The Foundations of Structurotherapy, by Nicolas de Lussy, physiotherapist

The increased accuracy of 3D anatomical models, seen through the prism of Francoise Mézières’ technique (18), has led us to look into collagen’s long-ignored but crucial role.


The Foundations of Structurothérapie, by Nicolas de Lussy, kinésithérapeute

Current theory does not take into account muscular swelling (15), so let us imagine the following hypothesis: the effectiveness of muscular action derives from the swelling of motor units, which separate the inextensible fibres of the muscle envelope by creating a tautness in the bone inserts (Diagram 1).

Widely accepted theory on the linear contraction of skeletal muscle fibres (5) asserts that all skeletal muscles function by shortening, and cannot work any other way (13, p 375), and that muscle fibre is made up of cells specialised for contraction (linear contraction in the case of skeletal muscles) (3, p 96). Hanson and Huxley’s theory of muscular contraction by the sliding of filaments, set forth in 1955 (11), suggests that muscular function is the result of traction created by the linear shortening of the actin/myosin motor units, connected to the muscle’s bone insertion by an elastic tendon(Diagram 2).

Our observation contradicts this theory. Let us look at the action of the forearm biceps. It is widely accepted that this muscle is responsible for the elbow’s frontal flexing. Yet, our examination has revealed incoherence in several aspects of this assertion (Diag 3).

  1. If the shoulder inserts are stable, the elbow insert traces a minimum trajectory of 5.82 cm, while the forearm bicep retracts by a maximum of 5 cm.

The insertion at the elbow traces a minimum trajectory of 5.82 cm, but the biceps ensemble can only retract a maximum of 5 cm. The 0.82 cm difference is not covered by the sliding of the biceps, which must also take on the motion of the shoulder insertions, which are considered fixed. (Diagram 3)

  1. For the hand to lift a 10 kg mass, the forearm biceps develop 1000N in their most efficient position, that is, with the upper arm alongside the body and the elbow flexed at 90° angle. The same weight can also be lifted by bending the elbow with the upper arm remaining flat on a table. But starting this movement requires a force of at least 5758 N. Our study suggests that it is impossible for the biceps’ additional force to derive merely from supple and passive muscle tissue (1) (Diagram 4).

  1. It is practically impossible to accurately measure the trajectory of an object pulled through an elastic (Diagram 5).

These three observations show flaws in the theory of linear contraction.

In nature, the use of pressure on a stable element to create the movement of a mobile element is a natural, simple and efficient action.

If we use a bow (6) as an analogy, the theory of pressure requires the following 3 elements (Diag 6).

1: a motor unit whose extensibility is proportionate to its visible contraction

2: inextensible fibres to transform the energy of the motion into traction, as in the case of a bow

3: a bone support capable of taking up the effort created by the pressure, as in the case of a pre-stressed beam



Let us verify the existence of these three elements:

  • Can a motor unit increase in volume?

Yes, because Professor Shannon Meadows observed a fibre stimulated under an optical microscope and saw that muscle tissue swelled when it shortened in length (17):

Yes, because motor units are made up of actin and myosin protein coils. They are arranged as a harmonious series of Z-shaped ribs and their accordion-like structure enables their extension in height (1) (Diagram 7).

Yes, because the arrangement of actin filaments in a hexagonal pattern around the myosin filaments enable them to be spread apart by the myosin’s radial motion (1).

  • Do inextensible fibres exist?

Yes, those of structural collagen (22), the most common of the 28 types of collagen present in the body. Structural collagen is made up of three spiralled threads forming an inextensible wire at least as strong as nylon. It is the source of muscle cell fusion in embryology and is present throughout the body. Collagen encases bones, joints and muscle in a coarse diamond mesh. It is the only rot-proof element of the body. This intact fibrous tissue has even been found in a mummy (4).

Thus, the tautness of this mesh gives cohesion to the ensemble. And changes within it allow joint movement (16)(Diagram 8).

    • Is bone structure able to take up transverse force

    Yes. Long bones are made up of structural collagen and calcium. Collagen forms a vertical thread in diaphysial tissue and a compact weave in epiphyseal tissue. Bones take 20 years to regenerate, the surface elements of the diaphysis moving inward. Bone is therefore mobile tissue (9, p191).

    Diaphysial collagen is coiled in inverse spirals that encase calcium, forming strands that are driven inwards in the diaphysis as they become thinner, but their extremities are immoveable in the epiphysis (as observed with silver needles (à verifier) and the cross-section of bones) (14). The diaphysis is curved and hollow in the centre, therefore the inward shift of these strands can only lead to an increase in the tautness of the coils and thus to the compression of calcium. The decrease in their diametre, from the outer surface toward the centre, confirms this and suggests that the most internal fibrous tissue is the most taut from the outset. This “pre-tautness” enables the absorption of changes in form due to transverse thrust (10).

The three observations above obey the mechanics of a bow:

  • A study of the movement of two parallel straps bearing a weight.

To illustrate this, let’s take two parallel straps whose upper ends are fastened together at a raised, fixed point, while their lower ends are attached to a weight. The weight is transferred by the fixed point’s reaction through the resistance of the straps’ fibrous structure.

A separation of the straps causes the weight to rise.

The rate of separation is rapid at the beginning, but it slows as the weight rises.

The force of the straps’ separation is nearly nil at the start, but it strengthens quickly as a result of the rising of the weight. (see ”Google graph of y=x/sqrt(1-x^2)” between 0 and 1).

Fig.10 : y=x/sqrt(1-x^2)

As we see, the rising of the weight, slow at the beginning, accelerates as the separation between the two straps grows (see ”Google graph of y=sqrt(sqrt(1-(1-x)^2))/(1-x)” between 0 and 1).

Fig.11: y=sqrt(sqrt(1-(1-x)^2))/(1-x)

    • Verification by the use of robotic arms

    Robotic arms equipped with pneumatic muscles created by Festo in 2012, like those of Raymond Monedi in 1986 and McKibben in 1957, recreate human motion through the shortening obtained by associating a proportional valve with a net of inextensible diamond mesh fibres (7) (12) (19) (20).

    True to the laws of physiology

    Muscle tissue contains three types of differentiated contractile fibrous tissue that function according to a systematic order of precedence (2). Let us take an archer’s movement as an analogy: the activation of fibres I, IIa and IIb obeys the same curve as that of the increase in force of an archer’s motion. This motion is composed of 3 phases: the first is the wide drawing of the bow, requiring little strength (fibre 1), then a more forceful stretching and aiming that requires additional strength and movement (fibre IIa) and finally, just before the arrow is released, a last brief and intense stretching to maximise the force of the shoot (fibre IIb).

    The hypothesis of transverse thrust is based on these initial observations, and is the first installment of a series that will soon appear in book form.

    It is also based on the idea that the motor unit is extensible, and not contractile, and that bone, tendon, muscle and joint each have a specific mechanical role defined by their intrinsic characteristics.

    Muscle motor units – much like an assembly line of gearshifts — produce a transverse thrust that collagen fibres transform into traction. Weight is taken up by the collagen mesh whose tautening increases the resistance of the weight-bearing tissue.

This hypothesis develops established knowledge to open a wider vision conducive to fresh bio-medical progress.


Bibliography :

[1] Bélanger M., 1999, “Guide d’anatomie fonctionnel”, ( pages sur “muscles squelettiques et travail musculaire/ relation angle/force(tension-longueur)” et “anatomie musculaire microscopique” )

[2] Costill D. et al., 2009, “La loi de Costill”, in “Physiologie du sport et de l’exercice”, éd. De Boeck, 580p.

[3] Cross P.C. et Mercer K.L., 1995, “Ultrastructure cellulaire et tissulaire. Approche fonctionnelle”, éd. De Boeck, 420p. (

[4] J. Dickson J. et al., 2006, « Qui était Ötzi, l’homme des glaces ? », in “Les maux de nos ancêtres”, Dossier « Pour la science », janvier-mars, p. 64-69.

[5] Duke T. et Julicher F., 2000, “Les protéines motrices : la main-d’œuvre de la cellule”, in “Images de la Physique”,

[6] Éric J., 2008, “Travail de l’arc, dynamique (simple) d’une flèche en phase de propulsion”,

[7] Entreprise Festo, 2007, “Les développements de robots pneumatiques”,

[8] Fonssagrives J.-B., 1861, “Hygiène alimentaire des malades, des convalescents et des valétudinaires ou du régime envisagé comme moyen thérapeutique”, éd. Bailliére et fils, p.133

[9] Fort J.-A.”, 1887, “Anatomie descriptive et dissection”, éds. A. Delahaye et E. Lecrosnier, Paris, 768 p.

[10] Freyssinet E. et Séailles J., 1928, “Procédé de fabrication de pièces en béton armé”, Brevet d’invention du béton précontraint,

[11] Hanson J. et Huxley J.E., 1955, “The structural bases of contraction in striated muscle”, Symp. Soc. Exp. Biol., vol. 9: p.228-264.

[12]Holtzer J., 2012, “Le muscle pneumatique”,

[13] Karp G., 2004,”Biologie cellulaire & moléculaire”, éd. De Boeck, 852 p. (

[14] Larousse (dictionnaire), “Coupe d’un os et sa structure”,

[15] Leval R. et al., 2014, “Robot humanoïde”, projet de 3e année, EPF École d’ingénieur-e-s de Sceaux.

[16] Marine nationale, Les nœuds marins, 2011,

[17] Meadows S., “Skeletal Muscle Cell Contraction”, video enregistrée par le Roane State Community College,

[18] Mézières F., interview par la télévision canadienne,

[19] Monédi R., 1986, “Le muscle myonédique”, Brevets déposés sur la robotique souple, McKibben , 1957

[20] Peulot E., 2012, “Le muscle pneumatique”,

[21] Thiriet P., 2014, “Anatomie 3D”, Université Lyon 3,

[22] Wikipédia, “Le collagène”,ène