The effect of vibration on EMGrms activity of skeletal muscle

The assessment of the neuromuscular behaviour has received in the last decades a strong improvement through the evolution of diagnostic technique. This was allowed by the creation of new dedicated instruments and apparatus that have been used mainly in the field of rehabilitation and sport medicine. However, the assessment of the neuromuscular functions is steel far to be enough complete for covering the large spectrum of biological changes which occurs with injures and after surgery. In fact, there is an high percentage of patients showing a weakness of the leg extensor muscles after a long follow-up period - most likely due to the severing of propioceptors during surgery (1).

Even if such problems are well known there is an inadequate and lack of specific evaluation technique that could allow the quantification and assessment of the impairment due to the proprioceptors inability to function properly. In this respect, it was conduced a pilot investigation to analyse the possibility for detecting and quantifying the operated knee joint propioceptors functional capacity. For this purpose a new diagnostic technique, consisting on monitoring the muscles EMGrms activity during vibration, was applied for identify altered neural strategies of motoneuron pool recruitment. Previous findings of EMGrms recorded in biceps brachii of boxers (2), showed a significant enhancement (P<0.001)>.

It has been demonstrated that vibration drives alpha - motoneurons via Ia loop producing force without descending motor drive (5). In addition, it has been shown that vibration-induced activation of muscle spindle receptors, not only in the muscle to which vibration was applied, but also to the neighbouring muscles (6). Mechanical vibration (10-200 Hz) applied to muscle belly or tendon can elicit reflex contraction (7). This response has been named “ tonic vibration reflex “ (TVR).

It has been also argued that in the presence of TVR, the vibration-induced suppression of motor output in maximal voluntary contractions probably does not depend to the voluntary command Methods of functional testing during rehabilitation exercises 22 (8). It was suggested that contributing mechanism might be vibration induced pre-synaptic inhibition and/or transmitter depletion in the group Ia exitatory pathways which constitute the afferent link of the gamma-loop (8). In light of the above findings, a pilot study was planned to introduce a new assessment strategy to identify muscle behaviour and possibly dysfunction.

Refferences:

1. Engel A, Petschnig R, Baron R, et al. (1990) The effect of meniscectomy on the strength of the femoral quadriceps muscle after more than 3 years.wien Klin Wochenschr 102, 22:663–6

2. Augustsson J, Esko A, Thomee R, et al. (1998) Weight training of the thigh muscles using closed ve open kinetic chain exercises : a comparison of performance enhancement. J Orthop Sports Phys Ther 27, 1: 3-8

3. Burke JR, Schutten MC, Koceja DM, et al. (1996). Age-dependent effects of muscle vibration and the Jendrassik maneuver on the patellar tendon reflex response. Arch Phys Med Rehabil 77 ,6:600-604

4. Lebedev MA, Peliakov AV (1991). Analysis of the interference electromyogram of human soleus muscle after exposure to vibration. Neirofiziologia 23, 1: 57-65 (article in Russian).

5. Rothmuller C, Cafarelli E (1995). Effects of vibration on antagonist muscle coactivation during progressive fatigue humans. J Physiol 485: 857-864

6. Kasai T, Kawanishi, Yahagi S (1992) The effects of wrist muscle vibration on human voluntary elbow flexionextension movements. Exp Brain Res 90: 217–220

7. Hagbarth KE, Eklund G(1965) Motor effects of vibratori stimuli. In: Granit R (Ed.) Muscular afferents and motor control. Proceedings of the First Symposium, Almqvist and Wiksell, Stockholm pp 177–86

8. Bongiovanni LG, Hagbarth KE, Stjenberg L (1990) Prolonged muscle vibration reducing motor output in maximal voluntary contractions in man. J Physiol (Lond) 423:15-23.

List of Publications

LIST OF PUBLICATIONS
- Bosco C., Cardinale M., Tsarpela O., Colli, R., Tihanyi J., von Duvillard S.P., Viru A. (1998). The influence of whole body vibration on jumping performance. Biology of Sport (15), 3: 157-164

- Bosco C., Cardinale M. (1998). Nuove frontiere dell’ allenamento sportivo : le vibrazioni. Effetti sul comportamento meccanico del muscolo scheletrico. Coaching & Sport Science Journal, 3 (1): 53-59

- Bosco, C., Colli, R., Introini, E., Cardinale, M., Tihanyi, J., von Duvillard S., & Viru, A.(1999). Adaptive responses of human skeletal muscle to vibration exposure. Clinical Physiology, (19), 2: 183-187

- Bosco C., Cardinale, M., Tsarpela O. (1999). Influence of vibration on mechanical power and electromyogram activity in human arm flexors muscles. European Journal of Applied Physiology, 79:306-311

- Bosco, C., Iacovelli, M., Tsarpela, O., Cardinale, M., Bonifazi, M., Tihanyi, J., Viru, A. (1999). Effect of acute whole body vibration treatment on mechanical power, electromyogram and hormonal profile of male athletes. In: Proceedings of the 4th Annual Congress of the European College of SportScience. Pp.279

- Bosco C., Colli, R., Cardinale M., Tsarpela O., Bonifazi, M., (1999). The effect of whole body vibration on mechanical behavior of skeletal muscle and hormonal profile. Musculo Skeletal Interactions; basic and clinical aspects. Volume 2: pp.67-76. Eds. GR Lyritis Hylonome Editions ISBN 960-86410-0-4

- Bosco, C., Cardinale, M., Tsarpela, O., & Locatelli, E. (1999). New trends in coaching science: The use of vibrations for enhancing performance. New Studies in Athletics, 14 (4):55-62

- Bosco, C., Iacovelli, M., Tsarpela, O., Cardinale, M., Manno, R., Tihanyi, J., Viru, M., De Lorenzo,A. & Viru, A. (2000). Hormonal responses to whole body vibrations in man. European Journal of Applied Physiology, 81 (6): 449-454

- Cardinale, M., (2000). Le vibrazioni: aspetti fisiologici ed effetti sul profilo ormonale. Scienza della Riabilitazione, 1 (1-2): 15-19 (ISSN 1590-6647)

- Cardinale, M., Andersson, H.(2000). Forbattring av prestations formagan genom vibrations training. Idrottforskning , 3 (9): 45-49

- Cardinale, M., Bosco, C. (in-press). The use of vibration as an exercise intervention. Exercise and Sport Sciences Reviews.

Training Effects of NEMES BOSCO

The benefits of using NEMES BOSCO-SYSTEM in sports training is unique. Athletes and coaches of different sports such as soccer, volleyball, basketball, track and field, boxing, tennis, skiing, baseball and more will find new ways to improve skills such as speed, power, strength, flexibility etc.

Vibration training can be applied simultaneously with other training methods in every stage of the preparation. Vibration training can be used in addition to the regular power training, or as a safe alternative to power training. It can also be used as a warming-up, to prepare for power training or in combination with technique training and/or speed-training.

A problem area in top-sport is training the explosive power, such as jumping power or throwing-power. Use is often made of 'brutal' training intensities and high 'peak' loads. This could be with heavy power loads of hundreds of kilos of weights, plyometric loads or drop-jumps. These unfortunately often result in injuries. Some examples are foot injuries, "Achilles" tendon injuries, knee injuries (jumpers knee) or back complaints. Vibration training is the key solution in these conditions.

Another issue is that the muscles become stronger after many years of training, but not the passive movement apparatus, like tendons, ligaments, joints and bones. Certainly for athletes who have reached the limits of their physical limits, it is extremely difficult to find effective and safe training methods. Vibration training allows the muscles to work very hard without overloading on the ligaments, tendons, joints and vertebra. This is not only to the benefit of top athletes, but also for young athletes, who are not able to take on strength training because of growing problems e.g. Osgood-Schlatter or M. Scheuermann, both disorders in bone growth that often appear in the teen years.

Vibration training using the NEMES BOSCO can be applied in a number of ways:
- Supplementary to the normal power training
- An alternative for power training, when there is injury or rehabilitation (for example: instead of power training, replace with vibration training)
- In preparation for power training (for example: first vibration training, and afterwards power training)
- In preparation for other types of training, such as technique training or speed training
- In preparation for competitions, as a warming-up; during track and field events, we often see the sprinters jumping or hopping up and down before they take up their positions in the starting blocks
- Cooling-down after training and contests, because of the positive effect on the blood circulation and the hormones, which helps the athlete to recover faster

NEMES has an impressive training effect on speed. Bosco et al (1990) showed improvements of 5.7% in power and 6.4% in speed after only one vibration training session. Conventional training did not show any performance improvement after one session. This improvement is typically only evident after at least 4 weeks of training!Power increases are also noticeable after a minimum of three sessions using the NEMES. Jump power and height achieved improved by 12% after a 10 day training programme using vibration training while no change was observed in the control group (Bosco et al 1998). In another study Bosco and colleagues (1999) found a 25% increase in arm power in international boxers following one vibration training session. Again the control group did not show any improvement and this type of gain is only evident from conventional training after several weeks. It is estimated that 100min vibration training is equal to 200 drop jumps from 60cm height, twice a week for 12 months !

Vibration Training Effects on Bones and Neurotransmiters

Bones:
Bone decalcification (osteoporosis) is one of the biggest health problems especially in the elderly and women population. Many elderly people break their bones more easily when they fall because of bone decalcification; the hip is the most notorious in this respect. The onset of osteoporosis is partly due to a lack of movement, which causes muscles to gradually weaken, the circulation to diminish and the bones to be inadequately used. In addition, as a result of the ageing process, the body produces fewer hormones such as testosterone, estrogen and growth hormone. Yet it is exactly these hormones, which play such an important role in the maintenance of strong bones.

The advice usually given to sufferers of this disease is to take more exercise, but that is difficult when muscles are weak, particularly in the legs. The NEMES BOSCO-SYSTEM offers a good alternative to vigorous impact exercise: through vibration the muscles automatically become stronger and regain their tone. The circulation improves because the blood vessels in the legs are wide open due to the vibration. At the same time, the pulsation gives a direct stimulus to bone tissue, which in turn stimulates the production of new bone tissue.

Scientific research shows that vibration training can help against osteoporosis. Recent findings show that even after only one vibration treatment, there is an increase in the hormone testosterone and growth hormone, which are so essential for strong bones.

Neurotransmitters:
Parkinson's Disease is an example of a deficiency in dopamine, which is the reason that L-Dopa is given as medicine. It is also recognized that serotonin plays a role in our mood, or frame of mind. A shortage of serotonin in the brain can lead to depression, which is the reason that Prozac is given as a medicine in order to increase the serotonin content in the brain. From research, it appears that vibration training also influences the neurotransmitters and the way in which they work. Vibration training increases the serotonin content in the brain, which could possibly explain why one feels so well after vibration training.

Biological Effects of Vibration Training

The NEMES BOSCO-SYSTEM is very effective. The reason of this is because while most therapies, methods of treatment or training, only work on a certain number of tissues or organs, the vibration given by the NEMES, which is also referred to as 'Whole-Body-Vibration' (WBV), actually vibrates the whole body. NEMES has a powerful positive effect on: muscle tissue, nerves, blood vessels, bones, fat tissue, cartilage, hormones and neurotransmitters.

Muscles:
The effect of vibration results in what scientific literature calls 'Tonic Vibration Reflex' or 'TVR'. That is a repeated myotatic reflex or stretch reflex. This means that the vibrated muscle has to work very hard, while the subject or player using the NEMES does nothing other than balance on the platform. The effect per pulsation is like that of the knee jerk reflex. This muscle activity can be measured by use of electromyography (EMG). For example, in a one repetition maximum effort, the muscle(s) involved are activated 100% voluntarily. However, with vibration training on the NEMES the muscles work at 200 to 300% of this 1RM activation. This is an ideal way to train, especially when the muscle does not function properly, for example with weakened muscles in the elderly, or after injuries.

Hormones:
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. In addition, increase in Growth Hormone excretion also results among others in a reduction of fatty tissue.

Effect of Vibration training on Hormones:
Testosterone: + 7%
Human Growth Hormone: + 460%
Cortisol: - 32% (Source: Bosco et al 2000)

Increases in Testosterone and Growth Hormone are important in the functioning of both body and mind. Many complaints of the elderly can be traced to a decrease in these hormones. It is essentially these hormones, together with the female hormone estrogen, which are used to combat geriatric complaints so that it is possible to still enjoy life and vitality even when one has reached old age.

Vibration Training and Human Performance

The improvement of the muscle performance after a short period of vibration training has been quoted (Bosco et al. 1998) to be similar to what occurs after several weeks of heavy resistance training (e.g. Coyle et al. 1981, Hakkinen and Komi 1985). In fact the improvement of the muscle functions after resistance training has been attributed to the enhancement of the neuromuscular behaviour caused by the increasing activity of the higher motor centre (Milner-Brownet al., 1975). The improvement of muscle performances induced by vibration training (VT) suggests that a neural adaptation has occurred in response to the vibration treatments. In this context, the duration of the stimulus seems to be both relevant and important. The adaptive response of human skeletal muscle to simulated hyper gravity conditions (1.1g) applied for only three weeks, caused a considerable improvement in the leg extensors muscle behaviour (Bosco 1985).

Thus it is likely that both neural adaptation and the length of the stimulus seem to play an important role in the improvement of muscle performances (e.g. Bosco, 1985). During the VT utilised for the research conducted on the boxers, the elbow flexors were stimulated for a total length of time of 300 seconds. The duration of the treatment was similar to that required to perform an elbow flexion for 600 repetitions with a load similar to 50/0 of the subject's body mass. Such an amount of repetitions would generally otherwise be distributed over 3 sessions a week with 50 repetitions per time, taking one month to complete. The large initial increases noted in muscle strength observed during the earlier weeks of intense strength training can be explained through increases in maximal neural activation (e.g. Moritani and De Vries, 1979). To explain how the increased neural output may occur is not as simple as how to explain the intrinsic mechanism of neural adaptation. Furthermore, a net excitation of the prime mover motoneurons could result from increased excitatory input, reduced inhibitory input or both (e.g. Sale, 1988).

After the VT period the EMG activity was found to be rather lower or to be the same as compared to the pre-treatment conditions even if, during the vibration, period an increment of neural input to the muscle occurred. In this respect the decrease in the ratio between EMG and mechanical power (EMG/P) demonstrated that VT induced an improvement of the neuromuscular efficiency of the muscles involved in the vibration treatment. Vertical jumping ability has been shown to increase following vibration treatment (Bosco et al. 1998; Bosco et al 1999). These improvements have been attributed to an enhancement of neural activity in the leg extensors muscles, together with an enhancement of the proprioceptors' feedback. During vibrations, the length of skeletal muscles changes slightly.

The facilitation of the excitability of spinal reflexes has been shown to be elicited by vibrations applied to the quadriceps muscle (Burke et al. 1996). Once again, the influence of vibrations on the neural drive of the la loop can play a crucial part in enhancing jumping performance following vibration treatments. Even if the adaptive responses of neuromuscular performance as measured by vertical jump tests cannot be fully explained, it is important to consider that the effectiveness of the stimulus can have both relevance and importance. The adaptive response of human skeletal muscle to simulated hyper gravity conditions (1.1 g), applied for only three weeks, caused a drastic enhancement of the neuromuscular functions of the leg extensors muscles (Bosco 1985). The regular use of centrifugal force (2 g) for 3 months has initiated conversion of muscle fibre type (Martin and Romond, 1975). In the experiments conducted, the total length of the WBV application period was not very long (from 7 minutes to 100 minutes), but the disturbance to the gravitational field was quite consistent (5.4 g).

An equivalent length and intensity of training stimulus (100 minutes) can only be reached by performing 200 drop jumps from 60 cm, twice a week for 12 months. In fact, the time spent for each drop jump is less than 200 ms, and the acceleration developed can barely reach 3.0 g (Bosco 1992). This means stimulating the muscles for 2 min per week for a total amount in one year of 108 minutes.
In a few words, vibrations can stimulate the biological system of athletes in the same way as strength training or explosive training and this stimulation can be applied in a much shorter period of time as compared to the time needed to perform traditional training sessions.

Scientific Basis of Vibrations

The facilitation of the excitability of the spinal reflex has been elicited through vibration of the quadriceps muscle (Burke et al. 1996). Lebedev and Peliakov (1991) have also suggested the possibility that vibrations may elicit excitatory inflow through muscle spin dle-motoneurons connections in the overall motoneuron inflow.

It has been demonstrated that vibration drives alpha-motoneurons via the la loop producing force without decreasing motor drive (Rothmuller and Cafarelli, 1995). Although it has been suggested that the vibration reflex, like the tendon jerk reflex, operates predominantly or exclusively on alpha motoneurons and does not utilise the same cortical originating efferent pathways as are used when performing voluntary contractions (Burke et al. 1976). It cannot be excluded that vibration treatments can also affect voluntary movements. These suggestions are supported by the present findings. In fact the EMG recorded in the biceps brachii of the experimental group in the study conducted on boxers showed a significant enhancement (P<0.001).

One of the first and major scientists who became interested in the effects of vibrations on human performance was Prof. Carmelo Bosco. The interest that Bosco had since 1992 (Belli and Bosco, Acta Physiol Scand 144, 1992) for the muscular response to mechanical stimulation, coupled with the more recent studies on hormones, paved the way to his last research topic: vibration, a force which we are unconsciously constantly exposed to. "Running, hunting, fighting, playing the drums and dancing, navigating the oceans, cutting trees and giving life to the first villages or travelling in a high speed train, men since always have been exposed to thousand types of vibration".

The concept of Neuro-Muscular Mechanical Stimulation (NEMES) is based on this brilliant intuition on how to use existing natural forces to improve our condition. Today this is the name of one of our innovative product lines based on the use of mechanical vibrations. Quickly a number of researches demonstrated the extraordinary effectiveness of this method bringing though also to light the importance of dosing the stimulation and the protocols on the base of highly individually characterized responses (Bosco et al., Biology of Sport, 15, 1998) (Bosco et al., Eur J Appl Physiol 79, 1999(Bosco et al., Clincal Physiol, 19, 1999) (Bosco et al., Eur J Appl Physiol, 81, 2000)And it is through these last researches that the patent that differentiates the NEMES products originates. The NEMES products are the only machines in the world equipped with an advanced system able to detect the muscular response to vibration through electromyography (EMG) and to identify the optimal vibration frequency for each subject.

From the studies on vibration emerges also the great stimulation that this method induces on bone tissue making it an optimal candidate for the prevention and cure of pathologies like osteoporosis. These studies open the road to a definition of new methodologies of training based on deep physiological knowledge.

How Does it Work..?

The NEMES BOSCO SYSTEM is a highly advanced computer-controlled system of training. It works in the following way: Acceleration in itself is an extremely intensive stimulus. At a frequency of 30 Hertz, for example, each pulsation is given an acceleration of 54m/s. In our example, it is applied 30 times per second. The frequency and the acceleration at an amplitude of about +/- 4mm results in a myotatic reflex or stretch reflex. This reflex activity is also referred to as a "Tonic Vibration Reflex" or 'TVR'. It is this mechanism which ensures an optimal increase in power.

The effect per pulsation is like that of the knee jerk reflex, which means activation of all muscles fibers (agonist and antagonists) in a way it does not exert any physical stress or load on the musculoskeletal system. It decreases the threshold of the type II muscle fibers, thus, they are recruited at the beginning of the desired motion and act together with the type I to achieve a tremendous change in the explosive power which mean a quick and strong desired motion.

All this is achieved in up to 10 repetitions of 1 minute. The same synchronisation of the central nervous system happens after passing the hard work of about one-month of intensive weight training. This muscle activity can be measured by electromyography (EMG). For example, in one repetition maximum effort, the muscle(s) involved are activated voluntarily at 100%. But with Vibration Training on the NEMES BOSCO-SYSTEM, the muscles work at 200% - 300% of this 1RM activation...! But in order to get this result the user needs to know his/her exact vibration training frequency. A simple electromyography (EMG) test prior the training session will give the information which frequency (Hz) to use. The NEMES BOSCO is the ONLY vibration training machine world wide, which can determine the training frequency of its user.

NEMES BOSCO Quality and Certifications

NEMES-BOSCO vibration training machines are born from the scientific need to discover and to improve the individual. By summarizing years of research this new training method maximize results safely and faster than ever before, making you save your most precious resource, time. And most importand of all... respecting individual differences!

NEMES-BOSCO vibration machines are certified with the highest European CE quality standards (CE 0434) as well as by ISO 9001:2000. In addition, the NEMES models LX-B, LC-B, LS-B and AT are classified as Class IIa Physical Therapy Devices by the Norwegian Ministry of Health and Social Affairs and DET NORSKE VERITAS (DnV).

Benefits from NEMES BOSCO Vibration Training

Vibration training is the latest scientific training approach for enhancing performance and speeding up recovery and rehabilitation. The method has been successfully applied by numerous national teams, professional athletes and sport clubs (NBA, FIFA, NFL, etc) rehabilitation centers, health, spa clubs and sports enthusiasts worldwide. Vibrations can stimulate the biological system of athletes in the same way as strength training or explosive training and this stimulation can be applied in a much shorter period of time as compared to the time needed to perform traditional training sessions. A single vibration training session is completed in as less than 10 minutes!

It opens a new window in sports and health science and gives coaches, doctors and other scientists new possibilities for studying and enhancing human performance and rehabilitation. Although resistance training effectiveness has been demonstrated due to the possibility of enhancing neuromuscular performance, power output, strength and hormonal profile, however, the time needed for these adaptations to occur is relatively long as compared to the possibilities offered by vibration treatments. A single vibration training session need only 10 minutes to complete!

Vibration training is an exciting tool of sports science and certainly it can be viewed as the "Next Step" in exercise approach.

NEMES BOSCO SYSTEM optimal vibration training

NEMES is the acronym of NEuro-muscular MEchanical Stimulation, a training method invented by the Italian Prof. Carmelo Bosco, who was a leading scientist in sports physiology. The method focuses on the maximization of stimuli to the neuromuscular system and bones, carefully dosed for each individual.

Prof. Bosco was the first scientist to prove to expose that every person has his own muscle frequency. NEMES-BOSCO is the most advanced and revolutionary training system for sports and health to-date, because it is designed to vibrate at the individually measured frequencies (Hz) of its users. This is accomplished through the internationally patented built-in electromyograph (EMG) measuring system.

NEMES is produced in different versions studied and designed specifically for different users. Since every human responds differently to the vibration stimuli, the use of our patented frequency detection system, based on electromyography (EMG), will allow each user to execute safe, effective and personalized training sessions.