Asymmetrical arm swing possible early indicator of Parkinson's.
Article Type: Clinical report
Subject: Parkinson's disease (Development and progression)
Parkinson's disease (Diagnosis)
Parkinson's disease (Research)
Gait (Analysis)
Arm (Physiological aspects)
Arm (Research)
Extremities, Upper (Physiological aspects)
Extremities, Upper (Research)
Author: Hunter, Kim
Pub Date: 03/22/2010
Publication: Name: Australian Journal of Medical Herbalism Publisher: National Herbalists Association of Australia Audience: Academic Format: Magazine/Journal Subject: Health Copyright: COPYRIGHT 2010 National Herbalists Association of Australia ISSN: 1033-8330
Issue: Date: Spring, 2010 Source Volume: 22 Source Issue: 1
Topic: Event Code: 310 Science & research
Accession Number: 223823998
Full Text: Lewek MD, Poole R, Johnson J, Halawa O, Huang X. 2010. Arm swing magnitude and asymmetry during gait in the early stages of Parkinson's disease. Gait Posture 31:2;256-60.

Symptoms of Parkinson's disease (PD) include tremors at rest and stiffness in the body and limbs. According to the authors of this study by the time we diagnose the disease, about 50-80% of the critical cells (dopamine neurons) are already dead. Huang and colleagues thought that because PD is an asymmetrical disease, the arm swing on one arm will be lost first compared with the other. They suggested that irregular arm swings while walking could be an early sign of PD, and that scientific measurement of this could help diagnose the disease earlier, giving greater opportunity to slow brain cell damage and disease progression.

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 performed a quantitative analysis of arm swing magnitude and asymmetry that might be useful in the assessment of early PD. Twelve individuals with early PD and eight controls underwent gait analysis using an optically based motion capture system. The PD patients were in 'off' state, meaning they stayed off their medication overnight to stop it affecting the test results. Participants were instructed to walk at normal and fast velocities, and then on heels (to minimise push off). Arm swing was measured and arm swing magnitude for each arm and inter arm asymmetry, were compared between groups.

Both groups had comparable gait velocities 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 or less. But the PD group showed significantly greater arm swing asymmetry (asymmetry angle 13.9% [+ or -] 7.9%) compared with the control group (asymmetry angle 5.1% [+ or -] 4.0%; p = 0.003) and when the participants walked faster, the arm swing increased but the amount of asymmetry stayed the same.

The authors concluded that 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 be useful for early and differential diagnosis and for tracking disease progression in patients with later PD.

Kim Hunter MNHAA
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