Joint impairment and hand function in the elderly.

OBJECTIVE: To test the contribution of joint impairment to observed hand function (grip strength and Williams Test) in the elderly, using a multivariate model. DESIGN: Cross-sectional observational data (baseline data from an ongoing longitudinal study). SUBJECTS: Five hundred forty-one persons over age 60, including continuing care retirement community (n = 222), homebound (n = 72), and ambulatory (n = 247) respondents. Mean age at assessment 76.7, (SD = 9.0). MEASUREMENT: Independent variables included sociodemographics, physician measures of upper joint impairment, an index of comorbidities derived from physical examination or chart abstract, self-assessed arthritis pain, depression, and anxiety. The dependent variables included grip strength and a modified Williams Test [Williams Test (M)]. MAIN RESULTS: The multiple regression explained 59% (Adjusted R2 = .59) of the variance in grip strength, with joint impairment accounting for a change in R2 of .07. Upper joint impairment and grip strength accounted for 3% and 5%, respectively, of the variance in the Williams Test (M) (total amount of explained variance = 45%). CONCLUSIONS: Demographics explain most of the variance in grip strength and performance on the Williams Test (M). Controlling for demographics, musculoskeletal disease represented by joint impairment is associated with diminished grip strength. Reduced grip strength is associated with poorer performance on the Williams Test (M).