Analysis of Stepping in Place Task in Parkinson’s Disease Using a Predictive Simulation Model

Parkinson's Disease (PD) severely impacts motor functions. This study uses a predictive simulation model to analyze the stepping in place (SIP) task, a method for assessing motor function and freezing of gait in patients with PD. We developed a musculoskeletal model with a neural controller to simulate SIP motion. The model demonstrated the effects of increased muscle tone and reduced muscle strength, conditions common in PD. Results show that increased muscle tone reduces knee angle range, while reduced muscle strength diminishes hip angle range and causes leg bending. This combination exacerbates motor rigidity and reduces stepping frequency. Our findings highlight muscle tone and strength's role in motor function and provide insights into PD motor impairments.