Suchergebnisse

The supermarket industry has one of the highest numbers of repeated trauma illnesses. Checkout departments have a rate of musculoskeletal injuries 2 to 3 times higher than that of other supermarket departments. The primary objective of this study was to quantify the wrist motions required to bag groceries using a wrist motion monitor. The wrist motions included deviations, velocities, and accelerations for flexion-extension, radial-ulnar, and pronation-supination directions. The independent variables were handle type and object location. Objects with finger-thumb couplings required more extreme pronations, greater wrist velocities for pronation-supination deviations, and greater wrist accelerations for pronation-supination deviations than did other objects. Objects with 10-cm hand couplings required more extreme flexion, larger ranges of movement for radial-ulnar deviations and pronation-supination deviations, and greater wrist velocities in the radial-ulnar and pronation-supination directions than did 5-cm objects. The right and front locations required more extreme deviations than did the left and back locations. Because finger-thumb and 10-cm hand couplings require larger wrist deviations and greater velocities, these objects may pose a greater risk of developing cumulative trauma disorders to the bagger. Potential applications of this research include engineering design of grocery packaging and supermarket bagging workstations.

Available anthropometric information on the elderly in the United States is discussed. Demographic data as well as information on performance capabilities and limitations (such as strength, endurance, and mobility) are needed for ergonomic design of tools, utensils, equipment, and vehicles to improve the working and living environment for the elderly. Recommendations are made for collection of more information.

A model of the regulation of muscle strength exertion is proposed. Based on the model, methods are discussed to assess whether a subject exerts maximal or submaximal efforts. Results with 40 subjects indicate that a simple technique may be developed to judge if a subject is following instructions to exert a maximal contraction in a routine test of voluntary muscle strength.

The selection and use of distress signals is crucial for a boater in any emergency. This situation is intensified by the fact that boaters are usually not familiar with such devices. Therefore, incorporation of human factors/ergonomics variables into the design of distress signals can be an important element in boater survival. This report presents a systematic method to evaluate and confirm the effectiveness of human factors/ergonomics variables in the design of distress signals. The effects of several identified variables were tested individually in the lab and synergistically in a (simulated) on-water emergency. It was found that emergency signals that were designed according to human factors/ergonomics recommendations generally required less time to operate than devices that did not follow such guidelines.