Cut Points for Clinical Muscle Weakness Among Older Americans

Am J Prev Med. 2017 Jul;53(1):63-69. doi: 10.1016/j.amepre.2016.12.022. Epub 2017 Feb 9.


Introduction: Muscle weakness is an important indicator of disability, chronic disease, and early mortality. Grip strength is a simple, cost-effective measure of overall muscle strength. The Foundation of the National Institutes of Health recently proposed sex-specific grip strength cut points for clinical muscle weakness. However, these criteria were established using non-nationally representative data. This study used nationally representative data on Americans aged ≥65 years to identify race- and sex-specific cut points for clinical muscle weakness and quantify prevalence among older blacks and whites by sex.

Methods: Classification and Regression Tree models were used to identify cut points based on individual-level grip strength associated with slow gait speed (<0.8 m/second) among 7,688 individuals (57% female; 8% black; mean age, 74.6 [SD=6.79] years) from the 2010/2012 Health and Retirement Study during January-April 2016. Identified cut points were then used to quantify the prevalence of weakness by race/sex subgroup.

Results: Fifty-five percent of men (maximum grip strength <39 kg) and 47% of women (maximum grip strength <22 kg) were classified as weak. Higher cut points were identified for black men (maximum grip strength <40 kg) and women (maximum grip strength <31 kg), and the prevalence of weakness (57% and 88%, respectively) was higher compared with whites. Fifty-five percent of individuals had slow gait speed (<0.8 m/second).

Conclusions: Prevalence of weakness was substantially higher than previous reports, underscoring the importance of using population-level data to identify individuals at greatest risk for adverse health outcomes. This is the first study to establish cut points for muscle weakness in a nationally representative sample by race and sex.

Publication types

  • Comparative Study

MeSH terms

  • Aged
  • Aged, 80 and over
  • Aging / physiology
  • Cross-Sectional Studies
  • Female
  • Gait
  • Hand Strength / physiology*
  • Humans
  • Male
  • Muscle Weakness / diagnosis*
  • Muscle Weakness / epidemiology*
  • Prevalence
  • Sex Factors
  • United States / epidemiology