Handgrip Strength: A Comparison of Values Obtained From the NHANES and NIH Toolbox Studies.

IMPORTANCE: Handgrip dynamometry is probably the most commonly used method to characterize overall human muscle strength. OBJECTIVE: To compare and summarize grip strength measurements obtained from two population-based studies. DESIGN: Secondary data analysis. SETTING AND PARTICIPANTS: Data from (1) the 2011-2014 National Health and Nutrition Examination Survey (NHANES) with 13,918 participants and (2) the 2011 normative phase of the National Institutes of Health (NIH) Toolbox project with 3,594 participants. OUTCOMES AND MEASURES: The NHANES values used were the mean and best of three trials; the NIH Toolbox value used was the one maximum trial after a practice trial. RESULTS: General linear model analysis revealed that values obtained from the NIH Toolbox differed from NHANES best values but not from NHANES mean values. The analysis also indicated, regardless of the values used, that grip strength differed significantly between dominant and nondominant sides, males and females, and age groups. We provide updated reference values for handgrip strength. CONCLUSIONS AND RELEVANCE: On the basis of these analyses, we summarize grip strength measures obtained from the NHANES and NIH Toolbox for side, gender, and age group strata. Reference values are essential to assist in the interpretation of testing results and clinical decision making.