Scoliosis as a natural attitude - Idiopathic scoliosis: old and new concepts, clinical case

Edited by Dr. Giovanni Chetta

The specific motion of man

The specific motion of man can be defined as the set of dynamic, energetic and informative events that converge in the bipodal alternating gait (motion with progression) and in the standing position (motion without progression).
Of all the structures of the central nervous system, more than a quarter participate directly and more than half indirectly in the planning and execution of movements; therefore, man, with his 650 muscles and 206 bones, is primarily a "motor animal" .
In fact, man needs to move for his own survival and well-being. For this reason, locomotion is the activity that takes precedence over all others. In fact, in the world of life at the highest level is the specific movement of man, which represents the most complex natural process. they recognize the first origin in the acquisition of the bipodal morpho-mechanical condition; the liberation of the hands is a corollary of this (Paparella Treccia, 1988). The motor functions and the body, considered in many cultures as inferior entities and subordinate to cognitive activities and the mind, are instead at the origin of those abstract behaviors we are proud of, including the very language that forms our mind and our thoughts ( Oliviero, 2001). In the embryonic, fetal and early childhood phases, action precedes sensation: reflex movements are made and then they are perceived. It is from the proprioceptive reflexes that mental representations (engrams) are born that allow the birth of complex motor skills and of the same ideas. In critical moments (intense stress), the muscular system constitutes a high priority system: when activated, the others systems, such as those responsible for the perception of sensations, attention, cognitive activities, etc., are in a state of relative blockage, as this state is linked in the unconscious to the execution of actions important for survival, such as escape, the attack, the search for food, for a sexual partner, for the nest. Finally, today we know how much the simple walk in a natural habitat is a very powerful rebalancer of the two cerebral hemispheres.
The current human body is therefore above all the consequence of the need to perform a walk of maximum efficiency on two feet in the gravitational field on a naturally uneven ground. According to this theory, man must be able to move with a minimum consumption of energy at the " internal of a constant gravitational field, with the corollary that during the walk the various structures (muscles, bones, ligaments, tendons, etc.) are subjected to minimal stress.

In 1970 Farfan was the first to propose the idea that movement proceeds from the pelvis to the upper extremities, that is, that the walking forces start from the iliac crests to go to the upper extremities. In the 1980s Bogduk specified the anatomy of the soft tissues surrounding the spine and , in the 1990s, Vleeming clarified the pelvis-lower limb link. Finally, Gracovetsky demonstrated that the spine is the primary engine of motion, "the spine engine". This role of the spine is still evident in our "ancestors" fish and reptiles but a man whose lower limbs have been completely amputated is able to walk on the ischial tuberosities without significant alterations in gait, ie without interfering with the primary movement of the pelvis. This basically demonstrates two things:

The facets and intervertebral discs they do not prevent rotation but favor it; the vertebrae were not built for static structural stability. In fact, the lumbar lordosis together with the lateral flexion mechanically induces, through a mechanical torque system, a torsion of the vertebral column.
The role of lower limbs it is secondary to that of the spine. They alone are unable to rotate the pelvis to allow motion but they can amplify movement.

The lower limbs, in fact, derive from the evolutionary need to develop the speed of the motion of man. The greater power required for this purpose cannot derive from the muscles of the trunk, which for this purpose should have developed a mass which is impossible from the point of view of the human body. "footprint. Evolution therefore had to prepare additional muscles, placing them, both for functional and spatial reasons, outside the trunk, ie on the lower limbs. The first task of the lower limbs is therefore to provide the energy that allows us to move at high speeds. Thanks to them, intervertebral movements, rotations on the transverse plane in particular, can take advantage of the complementary contribution of the hamstring muscles (hamstring, semitendinosus and semimembranous) to which the spine is connected through specific and considerable anatomical myofascial chains:

sacrotuberous ligament-longissimus lumborum muscle (located on the sides of the spine)
sacrotuberous ligament and iliocostalis thoracis (in this way the right hamstring muscles control part of the left thoracic muscles and vice versa),
gluteus maximus muscles - opposite great dorsal muscles (which in turn controls the movement of the upper limbs).

All these hamstring-spinal cross connections form a pyramid that ensures strong mechanical integrity from the lower to the upper limbs. The fascia is therefore necessary to transmit this complement of force from the lower extremities to the upper ones for the specific motion of the "man. The" energy impulse goes up along the lower limbs "filtered" by them (ankle, knee and hip represent in this regard critical passages) so as to reach the vertebral column in the appropriate phase and amplitude. In this way the trunk can use this energy by rotating each vertebra and pelvis appropriately (Gracovetsky, 1987).

Thanks to the specific system of articular "gears" (coupled motion) integrated with that of myofascial transmissions, the "human spiral" is transferred from the transverse plane to the frontal plane and vice versa, thanks to the ""talus calcaneal" mortar, at the breech level, in the presence of an adequate coefficient of friction (without the latter, in fact, the breech winding is difficult).

At the same time ground or excessively soft soles are inappropriate as they excessively disperse the compressive impulse, deriving from the calcaneal impact during walking, which is essential for the execution and transmission of torsional forces at the spine and therefore at the pelvis (Snel et al. , 1983). The foot, in its role as an "antigravity base", first makes contact with the support surface, adapting to it by releasing it, then it stiffens, becoming a lever to "repel" the surface itself. then alternate the condition of relaxation with the condition of stiffening. The alternation of laxity-rigidity justifies the "analogy with the"variable pitch propeller
The foot is therefore not a system of arches or vaults, but also a very sophisticated helicoidal sensory-motor system (Paparella Treccia, 1978).

"The human foot is a" work of art and a masterpiece of engineering "
Michelangelo Buonarroti

The foot is a sensory-motor organ, a bridge between the system and the environment, consisting of a "variable pitch helix made up of 26 bones, 33 joints and 20 muscles that influences the whole body.

When the knee is in flexion, movements of the leg are possible both laterally (1-2 cm at the ankle) and in axial rotation (external rotation of 5 °). This is necessary to allow an optimal support of the foot in relation to the unevenness of the ground. In full extension, on the other hand, the knee, being subjected to important load forces, presents, in physiological conditions, a great stability; therefore a joint block occurs which solidarizes the tibia to the femur (Kapandji, 2002). Therefore, in the flexion condition, the knee is able to "filter" the rotations of the foot and leg while, when it is fully extended, these rotations are transferred integrally to the femur, influencing consequently the pelvic girdle (in particular, the coxo-femoral joint and the talus-scaphoid joint are similarly structured and correspondingly arranged).

The rotation of the femur on the transverse plane involves a mechanical push by the articular surface of the femoral neck on the acetabulum, the tensioning of certain ligaments of the hip and the displacement of the centers of gravity of the hemisomes (pressure centers). Thus, for example, an internal rotation of the femur can passively determine an "initial anteversion (anterior tilt) of the corresponding hemibacus and, following the tensioning of the posterior ligaments (ischio-femoral ligament) and the anterior displacement of the center of gravity of the" hemisome corresponding, a rotation of the pelvis that follows that of the femur. Conversely, an external rotation of the femur can induce retroversion of the ipsilateral hemibacin followed by a corresponding rotation of the pelvis due to tension of the powerful anterior ligaments (in particular the superior bundle of the ilio-femoral ligament, called the ileo-pretrochanteric, and the pubo-femoral) and posterior displacement of the center of gravity of the relative hemisome.

In the reference position the ligaments of the hip are moderately stretched.In the external rotation all the strong anterior ligaments are tense (the tension is maximum at the level of the horizontal bundles, ie the ileo-pretrochanteric ligament and the pubo-femoral ligament) while the posterior ones (ischio-femoral ligament) are relaxed. the reverse occurs, the ischio-femoral ligament is stretched while the anterior ligaments are released (Kapandji, 2002).

The rotation of the pelvis is directly reflected at the level of the lumbar spine. As mentioned, the ligamentous and bony structure of the vertebrae as well as the "energy converter" characteristics of the intervertebral disc mean that a "couple of forces" (coupledmotion) act on the spinal column. This corresponds to the primordial and primary need of the spine to rotate the pelvis in the act of locomotion (Gracovetsky, 1988). Therefore, the lateral flexion of the lumbar spine is physiologically always associated with a vertebral rotation and vice versa (White & Panjabi, 1978). rotation capacity of the lumbar spine (5 °, Kapandji 2002) "requires" the use of part of the back (able to rotate approx.30 °, Kapandji 2002), for example, when walking. However, in order for the gaze to always move towards the horizon at the level of the shoulders and the upper dorsal tract (from D8 upwards), a counter-rotation and an opposite lateral flexion (with respect to the lower spinal tract and pelvis) is required.

The scoliotic attitude of the spinal helix as well as that of the flat foot (unwound breech helix) and hollow foot (wound breech helix) therefore represent transient physiological phenomena connected to each other and become pathological only when they manifest themselves in a stable manner.

The ratio between rotations in the transverse and frontal plane tends to the golden number of golden section, as well as the length ratio between various skeletal parts (e.g. hindfoot / forefoot length).

'The specific motion of man, one of the most admirable processes in nature, stands on the swirling pillars, custodians of the golden number, in themselves and in reciprocal relationships "(Paparella Treccia, 1988).

Using the gravitational field as a temporary reserve warehouse, the specific motion of man is of maximum energy efficiency: at each step, during the ascent of the center of gravity (deceleration phase), kinetic energy is stored in the form of potential energy for then be subsequently transformed back into kinetic energy during the descent of the center of gravity, accelerating the body forward and raising the center of gravity.

The increase in potential energy corresponds to a decrease in kinetic energy and vice versa. In other words, the muscular factor is not asked to cope with the periodic rise of the center of gravity but to control the contribution of the environment by modulating the ratio instantaneous between potential energy and kinetic energy, containing it within the limits of building specific motion. Since this task is delegated to the red (aerobic) muscle fibers, it results in low energy consumption (Cavagna, 1973): a subject weighing 70 kg in a walk in plan of 4 km sustains an energetic expense covered by the ingestion of 35 gr of sugar (Margaria, 1975). For this reason, man can be a tireless walker unlike quadrupeds whose motion with bent joints requires a much greater expenditure of internal energy (Basmajian, 1971).

Praise to the propeller

Gravity, in the long path of morphogenesis, models helical shapes which in motion take on the meaning of constraint, determining the helical trajectories. It is therefore the same gravity that over long times (morphogenesis) shapes those forms which in the course of motion (short times) assume the meaning of constraint. The helical trajectories introduced in the morphogenetic motions of the gravitational field with the contribution of intra-tissue constraints converge genesis of the forms (femur, tibia, talus, etc. up to the DNA have a helical shape).

Forms in nature are nothing more than plasticized swirling motions. The helicity of the motion trajectories cannot fail to be echoed by the helicity of the forms whose high content in symmetry propitiates structural stability (Paparella Treccia, 1988). In fact, evolution has chosen helical configurations as in motion they evolve while maintaining dynamic stability (angular momentum), energy (more kinetic potential) and information (topology). Stability, understood as resistance to perturbations, represents the goal that nature pursues anyway and everywhere The propellers are curves that grow without changing shape, their prerogatives of repetition and therefore of stability make them the expressions par excellence of the geometry that underlies natural motions.

' If a figure has been chosen by God as the dynamic foundation of his immanence in the forms, well this figure is the helix "(Goethe)

There force of gravity, both from a functional and structural point of view, it should not therefore be seen as an enemy; without it man could not exist.