Funding agencies: The study was supported by the Medical Research Council of the UK, grant MR/J004685/1 to Professor Bronstein.
Protective stepping response in Parkinsonian patients and the effect of vibrotactile feedback
Version of Record online: 31 OCT 2012
Copyright © 2012 Movement Disorders Society
Volume 28, Issue 4, pages 482–489, April 2013
How to Cite
Lee, P.-Y., Gadareh, K., Naushahi, M. J., Gresty, M. and Bronstein, A. M. (2013), Protective stepping response in Parkinsonian patients and the effect of vibrotactile feedback. Mov. Disord., 28: 482–489. doi: 10.1002/mds.25227
Relevant conflicts of interest/financial disclosures: Nothing to report.
Full financial disclosures and author roles may be found in the online version of this article.
- Issue online: 8 APR 2013
- Version of Record online: 31 OCT 2012
- Manuscript Accepted: 6 SEP 2012
- Manuscript Revised: 31 JUL 2012
- Manuscript Received: 27 MAR 2012
- stepping response;
- Parkinson's disease;
- motor control;
The objectives of this study were (1) to characterize protective stepping responses to unpredictable forward/backward postural perturbation in Parkinson's disease (PD) and (2) to assess whether vibrotactile cues of the impending fall improve the stepping response. Twenty mild PD patients, 7 advanced PD patients, and 17 age-matched controls stood on a platform moving unpredictably forward and backward, requiring a protective step to maintain balance. Direction-coded vibrotactile cues, triggered by leg tilt, were provided to prompt step generation. All subjects showed quicker reaction time, shorter steps, and smaller total trunk displacement when stepping backward than when stepping forward. Advanced PD patients took shorter, slower, and an increased number of protective steps. The only abnormality observed in mild PD patients was slightly slower backward steps. Vibrotactile feedback reduced the amount of trunk displacement observed before taking a protective step but did not improve any abnormality in PD patients. Early PD patients had near-normal protective stepping responses to unpredictable perturbations, but advanced patients made slow and short steps both forward and backward. Given that latencies were preserved even in unpredictable conditions, step slowness and hypometria are the primary abnormalities of the stepping response in PD. As voluntary locomotor stepping in PD is reported to improve with sensory feedback, the lack of such improvement in our study implies that additional sensory cues cannot help automatic reflex-like stepping reactions in PD patients. © 2012 Movement Disorder Society