Reliability, validity, and responsiveness of pinch strength assessment: a systematic review

PURPOSE: To summarize and critically appraise the quality of studies investigating psychometric properties of pinch strength assessment. METHODS: Medical literature up to February 2024 was searched for studies reporting on at least one measurement property of pinch strength assessment. The quality of the evidence and the risk of bias were rated using COSMIN 2018 guidelines. RESULTS: Thirty-three studies (1962 participants) were included. The majority (16/19) of reliability studies were of adequate to very good quality. Seven of 12 studies of validity were rated as adequate or very good. The quality of the eight responsiveness studies was adequate. Reliability was good to excellent (ICC > 0.75) for neurological conditions, and excellent (ICC > 0.90) for musculoskeletal disorders and healthy participants. Pinch strength showed strong to very strong correlations with grip strength (r = 0.72-0.92), moderate to strong correlations with assessments of dexterity (r = 0.78-0.80), and weak to moderate correlation with patient-reported outcome measures (r = 0.03-0.50). Varied results were found for pinch strength responsiveness in a small number of studies. CONCLUSIONS: Pinch strength assessment is reliable. Validity and responsiveness are less reported, but there is a strong correlation between pinch and grip strength, and a moderate correlation with dexterity.