The Effect of Whole-body Vibration on Muscle Activity in Active and Inactive Subjects

Abstract

The purpose of this study was to compare lower limb muscle activity between physically active and inactive individuals during whole-body vibration exercises. Additionally, transmissibility of the vertical acceleration to the head was quantified. 30 active and 28 inactive participants volunteered to stand in a relaxed (20°) and a squat (60°) position on a side-alternating WBV platform that induced vibrations at 16 Hz and 4 mm amplitude. Surface electromyography (sEMG) was measured in selected lower limb muscles and was normalized to the corresponding sEMG recorded during a maximal voluntary contraction. The vertical acceleration on the head was evaluated and divided by the vertical platform acceleration to obtain transmissibility values. Control trials without vibration were also assessed. The outcomes of this study showed that (1) WBV significantly increased muscle activity in the active (absolute increase: +7%, P <0.05) and inactive participants (+8%, P <0.05), (2) with no differences in sEMG increases between the groups (P>0.05). However, (3), transmissibility to the head was greater in the active (0.080) than the inactive participants (0.065, P <0.05). In conclusion, inactive individuals show similar responses in sEMG due to WBV as their active counterparts, but are at lower risk for potential side-effects of vibration exposure.

Muscle activity and vibration transmissibility during whole‐body vibration in chronic stroke

“…Moreover, higher WBV intensities (1.11‐7.00 g) led to higher levels of muscle activation in bilateral MG (paretic: +54.8%‐269.3%; non‐paretic: +49.3%‐301.0%), TA (paretic: +43.7%‐221.9%; non‐paretic: +93.4%‐573.4%), and MH (paretic: +129.7%‐230.4%; non‐paretic: +44.6%‐136.5%). These values are generally in line with those reported in previous studies in young healthy adults, older adults, and stroke patients when using a similar EMG processing method. The degree of muscle activation induced by WBV was higher than that in the young healthy population.…”

“…The muscle‐tuning theory may explain why the same vibration protocol may lead to varying degrees of muscle activity augmentation in different muscles. The increased muscle activity may in turn damp the vibration and reduce the impact forces, thereby minimizing the potential risk of damage to other body structures …”

“…Several studies have reported an increase in lower limb muscle activity during exposure to WBV in healthy young adults, older adults, and stroke survivors, as measured by surface electromyography (EMG). However, randomized controlled trials on the effect of WBV treatment on leg muscle strength have yielded mixed results .…”

“…The inconsistency in results may be due to the use of different WBV settings. Indeed, previous studies on healthy young adults indicated that muscle activation induced by WBV was highly dependent on the WBV frequency, WBV amplitude, additional load, posture, and a combination of these factors …”

The Effects of Whole Body Vibration Exercise on Jump Performance and Quadriceps Muscle Activation in Soccer Player

“…Thirty Hz frequency can affect positively in human body due to increasing exercise function, energy metabolism and blood flow rate by attentively increasing of growth hormone, 31 the action potential can be increased and fatigability can be decreased by increasing excitability of alpha motor neuron and contractible protein sensitivity with increasing inputs of afferent fibers for muscle activation. 32 Lienhard et al 28 suggested that the various change of position considering the physical capability of subjects can be effectively applied muscle activation due to observation of significant increasing for leg muscle activation improvement with a position with bending 60 degree, as a result of WBV intervention using 16 Hz for position of knee joint with bending 60 degree and comfortability standing position.…”