Biomechanical analysis and optimization of barbell exercises

Incorrect barbell deadlift and squat movements increase the pressure on the lumbar intervertebral discs, thereby posing a risk of injury. This study innovatively developed a three-dimensional biomechanical model of the human body with joints such as the ankle, knee, and hip as nodes, significantly surpassing traditional two-dimensional lifting models. This three-dimensional model more comprehensively simulates the dynamic mechanical behavior in barbell exercises, allowing for accurate calculations of joint pressures and shear forces in complex movement postures. The model calculated the pressure and shear forces on the L5/S1 joint under different movement postures and explored the effects of different stance angles and maximum ankle flexion angles on the peak pressure at the L5/S1 joint. The results indicated that increasing the maximum flexion angle of the ankle significantly reduces the peak pressure on the lumbar spine, while adjusting the stance angle had a negligible effect on reducing peak pressures. Additionally, this study conducted simulations for a specific individual (Olympic weightlifting champion SHI ZhiYong), verifying the personalized applicability of the model. This research not only provides a scientific basis for understanding and optimizing barbell movements but also offers digital guidance for designing safe and effective training plans.