an ergonomic approach
By Dr. Giovanni Chetta
In fact, studies show that our organism, our postural and balance system, reacts to the flat ground by creating a lumbar hyperlordosis or with excessive arching in the lower back region. This lumbar hyperlordosis is present in almost the entire population and occurs mainly according to two models:
Model A: classic case of lumbar hyperlordosis. Excessive arching is along the entire lumbar spine which consequently corresponds to an excessive and wide opposite arching at the dorsal level (dorsal hyperkyphosis) and a straightening of the cervical spine (the latter is formed as a reaction to cervical hyperlordosis, which would be consequential to the first two curves, but which would not allow us to look at the horizon, a primary factor for the organism).
Model B: "disappearance of lumbar lordosis". Hyperlordosis is actually concentrated between the L5 and S1 vertebrae (last lumbar and first sacral) which consequently corresponds to an acute and excessive opposite arching at the dorsal level (dorsal hyperkyphosis) and, here too, a straightening of the cervical tract .
In both cases, there will normally be a posteriorization of the general body center of gravity (center of gravity) with respect to the ideal position (anterior to the third lumbar vertebra) and the resultant of the moments of force that weigh on the last lumbar vertebrae will predominantly present towards front
The main actor of this mechanism is the powerful and deep psoas muscle. This powerful flexor of the lower limbs (originates on the transverse processes, on the vertebral bodies and on the discs of the last thoracic vertebrae and of the lumbar vertebrae, passes under the inguinal ligament and, reuniting with the iliac muscle, which originates on the entire inner face of the wing iliac, inserts on the lesser femoral trochanter), depending on the prevalence of its recruited fibers may lead to: increased lumbar hyperlordosis (prevalence of lower fibers), anterior flexion of the trunk (prevalence of upper fibers), lateral flexion and rotation of the trunk and pelvis (prevalence of one psoas compared to the contralateral).
Lumbar hyperlordosis, which we have seen to be primary in postural alterations, is then compensated in various ways, based on various parameters, including certainly the genetic makeup, throughout the body. These compensations are nothing more than "forcing" that our brain, through the tonic postural system, is forced to ask muscles, tendons, ligaments, joint capsules, joints, nerves, organs, etc., in order to obtain a posture as much as possible. possible stable on land not congenial to us.
In the next chapter, the topic of "foot" will be explored, a fundamental aspect to understand how alterations in the whole body can arise from the ground.
Foot and posture
Il foot represents the fixed point on the ground on which the entire weight of the body rests. It is at the base of the antigravity control system (postural tonic system) which allows man to assume an upright posture and to move in space. The foot is both an effector and a receptor, i.e. it receives and executes commands (motor response), through the muscles, and, at the same time, it interacts with the rest of the body providing constant information coming from the cutaneous exteroceptors present on its sole and from the proprioceptors of its muscles, tendons and joints. The skin exteroceptors of the foot are highly sensitive (0,3 g) and represent the constant interface between the environment and the balance system. In fact, plantar information is the only one to derive from a fixed receptor in direct contact with the ground.
The foot, in the course ofevolution which has lasted for about 350 million years, due to the needs arising in the assumption of the upright position and bipodal walking, it has acquired, as a peculiar and differential human characteristic, the aptitude for stiffening or intersegmental cohesion. This breech cohesion is achieved by the capsule-ligament and aponeurotic formations to which are added the muscular formations with the functions of "active ligaments" and postural. The prehensile grasp is replaced by the antigravity grasp.
The foot is by far the most valid device that man possesses for controlling the environment subjected to the law of gravity. The genetic information gives the breech structure the underlying modeling. Environmental information flows into genetics which gradually memorize it over the generations, enhancing the genesis of antigravity prerogatives. The cultural factor, however, interferes with this development by altering the environmental information (for example by creating inadequate terrain and shoes) thus causing an evolutionary delay.
"The truth of the specific motion of man is hidden between the coils of a helix". R. Paparella Braid
The foot is a diaphragm interposed between external (environmental) forces and internal (muscular) forces, which meet, contrast and finally merge in it for the affirmation of the condition of equilibrium. The foot is a "spatial" structure that is capable of absorbing and distributing forces, relative to the infinite planes of space.
The structure of the foot is a unique masterpiece of architecture, or rather of biomechanics, with its 26 bones, 33 joints and 20 muscles. Functionally and structurally, it is possible to divide the foot into:
- rear foot formed by talus and calcaneus, central device "of the biomechanical control of gravity;
- forefoot formed by scaphoid, cuboid, 3 cuneiforms (also called midfoot; the midfoot plus the rear foot forms the tarsus), 5 metatarsal rays (metatarsal) and the phalanges of the 5 fingers; acts as an "adapter and reactor".
Other articles on 'Posture and Wellness - Foot and Posture'
- Posture and well-being - Importance of plantar support
- Posture and well-being - Incorrect Podalic Support
- Posture and well-being - Functional Scoliosis
- Posture and well-being - Organic dysfunctions of postural origin
- Posture and well-being - Postural examination and re-education
- Posture and well-being