Optimal bed height for passive manual tasks

Purpose: To determine bed height adjustment for maintaining neutral lumbar position as a function of anthropometric dimensions. Materials and methods: 80 physical therapy students performed passive shoulder flexion and straight leg raising tasks on standard versus the adjustable bed. The lumbar angle was measured at the start and finish of tasks. The rate of perceived exertion was measured immediately after each task. The most comfortable bed height in relation to some anatomical landmarks was measured. Results: Mean bed height for shoulder flexion tasks was significantly higher than for straight leg raising. The mean adjusted bed heights for both tasks were significantly higher and with less exertion felt by the participants, compared to the standard bed height (0.715 m). The third knuckle of the hand and the radial styloid process of the wrist were established as the most valuable anthropometric landmarks for bed height adjustment. Conclusions: The above landmarks are recommended to maintain a neutral lumbar position while adjusting bed heights for manual tasks. Each manual task requires adjustment of the bed height. Further studies are needed to confirm our results.