The Effects of Calf Muscle Length on Local Muscle Fatigability (2024)

Undergraduate: Anh Nguyen

Faculty Advisor: Jason Franz
Department: Biomedical Engineering

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This study investigates the effects of calf muscle length on local muscle fatigue among a cohort of 16 young adults. We focused on the calf muscles due to their relevance to walking performance and age-related mobility decline. We employed a repeated measures design, utilizing a dynamometer, soleus EMG and medial gastrocnemius ultrasound to test two ankle positions that resulted in different fascicle lengths. Results indicated that shorter fascicle lengths led to a significant increase in muscle activity and a decrease in time to fatigue onset. A modest but significant negative correlation between the decreases in fascicle length and the change in time to onset of fatigue suggests a complex relationship that warrants further exploration. We contend that these findings have clinical relevance for mechanisms associated with mobility impairment among older adults, who often operate their calf muscles at shorter lengths. These insights have practical implications for personalized rehabilitation and training protocols and may help refine ways – such as assistive devices – to mitigate fatigue in older adults.