One Session Increases Muscle Strength

Clin Rehabil. 2007 Sep;21(9):782-93.

One session of whole body vibration increases voluntary muscle strength transiently in patients with stroke.

Tihanyi TK, Horváth M, Fazekas G, Hortobágyi T, Tihanyi J.

Source:  Semmelweis University, and Department of Rehabilitation Medicine, Saint John Hospital Budapest, Hungary.



To determine the effect of whole body vibration on isometric and eccentric torque and electromyography (EMG) variables of knee extensors on the affected side of stroke patients.

DESIGN:  A randomized controlled study.

SETTING:  A rehabilitation centre.

SUBJECTS:  Sixteen patients (age 58.2+/-9.4 years) were enrolled in an inpatient rehabilitation programme 27.2+/-10.4 days after a stroke.

INTERVENTIONS:  Eight patients were randomly assigned to the vibration group and received 20 Hz vibration (5 mm amplitude) while standing on a vibration platform for 1 minute six times in one session. Patients in the control group also stood on the platform but did not receive vibration.

MAIN MEASURES:  Maximum isometric and eccentric torque, rate of torque development, root-mean-squared EMG, median frequency of vastus lateralis, and co-activation of knee flexors.

RESULTS:  Isometric and eccentric knee extension torque increased 36.6% and 22.2%, respectively, after vibration (P<0.05) and 8.4% and 5.3% in the control group. Vibration increased EMG amplitude 44.9% and the median frequency in the vastus lateralis by 13.1% (all P<0.05) without changes in the control group (10.6% and 3.9%). Vibration improved the ability to generate mechanical work during eccentric contraction (17.5%). Vibration reduced biceps femoris co-activation during isometric (8.4%, ns) and eccentric (22.5%, P<0.05) contraction.

CONCLUSION:  These results suggest that one bout of whole body vibration can transiently increase voluntary force and muscle activation of the quadriceps muscle affected by a stroke.

PMID:  17875558