Study of lower limb inter-joint coordination during gait of the patients with early-stage osteonecrosis of the femoral head.

Abstract

Previous studies have confirmed that abnormal hip joint mechanics may significantly impact knee joint function. However, traditional gait analysis primarily focuses on the kinematic parameters of individual joints, which to some extent limits its ability to comprehensively reveal the inter-joint coordination patterns and their interaction relationships in the lower limb during gait in patients with hip pain. In this study, the vector coding (VC) method was employed to quantitatively analyze the inter-joint coordination patterns of the patients with early-stage osteonecrosis of the femoral head (ONFH). The sample consisted of 20 individuals, divided into 2 groups: control (CTRL, n = 10) and ONFH in the early stages (ONFH, n = 10). An infrared motion capture system was used to collect kinematic data of the hip, knee, and ankle joints during gait. Phase analysis of the stance phase was conducted based on coupling angle (CA) and coordination variability. Results showed that, relative to the CTRL group, the ONFH group exhibited a significantly smaller range of motion (ROM) of the hip joint (46.58%) and the knee joint (41.96%) in the sagittal plane at the middle third of stance, while the ROM of the ankle joint was larger (10.41%) throughout the whole stance phase. Furthermore, the analysis of coordination patterns between the hip-knee, knee-ankle, and hip-ankle joint pairs revealed a distinct distal compensation pattern in the ONFH group. During the middle third of stance, the hip-knee and hip-ankle coordination variability in the ONFH group was significantly higher than that in the CTRL group. This may suggest that the central nervous system (CNS) of patients is developing and refining new inter-joint coordination patterns that adapt to joint dysfunction in a more protective manner to alleviate pain. These findings provide insights into the unique patterns of the patient-specific inter-joint coordination and compensatory strategies of patients with early-stage ONFH, enhancing the understanding of their gait characteristics and providing crucial biomechanical evidence for designing personalized rehabilitation programs.