Published online Sep 18, 2018. doi: 10.5312/wjo.v9.i9.156
Peer-review started: March 29, 2018
First decision: May 2, 2018
Revised: May 20, 2018
Accepted: May 23, 2018
Article in press: May 23, 2018
Published online: September 18, 2018
To investigate the acute effects of sinusoidal and stochastic resonance partial-body vibration in sitting position, including muscle activity, heart rate variability, balance and flexibility.
Fifty healthy participants were assigned randomly to two training conditions: A sinusoidal partial-body vibration (SIN, 8 Hz) or a stochastic resonance partial-body vibration (STOCH, 8 ± 2 Hz). For baseline assessment participants sat on the vibration platform without vibration. Both training conditions consisted of five series of a one-minute vibration training and a one-minute break between them. In this experimental study surface electromyography (EMG) of the erector spinae (ES), one of the back muscles, and heart rate variability (HRV) was measured at baseline and during training. Balance and flexibility were assessed at baseline and immediately after training. Balance was measured with the modified star excursion balance test (mSEBT) and flexibility was assessed through the modified fingertip-to-floor method (mFTF).
Paired sample t-test showed a significant increase in balance that was restricted to STOCH (t = -2.22, P = 0.018; SIN: t = -0.09, P = 0.466). An increase in flexibility was also restricted to STOCH (t = 2.65, P = 0.007; SIN: t = 1.41, P = 0.086). There was no significant change of muscle activity in the ES-EMG in STOCH or SIN conditions. In both training conditions, HRV decreased significantly, but remained in a low-load range (STOCH: t = 2.89, P = 0.004; SIN: t = 2.55, P = 0.009).
In sitting position, stochastic resonance partial-body vibration can improve balance and flexibility while cardiovascular load is low. STOCH can be a valuable training option to people who are unable to stand (e.g., people, who are temporarily wheelchair-bound).
Core tip: This experimental study shows an immediate improvement of balance and flexibility after one training session of stochastic resonance partial-body vibration (STOCH) in sitting position. STOCH in sitting position is a promising complement to stochastic resonance whole-body vibration (SR-WBV) in standing position, especially for individuals who are unable to do SR-WBV (e.g., people who are temporarily wheelchair-bound).