Relationship between Foot Position and Lumbar Loads while Turning Patients on a Bed: An Investigation via Computational Simulation and Electromyography

Caregivers have lower back pain (LBP) since they must reposition patients in bed frequently. Thus, the low lumbar load posture for turning patients should be explored. In this study, we focused on foot position because it can be easily adjusted to reduce back pain. The hypothesis was that short anteroposterior foot distance could reduce lumbar loads because closer position to patient made smaller moments. Therefore, this study aimed to investigate the relationship between foot position and lumbar loads while turning patients on beds. Furthermore, we compared compression stresses of L4–L5 via computational simulation and erector spinae muscle activities obtained from electromyography (EMG) in nine foot positions. The results showed that short anteroposterior foot distance reduced lumbar loads while turning a patient on a bed.