Differences in muscle synergies between healthy subjects and transfemoral amputees during normal transient-state walking speed

The effects of walking speeds on lower-extremity muscle synergies (MSs) were investigated among 20 adults who walked 20 m at SLOW (0.6 ± 0.2 m/s), natural (NAT; 1.4 ± 0.1 m/s), and FAST (1.9 ± 0.1 m/s) speeds. Surface electromyography of eight lower-extremity muscles was recorded before extracting MSs using a nonnegative matrix factorization algorithm. Increasing walking speed tended to merge MSs associated with weight acceptance and limb deceleration, whereas reducing walking speed does not change the number and composition of MSs. Varying gait speed, particularly decreasing speed, may represent a gait training strategy needing additional attention given its effects on MSs.

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Bilateral vestibulopathy and age: experimental considerations for testing dynamic visual acuity on a treadmill

Journal of Neurology ◽

10.1007/s00415-020-10249-z ◽

2020 ◽

Vol 267 (S1) ◽

pp. 265-272

Author(s):

D. Starkov ◽

M. Snelders ◽

F. Lucieer ◽

A. M. L. Janssen ◽

M. Pleshkov ◽

...

Keyword(s):

Visual Acuity ◽

Healthy Subjects ◽

Walking Speed ◽

Static Condition ◽

Drop Out ◽

Dynamic Visual Acuity ◽

Bilateral Vestibulopathy ◽

Drop Out Rate ◽

Visual Acuity Loss ◽

Walking Speeds

Abstract Introduction Bilateral vestibulopathy (BVP) can affect visual acuity in dynamic conditions, like walking. This can be assessed by testing Dynamic Visual Acuity (DVA) on a treadmill at different walking speeds. Apart from BVP, age itself might influence DVA and the ability to complete the test. The objective of this study was to investigate whether DVA tested while walking, and the drop-out rate (the inability to complete all walking speeds of the test) are significantly influenced by age in BVP-patients and healthy subjects. Methods Forty-four BVP-patients (20 male, mean age 59 years) and 63 healthy subjects (27 male, mean age 46 years) performed the DVA test on a treadmill at 0 (static condition), 2, 4 and 6 km/h (dynamic conditions). The dynamic visual acuity loss was calculated as the difference between visual acuity in the static condition and visual acuity in each walking condition. The dependency of the drop-out rate and dynamic visual acuity loss on BVP and age was investigated at all walking speeds, as well as the dependency of dynamic visual acuity loss on speed. Results Age and BVP significantly increased the drop-out rate (p ≤ 0.038). A significantly higher dynamic visual acuity loss was found at all speeds in BVP-patients compared to healthy subjects (p < 0.001). Age showed no effect on dynamic visual acuity loss in both groups. In BVP-patients, increasing walking speeds resulted in higher dynamic visual acuity loss (p ≤ 0.036). Conclusion DVA tested while walking on a treadmill, is one of the few “close to reality” functional outcome measures of vestibular function in the vertical plane. It is able to demonstrate significant loss of DVA in bilateral vestibulopathy patients. However, since bilateral vestibulopathy and age significantly increase the drop-out rate at faster walking speeds, it is recommended to use age-matched controls. Furthermore, it could be considered to use an individual “preferred” walking speed and to limit maximum walking speed in older subjects when testing DVA on a treadmill.

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Feasibility of error-based electrotactile and auditive feedback in prosthetic walking

Prosthetics and Orthotics International ◽

10.1177/0309364613520319 ◽

2014 ◽

Vol 39 (3) ◽

pp. 255-259 ◽

Cited By ~ 5

Author(s):

Eva C Wentink ◽

Eline J Talsma-Kerkdijk ◽

Hans S Rietman ◽

Peter Veltink

Keyword(s):

Reaction Time ◽

Auditory Feedback ◽

Healthy Subjects ◽

Swing Phase ◽

Feedback Condition ◽

Practical Applications ◽

Undesired Event ◽

Transfemoral Amputees ◽

Giving Feedback ◽

Leg Prosthesis

Background and aim: Several studies have shown that feedback in upper-leg prostheses is possible, but slow or difficult to interpret. In this study, electrotactile and auditive error-based feedback, only giving feedback when an undesired event occurs, were tested for its use in upper-leg prosthesis when provided during a perturbation. Technique: A total of nine healthy subjects walked on a prosthetic simulator which was disturbed at the end of the swing phase. They received either no feedback, electrotactile feedback, or auditive feedback at the time of the perturbation. Discussion: The reaction time of the subjects only improved by 40 ms when using auditory feedback, compared to the no-feedback condition. No changes in reaction time were found in the electrotactile feedback condition. Considering perturbation detection was not taken into account in this study, this improvement is not enough for practical applications in upper-leg prosthesis. Clinical relevance Many transfemoral amputees are insecure about their prosthesis, are afraid of falling, or actually fall. Providing feedback specifically during a perturbation may prevent them from falling, or at least give them a chance to react.

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Identification of shoulder muscle synergies in healthy subjects during an isometric task

2017 International Conference on Rehabilitation Robotics (ICORR) ◽

10.1109/icorr.2017.8009235 ◽

2017 ◽

Cited By ~ 1

Author(s):

Aamani Budhota ◽

Paolo Tommasino ◽

Asif Hussain ◽

Domenico Campolo

Keyword(s):

Healthy Subjects ◽

Muscle Synergies ◽

Shoulder Muscle

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The effects of walking speed on upper body kinematics during gait in healthy subjects

Gait & Posture ◽

10.1016/j.gaitpost.2017.03.025 ◽

2017 ◽

Vol 54 ◽

pp. 304-310 ◽

Cited By ~ 15

Author(s):

Jacqueline Romkes ◽

Katrin Bracht-Schweizer

Keyword(s):

Healthy Subjects ◽

Walking Speed ◽

Upper Body

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Influence of walking speed on locomotor time production

10.1101/001156 ◽

2013 ◽

Author(s):

Fabrice MEGROT ◽

Carole MEGROT

Keyword(s):

Healthy Subjects ◽

Walking Speed ◽

The Other ◽

Temporal Perception ◽

Time Production ◽

Fast Walking ◽

Slow Walking ◽

Perception Of Time ◽

Walking Speeds

The aim of the present study was to determine whether or not walking speed affects temporal perception. It was hypothesized that fast walking would reduce the perceived length of time while slow walking increase production estimates. 16 healthy subjects were included. After a first « calibration » phase allowing the determination of different walking speeds, the subjects were instructed to demonstrate periods of time or « target times » of 3s and 7s, by a walking movement. Then, subjects were asked to simulate walking by raising one foot after the other without advancing. Finally, a third condition, Motionless, involved producing the target times while standing without movement. The results of this study suggest that movement does influence the perception of time, causing an overestimation of time. In agreement with the results of Denner et al. (1963) the subjects produced times which were longer than the target times.

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The Relationship Between Walking Speed and the Energetic Cost of Walking in Persons With Multiple Sclerosis and Healthy Controls: A Systematic Review

Neurorehabilitation and Neural Repair ◽

10.1177/15459683211005028 ◽

2021 ◽

pp. 154596832110050

Author(s):

Kyra Theunissen ◽

Guy Plasqui ◽

Annelies Boonen ◽

Bente Brauwers ◽

Annick Timmermans ◽

...

Keyword(s):

Multiple Sclerosis ◽

Healthy Subjects ◽

Walking Speed ◽

Included Study ◽

Treadmill Walking ◽

Energetic Cost ◽

Overground Walking ◽

Blood Institute ◽

National Heart Lung ◽

The Relationship

Background Persons with multiple sclerosis (pwMS) experience walking impairments, characterized by decreased walking speeds. In healthy subjects, the self-selected walking speed is the energetically most optimal. In pwMS, the energetically most optimal walking speed remains underexposed. Therefore, this review aimed to determine the relationship between walking speed and energetic cost of walking (Cw) in pwMS, compared with healthy subjects, thereby assessing the walking speed with the lowest energetic cost. As it is unclear whether the Cw in pwMS differs between overground and treadmill walking, as reported in healthy subjects, a second review aim was to compare both conditions. Method PubMed and Web of Science were systematically searched. Studies assessing pwMS, reporting walking speed (converted to meters per second), and reporting oxygen consumption were included. Study quality was assessed with a modified National Heart, Lung and Blood Institute checklist. The relationship between Cw and walking speed was calculated with a second-order polynomial function and compared between groups and conditions. Results Twenty-nine studies were included (n = 1535 pwMS) of which 8 included healthy subjects (n = 179 healthy subjects). PwMS showed a similar energetically most optimal walking speed of 1.44 m/s with a Cw of 0.16, compared with 0.14 mL O2/kg/m in healthy subjects. The most optimal walking speed in treadmill was 1.48 m/s, compared with 1.28 m/s in overground walking with a similar Cw. Conclusion Overall, the Cw is elevated in pwMS but with a similar energetically most optimal walking speed, compared with healthy subjects. Treadmill walking showed a similar most optimal Cw but a higher speed, compared with overground walking.

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