Edited by Dr. Giovanni Chetta
It is good to teach the flexion technique to lift heavy weights while it is not useful in the case of light weights. Furthermore, this technique can cause problems in the presence of important myofascial contractures and / or retraction of the posterior chain (lumbar area in particular) as it involves the risk of the "triggering" of the myotatic reflex and of the potentially resulting muscle "block".
In the case of carrying a backpack, varying the flexion of the trunk at each step generates an "alternation of role between muscles and ligaments which can thus lead to greater resistance (Gracovetsky, 1986).In the same way, carrying heavy bags hung on one or both hands, it is more convenient a slight flexion of the trunk with its small oscillations with each step rather than the traditionally recommended posture (which involves greater lumbar lordosis and fixity of the trunk). These methods also take into account "another substantial characteristic of the connective tissue, namely its viscoelasticity.
Viscoelasticity of the fascia
We have seen that lifting heavy weights by putting the deep band under tension is the safest way to do it but it must also be done quickly; in fact, slowly it is possible to lift only ¼ of the weight that can be lifted at speed (Gracovetsky, 1988). This is due to the visco-elastic properties of the collagen fibers which determine an elongation of the fascia if kept under tension for a long time.
Due to its viscoelasticity, however, the band deforms under load in a short time, for this reason a continuous alternation of the structures subjected to stress is necessary. The forces capable of elongating the belt are greater the greater the state of tension already present (the more the belt is elongated the more difficult it will elongate further), in a non-linear manner (according to the studies of Kazarian, 1968, the response of collagen to the application of loads has at least two time constants: approx. 20 min and approx. 1/3 of a second). The limit not to be exceeded in order to avoid breaking the fibers of the band is 2/3 of the maximum elongation.
Posture and tensegrity
Dynamic balance
The search for the uniqueness of posture is a mistake as it ignores the fundamental property of the connective tissue that is viscoelasticity. We are not statues. by their functional oscillation. The myofascial-skeletal system is therefore an unstable structure but in continuous dynamic equilibrium. We are a redundant system, ie varying the internal weight distribution does not necessarily imply a change in posture; the control and the efficiency of all this is fundamental for the well-being of the spinal column. As we have seen on the periosteum there is the maximum concentration of stress sensors (interstitial receptors) that quickly carry the relative information (and not just those of pain ) to the brain. The dorsal-lumbar fascia is therefore more than a transmission force, without it there would be no efficient control of the muscles. The "enemy" is therefore the splitting of the fascia from the periosteum (which occurs beyond 2/3 of maximum elongation); when the fascia is damaged, rehabilitation is very difficult, the subject presents a functional biomechanical and coordination imbalance. they are well transmitted. As a result they move like people suffering from back pain caused by collagen damage (forced to increase muscle activity).
Function and structure
Function precedes and shapes the structure, postural coordination is more important than structure.
Reality Check: 76% of asymptomatic workers have a herniated disc
(Boos et al., 1995)
It is no coincidence that man is the cybernetic system par excellence: 97% of the motor fibers that run in the spinal cord are involved in the cybernetic process modality and only 3% are reserved for intentional activity (Galzigna, 1976). Cybernetics is the science of feed-back, the body must know moment by moment the environmental condition to be able to place itself instantly, appropriately for the purpose of carrying out the process. Sense can never be dissociated from motion: the "environment must be continuously felt and evaluated, hence the need for gravity, synaesthesia, proprioception." Being and functioning are inseparable "Morin. Reflection is the main road.
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 the world of life at the highest level is the specific movement of man, which represents the most complex natural process.
The traditional idea that man is distinguished by intellectual prerogatives has long been outdated and it is now established that they too recognize the first origin in the acquisition of the bipodal morpho-mechanical condition (the liberation of the hands is a corollary). The current human body is above all the consequence of the need to perform maximum effective walking on two feet in the gravitational field. According to this theory, man must be able to move with a minimum consumption of energy within a constant gravitational field, with the corollary that during the journey the various structures (muscles, bones, ligaments, tendons, etc.) are subjected to one minimal stress.
Other articles on "Posture and dynamic balance"
- Deep fascia biomechanics
- Extracellular matrix
- Collagen and elastin, collagen fibers in the extracellular matrix
- Fibronectin, Glucosaminoglycans and Proteoglycans
- Importance of the extracellular matrix in cellular equilibria
- Alterations of the extracellular matrix and pathologies
- Connective tissue and extracellular matrix
- Deep fascia - Connective tissue
- Fascial mechanoreceptors and myofibroblasts
- Tensegrity and helical motions
- Lower limbs and body movement
- Breech support and stomatognathic apparatus
- Clinical cases, postural alterations
- Clinical cases, posture
- Postural evaluation - Clinical case
- Bibliography - From the extracellular matrix to posture. Is the connective system our true Deus ex machina?
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