Comparison of grip strength among 6 grip methods.

Purpose: To measure grip strengths using several methods by serially excluding 1 or 2 phalanges using a flexion-block orthosis and comparing those with standard grip posture in order to facilitate prediction of clinical or functional outcomes that relate to the contribution of each finger to grip strength.

Methods: Two hundred healthy men aged 25 to 30 years were included in the survey. Demographic variables were collected, and anthropometric measurements of the forearm and hand were obtained. Grip strength was measured using all fingers, all fingers except the thumb, all fingers except the index finger, all fingers except the middle finger, all fingers except the ring and little fingers, and all fingers except the little finger. The contribution of each finger to the total grip strength was estimated using the weight value concept.

Results: Grip strength using all 5 fingers was greatest, and the grip strength without the thumb was the second greatest. Grip strengths without the middle finger and without the ring and little fingers were the lowest. Various degrees of positive correlations between each grip method and 8 anthropometric parameters were found. Contributions of the thumb, index, middle, and ring and little fingers to the grip strength were 17%, 22%, 31%, and 29%, respectively.

Conclusions: The middle finger was the most important contributor to grip strength. The next most important was the combination of the ring and little fingers.

Clinical Relevance: The present estimated contributions of each finger to grip strength may facilitate prediction of the clinical or functional outcomes of various pathological conditions.