Kinetic Interjoint Coordination in Lower Limbs during Gait in Patients with Hemiparesis

Abstract

The coordination of joint moments in the same limb—otherwise known as kinetic interjoint coordination—during gait in patients with hemiparesis remains unclear. This study clarifies the characteristics of kinetic interjoint coordination in the lower limbs using a principal component analysis (PCA). Using a three-dimensional motion analysis system and force plates, the kinematic and kinetic data from 29 patients with hemiparesis and 12 healthy controls were measured when they walked along a 7 m walkway. The spatiotemporal principal components (PCs) of the hip, knee, and ankle joint moments were calculated using a PCA and the motor modules during gait were identified. We adopted a case–control study design to clarify the kinetic interjoint coordination characteristics during gait in patients with hemiplegia. As the results of comparisons between the patients and controls showed, the peak timing of the first PC, which had high loadings of hip and ankle joint moments on the paretic side, was significantly earlier than that on the other sides. The loading of the knee joint moment for the first PC on the paretic side was significantly lower than that on the non-paretic side (p < 0.05), which was highly variable with negative and positive values. The results demonstrated that the first motor module comprising hip and ankle joint moments on the paretic side during gait in patients with hemiparesis may be merged with knee joint flexion or the extension moment, and may have an atypical temporal component. The index of kinetic interjoint coordination would be a useful tool for robotic-based systems for effective rehabilitation, which would significantly contribute to the acceleration of collaborative research in the fields of engineering and rehabilitation medicine.