"Excerpt from the work of S.M. Starikov 'Modern Approaches to Spinal Elongation'
Scientific and empirical study 'Modern Approaches to Spinal Elongation' - winner of the Moscow Professional Union of Manual Therapists' 'Golden Vertebra' competition for the most significant study in the field of manual medicine in 2009.
S.M. Starikov, the principal specialist in medical gymnastics at the Ministry of Defense of the Russian Federation, Director of the Department of Physical Culture at the Institute of Continuing Medical Education of the Ministry of Defense of the Russian Federation, Doctor of Medicine, Colonel of the Medical Service.
Dynamic elongation of the spine
Today, one of the most promising avenues in research on the prevention and treatment of spinal diseases is elongation, which relieves the weight of the spine and tilting, ensuring the revitalization of muscle tone.
This type of combined action has long been known in manual therapy as one of the means of 'mobilization.' One of the founders of modern manual therapy, Karel Lewit, wrote in his fundamental work 'Manual Medicine': '...with rhythmic, repetitive, and passive movements overcoming tension at the end of the movement, on any segment of the spine, after 10-20 repetitions, blockage can be removed, even without resorting to manipulation. Mobilization is not only preparation but also an alternative to manipulation.' The essence of the intervention in this case is the reduction of muscle tone and the recovery of the range of motion in any motor segment, thanks to nonspecific oscillatory action on the muscles, which holds this segment in a defined position.
With the implementation of new care methods, including those using automated oscillatory movements, as well as specialized programs for passive elongation, there is an opportunity to dose procedures based on amplitude, frequency, intensity, and duration of intervention, as well as the choice of programs based on the individual characteristics of the patient.
In order to standardize terminology and systematize our representations on this physical action, we propose a term: dynamic elongation, which implies the simultaneous solicitation of the spine (or another motor segment) of two components: traction (or that which elongates along the main axis) and dynamic, making cyclic oscillations on adjacent planes. Further, arguments will be presented that demonstrate the interest of this approach.
The theoretical basis of the mechanism of dynamic elongation of the spine.
Several mechanical oscillatory movements take place simultaneously in the human body. Most of them are based on muscle contraction as well as the ability to change the elastic qualities of different tissues.
Examples of dynamic oscillations include:
Pulse (rhythmic contraction of cardiomyocytes, leading to heart contraction and undulating blood movement in vessels that change tone);
Breathing (periodic retraction of the diaphragm and all respiratory muscle tissues during the phases of inspiration and expiration);
Peristalsis (movements caused by the periodic retractions of the smooth muscle layer of the organs of the gastrointestinal tract as well as other hollow organs);
Craniosacral rhythm ('primary respiration' - micro-movements of the bones of the skull and the spine);
Walking (oscillatory movements of the pelvis, lower limbs, and the entire locomotor system during a person's movement in an upright position);
Chewing (retraction of the masticatory muscles and movements of the lower jaw);
Frictional rhythm (movements of the pelvis during sexual intercourse);
Blinking (periodic retraction of the muscles that lower the eyelid);
Other human movements that have a repetitive and cyclical nature.
However, any act of movement can be considered as a separate part (or set) of some oscillatory movements of different motor segments. The universally accepted physical characteristics of mechanical oscillations are:
Amplitude of movements - The distance from point '0' to the last, extreme point of mechanical movement in one direction (according to some sources, amplitude is the distance between the two extreme points).
Frequency of oscillations, expressed in the quantity of movements per unit of time.
Period of oscillations, directly related to frequency and equal to the time of a complete oscillatory cycle."
Crédit photo : AdobeStock.com
The peculiarity of mechanical oscillations lies in their ability to spread in different directions and to overlap, causing mutual amplification (up to the occurrence of a resonance phenomenon) or, on the contrary, leading to the 'damping' (reduction) of the amplitude of common oscillations. When considering the question of myofibrils as the main driving force of the organism's oscillatory movements, we can assume that the periodicity of the processes of excitation and refraining in the myocyte, leading to its contraction and subsequent relaxation, is directly related to the periodicity of the main movements of a human. As known, the nonspecific triggering impulse for the activation of any cell in a living organism (neuron, myocyte, secretory cell) is an action potential (AP). In an experiment, when stimulating a muscle with a single electrical impulse of supraliminal force (analogous to AP), a single muscle contraction of a specific form occurs. According to information from various authors, its overall duration is from 80 to 120 msec, and during this time, the following periods are distinguished: latent (hidden) contraction period (5-15 msec); shortening phase (40-50 msec); relaxation phase (40-50 msec).
The excitability of a muscle during different phases of contraction varies: thus, at the beginning of a latent period, it increases, then abruptly stops and reappears at a high level at the beginning of the contraction phase, then gradually decreases, and for the remaining time until the next latent period, it remains normal. A single muscle contraction resulting from experimentation is a prototype of the contraction of a separate motor unit (MU). During any muscle movement, a person simultaneously uses several MUs, which work in a specific order. Some part of the MUs, contracting and relaxing alternately, ensures muscle tone, and many MUs remain in a state of rest and only activate upon receiving a corresponding signal, after which synchronization of their work occurs, and a programmed movement takes place. The analysis of the entirety of mechanical oscillatory movements in the human body is quite complex due to their large number, multidirectionality, differences in amplitudes and cycles. Nevertheless, we can say that the dynamic balance of all oscillations is one of the foundations not only of the biomechanical stability of humans but also of the system of its homeostasis as a whole. The functional unit of a skeletal muscle is the motor unit (MU) - the entirety of muscle fibers that are innervated by the axons of a motor neuron. The innervation and contraction of fibers that are part of an MU occur simultaneously after the development of an action potential (AP) and the release of Ca2+ ions from the sarcoplasmic reticulum.
According to the 'Sliding Filament Theory' (cyclic interactions between filaments): myosin heads attach to actin molecules and form cross-bridges; myosin heads undergo a transformation that results in a force exerted on thin filaments. During the muscle tissue contraction process, the following transformations take place:
• Generation of the action potential (AP)
• Diffusion of the AP through T lymphocytes and the sarcoplasmic reticulum, increasing the intracellular concentration of Ca2+ ions.
• Interaction of Ca2+ ions with troponin, releasing active centers on thin filaments (actin).
• Interaction of thick filament heads (myosin) with thin filaments (actin), rotation of the thick filament head, and the development of elastic tension.
• Reciprocal sliding of thin and thick filaments, reduction in sarcomere size, increase in tension, or shortening of the muscle tissue.
According to various authors' assessments, the duration of a single muscle contraction is from 0.08 to 0.12 seconds. The continuous work of myofibrils at such a frequency has a fibrillation (palpitation) character. Given the rapid depletion of energy resources, this process cannot last long. The recovery period depends on the resynthesis process of a principal macroergic union of a living organism—ADENOSINE TRIPHOSPHORIC ACID (ATP). ATP reserves in a muscle cell are approximately 3-7 mmol/L. This amount is sufficient for only a few successive single muscle contractions. For long-term muscle work, there needs to be continuous ATP renewal to the required concentration level, which occurs every second. In doing so, physiological variations in ATP levels in muscle fibers provide the optimal rhythm for mechanical oscillations throughout the organism.
Uo level of the expected balance
Umax maximal level of ATP, Umin – the minimal level of ATP
Ua average level of ATP; t- 1sec
Given that the most commonly used means of accumulating energy is the oxidative phosphorylation process of ATP, we can assume that the physiological rhythm of muscle tissue depends on the speed of this biochemical reaction, which in turn is linked to oxygen consumption during tissue respiration. This, as we know, depends on blood circulation, driven by myocardial contractions and directly related to the function of external respiration. In this way, most of the muscular (motor) rhythms in a human are closely connected.
Surprisingly, we discover that by analyzing the historical reasons for humanity's adoption of a minimal whole unit of time – 1 second, we can assume that this choice stems from the natural biological rhythm of muscle tissue. That is, precisely the average physiological duration of a myofibril oscillation could be a prototype for the standard units of time measurement – 1 second. And a unit of frequency measurement adopted today – 1 hertz (1 hertz – one vibration per second) is precisely the frequency of physiological oscillations of muscle tissue.
As evidence of this hypothesis, the relative synchrony of the heartbeat (1 beat per second at rest) and the rhythm of ordinary human walking (1 step per second) can be considered. The phenomenon of walking can be seen as an example of a universal and synchronized oscillatory movement in which, under the control of the central nervous system, the work of distinct muscle groups is successively used. This leads to the alternating change of position in space of multifaceted motor segments, each with a certain weight, inertially affecting other segments. These, in turn, are in antiphase of the movement and with the same frequency, much like pendulums following their trajectory.
There is also a certain rhythm of relaxed breathing linked to the 1 hertz vibration frequency, precisely: inhalation - 1 sec, pause on inhalation (for gas exchange) - 1 sec, exhalation - 1 sec, pause for recovery after exhalation - 1 sec.
It is logical that the action of external mechanical oscillations on the human body with a frequency close to one vibration per second (1 hertz) has a high degree of synchrony with internal oscillations of muscle tissue. Therefore, the use of these oscillations for therapeutic purposes is justified.
In this way, the study of physiological oscillatory processes occurring in human muscle tissues is linked to a wide range of issues addressed at the current stage of manual therapy and medicine as a whole. Considering that anti-gravity muscles undergo constant static tension, which can lead to the development of numerous static-dynamic dysfunctions, the use of dynamic stretching on them, opposing the direction of gravity force, contributes to the most complete recovery of mobility, muscle tone, and overall motor activity.
We can consider the most physiological rhythm of dynamic oscillatory stretching to be close to the rhythm of energy metabolism (exchange) inside the muscle cell, which is approximately 1 per second. The use of oscillations with a frequency of 0.5 to 1 hertz contributes to the physiological relaxation of muscles, the restoration of their energy balance, and also acts not only on the anatomical structures of the spine but also stimulates microcirculation processes inside it. Furthermore, we observe synchronization of the main dynamic rhythms of the body: muscle contraction-stretching, walking rhythm, breathing, craniosacral rhythm, different organ rhythms, and so on.
Unlike static stretching, during dynamic stretching, there is a change in the traction vector, allowing for variable intensity on various muscle groups. The intensity of the effort can vary from a few hundred grams to several tens of kilograms. Due to the simultaneous action of oscillation and traction, the paravertebral muscles and "deep back muscles (short and long)" experience alternating tension and relaxation. This not only enhances the effect of the therapy pursued but also contributes to the active prevention of dorsopathies (back diseases). Dynamic stretching of the spine can be performed by a specialist (manually) or using specific equipment. The most effective way to achieve this is to use programmable equipment with the ability to adjust different stretching programs based on the individual characteristics of each patient (gender, age, weight, height, and others) that change in terms of amplitude, frequency, and traction force.