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Updated: Dec 25, 2025
Quantifying Arms and Legs Contributions during Repetitive Electrically-Assisted Sit-To-Stand Exercise in Paraplegics: A Pilot Study
Published on: November 11, 2022
Lower limb muscle fatigability is not associated with changes in movement strategies for balance control in the
Patricia Sant'Anna do Carmo Aprigio1, Igor Ramathur Telles de Jesus2, Carla Porto2
1Postgraduate Program of Rehabilitation Sciences, Centro Universitário Augusto Motta (UNISUAM), Rio de Janeiro, RJ, Brazil; Laboratório de Pesquisa em Ciências do Exercício (LABOCE), Centro de Educação Física Almirante Adalberto Nunes (CEFAN), Rio de Janeiro, Brazil.
Background:
Fatigue is a distressing symptom inversely related to postural stability in adults with neuromuscular and systemic diseases. However, there is no information about the effects of lower limb muscles fatigability on the movement strategies for balance control in the upright standing.
Methods:
This study enrolled 41 healthy subjects (female/male: 22/19; age 23 ± 3 years; body mass index 25.4 ± 3.7 kg/m2). Participants underwent posturography and surface electromyography of the gastrocnemius medialis muscle during a sustained, fatiguing voluntary contraction of the gastrocnemius preceded and followed by quiet standing (120 s). Amplitude of electromyograms and fatigability were evaluated using the root mean square (RMS) value and both the RMS and spectral median frequency (fmed) slopes. Balance control was evaluated using the center-of-pressure elliptic area (Area) and average velocity (Vavg). Movement strategies for balance control were evaluated using the number of high-density regions (nHDR) and spatial patterns of the three-dimensional statokinesigram.
Results:
Mean time to muscle fatigability was 258 ± 190 s. Area and Vavg but not nHDR increased after the fatiguing task. Single-centered spatial patterns were predominant in both tasks (pre-fatigue: n = 22/41; post-fatigue: n = 19/41), with no evidence of an association between the spatial patterns and tasks (γ = 0.237, 95%CI = [-0.338; 0.542]).
Conclusions:
Lower limb muscle fatigability increases postural instability, but it is not associated with changes in movement strategies for balance control in the upright stance.
