Today they offer various techniques of asanas performance, but not all of them are “equally beneficial” for one’s organism. Only asanas performed in mode of physiological stretching result in laxation of tense muscles and induce tonus of muscles that are over-relaxed. In addition this effect is complemented with regulation of inner organs work. What goes on within one’s body during such practice and what is that proper manner of asanas performance that facilitates perfect realization of therapeutic effect?
Let us figure out.
We shall start from study of muscles system anatomy.
Human body contains ca. 600 muscles, each of them staying in connective tissue compartment called fascia. Fasciae proceed into tendons that fasten major part of muscles to bones.
Each muscle is a sum of muscular fibers – myofibrils that are sets of muscular cells. Each fibril has its own connective tissue capping – sarcolemma. Between myofibrils inside each muscle there are thin interlayers of loose cellular tissue that numerous vessels and nerves come through.
All muscular fibers are divided into extrafusal and intrafusal ones. Extrafusal fibers build up main muscle structure and come as its “contractive working elements”. Intrafusal fibers (Lat. intra – inner, and fusus – spindle) are made of atypical muscular cells: they are less and shorter than typical muscular fibers, in their histologic structure they are closer to embryonic muscular tissue and they are cross-striated (this being feature of fiber contractility) only along periphery. These fibers are contained in extensible connective tissue capsules. A capsule, nerve endings and intrafusal muscular fibers (up to 10-12 in one capsule) make up muscular receptor – the neuromuscular spindle.
It is interesting to study the structure of the neuromuscular spindle: its intrafusal muscular fibers are innervated by 3 (!) types of nerve filaments. Two of them are of afferent type (primary and secondary filaments, type Ia), they transmit information about muscle state to the superposed sections of nervous system, and the third one is of efferent character (type II), it carries responsive signal to muscular receptor (lat. afferens —bringing in and efferens — taking out). Afferent fibers form endings of two types close to the spindle central part, them being primary fibers – annulospiral endings, and secondary fibers – the grapelike nerve endings (located to both sides from the annulospiral ones). Efferent fibers form endings (gamma-receptors) along peripheral area of muscular fibers, in the area of their cross-striation.
Unlike intrafusal fibers, the extrafusal ones have only one type of nerve endings that build up neuromuscular junctions (Doyere’s eminences) which excitement causes contraction of a muscle.
Here we should mention that muscular spindles are aligned in parallel with extrafusal muscular fibers that they are situated between, and they register the rate and speed of muscular fibers stretching unlike another type of receptors – the tendomuscular spindles (or Golgi apparatuses) that are located at the places of muscle to tendon transition, perpendicular to the tissue direction. Golgi receptors are sentient receptors that register the rate of muscular tissue contraction.
Let us now study out the way this unique mechanism works during performance of asanas in the mode of physiological stretching. At the first stage, when one enters asana, there happens primary stretch of muscular connective tissue apparatus (that of tendon, fascia, cells sarcolemma, neuromuscular spindle capsule). This very part of the muscle, being a kind of specific “myoskeleton”, is the least stretchable and serves as a barrier against intensive stretching of muscular tissue. One may feel this in form of “inability to make a profound stretching” while entering asana; it shall cease in 10-15 seconds letting one “complete the stretching”. If at this stage one shall proceed with fast and excessive stretching, showing “the character” and overcoming the resistance of connective tissue, this shall cause the simplest tendon reflex that withdraws at the level of spinal cord and comes as emergency response to the irritator; the muscle shall stretch out abruptly, and this shall be followed by abrupt contraction. The purpose of this reflex is to prevent the tendon tear in the fastest and most efficient way, without a second thought (i.e. without data transmission to the cerebrum). In this case subtle mechanisms of muscular tissue elaboration that asana is meant for shall be substituted by the mechanism that in terms of phylogeny is older and more simple, while major part of muscles tissue and receptors shall remain unengaged.
Thus, from the point of physiology it shall be wiser to enter asana slowly, with 10-15 seconds’ fixation in position of utmost stretching (without overcoming resistance from part of connective tissues) and then proceed with stretching that shall now engage muscular fibers directly.
Further moderate stretching that is performed in asana shall cause stretching of extrafusal muscular fibers and even bigger tension of intrafusal fibers; this is followed by ramification of coils of annulospiral nerve endings and emergence of receptor potential in primary nerve-fibril. Precipitated excitement is transmitted further through nerve-fibril to the body of spinal cord receptor neuron, and from there by reflex arch it goes to the motor neuron; after this it proceeds to the Doyere’s eminence from where the excitement is transmitted to the muscle making it contract.
At this stage we should emphasize that further stretching should be done without great difficulty – only in case stretching is moderate the stretching intensity shall increase. In case of “overstretching” no muscular contraction shall emerge. The matter is that at its micro-level muscular tissue consists of actin and myosin thin filaments that are situated at a certain distance from one another. Emerged excitement activates specific chemical processes in muscular tissue and thin filaments start moving from one another. All other conditions being equal, contraction intensity shall depend upon the rate of actin thin filaments overlapping by the myosin ones and respectively upon number of bridges that have formed between them; in case of overstretching the rate of actin and myosin thin filaments ramification disables generation of bridges.
So, let us proceed. We have slowly entered asana with maximum stretching and have stayed so for 10-15 seconds up to moment of “flexibility reserve” emergence. Then we have proceeded with further stretching thus causing muscle contraction. In this position it would be wise to preserve this state of stretching further on with one’s focusing on laxation of muscles that do not participate in posture maintenance, so it would strain the “required” working muscles. What thus happens? It causes engagement of cerebrum structures, and we remember that it is not possible in case the action is performed in quick tempo. The number of neurons involved being great, the reflex arch becomes complex and the process proceeds with higher rate of consciousness. It is only owing to conscious concentration that correct laxation of “extra” muscles shall be possible; it shall also cause interruption of pathologic stereotypes and all work shall be passed onto muscles that should maintain the posture previously taken by the body. It is very important since, first of all, it launches work of maximum number of muscular fibers, and thus major part of the muscle shall be involved into work (here we should say that in case a movement is of short-term character, in case we stay in asana for a short time, it is not the whole muscle that is engaged into working process but only some part of its fibers). Second, by this moment grapelike receptors of secondary nerve fibrils start working in a more active mode, and it results in more intensive contraction of myofibrils that have been already working. Thus muscles shall contract in a more profound way (* a number of authors suppose that annulospiral endings react mostly upon the speed of muscle contraction, while grapelike endings react upon length modification. In any case, should localized contraction be slow, the receptive field shall be engaged to its maximum).
In order to attain even greater “engagement” of the muscle one should perform another slight further stretching in 10-20 seconds; this shall increase impulsation from muscular receptors and the rate of spinal cord motor neuron excitement. And only accumulation of certain level of strain in spinal cord motor neurons shall “launch” gamma-receptors at the periphery of muscular fibers, in the area of their cross-striation. Peripheral part of intrafusal fiber shall contract, thus evoking strain of the central part; it increases frequency of impulsation that comes from muscular receptors, and thus causes even greater contraction of the muscle. Besides, the process shall also involve muscular fibers that have been previously unengaged.
In this way, intensive contraction of a muscle and its profound working-through in asana is possible in case of slow, conscious stretching of muscles that are required for maintaining this posture in the mode of successive further stretchings with 10-20 seconds’ intervals between them.
As a rule, after 3-4 further stretchings (40-80 seconds) a rather intensive muscle contraction shall emerge; it shall cause stretching of Golgi tendon organs’ endings, and cumulated strain (these receptors are characterized by high sensitivity threshold) shall evoke a group of impulses flowing towards spinal cord motor neuron thus causing its suppression. The muscle enters the phase of profound laxation. In physiology this phenomenon was given the title of the “jack-knife effect”. By this the motor neuron of antagonistic muscle shall be excited by reflex, this being reason of slight contraction that happens with it (stimulation of antagonists muscle tonus). Muscular tonus of one functional group shall come to alignment. (Here we should note that today the role of tendon receptors in the mechanism of jack-knife phenomenon emergence is disputable, though the fact of the mechanism existence has been acknowledged).
Having attained the above-described result, one should fix oneself in asana without further stretching for 10-20 seconds for more profound setting of intermuscular equilibrium and conscious memorization of “proper muscular tonus”. (One should try to deliberately maintain this tonus while coming out from asana). After this one may start slow coming-out and for some time fix oneself in original position for normalization of pressure measurements.
At the end of the article we would like to emphasize the peculiar character of physiological stretching method that enables engagement of gamma-system. It is this system’s excessive activation that leads to emergence of muscular tonus modifications in one’s organism, for instance, muscular rigor contraction and muscular rigidity that has been recently denominated by the term “gamma-rigidity”. Excessive activation is often stipulated by disruption of cerebrum sections’ processes that are connected to emotional compound element of human behaviour and that control functioning of the internals. In case of asanas deliberate, directed effect upon gamma-system sections but for regulation of muscular tonus one may also expect function normalization of the body inner parts and its systems by means of reflective muscular-visceral connections ( The reflex mechanism of asanas has been described in the book YOGA. Physiology, Psychosomatics, Bioenergetics by A. Safronov)
So here is the method of physiological stretching in asanas.
1. Asana slow entering.
2. Initial stretching in asana that is performed up to the moment of “flexibility reserve” emergence (10-15 seconds). (*the time given refers to preliminary warmed-up muscle).
3. A series of additional further stretchings (10-20 seconds each), 3-4 stages in average.
4. Further stretchings are done in slow mode with one’s focusing upon contracting only the muscles that participate in posture maintenance. The rest of muscles are held in conscious laxation.
5. Upon onset of muscular discharge we stay in asana for another 10-20 seconds and then proceed to our original position.
Regular practice of properly selected set of asanas shall result in:
1. Regulation of skeleton muscles’ tonus and harmonization of intermuscular relations.
2. Normalization of blood-vascular and nervous system as a consequence of their compound elements’ deliverance from pressure of over-tense muscles.
3. Harmonization of one’s body posture that but for feeling good makes one look more attractive.
4. Normalization of body inner parts and systems work.
In addition to this one’s becoming aware of muscular stereotypes serves as a prerequisite for their change by means of djnana- and raja-yoga techniques. In this term the practice of hatha-yoga comes as a step to further stages of one’s self-cognition and self-development.
We wish you a successful and fruitful practice!
This post is also available in: Russian