Perioperative Gait Analysis of Patients With Cervical Spondylotic Myelopathy Using Inertial Sensors

Cervical spondylotic myelopathy (CSM) is a progressive spinal disorder often associated with subtle yet clinically relevant gait impairments. Accurate gait evaluation during the perioperative period remains challenging due to the limitations of coarse clinical rating scales. This study employs a wearable gait analysis framework using foot-mounted inertial measurement units (IMUs) to extract spatiotemporal gait parameters with high precision, validated in an optical lab with relative errors of 2.4% for stride length (SL) and 5.5% for maximum foot clearance (MFC). A dataset of healthy controls and CSM patients was collected, and bilateral gait features were analyzed across pre- and postoperative stages. To enhance evaluation sensitivity, we introduce a Robust Gait Normalcy Index (RINI) based on the extracted gait features and robust principal component analysis (RPCA). RINI demonstrated a greater mean change in the Nurick improvement group with 1.72 and a stable change in the unchanged group with 0.36, outperforming other indices. These results suggest that RINI enables fine-grained and robust gait evaluation for CSM patients in the perioperative period.