Handgrip Measurement Method Affects Asymmetry but Not Weakness Identification in Community-Dwelling Older Adults.

Abstract

The Asian Working Group for Sarcopenia (AWGS) 2019 recommends different measurement protocols for handgrip strength (HGS). We aimed to explore (1) whether these protocols induce a significant difference in HGS; (2) whether these differences be clinically meaningful; and (3) whether these protocols affect the identification of HGS weakness or asymmetry. Cross-sectional study. A total of 356 community-dwelling older adults (mean age 67.9years; 146 women). Maximal HGS was measured according to protocols from the National Health and Nutrition Examination Survey (Method A, standing with full elbow extended) and the American Society of Hand Therapists (Method B, sitting with elbow flexed at 90°). HGS was analyzed using the maximal value of 2 or 3 repetitions of the dominant hand or 4 or 6 repetitions of both hands. The difference in maximal HGS between Method A and Method B might have clinical meaning in approximately half of the participants. When measured using Method A, respective proportions of individuals with differences in HGS between the 6 repetitions group and the other repetition groups beyond the noninferiority threshold were 42%, 20%, and 25% in men and 39%, 21%, and 17% in women. Using Method B, the corresponding percentages were 25%, 18%, and 6% in men, and 27%, 20%, and 5% in women, respectively. Different protocols did not significantly affect the identification of HGS weakness, as different protocols reached diagnostic accuracies of 0.910 to 0.967 in men and 0.911 to 0.986 in women when using Method A (6 repetitions) as the reference standard. However, different protocols significantly affected the identification of HGS asymmetry, as different protocols had diagnostic accuracies of 0.667 to 0.886 in men and 0.658 to 0.863 in women. The different protocols recommended by the AWGS 2019 update significantly affect maximal HGS values and the identification of HGS asymmetry but not HGS weakness.