The later stages of Parkinson's disease (PD) are characterized by altered gait patterns. Although decreased arm swing during gait is the most frequently reported motor dysfunction in individuals with PD, quantitative descriptions of gait in early PD have largely ignored upper extremity movements. This study was designed to perform a quantitative analysis of arm swing magnitude and asymmetry that might be useful in the assessment of early PD. Twelve individuals with early PD (in "off" state) and eight controls underwent gait analysis using an optically-based motion capture system. Participants were instructed to walk at normal and fast velocities, and then on heels (to minimize push-off). Arm swing was measured as the excursion of the wrist with respect to the pelvis. Arm swing magnitude for each arm, and inter-arm asymmetry, were compared between groups. Both groups had comparable gait velocities (p=0.61), and there was no significant difference between the groups in the magnitude of arm swing in all walking conditions for the arm that swung more (p=0.907) or less (p=0.080). Strikingly, the PD group showed significantly greater arm swing asymmetry (asymmetry angle: 13.9±7.9%) compared to the control group (asymmetry angle: 5.1±4.0%; p=0.003). Unlike arm swing magnitude, arm swing asymmetry unequivocally differs between people with early PD and controls. Such quantitative evaluation of arm swing, especially its asymmetry, may have utility for early and differential diagnosis, and for tracking disease progression in patients with later PD.
KeywordsParkinson's Disease; gait; biomechanics; arm swing; arm swing asymmetry © 2009 Elsevier B.V. All rights reserved.Corresponding Author: Xuemei Huang MD, PhD Penn State University-Milton S. Hershey Medical Center, H037 Department of Neurology, 500 University Drive Hershey, PA 17033-0850 Phone: 717-531-1803 Fax: 717-531-0465 xuemei@psu.edu. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Conflict of interest statement:The authors have nothing to disclose related to any financial and personal relationships with other people or organizations that could inappropriately influence (bias) our work.
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NIH-PA Author ManuscriptParkinson's disease (PD) is the second most common age-related, neurodegenerative disorder. Tremor, rigidity, bradykinesia, and postural instability are hallmarks for the diagnosis of PD. 1 Abnormal gait (i.e., small "shuffling" steps) is common in the later stages of PD, and can be characterized by reduced walking velocity, stride length, swing/s...