air Forces, flight tests were made to determine the effect of these modifications and of some combinations of these modifications on the directional stability and control characteristics of the airplane, In all, six different vertical-tail. configurations were investigated to determine the lateral and directional oscillation characteristics of the airplane, the sideslip characteristics, the yaw due to ailerons in rudder-fixed rolls from turns and pull-outs, the trim changes due to speed changes; and the trim changes due to power changes. Results of the tests showed that the enlarged vertical tail approximately doubled the directional stability of the airplane and that the pilots considered the directional stability provided by the enlarged vertical tail to be satisfactory. Calculations based on sideslip data obtained at an indicated airspeed of 300 miles per hour showed that the directional stability of the airplane with the original vertical tail corresponded to a value of 0(sub n beta) of -0.00056 whereas for the enlarged vertical tail the estimated va1ue of C(sub n beta) was -0.00130, The ventral fin was found to increase by a moderate amount the directional stability of the airplane with the original vertical tail for smal1 sides1ip angles at low speeds but little consistent change in directional stability was effected by the ventral fin at higher speeds, The effectiveness of the ventral fin was generally much less when used with the enlarged vertical tail than when used with the original vertical tail. The ventral and dorsal fins were found to be very effective in eliminating rudder-force reversals which occurred in low-speed, high-engine-power, sideslipped conditions of flight . Sideslip tests at two altitudes for approximately the sane engine power and indicated airspeed showed that a small decrease in static directional stability occurred with increasing altitude and this decrease in stability was attributed to the increased propeller blade angles required at high altitudes. The variations of rudder pedal force with indicated airspeed using normal rated power and a constant rudder tab setting through the speed range were desirably small for all the configurations tested. The rudder pedal force changed by about 50 pounds for a power change from engine idling power, to normal rated power and this pedal force change was largely independent of airspeed or of vertical-tail configuration for the various configurations tested.

Teenager male with burning pain in extremities--suspect Fabry disease, 2 case reports.

PubMed

Patil, Rajesh B; Joglekar, V K

2014-01-01

We present 2 cases of teenager males presented with burning pain in extremities and turned out to be cases of Fabry disease.The purpose of presenting this case is to highlight the fact that suspicion of Fabry disease in patients presenting with these symptoms will lead to early diagnosis and treatment of this condition before occurrences of complications. A 14-year-old male presented with severe burning pain in both hands and feet since last 4 yrs which persisted despite consumption of painkillers and becoming more disabling and without having any family history for such condition. On general examination patient had small reddish coloured lesions around the umbilicus, appearing like angiokeratomas. Skin biopsy confirmed the lesion. On enzyme assay his alpha galactosidase activity found to be '0' nmol/hr/mg of protein, confirming his diagnosis. Patient's creatinine and 2 D ECHO were normal and urine had 1+ proteinuria. Patient started on carbamazepine tablets for pain and referred to higher centre for genetic diagnosis and enzyme replacement therapy. CASE REPORT 2: An 18-year-old male referred to our hospital by general practitioner for fatigue and pedal oedema with deranged renal function tests. On history taking patient gave history of severe burning pain in both hands and feet since age of 9 yrs. Patient's general examination revealed hypertension with pallor, pedal oedema along with angiokeratomas in bathing suit distribution. Patient's ultrasonography of kidney revealed bilaterally normal sized kidneys with altered echotexture and urine examination showed fine granular foamy cells with sub nephrotic range proteinuria. 2 D ECHO revealed concentric left ventricular hypertrophy. Skin biopsy report supported the diagnosis of Fabry disease. Patient advised to undergo renal biopsy to confirm Fabry nephropathy but patient denied any further diagnostic workup for nephropathy or Fabry disease. Patient started on conservative treatment and carbamazepine in renal dose given for acroparaesthesias. On discharge patient has been advised to visit higher centre for further diagnostic work up and enzyme replacement therapy. Suspicion of Fabry disease in teenager males presenting with symptoms of burning pain in extremities may lead to early diagnosis and treatment of this condition before occurrences of complications.

An experiment on rider stability while mounting: Comparing middle-aged and elderly cyclists on pedelecs and conventional bicycles.

PubMed

Twisk, D A M; Platteel, S; Lovegrove, G R

2017-08-01

Pedelecs, popular among elderly cyclists, are associated with a higher injury risk than conventional bicycles. About 17% of these injuries are due to falls while (dis)mounting. Using instrumented bicycles, this study aimed to identify factors contributing to the stability of self-chosen mounting methods in four user groups: 30-45 versus 65+ years of age and males versus females. Mounting stability on pedelecs was compared with that on conventional bicycles, in controlled experimental setting (task in a fenced off parking lot) but also in real traffic conditions (traffic light turns green). Two mounting phases were differentiated: phase 1 as the transition from 'earth bound' to 'balance' and phase 2 as the acceleration to achieve harmonized cycling. Stability was operationalised in terms of the duration of these phases: the shorter their duration, the higher the stability. Pedelecs were shown to be less stable in phase 1 than conventional bicycles, irrespective of user group. For all user groups, only in phase 2 the advantages of electrical support kicked in. Results obtained in traffic conditions confirmed the patterns obtained in the controlled setting, with as only difference a lower speed in traffic conditions, which held for both mounting phases and bicycle types. Also measures of physical limitations due to low muscle strength were shown only to be compensated for by pedal support in phase 2 and not in phase 1. Further, mounting characteristics affected pedelec stability in phase 1 and not in phase 2. Higher stability was associated with a) starting while seated and b) using the pedal to push off. Although, these mounting characteristics were confounded with age, gender, and muscle strength, the pattern of results still suggest certain mounting techniques to be more beneficial for pedelecs. The results further illustrate the importance of a deeper understanding of the interactions of bicycle types and user groups on critical manoeuvres and their potential contribution to the optimisation of pedelec design and the training of safe mounting techniques. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of Knee Alignments and Toe Clip on Frontal Plane Knee Biomechanics in Cycling

PubMed Central

Shen, Guangping; Zhang, Songning; Bennett, Hunter J.; Martin, James C.; Crouter, Scott E.; Fitzhugh, Eugene C.

2018-01-01

Effects of knee alignment on the internal knee abduction moment (KAM) in walking have been widely studied. The KAM is closely associated with the development of medial knee osteoarthritis. Despite the importance of knee alignment, no studies have explored its effects on knee frontal plane biomechanics during stationary cycling. The purpose of this study was to examine the effects of knee alignment and use of a toe clip on the knee frontal plane biomechanics during stationary cycling. A total of 32 participants (11 varus, 11 neutral, and 10 valgus alignment) performed five trials in each of six cycling conditions: pedaling at 80 rpm and 0.5 kg (40 Watts), 1.0 kg (78 Watts), and 1.5 kg (117 Watts) with and without a toe clip. A motion analysis system and a customized instrumented pedal were used to collect 3D kinematic and kinetic data. A 3 × 2 × 3 (group × toe clip × workload) mixed design ANOVA was used for statistical analysis (p < 0.05). There were two different knee frontal plane loading patterns, internal abduction and adduction moment, which were affected by knee alignment type. The knee adduction angle was 12.2° greater in the varus group compared to the valgus group (p = 0.001), yet no difference was found for KAM among groups. Wearing a toe clip increased the knee adduction angle by 0.95º (p = 0.005). The findings of this study indicate that stationary cycling may be a safe exercise prescription for people with knee malalignments. In addition, using a toe clip may not have any negative effects on knee joints during stationary cycling. Key points Varus or valgus alignment did not cause increased frontal-plane knee joint loading, suggesting stationary cycling is a safe exercise. This study supports that using a toe clip did not lead to abnormal frontal-plane knee loading during stationary cycling. Two different knee frontal plane loading patterns, knee abduction and adduction moment, were observed during stationary cycling, which are likely affected by the type of knee alignment. PMID:29769833

High intensity interval and moderate continuous cycle training in a physical education programme improves health-related fitness in young females.

PubMed

Mazurek, K; Zmijewski, P; Krawczyk, K; Czajkowska, A; Kęska, A; Kapuściński, P; Mazurek, T

2016-06-01

The aim of the study was to investigate the effects of eight weeks of regular physical education classes supplemented with high intensity interval cycle exercise (HIIE) or continuous cycle exercises of moderate intensity (CME). Forty-eight collegiate females exercising in two regular physical education classes per week were randomly assigned to two programmes (HIIE; n = 24 or CME; n = 24) of additional (one session of 63 minutes per week) physical activity for 8 weeks. Participants performed HIIE comprising 2 series of 6x10 s sprinting with maximal pedalling cadence and active recovery pedalling with intensity 65%-75% HRmax or performed CME corresponding to 65%-75% HRmax. Before and after the 8-week programmes, anthropometric data and aero- and anaerobic capacity were measured. Two-way ANOVA revealed a significant time main effect for VO2max (p < 0.001), similar improvements being found in both groups (+12% in HIIE and +11% in CME), despite body mass not changing significantly (p = 0.59; +0.4% in HIIE and -0.1% in CME). A significant main time effect was found for relative fat mass (FM) and fat-free mass (FFM) (p < 0.001 and p < 0.001, respectively). A group x time interaction effect was found for relative FM and FFM (p = 0.018 and p = 0.018); a greater reduction in FM and greater increase in FFM were noted in the CME than the HIIE group. Improvements in anaerobic power were observed in both groups (p < 0.001), but it was greater in the HIIE group (interaction effect, p = 0.022). Weight loss is not mandatory for exercise-induced effects on improving aerobic and anaerobic capacity in collegiate females. Eight weeks of regular physical education classes supplemented with CME sessions are more effective in improving body composition than physical education classes supplemented with HIIE sessions. In contrast to earlier, smaller trials, similar improvements in aerobic capacity were observed following physical activity with additional HIIE or CME sessions.

I/Ca records of local redox history for contrasting depositional environments during Cenomanian-Turonian OAE2

NASA Astrophysics Data System (ADS)

Lu, Z.; Zhou, X.; Junium, C. K.; Sageman, B. B.; Jenkyns, H.

2012-12-01

Periods of catastrophic marine oxygen-depletion are known as Oceanic Anoxic Events (OAEs). The most severe OAE intervals in the geological record can be recognized by both positive and negative δ13C excursions, indicating major changes in the global carbon cycle. However, such geochemical expressions only mark the most significant periods of the OAE, characterized by massive carbon burial and/or injection of isotopically light carbon into the ocean-atmosphere system, effects that typically developed after the initial build-up of anoxic/euxinic conditions in many different basins worldwide. Iodide (I-) and iodate (IO3-) are the thermodynamically stable inorganic forms of iodine in seawater. Iodate is almost completely reduced to iodide in all investigated anoxic basins and OMZs. In a pilot study (Lu et al., 2010, Geology), I/Ca in synthetic calcite recorded iodate concentrations in the medium. This established the potential for I/Ca as a novel redox proxy and it was applied in two carbonate-rich sections recording the early Toarcian OAE (shallow-water carbonate platform site) and the Cenomanian-Turonian OAE 2 (pelagic chalk, Eastbourne, UK). Here we report preliminary I/Ca data from three more Cretaceous OAE 2 sections: Raia del Pedale (Italy), South Ferriby (UK), and Denver (USA) representing the Western Interior Seaway. Raia del Pedale is a shallow-water carbonate platform site. It has lower I/Ca values compared to those of the pelagic sites and the reducing condition lasted relatively longer. I/Ca data from the South Ferriby section have baseline values similar to those at Eastbourne (both are in chalk facies), while positive spikes on the profile may record upwelling episodes. The Western Interior Seaway site shows unique trends in redox conditions during the OAE, consistent with changes in TOC content. These preliminary data indicate that the development of reducing conditions was not synchronous on a global scale and that local environmental factors modified the global OAE imprint. The findings highlight the potential sensitivity of I/Ca as a proxy for reconstruction of redox histories.

Simple force feedback for small virtual environments

NASA Astrophysics Data System (ADS)

Schiefele, Jens; Albert, Oliver; van Lier, Volker; Huschka, Carsten

1998-08-01

In today's civil flight training simulators only the cockpit and all its interaction devices exist as physical mockups. All other elements such as flight behavior, motion, sound, and the visual system are virtual. As an extension to this approach `Virtual Flight Simulation' tries to subsidize the cockpit mockup by a 3D computer generated image. The complete cockpit including the exterior view is displayed on a Head Mounted Display (HMD), a BOOM, or a Cave Animated Virtual Environment. In most applications a dataglove or virtual pointers are used as input devices. A basic problem of such a Virtual Cockpit simulation is missing force feedback. A pilot cannot touch and feel buttons, knobs, dials, etc. he tries to manipulate. As a result, it is very difficult to generate realistic inputs into VC systems. `Seating Bucks' are used in automotive industry to overcome the problem of missing force feedback. Only a seat, steering wheel, pedal, stick shift, and radio panel are physically available. All other geometry is virtual and therefore untouchable but visible in the output device. In extension to this concept a `Seating Buck' for commercial transport aircraft cockpits was developed. Pilot seat, side stick, pedals, thrust-levers, and flaps lever are physically available. All other panels are simulated by simple flat plastic panels. They are located at the same location as their real counterparts only lacking the real input devices. A pilot sees the entire photorealistic cockpit in a HMD as 3D geometry but can only touch the physical parts and plastic panels. In order to determine task performance with the developed Seating Buck, a test series was conducted. Users press buttons, adapt dials, and turn knobs. In a first test, a complete virtual environment was used. The second setting had a plastic panel replacing all input devices. Finally, as cross reference the participants had to repeat the test with a complete physical mockup of the input devices. All panels and physical devices can be easily relocated to simulate a different type of cockpit. Maximal 30 minutes are needed for a complete adaptation. So far, an Airbus A340 and a generic cockpit are supported.

Guaifenesin alone or in combination with ketamine or sodium pentobarbital as an anesthetic in rabbits.

PubMed Central

Olson, M E; McCabe, K; Walker, R L

1987-01-01

Guaifenesin was administered alone and in combination with ketamine or sodium pentobarbital to adult New Zealand white rabbits. A solution of 5% guaifenesin in 5% dextrose given intravenously at a dosage of 200 mg/kg, abolished the pedal, palpebral and corneal reflexes for up to 15 minutes with little influence on cardiopulmonary function. Guaifenesin (200 mg/kg, intravenously) and ketamine (50 mg/kg, intramuscularly) produced effective and safe surgical anesthesia for over 30 minutes. This combination mildly depressed respiratory rate but heart rate and arterial blood pressure were not significantly affected. Guaifenesin (200 mg/kg, intravenously) was combined with sodium pentobarbital (20 mg/kg, intravenously) to produce surgical anesthesia for a period of more than 30 minutes. This combination depressed respiratory rate, produced a tachycardia and decreased arterial blood pressure. PMID:3651894

Insights into adhesion of abalone: A mechanical approach.

PubMed

Li, Jing; Zhang, Yun; Liu, Sai; Liu, Jianlin

2018-01-01

Many living creatures possess extremely strong capability of adhesion, which has aroused great attention of many scientists and engineers. Based on the self-developed equipment, we measured the normal and shear adhesion strength of the abalone underwater and out of water on different contact surfaces. It is found that the adhesion force of the abalone can amount to 200 or 300 times its body weight. The effects of wettability and roughness of the surface, and the frictional coefficient of mucus on the adhesion strength have been discussed. The theoretical calculation manifests that the normal adhesion force mainly stems from the suction pressure, van der Waals force and capillary force of the pedal, and their limit values are given. These findings may provide some inspirations to engineer new-typed materials, micro-devices, adhesives and medicine. Copyright © 2017 Elsevier Ltd. All rights reserved.

Postcorrective surgery improvement of nocturnal hypoxemia in a case of partial anomalous pulmonary venous connection and aberrant hepatic vein drainage.

PubMed

Agrawal, Abhinav; Palkar, Atul V; Sahni, Sonu; Vatsia, Sheel K; Shah, Rakesh D; Talwar, Arunabh

2016-01-01

Partial anomalous pulmonary venous connection (PAPVC) is a rare congenital anomaly that leads to an anatomical left-to-right shunt. Termination of the intrahepatic inferior vena cava (IVC) with its azygos continuation associated with the hepatic venous connection to the left atrium (LA) is also a rare congenital anomaly that results in an anatomical right-to-left shunt. A 65-year-old male presented with severe dyspnea on exertion and pedal edema. He was further diagnosed at our clinic and was found to have both the aforementioned congenital abnormalities, creating a bidirectional shunt. On further investigation, he was found to have nocturnal hypoxemia on overnight oximetry. The patient was successfully treated via surgical corrections of the congenital anomalies leading to symptomatic improvement as well as the resolution of nocturnal hypoxemia.

Morphology of the olfactory system in the predatory mite Phytoseiulus persimilis.

PubMed

van Wijk, Michiel; Wadman, Wytse J; Sabelis, Maurice W

2006-01-01

The predatory mite Phytoseiulus persimilis locates its prey, the two-spotted spider mite, by means of herbivore-induced plant volatiles. The olfactory response to this quantitatively and qualitatively variable source of information is particularly well documented. The mites perform this task with a peripheral olfactory system that consists of just five putative olfactory sensilla that reside in a dorsal field at the tip of their first pair of legs. The receptor cells innervate a glomerular olfactory lobe just ventral of the first pedal ganglion. We have made a 3D reconstruction of the caudal half of the olfactory lobe in adult females. The glomerular organization as well as the glomerular innervation appears conserved across different individuals. The adult females have, by approximation, a 1:1 ratio of olfactory receptor cells to olfactory glomeruli.

Developing Physiologic Models for Emergency Medical Procedures Under Microgravity

NASA Technical Reports Server (NTRS)

Parker, Nigel; O'Quinn, Veronica

2012-01-01

Several technological enhancements have been made to METI's commercial Emergency Care Simulator (ECS) with regard to how microgravity affects human physiology. The ECS uses both a software-only lung simulation, and an integrated mannequin lung that uses a physical lung bag for creating chest excursions, and a digital simulation of lung mechanics and gas exchange. METI s patient simulators incorporate models of human physiology that simulate lung and chest wall mechanics, as well as pulmonary gas exchange. Microgravity affects how O2 and CO2 are exchanged in the lungs. Procedures were also developed to take into affect the Glasgow Coma Scale for determining levels of consciousness by varying the ECS eye-blinking function to partially indicate the level of consciousness of the patient. In addition, the ECS was modified to provide various levels of pulses from weak and thready to hyper-dynamic to assist in assessing patient conditions from the femoral, carotid, brachial, and pedal pulse locations.

Developing Physiologic Models for Emergency Medical Procedures Under Microgravity

NASA Technical Reports Server (NTRS)

Parker, Nigel; OQuinn, Veronica

2012-01-01

Several technological enhancements have been made to METI's commercial Emergency Care Simulator (ECS) with regard to how microgravity affects human physiology. The ECS uses both a software-only lung simulation, and an integrated mannequin lung that uses a physical lung bag for creating chest excursions, and a digital simulation of lung mechanics and gas exchange. METI's patient simulators incorporate models of human physiology that simulate lung and chest wall mechanics, as well as pulmonary gas exchange. Microgravity affects how O2 and CO2 are exchanged in the lungs. Procedures were also developed to take into affect the Glasgow Coma Scale for determining levels of consciousness by varying the ECS eye-blinking function to partially indicate the level of consciousness of the patient. In addition, the ECS was modified to provide various levels of pulses from weak and thready to hyper-dynamic to assist in assessing patient conditions from the femoral, carotid, brachial, and pedal pulse locations.

The effects of alternative input devices and repeated exposures on the Test of Basic Aviation Skills (TBAS) performance.

PubMed

Momen, Nausheen

2009-12-01

The use of computer-based, psychomotor testing systems for personnel selection and classification has gained popularity in the civilian and military worlds in recent years. However, several issues need to be resolved before adopting a computerized, psychomotor test. The purpose of this study was to compare the impact of alternative input devices used for the Test Of Basic Aviation Skills (TBAS) as well as to explore the practice effects of the TBAS. In study 1, participants were administered the TBAS tracking tests once with a throttle and once with foot pedals in a classic test-retest paradigm. The results confirmed that neither of the input devices provided a significant advantage on TBAS performance. In study 2, participants were administered the TBAS twice with a 24-hour interval between testing. The results demonstrated significant practice effects for all the TBAS subtests except for the dichotic listening tests.

Effects of naturalistic cell phone conversations on driving performance.

PubMed

Rakauskas, Michael E; Gugerty, Leo J; Ward, Nicholas J

2004-01-01

The prevalence of automobile drivers talking on cell phones is growing, but the effect of that behavior on driving performance is unclear. Also unclear is the relationship between the difficulty level of a phone conversation and the resulting distraction. This study used a driving simulator to determine the effect that easy and difficult cell phone conversations have on driving performance. Cell phone use caused participants to have higher variation in accelerator pedal position, drive more slowly with more variation in speed, and report a higher level of workload regardless of conversation difficulty level. Drivers may cope with the additional stress of phone conversations by enduring higher workloads or setting reduced performance goals. Because an increasing number of people talk on the phone while driving, crashes caused by distracted drivers using cell phones will cause disruptions in business, as well as injury, disability, and permanent loss of personnel.

Immobilization of free-ranging maned wolf (Chrysocyon brachyurus) with tiletamine and zolazepam in central Brazil.

PubMed

Furtado, Mariana Malzoni; Kashivakura, Cynthia Kayo; Ferro, Claudia; de Almeida, Jácomo Anah Tereza; Silveira, Leandro; Astete, Samuel

2006-03-01

A tiletamine hydrochloride-zolazepam hydrochloride combination was used successfully to immobilize 27 free-ranging maned wolves (Chrysocyon brachyurus) at a mean dose of 2.77+/-0.56 (mean+/-SD) mg/kg. The induction time ranged from 3-15 min. Animals remained immobilized for periods of 48.56 +/-12.65 min. Compulsive licking, excessive salivation, muscle twitching, muscle tremors, tachypnea, and bradycardia were observed associated with the induction of the anesthesia in 13 of 27 maned wolves. Muscle twitching, pedal withdrawal reflex, muscle tremors, and ataxia were observed during recovery in three (11%) maned wolves. There were no significant differences in heart rates (P = 0.44), respiratory rates (P = 0.82), and rectal temperatures (P = 0.54) recorded at 5, 15, and 25 min after induction at these dosages. The tiletamine hydrochloride-zolazepam hydrochloride combination was shown to be an effective and safe immobilizing agent for free-ranging maned wolves.

Cultural variation in the focus on goals versus processes of actions.

PubMed

Miyamoto, Yuri; Knoepfler, Christopher A; Ishii, Keiko; Ji, Li-Jun

2013-06-01

Everyday actions (e.g., riding a bike) can be described in ways that emphasize either the goals of the action by adapting a higher level identification (e.g., getting exercise) or the processes of the action by adapting a lower level identification (e.g., pedaling). In Studies 1 and 2, we demonstrate cultural differences in focusing on the process or goal of actions at the individual level: Americans are more likely than Japanese to focus on the goal (rather than the process) of actions. Study 3 recruited Chinese participants in addition to American and Japanese participants and found that cultural differences in action identification are partly explained by cultural differences in self-consistency. Study 4 further showed cultural differences at the collective level: American media presents more goal-oriented information and less process-oriented information than does Japanese media. These findings highlight the role of culture in shaping how people attend to different aspects of actions.

A Traction Control Strategy with an Efficiency Model in a Distributed Driving Electric Vehicle

PubMed Central

Lin, Cheng

2014-01-01

Both active safety and fuel economy are important issues for vehicles. This paper focuses on a traction control strategy with an efficiency model in a distributed driving electric vehicle. In emergency situation, a sliding mode control algorithm was employed to achieve antislip control through keeping the wheels' slip ratios below 20%. For general longitudinal driving cases, an efficiency model aiming at improving the fuel economy was built through an offline optimization stream within the two-dimensional design space composed of the acceleration pedal signal and the vehicle speed. The sliding mode control strategy for the joint roads and the efficiency model for the typical drive cycles were simulated. Simulation results show that the proposed driving control approach has the potential to apply to different road surfaces. It keeps the wheels' slip ratios within the stable zone and improves the fuel economy on the premise of tracking the driver's intention. PMID:25197697

A traction control strategy with an efficiency model in a distributed driving electric vehicle.

PubMed

Lin, Cheng; Cheng, Xingqun

2014-01-01

Both active safety and fuel economy are important issues for vehicles. This paper focuses on a traction control strategy with an efficiency model in a distributed driving electric vehicle. In emergency situation, a sliding mode control algorithm was employed to achieve antislip control through keeping the wheels' slip ratios below 20%. For general longitudinal driving cases, an efficiency model aiming at improving the fuel economy was built through an offline optimization stream within the two-dimensional design space composed of the acceleration pedal signal and the vehicle speed. The sliding mode control strategy for the joint roads and the efficiency model for the typical drive cycles were simulated. Simulation results show that the proposed driving control approach has the potential to apply to different road surfaces. It keeps the wheels' slip ratios within the stable zone and improves the fuel economy on the premise of tracking the driver's intention.

Rhesus leg muscle EMG activity during a foot pedal pressing task on Bion 11

NASA Technical Reports Server (NTRS)

Hodgson, J. A.; Riazansky, S. N.; Goulet, C.; Badakva, A. M.; Kozlovskaya, I. B.; Recktenwald, M. R.; McCall, G.; Roy, R. R.; Fanton, J. W.; Edgerton, V. R.

2000-01-01

Rhesus monkeys (Macaca mulatta) were trained to perform a foot lever pressing task for a food reward. EMG activity was recorded from selected lower limb muscles of 2 animals before, during, and after a 14-day spaceflight and from 3 animals during a ground-based simulation of the flight. Integrated EMG activity was calculated for each muscle during the 20-min test. Comparisons were made between data recorded before any experimental manipulations and during flight or flight simulation. Spaceflight reduced soleus (Sol) activity to 25% of preflight levels, whereas it was reduced to 50% of control in the flight simulation. During flight, medial gastrocnemius (MG) activity was reduced to 25% of preflight activity, whereas the simulation group showed normal activity levels throughout all tests. The change in MG activity was apparent in the first inflight recording, suggesting that some effect of microgravity on MG activity was immediate.

Superficial Femoral Artery Intervention by Single Transpedal Arterial Access.

PubMed

Amoroso, Nicholas S; Shah, Sooraj; Liou, Michael; Ratcliffe, Justin; Lala, Moinakhtar; Diwan, Ravi; Huang, Yili; Rosero, Hugo; Coppola, John; Bertrand, Olivier F; Kwan, Tak W

2015-11-01

Atherosclerotic disease of the superficial femoral artery (SFA) is frequently seen and can be treated with percutaneous interventions, traditionally via femoral artery access. There are limited reports of transpedal artery access for peripheral artery interventions, but none to date describing routine primary transpedal artery approach for SFA stenting. In this preliminary study, we report 4 patients who underwent successful endovascular SFA stenting using a single transpedal artery access via a new ultra-low profile 6 Fr sheath (Glidesheath Slender; Terumo Corporation). All patients underwent successful SFA stenting without complication. Procedure time varied from 51 to 72 minutes. The mean contrast amount used was 56 mL; mean fluoroscopy time was 21 minutes; mean radiation dose was 91 mGy. At 1-month follow-up, duplex ultrasonography showed that all pedal arteries had remained patent. Transpedal artery approach as a primary approach to SFA stenting appears feasible and safe. Comparative trials with standard percutaneous femoral approach are warranted.

Quantifying phalangeal curvature: an empirical comparison of alternative methods.

PubMed

Stern, J T; Jungers, W L; Susman, R L

1995-05-01

It has been generally assumed and theoretically argued that the curvature of finger and toe bones seen in some nonhuman primates is associated with cheiridial use in an arboreal setting. Assessment of such curvature in fossil primates has been used to infer the positional behavior of these animals. Several methods of quantifying curvature of bones have been proposed. The measure most commonly applied to phalanges is that of included angle, but this has come under some criticism. We consider various other approaches for quantifying phalangeal curvature, demonstrating that some are equivalent to use of included angle, but that one--normalized curvature moment arm (NCMA)--represents a true alternative. A comparison of NCMA to included angle, both calculated on manual and pedal proximal phalanges of humans, apes, some monkeys, and the Hadar fossils, revealed that these two different measures of curvature are highly correlated and result in very similar distributional patterns.

SQUAMOUS CELL CARCINOMA IN TWO SNOW LEOPARDS (UNCIA UNCIA) WITH UNUSUAL AURICULAR PRESENTATION.

PubMed

Quintard, Benoît; Greunz, Eva Maria; Lefaux, Brice; Lemberger, Karin; Leclerc, Antoine

2017-06-01

Squamous cell carcinoma (SCC) is well documented in snow leopards ( Uncia uncia ) and most common locations are oral, facial, or pedal. These two cases illustrate an unusual auricular presentation, which is more often reported in white domestic cats. The animals were aged and presented clinical signs of otitis such as head shaking and ear scratching. Clinical examinations showed auricular canal masses with chronic purulent otitis. In both cases, clinical deterioration led to euthanasia and histology of the ear canal was consistent with SCC and showed numerous vascular emboli. These cases illustrate an unreported aggressive localization for SCC in snow leopards, which should be included in the differential diagnosis of otitis in this species. Auricular SCC may be underdiagnosed as the ear canal is infrequently sampled for histopathology. This auricular localization should be considered when metastases are found upon necropsy without internal primary tumor.

Evaluation of the driver's cab in the Rc5 engine.

PubMed

Hedberg, G

1987-03-01

The opinion of engine drivers concerning the design of the cab in a new engine (Rc5, ASEA, Sweden) is surveyed in the present study, which is aimed at recommendations for further improvements of the new cab. Fifty engine drivers from the northern part of Sweden (Ange, Vannas and Boden), who had been driving the new engine, were selected at random to answer a specially designed questionnaire. Most of the drivers considered the new cab as better than the old one (Rc4) in several respects. Particularly appreciated was an adjustable footrest, on which the safety regulator pedal was fitted, which enabled an individually adjusted position for driving. They also preferred the automatic brake valve located close to the driver and with its movements in a sagittal direction. A number of proposals for further improvement of the cab are presented in order to attain an optimally designed driver's cab.

Design and analysis of sustainable paper bicycle

NASA Astrophysics Data System (ADS)

Roni Sahroni, Taufik; Nasution, Januar

2017-12-01

This paper presents the design of sustainable paper bicycle which describes the stage by stage in the production of paper bicycle. The objective of this project is to design a sustainable paper bicycles to be used for children under five years old. The design analysis emphasizes in screening method to ensure the design fulfil the safety purposes. The evaluation concept is presented in designing a sustainable paper bicycle to determine highest rating. Project methodology is proposed for developing a sustainable paper bicycle. Design analysis of pedal, front and rear wheel, seat, and handle were presented using AutoCAD software. The design optimization was performed to fulfil the safety factors by modifying the material size and dimension. Based on the design analysis results, it is found that the optimization results met the factor safety. As a result, a sustainable paper bicycle was proposed for children under five years old.

Post-exercise ketosis.

PubMed Central

Koeslag, J H; Noakes, T D; Sloan, A W

1980-01-01

1. The effect of exercise on blood ketone body concentrations was studied in trained athletes and in sedentary subjects pedalling a bicycle ergometer. 2. Although the untrained subjects had higher heart rates and blood lactate concentrations at the same work load as the athletes, neither group developed ketonaemia even after intense or prolonged exercise. 3. Older subjects developed post-exercise ketonaemia, reaching maximum about 3 hr after exercise. 4. A high-carbohydrate diet before the exercise could prevent the onset of post-exercise ketonaemia and a low-carbohydrate diet enhanced it. The highest post-exercise blood ketone levels were recorded in marathon runners after a "glycogen-stripping' regimen. 5. Concentrations of free fatty acids, glucose, growth hormone and insulin in blood after exercise followed different patterns from that of ketones. 6. Post-exercise ketosis, when it occurs in untrained subjects, may be due to a lower carbohydrate intake than that of athletes. PMID:6997456

Hybrid powertrain controller

DOEpatents

Jankovic, Miroslava; Powell, Barry Kay

2000-12-26

A hybrid powertrain for a vehicle comprising a diesel engine and an electric motor in a parallel arrangement with a multiple ratio transmission located on the torque output side of the diesel engine, final drive gearing connecting drivably the output shaft of transmission to traction wheels of the vehicle, and an electric motor drivably coupled to the final drive gearing. A powertrain controller schedules fuel delivered to the diesel engine and effects a split of the total power available, a portion of the power being delivered by the diesel and the balance of the power being delivered by the motor. A shifting schedule for the multiple ratio transmission makes it possible for establishing a proportional relationship between accelerator pedal movement and torque desired at the wheels. The control strategy for the powertrain maintains drivability of the vehicle that resembles drivability of a conventional spark ignition vehicle engine powertrain while achieving improved fuel efficiency and low exhaust gas emissions.

Severe peripheral neuropathy and elevated plantar pressures causing foot ulceration in pituitary gigantism.

PubMed

Jennings, A M; Robinson, A; Kandler, R H; Betts, R P; Ryder, R E; Cullen, D R

1993-07-01

We report two patients with treated pituitary gigantism and peripheral neuropathy, one of whom has chronic foot ulceration. Detailed neurophysiological assessment was performed on both patients. The patient with foot ulceration had clinical and neurophysiological evidence of severe neuropathy, whereas the patient without ulceration had only neurophysiological abnormalities. The sweating response to acetylcholine was markedly impaired in the feet of both patients, suggesting pedal autonomic denervation. Neither patient had evidence of diabetes mellitus and detailed investigation failed to reveal an alternative cause of peripheral neuropathy. Optical pedobarography revealed abnormally high pressure (> 10 kg/cm2) under the metatarsal heads of both patients, one such area coinciding with the area of ulceration. Thus in pituitary gigantism elevated plantar pressures may contribute to the development of foot ulceration when severe peripheral neuropathy is present. Furthermore, as in diabetes mellitus, impaired sweating may also increase the risk of ulceration as the resultant dry skin may develop fissures.

An Investigation of Large Tilt-Rotor Short-Term Attitude Response Handling Qualities Requirements in Hover

NASA Technical Reports Server (NTRS)

Malcipa, Carlos; Decker, William A.; Theodore, Colin R.; Blanken, Christopher L.; Berger, Tom

2010-01-01

A piloted simulation investigation was conducted using the NASA Ames Vertical Motion Simulator to study the impact of pitch, roll and yaw attitude bandwidth and phase delay on handling qualities of large tilt-rotor aircraft. Multiple bandwidth and phase delay pairs were investigated for each axis. The simulation also investigated the effect that the pilot offset from the center of gravity has on handling qualities. While pilot offset does not change the dynamics of the vehicle, it does affect the proprioceptive and visual cues and it can have an impact on handling qualities. The experiment concentrated on two primary evaluation tasks: a precision hover task and a simple hover pedal turn. Six pilots flew over 1400 data runs with evaluation comments and objective performance data recorded. The paper will describe the experiment design and methodology, discuss the results of the experiment and summarize the findings.

The Physiological Mechanisms of Performance Enhancement with Sprint Interval Training Differ between the Upper and Lower Extremities in Humans.

PubMed

Zinner, Christoph; Morales-Alamo, David; Ørtenblad, Niels; Larsen, Filip J; Schiffer, Tomas A; Willis, Sarah J; Gelabert-Rebato, Miriam; Perez-Valera, Mario; Boushel, Robert; Calbet, Jose A L; Holmberg, Hans-Christer

2016-01-01

To elucidate the mechanisms underlying the differences in adaptation of arm and leg muscles to sprint training, over a period of 11 days 16 untrained men performed six sessions of 4-6 × 30-s all-out sprints (SIT) with the legs and arms, separately, with a 1-h interval of recovery. Limb-specific VO 2 peak, sprint performance (two 30-s Wingate tests with 4-min recovery), muscle efficiency and time-trial performance (TT, 5-min all-out) were assessed and biopsies from the m. vastus lateralis and m. triceps brachii taken before and after training. VO 2 peak and Wmax increased 3-11% after training, with a more pronounced change in the arms ( P < 0.05). Gross efficiency improved for the arms (+8.8%, P < 0.05), but not the legs (-0.6%). Wingate peak and mean power outputs improved similarly for the arms and legs, as did TT performance. After training, VO 2 during the two Wingate tests was increased by 52 and 6% for the arms and legs, respectively ( P < 0.001). In the case of the arms, VO 2 was higher during the first than second Wingate test (64 vs. 44%, P < 0.05). During the TT, relative exercise intensity, HR, VO 2 , VCO 2 , V E , and V t were all lower during arm-cranking than leg-pedaling, and oxidation of fat was minimal, remaining so after training. Despite the higher relative intensity, fat oxidation was 70% greater during leg-pedaling ( P = 0.017). The aerobic energy contribution in the legs was larger than for the arms during the Wingate tests, although VO 2 for the arms was enhanced more by training, reducing the O 2 deficit after SIT. The levels of muscle glycogen, as well as the myosin heavy chain composition were unchanged in both cases, while the activities of 3-hydroxyacyl-CoA-dehydrogenase and citrate synthase were elevated only in the legs and capillarization enhanced in both limbs. Multiple regression analysis demonstrated that the variables that predict TT performance differ for the arms and legs. The primary mechanism of adaptation to SIT by both the arms and legs is enhancement of aerobic energy production. However, with their higher proportion of fast muscle fibers, the arms exhibit greater plasticity.

A comparison of medetomidine and its active enantiomer dexmedetomidine when administered with ketamine in mice

PubMed Central

2013-01-01

Background Medetomidine-ketamine (MK) and dexmedetomidine-ketamine (DK) are widely used to provide general anaesthesia in laboratory animals, but have not been compared directly in many of these species, including rodents. This study aimed to compare the onset and depth of anaesthesia, and changes in vital signs, after intraperitoneal (IP) or subcutaneous (SC) administration of ketamine (75 mg kg-1) combined with medetomidine (1 mg kg-1) or dexmedetomidine (0.5 mg kg-1) using a randomised semi-crossover design with ≥ 48 hours between treatments in 10 male and 10 female mice. Each mouse was anaesthetised twice using the same administration route (IP or SC): once with each drug-ketamine combination. Anaesthetised mice were monitored on a heating pad without supplemental oxygen for 89 minutes; atipamezole was administered for reversal. The times that the righting reflex was lost post-injection and returned post-reversal were analysed using general linear models. Tail-pinch and pedal reflexes were examined using binomial generalized linear models. Pulse rate (PR), respiratory rate (fr), and arterial haemoglobin saturation (SpO2) were compared using generalized additive mixed models. Results There were no significant differences among treatments for the times taken for loss and return of the righting reflex, or response of the tail-pinch reflex. The pedal withdrawal reflex was abolished more frequently with MK than DK over time (P = 0.021). The response of PR and SpO2 were similar among treatments, but fr was significantly higher with MK than DK (P ≤ 0.0005). Markedly low SpO2 concentrations occurred within 5 minutes post-injection (83.8 ± 6.7%) in all treatment groups and were most severe after 89 minutes lapsed (66.7 ± 7.5%). No statistical differences were detected in regards to administration route (P ≤ 0.94). Conclusions This study failed to demonstrate clinical advantages of the enantiomer dexmedetomidine over medetomidine when combined with ketamine to produce general anaesthesia in mice. At the doses administered, deep surgical anaesthesia was not consistently produced with either combination; therefore, anaesthetic depth must be assessed before performing surgical procedures. Supplemental oxygen should always be provided during anaesthesia to prevent hypoxaemia. PMID:23497612

Distinct Laterality in Forelimb-Movement Representations of Rat Primary and Secondary Motor Cortical Neurons with Intratelencephalic and Pyramidal Tract Projections.

PubMed

Soma, Shogo; Saiki, Akiko; Yoshida, Junichi; Ríos, Alain; Kawabata, Masanori; Sakai, Yutaka; Isomura, Yoshikazu

2017-11-08

Two distinct motor areas, the primary and secondary motor cortices (M1 and M2), play crucial roles in voluntary movement in rodents. The aim of this study was to characterize the laterality in motor cortical representations of right and left forelimb movements. To achieve this goal, we developed a novel behavioral task, the Right-Left Pedal task, in which a head-restrained male rat manipulates a right or left pedal with the corresponding forelimb. This task enabled us to monitor independent movements of both forelimbs with high spatiotemporal resolution. We observed phasic movement-related neuronal activity (Go-type) and tonic hold-related activity (Hold-type) in isolated unilateral movements. In both M1 and M2, Go-type neurons exhibited bias toward contralateral preference, whereas Hold-type neurons exhibited no bias. The contralateral bias was weaker in M2 than M1. Moreover, we differentiated between intratelencephalic (IT) and pyramidal tract (PT) neurons using optogenetically evoked spike collision in rats expressing channelrhodopsin-2. Even in identified PT and IT neurons, Hold-type neurons exhibited no lateral bias. Go-type PT neurons exhibited bias toward contralateral preference, whereas IT neurons exhibited no bias. Our findings suggest a different laterality of movement representations of M1 and M2, in each of which IT neurons are involved in cooperation of bilateral movements, whereas PT neurons control contralateral movements. SIGNIFICANCE STATEMENT In rodents, the primary and secondary motor cortices (M1 and M2) are involved in voluntary movements via distinct projection neurons: intratelencephalic (IT) neurons and pyramidal tract (PT) neurons. However, it remains unclear whether the two motor cortices (M1 vs M2) and the two classes of projection neurons (IT vs PT) have different laterality of movement representations. We optogenetically identified these neurons and analyzed their functional activity using a novel behavioral task to monitor movements of the right and left forelimbs separately. We found that contralateral bias was reduced in M2 relative to M1, and in IT relative to PT neurons. Our findings suggest that the motor information processing that controls forelimb movement is coordinated by a distinct cell population. Copyright © 2017 the authors 0270-6474/17/3710904-13$15.00/0.

Power, muscular work, and external forces in cycling.

PubMed

de Groot, G; Welbergen, E; Clijsen, L; Clarijs, J; Cabri, J; Antonis, J

1994-01-01

Cycling performance is affected by the interaction of a number of variables, including environment, mechanical, and human factors. Engineers have focused on the development of more efficient bicycles. Kinesiologists have examined cycling performance from a human perspective. This paper summarizes only certain aspects of human ergonomics of cycling, especially those which are important for the recent current research in our departments. Power is a key to performance of physical work. During locomotion an imaginary flow of energy takes place from the metabolism to the environment, with some efficiency. The 'useful' mechanical muscle power output might be used to perform movements and to do work against the environment. The external power is defined as the sum of joint powers, each calculated as the product of the joint (net) moment and angular velocity. This definition of external power is closely related to the mean external power as applied to exercise physiology: the sum of joint powers reflects all mechanical power which in principle can be used to fulfil a certain task. In this paper, the flow of energy for cycling is traced quantitatively as far as possible. Studies on the total lower limb can give insight into the contribution of individual muscles to external power. The muscle velocity (positive or negative) is obtained from the positions and orientations of body segments and a bar linkage model of the lower limb. The muscle activity can be measured by electromyography. In this way, positive and negative work regions in individual muscles are identified. Synergy between active agonistic/antagonistic muscle groups occurs in order to deliver external power. Maximum power is influenced by body position, geometry of the bicycle and pedalling rate. This has to be interpreted in terms of the length-tension and force-velocity-power relationships of the involved muscles. Flat road and uphill cycling at different saddle-tube angles is simulated on an ergometer. The measured pedal forces (magnitude and direction) are only dependent on the intersegmental orientation of saddle tube, crank position, upper and lower leg, and foot. The changed direction of the gravitational force with respect to the saddle-tube does not interfere with the co-ordinated force production pattern. During locomotory cycling at constant speed the external power is mainly used to overcome the aerodynamic friction force. This force and the rolling resistance are determined by coasting down experiments, yielding the external power.(ABSTRACT TRUNCATED AT 400 WORDS)

The Physiological Mechanisms of Performance Enhancement with Sprint Interval Training Differ between the Upper and Lower Extremities in Humans

PubMed Central

Zinner, Christoph; Morales-Alamo, David; Ørtenblad, Niels; Larsen, Filip J.; Schiffer, Tomas A.; Willis, Sarah J.; Gelabert-Rebato, Miriam; Perez-Valera, Mario; Boushel, Robert; Calbet, Jose A. L.; Holmberg, Hans-Christer

2016-01-01

To elucidate the mechanisms underlying the differences in adaptation of arm and leg muscles to sprint training, over a period of 11 days 16 untrained men performed six sessions of 4–6 × 30-s all-out sprints (SIT) with the legs and arms, separately, with a 1-h interval of recovery. Limb-specific VO2peak, sprint performance (two 30-s Wingate tests with 4-min recovery), muscle efficiency and time-trial performance (TT, 5-min all-out) were assessed and biopsies from the m. vastus lateralis and m. triceps brachii taken before and after training. VO2peak and Wmax increased 3–11% after training, with a more pronounced change in the arms (P < 0.05). Gross efficiency improved for the arms (+8.8%, P < 0.05), but not the legs (−0.6%). Wingate peak and mean power outputs improved similarly for the arms and legs, as did TT performance. After training, VO2 during the two Wingate tests was increased by 52 and 6% for the arms and legs, respectively (P < 0.001). In the case of the arms, VO2 was higher during the first than second Wingate test (64 vs. 44%, P < 0.05). During the TT, relative exercise intensity, HR, VO2, VCO2, VE, and Vt were all lower during arm-cranking than leg-pedaling, and oxidation of fat was minimal, remaining so after training. Despite the higher relative intensity, fat oxidation was 70% greater during leg-pedaling (P = 0.017). The aerobic energy contribution in the legs was larger than for the arms during the Wingate tests, although VO2 for the arms was enhanced more by training, reducing the O2 deficit after SIT. The levels of muscle glycogen, as well as the myosin heavy chain composition were unchanged in both cases, while the activities of 3-hydroxyacyl-CoA-dehydrogenase and citrate synthase were elevated only in the legs and capillarization enhanced in both limbs. Multiple regression analysis demonstrated that the variables that predict TT performance differ for the arms and legs. The primary mechanism of adaptation to SIT by both the arms and legs is enhancement of aerobic energy production. However, with their higher proportion of fast muscle fibers, the arms exhibit greater plasticity. PMID:27746738

Effect of epidural tramadol and lignocaine on physiological and behavioural changes in goats subjected to castration with a high tension band.

PubMed

Ajadi, R A; Owanikin, A O; Martins, M M; Gazal, O S

2012-11-01

To compare the effect of a single epidural injection of either lignocaine or tramadol on behavioural changes, anaesthetic indices, leucocyte parameters, erythrocyte sedimentation rates and concentration of cortisol in plasma in goats subjected to castration by high tension band. Ten male goats weighing 14.4 (SD 0.7) kg were randomly allocated to anaesthesia with epidural injections of tramadol (3 mg/kg), or lignocaine (4 mg/kg). Following anaesthesia, a rubber ring was applied and tensioned to the scrotal neck of each goat. Behavioural changes were noted as they occurred, and the onset of drug action (time between epidural injection and loss of pedal reflex) and duration of antinociception (time interval between disappearance and reappearance of pedal withdrawal reflex) were determined. Hearts rates, respiratory rates and rectal temperatures were determined every 15 minutes for a 90-minute period, while blood was obtained for determination of white cell counts, erythrocyte sedimentation rates and concentrations of cortisol. Anaesthetic indices were compared using Student's t-test, while physiological parameters were compared using an ANOVA for repeated measurements. Goats treated with epidural tramadol were not recumbent and continued rumination while goats treated with epidural lignocaine were recumbent and did not continue rumination. The onset of analgesia was longer (p=0.01) in goats treated with epidural tramadol (5.0 minutes; SD 1.2) than goats treated with epidural lignocaine (3.0 minutes; SD 1.1), while duration of analgesia was shorter (p=0.003) in goats treated with epidural tramadol (47.2 minutes; SD 13.1) than goats treated with epidural lignocaine (89.8 minutes; SD 23.1). There was no significant difference in heart rates, respiratory rates and erythrocyte sedimentation rates, while the concentration of cortisol in plasma differed (p<0.05) between goats treated with epidural tramadol and lignocaine. Epidural lignocaine injection produced longer duration of antinociception with lower frequency of pain-associated behavioural changes; while treatment with epidural tramadol injection allowed the goats to continue grazing once the rubber ring has been applied. Epidural tramadol produced partial pain relief, while epidural lignocaine injection provided the most effective pain control. However, epidural tramadol has an advantage over epidural lignocaine in conditions such as perineal surgery and caesarian section in cattle and where the ability of the animal to maintain standing is desired.

Free-Spinning-Tunnel Tests of a 1/24-Scale Model of the Grumman XF9F-2 Airplane, TED No. NACA DE 317

NASA Technical Reports Server (NTRS)

Berman, Theodore

1948-01-01

An investigation of the spin and recovery characteristics of a scale model of the Grumman XF9F-2 airplane has been conducted in the Langley 20-foot free-spinning tunnel. The effects of control settings and movements on the erect and inverted spin and recovery characteristics of the model in the flight loading were determined. The investigation also included spin-recovery-parachute, pilot-escape, and rudder-pedal- . force tests. The recovery characteristics of the model were satisfactory for all configurations tested. Spins for the normal control configuration were oscillatory in roll and yaw. Deflecting the leading-edge flaps or the dive brakes did not change the spin and recovery characteristics of the model noticeably. A 10.0-foot tail parachute or a 6.0-foot wing-tip parachute (drag coefficient of 0.75) was found to be effective for recoveries from demonstration spins. The rudder forces in the spin appeared to be within the capabilities of the pilot.

Task Performance and Meta-Cognitive Outcomes When Using Activity Workstations and Traditional Desks

PubMed Central

Pilcher, June J.; Baker, Victoria C.

2016-01-01

The purpose of the current study is to compare the effects of light physical activity to sedentary behavior on cognitive task performance and meta-cognitive responses. Thirty-eight undergraduate students participated in the study. The participants used a stationary bicycle with a desk top and a traditional desk while completing two complex cognitive tasks and measures of affect, motivation, morale, and engagement. The participants pedaled the stationary bicycle at a slow pace (similar in exertion to a normal walking pace) while working. The results indicated that cognitive task performance did not change between the two workstations. However, positive affect, motivation, and morale improved when using the stationary bicycle. These results suggest that activity workstations could be implemented in the work place and in educational settings to help decrease sedentary behavior without negatively affecting performance. Furthermore, individuals could experience a positive emotional response when working on activity workstations which in turn could help encourage individuals to choose to be more physical active during daily activities. PMID:27445921

Promoting physical activity in people with intellectual and multiple disabilities through a basic technology-aided program.

PubMed

Lancioni, Giulio E; Singh, Nirbhay N; O'Reilly, Mark F; Sigafoos, Jeff; Alberti, Gloria; Perilli, Viviana; Zimbaro, Carmen; Boccasini, Adele; Mazzola, Carlo; Russo, Roberto

2018-06-01

This study assessed a technology-aided program (monitoring responding, and ensuring preferred stimulation and encouragements) for promoting physical activity with 11 participants with severe/profound intellectual and multiple disabilities. Each participant was provided with an exercise device (e.g. a static bicycle and a stepper) and exposed to the program according to an ABAB design, in which A and B represented baseline and intervention phases, respectively. Data recording concerned (a) the participants' responses with the exercise device (e.g. pedaling) during baseline and intervention phases and (b) their heart rates during the last intervention phase. The results showed that all participants had significant increases in responding with the exercise devices during the intervention phases. Heart-rate values during the intervention sessions indicated that the participants' responding during those sessions mostly amounted to moderate-intensity physical activity, with potential benefits for their overall physical condition. Implications of the findings and questions for future research in the area were discussed.

Could gastropods crawl using Newtonian mucus?

NASA Astrophysics Data System (ADS)

Lai, Janice; Vazquez-Torres, Maria; Del Alamo, Juan C.; Rodriguez-Rodriguez, Javier; Lasheras, Juan C.

2010-11-01

The locomotion of terrestrial gastropods is driven by a train of periodic muscle contractions (pedal waves) and relaxations (interwaves) that propagate from their tail to their head (direct waves). We study the locomotion of these animals on smooth flat surfaces by measuring the three-dimensional displacements of the ventral foot surface induced by the passage of the waves. A simple model based on lubrication theory is proposed in accordance with the experimental observations. This model uncovers a new mode of locomotion that works even when the lubricant between the foot and the animal is Newtonian. The model can also be adapted to situations where the animal's foot is in contact with the ground only at discrete points, as is the case when it crawls on a wire mesh or on rough soil surfaces. Furthermore, comparison between the stress exerted by the animal on the substrate and the model predictions allows us to clarify the role of the complex rheology observed in the mucus of terrestrial gastropods.

Multi-platform experiment to cross a boundary between laboratory and real situational studies: experimental discussion of cross-situational consistency of driving behaviors.

PubMed

Terai, H; Miwa, K; Okuda, H; Tazaki, Y; Suzuki, T; Kojima, K; Morita, J; Maehigashi, A; Takeda, K

2012-01-01

We constructed an innovative experimental platform to study cross-situational consistency in driving behavior, conducted behavioral experiments, and reported the data obtained in the experiment. To discuss cross-situational consistency, we separated situations in which people use some systems to conduct tasks into three independent conceptual factors: environment, context, and system. We report the experimental results with the following systems: a laboratory system with a gaming controller and steering/pedal controllers and a real system, COMS an instrumented vehicle. The results are summarized as follows. 1) The individual behaviors in each system were stable, and consistency was retained. 2) The consistency of the behaviors was also confirmed when the participants drove using different interfaces in identical systems. 3) However, only slight correlation was observed across different systems in a specific situation where a strong high-order cognitive constraint (i.e., rapid driving) and a weak low-order cognitive constraint (driving with easy handling toward a straight-line course) were given.

A gigantic new dinosaur from Argentina and the evolution of the sauropod hind foot.

PubMed

González Riga, Bernardo J; Lamanna, Matthew C; Ortiz David, Leonardo D; Calvo, Jorge O; Coria, Juan P

2016-01-18

Titanosauria is an exceptionally diverse, globally-distributed clade of sauropod dinosaurs that includes the largest known land animals. Knowledge of titanosaurian pedal structure is critical to understanding the stance and locomotion of these enormous herbivores and, by extension, gigantic terrestrial vertebrates as a whole. However, completely preserved pedes are extremely rare among Titanosauria, especially as regards the truly giant members of the group. Here we describe Notocolossus gonzalezparejasi gen. et sp. nov. from the Upper Cretaceous of Mendoza Province, Argentina. With a powerfully-constructed humerus 1.76 m in length, Notocolossus is one of the largest known dinosaurs. Furthermore, the complete pes of the new taxon exhibits a strikingly compact, homogeneous metatarsus--seemingly adapted for bearing extraordinary weight--and truncated unguals, morphologies that are otherwise unknown in Sauropoda. The pes underwent a near-progressive reduction in the number of phalanges along the line to derived titanosaurs, eventually resulting in the reduced hind foot of these sauropods.

Performance of hybrid nano-micro reinforced mg metal matrix composites brake calliper: simulation approach

NASA Astrophysics Data System (ADS)

Fatchurrohman, N.; Chia, S. T.

2017-10-01

Most commercial vehicles use brake calliper made of grey cast iron (GCI) which possesses heavy weight. This contributes to the total weight of the vehicle which can lead to higher fuel consumption. Another major problem is GCI calliper tends to deflect during clamping action, known as “bending of bridge”. This will result in extended pedal travel. Magnesium metal matrix composites (Mg-MMC) has a potential application in the automotive industry since it having a lower density, higher strength and very good modulus of elasticity as compared to GCI. This paper proposed initial development of hybrid Mg-MMC brake calliper. This was achieved by analyzing the performance of hybrid nano-micro reinforced Mg-MMC and comparing with the conventional GCI brake calliper. It was performed using simulation in ANSYS, a finite element analysis (FEA) software. The results show that hybrid Mg-MMC has better performance in terms of reduction the weight of the brake calliper, reduction in total deformation/deflection and better ability to withstand equivalent elastic strain.

Independent component analysis for onset detection in piano trills

NASA Astrophysics Data System (ADS)

Brown, Judith C.; Todd, Jeremy G.; Smaragdis, Paris

2002-05-01

The detection of onsets in piano music is difficult due to the presence of many notes simultaneously and their long decay times from pedaling. This is even more difficult for trills where the rapid note changes make it difficult to observe a decrease in amplitude for individual notes in either the temporal wave form or the time dependent Fourier components. Occasionally one note of the trill has a much lower amplitude than the other making an unambiguous determination of its onset virtually impossible. We have analyzed a number of trills from CD's of performances by Horowitz, Ashkenazy, and Goode, choosing the same trill and different performances where possible. The Fourier transform was calculated as a function of time, and the magnitude coefficients served as input for a calculation using the method of independent component analysis. In most cases this gave a more definitive determination of the onset times, as can be demonstrated graphically. For comparison identical calculations have been carried out on recordings of midi generated performances on a Yamaha Disclavier piano.

Flow field interactions between two tandem cyclists

NASA Astrophysics Data System (ADS)

Barry, Nathan; Burton, David; Sheridan, John; Thompson, Mark; Brown, Nicholas A. T.

2016-12-01

Aerodynamic drag is the primary resistive force acting on cyclists at racing speeds. Many events involve cyclists travelling in very close proximity. Previous studies have shown that interactions result in significant drag reductions for inline cyclists. However, the interaction between cyclist leg position (pedalling) and the vortical flow structures that contribute significantly to the drag on an isolated cyclist has not previously been quantified or described for tandem cyclists of varying separation. To this end, scale model cyclists were constructed for testing in a water channel for inline tandem configurations. Particle image velocimetry was used to capture time-averaged velocity fields around two tandem cyclists. Perhaps surprisingly, the wake of a trailing cyclist maintains strong similarity to the characteristic wake of a single cyclist despite a significant disturbance to the upstream flow. Together with streamwise velocity measurements through the wake and upstream of the trailing cyclist, this work supports previous findings, which showed that the trailing cyclist drag reduction is primarily due to upstream sheltering effects reducing the stagnation pressure on forward-facing surfaces.

Eco Assist Techniques through Real-time Monitoring of BEV Energy Usage Efficiency

PubMed Central

Kim, Younsun; Lee, Ingeol; Kang, Sungho

2015-01-01

Energy efficiency enhancement has become an increasingly important issue for battery electric vehicles. Even if it can be improved in many ways, the driver’s driving pattern strongly influences the battery energy consumption of a vehicle. In this paper, eco assist techniques to simply implement an energy-efficient driving assistant system are introduced, including eco guide, eco control and eco monitoring methods. The eco guide is provided to control the vehicle speed and accelerator pedal stroke, and eco control is suggested to limit the output power of the battery. For eco monitoring, the eco indicator and eco report are suggested to teach eco-friendly driving habits. The vehicle test, which is done in four ways, consists of federal test procedure (FTP)-75, new european driving cycle (NEDC), city and highway cycles, and visual feedback with audible warnings is provided to attract the driver’s voluntary participation. The vehicle test result shows that the energy usage efficiency can be increased up to 19.41%. PMID:26121611

An ornithomimid (Dinosauria) bonebed from the Late Cretaceous of Alberta, with implications for the behavior, classification, and stratigraphy of North American ornithomimids.

PubMed

Cullen, Thomas M; Ryan, Michael J; Schröder-Adams, Claudia; Currie, Philip J; Kobayashi, Yoshitsugu

2013-01-01

Bonebeds can provide a wealth of anatomical, taphonomic, and ontogenetic information about the specimens preserved within them, and can provide evidence for inferred behavior. The material described here represents the first known bonebed of ornithomimids in North America, and the fourth record of an ornithomimosaur bonebed in the world. Partial skeletons representing three individuals are preserved in this assemblage, each comprising primarily portions of the posterior postcrania (pelvis, hind limbs and tail). All three individuals are morphologically similar, although one is larger in overall size. Given the stratigraphic position of the site, and the morphology of the postcrania, the preserved material represents a taxon from the clade containing Ornithomimus and Struthiomimus. Pedal ungual morphology is examined and found to be too variable to be useful in distinguishing these species taxonomically. This site provides additional evidence of gregarious behavior in ornithomimids and the first probable record of that behavior in North American forms.

DIAGNOSIS AND SUCCESSFUL TREATMENT OF A POTENTIALLY ZOONOTIC DERMATOPHYTOSIS CAUSED BY MICROSPORUM GYPSEUM IN A ZOO-HOUSED NORTH AMERICAN PORCUPINE (ERETHIZON DORSATUM).

PubMed

Hackworth, Christine E; Eshar, David; Nau, Melissa; Bagladi-Swanson, Mary; Andrews, Gordon A; Carpenter, James W

2017-06-01

A female North American porcupine ( Erethizon dorsatum ) was evaluated for a unilateral pedal crusting and alopecic dermatopathy. Fungal culture and histopathology testing revealed Microsporum gypseum dermatophytosis. Treatment with topical miconazole was initiated and then discontinued after 9 days and changed to oral terbinafine. Twenty-eight days after initial examination, clinical signs were improving, and fungal cultures of the front foot, muzzle, and noninfected area along the dorsum were negative for M. gypseum. Visual exams were conducted on a regular basis. Eighty-three days after initial evaluation, clinical signs had completely resolved and repeat fungal cultures were negative. One of the animal's keepers was suspected to have acquired a dermal fungal infection 3 days after contact with this porcupine, and lesions had resolved after treatment with topical ketoconazole. To the authors' knowledge, this is the first report of M. gypseum diagnosed and treated in a captive North American porcupine. Veterinary staff and zookeepers should be aware of this potentially zoonotic infection.

STS-40 Mission Specialist (MS) Seddon on ergometer conducts Exp. No. 066

NASA Image and Video Library

1991-06-14

STS040-211-019 (5-14 June 1991) --- Astride the bicycle ergometer, astronaut Rhea Seddon, mission specialist, breathes into the cardiovascular re-breathing unit during the exercise phase of an experiment. The investigation, In-flight Study of Cardiovascular Deconditioning (Experiment 066), was developed by Dr. Leon E. Farhi of the State University of New York in Buffalo. It focuses on the deconditioning of the heart and lungs and changes in cardiopulmonary function that occur upon return to Earth. By using non-invasive techniques of prolonged expiration and re-breathing, investigators can determine the amount of blood pumped out of the heart (cardiac output), the ease with which blood flows through all the vessels (total peripheral resistance), oxygen used and carbon dioxide released by the body, and lung function and volume changes. Measurements are made both while crew members are resting and while they pedal the exercise bicycle, as Dr. Seddon is doing here. This scene was photographed with a 35mm camera.

A gigantic new dinosaur from Argentina and the evolution of the sauropod hind foot

PubMed Central

González Riga, Bernardo J.; Lamanna, Matthew C.; Ortiz David, Leonardo D.; Calvo, Jorge O.; Coria, Juan P.

2016-01-01

Titanosauria is an exceptionally diverse, globally-distributed clade of sauropod dinosaurs that includes the largest known land animals. Knowledge of titanosaurian pedal structure is critical to understanding the stance and locomotion of these enormous herbivores and, by extension, gigantic terrestrial vertebrates as a whole. However, completely preserved pedes are extremely rare among Titanosauria, especially as regards the truly giant members of the group. Here we describe Notocolossus gonzalezparejasi gen. et sp. nov. from the Upper Cretaceous of Mendoza Province, Argentina. With a powerfully-constructed humerus 1.76 m in length, Notocolossus is one of the largest known dinosaurs. Furthermore, the complete pes of the new taxon exhibits a strikingly compact, homogeneous metatarsus—seemingly adapted for bearing extraordinary weight—and truncated unguals, morphologies that are otherwise unknown in Sauropoda. The pes underwent a near-progressive reduction in the number of phalanges along the line to derived titanosaurs, eventually resulting in the reduced hind foot of these sauropods. PMID:26777391

Recruitment of the Rhesus soleus and medial gastrocnemius before, during and after spaceflight

NASA Technical Reports Server (NTRS)

Roy, R. R.; Hodgson, J. A.; Aragon, J.; Day, M. K.; Kozlovskaya, I.; Edgerton, V. R.

1996-01-01

Electromyograms were recorded from the soleus and medial gastrocnemius muscles and tendon force from the medial gastrocnemius muscle of 2 juvenile Rhesus monkeys before, during and after Cosmos flight 2229 and of ground control animals. Recording sessions were made while the Rhesus were performing a foot pedal motor task. Preflight testing indicated normal patterns of recruitment between the soleus and medial gastrocnemius, i.e. a higher level of recruitment of the soleus compared to the medial gastrocnemius during the task. Recording began two days into the spaceflight and showed that the media gastrocnemius was recruited preferentially over the soleus. This observation persisted throughout the flight and for the 2 week period of postflight testing. These data indicate a significant change in the relative recruitment of slow and fast extensor muscles under microgravity conditions. The appearance of clonic-like activity in one muscle of each Rhesus during flight further suggests a reorganization in the neuromotor system in a microgravity environment.

[The effect of sensory stimuli of varying modality on the human body functioning and indices of tense muscular activity].

PubMed

Kaĭdalin, V S; Kamchatnikov, A G; Sentiabrev, N N; Katuntsev, V P

2007-01-01

The work had a purpose to study benefits of aromatic blends of tonic and relaxing essences and functional music on some of the psychophysiological properties of the human functional state and motor activeity. Participants were 30 sprinters (18-22 y.o. males) having the first-class and master ranks. The psychophysiological indices of the athletes' functional state were evaluated with the use of the "CAH" and Spilberger situational anxiety tests, calculated Cardeu vegetative index, time for simple motor reaction and reaction to a moving object. Motor activity was evaluated by top running speed determined with a photo-electronic time-keeper and by duration of pedaling on bicycle ergometer at maximal power. The running step parameters were recorded with electropodography. It was shown that the positive effect of the aromatic essence blends and functional music on motor activity developed fairly rapidly but did not last long. The article discusses features and possible ways the aromatic blends and music effect human organism.