Affiliations: [a] Department of Biomedical Engineering, Cleveland Clinic, Cleveland, OH, USA
| [b]
Center for Neurological Restoration, Cleveland Clinic, Cleveland, OH, USA
| [c]
Cleveland Clinic Concussion Center, Cleveland Clinic, Cleveland, OH, USA
| [d] Qualitative Health Services, Cleveland Clinic, Cleveland, OH, USA
Correspondence:
[*]
Address for correspondence: Jay L. Alberts, Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA. Tel.: +1 216 445 3222; Fax: +1 216 444 9198; E-mail: albertj@ccf.org.
Abstract: BACKGROUND: Postural instability is a hallmark of Parkinson’s disease. Objective metrics to characterize postural stability are necessary for the development of treatment algorithms to aid in the clinical setting. OBJECTIVE: The aim of this project was to validate a mobile device platform and resultant three-dimensional balance metric that characterizes postural stability. METHODS: A mobile Application was developed, in which biomechanical data from inertial sensors within a mobile device were processed to characterize movement of center of mass in the medial-lateral, anterior-posterior and trunk rotation directions. Twenty-seven individuals with Parkinson’s disease and 27 age-matched controls completed various balance tasks. A postural stability metric quantifying the amplitude (peak-to-peak) of sway acceleration in each movement direction was compared between groups. The peak-to-peak value in each direction for each individual with Parkinson’s disease across all trials was expressed as a normalized value of the control data to identify individuals with severe postural instability, termed Cleveland Clinic-Postural Stability Index. RESULTS: In all conditions, the balance metric for peak-to-peak was significantly greater in Parkinson’s disease compared to controls (p < 0.01 for all tests). CONCLUSIONS: The balance metric, in conjunction with mobile device sensors, provides a rapid and systematic metric for quantifying postural stability in Parkinson’s disease.
Keywords: Parkinson’s disease, postural stability, mobile device, biomechanics
