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

2017 ◽  
Vol 49 (9) ◽  
pp. 765-767 ◽  
Author(s):  
N Akazawa ◽  
N Okawa ◽  
K Tamura ◽  
H Moriyama
Keyword(s):  
Knee Extensor ◽  
Chronic Stroke ◽  
Stroke Survivors ◽  
Knee Extensor Strength

scholarly journals Ischemic conditioning increases strength and volitional activation of paretic muscle in chronic stroke: a pilot study

2018 ◽  
Vol 124 (5) ◽  
pp. 1140-1147 ◽  
Author(s):  
Allison S. Hyngstrom ◽  
Spencer A. Murphy ◽  
Jennifer Nguyen ◽  
Brian D. Schmit ◽  
Francesco Negro ◽  
...  
Keyword(s):  
Motor Unit ◽  
Muscle Activation ◽  
Knee Extensor ◽  
Chronic Stroke ◽  
Motor Unit Recruitment ◽  
Stroke Survivors ◽  
Single Session ◽  
Ischemic Conditioning ◽  
Leg Strength ◽  
Knee Extensor Strength

Ischemic conditioning (IC) on the arm or leg has emerged as an intervention to improve strength and performance in healthy populations, but the effects on neurological populations are unknown. The purpose of this study was to quantify the effects of a single session of IC on knee extensor strength and muscle activation in chronic stroke survivors. Maximal knee extensor torque measurements and surface EMG were quantified in 10 chronic stroke survivors (>1 yr poststroke) with hemiparesis before and after a single session of IC or sham on the paretic leg. IC consisted of 5 min of compression with a proximal thigh cuff (inflation pressure = 225 mmHg for IC or 25 mmHg for sham) followed by 5 min of rest. This was repeated five times. Maximal knee extensor strength, EMG magnitude, and motor unit firing behavior were measured before and immediately after IC or sham. IC increased paretic leg strength by 10.6 ± 8.5 Nm, whereas no difference was observed in the sham group (change in sham = 1.3 ± 2.9 Nm, P = 0.001 IC vs. sham). IC-induced increases in strength were accompanied by a 31 ± 15% increase in the magnitude of muscle EMG during maximal contractions and a 5% decrease in motor unit recruitment thresholds during submaximal contractions. Individuals who had the most asymmetry in strength between their paretic and nonparetic legs had the largest increases in strength ( r2 = 0.54). This study provides evidence that a single session of IC can increase strength through improved muscle activation in chronic stroke survivors. NEW & NOTEWORTHY Present rehabilitation strategies for chronic stroke survivors do not optimally activate paretic muscle, and this limits potential strength gains. Ischemic conditioning of a limb has emerged as an effective strategy to improve muscle performance in healthy individuals but has never been tested in neurological populations. In this study, we show that ischemic conditioning on the paretic leg of chronic stroke survivors can increase leg strength and muscle activation while reducing motor unit recruitment thresholds.

scholarly journals Corticospinal tract integrity correlates with knee extensor weakness in chronic stroke survivors

2011 ◽  
Vol 122 (8) ◽  
pp. 1588-1594 ◽  
Author(s):  
Sangeetha Madhavan ◽  
Chandramouli Krishnan ◽  
Arun Jayaraman ◽  
William Z. Rymer ◽  
James W. Stinear
Keyword(s):  
Corticospinal Tract ◽  
Knee Extensor ◽  
Chronic Stroke ◽  
Stroke Survivors

scholarly journals Two weeks of ischemic conditioning improves walking speed and reduces neuromuscular fatigability in chronic stroke survivors

2019 ◽  
Vol 126 (3) ◽  
pp. 755-763 ◽  
Author(s):  
Matthew J. Durand ◽  
Timothy F. Boerger ◽  
Jennifer N. Nguyen ◽  
Saad Z. Alqahtani ◽  
Michael T. Wright ◽  
...  
Keyword(s):  
Pilot Study ◽  
Muscle Fatigue ◽  
Sham Group ◽  
Walking Speed ◽  
Knee Extensor ◽  
Cost Effective ◽  
Chronic Stroke ◽  
Stroke Survivors ◽  
Speed Increase ◽  
Ischemic Conditioning

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.

Aerobic locomotor exercise modulates brain activation patterns in chronic stroke survivors

2005 ◽  
Vol 32 (S 4) ◽  
Author(s):  
A.R Luft ◽  
L Forrester ◽  
F Villagra ◽  
R Macko ◽  
D.F Hanley
Keyword(s):  
Brain Activation ◽  
Chronic Stroke ◽  
Stroke Survivors ◽  
Activation Patterns

scholarly journals Efficacy of cardiac rehabilitation with motion assistance from wearable cyborg hybrid assistive limb in patients with chronic heart failure: a randomized controlled trial

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
H Watanabe ◽  
A Koike ◽  
H Kato ◽  
L Wu ◽  
K Hayashi ◽  
...  
Keyword(s):  
Heart Failure ◽  
Chronic Heart Failure ◽  
Cardiac Rehabilitation ◽  
Exercise Therapy ◽  
Knee Extensor ◽  
Control Group ◽  
Cardiac Events ◽  
Rehabilitation Programs ◽  
Sit To Stand ◽  
Knee Extensor Strength

Abstract Background Recent Cochrane Systematic Review suggested that the participation in cardiac rehabilitation is associated with approximately 20% lower cardiovascular mortality and morbidity. Exercise therapy is the key component of cardiac rehabilitation programs. In recent years, innovative technologies have been introduced into the field of rehabilitation, and a typical example is the wearable cyborg Hybrid Assistive Limb (HAL). The wearable cyborg HAL provides motion assistance based on detection of bioelectrical signals on the skin surface when muscle forces are generated. The lumbar-type HAL is expected to expand the therapeutic options for severe cardiac patients who have difficulty in performing usual cardiac rehabilitation programs, such as bicycle pedaling or walking. Purpose We aim to compare the efficacy of exercise therapy performed with motion assistance from a lumbar-type HAL versus conventional training (sit-to-stand exercise without HAL) in patients with chronic heart failure. Methods This clinical trial is a randomized, non-blinded, and controlled study. Twenty-eight heart failure patients (73.1±13.8 years) who have difficulty in walking at the usual walking speed of healthy subjects were randomly assigned to 2 groups (HAL group or control group) with a 1:1 allocation ratio and performed sit-to stand exercise either with HAL or without HAL for 5 to 30 minutes once a day, and 6 to 10 days during the study period. The brain natriuretic peptide (BNP), isometric knee extensor strength, standing ability (30-seconds chair-stand test: CS-30), short physical performance battery (SPPB) and 6-minute walking distance (6MWD) were measured before and after the completion of cardiac rehabilitation. Cardiac events such as death, re-hospitalization, myocardial infarction and worsening of angina pectoris and heart failure during 1 year after discharge were evaluated. Results There was no significant difference in the number of days of exercise therapy between the two groups. BNP, SPPB and 6MWD were improved in both groups. In the HAL group, the isometric knee extensor strength (0.29±0.11 vs 0.35±0.11 kgf/kg, p=0.003) significantly improved and CS-30 (5.5±5.1 vs 8.2±5.3, p=0.054) tended to improve. However, in the control group, either the isometric knee extensor strength (0.35±0.11 vs 0.36±0.14 kgf/kg, p=0.424) or CS-30 (6.0±4.3 vs 9.2±6.2, p=0.075) did not significantly change. HAL group showed significantly more improvement in the isometric knee extensor strength than control group (p=0.045). Cardiac events occurred in 20% in the HAL group and 43% in the control group. Conclusion The improvement in isometric knee extensor strength with the assistance from lumbar-type HAL suggests that exercise therapy using this device may be useful in chronic heart failure patients with flail or sarcopenia, a strong poor prognostic factor in these patients. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): This work was supported in part by a grant-in-aid for Scientific Research from the Ministry of Education, Science, and Culture of Japan (JSPS KAKENHI grant number JP17K09485) and funded by the ImPACT Program of the Council for Science, Technology and Innovation (Cabinet Office, Government of Japan) (grant number 2017-PM05-03-01).

scholarly journals Alterations in Muscle Networks in the Upper Extremity of Chronic Stroke Survivors

2021 ◽  
pp. 1-1
Author(s):  
Michael Houston ◽  
Xiaoyan Li ◽  
Ping Zhou ◽  
Sheng Lia ◽  
Jinsook Roh ◽  
...  
Keyword(s):  
Upper Extremity ◽  
Chronic Stroke ◽  
Stroke Survivors
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