Musculoskeletal Model Construction of Deep Squat Using Low-Cost Inertial Measurement Units

Squatting is a compound exercise that can provide strong stimulation to the entire lower limb and trunk, positively affecting cardiovascular functions, neural regulations, and hormone secretion. In addition, squatting is commonly involved in labor intensive tasks where potential injuries may happen, and assistive devices are needed. In this study, we developed a low-cost IMU data acquisition system for capturing human squatting movements, with a total cost of only ~500 UGD. We conducted experiments on normal squats and knee valgus squats. The data obtained is imported into the OpenSim software for analysis, and we obtain experimental results on joint angles, joint moments, muscle forces, and metabolism. The results show that incorrect squatting postures can increase the burden on the hip joint. Additionally, during the squatting process, the tibialis anterior muscle had the highest activation level, while the soleus muscle had the greatest force. Our experimental and simulation results provide guidelines for future design and optimization of exoskeletons to assist humans during squat motions while reducing the risk of injuries.