Effects of different vibration frequencies on muscle strength, bone turnover and walking endurance in chronic stroke

Author: Zhenhui Yang1,2, Tiev Miller1, Zou Xiang3, Marco Y C Pang4
Affiliation: <sup>1</sup> Department of Rehabilitation Sciences, Hong Kong Polytechnic University, 11 Yuk Choi Road, Hung Hom, Hong Kong. <sup>2</sup> Department of Physical Therapy, Guangdong Provincial Work Injury Rehabilitation Hospital, Guangzhou, China. <sup>3</sup> Department of Health Technology and Informatics, Hong Kong Polytechnic University, Hung Hom, Hong Kong. <sup>4</sup> Department of Rehabilitation Sciences, Hong Kong Polytechnic University, 11 Yuk Choi Road, Hung Hom, Hong Kong. marco.pang@polyu.edu.hk.
Conference/Journal: Sci Rep
Date published: 2021 Jan 8
Other: Volume ID: 11 , Issue ID: 1 , Pages: 121 , Special Notes: doi: 10.1038/s41598-020-80526-4. , Word Count: 178


This randomized controlled trial aimed to evaluate the effects of different whole body vibration (WBV) frequencies on concentric and eccentric leg muscle strength, bone turnover and walking endurance after stroke. The study involved eighty-four individuals with chronic stroke (mean age = 59.7 years, SD = 6.5) with mild to moderate motor impairment (Fugl-Meyer Assessment lower limb motor score: mean = 24.0, SD = 3.5) randomly assigned to either a 20 Hz or 30 Hz WBV intervention program. Both programs involved 3 training sessions per week for 8 weeks. Isokinetic knee concentric and eccentric extension strength, serum level of cross-linked N-telopeptides of type I collagen (NTx), and walking endurance (6-min walk test; 6MWT) were assessed at baseline and post-intervention. An intention-to-treat analysis revealed a significant time effect for all muscle strength outcomes and NTx, but not for 6MWT. The time-by-group interaction was only significant for the paretic eccentric knee extensor work, with a medium effect size (0.44; 95% CI: 0.01, 0.87). Both WBV protocols were effective in improving leg muscle strength and reducing bone resorption. Comparatively greater improvement in paretic eccentric leg strength was observed for the 30 Hz protocol.


PMID: 33420277 DOI: 10.1038/s41598-020-80526-4