Characterisation of the transient mechanical response and the electromyographical activation of lower leg muscles in whole body vibration training

Acute neuromuscular responses to whole-body vibration in healthy individuals: A systematic review

Whole-body vibration (WBV) training has been employed alongside conventional exercise like resistance training to enhance skeletal muscle strength and performance. This systematic review examines the evidence regarding the effect of WBV on muscle activity, strength, and performance in healthy individuals. The Academic Search Ultimate, CINAHL, Cochrane CENTRAL, PubMed, ProQuest One Academic and SCOPUS databases were searched from 1990 to April 2023 to retrieve relevant studies. Methodological quality was assessed using the Modified Downs and Black checklist, while the level of evidence was evaluated through the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) tool. Even though the quality of the included studies was moderate to high, the level of evidence was very low owing to serious concerns with three or more GRADE domains (risk of bias, inconsistency, indirectness, imprecision, and publication bias) for each outcome of interest across studies. The review suggests that in WBV training, using moderate to high vibration frequencies (25-40 Hz) and high magnitudes (3-6 mm) can enhance muscle activation and strength in pelvis and lower limb muscles. However, findings regarding WBV effect on muscle performance measures were inconsistent. Future research with robust methodology is necessary in this area to validate and support these findings.

Sensorimotor recalibration of postural control strategies occurs after whole body vibration

Efficient postural control results from an effective interplay between sensory feedbacks integration and muscle modulation and can be affected by ageing and neuromuscular injuries. With this study, we investigated the effect of whole-body vibratory stimulation on postural control strategies employed to maintain an upright posture. We explored both physiological and posturography metrics, through corticomuscular and intramuscular coherence, and muscle networks analyses. The stimulation disrupts balance in the short term, but leads to a greater contribution of cortical activity, necessary to modulate muscle activation via the formation of (new) synergies. We also observed a reconfiguration of muscle recruitment patterns that returned to pre-stimulation levels after few minutes, accompanied by a slight improvement of balance in the anterior-posterior direction. Our results suggest that, in the context of postural control, appropriate mechanical stimulation is capable of triggering a recalibration of the sensorimotor set and might offer new perspectives for motor re-education.

Effect of Whole-Body Vibration Exercise on Hamstrings-to-Quadriceps Ratio, Walking Performance, and Postural Control in Children With Hemiparetic Cerebral Palsy: A Randomized Controlled Trial

OBJECTIVE

The purpose of this study was to investigate the effect of whole-body vibration (WBV) exercises combined with traditional physiotherapy on the hamstrings-to-quadriceps (H:Q) ratio, walking ability, and control of posture in children with hemiparetic cerebral palsy (CP).

METHODS

A total of 34 children with spastic hemiparetic CP (boys and girls) participated in this 2-arm, parallel, randomized controlled trial. The inclusion criteria were spasticity ranging from 1 to 1+, gross level skills (I and II), at least 1 meter tall, standing alone, and walking forward and backward. They were randomly allocated to the control group (traditional physiotherapy) and study group and were treated by the same physiotherapy program combined with WBV training (3 times per week for 2 successive months). Quadriceps and hamstring muscle strength, walking performance, and postural control were evaluated before and after intervention by a blinded assessor.

RESULTS

The post-intervention values of the hamstring and quadriceps muscle force, gross motor function, and stability indices of the 2 groups were higher than the pre-values (P < .05). In addition, the post-values of the study group were higher than those of the control group (P < .05). Regarding the H:Q ratio, there was no significant difference between pre-values or the post-values of both groups (P = .948 and P = .397, respectively). There were no significant differences between the pre- and post-values of each group (P = .500 and P = .195, respectively).

CONCLUSION

Eight weeks of WBV training combined with traditional physiotherapy was more effective than traditional physiotherapy alone in improving walking ability and postural control. Furthermore, the combined intervention strengthened the quadriceps and hamstring muscles, with no change in the H:Q ratio in children with hemiparetic CP.