Biomechanics History ( Biyomekanik Tarihi ) 2

1600's Rene Descartes

He published Tractus de Homine et de Formatione Fœtus in 1675. He stated “The body is a machine (the lever is a machine) made by the hand of God.” Descartes argued that all of animal physiology could be explained by mechanics (levers systems force analysis).

From his Meditations On First Philosophy, he stated “Archimedes, that he might transport the entire globe from the place it occupied to another, demanded only a point that was firm and immovable (fulcrum supporting force of effort and force of resistance); so, also, I shall be entitled to entertain the highest expectations, if I am fortunate enough to discover only one thing that is certain and indubitable.”

1600’s Giovanni Alfonso Borelli

Born in 1608, he is considered to be the Father of Biomechanics for his contributions to the field. The American Society of Biomechanics annually awards the scientist contributing the greatest achievement within the field with it's highest award, the Borelli Award.

Borelli’s knowledge of mechanics relative to human movement was restricted to the principles of levers and, as such, it appears to generate his accurate account of spinal muscle action. He worked in collaboration with Marcello Malpighi. Malpighi was a professor of theoretical medicine at the University of Pisa. Malpighi recalled “What progress I made in philosophizing stems from Borelli. Borelli states this about Malpighi “I worked hard dissecting living animals at his home and observing their parts to satisfy his keen curiosity”.

Marcello Malpighi (1628-1694)

Anatomist

Giovanni Alfonso Borelli (1608-1679)

Mathematician

Borelli applied these principles of Equilibrium of Rotation and Equilibrium of Translation to spinal biomechanical analysis. In his work De Motu Animalium, Borelli illustrates the first comprehensive accounts of force of effort provided by posterior spinal musculature in stabilizing a force of resistance. “If the spine of a stevedore is bent and supports a load of 120 pounds carried on the neck, the force exerted by Nature in the intervertebral disks and in the extensor muscles of the spine is equal to 25,585 pounds. At the fifth lumbar the muscular forces are equal to 413 pounds and the forces exerted by the disc are equal to 1239 pounds."

Click here to see an example from our courses that depicts the type of anatomical mathematical lever system analysis resisting a posterior force that Borelli would have used.

One of the greatest mechanical features noted of the body, as was shown by his analysis, was that the muscles act with short lever arms so the joint transmits a force that is a magnitude greater than the weight of the load. Borelli overturned older concepts of muscle action, which was that long lever arms allowed weak muscles to move heavy objects.

Equilibrium of Rotation

Archimedes demonstrated the lever arm for force was bigger than the arm used for resistance. It took little force or move a large resistance. For 1,800 years it is believed this is apparently the lever system used by the body to lift and move things.

Borelli showed the spine as he set it up, used a lever arm shorter than the resistance arm and the body actually used more force than the force of the weight of the object lifted or moved. This was against common thinking.

Borelli wrote “Galen also states that a tendon (muscle working on joint) is like a lever. He thinks that, consequently, a small force of the animal faculty (muscle effort) can pull and move heavy weights. This general opinion and surprisingly, to my knowledge, has been questioned by nobody. Who indeed would be stupid enough to look for a machine to move a very light weight with a great force i.e. use a machine or contrivance not to save forces but rather to spend forces? This seems strange and against commons sense, I agree, but I can convincingly demonstrate that this is what happens and given, permission, that the upholders of the opposite opinion have been mistaken.”

Dr Scherger`s demonstration of Borelli's Analysis

Borelli's Analysis

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Borelli demonstrated a Stevedore with a weight carried at the neck that each vertebral joint (individual lever system) in the lower back used an effective effort arm (created by the position of the muscle relative to the disc or fulcrum) that was shorter than the effective resistance arm (created by the position of the weight relative to the disc or fulcrum). This lever system requires more effort than the weight of resistance which ran against common thought. Why use an ineffective lever system?

In our courses we demonstrate many reasons why you should not use the spine in this manner.

1900’s

In their paper “ The History of Spinal Biomehanics” Abhay Sanan and Setti S. Rengachary. Neurosurgery 39(4): 657-668; discussion 668-669. 1996, they write that the type of lever systems analysis that Borelli performs disappears from science until 1935. Then Freidrich Pauwels demonstrates that forces into a hip joint constitute not only the weight of the upper trunk on the hip, but also the additional force of effort required to stabilize the upper trunk mass

Click here to see an example from our courses that depict the type of anatomical mathematical lever system analysis of the hip that Pauwels would have used.

Present History

We find current science is just beginning to return to the level that Borelli left it.

Examples:

1995:

A paper by K.P. Granata and W.S. Marras: The Influence of trunk muscle coactivity on dynamic spinal loads. Spine April 15; 20(8):913-919, 1995, finds that there must be another greater force at the fulcrum than just the weight of the trunk and it must come from the cocontraction of muscle. What they are speculating about is the force of effort and resultant force that Borelli did his work on 400 years ago.

2002

The authors of the following paper suggests there is a need to put the spinal joints into equilibrium. Serpil Acar, B. Grilli, S.L.: Distributed Body Weight over the Whole Spine for Improved Inference in Spine Modelling. Comput Methods Biomech Biomed Engin Feb; 5(1):81-90, 2002. In Borelli's work he demonstrates the spine in equilibrium. Working to the posterior, as Borelli demonstrated, there are no cocontractions that would supply active force of effort needed to put the spine into equilibrium and hence has already performed the work that these authors suggest needs to be done.

Note!! It is an extremely difficult anatomical mathematical lever system analysis to put the spine into equilibrium when resisting a force of resistance anterior to the spine. This is something neither Borelli nor anyone we are aware of has ever attempted. We demonstrated the procedures necessary to do this in our courses.

2003

John Scherger, D.C., applies the two principals (Equilibrium of Rotation and Equilibrium of Translation) to study and develop many concepts in human spinal posture.

An example of a major prevailing concept of thought at this time was that the upright S-shaped posture, first identified by da Vinci, was the best mechanical (mathematically efficient) position to exist upright in gravity.

Using the the principle of Equilibrium of Translation, Scherger demonstrates that the S-shaped spine upright under gravity is a complex and unstable position due to shear forces at the fulcrum (vertebral joint). He further develops mathematical necessity for stabilization for translational equilibrium.

Disc and facets are needed for complex Equilibrium of Translation stabilization.

The true stability and secret of the human S-shaped posture is revealed when it performs discretionary movements like sitting up supine or then upright moving forward against a resistance.

It is during movement that shearing is eliminated and the vertebral bodies are able to line up providing, at each fulcrum (vertebral joint) a simple mechanically efficient third force required for equilibrium of stabilization.

John Scherger submits his two courses to the National Strength and Conditioning Association. These courses underwent a peer review process for over a year before finally being accepted for continuing education credits.

Course #1

Spinal Fitness in Sports Medicine Series: Kinesiological Analysis of Human Spinal Development & Function in Earth's Gravity. Volume1.

Course #2

Spinal Fitness Series - Spinal Core Stability Training & Treatment: The Restoration & Preservation of Proper Structure & Function. Volume 2.

Both courses were peer reviewed by scientists from the National Strength and Conditioning Association.

In our courses we present many premises related to spinal biomechanics, spinal structure and function, spinal postural adaptation, spinal training and spinal treatment. In all of those premises we present mathematical proofs. In the preface to On Spirals Archimedes it is stated Archimedes was in the habit of sending statements of his latest theorems, but without proofs. Apparently some of those that had received his theorems claimed the results as their own. He then sent those individuals theorems, some of which were false “so that those who claim to discover everything, but produce no proofs of the same, may be confuted as having pretended to discover the impossible”.

A 1740 engraving of Archimedes planning the defenses of http://yasam-saglik-tip.blogspot.com/Syracuse. The Greek writing on his cap is (Archimedes the geometer).

In the tradition of Archimedes we have taken the time and effort necessary in our courses to provide anatomical mathematical proofs of all theorems.

Click here to see some examples of our theorems and the accompanied anatomical mathematical proofs.