The cause of the muscular shortening

The cause of the muscular shortening by Maurichio Ronchi

The muscular fiber is composed from a sequence of parts which are contractive (elastic, represented as yellow ellipse) and the non-contractile parts (connective tissue). With a reference to the physical law of the deformation of the elastic bodies, it turns out that the contractive muscular fibers behave like elastic elements; consequently after deformation by compression (contraction) they can return to  their initial condition. On the contrary, the non-contractive components (such as connective tissues) behave like plastic materials, so if a deformation (compression) occurs with a force and for a sufficient time that exceeds the threshold of the elastic deformations, it will become permanently deformed, the connective tissue will remain shortened.

“As a matter of fact, a muscle with fibers of actin and myosin more closely connected, with a thickening of connective tissue, which becomes more fibrous, lead to an increase of passive resistance force with a decrease of elastic capacity and functional resistance of the muscle itself ”( U. Morelli ).

Here I will show you a simple and empirical example illustrating the above theory.

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The first picture is an example of a relaxed muscle , where the violet net represents a portion of densified and highly fibrous fascial tissue. The second picturesimulates the contraction of the muscle, which highlights the low elasticity of the fibrotic fascia, which cannot allow the physiological dimensional change of the muscular belly, and such deformation lead  against the natural biomechanic joint movement to which the muscle is connected.

Therefore this collagen and fiber thickening, are areas that need manual treatments in order to maintain a physiological elasticity/flexibility especially after a trauma-injury or an intensive/repetitive work/training cycle.