***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND Although data from studies in animals demonstrated beneficial effects of whole-body vibration ( WBV ) therapy on bone , clinical trials in postmenopausal women showed conflicting results . OBJECTIVE To determine whether WBV improves bone density and structure . DESIGN A 12-month , single-center , superiority , r and omized , controlled trial with 3 parallel groups . ( Clinical Trials.gov registration number : NCT00420940 ) SETTING Toronto General Hospital , Ontario , Canada . PARTICIPANTS 202 healthy postmenopausal women with bone mineral density ( BMD ) T-scores between -1.0 and -2.5 who were not receiving prescription bone medications . INTERVENTION Participants were r and omly assigned to 1 of 3 groups ( 1:1:1 ratio ) by using a block-r and omization scheme and sealed envelopes . They were asked to st and on a low-magnitude ( 0.3 g ) 90-Hz or 30-Hz WBV platform for 20 minutes daily or to serve as control participants ; all participants received calcium and vitamin D. MEASUREMENTS Bone outcome assessors , who were blinded to group assignment , determined trabecular volumetric BMD and other measurements of the distal tibia and distal radius with high-resolution peripheral quantitative computed tomography and areal BMD with dual-energy x-ray absorptiometry at baseline and at 12 months . RESULTS 12 months of WBV therapy had no significant effect on any bone outcomes compared with no WBV therapy . For the primary outcome of tibial trabecular volumetric BMD , mean change from baseline was 0.4 mg/cm(3 ) ( 95 % CI , -0.4 to 1.2 mg/cm(3 ) ) in the 90-Hz WBV group , -0.1 mg/cm(3 ) ( CI , -1.0 to 0.8 mg/cm(3 ) ) in the 30-Hz WBV group , and -0.2 mg/cm(3 ) ( CI , -1.1 to 0.6 mg/cm(3 ) ) in the control group ( P = 0.55 ) . Changes in areal BMD at the femoral neck , total hip , and lumbar spine were also similar among the groups . Overall , low-magnitude WBV at both 90 and 30 Hz was well-tolerated . LIMITATIONS Adherence to WBV ranged from 65 % to 79 % . Double-blinding was not possible . CONCLUSION Whole-body vibration therapy at 0.3 g and 90 or 30 Hz for 12 months did not alter BMD or bone structure in postmenopausal women who received calcium and vitamin D supplementation BACKGROUND whole-body vibration training may improve neuromuscular function , falls risk and bone density , but previous studies have had conflicting findings . OBJECTIVE this study aim ed to evaluate the influence of vertical vibration ( VV ) and side-alternating vibration ( SV ) on musculoskeletal health in older people at risk of falls . DESIGN single-blind , r and omised , controlled trial comparing vibration training to sham vibration ( Sham ) in addition to usual care . PARTICIPANTS participants were 61 older people ( 37 women and 24 men ) , aged 80.2 + 6.5 years , referred to an outpatient falls prevention service . METHODS participants were r and omly assigned to VV , SV or Sham in addition to the usual falls prevention programme . Participants were requested to attend three vibration sessions per week for 12 weeks , with sessions increasing to six , 1 min bouts of vibration . Falls risk factors and neuromuscular tests were assessed , and blood sample s collected for determination of bone turnover , at baseline and following the intervention . RESULTS chair st and time , timed-up- and -go time , fear of falling , NEADL index and postural sway with eyes open improved in the Sham group . There were significantly greater gains in leg power in the VV than in the Sham group and in bone formation in SV and VV compared with the Sham group . Conversely , body sway improved less in the VV than in the Sham group . Changes in falls risk factors did not differ between the groups . CONCLUSIONS whole-body vibration increased leg power and bone formation , but it did not provide any additional benefits to balance or fall risk factors beyond a falls prevention programme in older people at risk of falls OBJECTIVE To test whether training on a high-frequency ( 28Hz ) vibrating platform improves muscle power and bone characteristics in postmenopausal women . DESIGN R and omized controlled trial with 6-month follow-up . SETTING Outpatient clinic in a general hospital in Italy . PARTICIPANTS Twenty-nine postmenopausal women ( intervention group , n=14 ; matched controls , n=15 ) . INTERVENTION Participants stood on a ground-based oscillating platform for three 2-minute sessions for a total of 6 minutes per training session , twice weekly for 6 months . The controls did not receive any training . Both groups were evaluated at baseline and after 6 months . MAIN OUTCOME MEASURES Muscle power , calculated from ground reaction forces produced by l and ing after jumping as high as possible on a forceplate , cortical bone density , and biomarkers of bone turnover . RESULTS Over 6 months , muscle power improved by about 5 % in women who received the intervention , and it remained unchanged in controls ( P=.004 ) . Muscle force remained stable in both the intervention and control groups . No significant changes were observed in bone characteristics . CONCLUSION Reflex muscular contractions induced by vibration training improve muscle power in postmenopausal women Background Whole-body vibration ( WBV ) is a new type of exercise that has been increasingly tested for the ability to prevent  bone fractures and osteoporosis in frail people . There are two currently marketed vibrating plates : a ) the whole plate oscillates up and down ; b ) reciprocating vertical displacements on the left and right side of a fulcrum , increasing the lateral accelerations . A few studies have shown recently the effectiveness of the up- and -down plate for increasing Bone Mineral Density ( BMD ) and balance ; but the effectiveness of the reciprocating plate technique remains mainly unknown . The aim was to compare the effects of WBV using a reciprocating platform at frequencies lower than 20 Hz and a walking-based exercise programme on BMD and balance in post-menopausal women .  Methods Twenty-eight physically untrained post-menopausal women were assigned at r and om to a WBV group or a Walking group . Both experimental programmes consisted of 3 sessions per week for 8 months . Each vibratory session included 6 bouts of 1 min ( 12.6 Hz in frequency and 3 cm in amplitude with 60 ° of knee flexion ) with 1 min rest between bouts . Each walking session was 55 minutes of walking and 5 minutes of stretching . Hip and lumbar BMD ( g·cm-2 ) were measured using dual-energy X-ray absorptiometry and balance was assessed by the blind flamingo test . ANOVA for repeated measurements was adjusted by baseline data , weight and age . Results After 8 months , BMD at the femoral neck in the WBV group was increased by 4.3 % ( P = 0.011 ) compared to the Walking group . In contrast , the BMD at the lumbar spine was unaltered in both groups . Balance was improved in the WBV group ( 29 % ) but not in the Walking group . Conclusion The 8-month course of vibratory exercise using a reciprocating plate is feasible and is more effective than walking to improve two major determinants of bone fractures : hip BMD and balance Purpose . To examine the effects of two doses of low-frequency ( 12 Hz ) , low-magnitude ( 0.3 g ) , whole body vibration on markers of bone formation and resorption in postmenopausal women . Methods . Women were recruited and r and omized into a sham vibration control group , one time per week vibration group ( 1 × /week ) , or three times per week vibration group ( 3 × /week ) . Vibration exposure consisted of 20 minutes of intermittent vibration for the 1 × /week and 3 × /week groups , and sham vibration ( < 0.1 g ) for the control group for eight weeks . Double-blinded primary outcome measures were urine markers of bone resorption : N-telopeptide X normalised to creatinine ( NTx/Cr ) and bone formation : bone-specific alkaline phosphatase ( ALP ) . Results . Forty-six women ( 59.8 ± 6.2 years , median 7.3 years since menopause ) were enrolled . NTx/Cr was significantly reduced ( 34.6 % ) in the 3 × /wk vibration group but not in the 1 × /wk vibration group compared with sham control ( P < .01 ) group . No effect of time or group allocation was observed on the bone formation marker ALP ( P = .27 ) . Conclusion . We have shown for the first time that low-frequency , low-magnitude vibration 3 × /week for eight weeks in postmenopausal women results in a significant reduction in NTx/Cr , a marker of bone resorption , when compared with sham vibration exposure OBJECTIVES We aim ed to clarify whether a short-term whole body vibration training has a beneficial effect on bone mass and structure in elderly men and women . DESIGN R and omised controlled trial . METHODS A total of 49 non-institutionalised elderly ( 20 men and 29 women ) volunteered to participate in the study . Participants who met the inclusion criteria were r and omly assigned to one of the study groups ( whole body vibration or control ) . A total of 24 elderly trained squat positioned on a vibration platform 3 times per week for 11 weeks . Bone-related variables were assessed by dual-energy X-ray absorptiometry and peripheral quantitative computed tomography . Two-way repeated measures one-way analysis of variance ( group by time ) was used to determine the effects of the intervention on the bone-related variables and also to determinate the changes within group throughout the intervention period . Analysis of covariance was used to test the differences between groups for bone-related variables in pre- and post-training assessment s and in the percentage of change between groups . All analysis were carried out including age , height , subtotal lean mass and daily calcium intake as covariates . RESULTS 11 weeks of whole body vibration training led to no changes in none of the bone mineral content and bone mineral density parameters measured by dual-energy X-ray absorptiometry through the skeleton . At the tibia , total , trabecular and cortical volumetric bone mineral density decreased significantly in the whole body vibration group ( all P<0.05 ) . CONCLUSIONS A short-term whole body vibration therapy is not enough to cause any changes on bone mineral content or bone mineral density and it only produces a slight variation on bone structure among elderly people Background and aims : Exercise may enhance the effect of alendronate on bone mineral density ( BMD ) and reduce chronic back pain in elderly women with osteoporosis . The aim of this study was to determine whether whole-body vibration exercise would enhance the effect of alendronate on lumbar BMD and bone turnover , and reduce chronic back pain in post-menopausal women with osteoporosis . Methods : Fifty post-menopausal women with osteoporosis , 55–88 years of age , were r and omly divided into two groups of 25 patients each : one taking alendronate ( 5 mg daily , ALN ) and one taking alendronate plus exercise ( ALN+EX ) . Exercise consisted of whole-body vibration using a Galileo machine ( Novotec , Pforzheim , Germany ) , at an intensity of 20 Hz , frequency once a week , and duration of exercise 4 minutes . The study lasted 12 months . Lumbar BMD was measured by dual energy X-ray absorptiometry ( Hologic QDR 1500W ) . Urinary cross-linked N-terminal telopeptides of type I collagen ( NTX ) and serum alkaline phos-phatase ( ALP ) levels were measured by enzyme-linked immunosorbent assay and st and ard laboratory techniques , respectively . Chronic back pain was evaluated by face scale score at baseline and every 6 months . Results : There were no significant differences in baseline characteristics , including age , body mass index , years since menopause , lumbar BMD , urinary NTX and serum ALP levels , or face scale score between the two groups . The increase in lumbar BMD and the reduction in urinary NTX and serum ALP levels were similar in the ALN and ALN+EX groups . However , the reduction in chronic back pain was greater in the ALN+EX group than in the ALN group . Conclusions : The results of this study suggest that whole-body vibration exercise using a Galileo machine appears to be useful in reducing chronic back pain , probably by relaxing the back muscles in post-menopausal osteoporotic women treated with alendronate Nonpharmacologic approaches to preserve or increase bone mineral density ( BMD ) include whole-body vibration ( WBV ) , but its efficacy in elderly persons is not clear . Therefore , we conducted the Vibration to Improve Bone in Elderly Subjects ( VIBES ) trial , a r and omized , placebo-controlled trial of 10 minutes of daily WBV ( 0.3 g at 37 Hz ) in seniors recruited from 16 independent living communities . The primary outcomes were volumetric BMD of the hip and spine measured by quantitative computed tomography ( QCT ) and biochemical markers of bone turnover .  We r and omized 174 men and women ( 89 active , 85 placebo ) with T-scores -1 
    Output:
    
Most review s including children and adolescents with compromised bone mass showed an improvement of BMD at lower limbs , lumbar spine , and whole body .
In conclusion , WBV interventions seem to help children and adolescents with compromised bone mass to increase their BMD , but these improvements are limited in postmenopausal women and there is insufficient evidence for young adults .