Whole body vibration

X-ray of spondylosis of the lumbar spine.

Workplace exposures to whole-body vibrations for long durations can lead to musculoskeletal problems of many kinds.[10] Problems of the neck and lower back in particular can be common for operators of heavy equipment including construction, forestry, agriculture, and trucking. Other occupations where whole-body vibrations may be present include aircraft operators, sea vessel workers, drivers of public transportation like trains and buses.

Farmers with long-term exposure to whole body vibration and mechanical shocks have a higher prevalence of back pain (compared to those not exposed to vibration), and the prevalence increases with vibration dose.[11] Long-term exposure affecting the whole body leads to spinal degeneration (spondylosis) and increased risk of low back pain.[12][13]

Factors that affect the occupational exposure to whole-body vibration include the frequency of vibrations, the magnitude of vibrations, the daily exposure to vibrations, the standing or seating posture of the operator, the direction of the vibration, and how tightly coupled the human is to the source of the vibration.[14] Exposure limits and estimates have been characterized in the ISO 2631-1[15] for whole-body vibration. Measurements of vibration exposure are usually taken at the human/vibration interface.

Injured patients can be exposed to shocks and vibrations during transport which can worsen patient conditions due to involuntary motions of the body. Many forms of immobilization devices are used to limit this motion with varying degrees of success.[16][17][18] Common modes of patient transport include hand carried stretcher (litter), ground ambulance, and air medical services which all contain multiple forms of shocks and whole-body vibrations.

Measurements are taken with accelerometers to estimate the amount of vibration exposure to the human body. These measurements are taken at the human body or at the vibration source or surface.[14] Measurements of different directions are taken to relate the motion direction with the response of the human body.[19] Specifically, transfer functions can be used to determine the human response to the vibration.[20] Measurement techniques for estimating exposures to whole body vibrations and hand-arm vibration have been developed in International Standards.[21][22]

The immediate predecessor of modern vibration training is Rhythmic Neuromuscular Stimulation (RNS). In former East Germany Biermann was experimenting with the use of cyclic massage and its effects on trunk flexion back in the sixties (Biermann, 1960[23]).

The technique has been tested on turkeys in the hope of finding a benefit that could be used for astronauts.[24] Engineering issues came into play when they tried to upgrade the test machine to support the weight of a human being. Once the vibration intensity grew strong enough to lift over 40 kg, fractures appeared in the steel. The first bed-rest study using a vibration training device for humans was done by the European Space Agency (ESA) in 2003 in Berlin[25] (Berlin Bedrest Study, BBR). The same technology was then used in several parabolic flight campaigns of the DLR (German Aerospace Agency) starting in 2006 where the feasibility of use of a lightweight vibration training device under microgravity conditions was demonstrated and ein 2009 and 2010 where basic research on influence of microgravity on vibration training effects was investigated.[26][27]

Since 1961, NASA has been testing adding light vibrations to exercise equipment and systems to minimize vibration transmission of existing exercise devices to the space station, like the Treadmill Vibration Isolation System (TVIS) and the Cycle Ergometer Vibration Isolation System (CEVIS). Any company referencing NASA directly in its marketing campaigns is misleading and has no relevance to the discipline of vibration training.

The first Galileo machine patent was filed in 1996 in the same year the first Galileo device was commercially available.[28][29] In 1996, the first Galileo vibrating dumbbell patent was filed.[30]

While it is not yet clear if whole body vibration produces the same health benefits as regular physical exercise, [4] it has been proven to provide significant health benefits, including decreased resting heart rate and blood pressure and improved cardiac function.[31]

While it has been shown that whole body vibration at high frequencies can cause low back pain, studies have illustrated that at low frequencies (below 20 Hz), it can be effective in reducing back pain. A 2019 randomized control trial indicated that low frequency vibration can help people with non specific low back pain (NSLBP) by reducing symptoms and improving joint proprioception.[31]

A 2018 meta-analysis showed that whole body vibration can improve bone mineral density in the lumbar spine and femoral neck of postmenopausal women younger than 65.[32] A 2019 publication evaluated the benefits of whole body vibration in pediatric oncology patients. Whole body vibration applied at frequencies ranging from 12 to 30 Hz was shown to improve balance and muscle strength of several muscle groups in the legs. This review concluded that whole body vibration is a therapeutic modality that can offset functional impairments in children with cancer. Whole body vibration should be used in conjunction with an exercise therapy program to promote an active lifestyle.[33]

A review in 2014 concluded that there is little and inconsistent evidence that acute or chronic whole body vibration could improve the performance of competitive or elite athletes.[34]

Cochrane reviews have concluded that there is insufficient evidence of effect of whole body vibration training on functional performance of people with neurodegenerative disease,[35] or in disease-related problems in people with fibromyalgia.[36]

Vibrating platforms fall into different, distinct categories. The type of platform used is a moderator of the effect and result of the training or therapy performed (Marin PJ, Rhea MR, 2010[37]). Main categories of machine types are:

1. High Energy Lineal, found mostly in commercial vibration training studios and gyms. The vibration direction is lineal/upward
2. Premium Speed Pivotal, (teeter-totter movement) used for physiotherapy work at lower speeds and exercise workouts at “premium” speed, up to 30 Hz. Both commercial and home units are available.
3. Medium Energy Lineal, the majority of lineal platforms produced. These are usually made of plastic; some have 3-D vibration which is low quality.
4. Low Speed Pivotal units.

Other machine types are low Energy/Low amplitude lineal and Low energy/High amplitude lineal.

Concerning the z-movements, two main types of system can be distinguished (Marin PJ et al. 2010,[37] Rittweger 2010,[38] Rauch 2010[39]) :

• Side alternating (pivotal) systems, operating like a see-saw and hence mimicking the human gait where one foot is always moving upwards and the other one downwards, and
• Linear systems where the whole platform is mainly doing the same motion, respectively: both feet are moved upwards or downwards at the same time.

Systems with side alternation usually have a larger amplitude of oscillation and a frequency range of about 5 Hz to 40 Hz. Linear/upright systems have lower amplitudes but higher frequencies in the range of 20 Hz to 50 Hz. Despite the larger amplitudes of side-alternating systems, the vibration (acceleration) transmitted to the head is significantly smaller than in non side-alternating systems (Abercromby et al. 2007[40]) while at the same time muscle activation even at identical vibration parameters are increased in pivotal systems.[41]

Mechanical stimulation generates acceleration forces acting on the body. These forces cause the muscles to lengthen, and this signal is received by the muscle spindle, a small organ in the muscle. This spindle transmits the signal through the central nervous system to the muscles involved (Abercromby et al. 2007,[40] Burkhardt 2006[42]).

Power Plate is a brand of vibrating platform consisting of a vibrating base, which may vibrate up and down approximately 1 to 2 millimetres (39 to 79 thou) (1/16") 25 to 50 times per second.[43] The machine is large enough to accommodate a person in deep squat. Traditional exercises such as squats and push-ups can be done on the vibrating base.[44]

Galileo (in the US up until 2014 also available as Vibraflex) is a brand of vibration training platforms used as exercise equipment as well as for therapeutic use. It consists of a vibration platform which vibrates sinusoidal side alternating like a see-saw. Depending on the device size it oscillates with an amplitude of up to 6 mm (equivalent to a peak to peak distance of 12 mm) and a frequency of 5 Hz to 40 Hz (5 to 40 repetitions per second). Galileo is manufactured in Germany by the German company Novotec Medical GmbH. Since 2004 Galileo is also available as a medical device.

The base plate of Galileo vibration training devices is moving like a see-saw. This side alternating motion is supposed to mimic human gait in order to utilize nearly physiological motion patterns close to the side alternating human gait. The side alternation causes the hip to tilt which requires the contra lateral muscles of the back to be activated – while one leg is lifted the other drops.[45] Compared to vertically vibrating devices the side alternating motion results in very low acceleration acting on the centre of gravity of the upper body and the head.[46][40][47]

A vibrating belt machine (also Mueller belt machine, belt massager, or jiggler machine) is an exercise machine that uses a vibrating belt, to be used around the waist or buttocks.