Reliability of handgrip strength test in elderly subjects with unilateral thumb carpometacarpal osteoarthritis

Background The grip strength test is widely used; however, little has been investigated about its reliability when used in elderly with subjects thumb carpometacarpal (CMC) osteoarthritis (OA). The purpose of this study was to examine the test–retest reliability of the grip strength test in elderly subjects with thumb CMC OA. Methods A total of 78 patients with unilateral thumb CMC OA, 84.6%female (mean±SD age 83±5 years), were recruited. Each patient performed three pain free maximal isometric contractions on each hand in two occasions, 1 week apart. Intraclass correlation coefficient (ICC), standard error of measurement (SEM), and 95 % limits of agreement (LOA) were calculated. Results Test–retest reliability was excellent for side affected (ICC=0.947; p=0.001) and contralateral (ICC=0.96; p=0.001) thumb CMC OA. Conclusions The present results indicate that maximum handgrip strength can be measured reliably, using the Jamar hand dynamometer, in patients with thumb CMC OA, which enables its use in research and in the clinic to determine the effect of interventions on improving grip.