Biomechanical evaluation of assistive devices for transferring residents

• Published in: Applied ergonomics 1999-08, Vol.30 (4), p.285-294
• Main Authors: Zhuang, Ziqing, Stobbe, Terrence J., Hsiao, Hongwei, Collins, James W., Hobbs, Gerald R.
• Format: Article
• Language: English
• Subjects: Applied physiology; Back injury; Biological and medical sciences; Biomechanical evaluation; Biomechanical Phenomena; Ergonomics; Ergonomics. Work place. Occupational physiology; Evaluation Studies as Topic; Female; Human physiology applied to population studies and life conditions. Human ecophysiology; Humans; Male; Medical equipment; Medical sciences; Movement; Nurses' Aides; Occupational hazards; Patient-handling devices; Patients; Self-Help Devices; Task Performance and Analysis; Transportation of Patients
• ISSN: 0003-6870; 1872-9126
• DOI: 10.1016/S0003-6870(98)00035-0

This is the first of two articles to report a biomechanical evaluation and psychophysical assessment of nine battery-powered lifts, a sliding board, a walking belt, and a baseline manual method for transferring nursing home residents from a bed to a chair. The objectives of the biomechanical evaluation were: (1) to investigate the effects of transfer method and resident weight on the biomechanical stress to nursing assistants performing the transferring task, and (2) to identify resident-transferring methods that could reduce the biomechanical stress to the nursing assistants. Nine nursing assistants served as test subjects; two elderly persons participated as residents. A four-camera motion analysis system, two force platforms, and a three-dimensional biomechanical model were used to measure biomechanical load. The results indicate that transfer method and resident weight affect a nursing assistant’s low-back loading. The basket-sling and overhead lift devices significantly reduced the nursing assistants’ back-compressive forces during the preparation phase of a resident transfer. In addition, the use of basket-sling, overhead, and stand-up lifts removed about two-thirds of the exposure to low-back stress (lifting activities per transfer) as compared to the baseline manual method. Thus, the use of these devices reduces biomechanical stress, and thereby will decrease the occurrence of resident-handling-related low-back injuries. Furthermore, lifting device maneuvering forces were found to be significantly different and a number of design/use problems were identified with various assistive devices. The second article will detail the psychophysical assessment of the same resident-transferring methods.