Miners often handle heavy electrical power cables, which may weigh as much as 100 N per meter. Such cables are often manually lifted and hung to prevent them from being damaged by mobile underground equipment. Analysis of injury statistics indicate that workers who perform such a task experience an inordinate number of lost-time back injuries. Six male underground miners performed a series of 12 cable hanging tasks in standing, stooping, and kneeling postures under various vertical space constraints (from 1.2 to 2.1 m). Two methods of hanging the cable were evaluated (hanging on a hook or tying with a wire). Kinematic data and ground reaction forces were collected, as were electomyograms (EMG) of ten trunk muscles. Results indicate that reduced vertical space increased the moment about the lumbar spine no matter which posture was used (p<0.05). Hanging the cable was accomplished more quickly with a hook than when tying with a wire. Analysis of EMG data indicate higher activity levels when using the wire to affix the cable as opposed to hanging it on a hook (p<0.05). Results of this study will be used to recommend safe work practices for handling cables in underground coal mines.
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