Isolated finger flexion force--a methodological study.

A method is presented for measuring isolated finger flexion force in a transverse volar grip in a standardized manner. Normal values for forty healthy subjects are given. The mean force of the digits varied from 5.9 to 10.6kp, the middle finger being the strongest, followed by the index, ring and little finger. Large individual variations were observed, especially among men. Men were significantly stronger than woman in corresponding digits. The symmetry between the hands, judged by the order of strength of the fingers, was good in both sexes but especially in women. It is suggested that the strength ratio between dominant and non-dominant might be used to assess the recovery of finger flexion force after, for instance, tendon surgery. Although a correlation exists between isolated finger flexion force and vigorimetric values of the hand grip strength, it is of little value in evaluation of an individual patient.