Identification of axial rigidity during locomotion in Parkinson disease

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 tr acking 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 sho wed significantly smaller changes in mean relative phase (p <.0001) and low er variability in relative phase (p <.0001) in the PD group. No significant differences were found in stride duration and variability in stride durati on. Conclusions: The relative phase data contradict traditional notions of incr eased variability in motor control in PD and pinpoint the importance of the trunk in identifying axial rigidity, This discrepancy may be due to lack o f control for walking velocity in earlier studies. It is concluded that sys tematic manipulation of walking velocity can identify coordination deficits and rigidity in trunk movement. This coordination of trunk movement can al so be a sensitive measure for (early) diagnosis and the assessment of movem ent and pharmacological therapy in PD. (C) 1999 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation.