Exploring inter-joint coordination with and without dopaminergic medication in Parkinson's Disease

Abstract-Text (inkl. Referenzen und Bildunterschriften)

People with Parkinson's disease (PD) often have impaired gait function, leading to disturbed walking, instable posture and falls. One reason is that PD affects the inter-joint coordination. This study proposes a quantitative approach to the comparative representation of the hip and knee joint movement during straight walking in PD patients and controls. The hip-knee coordination is represented by cyclograms (angle-angle plots) for 29 PD subjects on medication (additionally 8 of them off medication) and 29 controls under slow, preferred and fast walking conditions. Data were collected using an optical motion capture system. Significant differences were found between the PD on medication and control groups, as well as within the groups (between walking speeds) in hip and knee range-of-motion, where PD group displayed lower values. Furthermore, cycle-to-cycle consistency and cyclogram shapes were larger in controls than in PD on medication group, and even larger than in PD medication off group. Compared to both PD groups, controls displayed the biggest variation between walking speeds. These results suggest an impaired adaptation of inter-joint coordination with changing walking speed. The methods used here can be extended to analysing other joint combinations and using cohorts from other mobility limiting diseases. Moreover, these methods could be used to develop and validate the parameters that could eventually be used as intermediate clinical endpoints aiding in disease diagnosis as well as in assessing the response to treatment.

Figure 1. Average cyclograms of controls (plot a), PD medication on (plot b), PD medication on (those measured both on and off medication, n = 8) (plot c) and PD medication off (n = 8) (plot d) from fast (solid line), preferred (dashed line) and slow (dotted line) walking speed trials. Black cross (0,0) indicates cyclogram centroids. The circles and stars indicate minimum and maximum cyclogram points, respectively.