Vibration Exercise Fights osteoporosis and bone loss
Vibration Exercise Builds muscle strength
Vibration Exercise Eases joint pain
Vibration Exercise Burns Fat and Cellulite

Research shows that after vibration training (just one session!), there is a high excretion of Testosterone and Growth Hormone. There is also a drop in the stress hormone cortisol. This combination has favorable effects on muscle protein synthesis.

Effect of vibration training on Hormones:

• Testosterone: + 7%
• Human Growth Hormone: + 460%
• Cortisol: - 32%
  (Source: Bosco et al 2000)

www.vibrationfitness.ca

www.wholebodyvibration.ca

Body vibration therapy is helping people with spinal cord injuries build bone density and muscle tone.

Dayna Schultz looks as if there is an earthquake going on under her feet. She stands ramrod-straight, teeth clenched, gripping a gray walker for support as her body shakes like a jackhammer, the walker every so often slipping off the side of the large metal plate she is on.

Yet for all the motion, Schultz, 19, of Morris, Minn., is calm. The vibrations she experiences aren't the result of seismic shifting. They're part of a therapy called whole body vibration. The Rehabilitation Institute of Michigan is using it to help increase bone density, reduce spasms and build muscle tone in people who have suffered spinal cord injuries. Madonna and members of the Detroit Lions are proponents, too.

High-frequency vibration for fitness now is being marketed and used as a way to help everyday athletes become more fit as well as for injury recovery programs like the one at the Rehabilitation Institute of Michigan, which uses a machine called the Wave. Some fitness centers across the country are starting to offer whole body vibration machines; a popular version is called the VibraSlim.

The machines used in whole body vibration look somewhat like StairMasters -- with a large metal plate where the steps would be. You stand on the plate and select a frequency and a segment time (usually from 30 to 60 seconds); the plate vibrates, causing your muscles to contract. That's supposed to lead to better circulation, fewer spasms and increased bone density. Users can also do basic moves like calf raises, squats, push-ups or sit-ups to work different body parts.

"For someone who can't make muscle contractions, this does the contractions for them," says Bill Thornton, the head physical trainer at the Rehabilitation Institute's Center for Spinal Cord Injury Recovery.

Thornton, 41, of Dearborn Heights will be monitoring the effects of whole body vibration as part of an institute study.
Schultz is using the machine as a part of her therapy after a car accident left her with no feeling below her torso and a broken neck. She's been a part of the Detroit-based Rehabilitation Institute's Center for Spinal Cord Injury Recovery since August. The crash -- a collision with a train that killed two people -- occurred last year. She uses a wheelchair, but also is working to stand again."I really had to work hard at standing up," Schultz says after trying to stand on the vibration machine for the first time last week. "You feel it a lot more when you're on there." At the Healing Retreat, a medical spa in Bloomfield Hills, a Vibration machine is used to help increase circulation and flexibility in users, says Katie Drinkard, the company's manager.

Some of those who use the machine are recovering from injuries, while others include it as a part of massage treatments. Drinkard says she's noticed whole body vibration helping to alleviate back and knee pain in some clients and to increase range of motion in a woman who uses it on a shoulder injury. It's also a quicker way to exercise, she says. Others, like Thea Rosa, of Cool, Calif., who was injured two years ago when the horse she was riding fell on her, find that whole body vibration helps to stimulate body parts that have lost sensation. She's been at the institute since June. Rosa started using the Wave in August, when the machine arrived, and now is on it at least three times a week.

"I can feel the tingling in my heels now," says Rosa, 39, after a session on the machine that included push-ups off the plate. "It's kind of a nice feeling when you're connected again to your body. You can feel the muscles work."

The benefits of whole body vibration are mostly short-term at this point. Rosa, who struggles with severe tightening of the muscles in her legs, says using the machine helps to fatigue her muscles and reduce spasms. But that usually only lasts about an hour. More research is needed on the long-term effects of whole body vibration, says Larry Leigh, director of research and training at WAVExercise, the Windsor-based company that sells a version of the vibration machine. And while whole body vibration might be useful as a part of fitness program, it's not enough on its own.

Still, Rosa credits whole body vibration for much of her progress in the past few months. "My hamstrings are getting stronger; my glutes are getting stronger," she says. She started riding horses again about four months after her accident. Now she wants to walk again.

"With this machine, I can feel the muscles contract and I can stand longer," says Rosa. "It gives you a boost. It's not impossible on my own, but it's a lot harder."

By: CECILIA OLECK

Whole body vibration has been recently proposed as an exercise intervention because of its potential forincreasing force generating capacity in the lower limbs. Its recent popularity is due to the combined effects on the neuromuscular and neuroendocrine systems. Preliminary results seem to recommend vibration exercise as a therapeutic approach for sarcopenia and possibly osteoporosis. This review analyses state of the art whole body vibration exercise techniques, suggesting reasons why vibration may be an effective stimulus for human muscles and providing the rationale for future studies.

Abbreviations: WBV, whole body vibration; WBVT, whole body vibration training

Keywords: whole body vibration; vibration exercise; neuromuscular performance

Vibration is a mechanical stimulus characterised by an oscillatory motion. The biomechanical variables that determine its intensity are the frequency and amplitude. The extent of the oscillatory motion determines the amplitude (peak to peak displacement, in mm) of the vibration. The repetition rate of the cycles of oscillation determines the frequency of the vibration (measured in Hz).

Vibration has been studied extensively for its dangerous effects on humans at specific amplitudes and frequencies. On the other hand, recent work has suggested that low amplitude, low frequency mechanical stimulation of the human body is a safe and effective way to exercise musculoskeletal structures. In fact, increases in muscular strength and power in humans exercising with specially designed exercise equipment have been reported.1–7 In particular, the effects of whole body vibrations (WBVs) have been studied with subjects exercising on specially designed vibrating plates producing sinusoidal vibrations (fig 1). The exercise devices currently available on the market deliver vibration to the whole body by means of oscillating plates using two different systems: (a) reciprocating vertical displacements on the left and right side of a fulcrum; (b) the whole plate oscillating uniformly up and down.

WBV exercise devices deliver vibrations across a range of frequencies (15–60 Hz) and displacements from <1 mm to 10 mm. The acceleration delivered can reach 15 g (where 1 g is the acceleration due to the Earth’s gravitational field or 9.81 m/s2). Considering the numerous combinations of amplitudes and frequencies possible with current technology, it is clear that there are a wide variety of WBV protocols that could be used on humans. Vibration exercise is quite a new topic in sport science. Many athletes and fitness and rehabilitation centres are using vibration in their exercise programmes, but current knowledge on appropriate safe and effective exercise protocols is very limited, and claims made by companies and pseudo-experts can be misleading.

The purpose of this review is to analyse the potential mechanisms by which muscles respond to vibration and to summarise current knowledge of the effects of vibration on human strength and power performance.

VIBRATION AND MUSCLE ACTIVATION: THE MUSCLE TUNING HYPOTHESIS
Evidence for muscle tuning requires information on the nature of the input force, the vibration response of the tissue, and the level of muscle activity. These can be difficult to measure because vibrations induced in the tissues can cause movement artefacts, which may interfere with measurement of muscle activity. Nonetheless, in a study of hand held vibrating tools,12 it was found that activation of the triceps brachii was greatest between vibration frequencies of 8 and 16 Hz, coinciding with the resonant frequencies measured at the wrist and elbow (10–20 Hz). In a similar experiment, vibration was recorded directly from the soft tissue groups in the lower extremities while subjects stood on a vibration platform.18 The natural frequencies for the tissues for each posture were determined by measuring the vibration response to a complex vibration covering a range of frequencies and therefore accounted for changes in resonance that occurred with altered limb posture and muscle activity. The vibration response of the soft tissues was measured for a range of input vibration frequencies (10–65 Hz), and it was found that most vibration damping occurred at the resonant frequencies of the tissues, concurring with the highest levels of muscle activity. The responses of the lower extremities to continuous vibrations or sequences of single, impact-like input were similar. This suggests that the body has a strategy to minimise its vibrations regardless of the mode of the input force.18 These studies support the muscle tuning paradigm, but these concepts should be tested further. For instance, the effect of the amplitude of the input vibrations on the tuning response has not yet been determined. Is there a minimum amplitude below which the body is not triggered to respond? At high vibration amplitudes, the maximum damping from the tissues will not be as effective at dissipating the vibration energy. We do not yet know the most effective range of vibration amplitudes that can be applied safely while eliciting a significant tuning response.

Training protocols and sporting equipment that cause specific alterations in muscle activity during exercise may have important implications for athletic training, rehabilitation after injury, and competitive performance. For instance, the hardness of a shoe midsole causes changes in the time to peak impact force at heel strike.19–22 This time and the associated loading rate are a correlate of the major frequency content of the impact force; impact forces that drive the soft tissues of the lower extremity closer to resonance cause increases in muscle activity and vibration damping from those tissues.23 It is conceivable that different types of equipment may be designed in future: training equipment, which promotes increased muscle activity, and competition equipment, which reduces the muscle activity required for vibration damping and thus allows more of the muscle activity to be used for the sporting task. Vibration platforms are the most recent example. They have been developed with the idea of promoting muscle activity, hence providing an effective training stimulus. Are they effective?

METABOLIC EFFECTS OF VIBRATIONS
The possibility of using vibrations as an effective training tool can be considered a recent idea. However, it should be noted that early work by Whedon et al24 reported some positive effects of oscillating beds on plaster immobilised patients. The possibility of using vibration in an athletic setting was introduced relatively recently by Russian scientists, who developed specific devices to transmit vibratory waves from distal to proximal links of muscle groups, mainly during the performance of isometric exercises.25 Recently many studies have been conducted with the aim of understanding the acute and chronic responses to WBV training (WBVT).

WBVT has been shown to cause clear metabolic responses similar to other forms of exercise. In a study by Rittweger et al,26 WBVT to exhaustion with an extra weight showed an O2 uptake of less than 50% of VO2MAX. An acute reduction in vertical jump was observed, suggesting that vibration exercise to fatigue can impair neuromuscular performance. The early impairment of muscle performance was shown to be recovered 20 seconds after the end of the fatiguing vibratory exercise. Another experiment conducted by Kerschan-Schindl et al27 showed a significant increase in muscle blood volume in the calf and thigh and a significant increase in mean blood flow velocity in the popliteal artery after vibration exercise on a vibrating plate (26 Hz, 3 mm amplitude). The mean blood flow measured by Doppler ultrasound increased from 6.5 to 13 cm/s, and this acute response was attributed mainly to the effect of vibrations in reducing the viscosity of blood and increasing its speed through the arteries. The above studies seem to indicate that WBVT may represent a mild form of exercise for the cardiovascular system.26–28 However, owing to the relatively low level of stimulation, it is unlikely that an athletic population could benefit from such a training stimulus if the aim is to improve cardiovascular performance. However, elderly people could make use of this form of exercise when other solutions are not possible. Also, because of its reported beneficial effects in reducing low back pain,29 pain sensation, and pain related limitation, it may be a viable alternative for a patient who cannot run and/or lift weights. However, the extensive literature on the dangerous effects of WBV on the spine (for a review, see Cardinale and Pope30) suggests that more, well controlled, long term intervention studies are needed before WBVT can be prescribed for patients with low back pain.

CONCLUSIONS
The current evidence indicates that WBVT may be an effective exercise intervention for reducing the results of the ageing process in musculoskeletal structures. It would also appear that vibration may be an effective countermeasure to microgravity and disuse. However, it is important to conduct further studies to understand the neurophysiological mechanisms involved in muscle activation with vibration in order to be able to prescribe safe and effective WBVT programmes. Not only the optimal frequency and amplitude need to be identified but also the level of muscle activation that would benefit more from vibration stimulation. Considering current WBVT technology, it is possible to confirm that the procedure seems safe when subjects stand on vibrating plates for a relatively short time with knees semiflexed to limit transmission of vibrations to the head. However, when vibration transmission frequency is too high, some can experience motion sickness-like symptoms.50 As we know from occupational medicine that prolonged exposure to WBVT can have major negative effects on health, proper care should be taken when exercise programmes are prescribed so as to guarantee safety.

British Journal of Sports Medicine 2005;39:585-589; doi:10.1136/bjsm.2005.016857
© 2005 by BMJ Publishing Group Ltd & British Association of Sport and Exercise Medicine