Implications of an adjustable bed height during standard nursing tasks on spinal motion, perceived exertion and muscular activity

Manual handling is a source of occupational stress, particularly for nursin g personnel. High levels of biomechanical strain are associated with liftin g and transferring patients, especially when the tasks are performed in fle xed and twisted positions that induce an increased risk of functional and m usculoskeletal problems. The use of adjustable beds in nursing practice has been suggested as a means of influencing working postures and reducing the muscular demands on nurses. The purpose of this study was to investigate t he effects on spinal motion, muscular activity and perceived exertion when nurses had the opportunity to adjust bed height. The measures recorded duri ng the conduct of standardized patient handling tasks were the changes in p osture (inclination) and in shape (sagittal bending, side bending, axial ro tation). Muscular activity was measured using surface electromyography. Per ceived exertion was rated using the 15-graded Borg scale. The range of moti on was not influenced by the adjustment of bed height, but rather a shift o f the time duration histogram was noticed in the direction of the erect, sa fer position. The time spent in the safe zone of spinal motion near the ere ct position was significantly increased and was significantly decreased in the potential health-hazardous zones of spinal motion in the extreme positi ons. No differences in muscular activity or in perceived exertion were foun d between the two bed height conditions for any of the muscle groups. It wa s concluded that the quality of spinal motion is enhanced when the opportun ity of adjusting the bed height is offered.