Effects of vibrations on gastrocnemius medialis tissue oxygenation.
OBJECTIVE
Whole-body vibrations are known to affect muscle activity and tissue oxygenation, but some energetic aspects are still poorly understood. This study investigates the effects of whole-body vibration on gastrocnemius muscle oxygen utilization rate and tissue oxygenation dynamics during exercise.


METHODS
The effects of vibration on gastrocnemius medialis muscle oxygenation were investigated during a dynamic exercise on a sample of 16 active male subjects (age = 26.3 ± 5.1 yr, mass = 71.2 ± 4.8 kg (mean ± SD)). Both arterially occluded (AO) and nonoccluded (N/O) conditions were investigated. Tissue oxygenation was monitored with a near-infrared spectrometer. Oxygen utilization rate and tissue oxygenation recovery were computed as the slopes of the regression line of the oxygenation decay and recovery, respectively. A fast Fourier transform (FFT) was used to determine the frequency spectrum of the oxygen saturation data. EMG activity was monitored using bipolar EMG electrodes. A windowed root mean square analysis was used to monitor the amplitude of the EMG signal.


RESULTS
A statistically significant increase of 15% (P < 0.05) in oxygen utilization rate was found for the vibration condition in the AO leg but not in the N/O leg. The oxygenation recovery rate for the vibration condition was 34% higher (P < 0.05) than that for the control condition. A low-frequency periodic oscillation (T ≈ 10 s) in the tissue oxygenation data was determined from the FFT spectrum. A statistically significant decrease in the oscillation frequency was noticed for the vibration condition compared with the control.


CONCLUSIONS
Vibrations increased the oxygen utilization rate during a dynamic exercise. The oxygenation recovery rate increased with vibrations. The low-frequency oscillation of the oxygenation was attributed to the periodic changes in tissue blood flow, and this seems to be influenced by vibrations.
Coza
Aurel
A
Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Canada. acoza@kin.ucalgary.ca
Nigg
Benno M
BM
Dunn
Jeff F
JF
D000328:Adult; D004576:Electromyography; D015444:Exercise; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism*; D010100:Oxygen / Q000097:blood / Q000378:metabolism*; D010101:Oxygen Consumption; D014732:Vibration; D055815:Young Adult
D010100:Oxygen