Weeks Of Whole-body Vibration Research Articles

High-acceleration whole body vibration stimulates cortical bone accrual and increases bone mineral content in growing mice

Whole body vibration (WBV) is a promising tool for counteracting bone loss. Most WBV studies on animals have been performed at acceleration <1g and frequency between 30 and 90Hz. Such WBV conditions trigger bone growth in osteopenia models, but not in healthy animals. In order to test the ability of WBV to promote osteogenesis in young animals, we exposed seven-week-old male mice to vibration at 90Hz and 2g peak acceleration for 15min/day, 5 days/week. We examined the effects on skeletal tissues with micro-computed tomography and histology. We also quantified bone vascularization and mechanosensitive osteocyte proteins, sclerostin and DMP1. Three weeks of WBV resulted in an increase of femur cortical thickness (+5%) and area (+6%), associated with a 25% decrease of sclerostin expression, and 35% increase of DMP1 expression in cortical osteocytes. Mass-structural parameters of trabecular bone were unaltered in femur or vertebra, while osteoclastic parameters and bone formation rate were increased at both sites. Three weeks of WBV resulted in higher blood vessel numbers (+23%) in the distal femoral metaphysis.After 9-week WBV, we have not observed the difference in structural cortical or trabecular parameters. However, the tissue mineral density of cortical bone was increased by 2.5%.Three or nine weeks of 2g/90Hz WBV treatment did not affect longitudinal growth rate or body weight increase under our experimental conditions, indicating that these are safe to use.These results validate a potential of 2g/90Hz WBV to stimulate trabecular bone cellular activity, accelerate cortical bone growth, and increase bone mineral density.

The Effects Of A 10-week Whole-body Vibration Program On Balance And Lower Body Muscular Strength In Adult Women.

: The purpose of this study was to examine the effects of 10 weeks of whole-body vibration on balance, lower body muscular strength, and bone mineral density in women. The study was comprised of two groups: whole body vibration (WBV, n = 19) and control (CON, n = 16). Both groups completed a 10-week WBV program. The WBV group received a vibratory stimulus while performing lower extremity exercises. The CON group performed the same protocol without vibration. Data were collected on balance, muscular strength and bone mineral density. Two, factorial MANOVAs were used to analyze the data with a significance level of .05. Isometric strength of the quadriceps increased significantly for both groups. The improvement in strength was significantly greater in the WBV group (pre: 128.7 ± 50.8 ft•lb, post: 157.7 ± 51.9 ft•lb) compared to the control group (pre: 129.3 ± 33.9 ft•lb, post: 136.5 ± 33.8 ft•lb). No significant differences were observed between the groups for any other variables. Both groups showed significant improvements over time in the adaptation test (WBV pre: 61.53 ± 3.28 deg/s, post: 52.74 ± 3.37 deg/s; CON pre: 68.19 ± 3.6 deg/s, post: 65.44 ± 3.67 deg/s) and the rising index of the sit-to-stand test (WBV pre: 29.32 ± 9.2 %BW, post: 31.32 ±10.5 %BW; CON pre: 29.81 ± 9.4 %BW, post: 33.3 ± 7.9 %BW). In conclusion, adding WBV to a lower extremity exercise program appears to improve lower body muscular strength.

Whole-Body Vibration Partially Reverses Aging-Induced Increases in Visceral Adiposity and Hepatic Lipid Storage in Mice.

At old age, humans generally have declining muscle mass and increased fat deposition, which can increase the risk of developing cardiometabolic diseases. While regular physical activity postpones these age-related derangements, this is not always possible in the elderly because of disabilities or risk of injury. Whole-body vibration (WBV) training may be considered as an alternative to physical activity particularly in the frail population. To explore this possibility, we characterized whole-body and organ-specific metabolic processes in 6-month and 25-month old mice, over a period of 14 weeks of WBV versus sham training. WBV training tended to increase blood glucose turnover rates and stimulated hepatic glycogen utilization during fasting irrespective of age. WBV was effective in reducing white fat mass and hepatic triglyceride content only in old but not in young mice and these reductions were related to upregulation of hepatic mitochondrial uncoupling of metabolism (assessed by high-resolution respirometry) and increased expression of uncoupling protein 2. Because these changes occurred independent of changes in food intake and whole-body metabolic rate (assessed by indirect calorimetry), the liver-specific effects of WBV may be a primary mechanism to improve metabolic health during aging, rather than that it is a consequence of alterations in energy balance.

Does short-term whole-body vibration training affect arterial stiffness in chronic stroke? A preliminary study.

[Purpose] Previous studies have shown that stroke is associated with increased arterial stiffness that can be diminished by a program of physical activity. A novel exercise intervention, whole-body vibration (WBV), is reported to significantly improve arterial stiffness in healthy men and older sedentary adults. However, little is known about its efficacy in reducing arterial stiffness in chronic stroke. [Subjects and Methods] Six participants with chronic stroke were randomly assigned to 4 weeks of WBV training or control followed by cross-over after a 2-week washout period. WBV intervention consisted of 3 sessions of 5 min intermittent WBV per week for 4 weeks. Arterial stiffness (carotid arterial stiffness, pulse wave velocity [PWV], pulse and wave analysis [PWA]) were measured before/after each intervention. [Results] No significant improvements were reported with respect to carotid arterial stiffness, PWV, and PWA between WBV and control. However, carotid arterial stiffness showed a decrease over time following WBV compared to control, but this was not significant. [Conclusion] Three days/week for 4 weeks of WBV seems too short to elicit appropriate changes in arterial stiffness in chronic stroke. However, no adverse effects were reported, indicating that WBV is a safe and acceptable exercise modality for people with chronic stroke.

Effects of whole body vibration on body composition and muscle strength of children with Down syndrome

Background and purpose: Children with Down syndrome(DS) have an increased prevalence of obesity and muscle weakness. The aim of this study was to investigate the effects of a 12 weeks of whole body vibration (WBV)on body composition and muscle strength of children with DS. Subjects and methods: Thirty children with DS, aged 10-12 years, divided randomly into two groups of equal numbers(control and study groups)participated in this study. The control group received a designed physical therapy program, while the study group received the same program given to the control group, in addition to WBV training. Treatment sessions were performed 3 times per week, for 3 successive months. Measurements of body composition, isometric strength of hip flexors ,extensors, abductors, knee extensors, flexors and ankle planter flexors before and after the treatment program .Results: The results revealed that body composition, including body weight, body mass index(BMI), waist circumference ,fat mass and percentage of body fat did not change significantly for both groups. There was significant increase in lower limb strength in both groups when comparing their pre and post treatment results .Comparison of post treatment results revealed more increase in lower limb strength in the WBV group .This study showed that 12 weeks WBV training did not affect body composition. However, WBV training induced a gain in lower limb strength. Conclusion :These preliminary results suggest that WBV training may improve lower extremities muscular strength in obese children with DS.

Comparing the effects of whole-body vibration to standard exercise in ambulatory people with Multiple Sclerosis: a randomised controlled feasibility study

Objectives: This study aimed firstly to investigate the feasibility of the study protocol and outcome measures, secondly to obtain data in order to inform the power calculations for a larger randomised controlled trial, and finally to investigate if whole-body vibration (WBV) is more effective than the same duration and intensity of standard exercises (EXE) in people with Multiple Sclerosis (PwMS). Design: Randomised controlled feasibility study. Setting: Outpatient MS centre. Subjects: Twenty seven PwMS (age mean (SD) 48.1 (11.2)) with minimal gait impairments. Interventions: Twelve weeks of WBV or standard EXE, three times weekly. Main measures: Participants were measured with isokinetic muscle strength, vibration threshold, Timed Up and Go test (TUG), Mini-BESTest (MBT), 6 Minute Walk test (6MWT), Multiple Sclerosis Impact Scale 29 (MSIS 29), Modified Fatigue Impact Scale (MFIS) and Verbal Analogue scale for sensation (VAS) pre and post 12 week intervention. Results: WBV intervention was found feasible with low drop-out rate (11.1%) and high compliance (90%). Data suggest that a sample of 52 in each group would be sufficient to detect a moderate effect size, with 80% power and 5% significance for 6 minute walk test. Large effect sizes in favour of standard exercise were found for vibration threshold at 5th metatarsophalangeal joint and heel (P=0.014, r= 0.5 and P=0.005, r=0.56 respectively). No between group differences were found for muscle strength, balance or gait (P>0.05). Conclusions: Data suggest that the protocol is feasible, there were no adverse effects. A trial including 120 people would be needed to detect an effect on walking endurance.

Repeated exposure to high-frequency low-amplitude vibration induces degeneration of murine intervertebral discs and knee joints.

High-frequency, low-amplitude whole-body vibration (WBV) is being used to treat a range of musculoskeletal disorders; however, there is surprisingly limited knowledge regarding its effect(s) on joint tissues. This study was undertaken to examine the effects of repeated exposure to WBV on bone and joint tissues in an in vivo mouse model. Ten-week-old male mice were exposed to vertical sinusoidal vibration under conditions that mimic those used clinically in humans (30 minutes per day, 5 days per week, at 45 Hz with peak acceleration at 0.3g). Following WBV, skeletal tissues were examined by micro-computed tomography, histologic analysis, and immunohistochemistry, and gene expression was quantified using real-time polymerase chain reaction. Following 4 weeks of WBV, intervertebral discs showed histologic hallmarks of degeneration in the annulus fibrosus, disruption of collagen organization, and increased cell death. Greater Mmp3 expression in the intervertebral disc, accompanied by enhanced collagen and aggrecan degradation, was found in mice exposed to WBV as compared to controls. Examination of the knee joints after 4 weeks of WBV revealed meniscal tears and focal damage to the articular cartilage, changes resembling osteoarthritis. Moreover, mice exposed to WBV also demonstrated greater Mmp13 gene expression and enhanced matrix metalloproteinase-mediated collagen and aggrecan degradation in articular cartilage as compared to controls. No changes in trabecular bone microarchitecture or density were detected in the proximal tibia. Our experiments reveal significant negative effects of WBV on joint tissues in a mouse model. These findings suggest the need for future studies of the effects of WBV on joint health in humans.

Effects of amplitudes of whole-body vibration training on left ventricular stroke volume and ejection fraction in healthy young men

Objective:The aim of this study was to evaluate the effects of different whole-body vibration (WBV) training amplitudes on left ventricular stroke volume and ejection fraction in healthy young men.Methods:A total of 24 healthy men (age 21.71±1.49 year, height 176.17±6.61 cm, weight 70.73±10.08 kg, BMI 22.36±3.57 kg/m2, and body surface area 1.87±0.13 m2) were divided into two groups: high and low amplitude vibration (n=12). The vibration training consisted of 8 weeks of WBV 3 times a week with amplitudes of 2 or 4 mm and progressive frequencies from 20 Hz with increments of 5 Hz weekly. As outcome measures, left ventricular stroke volume and ejection fraction at baseline and after 8 weeks were evaluated. Mann-Whitney U test was used for the comparison between groups; Wilcoxon signed-ranks tests were used to compare pretest and post-test results in each group. A p value less than 0.05 was considered significant.Results:Whole-body vibration training with low amplitude (2 mm) caused an numerically increase in stroke volume (pre-test: 72.42±14.34; posttest: 78.42± 23.19 cm3; p=0.06) and ejection fraction (pre-test: 65.22±3.41; post-test: 67.00±4.18%; p=0.52). So; the increase was not significant. In the high-amplitude (4 mm) group, post-test results were nearly unchanged compared to the pre-test results. No significant difference was evident between groups.Conclusion:The intensity and volume of whole-body vibration training were not enough to affect systolic function.

Adaptations in physiological properties of rat motor units following 5 weeks of whole-body vibration

The purpose of the study was to determine the effects of 5-week whole-body vibration (WBV) on contractile parameters and force-frequency relationship of functionally isolated motor units of the rat medial gastrocnemius muscle: fast fatigable (FF), fast fatigue-resistant (FR), and slow (S). Moreover, myosin heavy chain isoform content was quantified. Following WBV, the maximum tetanic force of FF units was increased by ∼25%. The twitch half-relaxation time in all types of motor units and the twitch contraction time in FR units were shortened. The twitch-to-tetanus force ratio was decreased and the force-frequency curves were shifted rightwards in S and FR units. Myosin heavy chain distribution was not changed. These findings suggest modifications of the excitation-contraction coupling towards shortening of a twitch contraction. The observed increase in force of FF units may contribute to gains in muscle dynamic strength reported following WBV treatment.

Effects of whole body vibration training on body composition in adolescents with Down syndrome

The present study aimed to determine the effect of 20 weeks of whole body vibration (WBV) on the body composition of adolescents with Down syndrome (DS). Thirty adolescent with DS were divided into two groups: control and WBV. Whole body, upper and lower limbs body fat and lean body mass were measured with dual energy X-ray absorptiometry (DXA) before and after 20 weeks of WBV training. Repeated measures of ANOVA adjusting by height, weight and Tanner stage were used to analyze possible group by time interactions on body composition. The adjusted percentages of change in body composition were also compared between control and WBV groups. No group by time interactions were found for any variable, but the WBV group showed a higher reduction in body fat at the upper limbs (p<0.05), and a tendency toward higher percent increase in whole body lean body mass. Overall, a 20-week WBV training is not enough by itself for increasing lean body mass in adolescents with DS, but it might be helpful for improving body composition in this population. Its relationship with health and autonomy enhances the importance of these results.

The Effect of Whole-Body Vibration on Jump Height and Active Range of Movement in Female Dancers

Whole-body vibration (WBV) has been shown to have beneficial effects on strength and power indices in sedentary and moderately trained individuals. The aim of this study was to investigate the effect of 4 weeks of WBV on jump height, active range of motion (AROM), and leg anthropometry in conservatoire dance students. Seventeen female dancers were randomly assigned to a control or intervention group. The intervention group trained for 30 seconds per position at a 35-Hz frequency, 8-mm displacement in the first 2 weeks, and 40 seconds at 40 Hz for the final 2 weeks, whereas the control group carried out the same exercises but without vibration stimulation. A significant (p < 0.01) difference in the intervention group was noted over time for vertical jump and active ROM. No significant changes over time were noted in the anthropometric data. In conclusion, WBV can be used as a beneficial supplemental training intervention to increase jump and active flexibility in highly trained dancers without corresponding increases in relative anthropometric data.

Vibration therapy in multiple sclerosis: a pilot study exploring its effects on tone, muscle force, sensation and functional performance

Objective: To examine the effectiveness of whole body vibration (WBV) on tone, muscle force, sensation and functional performance in people with multiple sclerosis. Design: A randomized cross-over pilot study. Setting: Revive MS Support Therapy Centre. Glasgow, UK. Subjects: Sixteen people with multiple sclerosis were randomly allocated to one of two groups. Intervention: Group 1 received four weeks of whole body vibration plus exercise three times per week, two weeks of no intervention and then four weeks of exercise alone three times per week. Group 2 were given the two treatment interventions in the reverse order to group 1. Main measures: Ten-metre walk, Timed Up and Go Test, Modified Ashworth Scale, Multiple Sclerosis Spasticity Scale (MSSS-88), lower limb muscle force, Nottingham Sensory Assessment and Multiple Sclerosis Impact Scale (MSIS-29) were used before and after intervention. Results: The exercise programme had positive effects on muscle force and well-being, but there was insufficient evidence that the addition of whole body vibration provided any further benefit. The Modified Ashworth Scale was generally unaffected by either intervention, although, for each group, results from the MSSS-88 showed whole body vibration and exercises reduced muscle spasms (P = 0.02). Although results for the 10-m walk and Timed Up and Go Test improved, this did not reach statistical significance (P = 0.56; P = 0.70, respectively). For most subjects sensation was unaffected by whole body vibration. Conclusion: Exercise may be beneficial to those with multiple sclerosis, but there is limited evidence that the addition of whole body vibration provides any additional improvements. Further larger scale studies into the effects of whole body vibration in people with multiple sclerosis are essential.

Whole-body vibration training increases muscle strength and mass in older women: a randomized-controlled trial

To determine whether 10 weeks of whole-body vibration (WBV) training has a significant effect on strength, muscle mass, muscle power, and mobility in older women, 26 subjects were randomly assigned to a WBV training group (n=13; mean age 79 years) and a control (CON) group (n=13; mean age 76 years). Maximal voluntary isometric contraction (MVIC) increased 38.8% in the WBV group, without changes in the CON group. Electromyographic activity of the vastus medialis (VM), the vastus lateralis, and the biceps femoris (BF) did not change in either group. Thigh muscle cross-sectional area increased significantly after training in VM (8.7%) and BF (15.5%). Muscle power at 20%, 40%, and 60% MVIC decreased from pre-test to post-test in the CON group; however, WBV training prevented the decrease in the WBV group. Consequently, mobility, measured by the Timed Up and Go test, increased significantly after training (9.0%) only in the WBV group. Ten weeks of lower limb WBV training in older women produces a significant increase in muscle strength induced by thigh muscle hypertrophy, with no change in muscle power. The adaptations to WBV found in the present study may be of use in counteracting the loss of muscle strength and mobility associated with age-induced sarcopenia.

WHOLE-BODY VIBRATION INDUCED ADAPTATION IN KNEE EXTENSORS; CONSEQUENCES OF INITIAL STRENGTH, VIBRATION FREQUENCY, AND JOINT ANGLE

It was hypothesized that both vibration frequency and muscle length modulate the strengthening of muscles that is assumed to result from whole-body vibration (WBV). Length of knee extensor muscles during vibration is affected by the knee joint angle; the lengths of the knee extensors increase with more flexed knee joint angles. In an intervention study 28 volunteers were randomly assigned to 1 of 4 groups. Each group received 4 weeks of WBV at 1 of 3 different frequencies (20, 27, or 34 Hz) or 1 of 2 different lengths of knee extensors. Voluntary, isometric knee extension moment-angle relationship was determined. Initially, stronger subjects reacted differently to WBV than weaker participants. In stronger subjects knee extension moment did not improve; in the weaker subjects considerable improvements were observed ranging from 10 to 50%. Neither vibration frequency nor muscle length during the intervention affected the improvements. In addition to strength, the knee joint angle at which the maximal joint moment was generated (optimal joint angle) was affected. When trained at short muscle lengths, optimal angle shifted to more extend joint position. WBV training at long muscle lengths tended to induce an opposite shift. The amount of this shift tended to be influenced by vibration frequency; the lower the vibration frequency the larger the shift. Shifts of optimal lengths occurred in both weaker and stronger subjects. This study shows that muscle length during training affects the angle of knee joint at which the maximal extension moment was generated. Moreover, in weaker subjects WBV resulted in higher maximal knee joint extension moments. Vibration frequency and muscle length during vibration did not affect this joint moment gain.

Effect of Whole Body Vibration Training on Lower Limb Performance in Selected High-Level Ballet Students

The aim of this study was to examine the effects of 8 weeks of whole body vibration (WBV) training on vertical jump ability (CMJ) and knee-extensor performance at selected external loads (50, 70, and 100 kg; leg-press exercise) in elite ballerinas. Twenty-two (age, 21.25 +/- 1.5 years) full-time ballerinas were assigned randomly to the experimental (E, n = 11) and control (C, n = 11) groups. The experimental group was submitted to WBV training 3 times per week before ballet practice. During the training period, the E and C groups undertook the same amount of ballet practice. Posttraining CMJ performance significantly increased in E group (6.3 +/- 3.8%, p < 0.001). Furthermore, E group showed significant (p < 0.05-0.001) posttraining average leg-press power and velocity improvements at all the external loads considered. Consequently, the force-velocity and power-velocity relationship shifted to the right after WBV training in the E group. The results of the present study show that WBV training is an effective short-term training methodology for inducing improvements in knee-extensor explosiveness in elite ballerinas.

Whole-Body Vibration Induced Adaptation in Knee Extensors; Consequences of Initial Strength, Vibration Frequency, and Joint Angle

It was hypothesized that both vibration frequency and muscle length modulate the strengthening of muscles that is assumed to result from whole-body vibration (WBV). Length of knee extensor muscles during vibration is affected by the knee joint angle; the lengths of the knee extensors increase with more flexed knee joint angles. In an intervention study 28 volunteers were randomly assigned to 1 of 4 groups. Each group received 4 weeks of WBV at 1 of 3 different frequencies (20, 27, or 34 Hz) or 1 of 2 different lengths of knee extensors. Voluntary, isometric knee extension moment-angle relationship was determined. Initially, stronger subjects reacted differently to WBV than weaker participants. In stronger subjects knee extension moment did not improve; in the weaker subjects considerable improvements were observed ranging from 10 to 50%. Neither vibration frequency nor muscle length during the intervention affected the improvements. In addition to strength, the knee joint angle at which the maximal joint moment was generated (optimal joint angle) was affected. When trained at short muscle lengths, optimal angle shifted to more extend joint position. WBV training at long muscle lengths tended to induce an opposite shift. The amount of this shift tended to be influenced by vibration frequency; the lower the vibration frequency the larger the shift. Shifts of optimal lengths occurred in both weaker and stronger subjects. This study shows that muscle length during training affects the angle of knee joint at which the maximal extension moment was generated. Moreover, in weaker subjects WBV resulted in higher maximal knee joint extension moments. Vibration frequency and muscle length during vibration did not affect this joint moment gain.

Low-level mechanical vibrations can influence bone resorption and bone formation in the growing skeleton

Short durations of extremely small magnitude, high-frequency, mechanical stimuli can promote anabolic activity in the adult skeleton. Here, it is determined if such signals can influence trabecular and cortical formative and resorptive activity in the growing skeleton, if the newly formed bone is of high quality, and if the insertion of rest periods during the loading phase would enhance the efficacy of the mechanical regimen. Eight-week-old female BALB/cByJ mice were divided into four groups, baseline control (n = 8), age-matched control (n = 10), whole-body vibration (WBV) at 45 Hz (0.3 g) for 15 min day−1 (n = 10), and WBV that were interrupted every second by 10 of rest (WBV-R, n = 10). In vivo strain gaging of two additional mice indicated that the mechanical signal induced strain oscillations of approximately 10 microstrain on the periosteal surface of the proximal tibia. After 3 weeks of WBV, applied for 15 min each day, osteoclastic activity in the trabecular metaphysis and epiphysis of the tibia was 33% and 31% lower (P <0.05) than in age-matched controls. Bone formation rates (BFR·BS−1) on the endocortical surface of the metaphysis were 30% greater (P <0.05) in WBV than in age-matched control mice but trabecular and middiaphyseal BFR were not significantly altered. The insertion of rest periods (WBV-R) failed to potentiate the cellular effects. Three weeks of either WBV or WBV-R did not negatively influence body mass, bone length, or chemical bone matrix properties of the tibia. These data indicate that in the growing skeleton, short daily periods of extremely small, high-frequency mechanical signals can inhibit trabecular bone resorption, site specifically attenuate the declining levels of bone formation, and maintain a high level of matrix quality. If WBV prove to be efficacious in the growing human skeleton, they may be able to provide the basis for a non-pharmacological and safe means to increase peak bone mass and, ultimately, reduce the incidence of osteoporosis or stress fractures later in life.

Cellular phenotyping of the mouse skeleton using synchrotron based nano-computed tomography

Whole body vibration (WBV) is a promising tool for counteracting bone loss. Most WBV studies on animals have been performed at acceleration <1g and frequency between 30 and 90 Hz. Such WBV conditions trigger bone growth in osteopenia models, but not in healthy animals. In order to test the ability of WBV to promote osteogenesis in young animals, we exposed seven-week-old male mice to vibration at 90 Hz and 2g peak acceleration for 15 min/day, 5 days/week. We examined the effects on skeletal tissues with micro-computed tomography and histology. We also quantified bone vascularization and mechanosensitive osteocyte proteins, sclerostin and DMP1. Three weeks of WBV resulted in an increase of femur cortical thickness (+5%) and area (+6%), associated with a 25% decrease of sclerostin expression, and 35% increase of DMP1 expression in cortical osteocytes. Mass-structural parameters of trabecular bone were unaltered in femur or vertebra, while osteoclastic parameters and bone formation rate were increased at both sites. Three weeks of WBV resulted in higher blood vessel numbers (+23%) in the distal femoral metaphysis.After 9-week WBV, we have not observed the difference in structural cortical or trabecular parameters. However, the tissue mineral density of cortical bone was increased by 2.5%.Three or nine weeks of 2g/90 Hz WBV treatment did not affect longitudinal growth rate or body weight increase under our experimental conditions, indicating that these are safe to use.These results validate a potential of 2g/90 Hz WBV to stimulate trabecular bone cellular activity, accelerate cortical bone growth, and increase bone mineral density.