Whole Body Vibration and Bone Mass - Research Paper Example

Whole Body Vibration and Bone Mass Critical Review of Literature Effect of whole body vibration (WBV) on PTH in elderly s. Martna, G., de Saaa, Y., Da Silva-Grigolettob, ME., Vaamondec, D., Sarmientoa, S., and Garca-Mansoa, JM., (2009) Aim: To investigate the response of parathormone (PTH) to mechanical vibration stimuli and consequent changes in the basal calcium and phosphate concentrations following a low and very-low intensity short-term training in 16 elderly female participants of mean age 69. Method: Randomised controlled trial involving 16 elderly women, randomised into experimental group (n=8) and control group (n=8) based on strict inclusion criteria. They were exposed to whole body vibration on a vibrating platform for 24 sessions 3 times a week. On the vibrating platform, both the groups performed two dynamic exercises and one static exercise, and the frequency of vibration was progressively increased in the exercise group to 20-32 Hz while the control group always received 10 Hz. The outcome measures were serum PTH, calcium, phosphate, and beta crosslap along with anthropometry and a 30-second chair test. Results: The serum PTH concentration increased significantly in the experimental group by 44.3%, but the responses of blood calcium, phosphate, and beta-cross lap had no significantly demonstrable change. In both the groups, the 30-second chair test showed significant changes in the strength level of both the groups with considerable change in the experimental group. Anthropometric data demonstrated usefulness of training in the experimental group. Critique: The details of the power calculation have not been given, and given the small size of samples in each group, the reader have a chance to doubt the reliability and validity of the data collected. The exclusion criteria given tend to exclude any other confounding factors that may influence PTH, calcium, phosphate, or vitamin D metabolism. These may demonstrate only the effects of WBV in the intervention population. There were both anthropometric measurements and clinical assessments before and after the training protocol, and the details have been given in this study. The details of the laboratory assessments indicate that the authors chose a state of the art investigative measure. The exercise regimens and workup schedule also indicate involvement of all the muscle groups. The details of the WBV training sessions had been given in separate tables, and the results have been discussed. Appropriate statistical analysis has been undertaken with complementary pre-post test analysis of physical condition and anthropometry with statistically significant changes demonstrated through increase in PTH levels. The effects lesser intensity WBV had no significant effects, although there were no increases in circulating calcium or phosphate levels. It can be argued that this study could have determined the time variations in calcium and phosphate levels with the changes in the PTH levels, but the design did not incorporate that. As a result, it is not possible to say whether these changes in PTH could at all lead to bone mineralisation. The authors admit that as a limitation of this study that this study could not determine whether the rise in PTH level with WBV could achieve its main objective of accomplishing improvement in bone mineralisation. The rise in PTH may also lead to increase rate of bone demineralisation, but concurrent estimation of pro-collagen I levels do not show bone degradation. The small sample size poses another limitation, which confounds the effects of exercise in improving the strength of the muscles; however, despite these limitations, this study reveals the positive effects of WBV in bone mineralisation in the elderly population (Martna et al., 2009, 1-6). 2. Effects of Whole-Body Vibration Exercise on Lower-Extremity Muscle Strength and Power in an Older Population: A Randomized Clinical Trial. Rees, SS., Murphy, AJ., Watsford, ML., (2008). Aim: To investigate the effects of vibration exercises on strength or force-producing capacity and power on healthy older adults of average age of 73.7 years. Method: Randomised controlled study design involving 30 participants randomised into two groups. Each group consisted of 15 participants, with one group having vibration exercise training (VIB) and another group on an exercise without vibration training. Interventions consisted of 3 sessions per week for 8 weeks. Outcome measures consisted of measurement of isokinetic flexor and extensor strengths and powers of the hip, knee, and ankle. Results: The VIB group significantly improved ankle flexor plantar strength and power in comparison to exercise only group. In terms of knee flexor and extensor strengths, there were no much of a difference between these groups. Critique: The generalisability of the results may be limited due to a small sample size, despite the fact that the sample size was predetermined through measures of effect size from prior literature. It can be argued that an appropriate sample size with larger population included could indicate more variations so the gain in power and strength of hip and knee groups of muscles could have been significant, but that is not possible in this study. This indicates the need for further studies. Moreover, this population may have other otherwise unrecognised diseases in the hips and knees, which may limit their improvement in knee and hip groups of muscles, and the design does not incorporate a protocol that precludes these diseases. Moreover, this study cannot provide any indication to the mechanism of such changes so a clear conclusion can be arrived at about the prescription of such WBV exercises in these individuals. Further studies are warranted. (Rees, Murphy, and Watsford, 2008, 462-470). 3. High-Frequency Whole-Body Vibration Improves Balancing Ability in Elderly Women. Cheung, W., Mok, H., Qin, L, Sze, P., Lee, K., Leung, K., (2007). Aim: To investigate the efficacy of high-frequency whole-body vibrations (WBV) on the balancing ability in 69 elderly women. Method: Randomised controlled trial where 69 community-living elderly women aged 60 or above without habitual exercise were randomised into either high-frequency whole body vibration (WBV) or no-treatment control group. Side-alternating WBV at 20Hz with 3 minutes a day, 3 days a week for 3 months in the WBV intervention group was used as an intervention with the control group remaining sedentary with normal daily life. main outcome measures were limits of stability in terms of reaction time, movement velocity, directional control, end-point excursion, maximum excursion, and the functional reach test at baseline and at end point. Results: In the experimental group statistically significant enhancement of stability was detected in movement velocity, directional control, and maximum point excursion. Critique: The main limitation of the study was bias in the control group in relation to intervention. Dummy machines were not available for the control group and thus the population in the control group was just sedentary, although this limitation was attempted to be minimised by monitoring of their involvement in habitual exercise or supervised exercise. The subjects who exceeded the amount of exercise were not recruited in this study. Moreover, there is a fault in sampling design, whereby, there was an overestimation of the attrition rate in the intervention group leading to a number imbalance between the control and the intervention groups (Cheung et al., 2007, 852-857). 4. Whole-Body-Vibration Training Increases Knee-Extension Strength and Speed of Movement in Older Women. Roelants, M., Delecluse, C., and Verschueren, SM. (2004) Aim: The authors aimed to investigate the effects of 24 weeks of whole body vibration (WBV) training on knee extension strength and speed of movement and on counter-movement jump performance in older women of age group 58-74. Method: Randomised controlled trial involving 89 postmenopausal women, off hormone replacement therapy of age group 58 to 74. Random assignment was done to a WBV group (n=30), a resistance training (RES) group (n=30) and a control group (n=29). The WBV and RES groups performed training 3 times a week for 24 weeks. WBV group performed unloaded static and dynamic knee extensor exercises on vibration platform expected to provoke reflexive muscle activity. The RES group performed dynamic leg press and leg extension exercises in order to train knee extensors increasing from 20 repetitions maximum to high 8 repetitions maximum. The control group did not participate in any training. Measurements were taken at baseline, at 12 weeks and at 24 weeks of isometric strength and dynamic strength of knee extensors using a dynamometer. Using external resistance equivalents to 1%, 20%, 40%, and 60% of isometric maximum, speed of movement of knee extension was assessed. Counter-movement jump performance was measured with a contact mat. Results: Isometric and dynamic knee extensor strengths increased significantly in WBV group and the RES group after 24 weeks of training with insignificant differences of training effects between the groups. At low resistance, the speed of movement of knee extension significantly increased in the WBV group only with no significant differences in training effects between the intervention groups. Counter-movement jump height enhanced significantly in both the groups, with all these changes perceptible after 12 weeks of training. Critique: Although this study indicates strength gain after WBV training and RES, it is to be remembered that the relative training load in the RES programme was individually tuned. This does not determine whether in WBV training an individualised training programme would optimise the effect on strength. Moreover, the RES was designed to optimise the strengths, not to maximise it. 5. Effects of whole body vibration training on postural control in older individuals: A 1 year randomized controlled trial. Bogaerts, A., Verschueren, S., Delecluse, C., Claessens, AL., Boonen, S., (2007) Aim: To investigate the effects of a 12-month WBV training programme on postural control on healthy older adults. Method: Randomised controlled trial involving 220 people who were randomly assigned WBV programme (n=94), a fitness group (n= 60), and a control group (n=66). The WBV and the fitness groups trained three times a week for 1 year with respectively performing exercises on a vibration platform and cardiovascular, strength, balance, and stretching exercises. Dynamic computerized posturography was used to assess balance at baseline, 6 months, and 12 months. The outcome measures were sensory organization test, motor control test, and adaptation test. Results: Whole body vibration training was associated with reduced falls on a moving platform with disturbed vision, and improvements in the response to toes down rotations at the ankle was noted. The fitness group also showed reduced falls frequency on a moving surface when vision was disturbed. Critique: This test was done on healthy older adults; however, there is a question whether this test was challenging enough for their age groups. Thus it may not reflect any significant changes that may support or refute the hypothesis. The SOT test has been criticised by others that this test does not detect subtle changes. Moreover within the study design, all the recruits had no baseline balance problems, and hence may be inadequate for this study. Since both the intervention groups demonstrated similar results on balance, it may be argued that the people with WBV may as well have the effects due to exercises which had been demonstrated in the FIT group. People who are frail elderly may demonstrate different findings altogether, since this study becomes significant only when it has the purpose of prevention falls fulfilled. Moreover elderly suffered from knee pain, which might have compromised their performances in WBV (Bogaerts et al., 2007, 309-316). 6. Treatment of Chronic Lower Back Pain with Lumbar Extension and Whole-Body Vibration Exercise: A Randomized Controlled Trial. Rittweger, J., Just, K., Kautzsch, K., Reeg, P. and Felsenberg, D. (2002). Aim: This study was designed to compare lumbar extension exercises and WBV exercises for chronic lower back pain. Design: A randomised controlled trial with a 6-month followup involving 60 patients of mean age 51.7 years with chronic lower back pain with a pain history of average 13.1 years without any specific spinal disease. These participants performed either vibration (n=25) exercise for 3 months or isodynamic lumbar extension exercises (n=25) for 3 months. The outcome measures were lumbar extension torque, pain sensation measured by visual analogue scale, and pain related disability measured by pain disability index. Results: There were significant and comparable reduction in pain sensation and pain related disability in both the groups. In the vibration group, the lumbar extension torque increased significantly, but significantly more so in the lumbar extension group. Correlation was not established between gain in lumbar torque and pain relief and improvement in pain related disability. Critique: Regarding recruitment of subjects, there were no baseline differences in baseline demographics, except in age and height. However to know the effects appropriately, it is required to have a design that compare groups with same age and height. Moreover, in the lumbar exercise group training and assessment of force and motility needed 4 measurement units and 18 exercise units, and that in the vibration exercise group were only 4 measurements. The end term data may be a reflection of uninhibited motor output due to relief of pain, but there had been no measures in the design to obviate that (Rittweger et al., 2002, 1829-1834) References Bogaerts, A., Verschueren, S., Delecluse, C., Claessens, AL., Boonen, S., (2007). Effects of whole body vibration training on postural control in older individuals: A 1 year randomized controlled trial, Gait & Posture, 26; 309-316 Cheung, W., Mok, H., Qin, L, Sze, P., Lee, K., Leung, K., (2007). High-Frequency Whole-Body Vibration Improves Balancing Ability in Elderly Women. Arch Phys Med Rehabil;88:852-7. Martna, G., de Saaa, Y., Da Silva-Grigolettob, ME., Vaamondec, D., Sarmientoa, S., and Garca-Mansoa, JM., (2009). Effect of whole body vibration (WBV) on PTH in elderly subjects, Rev Andal Med Deporte; 2 (1):1-6. Rees, SS., Murphy, AJ., Watsford, ML., (2008). Effects of Whole-Body Vibration Exercise on Lower-Extremity Muscle Strength and Power in an Older Population: A Randomized Clinical Trial. Physical Therapy Volume 88 Number 4, 462-470. Rittweger, J., Just, K., Kautzsch, K., Reeg, P. and Felsenberg, D. (2002). Treatment of Chronic Lower Back Pain with Lumbar Extension and Whole-Body Vibration Exercise: A Randomized Controlled Trial. SPINE Volume 27, Number 17, pp 1829-1834. Roelants, M., Delecluse, C., and Verschueren, SM. (2004). Whole-Body-Vibration Training Increases Knee-Extension Strength and Speed of Movement in Older Women. JAGS 52:901-908 Read More