Handgrip strength asymmetry is associated with future falls in older Americans

Background Examining handgrip strength (HGS) asymmetry could extend the utility of handgrip dynamometers for screening future falls. Aims We sought to determine the associations of HGS asymmetry on future falls in older Americans. Methods The analytic sample included 10,446 adults aged at least 65 years from the 2006-2016 waves of the Health and Retirement Study. Falls were self-reported. A handgrip dynamometer measured HGS. The highest HGS on each hand was used for determining HGS asymmetry ratio: (non-dominant HGS/dominant HGS). Those with HGS asymmetry ratio < 1.0 had their ratio inverted to make all HGS asymmetry ratios >= 1.0. Participants were categorized into asymmetry groups based on their inverted HGS asymmetry ratio: (1) 0.0-10.0%, (2) 10.1-20.0%, (3) 20.1-30.0%, and (4) > 30.0%. Generalized estimating equations were used for the analyses. Results Every 0.10 increase in HGS asymmetry ratio was associated with 1.26 (95% confidence interval (CI) 1.07-1.48) greater odds for future falls. Relative to those with HGS asymmetry 0.0-10.0%, participants with HGS asymmetry > 30.0% had 1.15 (CI 1.01-1.33) greater odds for future falls; however, the associations were not significant for those with HGS asymmetry 10.1-20.0% (odds ratio: 1.06; CI 0.98-1.14) and 20.1-30.0% (odds ratio: 1.10; CI 0.99-1.22). Compared to those with HGS asymmetry 0.0-10.0%, participants with HGS asymmetry > 10.0% and > 20.0% had 1.07 (CI 1.01-1.16) and 1.12 (CI 1.02-1.22) greater odds for future falls, respectively. Discussion Asymmetric HGS, as a possible biomarker of impaired neuromuscular function, may help predict falls. Conclusions We recommend that HGS asymmetry be considered in HGS protocols and fall risk assessments.