Occupational Ergonomics and Biomechanics Laboratory

OBJECTIVE:: The aim of this study was to evaluate the efficacy of commercially available friction-reducing patient-transfer devices in reducing biomechanical stresses on caregivers and patients.

BACKGROUND:: Caregivers suffer from high prevalence of work-related musculoskeletal disorders, which is associated with manual patient handling. However, there is not enough information available on the efficacy of various friction-reducing devices in reducing biomechanical stresses in the upper extremities and low back.

METHOD:: During patient-transfer tasks performed by 20 caregivers, we measured hand force; shoulder and trunk posture; shoulder moment; muscle activity in the flexor digitorum superficialis, extensor digitorum communis, biceps, triceps, trapezius, and erector spinae; and usability ratings from four devices: a draw sheet, a repositioning sheet, a slide board, and an air-assisted device. In addition, triaxial head acceleration of mock patients was measured to evaluate patients' head acceleration.

RESULTS:: The slide board and air-assisted device significantly reduced hand force ( p < .001), shoulder flexion ( p < .001), shoulder moment ( p < .001), muscle activities of caregivers ( p < .004), and patients' head acceleration ( p < .023) compared with the draw sheet. However, no significant differences in biomechanical measures were found between the repositioning and draw sheets. The air-assisted device consistently showed the lowest biomechanical stresses and was most preferred by participants.

CONCLUSION:: Reduction in caregivers' biomechanical stresses and mock patients' head acceleration indicates that a slide board and an air-assisted device can be effective engineering controls to reduce risk of injury.

APPLICATION:: The study results can provide a recommendation for engineering controls to reduce biomechanical stresses for both caregivers and patients.