GROUND REACTION FORCES DURING MINER CABLE PULLING TASKS

摘要

The handling of mining machine cables in underground coal mines has been identified as a particularly stressful task and is a likely contributor to low back pain. In this experiment, seven experienced miners performed a cable pulling task while ground reaction forces and cable tension were measured. The independent variables were two levels of cable resistance (low and high) and lifting conditions (kneeling under a 1.2 meter [48 inch] roof, stooping under a 1.2 meter [48 inch] roof, stooping under a 1.5 meter [60 inch] roof, and unrestricted standing). The dependent variables were the peak values of the following: actual tension measured in the cable, ground reaction forces in the X (anterior), Y (lateral), and Z (vertical) directions and the magnitude of the resultant force vector. Work posture significantly affected the peak ground reaction forces in the Y-direction. The Y-forces were highest in the kneeling condition, indicating that there is less postural stability when performing cable pulling tasks in a kneeling posture. Thus, there may be a greater likelihood of injury in this posture. Additionally, biomechanical stresses which contribute to musculoskeletal injury may be greater in the kneeling posture.