Quantification of Muscular Demands in the Elderly: Electromyography vs. Joint Moments
Chen, Chu Jui, 1981-
This study was performed to evaluate the sensitivity of using electromyography (EMG) and joint moment to quantify muscular challenges in elderly adults. Twenty elderly and young adults walked on level ground and crossed an obstacle. Resultant hip, knee, and ankle joint moments and EMG data from muscles of the dominant leg were analyzed. Older adults demonstrated significantly greater normalized EMG (N-EMG) magnitudes than young adults in most muscles. However, only hip abductor moment demonstrated significant group differences. Stepping over a higher obstacle resulted in greater N-EMG magnitudes in all muscles. Leading limb knee extensor moment was found to significantly decrease with increasing obstacle height, while N-EMGs of knee joint muscles increased. Our findings suggest that N-EMG, which can better account for co-activation of agonist and antagonist muscles, might be a more sensitive parameter than the joint moment in detecting age- and task-related differences.