Force, speed and power output of the human upper limb during horizontal pulls.

The purpose of the experiment was to examine how force, speed and power output of horizontal pulling with the upper limb was affected by the height of pull. Fourteen seated male subjects made horizontal pulls with maximal effort at eye, shoulder and elbow level from their positions of full reach when the trunk and shoulder girdle were rigidly constrained. Dynamic pulls were performed against a water-filled viscous dynamometer in which the resistance, proportional to the square of the velocity, could be varied. The height of pull had no significant effect on either static or dynamic performance. A force-velocity-position surface is presented which describes the conditions at the handle during the pulls. It confirms the importance of degree of reach upon the dynamic performance, and over a greater range of velocities than has been studied previously. A simple model shows that the similarity of performance at eye, shoulder and elbow heights is remarkable because they occur under very different biomechanical circumstances. The total work done in a complete pull increases with resistance. Peak power output is obtained against the same resistance (50 kg m-1) that was reported for elbow flexion and standing pulls.