The strength of the hand.

Although strength is one of the important characteristics of a normal hand, this factor is not given enough attention in reconstructive surgery as compared to other parameters of motion and sensibility. This paper presents the results of a study on strength in functional adaptations of the normal hand. A baseline of normal grip and pinch strength was obtained by testing a group of one hundred healthy persons. As it is necessary to know the normal to appreciate the abnormal, a parallel evaluation of the disabled hand could define the degree of impairment present (1,2,3,4,5). Regnier, 160 years ago, reported the first analysis of strength of the hand measured with a personally designed dynamometer (6). Some more recent studies were made by Lewey, Kuhn, and Juditski (1947), Bechtol (1954), and Mannerfelt (1966) (7,8,9). Isometric contractions of the hand muscles were measured with pneumatic (10) or hydraulic spring-scale dynamometers. The pinch meter used in our study is an electronic device designed by Kashiwagi's Orthopaedic Department at Kobe University, Kobe, Japan (1 1). The strength of the normal hand was recorded as applied in basic hand patterns: grip, chuck pinch (three-digit pinch), pulp (fingertip) pinch with separate fingers, and lateral pinch. Measurements are expressed in kilograms of force units.