scholarly journals The Effect of Lower Extremity Muscle Fatigue on Dynamic Postural Control Analyzed by Electromyography

2016 ◽  
Vol 6 (1) ◽  
pp. 37-50 ◽  
Author(s):  
Majid Fatahi ◽  
Gholam Ali Ghasemi ◽  
Yosef Mongashti Joni ◽  
Vahid Zolaktaf ◽  
Faraj Fatahi ◽  
...  
PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0242963
Author(s):  
Peter M. Wayne ◽  
Brian J. Gow ◽  
Fengzhen Hou ◽  
Yan Ma ◽  
Jeffrey M. Hausdorff ◽  
...  

Background Tai Chi (TC) mind-body exercise has been shown to reduce falls and improve balance and gait, however, few studies have evaluated the role of lower extremity muscle activation patterns in the observed benefits of TC on mobility. Purpose To perform an exploratory analysis of the association between TC training and levels of lower extremity muscle co-contraction in healthy adults during walking under single-task (ST) and cognitive dual-task (DT) conditions. Methods Surface electromyography of the anterior tibialis and lateral gastrocnemius muscles was recorded during 90 sec trials of overground ST (walking normally) and DT (walking with verbalized serial subtractions) walking. A mean co-contraction index (CCI), across all strides, was calculated based on the percentage of total muscle activity when antagonist muscles were simultaneously activated. A hybrid study design investigated long-term effects of TC via a cross-sectional comparison of 27 TC experts and 60 age-matched TC-naïve older adults. A longitudinal comparison assessed the shorter-term effects of TC; TC-naïve participants were randomly allocated to either 6 months of TC training or to usual care. Results Across all participants at baseline, greater CCI was correlated with slower gait speed under DT (β(95% CI) = -26.1(-48.6, -3.7)) but not ST (β(95% CI) = -15.4(-38.2, 7.4)) walking. Linear models adjusting for age, gender, BMI and other factors that differed at baseline indicated that TC experts exhibited lower CCI compared to TC naives under DT, but not ST conditions (ST: mean difference (95% CI) = -7.1(-15.2, 0.97); DT: mean difference (95% CI) = -10.1(-18.1, -2.4)). No differences were observed in CCI for TC-naive adults randomly assigned to 6 months of TC vs. usual care. Conclusion Lower extremity muscle co-contraction may play a role in the observed benefit of longer-term TC training on gait and postural control. Longer-duration and adequately powered randomized trials are needed to evaluate the effect of TC on neuromuscular coordination and its impact on postural control. Trial registration The randomized trial component of this study was registered at ClinicalTrials.gov (NCT01340365).


1999 ◽  
Vol 79 (12) ◽  
pp. 1177-1185 ◽  
Author(s):  
Marguerite Elizabeth Daubney ◽  
Elsie G Culham

Abstract Background and Purpose.Measures of postural control may be useful for determining fall risk in older people and for determining the outcomes of treatments aimed at improving balance. Commonly used tools measure the output of the postural control system. The purpose of this study was to determine the degree to which one component of postural control (muscle force) contributes to scores on 3 functional balance measures. Subjects. Fifty community-dwelling volunteers between 65 and 91 years of age (X̄=74.82, SD=6.11) participated. Based on their histories, 11 subjects were classified as being at risk for falling. Methods. Measures were the Berg Balance Scale (BBS), the Functional Reach Test (FRT), and the Timed Get Up & Go Test (GUG). The force generated by 12 lower-extremity muscle groups was measured using a handheld dynamometer. Results. In the group reporting no falls, dorsiflexor and subtalar evertor force accounted for 58% of the score on the BBS, ankle plantar-flexor and subtalar invertor force accounted for 48.4% of the score on the GUG, and ankle plantar-flexor force accounted for 13% of the score on the FRT. Ankle dorsiflexor and hip extensor forces were lower in subjects reporting falls, and force of the ankle dorsiflexors predicted fall status. Conclusion and Discussion. Distal muscle force measures may be able to contribute to the prediction of functional balance scores; however, the muscles involved in the prediction differ depending on the measure of balance.


2021 ◽  
Vol 19 (1) ◽  
pp. 51-58
Author(s):  
Nastaran Ghotbi ◽  

Objectives: Lower extremity muscles are critical for maintaining dynamic balance and athletic performance. Fatigue of these muscles may affect dynamic balance. It is unclear whether fatigue in a particular muscle group can affect dynamic balance more than that in other groups. This study was conducted to evaluate and compare the effects of fatigue in 5 muscle groups on dynamic balance in volleyball players. Methods: Fifteen healthy male volleyball players separately performed the Star Excursion Balance Test before and immediately after the occurrence of fatigue of ankle Plantar Flexor (PF), knee extensor, knee flexor, hip abductor, and hip adductor muscles. Composite reach distance and distance in anterior, posteromedial, and posterolateral directions were recorded, accordingly. Results: Repeated-measures Analysis of Variance (ANOVA) data indicated that fatigue of all muscle groups significantly decreased the mean score of composite (P<0.001). Anterior, posteromedial, and posterolateral distance scores decreased following muscle fatigue of knee extensors and ankle PFs (P<0.05). Discussion: This study suggested that regarding composite reach score, fatigue of ankle, knee, and hip muscles similarly decreased dynamic balance. However, evaluating three main directions revealed that knee extensors and ankle PFs muscles fatigue presented more prominent effects on the explored volleyball players’ balance, compared to the other muscles.


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