Reliability of Pinch Strength Testing in Elderly Subjects with Unilateral Thumb Carpometacarpal Osteoarthritis

Abstract

[Purpose] The aim of this study was to examine the test-retest reliability of pinch strength testing in elderly subjects with thumb CMC OA. [Subjects and Methods] A total of 27 patients with unilateral right-thumb CMC OA (mean ± SD age: 81.3 ± 4.7 years) were recruited. Each patient performed three pain-free maximal isometric contractions on each hand on two occasions, one week apart. Three different measurements were taken: tip, tripod, and key pinch strength. Intraclass correlation coefficient (ICC), standard error of measurement (SEM), and 95% limits of agreement (LOA) calculations were performed. [Results] Test-retest reliability of measurements of tip, tripod, and key pinch strength was excellent for the affected side (ICC=0.93, 0.96, and 0.99) and the contralateral thumb (ICC=0.91, 0.92, and 0.94). [Conclusions] The present results indicate that maximum pinch strength can be measured reliably using the Pinch Gauge 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 pinch strength.

Weaker Functional Pinch Strength Is Associated With Early Thumb Carpometacarpal Osteoarthritis

“…Pinch positions were defined using the American Society for Hand Therapists guidelines [11,29]. Key pinch was defined as holding the sensor between the pad of the thumb and the radial aspect of the index finger, located approximately near the proximal interphalangeal joint.…”

The Effect of a Bone Tunnel During Ligament Reconstruction for Trapeziometacarpal Osteoarthritis: A 5-Year Follow-up

“…Strength for each patient was recorded as the mean of 3 consecutive measurements. 25,26 All measurements were performed by independent hand therapists who were blinded to the study procedure, in accordance with a strict protocol.…”

CORR Insights®: Reduction in Cylindrical Grasp Strength Is Associated With Early Thumb Carpometacarpal Osteoarthritis

“…Currently, we rely on evaluating pure pinch or pure grip strength as a guide to understanding the deterioration of hand function as the disease progresses. But we still do not know whether these measurements actually reflect the weakness that patients experience during their daily living activities [7,8]. We need better approaches to examining thumb function during daily living activities such as opening jars, getting dressed, or food preparation [8,10].…”

“…But we still do not know whether these measurements actually reflect the weakness that patients experience during their daily living activities [7,8]. We need better approaches to examining thumb function during daily living activities such as opening jars, getting dressed, or food preparation [8,10]. Perhaps the use of an electronic sensor could be fitted at the base of the thumb to monitor the forces across the thumb CMC joint during the actual use of the thumb.…”

“…Although there is ample evidence to support the association of weakness of grip and pinch strength with advanced thumb CMC OA [8][9][10], the challenge is detecting the subtle changes of grip and pinch in early thumb CMC OA [5,6]. Coughlan and colleagues concluded that reduction in cylindrical grasp was associated with early thumb CMC OA, whereas gross grasp was not.…”