Effects of combined whole body vibration and resistance training on lower quadrants electromyographic activity, muscle strength and power in athletes

Integrative function of proprioceptive system in the acute effects of whole body vibration on the movement performance in young adults

Background

The proprioceptive system coordinates locomotion, but its role in short-term integration and recovery of motor activity in imbalance of motor patterns and body remains debated. The aim of this study is investigating the functional role of proprioceptive system in motor patterns and body balance in healthy young adults.

Methods

70 participants (aged 20.1 ± 0.3) were divided into experimental groups EG1 (n = 30), EG2 (n = 30), control group (CG, n = 10). EG1 performed single WBV session on Power Plate (7 exercises adapted to Functional Movement Screen (FMS). EG2 performed single session of FMS Exercises (FMSE). CG didn't perform any physical activity. All participants performed pre- and post-session of FMS and stabilometric measurements.

Results

FMS total score in EG1 increased by 2.0 ± 0.2 (p0 < 0.001), this was significantly differed (p0 < 0.001) from EG2 and CG. Acute effects of WBV and FMSE on rate of change and standard deviation (SD) of pressure center (COP) were shown in all groups during Static Test (p0 < 0.01). SD increased (p0 < 0.01) in Given Setting Test in EG1 and EG2, and in Romberg Test (p0 < 0.001) in EG1. Length, width and area (p0 < 0.01) of confidence ellipse, containing 95% of the statokinesiogram points, decreased in Static Test in EG1; width and area (p0 < 0.01) decreased in EG2 group. Significant (p0 < 0.01) decrease in Given Setting Test was in EG1, and significant (p0 < 0.01) increase was in Romberg Test (open eyes) in CG. Maximum amplitude of COP oscillations: significantly (p0 < 0.01) decreasing along X and Y axes in EG1 and EG2, and along Y axis in CG during Static Test; along Y axis (p0 < 0.01) in all groups during Given Setting Test. Significant differences were identified (p0 < 0.01) in calculated energy consumption for COP moving during all stabilometric tests. However, inter-group differences in COP after acute WBV and FMSE sessions have not been identified.

Conclusions

Acute WBV session eliminates the deficits in motor patterns which is not the case after acute FMSE session, which, according to our integrative movement tuning hypothesis, is due to high activation of integrative function of proprioceptive system. Efficacy of WBV and FMSE on COP performance indicates a high sensitivity of postural control to different levels of proprioceptive system activity.

Adding mechanical vibration to a half squat with different ballasts and rhythms increases movement variability

The aim of this study was to determine whether whole body vibration increases movement variability while performing a half squat with different ballasts and rhythms through entropy. A total of 12 male athletes (age: 21.24 ± 2.35 years, height: 176.83 ± 5.80 cm, body mass: 70.63 ± 8.58 kg) performed a half squat with weighted vest, dumbbells and bar with weights suspended with elastic bands, with and without vibration at the squat rhythm of 40 and 60 bpm. Each ballast corresponded to 15% of the body mass. The movement variability was analysed by calculating the sample entropy of the acceleration signal, recorded at the waist using an accelerometer. With vibration, differences were found between weighted vest and dumbbells (t(121) = -8.81, p < 0.001 at 40 bpm; t(121) = -8.18, p < 0.001 at 60 bpm) and between weighted vest and bar at both rhythms (t(121) = -8.96, p < 0.001 at 40 bpm; t(121) = -8.83, p < 0.001 at 60 bpm). Furthermore, a higher sample entropy was obtained at 40 bpm with all ballasts (t(121) = 5.65, p < 0.001 with weighted vest; t(121) = 6.27, p < 0.001 with dumbbells; t(121) = 5.78, p < 0.001 with bar). No differences were found without vibration. These findings reveal that adding mechanical vibration to a half squat produces a non-proportional increase in movement variability, being larger when the ballast is placed on the upper limbs and when performed at a slow rhythm.

Acute effects of blood flow restriction with whole-body vibration on sprint, muscle activation and metabolic accumulation in male sprinters

Purpose: The aim of this study was to explore the acute effects of Blood Flow Restriction Training (BFRT), Whole-Body Vibration (WBV), and BFRT + WBV on the 20 m sprint, muscle activation, and metabolic accumulation in male sprinters.

Method: Sixteen male sprinters randomly performed BFRT, WBV, or BFRT + WBV interventions with 72 h intervals. Electromyography (EMG) signals were collected before and during interventions. Fingertip blood was taken before, immediately after, and 15 min after the intervention. 20 m sprint was performed before and 3 min after the intervention.

Results: 1) 0–10m and 0–20 m sprint performance were significantly improved after WBV and BFRT + WBV interventions (p &lt; 0.05), 0–20 m sprint performance was significantly improved after all three interventions (p &lt; 0.05), 2) After BFRT + WBV intervention, the EMG amplitude of the vastus lateralis and soleus were significantly improved. Greater increases in EMG activity of the tibialis anterior muscle (p &lt; 0.05)and blood lactate (p &lt; 0.05)were observed following BFRT intervention compared to BFRT + WBV intervention.

Conclusion: For sprint performance, BFRT and WBV had similar post-activation enhancement effects to BFRT + WBV, and the metabolic accumulation immediately following the BFRT were higher than that following BFRT + WBV in male sprinters.

Effects of Vibration Resistance Exercises on EMG and Skeletal Muscle Hemodynamics

Objectives: Past studies show that vibration can stimulate muscle activity and improve muscle performance. However, further verification is needed on the effects of different vibration frequencies combined with different muscle strength exercise intensities on EMG activity and skeletal muscle hemodynamics. Methods: We recruited 27 male college athletes for 40%, 60%, and 80% maximum voluntary contraction (MVC) tests at the vibration frequencies of 0 Hz, 10 Hz, 20 Hz, and 30 Hz. We collected EMG activity signals using wireless EMGs and skeletal muscle hemodynamic parameters using a near-infrared spectrometer. Results: At an 80% MVC intensity of the rectus femoris, the mean, peak, and area of EMG at 30 Hz were significantly increased, compared with those at 0 Hz. At a 40% MVC intensity with vibration frequencies of 10 Hz, 20 Hz, and 30 Hz, the HHb of skeletal muscles was significantly increased, while the O2Hb and TSI were significantly decreased, compared with those at 0 Hz. Conclusions: We conclude that high frequency and strongly vibrated muscle strength exercise can improve EMG activity, while vibration and low-intensity muscle strength exercise could increase the oxygen consumption of skeletal muscles.

Effects of different exercise training modes on muscle strength and physical performance in older people with sarcopenia: a systematic review and meta-analysis

OBJECTIVE

We conducted a systematic review and meta-analysis to clarify the effects of different exercise modes (resistance training [RT], whole body vibration training [WBVT], and mixed training [MT, resistance training combined with other exercises such as balance, endurance and aerobic training]) on muscle strength (knee extension strength [KES]) and physical performance (Timed Up and Go [TUG], gait speed [GS] and the Chair Stand [CS]) in older people with sarcopenia.

METHOD

All studies published from January 2010 to March 2021 on the effects of exercise training in older people with sarcopenia were retrieved from 6 electronic databases: Pubmed, Cochrane Library, Embase, Web of Science, the China National Knowledge Infrastructure (CNKI), and Wanfang Database. Two researchers independently extracted and evaluated studies that met inclusion and exclusion criteria. Pooled analyses for pre- and post- outcome measurements were performed using Review Manager 5.4 with standardized mean differences (SMDs) and fixed-effect models.

RESULT

Twenty-six studies (25 randomized controlled trails [RCTs] and one non-randomized controlled trail) were included in this study with 1191 older people with sarcopenia (mean age 60.6 ± 2.3 to 89.5 ± 4.4). Compared with a control group, RT and MT significantly improved KES (RT, SMD = 1.36, 95% confidence intervals [95% CI]: 0.71 to 2.02, p < 0.0001, I2 = 72%; MT, SMD = 0.62, 95% CI: 0.29 to 0.95, p = 0.0002, I2 = 56%) and GS (RT, SMD = 2.01, 95% CI: 1.04 to 2.97, p < 0.0001, I2 = 84%; MT, SMD = 0.69, 95% CI: 0.29 to 1.09, p = 0.008, I2 = 81%). WBVT showed no changes in KES (SMD = 0.65, 95% CI: - 0.02 to 1.31, p = 0.06, I2 = 80%) or GS (SMD = 0.12, 95% CI: - 0.15 to 0.39, p = 0.38, I2 = 0%). TUG times were significantly improved with all exercise training modes (SMD = -0.66, 95% CI: - 0.94 to - 0.38, p < 0.00001, I2 = 60%). There were no changes in CS times with any of the exercise training modes (SMD = 0.11, 95% CI: - 0.36 to 0.57, p = 0.65, I2 = 87%).

CONCLUSIONS

In older people with sarcopenia, KES and GS can be improved by RT and MT, but not by WBVT. All three training modes improved TUG times, but not improved CS times.