Handgrip strength and asymmetry are associated with lower-body muscle power in older women.

Background: The difference in strength between hands, as characterized by handgrip asymmetry, has been shown to be significantly associated with several adverse health outcomes. Handgrip strength asymmetry and its relationship with lower-body muscle power in older adults is not well understood. This study aimed to determine if handgrip strength and asymmetry are associated with lower-body muscle power in older women.

Methods: Twenty active older women (67±5 years) participated in this study. Handgrip contractions were performed with the dominant and non-dominant hand to assess strength measurements of peak force, peak rate of force development (RFD), and RFD at 0-100 (RFD100) and 0-200 (RFD200) ms. Asymmetry ratios were used to determine the severity of differences in handgrip peak force and RFD measurements between the dominant and non-dominant hand. Lower-body peak muscle power was assessed from a vertical jump test.

Results: All handgrip peak force and RFD measurements for the dominant and non-dominant hands were significantly associated with vertical jump peak power (r=0.445-0.547, P=0.013-0.049). Significant correlations were observed between vertical jump peak power and handgrip asymmetry ratios for peak RFD (r=-0.460, P=0.041) and RFD100 (r=-0.591, P=0.006). Multiple regression analysis indicated that handgrip RFD100 asymmetry ratio and RFD200 for the dominant hand were significant predictors of vertical jump peak power, and together, explained 53.9% of its variance.

Conclusions: These findings suggest that handgrip RFD and asymmetry may be effective measurements at predicting lower-body muscle power in older women.