Citation

Barton JE, Roy A, Sorkin JD, Rogers MW, Macko R. J. Biomech. Eng. 2015; ePub(ePub): ePub.

Copyright

(Copyright © 2015, American Society of Mechanical Engineers)

DOI

10.1115/1.4031486

PMID

26328608

Abstract

We developed a balance measurement tool (the Balanced Reach Test) to assess standing balance while reaching and pointing to a target moving in three-dimensional space according to a sum-of-sines function. We also developed a three-dimensional, 13-segment biomechanical model to analyze performance in this task. Using kinematic and ground reaction force data from the Balanced Reach Test we performed an in-verse dynamics analysis to compute the forces and torques applied at each of the joints during the course of a 90 second test. We also performed spectral analyses of each joint's force activations. We found that the joints act in a different but highly coordinated manner to accomplish the tracking task-with individual joints responding congruently to different portions of the target disk's frequency spectrum. The test and the model also identified clear differences between a young healthy subject, an older high fall risk subject be-fore participating in a balance training intervention; and in the older subject's performance after training (which improved to the point that his performance resembled that of the young subject). This is the first phase of an effort to model the balance control system with sufficient physiological detail and complexity to accurately simulate the multi-segmental control of balance during functional reach across the spectra of ag-ing, medical, and neurological conditions that affect performance. Such a model would provide insight into the function and interaction of the biomechanical and neurophysiological elements making up this system; and system adaptations to changes in these elements' performance and capabilities.

Language: en