Effects of whole body vibration training and mental training on mobility, neuromuscular performance, and muscle strength in older men

Combined Effect of HF-rTMS and Whole-Body Vibration Exercise on Cognitive Efficiency in Esports Players With or Without Sedentary Behaviors: A Randomized Controlled Trial

BACKGROUND

The present study investigated the effects of high-frequency repetitive transcranial magnetic stimulation (HF-rTMS), whole-body vibration training (WBVT), and a combination of HF-rTMS and WBVT interventions on cognitive performance in esports players with or without sedentary behaviors.

METHODS

A total of 128 participants, including sedentary and non-sedentary esports players, were randomly assigned to the HF-rTMS group, the WBVT group, the HF-rTMS + WBVT group, or the control group. The interventions were administered daily for 2 weeks, and pretest, mid-test, and posttest assessments were conducted. Cognitive function was assessed using the Digit Symbol Substitution Test (DSST) for response time and accuracy, and gaming performance was measured using first-person shooter (FPS) scores.

RESULTS

At baseline, sedentary players demonstrated significantly increased response time in DSST compared to non-sedentary participants. The interventions, both HF-rTMS and WBVT, significantly enhanced cognitive processing speed and accuracy, with these improvements being more pronounced in sedentary esports players compared to non-sedentary esports players. Notably, the combination of HF-rTMS and WBVT was found to be the most effective in boosting cognitive performance among these interventions. Furthermore, FPS scores showed an overall increase in all intervention groups in both sedentary and non-sedentary esports players, and the combination of HF-rTMS and WBVT showed the most pronounced effect on in gaming performance.

CONCLUSION

The study demonstrated that sedentary behavior had a detrimental effect on the cognitive function in esports players. Furthermore, HF-rTMS and WBVT, especially in combination, effectively enhanced cognitive performance in esports players, with a more pronounced effect in those with sedentary lifestyles. These findings suggested potential strategies for cognitive enhancement in the esports context, highlighting the need for tailored interventions based on individual lifestyle factors.

Effects of low-frequency vibration training on walking ability and body composition among older adults: a randomized controlled trial

Background

As life expectancy rises, age-related decline in mobility and physical function poses challenges for older adults. While traditional exercise can help, limitations and injury risks persist. This study explores low-frequency vibration training as a potential alternative to improve walking ability and body composition in older adults.

Methods

A lottery was used to randomly assign 50 participants (mean age 80.08 years) to either a vibration group (n = 25, 10 males, 15 females) or a control group (n = 25, 11 males, 14 females). While the control group continued their regular daily schedule, the vibration group completed 8 weeks of low-frequency vibration training (frequency: 4-13 Hz; amplitude: two mm), three sessions per week, with each session lasting 20-30 minutes. The walk ability was assessed using the 30-second Chair Stand Test (30-s CST), Timed Up and Go (TUG), and six-meter (six m) walk speed, while body composition was measured via body mass index (BMI), body fat percentage, and waist circumference (WC), hip circumference (HC), and waist-to-hip ratio (WHR).

Results

Low-frequency vibration training significantly increased walking speed in the six m walk speed (F (1,36) = 4.50, p = 0.04, η p 2 = 0.11) and TUG (z =  - 2.72, p = 0.007), compared with the control group. Observed improvements on the 30-s CST were not statistically significant (F (1,36) = 0.05, p = 0.81, η p 2 = 0.002). In the WC, the effect of time (F (1,36) = 7.19, p = 0.01, η p 2 = 0.16) was significant. The main effect of the group for HC (F (1,36) = 0.06, p = 0.80, η p 2 = 0.002) and WHR (F (1,36) = 2.00, p = 0.16, η p 2 = 0.05) were not significant, but the interaction effects for HC (F (1,36) = 6.37, p = 0.01, η p 2 = 0.15) and WHR (F (1,36) = 9.08, p = 0.005, η p 2 = 0.20) were significant. However, the intervention showed no statistically significant effects on BMI and body fat percentage.

Conclusion

Low-frequency vibration training significantly enhanced walking speed and WHR in older adults. This low-intensity intervention is especially beneficial for those with exercise limitations or a high risk of injury. Although its effects on BMI and body fat percentage were limited, the study offers valuable insights for developing personalized vibration training programs.

Effects of mirror neuron activation therapies on functionality in older adults: Systematic review and meta-analysis

PURPOSE

To identify the effects of mirror neuron activation (MNAT) combined or not with physical exercise (PE) in healthy older adults, on functionality, balance, gait velocity and risk of falls.

METHODS

A systematic electronic search was performed in PubMed/MEDLINE, Cochrane, and Embase databases.

RESULTS

Thirteen randomized controlled trials were included in the qualitative analysis, and eleven in the quantitative analysis. All studies showed fair to high quality and the most frequent high-risk bias was "Blinding of participants and personnel". Compared to the control condition, higher improvement was shown in older people who received MNAT, on functionality (1.57 [0.57, 2.62], balance (1.95 [1.32, 2.572]), and gait velocity (1.20 [0.30, 2.11]). Compared to PE, MNAT combined with PE does not improve functionality. More studies are needed to assess MNAT effectiveness in the rest of the outcomes.

CONCLUSIONS

Neuron system activation through MNAT improves relevant abilities in older adults, with better results when including functional activities. However, the beneficial effects on these variables of adding MNAT to a PE program are controversial.

Action observation with motor simulation improves reactive stepping responses following strong backward balance perturbations in healthy young individuals

BACKGROUND AND OBJECTIVE

Adequate reactive steps are critical for preventing falls following balance perturbations. Perturbation-based balance training was shown to improve reactive stepping in various clinical populations, but its delivery is labor-intensive and generally uses expensive equipment. Action observation of reactive steps with either motor imagery (AOMI) or motor simulation (AOMS) are potential alternative training modalities. We here aimed to study their effects on reactive stepping performance.

METHODS

Sixty healthy young subjects were subjected to forward platform translations that elicited backward reactive steps. The AOMI group (n = 20) was tested after AOMI of an actor's reactive steps, while the AOMS group (n = 20) additionally stepped along with the actor. The control group (n = 20) was tested without any prior observation. Our primary outcome was the step quality of the first trial response, as this best represents a real-life loss-of-balance. Step quality was quantified as the leg angle with respect to the vertical at stepping-foot contact. We also studied single step success rates and reactive step quality across repeated trials.

RESULTS

Reactive step quality was significantly better in the AOMI and AOMS groups than in the control group, which differences coincided with a twofold higher single step success rate. Reactive step quality improved upon repeated trials in all groups, yet the AOMS group needed the fewest repetitions to reach plateau performance.

SIGNIFICANCE

The present results demonstrate that both AOMI and AOMS improved first and repeated trial reactive stepping performance. These findings point at the potential applicability of these concepts for home-based reactive balance training, for instance in serious games, with overt movements (AOMS) possibly having some benefits over mental imaginations (AOMI). Whether similar beneficial effects also emerge in the target populations of balance-impaired individuals remains to be investigated.

Effects of Whole-Body Vibration Training on Lower Limb Muscle Strength and Physical Performance Among Older Adults: A Systematic Review and Meta-analysis

OBJECTIVE

To evaluate the effects of whole-body vibration training (WBVT) on lower limb muscle strength and physical performance in older adults.

DATA SOURCES

Web of Science, PubMed, Cochrane Library, and MEDLINE databases were searched for papers published in English, from January 1, 2000, to May 30, 2022.

STUDY SELECTION

Randomized controlled trials of WBVT in older adults (mean age, 65 years or older) published in English. The Physiotherapy Evidence Database Scale was used to assess the quality of the selected studies.

DATA EXTRACTION

Two investigators independently assessed articles according to the evaluation criteria. Differences between investigator assessments were resolved by consulting a third investigator before reassessment.

DATA SYNTHESIS

Systematic review of 18 randomized controlled studies found that WBVT produced significant improvements in lower limb muscle strength and physical performance among older adults. We used the Cochrane Collaboration method to assess risk of bias and RevMan version 5.4a to extract means and calculate SDs. WBVT significantly improved knee strength (standard mean difference [SMD]=0.72, 95% confidence interval [CI] [0.38, 1.07], P<.0001, I2=58%) and explosive power (SMD=0.47, 95% CI [0.10, 0.83], P=.01, I2=0%) among older adults. Significant improvements in each physical performance were observed in the sit-to-stand test (SMD=0.57, 95% CI [0.30, 0.84], P<.0001, I2=35%), the subgroup of studies that evaluated balance with timed Up and Go test, SMD was 0.53 (95% CI [0.19, 0.88], P=.002, I2=56%) and the Tinetti total score, SMD was 0.72 (95% CI [0.04, 1.41], P=.04, I2=81%), walking speed (SMD=0.46, 95% CI [0.14, 0.77], P=.005, I2=49%), and walking endurance (SMD=0.43, 95% CI [0.02, 0.85], P=.04, I2=24%).

CONCLUSIONS

WBVT may be an effective intervention to improve lower limb muscle strength and physical performance in older adults. Tinetti total score remains controversial and warrants assessment in future high-quality randomized controlled trials.

Impacts of Whole-Body Vibration on Muscle Strength, Power, and Endurance in Older Adults: A Systematic Review and Meta-Analysis

BACKGROUND

Randomized clinical trials (RCTs) were conducted to identify the effectiveness of whole-body vibration (WBV) on strength, power, and muscular endurance in older adults. However, the results of different studies are contradictory.

OBJECTIVE

To verify the impacts of the WBV on strength, power, and muscular endurance in older adults.

METHODS

The search was carried out in PubMed, Embase, CENTRAL, CINAHL, SPORTDiscus, Web of Science, LILACS and PEDro databases. Methodological quality was assessed using the PEdro scale. Meta-analysis calculations were performed using the standardized mean difference, comparing WBV with control groups and WBV with other types of exercise.

RESULTS

Thirty-four studies were included in the current systematic review. Most studies (56%) had low methodological quality (PEDro score < 6). WBV, compared with control groups, has significant effects on muscle strength of knee extensors and flexors, lower limb extensors, and ankle plantar flexors. There were no differences between WBV and other types of exercise. Subgroup analyzes demonstrated that, in general, the significant results observed in the primary analyzes were not dependent on body position during vibration, kind of vibration, cumulative dose or magnitude of WBV.

CONCLUSION

WBV was effective in increasing lower limb muscle strength. However, no significant results were observed for upper limb strength, lower limb power, and lower and upper limb muscle endurance in older adults. However, more studies are needed to better understand the physiological impacts of WBV in older.

The Effect of Motor Imaginary Combined with Transcranial Direct Current Stimulation (tDCS) on Balance in Middle-Aged Women with High Fall Risk: A Double-Blind Randomized Controlled Trial

Introduction. The risk of falling and its subsequent injuries increases with aging. Impaired balance and gait are important contributing factors to the increased risk of falling. A wide range of methods was examined to improve balance, but these interventions might produce small effects or be inapplicable for this population. The current study aimed at investigating the effect of motor imaginary (MI) training combined with transcranial direct current stimulation (tDCS) over the cerebellum on balance in middle-aged women with high fall risk. Methods. Thirty subjects aged 40-65 years old were divided into two groups including intervention ( $n=15$ ) and sham control ( $n=15$ ). The participants completed a 4-week program 3 times per week. The intervention group performed MI training combined with tDCS over the cerebellum, and the control group performed MI training combined with sham tDCS over the cerebellum. Static and dynamic balance were measured at baseline and after completing the 4-week program using balance error scoring system (BESS) and Y balance testing, respectively. Result. A one-way analysis of covariance and paired $t$ -tests were used to analyze the data. Significant improvement was observed in both balance tests in the intervention group after the implementation of the 4-week intervention program compared to the control group. The within-group analysis showed that both static and dynamic balance improved significantly from the baseline values only in the intervention group ( $p<0.05$ ) and not in the control group ( $p>0.05$ ). Conclusion. The results of the study indicate that MI training combined with tDCS over the cerebellum can lead to balance improvement in middle-aged women with high fall risk.

Elderly may benefit more from motor imagery training in gaining muscle strength than young adults: A systematic review and meta-analysis

Objective

The current review was aimed to determine the effectiveness of mental imagery training (MIT) on the enhancement of maximum voluntary muscle contraction (MVC) force for healthy young and old adults.

Data sources

Six electronic databases were searched from July 2021 to March 2022. Search terms included: "motor imagery training," "motor imagery practice," "mental practice," "mental training," "movement imagery," "cognitive training," "strength," "force," "muscle strength," "performance," "enhancement," "improvement," "development," and "healthy adults."

Study selection and data extraction

Randomized controlled trials of MIT in enhancing muscle strength with healthy adults were selected. The decision on whether a study met the inclusion criteria of the review was made by two reviewers independently. Any disagreements between the two reviewers were first resolved by discussion between the two reviewers. If consensus could not be reached, then it would be arbitrated by a third reviewer.

Data synthesis

Twenty-five studies including both internal MIT and external MIT were included in meta-analysis for determining the efficacy of MIT on enhancing muscle strength and 22 internal MIT were used for subgroup analysis for examining dose-response relationship of MIT on MVC.

Results

MIT demonstrated significant benefit on enhancing muscle strength when compared with no exercise, Effect Size (ES), 1.10, 95% confidence interval (CI), 0.89-1.30, favoring MIT, but was inferior to physical training (PT), ES, 0.38, 95% CI, 0.15-0.62, favoring PT. Subgroup analysis demonstrated that MIT was more effective for older adults (ES, 2.17, 95% CI, 1.57-2.76) than young adults (ES, 0.95, 95% CI, 0.74-1.17), p = 0.0002, and for small finger muscles (ES, 1.64, 95% CI, 1.06-2.22) than large upper extremity muscles (ES, 0.86, 95% CI, 0.56-1.16), p = 0.02. No significant difference was found in the comparison of small finger muscles and large lower extremity muscles, p = 0.19 although the ES of the former (ES, 1.64, 95% CI, 1.06-2.22) was greater than that of the later (ES, 1.20, 95%, 0.88-1.52).

Conclusion

This review demonstrates that MIT has better estimated effects on enhancing MVC force compared to no exercise, but is inferior to PT. The combination of MIT and PT is equivalent to PT alone in enhancing muscle strength. The subgroup group analysis further suggests that older adults and small finger muscles may benefit more from MIT than young adults and larger muscles.

Effects of whole-body vibration training with different frequencies on the balance ability of the older adults: a network meta-analysis

Purpose: To compare the effects of whole-body vibration training (WBVT) with different frequencies on the balance ability of older adults. Methods: Randomized controlled trials (RCTs) on the WBVT interventions on balance ability in older adults were searched through PubMed, Web of Science, The Cochrane Library, ProQuest, Embase, Opengrey, China National Knowledge Infrastructure (CNKI), Wanfang, and China Science and Technology Journal Database (CSTJ) databases from the establishment of the database to August 2022, and all literature that met the PICOS (Participants, Intervention, Comparison, Outcomes, Study design) criteria were enrolled. Two reviewers screened and assessed the methodological quality of the included literature according to the physiotherapy evidence database (PEDro) scale criteria. Statistical analysis was performed using Stata 14.0 software after data extraction. Results: Twenty-five RCTs with a total of 1267 subjects were finally included. The results of the pairwise comparison of the Network Meta-analysis showed that the Timed Up and Go Test (TUGT) values of Low-frequency whole-body vibration training (LF-WBVT) was lower than the placebo and traditional rehabilitation groups, and the difference was statistically significant [WMD = -1.37, 95% CI (-2.53, -0.20)] [WMD = -1.84, 95% CI(-3.17,-0.51)]. The Five-repetition Sit-to-Stand Test (5STS) values of LF-WBVT, Medium-frequency whole-body vibration training (MF-WBVT), and High-frequency whole-body vibration training (HF-WBVT) were lower than the placebo and traditional rehabilitation groups, but none of them were statistically significant. In addition, the TUGT and 5STS values of HF-WBVT had a tendency to be lower than those of LF-WBVT and MF-WBVT, but neither of them was statistically different. The cumulative probability ranking results of both TUGT and 5STS showed that HF-WBVT was the best protocol. Conclusion: Current evidence shows that HF-WBVT may be the best protocol for improving balance in older adults. Due to the study's limitations, the conclusion obtained in this study still needs to be further confirmed by more high-quality studies. Systematic Review Registration: [https://www.crd.york.ac.uk/PROSPERO/], identifier [CRD42021250405].

Effects of whole-body vibration at different periods on lumbar vertebrae in female rats

The current study aimed to investigate the effects of whole-body vibration (WBV) before and after ovariectomy on lumbar vertebrae, and to observe whether the positive effects of WBV before and after ovariectomy on lumbar vertebrae in rats could be maintained after vibration stopped. Three-month-old female rats were divided into four groups (n = 45/group): control (CON), ovariectomy (OVA), WBV before ovariectomy (WBV-BO), and WBV after ovariectomy (WBV-AO) groups. For 1-8 weeks, WBV-BO group was subjected to vertical WBV. At the 9th week, the rats in WBV-BO, WBV-AO, and OVA groups were ovariectomized. During 11-18 weeks, WBV-AO group was subjected to vibration. For 19-26 weeks, no intervention was done for rats. The lumbar vertebrae were examined by Micro-CT, compressive test, creep test, and microindentation test. At the 8th week, the displacement of the L1-L2 annulus fibrosus in WBV-BO group was 18% smaller compared with CON group (p<0.05). At the 18th week, the elastic modulus of the L5 vertebral body in WBV-BO and WBV-AO groups was 53% and 57% higher than that in CON group, respectively (p<0.05); the displacement of the L1-L2 annulus fibrosus in WBV-BO group was 25% smaller than those in the other groups (p<0.05). At the 26th week, there was no significant difference in the displacement of the L1-L2 annulus fibrosus between WBV-BO group and other groups (p>0.05); the elastic modulus of the L5 vertebral body had no significant difference between WBV-AO group and CON group (p>0.05). Our results demonstrated that WBV before ovariectomy effectively prevented disc degeneration with significant effects up to 8 weeks after ovariectomy. The vertebral mechanical properties could be significantly improved by WBV after ovariectomy, but the residual effect did not maintain after WBV stopped.

Global Public Health Emphasis Is Imperative to Improve Quality of Life and Reduce Morbidity for the Geriatric Population in Low and Middle-Income Countries

The Article Abstract is not available.  

Resistance circuit training combined with hypoxia stimulates bone system of older adults: A randomized trial

PURPOSE

Aging leads to gradual irreversible decline in bone mass. As adherence to pharmacological treatment is poor, hypoxia combined with strength training has been suggested for therapeutic benefit for clinical populations. The present study investigated the effects of normobaric cyclic hypoxic exposure combined with resistance circuit training on bone of older adults.

METHODS

Healthy older adults (n = 50) were randomly assigned to a (1) control group (CON; n = 20), who were instructed to continue with their normal daily activities, (2) a group that performed resistance training in normoxia (RTN; n = 17) and (3) a group that performed resistance training in hypoxia (RTH; n = 13). During 24 weeks, RTH group performed resistance training with elastic bands under normobaric hypoxic conditions (16.1 % FiO2). A session of both exercise groups included nine exercises of several body areas with a structure of 3 sets × 12-15 repetitions per exercise, with a 1-minute rest between sets. Bone mineral density (g·cm-2) was measured using dual-energy X-ray absorptiometry. Bone turnover markers of formation (N-terminal propeptide of type I procollagen; PINP) and resorption (C-terminal telopeptide of type I collagen; bCTX) were analysed with enzyme-linked immunosorbent assay (ELISA) microplate reader.

RESULTS

Values of bCTX and bCTX/PINP significant decreased in RTN (bCTX: 47.79 %; p = 0.002; bCTX/PINP: 61.43 %; p = 0.007) and RTH (bCTX: 59.09 %; p = 0.001; bCTX/PINP: 62.61 %; p = 0.003) groups compared with CON group. Change in bone mineral density was not significantly different between groups. Based on clinically significant change, 23 % of the participants in the RTH group reached this value for femoral neck and trochanter bone mineral density (vs 0 % and 6 % of the RTN group, respectively).

CONCLUSIONS

24-Weeks of normobaric cyclic hypoxic exposure combined with resistance circuit training has potential to generate positive effects on bone in older adults.

TRIAL REGISTRATION NUMBER

NCT04281264 (date of registration: February 24, 2020).

Effects of Baduanjin imagery and exercise on cognitive function in the elderly: A functional near-infrared spectroscopy study

Objective

Cognitive function is essential in ensuring the quality of life of the elderly. This study aimed to investigate the effects of Baduanjin imagery and Baduanjin movement (a traditional Chinese health exercise, TCHE) on cognitive function in the elderly using functional near-infrared spectroscopy (fNIRS).

Methods

72 participants with a mean age of 66.92 years (SD = 4.77) were recruited for this study. The participants were randomly assigned to three groups: the Baduanjin imagery, the Baduanjin exercise, and the Control. Stroop task was used to record the accuracy and reaction times, and a near-infrared spectral brain imaging system was used to monitor the brain's oxy-hemoglobin concentration responses.

Results

(1) For the reaction times of Stroop incongruent tasks, the main effect of the test phase (F = 114.076, p < 0.001) and the interaction effect between test phase and group (F = 10.533, p < 0.001) were all significant. The simple effect analysis further demonstrated that the reaction times of the Baduanjin imagery group and Baduanjin exercise group in the post-test was faster than that in the pre-test (ps < 0.001); (2) Analysis of fNIRS data showed the significant interaction effect (F = 2.554, p = 0.013) between the test phase and group in the left dorsolateral prefrontal cortex. Further analysis showed that, during the post-test incongruent tasks, the oxy-Hb variations were significantly higher in participants of the Baduanjin imagery group (p = 0.005) and Baduanjin exercise group (p = 0.002) than in the control group; For the right inferior frontal gyrus, the interaction between the test phase and group was significant (F = 2.060, p = 0.044). Further analysis showed that, during the post-test incongruent tasks, the oxy-Hb variations were significantly higher in participants of the Baduanjin imagery group than in the control group (p = 0.001).

Conclusion

Baduanjin imagery and exercise positively affect cognitive performance; Baduanjin imagery and exercise activated the left dorsolateral prefrontal cortex; Baduanjin imagery activated the right inferior frontal gyrus, while Baduanjin exercise could not.

Effects of aquatic therapy on balance in older adults: a systematic review and meta-analysis

PURPOSE

Balance is a key component of movement for daily activities, especially in older adults. Previous studies examining aquatic therapy as an effective way for improving balance have yielded inconsistent findings. The current systematic review and meta-analysis investigated the effectiveness of aquatic therapy on balance among older adults.

METHODS

Sources include Cochrane Central Register of Controlled Trials, Medline, ISI Web of Science, EBSCO, Embase, Cumulative Index to Nursing and Allied Health Literature, and Scopus. Randomized controlled or cross-over trials published by Feb 2020 were included following pre-determined search and selection criteria. Data extraction was performed by two researchers independently using a pre-determined data extraction form. Methodological quality was assessed by two reviewers using the PEDro scale which was used to rate trials according to criteria such as concealed allocation, blinding, and intention-to-treat analysis. Furthermore, meta-analysis was conducted where possible. This review was registered at PROSPERO CRD42018118382.

RESULTS

Fifteen trials with 385 healthy participants aged 50 or over were included. Results showed that aquatic therapy had a significant effect on dynamic balance (SMD, - 1.13; 95% CI, [- 1.45 to (- 0.82)]; I² = 77%). The analysis indicated that aquatic therapy improved balance ability compared to controls.

CONCLUSIONS

Aquatic therapy has a positive impact on dynamic balance in older adults. However, further high-quality and appropriately powered studies are required to confirm this assertion.

The Essential Role of Stathmin in Myoblast C2C12 for Vertical Vibration-Induced Myotube Formation

Vertical vibration (VV) is a type of whole body vibration, which induces muscle contraction through vibration to improve muscle strength and bone density. However, the mechanism of VV on muscle cell myotube formation is still unclear. In the current study, we aim to clarify the mechanism involved in VV's stimulation of myotube formation. In order to identify the molecules regulated by VV, we performed proteomics analysis including 2D electrophoresis combined with MALDI-TOF/TOF Mass. Stathmin was identified as a high potential molecule responding to VV stimulation, and we found that under VV stimulation, the expression of stathmin gene and protein increased in a time-dependent manner. In addition, we also confirmed that the increase of stathmin stimulated by VV is mediated through the PI3K/Akt pathway. Furthermore, stathmin siRNA significantly down-regulated the expression of myogenic regulatory factor (MRF) MyoD, decorin, and type I collagen (Col-I), and down-regulated the cellular process regulators such as FGF7, TGFBr1 and PAK3. Taken together, our results confirm that under the stimulation of VV, PI3K/Akt and stathmin would be activated, as well as the up-regulation of MRFs, such as FGF7, TGFBr1 and PAK3 to initiate myogenesis. It also showed that the response of MRF to VV stimulation was significantly related to stathmin expression, which also confirmed the importance of stathmin in the entire myotube formation process. This study may provide evidence of stathmin as a biological indicator of VV to increase muscle strength.

Effect of the frequency of weight-free vibration training on the isokinetic strength of knee muscles in juvenile football players

BACKGROUND: Vibration training can affect strength improvement. However, the role of the vibration frequency, in terms of knee muscle strength, is unclear. OBJECTIVE: To evaluate the effect of vibration training with the same amplitude and different frequencies on the isokinetic muscle strength of the knee in juvenile football players. METHODS: Juvenile football players were divided into four groups: low frequency (n= 13, 25 Hz), medium frequency (n= 14, 40 Hz), high frequency (n= 14, 50 Hz), and control (n= 13). The frequency groups completed 12 weeks of weight-free vibration training (three times/week) with the same amplitude (3 mm) but different frequency. RESULTS: Compared with baseline, the peak extension torque of the knee at 60∘/s and 240∘/s increased by 8.4% and 12.9%, respectively, in the medium-frequency group, and by 8.9% and 15.5%, respectively, in the high-frequency group. The extensor endurance (the ability of joint muscle groups to maintain a force output over time) of the knee in the high-frequency group increased by 4.3%. At 12 weeks, the high-frequency group had greater knee extensor endurance than the low- and medium-frequency groups. CONCLUSION: In juvenile football players, weight-free vibration training at 40 Hz and 50 Hz improves peak torque of the knee extensors at 60∘/s and 240∘/s, while training at 50 Hz improves endurance of the knee extensors.

Comprensión de oraciones de esfuerzo en jóvenes y adultos mayores desde una perspectiva corpórea

Actualmente se desconoce la validez de las propuestas de la cognición corpórea y su relación con el lenguaje de los adultos mayores. Para responder a esto realizamos un experimento con los factores Esfuerzo, Imaginabilidad y Contexto Lingüístico. 50 adultos mayores (M= 66.18 años, DE= 4.39, 22 mujeres y 28 hombres) y 43 jóvenes (M= 21.28 años, DE= 1.08, 36 mujeres y 7 hombres) leyeron oraciones en la pantalla de un computador, presionando la barra espaciadora para decidir luego si una palabra se hallaba o no en la frase recién leída. Los resultados muestran efectos principales para los factores Imaginabilidad (β = 0.309; p < 0.05) y Contexto (β = -0.856; p < 0.001) en los tiempos de lectura del objeto directo, dos efectos de interacción Imaginabilidad-Esfuerzo (β = -0.732; p < 0.01) e Imaginabilidad-Contexto (β = 0.611; p < 0.05) para el complemento circunstancial y un efecto interactivo Imaginabilidad-Contexto (β = 0.727; p < 0.05) para la palabra de activación. Los resultados respaldan una visión de corporeidad débil con integración interactiva de las propiedades corpóreas y simbólicas de los textos. Es necesario ampliar la investigación a otros parámetros corpóreos, edades y lenguas para contrastar estos resultados.

Low Vibrational Training as an Additional Intervention for Postural Balance, Balance Confidence and Functional Mobility in Type 2 Diabetic Patients with Lower Limb Burn Injury: A Randomized Clinical Trial

PURPOSE

Burn injury with pre-existing diabetes has poorer outcomes and complications. Balance and functional mobility are disturbed in diabetic patients with burn injury which increase the risk of total morbidity. The aim of the current study was to evaluate the impact of vibrational training as an additional intervention on postural balance, balance confidence and functional mobility in type 2 diabetic patients with lower limb burn injury.

PATIENTS AND METHODS

Thirty-eight type 2 diabetic patients of both sexes with healed lower limb burn were randomly assigned into two equal groups: the vibration group and the control group. The vibration group received whole body vibration (WBV), 3 sessions a week for 8 weeks, in addition to the selected exercise program (balance exercises and resisted exercises), while the control group only received the selected exercise program. Biodex Balance System was used to assess the dynamic balance score, the Activities-specific Balance Scale to assess balance confidence and the timed up and go test to assess the functional mobility. All measurements were obtained before and at the end of the study after 8 weeks of treatment.

RESULTS

Marked improvement in all dynamic balance indices; overall stability index, antero-posterior stability index and medio-lateral stability index, balance confidence and the functional mobility were obtained in both the vibration and the control groups (P< 0.05), whereas post-treatment comparison between groups revealed a statistically significant difference in favor of the vibration group in all measured variables.

CONCLUSION

Based on the results of the current study, it is possible to conclude that adding WBV training for an 8-week duration to a selected exercise program (balancing and resisted exercises) seems to be effective; in improving postural balance, balance confidence, as well as improving the functional mobility in type 2 diabetic patients with lower limb burn injury.

Aquatic exercise improves functional capacity, perceptual aspects, and quality of life in older adults with musculoskeletal disorders and risk of falling: A randomized controlled trial

BACKGROUND

This study aimed to determine the effects of an aquatic training program on functional capacity, perceptual aspects, and quality of life (QoL) performed by older adults with musculoskeletal disorders (MSDs) and moderate/high risk of falls.

METHODS

This randomized controlled trial included 120 older adults assigned to aquatic exercises (AG; n = 60; 70.62 ± 6.04 years) and a control group (CG; n = 60; 71.86 ± 6.95 years). The risk of falls, perceptual aspects (fall risk awareness and pain), functional capacity (lower and upper body strength, lower and upper body flexibility, functional mobility, and balance) and QoL were assessed at baseline and after the experimental protocol. The AG performed 16 weeks of aquatic exercises (twice per week, 45 min.session^-1) with lower and upper body strength, stretching, and balance exercises. Exercise intensity was controlled using the rate of perceived exertion (12-16 on the Borg scale [6-20 points]) and heart rate (progressing from 40% to 60% of the heart-rate reserve).

RESULTS

The training program improved the lower (mean difference [95% CI]: 2.7 [2.0 to 3.3]) and upper body strength (3.5 [2.6 to 4.5]), lower (4.6 [3.4 to 5.8]) and upper body flexibility (6.5 [4.3 to 8.6]), functional mobility (-2.5 [-2.9 to -1.9]), and balance (11.2 [10.6 to 11.9]); reduced pain perception (-3.2 [-3.7 to -2.8]); increased the fall risk awareness (9.5 [8.8 to 10.1]) and QoL perception (5.6 to 22.6 [4.6 to 25.1]).

CONCLUSIONS

The water-based program may be used as a preventive approach for the older adults with MSDs and at risk of falling to improve physical and usual perceptual aspects (QoL and pain) and fall risk awareness.

Effect of combined aquatic and cognitive training on quality of life, fall self-efficacy, and motor performance in aged with varying cognitive status: a proof-of-concept study

With the increasing number of aged individuals, research pertaining to their cognitive functions and physical-motor has become exponentially imperative. The purpose of the study was to investigate the effect com-bined aquatic and cognitive training on quality of life (QoL), fall self-effi-cacy and motor performance (static and dynamic balance) in aged with varying cognitive status levels. Thirty participants were assigned to a high cognitive status group (n=10), low cognitive status group (n=10), or nonintervention control group (n=10). Participants completed a 6-week motor-cognitive training regime with increasing intensity. QoL, fall self-efficacy, static balance, and dynamic balance were assessed. Preliminary results suggest proof-of-concept significant (P<0.05) im-provements were found in both the high and low cognitive status groups for static and dynamic balance and fall self-efficacy. However, QoL was only found to be significantly improved in the low cognitive status group. Aqua training along with cognitive training can effectively be used to prevent falls in the elderly and to improve their physical-motor perfor-mance. However, when attempting to improve QoL, the cognitive status of the individual should be considered.

Vibration and β-hydroxy-β-methylbutyrate treatment suppresses intramuscular fat infiltration and adipogenic differentiation in sarcopenic mice

BACKGROUND

Sarcopenia is an aging-induced deterioration of skeletal muscle mass and function. Low-magnitude high-frequency vibration (LMHFV) was shown to improve muscle functions and β-hydroxy-β-methylbutyrate (HMB) to increase muscle mass and strength. Muscle-derived stem cells (MDSCs) are progenitor cells important for muscle regeneration. We hypothesized that LMHFV and HMB could retard sarcopenia by reducing fat infiltration through inhibiting adipogenesis in MDSCs.

METHODS

Senescence-accelerated mouse P8 male mice were randomized into control (CTL), HMB, LMHFV (VIB), and combined (COM) groups. Interventions started at age of month 7 and assessed at 1, 2, and 3 months post-intervention by densitometry, histology, and functional tests. In vitro, MDSCs isolated from gastrocnemius of senescence-accelerated mouse P8 mice were characterized, randomized into CTL, VIB, HMB, and COM groups, and assessed by oil red O staining, mRNA, and protein expression.

RESULTS

At 2 months post-intervention, percentage lean mass of HMB, VIB, and COM groups were significantly higher than CTL group. Twitch, tetanic, and specific tetanic forces of COM group were higher, while specific twitch force of both VIB and COM groups were higher. Grip strength of HMB, VIB, and COM groups were higher. Histologically, both VIB and COM groups presented lower oil red O area than CTL group. Type I muscle fibre in CTL group was higher than HMB, VIB, and COM groups. MDSC were detected in situ by immunofluorescence stain with stem cell antigen-1 signals confirmed with higher β-catenin expression in the COM group. The observations were also confirmed in vitro, MDSCs in the HMB, VIB, and COM groups presented lower adipogenesis vs. the CTL group. β-Catenin mRNA and protein expressions were lower in the CTL group while their relationship was further validated through β-catenin knock-down approach.

CONCLUSIONS

Our results showed that combined LMHFV and HMB interventions enhanced muscle strength and decreased percentage fat mass and intramuscular fat infiltration as compared with either treatment alone. Additive effect of LMHFV and HMB was demonstrated in β-catenin expression than either treatment in MDSCs and altered cell fate from adipogenesis to myogenesis, leading to inhibition of intramuscular lipid accumulation. Wnt/β-catenin signalling pathway was found to be the predominant regulatory mechanism through which LMHFV and HMB combined treatment suppressed MDSCs adipogenesis.

Effects of whole-body vibration under hypoxic exposure on muscle mass and functional mobility in older adults

BACKGROUND

Ageing is accompanied by a loss of muscle mass and function, which are associated with decrease of functional capacity. Combination of WBV training with normobaric hypoxic exposure could augment the beneficial effects due to synergic effects of both treatments.

AIMS

The purpose of this study was to examine the effects of 36 sessions of the combined WBV training and normobaric hypoxic exposure on muscle mass and functional mobility in older adults.

METHODS

Nineteen elderly people were randomly assigned to a: vibration normoxic exposure group (NWBV; n = 10; 20.9% FiO₂) and vibration hypoxic exposure group (HWBV; n = 9). Participants developed 36 sessions of WBV training along 18 weeks, which included 4 bouts of 30 s (12.6 Hz in frequency and 4 mm in amplitude) with 60 s of rest between bouts, inside a hypoxic chamber for the HWBV. The "Timed Up and Go Test" evaluated functional mobility. Percentages of lean mass were obtained with dual-energy X-ray absorptiometry.

RESULTS

Neither statistically significant within group variations nor statistically significant differences between both groups were detected to any parameter.

DISCUSSION

Baseline characteristics of population, training protocol and the level of hypoxia employed could cause different adaptations on muscle mass and function.

CONCLUSIONS

The combination of WBV training and hypoxic exposure did not cause any effect on either legs lean mass or functional mobility of older adults.

Modulation of Cortical Activity by High-Frequency Whole-Body Vibration Exercise: An fNIRS Study

CONTEXT

Whole-body vibration (WBV) has shown many positive effects on the human body in rehabilitation and clinical settings in which vibration has been used to elicit muscle contractions in spastic and paretic muscles.

OBJECTIVE

The purpose of this study was to investigate whether WBV exercise (WBVe) differently modulates the cortical activity associated with motor and prefrontal function based on its frequency.

METHODS

A total of 18 healthy male adults (mean age: 25.3 [2.4] y) participated in this study and performed WBVe (Galileo Advanced plus; Novotec Medical, Pforzheim, Germany) under 3 different vibration frequency conditions (4-mm amplitude with 10-, 20-, and 27-Hz frequencies) and a control condition (0-mm amplitude with 0-Hz frequency). Each condition consisted of 2 alternating tasks (squatting and standing) every 30 seconds for 5 repetitions. All subjects performed the 4 conditions in a randomized order.

MAIN OUTCOME MEASURE

Cortical activation during WBVe was measured by relative changes in oxygenated hemoglobin concentration over the primary motor cortex, premotor cortex, supplementary motor area, and prefrontal and somatosensory cortices using functional near-infrared spectroscopy.

RESULTS

Oxygenated hemoglobin concentration was higher during the 27-Hz vibration condition than the control and 10-Hz vibration conditions. Specifically, these changes were pronounced in the bilateral primary motor cortex (P < .05) and right prefrontal cortex (P < .05). In contrast, no significant changes in oxygenated hemoglobin concentration were observed in any of the cortical areas during the 10-Hz vibration condition compared with the control condition.

CONCLUSION

This study provides evidence that the motor network and prefrontal cortical areas of healthy adult males can be activated by 27-Hz WBVe. However, WBVe at lower frequencies did not induce significant changes in cortical activation.

Acute and Cumulative Effects With Whole-Body Vibration Exercises Using 2 Biomechanical Conditions on the Flexibility and Rating of Perceived Exertion in Individuals With Metabolic Syndrome: A Randomized Clinical Trial Pilot Study

This study evaluated the effects of 6 weeks of whole-body vibration (WBV) exercise on flexibility and the rating of perceived exertion (RPE) in metabolic syndrome (MetS) individuals using 2 biomechanical conditions (fixed frequency [FF] and variable frequency [VF]). Nineteen MetS individuals were randomly allocated in FF-WBV (n = 9, 7 women and 2 men) and VF-WBV (n = 10, 8 women and 2 men) groups. Anterior trunk flexion (ATF) and RPE were determined before and after each session. The acute cumulative exposure effects were analyzed. The FF-WBV group was exposed to 5 Hz on a side alternating vibrating platform (SAVP), exposed to 10 and 50 seconds with the SAVP turned off. The VF-WBV group individuals were intermittently exposed (1 minute WBV exercise/1 minute rest) to 5 to 16 Hz, increased by 1 Hz per session and the peak-to-peak displacement (PPD) were 2.5, 5.0, and 7.5 mm. Regarding to ATF, significant improvements (P < .05) were observed in the in the acute (VF group) and cumulative intervention (FF and VF-WBV groups). The RPE significantly (P < .05) improved only in VF-WBV (cumulative intervention). In conclusion, WBV exercise improved the flexibility and decreased the RPE in MetS individuals. These findings suggest that WBV exercise can be incorporated into physical activities for MetS individuals.

Motor imagery training improves balance and mobility outcomes in older adults: a systematic review

QUESTION

Does motor imagery training improve measures of balance, mobility and falls in older adults without a neurological condition?

DESIGN

Systematic review and meta-analysis of randomised controlled trials.

PARTICIPANTS

Adults aged at least 60 years and without a neurological condition.

INTERVENTION

Three or more sessions of motor imagery training.

OUTCOME MEASURES

The primary outcomes were balance measures (such as single leg stance and Berg Balance scale) and mobility measures (such as gait speed and the Timed Up and Go test). Falls were a secondary outcome measure. Risk of bias was evaluated using the PEDro Scale, and overall quality of evidence was assessed using the Grades of Research, Assessment, Development and Evaluation (GRADE) approach.

RESULTS

Twelve trials including 356 participants were included in the systematic review and 10 trials (316 participants) were included in the meta-analyses. All trials included either apparently healthy participants or older adults after orthopaedic surgery. There was evidence that motor imagery training can significantly improve balance (SMD 1.03, 95% CI 0.25 to 1.82), gait speed (MD 0.13 m/s, 95% CI 0.04 to 0.22) and Timed Up and Go (MD 1.64 seconds, 95% CI 0.79 to 2.49) in older adults; however, the quality of evidence was very low to low. No data regarding falls were identified.

CONCLUSION

Motor imagery training improves balance and mobility in older adults who do not have a neurological condition. These results suggest that motor imagery training could be an adjunct to standard physiotherapy care in older adults, although it is unclear whether or not the effects are clinically worthwhile.

TRIAL REGISTRATION

PROSPERO CRD42017069954.

Effects of Whole-Body Vibration Training Combined With Cyclic Hypoxia on Bone Mineral Density in Elderly People

Prevention and treatment of osteoporosis are an issue of great concern in public health so that the increase/maintenance of whole-body bone mineral density (BMD) is clinically relevant and could reduce the financial burden. Whole-body vibration (WBV) has been recently proposed as a potential alternative to bone stimulation, which combined with therapies, could provide a new treatment for osteoporosis prevention. In this sense, moderate cyclic hypoxia protocols may help to restrain osteoclastic activity and/or stimulate osteoblastic activity, enhance the effects of whole-body vibration alone. So, the present study investigated the effects of cyclic hypoxic exposure combined with WBV training on BMD of the elderly. Healthy elderly persons (n = 30) were randomly assigned to a (1) Hypoxia-Whole Body Vibration group (HWBV; n = 10), (2) Normoxic-Whole Body Vibration group (NWBV; n = 10) or (3) Control group (CON; n = 10). During 18 weeks, HWBV performed WBV treatment under normobaric hypoxic conditions (16.1% FiO₂). A vibration session included 4 bouts of 30 s (12.6 Hz–4 mm) with 1 min rest between bouts. NWBV performed the same vibration treatment as HWBV but under normoxic conditions. Whole-body and proximal femur BMD (g⋅cm⁻²) were measured using dual-energy X-ray absorptiometry. Two-way ANOVA indicated a borderline significant (p = 0.07) time x group interaction for total BMD; post hoc analysis revealed a slight but significant (p = 0.021) increase of BMD after treatment in the HWBV group. In conclusion, 18-week WBV training with hypoxic stimuli has shown positive effects for the participants of the current study. As changes did not differ significantly between groups, future large-scale studies will be necessary to confirm these findings.

Long-Term Effects of Whole-Body Vibration on Human Gait: A Systematic Review and Meta-Analysis

Background: Whole-body vibration is commonly used in physical medicine and neuro-rehabilitation as a clinical prevention and rehabilitation tool. The goal of this systematic review is to assess the long-term effects of whole-body vibration training on gait in different populations of patients.

Methods: We conducted a literature search in PubMed, Science Direct, Springer, Sage and in study references for articles published prior to 7 December 2018. We used the keywords “vibration,” “gait” and “walk” in combination with their Medical Subject Headings (MeSH) terms. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology was used. Only randomized controlled trials (RCT) published in English peer-reviewed journals were included. All patient categories were selected. The duration of Whole-Body Vibration (WBV) training had to be at least 4 weeks. The outcomes accepted could be clinical or biomechanical analysis. The selection procedure was conducted by two rehabilitation experts and disagreements were resolved by a third expert. Descriptive data regarding subjects, interventions, types of vibration, training parameters and main results on gait variables were collected and summarized in a descriptive table. The quality of selected studies was assessed using the PEDro scale. Statistical analysis was conducted to evaluate intergroup differences and changes after the WBV intervention compared to the pre-intervention status. The level of evidence was determined based on the results of meta-analysis (effect size), statistical heterogeneity (I²) and methodological quality (PEDro scale).

Results: A total of 859 studies were initially identified through databases with 46 articles meeting all of the inclusion criteria and thus selected for qualitative assessment. Twenty-five studies were included in meta-analysis for quantitative synthesis. In elderly subjects, small but significant improvements in the TUG test (SMD = −0.18; 95% CI: −0.32, −0.04) and the 10MWT (SMD = −0.28; 95% CI: −0.56, −0.01) were found in the WBV groups with a strong level of evidence (I² = 7%, p = 0.38 and I² = 22%, p = 0.28, respectively; PEDro scores ≥5/10). However, WBV failed to improve the 6MWT (SMD = 0.37; 95% CI: −0.03, 0.78) and the Tinetti gait scores (SMD = 0.04; 95% CI: −0.23, 0.31) in older adults. In stroke patients, significant improvement in the 6MWT (SMD = 0.33; 95% CI: 0.06, 0.59) was found after WBV interventions, with a strong level of evidence (I² = 0%, p = 0.58; PEDro score ≥5/10). On the other hand, there was no significant change in the TUG test despite a tendency toward improvement (SMD = −0.29; 95% CI: −0.60, 0.01). Results were inconsistent in COPD patients (I² = 66%, p = 0.03), leading to a conflicting level of evidence despite a significant improvement with a large effect size (SMD = 0.92; 95% CI: 0.32, 1.51) after WBV treatment. Similarly, the heterogeneous results in the TUG test (I² = 97%, p < 0.00001) in patients with knee osteoarthrosis make it impossible to draw a conclusion. Still, adding WBV treatment was effective in significantly improving the 6 MWT (SMD = 1.28; 95% CI: 0.57, 1.99), with a strong level of evidence (I² = 64%, p = 0.06; PEDro score ≥5/10). As in stroke, WBV failed to improve the results of the TUG test in multiple sclerosis patients (SMD = −0.11; 95% CI: −0.64, 0.43). Other outcomes presented moderate or even limited levels of evidence due to the lack of data in some studies or because only one RCT was identified in the review.

Conclusions: WBV training can be effective for improving balance and gait speed in the elderly. The intervention is also effective in improving walking performance following stroke and in patients with knee osteoarthrosis. However, no effect was found on gait quality in the elderly or on balance in stroke and multiple sclerosis patients. The results are too heterogenous in COPD to conclude on the effect of the treatment. The results must be taken with caution due to the lack of data in some studies and the methodological heterogeneity in the interventions. Further research is needed to explore the possibility of establishing a standardized protocol targeting gait ability in a wide range of populations.

Evaluation of 18-Week Whole-Body Vibration Training in Normobaric Hypoxia on Lower Extremity Muscle Strength in an Elderly Population

Therapeutic benefits of hypoxic training have been suggested for clinical populations, such as elderly who could suffer loss of lower limb muscle strength and higher risk of falling. This study investigated the effects of 18 weeks of whole-body vibration (WBV) training in normobaric hypoxia on the strength parameters of an elderly population. Thirty-one healthy elderly participants were randomly assigned to a hypoxic whole-body vibration group (HWBV; n = 10), normoxic whole-body vibration group (NWBV; n = 11), or control group (n = 10). The experimental groups received the same vibration treatment in a hypoxia chamber (HWBV: 16.1% fraction of inspired oxygen [FiO₂]; NWBV: 21.0% FiO₂). Isokinetic leg muscle strength was evaluated using a Biodex System-3 isokinetic dynamometer. Body composition was obtained with dual-energy X-ray absorptiometry. There were no significant differences between groups in either strength or body composition parameters. The NWBV group showed statistically significant improvements in the maximal strength of knee extensors, with a small effect size (p = 0.004; d = 0.54). No significant differences were found in any variable of the HWBV group. The combination of WBV training and exposure to normobaric cyclic hypoxia carried out in the present study did not have an effect on strength parameters in healthy elderly subjects.

Effects of Whole-Body Vibration on Lumbar-Abdominal Muscles Activation in Healthy Young Adults: A Pilot Study

BACKGROUND This study investigated how whole-body vibration (WBV), exercise, and their interactions influence core muscle activity in healthy young adults. MATERIAL AND METHODS Twenty-three healthy young adults (8 males and 15 females; age: 21.87±2.33 years) participated in the study. The activities of muscle multifidi (MM), rectus abdominis muscle (RM), erector spinae (ES), abdominis obliquus externus (AOE), and abdominis obliquus internus (AOI) were measured through surface electromyography (sEMG) while participants were performing 4 different exercise forms under 3 WBV conditions (condition 1: 5 Hz, 2 mm; condition 2: 10 Hz, 2 mm; and condition 3: 15 Hz, 2 mm) and a no-WBV condition in single experimental sessions. RESULTS The WBV frequency of 15 Hz is the best vibration stimulation for core muscles in all of the exercises (P<0.05). Single bridge is a better exercise for RM and AOE (P<0.05) compared with other exercises, and crunches is the best exercise for MM, AOI, and ES (P<0.05). Significant interaction effect was observed in different frequencies and exercises (P>0.05) except for AOI (F=0.990, P=0.378). CONCLUSIONS High vibration frequencies can lead to enhanced exercise benefits within an appropriate frequency range, and different exercises have diverse effects on various muscles. Single bridge and crunches are appropriate exercise forms for lumbar-abdominal muscles.

Transmission of Acceleration From a Synchronous Vibration Exercise Platform to the Head During Dynamic Squats

Many research studies have evaluated the effects of whole-body vibration exercise on muscular strength, standing balance, and bone density, but relatively few reports have evaluated safety issues for vibration exercises. Knee flexion reduces acceleration transmission to the head during static exercise. However, few studies have evaluated dynamic exercises. The purpose of this investigation was to evaluate the transmission of acceleration to the head during dynamic squats. Twelve participants performed dynamic squats (0°-40° of knee flexion) on a synchronous vertical whole-body vibration platform. Platform frequencies from 20 to 50 Hz were tested at a peak-to-peak nominal displacement setting of 1 mm. Transmissibilities from the platform to head varied depending on platform frequency and knee flexion angle. We observed amplification during 20 and 25 Hz platform vibration when knee flexion was <20°. Vibration from exercise platforms can be amplified as it is transmitted through the body to the head during dynamic squats. Similarly, this vibration energy contributes to observed injuries such as retinal detachment. It is recommended that knee flexion angles of at least 20° and vibration frequencies above 30 Hz are used when performing dynamic squat exercises with whole-body vibration.