Effects of Knee Extensor Muscle Fatigue on Gait Ability in Patients with Chronic Stroke.

This pilot study examined whether ischemic conditioning (IC), a noninvasive, cost-effective, and easy-to-administer intervention, could improve gait speed and paretic leg muscle function in stroke survivors. We hypothesized that 2 wk of IC training would increase self-selected walking speed, increase paretic muscle strength, and reduce neuromuscular fatigability in chronic stroke survivors. Twenty-two chronic stroke survivors received either IC or IC Sham on their paretic leg every other day for 2 wk (7 total sessions). IC involved 5-min bouts of ischemia, repeated five times, using a cuff inflated to 225 mmHg on the paretic thigh. For IC Sham, the cuff inflation pressure was 10 mmHg. Self-selected walking speed was assessed using the 10-m walk test, and paretic leg knee extensor strength and fatigability were assessed using a Biodex dynamometer. Self-selected walking speed increased in the IC group (0.86 ± 0.21 m/s pretest vs. 1.04 ± 0.22 m/s posttest, means ± SD; P < 0.001) but not in the IC Sham group (0.92 ± 0.47 m/s pretest vs. 0.96 ± 0.46 m/s posttest; P = 0.25). Paretic leg maximum voluntary contractions were unchanged in both groups (103 ± 57 N·m pre-IC vs. 109 ± 65 N·m post-IC; 103 ± 59 N·m pre-IC Sham vs. 108 ± 67 N·m post-IC Sham; P = 0.81); however, participants in the IC group maintained a submaximal isometric contraction longer than participants in the IC Sham group (278 ± 163 s pre-IC vs. 496 ± 313 s post-IC, P = 0.004; 397 ± 203 s pre-IC Sham vs. 355 ± 195 s post-IC Sham; P = 0.46). The results from this pilot study thus indicate that IC training has the potential to improve walking speed and paretic muscle fatigue resistance poststroke. NEW & NOTEWORTHY This pilot study is the first to demonstrate that ischemic conditioning can improve self-selected walking speed and reduce paretic muscle fatigue in stroke survivors. Ischemic conditioning has been shown to be safe in numerous patient populations, can be accomplished at home or at the bedside in only 45 min, and requires no specialized training. Future larger studies are warranted to determine the efficacy of ischemic conditioning as a neurorehabilitation therapy poststroke.

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Determining the cut-off value for knee extensor strength for identifying independence in gait in chronic stroke survivors

Journal of Rehabilitation Medicine ◽

10.2340/16501977-2279 ◽

2017 ◽

Vol 49 (9) ◽

pp. 765-767 ◽

Cited By ~ 4

Author(s):

N Akazawa ◽

N Okawa ◽

K Tamura ◽

H Moriyama

Keyword(s):

Knee Extensor ◽

Chronic Stroke ◽

Stroke Survivors ◽

Knee Extensor Strength

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Knee Extensor Muscle Strength And The Depressive Status Among Older Japanese Women: A Cross-sectional Study

Medicine & Science in Sports & Exercise ◽

10.1249/01.mss.0000761356.47948.d8 ◽

2021 ◽

Vol 53 (8S) ◽

pp. 196-197

Author(s):

Ohta Takahisa ◽

Hiroyuki Sasai ◽

Narumi Kojima ◽

Yosuke Osuka ◽

Kiyoji Tanaka ◽

...

Keyword(s):

Muscle Strength ◽

Knee Extensor ◽

Cross Sectional Study ◽

Japanese Women ◽

Extensor Muscle ◽

Sectional Study ◽

Cross Sectional ◽

Knee Extensor Muscle Strength

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Abstract TP150: Two Weeks of Ischemic Preconditioning Training on the Paretic Leg Improves Leg Strength and Delays Muscle Fatigue in Chronic Stroke

Stroke ◽

10.1161/str.48.suppl_1.tp150 ◽

2017 ◽

Vol 48 (suppl_1) ◽

Author(s):

Matthew J Durand ◽

Spencer A Murphy ◽

Brian D Schmit ◽

David D Gutterman ◽

Allison S Hyngstrom

Keyword(s):

Motor Function ◽

Ischemic Preconditioning ◽

Vascular Function ◽

Knee Extensor ◽

Chronic Stroke ◽

Muscle Performance ◽

Walking Ability ◽

Post Stroke ◽

Leg Strength ◽

Improve Motor Function

Introduction: Individuals living with chronic stroke have weakness and increased neuromuscular fatigue in the paretic leg, which can limit walking ability and endurance. In cardiac and healthy populations, ischemic preconditioning (IPC) is a widely studied, effective, non-invasive stimulus which not only improves vascular function, but also motor performance. IPC occurs when the tissue of interest is exposed to repeated, short bouts of ischemia, which can improve motor function by enhancing vascular, neural and muscle function. IPC has not been tested as a method to improve motor function in individuals post-stroke. Hypothesis: Two weeks of IPC training on the paretic leg will improve leg strength and time-to-task failure (TTF) during a fatiguing muscle contraction. Methods: A feasibility study of 4 individuals (3 female, 1 male) with chronic stroke (20 ± 4 years) was conducted. A Biodex dynamometer was used to assess paretic leg knee extensor maximal voluntary contraction (MVC). To assess muscle fatigability, subjects maintained a sustained contraction equal to 30% of their MVC until failure using visual feedback. After baseline testing, subjects made six visits to the laboratory over a two week period to have IPC performed on their paretic leg. A blood pressure cuff was inflated on the thigh to 225 mmHg for five, five-minute bouts per session. Five minutes of rest was given between inflation cycles. After the last session, subjects returned within 48 hours to have MVC and TTF reassessed. Results: Three subjects completed all study procedures. One subject withdrew for medical reasons unrelated to the study. The IPC procedure was well tolerated by all subjects. After two-week IPC training, knee extensor MVC increased in the paretic leg (45.0 ± 2.7 Nm vs. 52.6 ± 5.7 Nm). Fatigability of the muscles was dramatically reduced after IPC training as TTF tripled (359 ± 180 seconds vs. 1097 ± 343 seconds). Conclusions: We are the first group to show that IPC is a well-tolerated and effective stimulus to improve paretic leg strength and reduce muscle fatigability in subjects with chronic stroke. The results of this pilot study warrant a larger study to determine whether IPC improves muscle performance post-stroke through neural, vascular, or muscle-related mechanisms.

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