Article

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.
The purpose of this study was 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 with severity
of motor impairment and spasticity among individuals with chronic stroke.
METHODS: Each of the 36 individuals with chronic stroke (mean age=57.3 years,
SD=10.7) performed 8 different static exercises under 3 WBV conditions: (1) no
WBV, (2) low-intensity WBV (frequency=20 Hz, amplitude=0.60 mm, peak
acceleration=0.96g), and (3) high-intensity WBV (30 Hz, 0.44 mm, 1.61g). The
levels of bilateral TA and BF muscle activity were recorded using surface
electromyography (EMG). RESULTS: 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 muscle electromyographic magnitude in
both legs compared with no WBV. The intensity x exercise interaction also was
significant, suggesting that the WBV-induced increase in EMG activity was
exercise dependent. The EMG responses to WBV were similar between the paretic and
nonparetic legs and were not associated with level of lower extremity motor
impairment and spasticity. LIMITATIONS: Leg muscle activity was measured during
static exercises only. CONCLUSIONS: Adding WBV during exercise significantly
increased EMG activity in the TA and BF muscles. The EMG responses to WBV in the
paretic and nonparetic 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.
CI - (c) 2015 American Physical Therapy Association.

Langue : ANGLAIS