Biomechanical Analysis of Peak and Cumulative Spinal Loads During Simulated Patient-handling Activities: a Substudy of a Randomized Controlled Trial to Prevent Lift and Transfer Injury of Health Care Workers

Back injuries are a serious problem for nursing personnel who perform frequent patient-handling activities. Common prevention strategies include body mechanics education, technique training, and ergonomic interventions such as the introduction of assistive equipment. This investigation assessed and compared the effectiveness of two patient-handling approaches to reducing injury risk. One strategy involved using improved patient-handling technique with existing equipment, and the other approach aimed at eliminating manual patient handling through the use of additional mechanical and other assistive equipment. Both intervention arms received training in back care, patient assessment, and use of the equipment available on their particular wards. An analysis of compliance with interventions and the effects of patient-handling methods on both peak and cumulative spinal compression and shear during various tasks was conducted. Results showed greater compliance with interventions that incorporated new assistive patient-handling equipment, as opposed to those consisting of education and technique training alone. In several tasks, subjects who were untrained or non-compliant with interventions experienced significantly higher peak spinal loading. However, patient-handling tasks conducted with the aid of assistive equipment took substantially longer than those performed manually. This, along with variations in techniques, led to increases in cumulative spinal loading with the use of patient-handling equipment on some tasks. Thus, the use of mechanical assistive devices may not always be the best approach to reducing back injuries in all situations. No single intervention can be recommended; instead all patient-handling tasks should be examined separately to determine which methods maximize reductions in both peak and cumulative lumbar forces during a manoeuver.