Compressive and Shear Forces of L5/S1 during Patient Transfer in Different Loads on Hands

Abstract

Patient transfer is the primary cause of lower back pain among caregivers because it requires awkward postures and movements such as twisting, lifting, and lowering with heavy external loads such as body weight. To prevent lower back pain, the relationship between lumbar loads and external loads from patient weight should be investigated to explore the hazardous limits of external loads during patient transfer. However, this investigation requires frequent trials and heavier loads than the hazardous limit. Therefore, we have used a computational musculoskeletal simulation for patient handling without the actual measured load data of human subjects. A previous study used a musculoskeletal simulation of sit-to-stand assistance motion; however, this simulation did not consider twisting and lowering patient transfer. Hence, this study aims to investigate the relationship between lumbar loads and external loads during patient transfer, including twisting and lowering. The musculoskeletal simulation for this investigation was implemented using the 3D Static Strength Prediction Program. First, the implemented musculoskeletal simulation was validated by comparison with related research using actual measured motion data and an optical motion capture system. Furthermore, the relationship between lumbar loads (compressive and shear forces of L5/S1) and external loads during patient transfer was investigated using a validated musculoskeletal simulation. According to the results, the compressive and shear forces of L5/S1 during patient transfer exceeded the limits of safety when the external load was more than 40 kgf. These findings will contribute to the prevention of lower back pain due to patient transfer.

Foot Position Recognition Using a Smartphone Inertial Sensor in Patient Transfer

“…Caregivers experience lower back pain owing to lumbar loads during patient transfer. Patient transfer causes lumbar loads due to lowering, twisting, and lifting [1][2][3][4][5][6]. Thus, several assistive devices have been developed to avoid musculoskeletal loads during patient transfer [7].…”

“…However, this method cannot be applied to patient transfer, including twisting and lowering [22,23]. The posture during twisting and lowering should be measured and monitored because twisting and lowering cause lumbar loads on caregivers [5,24]. In addition, our previous method required the preparation of additional devices because this method requires shoe-type force sensors, which are not common devices [22,23].…”