Identification of axial rigidity during locomotion in parkinson disease

Abstract

Objectives: To identify coordination changes and stability in the movements of the trunk during locomotion in Parkinson disease (PD) as a function of walking velocity. Study Design: Comparison of treadmill locomotion with an opto-electronic tracking device. Patients: Newly diagnosed patients with PD ( n = 27) and a group of healthy control subjects ( n = 11). Results: Coordination between transversal pelvic and thoracic rotations showed significantly smaller changes in mean relative phase ( p < .0001) and lower variability in relative phase ( p < .0001) in the PD group. No significant differences were found in stride duration and variability in stride duration. Conclusions: The relative phase data contradict traditional notions of increased variability in motor control in PD and pinpoint the importance of the trunk in identifying axial rigidity. This discrepancy may be due to lack of control for walking velocity in earlier studies. It is concluded that systematic manipulation of walking velocity can identify coordination deficits and rigidity in trunk movement. This coordination of trunk movement can also be a sensitive measure for (early) diagnosis and the assessment of movement and pharmacological therapy in PD.