Effect of whole body vibration training on quadriceps muscle strength in individuals with knee osteoarthritis: a systematic review and meta-analysis

The impact of digital healthcare systems on pain and body function in patients with knee joint pain: a systematic review and meta-analysis

The digital healthcare (DH) system has recently emerged as an advanced rehabilitation approach that promotes rehabilitation training based on virtual reality (VR) and augmented reality (AR). The purpose of this meta-analysis study is to review and assess the impact of DH systems on pain and physical function among patients diagnosed with knee joint pain. Between January 2003 and September 2023, studies that met the listed inclusion criteria were gathered from Scopus, PubMed, Web of Science, and EBSCO databases. The analysis of standardized mean difference (SMD) was carried out with 95% confidence interval (95% CI) (PROSPERO registration number: CRD42023462538). Eight research papers were selected, which collectively involved 194 males and 279 females. The meta-analysis outcomes revealed that DH intervention significantly improved balance (SMD, 0.41 [0.12, 0.69], p < 0.05) and pain level (SMD, - 1.10 [- 2.02, - 0.18], p < 0.05). The subgroup analysis of the pain level showed varied outcomes for the TKA (SMD, - 0.22 [- 0.49, 0.04], p = 0.10) or OA patients (SMD, - 2.80 [- 3.83, - 1.78], p < 0.05) Next, this study found no significant effect of DH intervention on knee joint range of motion (ROM) (SMD, 0.00 [- 0.76, 0.76], p = 1.00) and walking velocity (SMD, 0.04 [- 0.22, 0.29], p = 0.77) in patients with knee joint pain. The meta-analysis review conducted in this study revealed that DH intervention may potentially improve balance among the patients with knee joint pain. It may also alleviate the pain level particularly among OA patients.

Impacts of whole-body vibration on denervated skeletal-muscle atrophy in rats

Whole-body vibration has been considered as a countermeasure against muscle atrophy. However, its effects on muscle atrophy are poorly understood. We evaluated the effects of whole-body vibration on denervated skeletal muscle atrophy. Whole-body vibration was performed on rats from Day 15 to 28 after denervation injury. Motor performance was evaluated using an inclined-plane test. Compound muscle action potentials of the tibial nerve were examined. Muscle wet weight and muscle fiber cross-sectional area were measured. Myosin heavy chain isoforms were analyzed in both muscle homogenates and single myofibers. Whole-body vibration resulted in a significantly decreased inclination angle and muscle weight, but not muscle fiber cross-sectional area of fast-twitch gastrocnemius compared to denervation only. In denervated gastrocnemius, a fast-to-slow shift was observed in myosin heavy chain isoform composition following whole-body vibration. There were no significant changes in muscle weight, muscle fiber cross-sectional area, and myosin heavy chain isoform composition in denervated slow-twitch soleus. These results imply that whole-body vibration does not promote recovery of denervation-induced muscle atrophy.

Low-frequency whole-body vibration can enhance cartilage degradation with slight changes in subchondral bone in mice with knee osteoarthritis and does not have any morphologic effect on normal joints

PURPOSES

To evaluate the effects of low frequency whole-body vibration (WBV) on degeneration of articular cartilage and subchondral bone in mice with destabilization of the medial meniscus (DMM)induced osteoarthritis(OA) and mice with normal knee.

METHODS

Ten-week-old C57BL/6J male mice received DMM on right knees, while the left knees performed sham operation. There were six groups: DMM, SHAM DMM, DMM+WBV,SHAM DMM+WBV, DMM+ NON-WBV and SHAM DMM+NON-WBV. After four weeks, the knees were harvested from the DMM and SHAM DMM group. The remaining groups were treated with WBV (10 Hz) or NON-WBV. Four weeks later, the knees were harvested. Genes, containing Aggrecan(Acan) and CollagenⅡ(Col2a1), Matrix Metalloproteinases 3 and 13(MMP3,13), TNFα and IL6, were measured and staining was also performed. OA was graded with OARSI scores, and tibial plateaubone volume to tissue volume ratio(BV/TV), bone surface area to bone volume ratio (BS/BV), trabecular number(Tb.N) and trabecular thickness separation(TS) between groups were analyzed.

RESULTS

Increased OARSI scores and cartilage degradation were observed after WBV. BV/TV, Tb.N and TS were not significant between the groups. Significant reductions were observed in MMP3, MMP13, Col2a1, Acan, TNFα and IL6 in the DMM+WBV compared to SHAM DMM+WBV group. BV/TV, BS/BV, Tb.N, TS and OARSI scores were not significantly changed in the left knees. IL6 expression in the SHAM DMM+WBV group was significantly increased compared with the SHAM DMM+ NON-WBV group, while Col2a1, Acan and MMP13 expression decreased.

CONCLUSION

WBV accelerated cartilage degeneration and caused slight changes in subchondral bone in a DMM-induced OA model. WBV had no morphologic effect on normal joints.

The Effect of a Virtual Reality-Mediated Gamified Rehabilitation Program on Pain, Disability, Function, and Balance in Knee Osteoarthritis: A Prospective Randomized Controlled Study

Background: This prospective randomized controlled study is the first study that evaluates the disease-specific gamification through virtual reality (VR) glasses on pain, disability, functionality, and balance in knee osteoarthritis (OA). Materials and Methods: The demographic data of the patients were recorded. A total of 73 patients were divided into two groups (35 in experimental group and 38 in control group). All patients were evaluated with pain (visual analog scale [VAS]), functionality (Lysholm functional knee score [LFKS], 6 minutes walking test [6MWT]), disability (Western Ontario and McMaster Universities Arthritis Index [WOMAC]), and balance (Berg Balance Scale [BBS]) before treatment, after treatment (3th weeks), and 4 weeks after treatment (7th weeks). In the experimental group, plus the conservative treatment, a total of 15 sessions of a disease-specific gamification through VR glasses were applied. Results: VAS and WOMAC scores of the experimental group were lower at the 3th and 7th weeks than those of the control group (P = 0.005, P = 0.000), (P = 0.000). LFKS of the experimental group was higher at the 3th and 7th weeks than that of the control group (P = 0.005, P = 0.013). No difference was found between the groups in terms of 6MWTs (P > 0.05). BBS score of the experimental group was higher in the 7th week than that of the control group (P = 0.021). Conclusion: In knee OA, the disease-specific gamification through VR glasses added to the conservative treatment has a positive effect on pain, functionality, and balance. Side effects such as mild nausea, headache that did not last long, require additional treatment. In light of this, disease-specific gamification through VR glasses is effective and safe in knee OA, more studies that reveal the long-term effect on structural healing must be planned.

Effect of equipping an unloader knee orthosis with vibrators on pain, function, stiffness, and knee adduction moment in people with knee osteoarthritis: A pilot randomized trial

BACKGROUND

Wearing unloader knee orthoses for the long term may have a side effect on knee adduction moment (KAM).

RESEARCH QUESTION

This study sought to determine whether equipping an unloader knee orthosis with vibrators improves its effectiveness in pain, stiffness, function, and reducing the KAM.

METHODS

The authors performed a clinical evaluation with the Western Ontario and McMaster Universities (WOMAC) questionnaire and instrumented gait analyses on 14 participants with medial compartment knee osteoarthritis in two testing sessions: before wearing the orthosis and after 6 weeks of use.

RESULTS AND SIGNIFICANCE

Wearing both orthoses for 6 weeks significantly improved (p < 0.05) pain, stiffness, and function compared to the baseline assessment. There was a significantly greater reduction in the first peak KAM (p = 0.016) and KAM impulse (p = 0.008) in the vibratory unloader knee orthosis than in the conventional knee orthosis in the second session. Equipping the unloader knee orthosis with vibrators can improve its effectiveness in reducing the KAM and can prevent the side effects of its use. Furthermore, equipping the unloader knee orthosis with the vibrators did not interfere with its effectiveness on pain, stiffness, and function.

Effect of whole-body vibration on neuromuscular activation and explosive power of lower limb: A systematic review and meta-analysis

OBJECTIVE

The review aimed to investigate the effects of whole-body vibration (WBV) on neuromuscular activation and explosive power.

METHODS

Keywords related to whole-body vibration, neuromuscular activation and explosive power were used to search four databases (PubMed, Web of Science, Google Scholar and EBSCO-MEDLINE) for relevant studies published between January 2000 and August 2021. The methodology of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses was used. The eligibility criteria for the meta-analysis were based on PICOST principles. Methodological assessment used the Cochrane scale. Heterogeneity and publication bias were assessed by I2 index and funnel plots, respectively. The WBV training cycle is a random effect model. Publication bias was also assessed based on funnel plots. This study was registered in PROSPERO (CRD42021279439).

RESULTS

A total of 156 participants data in 18 studies met the criteria and were included in the meta-analysis for quantitative synthesis. Results of the meta-analysis showed significant improvements in lower limb neuromuscular activation immediately after WBV compared with the baseline (SMD = 0.51; 95% CI: 0.26, 0.76; p<0.001), and no significant heterogeneity was observed (I2 = 38%, p = 0.07). In addition, the highest increase in lower limb explosive power was observed (SMD = 0.32; 95% CI: 0.11, 0.52; p = 0.002), and no significant heterogeneity (I2 = 0%, p = 0.80) was noted.

CONCLUSIONS

WBV training could improve neuromuscular activation and explosive power of the lower limb. However, due to different vibration conditions, further research should be conducted to determine standardized protocols targeting performance improvement in athletes and healthy personnel experienced in training.

Whole-body vibration provides additional benefits to patients with patellofemoral pain: A protocol for systematic review and meta analysis of randomized controlled trials

BACKGROUND

The efficacy of the whole-body vibration (WBV) training for patients with patellofemoral pain (PFP) remains controversial. For this reason, we applied a meta-analysis of randomized controlled trials (RCTs) to evaluate the efficacy of WBV training in patients with PFP.

METHODS

Relevant studies found within PubMed, EMBASE, the Cochrane Library and Web of Science were examined from January 1, 1990 to December 30, 2021. Two evaluators independently screened the literatures, extracted relevant data and assessed the methodological quality of respective studies. Meta-analysis was conducted using RevMan 5.4 software.

RESULTS

A total of 5 RCTs with 174 patients were included. When comparing with exercise alone, WBV training in combination with exercise provided better reduction of pain assessed by visual analogue scale score (P = .04). There were no differences regarding changes of Kujala patellofemoral score, the physical component summary score for physical health, and the mental component summary score for mental health (P = .08, 0.76, 0.65 respectively) between patients with WBV training and those without WBV training.

CONCLUSIONS

Compared to the sole performance of exercise, WBV training in combination with exercise showed better pain reduction, but no superior improvement in function and on quality of life.

Whole Body Vibration: A Valid Alternative Strategy to Exercise?

Several studies agree that mechanical vibration can induce physiological changes at different levels, improving neuromuscular function through postural control strategies, muscle tuning mechanisms and tonic vibration reflexes. Whole-body vibration has also been reported to increase bone mineral density and muscle mass and strength, as well as to relieve pain and modulate proprioceptive function in patients with osteoarthritis or lower back pain. Furthermore, vibratory training was found to be an effective strategy for improving the physical performance of healthy athletes in terms of muscle strength, agility, flexibility, and vertical jump height. Notably, several benefits have also been observed at the brain level, proving to be an important factor in protecting and/or preventing the development of age-related cognitive disorders. Although research in this field is still debated, certain molecular mechanisms responsible for the response to whole-body vibration also appear to be involved in physiological adaptations to exercise, suggesting the possibility of using it as an alternative or reinforcing strategy to canonical training. Understanding these mechanisms is crucial for the development of whole body vibration protocols appropriately designed based on individual needs to optimize these effects. Therefore, we performed a narrative review of the literature, consulting the bibliographic databases MEDLINE and Google Scholar, to i) summarize the most recent scientific evidence on the effects of whole-body vibration and the molecular mechanisms proposed so far to provide a useful state of the art and ii) assess the potential of whole-body vibration as a form of passive training in place of or in association with exercise.

Mechanical-based therapies may reduce pain and disability in some patients with knee osteoarthritis: A systematic review with meta-analysis

BACKGROUND

Mechanical-based therapies are not yet recommended to manage osteoarthritis (OA). This systematic review and meta-analysis aim to assess the effects of passive mechanical-based therapies (isolated or combined with other therapies) on patients with knee OA compared to placebo, other isolated or combined interventions.

METHODS

Pubmed, Cochrane, Web of Science and EMBASE were searched up to December 2020. We included randomized and non-randomized trials using therapeutic ultrasound, phonophoresis, extracorporeal shockwave therapy (ESWT) and vibration (single or combined with other therapies) compared to placebo, and/or other physical therapies groups. Biochemical, patient-reported, physical and imaging outcome measures were retrieved. We judged risk of bias using the RoB2 tool for randomized studies, the ROBINS-I tool for non-randomized studies, and the GRADE to interpret certainty of results.

RESULTS

We included 77 clinical studies. Ultrasound and ESWT statistically improved pain and disability comparing to placebo (combined or not with other therapies), and when added to other therapies versus other therapies alone. Ultrasound was statistically inferior to phonophoresis (combined or not with other therapies) in reducing pain and disability for specific therapeutic gels and/or combined therapies. Vibration plus exercise statistically improved pain relief and function versus exercise alone. All meta-analyses showed very-low certainty of evidence, with 15 of 42 (38%) pooled comparisons being statistically significant (weak to large effect).

CONCLUSIONS

Despite the inconsistent evidence with very-low certainty, the potential benefits of passive mechanical-based therapies should not be disregard and cautiously recommended that clinicians might use them in some patients with knee OA.

The Application of Whole-Body Vibration Training in Knee Osteoarthritis

With the gradual increase of the aging population in Chinese society, the incidence of knee osteoarthritis showed an increasing trend. However, there are very few practical solutions for it. As a novel neuromuscular training technique, whole-body vibration training has become a candidate for treating knee osteoarthritis. In this review, we firstly elaborated on the mode of action and influence factors of the whole-body vibration training. Next, we summarized its effects in knee osteoarthritis, including improving knee function and some uncertain muscle function and proprioception effects. Next, we also summarized its possible mechanisms, including improving bone microstructure, delaying articular cartilage degeneration, modulating inflammatory cells and inflammatory factors. Then, we summarized the clinical effectiveness of whole-body vibration training by analyzing some clinical randomized controlled trials. Finally, based on the above summary, we analyzed and listed the limitations of whole-body vibration training in treating knee osteoarthritis and found the shortcomings in the existing studies. This review provides ideas for the future application of whole-body vibration training in the treatment of knee osteoarthritis.

Effect of Whole-Body Vibration Training on Muscle Activation for Individuals with Knee Osteoarthritis

Whole-body vibration (WBV) training may improve the strength of lower extremity muscles in patients with knee osteoarthritis (KOA), but the inconsistency in vibration parameters leads to differences in findings. This cross-sectional study is aimed at observing the effects of different vibration frequencies and knee flexion angles on the activation of lower extremity muscles in patients with KOA. Enrolled participants received WBV training at 0, 30, and 60° knee flexion angles with vibration frequencies of 0, 5, 10, and 20 Hz. Activation rates for vastus medialis, vastus lateralis, rectus femoris, biceps femoris, and semitendinosus in different combinations were collected through surface electromyography. The effects of frequency and angle on muscle activation rate were quantified by repeated measures ANOVA. Individual and synergistic effects of frequency and angle were also analysed. Twenty-six participants with KOA were included. Muscle activation increased with the vibration frequency in 0–20 Hz range and with knee flexion angle in 0–60° range. WBV training at 20 Hz was the most effective for knee muscle activation, and static squatting at 60° was the most suitable for WBV training. Therefore, WBV training can increase the activation rate of knee flexor and extensor muscles in patients with KOA, and the most efficient combination was 20 Hz vibration frequency and 60° knee flexion. When applying WBV to patients with KOA, individual differences and rehabilitation purposes should be considered in selecting vibration parameters and knee angle to effectively increase neuromuscular activity.

Comparison of whole-body vibration training and quadriceps strength training on physical function and neuromuscular function of individuals with knee osteoarthritis: A randomised clinical trial

Background

Knee osteoarthritis (KOA) is one of the leading causes of global disability, which causes knee pain, stiffness and swelling. Impaired neuromuscular function may cause joint instability, alignment changes and knee stress, which leads to the progression of KOA. Whole-body vibration (WBV) training is considered to improve pain and functional mobility effectively. However, few studies have investigated the therapeutic effect of WBV on neuromuscular function in KOA.

Material and methods

A single-blinded, randomised, controlled trial was performed on 81 participants diagnosed with KOA. The participants were randomised into three groups: (1) WBV group, in which participants performed strength training (ST) with vibration exposure for 8 weeks; (2) ST group, in which participants performed ST without vibration for 8 weeks; and (3) health education (HE) group, in which participants received a HE for 8 weeks. The visual analogue scale for knee pain, isokinetic muscle strength test, proprioception test, Timed Up and Go test (TUG) and 6-min Walk Distance test (6MWD) were performed before and after the interventions.

Results

No significant difference was found on pain, proprioception, TUG and 6MWD. A significant interaction effect was found in isokinetic muscle strength between groups. Further analysis showed that compared with the HE group, the WBV group exhibited significantly greater improvement in isokinetic muscle strength (peak torque [PT] of extensors, p < 0.01, 95% CI = 0.11-0.33 Nm/kg; PT of flexors, p = 0.01, 95% CI = 0.02-0.19 Nm/kg; peak work [PW] of extensors, p < 0.01, 95% CI = 0.12-0.75 W/kg). In addition, compared with the ST group, the muscle strength of the WBV group (PT of extensors, p < 0.01, 95% CI = 0.10-0.32 Nm/kg; PW of extensors, p < 0.01, 95% CI = 0.09-0.71 W/kg) improved significantly.

Conclusion

Our findings suggested that adding WBV training to ST might benefit muscle strength around the knee joint in patients with KOA.

Effects of whole body vibration with exercise therapy versus exercise therapy alone on flexibility, vertical jump height, agility and pain in athletes with patellofemoral pain: a randomized clinical trial

Background

Patellofemoral pain (PFP) is the most prevalent orthopedic problem in active young adults. Due to its multifactorial etiology, a variety of therapeutic measures have been adopted to treat PFP, including exercise therapy, electrotherapy, and manual therapy. It has also been suggested that whole body vibration (WBV) can improve neuromuscular function in persons with knee problems. The aim of the present study was to evaluate the effects of adding WBV to routine exercise programs on flexibility, vertical jump height, agility and pain in athletes with PFP.

Methods

Twenty-four male athletes with PFP were randomized into two groups of WBV + exercise (n = 12) or exercise only (n = 12). Participants received their interventions during 4 consecutive weeks (12 sessions). Pain intensity, flexibility and agility were assessed respectively as score on a numerical rating scale, the sit-and-reach test, and a modified T-test, and vertical jump height was measured to the nearest centimeter. The tests were done before and after the interventions, and the results were compared between the two groups. Independent t-tests and paired t-tests were used for between- and within-group comparisons, respectively.

Results

After the interventions, all variables for vertical jump height, flexibility, agility and pain intensity improved significantly in both groups (p < 0.05). The flexibility test showed significantly greater improvement in the WBV + exercise group (p<0.001), whereas for vertical jump height, agility and pain intensity, there were no statistically significant differences between groups (p>0.05).

Conclusions

The present findings showed that exercise therapy with and without WBV can significantly decrease pain and increase agility, vertical jump height and flexibility in athletes with PFP. Adding WBV to routine exercise therapy, however, can augment the effects of the latter on flexibility.

Trial registration

IRCT, IRCT20090831002391N39. Registered 7 February 2018, https://en.irct.ir/search/result?query=IRCT20090831002391N39.

Effects of Whole-Body Vibration Exercises on Parameters Related to the Sleep Quality in Metabolic Syndrome Individuals: A Clinical Trial Study

Metabolic syndrome (MetS) is an undesirable clinical condition with physiological, biochemical, clinical, and metabolic factors that contribute to increased cardiovascular risks (CR). A poor sleep quality might be found in obese and MetS individuals. Whole-body vibration (WBV) exercise has been used on the management of MetS individuals. This clinical trial investigated the effect of WBV exercise on parameters related to the sleep quality in MetS individuals. After randomization, nine individuals (seven women and two men) were exposed to a fixed frequency (FF) and ten individuals (eight women and two men) were exposed to a variable frequency (VF). Both groups performed the protocol twice a week, for 6 weeks. All of the evaluations were performed before the first and after the last sessions. Anthropometric and cardiovascular parameters were measured before and after the 6-week intervention. Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), and Berlin Questionnaire were also used to evaluate the quality of the sleep. A significant (p ≤ 0.05) reduction of the waist circumference in the VFG and an increase of the heart rate were found in the FFG and VFG group. The score of the PSQI of the both groups decreased significantly (p = 0.01). The score of the ESS decreased (p = 0.04) only in the VF group. The scores of the Berlin Questionnaire were not altered in both groups. In conclusion, WBV intervention was capable in interfering with physiological mechanisms with effects on the WC and HR, leading to the improvement of the quality of sleep in MetS individuals. WBV exercise might be an important clinical intervention to the management of some factors associated with poor quality of sleep (FFG and VFG) and in the daytime sleepiness in MetS individuals with variable frequencies (5–16 Hz) (VFG).

Early Post-Operative Intervention of Whole-Body Vibration in Patients After Total Knee Arthroplasty: A Pilot Study

(1) Background: Knee osteoarthritis causes pain, weakness, muscle atrophy, and disability. The application of whole-body vibration in patients with knee osteoarthritis can improve strength, balance, and functional activities. The purpose of the study is to evaluate the effects of early whole-body vibration intervention in patients after total knee arthroplasty. (2) Method: A single-blinded randomized control trial. Fifty-two patients with knee osteoarthritis post total knee replacement from a medical center in southern Taiwan were randomly assigned to either a whole-body vibration group or control group. Main outcome measures included pain severity, leg circumference, knee range of motion, knee extensor strength, a five-times sit to stand test, and a timed up and go test. (3) Results: Immediately post treatment, the patients in the vibration group showed a significant increase in knee extensor strength and improvement in calf swelling compared to the control group. A trend toward decrease in pain severity and improvement in functional performance were observed in both groups without a significant difference between the groups. There was no significant difference in knee range of motion (ROM) and functional performance between the groups. (4) Conclusions: The whole-body vibration intervention in patients early post total knee arthroplasty showed significant immediate effect in increasing knee extensor strength and decreasing calf swelling.

Effects of Mechanical Vibration in Neuromuscular Junctions and Fiber Type of the Soleus Muscle of Oophorectomized Wistar Rats

Objective  To evaluate the neuromuscular junctions (NMJs) and the type of muscle fibers of the soleus muscle of oophorectomized Wistar rats submitted to a mechanical vibration protocol. Methods  A total of 36 randomized rats were used in the pseudo-oophorectomy without and with treatment and oophorectomy without and with treatment groups. The treatment was performed with a vibratory platform, frequency of 60 Hz and duration of 10 minutes, 3 times a week, for 4 weeks. At the end of the intervention period, the animals were euthanized and the soleus muscles were collected and processed for analysis of the NMJs and fiber type. The data were analyzed for normality by the Shapiro-Wilk test and analysis of the 3-way variance using the post-hoc Tukey test, when necessary, and a significance level of 5% was adopted. Results  In the analysis of the NMJs, the oophorectomy group presented a smaller area than the pseudo-oophorectomy group, but the oophorectomy with treatment group was equal to the pseudo-oophorectomy with treatment group. For the larger diameter of the joints, the oophorectomy group was also different from the others; however, the oophorectomy and treatment animals were larger than those of the pseudo-oophorectomy and treatment group. There was no distinction of the types of fibers, with the muscle presenting fibers of the oxidative type. Conclusion  Hormonal deprivation reduced the area and diameter of the NMJs, with reversion of this process in the groups that underwent vibratory platform treatment for 4 weeks, and both surgery and treatment did not influence the type of soleus muscle fiber, composed of oxidative fibers.

Comparison of a Vibration Roller and a Nonvibration Roller Intervention on Knee Range of Motion and Pressure Pain Threshold: A Randomized Controlled Trial

BACKGROUND

Roller massage (RM) has become a common intervention among health and fitness professionals. Recently, manufacturers have merged the science of vibration therapy and RM with the development of vibration rollers. Of interest, is the therapeutic effects of such RM devices.

PURPOSE

The purpose of this study was to compare the effects of a vibration roller and nonvibration roller intervention on prone knee-flexion passive range of motion (ROM) and pressure pain threshold (PPT) of the quadriceps musculature.

METHODS

Forty-five recreationally active adults were randomly allocated to one of 3 groups: vibration roller, nonvibration roller, and control. Each roller intervention lasted a total of 2 minutes. The control group did not roll. Dependent variables included prone knee-flexion ROM and PPT measures. Statistical analysis included parametric and nonparametric tests to measure changes among groups.

RESULTS

The vibration roller demonstrated the greatest increase in PPT (180 kPa, P < .001), followed by the nonvibration roller (112 kPa, P < .001) and control (61 kPa, P < .001). For knee flexion ROM, the vibration roller demonstrated the greatest increase in ROM (7°, P < .001), followed by the nonvibration roller (5°, P < .001) and control (2°, P < .001). Between groups, there was a significant difference in PPT between the vibration and nonvibration roller (P = .03) and vibration roller and control (P < .001). There was also a significant difference between the nonvibration roller and control (P < .001). For knee ROM, there was no significant difference between the vibration and nonvibration roller (P = .31). A significant difference was found between the vibration roller and control group (P < .001) and nonvibration roller and control group (P < .001).

CONCLUSION

The results suggest that a vibration roller may increase an individual's tolerance to pain greater than a nonvibration roller. This investigation should be considered a starting point for future research on this technology.

Both ipsilateral and contralateral localized vibratory stimulations modulated pain-related sensory thresholds on the foot in mice and humans

Purpose

This study was aimed to investigate the effect of localized vibration on sensory thresholds in mice and humans using a novel quantitative method.

Participants and methods

The sensory thresholds of 7-week-old male C57BL/6J mice were measured with four sine-wave electrostimulation frequencies (5, 50, 250, and 2,000 Hz) before and after applying 2-minute vibration to the plantar side of the foot in mice. In human participants (16 males and 16 females; mean age, 21.0±0.8 years), the sensory threshold was measured at 50 Hz before and after applying 2-minute and 5-minute vibrations to the dorsal side of the foot.

Results

Application of a 2-minute vibration at either the ipsilateral or contralateral side modulated the sensory thresholds elicited by a 5- or 50-Hz right electrostimulation in mice. In human participants, application of a 5-minute vibration at either the ipsilateral or contralateral side modulated the sensory threshold elicited by 50-Hz right electrostimulation, but had no effect on local skin temperature. These results suggest that the right side of pain-related Aδ fibers (50 Hz) or C fibers (5 Hz) was modulated by the localized ipsilateral or contralateral side of vibratory stimuli, respectively, in mice and humans.

Conclusion

The ability of contralateral vibration to modify the right sensory thresholds suggests possible involvement of the central nervous system in vibratory modulation.

Can whole body vibration exercises affect growth hormone concentration? A systematic review

Whole body vibration (WBV) has been recognized as an effective alternative exercise modality to resistance exercise for its ability in enhancing force and power, generating capacity in skeletal muscle, increasing bone mass and improving cardiovascular function. Since the effect of WBV exercises on growth hormone (GH) levels has been never compared and discussed, the aim of this study was to review systematically the literature to verify the WBV effects on GH concentration. By using PubMed, Scopus and PEDRo databases with the keywords 'growth hormone' or GH and 'whole body vibration' or WBV, we found and analysed 12 papers (182 subjects recruited), verifying their level of evidence (National Health and Medical Research Council hierarchy of evidence) and the methodological quality (PEDRo scale). Although WBV induced GH responses in nine out of 12 publications, caution should be however taken when considering the results due to the markedly different methodologies among these publications.

Effect of localised vibration on muscle strength in healthy adults: a systematic review

OBJECTIVE

To investigate the effects of local vibration on muscle strength in healthy adults.

DATA SOURCES

The electronic databases PubMed, CINAHL, Scopus and Web of Science were searched using a combination of the following keywords: vibration, vibration therapy, power, maximal voluntary contraction, performance, rate of force development and vibratory exercise. In addition, the Medical Subject Headings 'vibration', 'strength' and 'exercise' were used. The bibliographical search was limited to articles published in English.

STUDY SELECTION

Trials that evaluated the effect of localised vibration on muscle strength in healthy humans were included.

DATA EXTRACTION

Two independent evaluators verified the quality of the selected studies using the PEDro Scale and the Cochrane Collaboration's tool for assessing the risk of bias. Muscle strength was calculated for each intervention.

RESULTS

In total, 29 full-text studies were assessed for eligibility. Eighteen studies did not match the inclusion criteria, and were excluded. The 11 studies included in this review had an average PEDro score of 5.36/10. Most of the studies reported significant improvements in muscle strength after the application of local vibration. There was considerable variation in the vibration training parameters and target muscle location.

CONCLUSIONS

The use of local vibration on the target muscle can enhance muscle strength in healthy adults. Further well-designed controlled studies are required to confirm the effect of local vibration training on muscle strength.

Do whole body vibration exercises affect lower limbs neuromuscular activity in populations with a medical condition? A systematic review

BACKGROUND

The use of surface electromyography (sEMG) to evaluate muscle activation when executing whole body vibration exercises (WBVE) in studies provide neuromuscular findings, in healthy and diseased populations.

OBJECTIVES

Perform a systematic review of the effects of WBVE by sEMG of lower limbs in non-healthy populations.

METHODS

The search using the defined keywords was performed in PubMed, PEDRo and EMBASE databases by three independent researchers. Applying the PRISMA statement several studies were selected according to eligibility criteria and organized for the review. Full papers were included if they described effects of WBVE for the treatment of illnesses, evaluated by sEMG of lower limbs independently on the year of the publication; in comparison or associated with other treatment and evaluation techniques.

RESULTS

Seven publications were selected; two in spinal cord injury patients, one in Friedreich's ataxia patients, three in stroke patients and one study in breast cancer survivors. Reported effects of WBV in were muscle activation by sEMG and also on strength, blood flow and exercise resistance; even in paretic limbs.

CONCLUSION

By the use of sEMG it was verified that WBVE elicits muscle activation in diseased population. These results may lead to the definition of exercise protocols to maintain or increase muscular activation. However, due to the heterogeneity of methods among studies, there is currently no consensus on the sEMG signal processing. These strategies might also induce effects on muscle strength, balance and flexibility in these and other illnesses.