Faculty Advisor

Nicole Dawson, DPT, PT, PhD

Publication Date

Spring 2021

Abstract

Falls are a leading cause of injury-related deaths in older adults. Although gait speed (a strong predictor of falls) correlates with handgrip strength, its correlation with muscle power (amount of force produced over time) is unknown. Since peak quadriceps rate of force development (RFD) occurs at a submaximal force during ambulation, RFD could be a determinant of gait speed13. Quadriceps RFD is a measure of lower extremity power13, just as handgrip RFD is a measure of upper extremity power. Assuming that RFD is uniform throughout the body, handgrip RFD may also be correlated with gait speed. One method of studying neural input during the initial portion of muscle activation in RFD is through analyzing the rate of electromyography rise (RER) for a specific muscle12.

PURPOSE: To determine whether rate of EMG rise in the flexor carpi radialis muscle (RERFCR) correlates with comfortable gait speed in college-aged adults.

METHODS: Surface EMG was placed over the right flexor carpi radialis (FCR) to measure handgrip RERFCR from 0 to 75 ms. Gait speed was determined through the 4-Meter Walk Test.

RESULTS: There is a significant, positive correlation (p < 0.01) between comfortable gait speed and RERFCR.

CONCLUSION: The results show that motor neuron discharge rate plays a role in gait speed. This does not translate to an ability to predict performance on gait speed tasks or assessment of fall risk, but rather serves as a baseline for future investigation to determine whether muscular power contributes to gait speed.

Comments

Abbreviations: electromyography (EMG), rate of electromyographic rise (RER), flexor carpi radialis (FCR), rate of force development (RFD), National Institute of Health (NIH), first dorsal interosseous (FDI)

Access Status

Open Access

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