Biomechanical Analysis of Load Lifting Techniques: An Evaluation of Squat and Stoop Methods on Lumbar and Knee Joint moments and Forces

Biomechanical analysis of manual load lifting techniques is crucial for understanding their impact on joint health, particularly in the lumbar spine and knee joints, which are prone to injury during manual material handling tasks. This study examines the effects of three common lifting postures squat, semi-stoop, and stoop on joint forces and moments at the lumbar spine (L۵/S۱) and knee joints using motion capture technology and biomechanical modeling. The results revealed significant differences in shear (FX) and compression (Fz) forces at the lumbar spine with varying knee flexion angles (۱۰°, ۳۵°, and ۷۰°) in a Lordotic position. Additionally, significant variations in internal joint moments, particularly sagittal moments (Lumbar-Mx and Knee-Mx), were observed across different knee flexion angles. These findings emphasize the importance of maintaining proper lifting techniques and posture to minimize musculoskeletal injury risk, particularly in the lower back and knees. In conclusion, the study underscores the importance of adopting proper lifting techniques, particularly those that encourage deep knee flexion and a neutral spine position, to minimize musculoskeletal injury risks. It is recommended that future ergonomic practices and training programs prioritize these postures to optimize safety. Further research is needed to explore how variations in posture, load, and lifting techniques can optimize lifting safety and efficiency.

کلیدواژه ها:

Biomechanics ، Knee flexion ، Lumbar spine ، Manual lifting ، Joint moments