***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: OBJECTIVE To investigate the acute effects of long-term whole-body vibration on leg muscle performance and functional capacity in persons with multiple sclerosis . DESIGN A r and omized controlled trial . SUBJECTS Twenty-five patients with multiple sclerosis ( mean age 47.9 ± 1.9 years ; Exp and ed Disability Status Scale 4.3 ± 0.2 ) were assigned r and omly to whole-body vibration training ( n = 11 ) or to a control group ( n = 14 ) . METHODS The whole-body vibration group performed static and dynamic leg squats and lunges on a vibration platform ( 25 - 45 Hz , 2.5 mm amplitude ) during a 20-week training period ( 5 training sessions per 2-week cycle ) , and the control group maintained their usual lifestyle . PRE- , MID- ( 10 weeks ) and POST- ( 20 weeks ) knee-muscle maximal isometric and dynamic strength , strength endurance and speed of movement were measured using isokinetic dynamometry . Function was determined through the Berg Balance Scale , Timed Up and Go , Two-minute Walk Test and the Timed 25-Foot Walk Test . RESULTS Leg muscle performance and functional capacity were not altered following 10 or 20 weeks of whole-body vibration . CONCLUSION Under the conditions of the present study , the applied 20-week whole-body vibration exercise protocol did not improve leg muscle performance or functional capacity in mild- to moderately impaired persons with multiple sclerosis during and immediately after the training programme According to experimental studies , low-amplitude high-frequency vibration is anabolic to bone tissue , whereas in clinical trials , the bone effects have varied . Given the potential of whole body vibration in bone training , this study aim ed at exploring the transmission of vertical sinusoidal vibration to the human body over a wide range of applicable amplitudes ( from 0.05 to 3 mm ) and frequencies ( from 10 to 90 Hz ) . Vibration-induced accelerations were assessed with  skin-mounted triaxial accelerometers  at the ankle , knee , hip , and lumbar spine in four males st and ing on a high-performance vibration platform .  Peak vertical accelerations of the platform covered a range from 0.04 to 19 in units of G ( Earth 's gravitational constant ) . Substantial amplification of peak acceleration could occur between 10 and 40 Hz for the ankle , 10 and 25 Hz for the knee , 10 and 20 Hz for the hip , and at 10 Hz for the spine . Beyond these frequencies , the transmitted vibration power declined to 1/10th-1/1000 th of the power delivered by the platform . Transmission of vibration to the body is a complicated phenomenon because of nonlinearities in the human musculoskeletal system . These results may assist in estimating how the transmission of vibration-induced accelerations to body segments is modified by amplitude and frequency and how well the sinusoidal waveform is maintained . Although the attenuation of vertical vibration at higher frequencies is fortunate from the aspect of safety , amplitudes > 0.5 mm may result in greater peak accelerations than imposed at the platform and thus pose a potential hazard for the fragile musculoskeletal system 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 Fourteen elite and 14 amateur athletes were subjected to vibratory stimulation during bilateral biceps curl exercises of explosive strength exertion . The athletes performed two separate series of three sets of exercises in r and om order . The second set of one series was administered with superimposed vibration of 44 Hz and an acceleration of about 30 m x s(-2 ) transmitted through the two-arms h and le to the arm muscles . The mechanical power of each repetition was measured by the ' Power Teach ' instrument . The maximal and mean power values for each set were automatically recorded and shown on the screen . The acute effect was evaluated as the difference between the mean and peak power output in the second ( with vibratory stimulation ) and first ( without vibratory stimulation ) sets . Similarly , the residual effect was taken to be the difference between the power values of the third ( after vibratory stimulation ) and the first ( before vibratory stimulation ) sets . The results were subjected to a repeated- measures analysis of variance with group as a between- participants factor . The results showed that exercise mode ( with vs without vibratory stimulation ) result ed in a significant immediate effect for mean power and for maximal power . The factor group ( elite vs amateurs ) result ed in a significant effect for maximal power only . The increase in explosive strength exertion attributed to vibratory stimulation was 30.1 and 29.8 W ( 10.4 % and 10.2 % ) for maximal and mean power respectively in the elite group , and 20.0 and 25.9 W ( 7.9 % and 10.7 % ) respectively in the amateur athletes . Vibratory stimulation result ed in an insignificant residual effect The Modified Ashworth Scale ( MAS ) is a clinical scale used to assess muscle spasticity . While the evidence indicates that the reliability of the MAS is better in the upper limb and in certain distal muscle groups , no investigation has compared the effect of limbs and muscle groups on the MAS reliability . This study aim ed to evaluate the effect of limb and muscle group on the reliability of the MAS in patients with spastic hemiplegia . Thirty subjects with upper and lower limb muscle spasticity were recruited for this trial . Two female experienced physiotherapists participated in this examination of reliability , and rated each patient in a r and omized order in a single session . For the intrarater reliability , the second rater repeated the test 1 week later . Shoulder adductor , elbow flexor , wrist flexor , hip adductor , knee extensor , and ankle plantar flexor were tested on the hemiplegic side . Results demonstrated moderate inter ( kappa=0.514 , SE=0.046 , p < 0.001 ) and intrarater ( kappa=0.590 , SE=0.051 , p<0.001 ) reliability . For the inter and intrarater reliability , the agreement obtained for the upper and lower limb was similar . In the upper limb , the agreement between raters on the distal wrist flexor was significantly higher than the agreement on the proximal shoulder adductor . In the lower limb , there was a similar agreement between raters on the distal ankle plantar flexor and proximal hip adductor . For within rater , the agreement on the proximal and distal muscles of both limbs was not statistically significant . The Modified Ashworth Scale had moderate reliability . The limbs had no effect on the reliability . The agreement on distal wrist flexor in the upper limb was significantly higher between rater than in the proximal shoulder adductor . The agreement obtained with the MAS was not good , which questions the validity of the measurements The objective of the study was to investigate the chronic effect of low frequency whole body vibration ( WBV ) on isometric and eccentric strength of knee extensors with different force exertion capacity . It was hypothesized that ( 1 ) four-week WBV intervention with the low frequency domain would enhance muscle strength and ( 2 ) the improvement would be more pronounced in the weaker muscle . To test our hypothesis twenty patients with acute stroke were recruited . Ten patients were r and omly assigned to vibration and the remaining ten patients served for control . The patients in the vibration group received WBV with 20 Hz frequency three times per week st and ing on a vibration platform in half squat position meanwhile flexing and extending the joints and placing the weight from one leg to the other . Knee extensor strength was determined under isometric and eccentric contraction before and after WBV intervention . Myoelectrical activity ( EMG ) of the vastus lateralis muscle was also measured . Significant improvement was revealed in the vibration group only . The maximum isometric torque and EMG activity increased significantly for both paretic and non-paretic leg , but the improvement was threefold greater in the vibration group . No significant alteration was found in rate of torque development . Maximum eccentric torque and EMG increased significantly for the paretic leg only . Mechanical work enhanced significantly in the paretic side only . The results of our study indicate that the selection of the effective vibration frequency depends upon the physical condition of neuromuscular system . Low vibration frequency intervention can increase the strength in weak muscles due to neuromuscular impairment and restricted physical activity The aim of this study was to analyze electromyography ( EMG ) responses of vastus lateralis muscle to different whole-body vibration frequencies . For this purpose , 16 professional women volleyball players ( age , 23.9 ± 3.6 years ; height , 182.5 ± 11.1 cm ; weight , 78.4 ± 5.6 kg ) voluntarily participated in the study . Vibration treatment was administered while st and ing on a vibrating platform with knees bent at 100 ° ( Nemes Bosco-system , Rome , Italy ) . EMG root mean square ( rms ) and was recorded for 60 seconds while st and ing on the vibrating plate in the following conditions : no vibrations and 30- , 40- , and 50-Hz vibration frequencies in r and om order . The position was kept for 60 seconds in each treatment condition . EMGrms was collected from the vastus lateralis muscle of the dominant leg . Statistical analysis showed that , in all vibration conditions , average EMGrms activity of vastus lateralis was higher than in the no-vibration condition . The highest EMGrms was found at 30 Hz , suggesting this frequency as the one eliciting the highest reflex response in vastus lateralis muscle during whole-body vibrations in half-squat position . An extension of these studies to a larger population appears worthwhile to further eluci date the responsiveness of the neuromuscular system to whole-body vibrations administered through vibrating platforms and to be able to develop individual treatment protocol In this study , we investigated a new method of training for maximal strength and flexibility , which included exertion with superimposed vibration ( vibratory stimulation , VS ) on target muscles . Twenty-eight male athletes were divided into three groups , and trained three times a week for 3 weeks in one of the following conditions : ( A ) conventional exercises for strength of the arms and VS stretching exercises for the legs ; ( B ) VS strength exercises for the arms and conventional stretching exercises for the legs ; ( C ) irrelevant training ( control group ) . The vibration was applied at 44 Hz while its amplitude was 3 mm . The effect of training was evaluated by means of isotonic maximal force , heel-to-heel length in the two-leg split across , and flex- and -reach test for body flexion . The VS strength training yielded an average increase in isotonic maximal strength of 49.8 % , compared with an average gain of 16 % with conventional training , while no gain was observed for the control group . The VS flexibility training result ed in an average gain in the legs split of 14.5 cm compared with 4.1 cm for the conventional training and 2 cm for the control groups , respectively . The ANOVA revealed significant pre-post training effects and an interaction between pre-post training and ' treatment ' effects ( P < 0.001 ) for the isotonic maximal force and both flexibility tests . It was concluded that superimposed vibrations applied for short periods allow for increased gains in maximal strength and flexibility OBJECTIVE To investigate the effects of whole body vibration in the elderly . DESIGN R and omized controlled trial . SETTING Nursing home . PARTICIPANTS Forty-two elderly volunteers . INTERVENTIONS Six-week vibration intervention plus physical therapy ( PT ) ( n=22 ) or PT alone ( n=20 ) . MAIN OUTCOME MEASURES We assessed gait and body balance using the Tinetti test ( maximum scores of 12 for gait , 16 for body balance , 28 for global score ) , motor capacity using the Timed Up & Go ( TUG ) test , and health-related quality of life ( HRQOL ) using the Medical Outcomes Study 36-Item Short-Form Health Survey ( SF-36 ) . RESULTS After 6 weeks , the vibration intervention group improved by a mean + /- st and ard deviation of 2.4+/-2.3 points on the gait score compared with no score change in the control group ( P < .001 ) . The intervention group improved by 3.5+/-2.1 points on the body balance score compared with a decrease of 
    Output:
    
No solid evidence was found concerning the effects of WBV on subgroups of people with specific stroke-related deficits due to the heterogeneity of patient groups .
Based on the review , there is insufficient evidence to support clinical use of WBV in enhancing body functions and structures , activity , and participation after stroke