Injuries associated with MMH continue to pose a significant problem to industry, both in terms of human suffering and economic losses. Three approaches to the control of such injuries have been employed: (1) ergonomic job design, (2) replacement screening, and (3) training and education. While ergonomic job design is effective, it has not alleviated injuries associated with MMH. Due to the effectiveness of training and education, replacement screening is the most promising method to augment ergonomic job design. The first specific aim of the proposed research is to empirically investigate the role that power, the dot product of force and velocity, may have in determining an individual's lifting capacity. Twenty five male subjects will participate in the experiment. Power will be assessed through both isokinetic and isoinertial techniques. It is hypothesized that power plays a greater role in lifting capacity that previously used measures, particularly isometric strength. The second specific aim of the proposed research is to elucidate the relative importance that strengths - measured by various techniques have in predicting lifting capacity. Isometric strength, power assessed rough isokinetic and isoinertial techniques, and isoinertial lifting capacity measured on the X-factor 6 ft, incremental lifting machine will be related to maximum lifting capacity through statistical methods. Thus, the secondary aim is more general than the first aim, but will provide a useful and informative comparison f several techniques used by previous researchers, as well as power which is proposed here. The proposed research can best be described as a pilot investigation that will provide valuable insight or future investigations which cover a broader set of task conditions and a larger subject pool. At this time, the relative contributions of various strengths to lifting capacity are unclear, and the proposed research will reduce this uncertainty. Once the most important determinants of lifting capacity are understood, a large- scale study can be designated which could result in the ability to predict lifting capacity with more precision ban current models provide. The proposed research will also provide insight into how dynamic capabilities, as opposed to static measures very popular in previous research, influence lifting capacity.
