Omnidirectional assessment of one-handed manual strength at three handle heights.

Abstract

Maximal right-handed omnidirectional strengths of eleven males were measured at three handle heights of 1.5 m, 1.0 m and 0.5 m using the Tri-Axial Force measurement System. The postures of the subjects were constrained by preventing rotation of the footbase in order to ensure that the forward-backward and leftward-rightward axes of the subject remained constant relative to the measurement system. A two-way repeated measures analysis of variance revealed highly significant differences in maximal strengths between the three heights and the 614 directions of exertion measured. A highly significant interaction was found between height and direction. At all three hand heights a restricted area of great strength was found in the direction of upward and almost directly forward from the subject. A second, less powerful, but more widespread area of high strength was also found at each height. At the 1.5-m height the peak was in the backward and almost vertically downward area. At the 1.0-m height the peak was in the area of slightly downward and largely backward. At the 0.5-m height the peak was to the right of upward and backward. RELEVANCE: Very few real-life manual exertions involve forces which are purely in the sagittal, forward-backward plane, with lateral components of force usually being involved as well. The data presented extend the knowledge base about male one-handed strengths.