Author: Liao LR1, Ng GY2, Jones AY3, Chung RC4, Pang MY5.
1L.R. Liao, MPT, Department of Physiotherapy, Guangdong Provincial Work Injury Rehabilitation Hospital, Guangzhou, China, and Department of Rehabilitation Sciences, Hong Kong Polytechnic University, Hong Kong, China. 2G.Y.F. Ng, PhD, Department of Rehabilitation Sciences, Hong Kong Polytechnic University. 3A.Y.M. Jones, PhD, School of Allied Health Sciences, Griffith University, Gold Coast, Australia. 4R.C.K. Chung, PhD, Department of Rehabilitation Sciences, Hong Kong Polytechnic University. 5M.Y.C. Pang, PhD, Department of Rehabilitation Sciences, Hong Kong Polytechnic University, Hong Kong, China.
Conference/Journal: Phys Ther.
Date published: 2015 May 28
Other: Word Count: 274
Whole-body vibration (WBV) has increasingly been used as an adjunct treatment in neurological rehabilitation. However, how muscle activation level changes during exposure to different WBV protocols in individuals after stroke remains understudied.
To examine the influence of WBV intensity on the magnitude of biceps femoris (BF) and tibialis anterior (TA) muscle activity and its interaction with exercise and severity of motor impairment and spasticity among individuals with chronic stroke.
Each of the 36 individuals with chronic stroke (mean age±standard deviation=57.3 ±10.7 years) performed eight different static exercises under three WBV conditions: (1) no WBV, (2) low-intensity WBV [20Hz, 0.60mm, peak acceleration: 0.96 units of gravity of Earth (g)], and (3) high-intensity WBV (30Hz, 0.44mm, 1.61g). The levels of bilateral TA and BF muscle activity were recorded using surface electromyography (EMG).
The main effect of intensity was significant. Exposure to the low-intensity and high-intensity protocols led to a significantly greater increase in normalized BF and TA EMG magnitude in both legs compared with no WBV. The intensity × exercise interaction was also significant, suggesting that the WBV-induced increase in EMG activity was exercise-dependent. The EMG responses to WBV were similar between the paretic and non-paretic legs, and were not associated with level of lower extremity motor impairment and spasticity.
Leg muscle activity was measured during static exercises only.
Adding WBV during exercise significantly increased EMG activity in TA and BF. The EMG responses to WBV in the paretic and non-paretic legs were similar, and were not related to degree of motor impairment and spasticity. The findings are useful for guiding the design of WBV training protocols for people with stroke.
© 2015 American Physical Therapy Association.