What are we measuring? An examination of walk time and grip strength

Are walk time and grip strength measures of disease activity or functional ability? Ninety-two patients with rheumatoid arthritis were examined initially and 12 months later for clinical measures including joint deformity, and answered a functional status questionnaire. Walk time and grip strength were strongly related to joint deformity and functional questionnaire measures, and appeared insensitive in showing changes in disease activity over time. They could serve as objective functional measures in studies primarily directed towards changing functional ability, but appeared to be poor major outcome measures for trials aimed at altering disease activity.