Gait measurement and quantitative analysis in patients with Parkinson's disease for rehabilitation assessment

Patients with Parkinson's disease have symptom of walking disorders which can be alleviated by surgery. By evaluating gait kinematics, the effect of medical treatment can be quantitatively assessed. In this paper, a method using image markers based on rigid body was introduced to set markers on anatomy key points of human lower limbs, which efficiently reduced the measurement errors coming from the skin movement during motions. Eleven Parkinson's disease (PD) patients with subthalamic nucleus deep brain stimulation (STN-DBS) implantation and five non-diseased subjects participated in gait measurement experiments. They were divided into groups of three different status: DBS ON, DBS OFF and Controls, and the subjects' gaits were recorded by a motion capture instruments. By calculating the three-dimensional coordinates of image markers in several gait cycles, we obtained gait kinematics and spatiotemporal parameters, such as joints angles, stride interval, cadence, stride length, and stride velocity. The gait parameters of DBS ON, DBS OFF and Controls were compared in pairs by the One-way Analysis of Variance. We found that the joint angle rotation range, stride length and stride velocity of each group all show a significant difference between the diseased and non-diseased (p<;0.01), and that with patients' relief of symptoms, the value discrepancies of these parameters became more obvious (DBS OFF <; DBS ON <; Controls). Analysis based on experiments shows that the method proposed here is an effective way to measure gait parameters, which can be used in patients with Parkinson's disease for quantitative rehabilitation assessment.