History of Biomechanics & Kinesiology

[Guest guest]

Here are some extracts from an excellent summary of the history of

biomechanics and kinesiology, together with some of my remarks on various

sections. It is most interesting to see that some rather old myths and

beliefs are still being proliferated despite their being either questioned or

abandoned many decades ago. It seems as if some of our current 'gurus' would

even have encountered some tough oppostion to their beliefs in those bygone

times!

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History of Biomechanics and Kinesiology

A.

<http://www.usd.edu/~jarichar/HIST.html>

The history of this science goes back to its definitional beginning.

Kinesiology is a combination of the Greek for 'to move' (kinein) and 'logos'

(discourse). Kinesiologists - those who discourse on movement - in effect

combine anatomy, the science of structure of the body, with physiology, the

science of function of the body, to produce kinesiology, the science of

movement of the body.

It is usually accepted that Aristotle (384-322 BC) is the ''Father of

Kinesiology " . His treatises, PARTS OF ANIMALS, MOVEMENT OF ANIMALS, and

PROGRESSION OF ANIMALS, described the actions of the muscles and subjected

them to geometric analysis for the first time. He first to analyzed and

described walking, in which rotatory motion is transformed into translatory

motion. Further he discussed of the problems of pushing a boat under various

conditions was, in essence, a precursor of Newton's three laws of motion......

Archimedes (287-212 BC), another Greek, determined hydrostatic principles

governing floating bodies that are still accepted as swimming. In addition,

Heath (1972) suggests that his inquiries included the laws of leverage and

determining the center of gravity and the foundation of theoretical mechanics.

Galen (131-201 AD) a Roman citizen who tended the Pergamum's gladiators in

Asia Minor and is considered to have been the first team physician in

history. He used number to describe muscles. His essay DE MOTU MUSCULORUM

distinguished between motor and sensory nerves, agonist and antagonist

muscles, described tonus, and introduced terms such as diarthrosis and

synarthrosis. He taught that muscular contraction resulted from the passage

of " animal spirits " from the brain through the nerves to the muscles. Snook

(1978) suggested that some writers consider his treatise the first textbook

on kinesiology, and he has been termed " the father of sports medicine. "

Kinesiology and anatomy lay untouched from the mystical studies of Galen

until the 15th century when Leonardo da Vinci (1452-1519) advanced them

another step. This artist, engineer, and scientist, da Vinci, was

particularly interested in the structure of the human body as it relates to

performance, center of gravity and the balance and center of resistance. He

used letter to identify muscles and nerves in the human body that he

retrieved from grave yards in the middle of the night. He described the

mechanics of the body during standing, walking up and downhill, rising from a

sitting position, jumping, and human gait. To demonstrate the progressive

action and interaction of various muscles during movement, he suggested that

cords be attached to a skeleton at the points of origin and insertion of the

muscles. For more information go to Leonardo da Vinci

Galileo, the father of parabolic mathematics, also proved that the flight

(trajectory) of a projectile through a non-resistant medium is a parabola.

His work gave impetus to the study of mechanical events in mathematical

terms, which in turn provided a basis for the emergence of kinesiology as a

science.

The Italian Jesuit Francesco Grimaldi was the first to report hearing

sounds made by contracting muscles. Although his book, Physicomatheis de

Itlmine, was published in 1663, 2 years after his death, techniques for

studying these sounds were not available until 300 years later. In the last

few years, the invention of the electronic stethoscope and computer analyses

have made research in this field feasible. Oster has shown that the amplitude

of muscle sound is directly proportionate to the weight used to maintain a

constant contraction. These sounds appear to originate from the vibration of

single muscle fibers, particularly the fast-twitch fibers. In the future it

may be possible to use such sounds to determine which muscles are active in a

given movement and how hard each is working.(Oster, 1984).

[Mel Siff: Some of this work was reported in Scientific American in the

early 1980s and about the same time I used equipment from our Linguistics

Department and ultrasonic apparatus from the Obstetrics Dept to analyse

muscle action and joint sounds, for example in cases of chondromalacia

patellae.]

The circulation of the blood through the. body was first demonstrated by

Harvey (1578-1657), although he erroneously attributed to the heart

the function of recharging the blood with heat and " vital spirit. " (Harvey,

1959). Subsequently, Niels Stensen (1648-1686) made the then-sensational

declaration that the heart was merely a muscle, not the seat of " natural

warmth, " nor of " vital spirit. " This has been acclaimed as the greatest

advance in our knowledge of the circulatory system since Harvey's discovery

(, 1914). Three years later, Stensen, who has been credited with laying

the foundation of muscular mechanics, wrote Elementorum Myologiae Specium, an

" epoch-making " book on muscular function. In this book he asserted that a

muscle is essentially a collection of motor fibres; that in composition the

centre of a muscle differs from the ends (tendons) and is the only part that

contracts. Contraction of a muscle, wrote Stensen, is merely the shortening

of its individual fibers and is not produced by an increase or loss of

substance. (Ralton, 1926).

The word " orthopaedics " was coined by Nicolas Andry (1658-1742) from the

Greek roots " orthos, " meaning " straight, " and " pais, " meaning " child. " Andry

believed that skeletal deformities result from muscular imbalances during

childhood. In his treatise, ORTHOPEDICS or the ART OF PREVENTING AND

CORRECTING IN INFANTS DEFORMITIES OF THE BODY, originally published in 1741,

he defined the term " orthopedist " as a physician who prescribes corrective

exercise. (Andry, 1961). Although this is not the modern usage, Andy is

recognized as the creator of both the word and the science. His theories were

directly antecedent to the development of the Swedish system of gymnastics by

Per Henrik Ling (1776-1839).

In PRINCIPIA MATHEMATICA PHILOSOPHIAE NATURALIS, which is " perhaps the most

powerful and original piece of scientific reasoning ever published " (,

1949), Isaac Newton (1642-1727) laid the foundation of modern dynamics.

Particularly important to the future of kinesiology was his formulation of

the three laws of rest and movement, which express the relationships between

forces (interaction) and their effects:

I. Every body continues in its state of rest, or of uniform motion, in a

right line, unless it is compelled to change that state by forces impressed

upon it. (This is sometimes known as the Law of Inertia and was originally

proposed by Galileo in 1638.)

II. The change of motion is proportional to the motive force impressed and

made in the direction of the right line in which that force is impressed (Law

of Momentum).

III. To every action there is always opposed an equal reaction; or, the

mutual actions of two bodies upon each other are always equal and directed to

the contrary parts (Law of Interaction). (Newton, 1668).

The application of these laws to muscular function may be demonstrated by the

following analogy: While he is pivoting, a discus thrower must grasp the

discus firmly (to exert centripetal force) to prevent it from flying out of

his hand. In accordance with Newton's Third Law, the missile exerts an equal

and opposite reaction (centrifugal force). When his grip is released and

centripetal force no longer interacts with the discus, the implement flies

off in a straight line tangential to its former circular path. The distance

covered by the missile is proportional to the motive force imparted to it, in

accordance with the second law. The trajectory of the missile is affected by

gravity, wind velocity, and other forces tending to alter its state of

uniform motion, as predicted by the first law.

According to the Newtonian world view, changes of motion are considered as a

measure of the force that produces them. From this theory originated the idea

of measuring force by the product of mass and acceleration, a concept that

plays a fundamental role in kinetics. The greater the speed with which the

discus thrower whirls, the greater the acceleration applied to the mass of

the discus, the farther it will fly before gravity returns it to earth, and

the greater the force said to have been applied to the discus.

Newton is also credited with the first correct general statement of the

parallelogram of forces, based on his observation that a moving body affected

by two independent forces acting simultaneously moved along a diagonal equal

to the vector sum of the forces acting independently. By further analysis of

the laws of movement as applied by the discus thrower, it can be demonstrated

mathematically that the horizontal and vertical forces acting on the flying

discus are equal. The diagonal, which is equal to the vector sum of the

horizontal and vertical forces, is, therefore, 45 degrees , and the missile

should traverse the greatest distance when it travels at this angle.

In practice, of course, other factors of lift, drag, shape, gyroscopic

rotation, and so forth enter the situation, and it is possible that the most

effective angle of release may not always be the one that is the theoretical

optimum. Because two or more muscles may pull on a common point of insertion,

each at a different angle and with a different force, the resolution of

vectors of this type is a matter of considerable importance in the solution

of academic problems in kinesiology.

Within the recent past, physicists have demonstrated that Newton's theories

are valid only within the frame of reference in which they were conceived;

they do not apply to relationships between forces in the Einsteinian

[relativistic] world view. This discovery has little significance for the

kinesiologist, however, since he deals primarily with the forces of gross

[and relatively slow] muscular movement, and these are governed by the laws

of motion set forth by Newton.

In his studies of muscular contraction, Keill (1674-1719) calculated

the number of fibers in certain muscles, assumed that on contraction each

fiber became spherical and thus shortened, and from this deduced the amount

of tension developed by each fiber to lift a given weight. In AN ACCOUNT OF

ANIMAL SECRETION, THE AMOUNT OF BLOOD IN THE HUMAN BODY, AND MUSCULAR MOTION

(1708), Keill drew the erroneous conclusion that a muscle could not contract

to less than two thirds of its greatest length............

About 1740 physiologists became excited over the phenomena produced by

electrical stimulation of muscles. Haller summarized many of the early

experiments in his treatise on muscle irritability, and Whytt reported

clinical observations on a patient treated by electrotherapy. " Animal

electricity " was proposed as a substitute for the " animal spirits " that

earlier investigators had believed to be the activating force in muscular

movement.

During the summer of 1786, Luigi Galvani (1737 - 1798) studied the effects of

atmospheric electricity on dissected frog muscles. He observed that the

muscles of a frog sometimes contracted when touched by a scalpel, which led

him to the conclusion that there was " indwelling electricity which proceeded

along the nerve. " His Commentary on the Effects of Electricity on Muscular

Motion (1791) is probably the earliest explicit statement of the presence of

electrical potentials in nerve and muscle. Galvani is considered the father

of experimental neurology.

The study of animal electricity at once became the absorbing interest of the

physiological world. The greatest name among the early students of the

subject was Emil DuBois-Reymond (1818-1896), who laid the foundations of

modern electrophysiology.

Fascinated by the prospect of investigating muscular response produced by

electrical stimulation, Guillaume Amand Duchenne (1806 - 1875) set

out to classify the functions of individual muscles in relation to body

movements, although he recognized that isolated muscular action does not

exist in nature (Duchenne, 1959). His masterwork, PHYSIOLOGIE DES MOUVEMENTS,

appeared in 1865 and has been acclaimed " one of the greatest books of all

times. " (Jokl, 1956).

The modern concept of locomotion originated with the studies of Borelli;

however, very little was accomplished in this field prior to the publication

of DIE MECHANIK DER MENSCHLICHEN GERVERKZEUGE by the Webers in 1836. Their

treatise, which still stands as the classical work accomplished by purely

observational methods, firmly established the mechanism of muscular action on

a scientific basis. The Weber brothers, Ernst Heinrich (1795-1878), Wilhelm

Eduard (1804-1891), and Eduard Friedrick Wilhelm (1806-1871), believed that

the body was maintained in the erect position primarily by tension of the

ligaments, with little or no muscular exertion; that in walking or running

the forward motion of the limb is a pendulum-swing due to gravity; and that

walking is a movement of falling forward, arrested by the weight of the body

thrown on the limb as it is advanced forward. The Webers were the first to

investigate the reduction in the length of an individual muscle during

contraction and devoted much study to the role of bones as mechanical levers.

They were also the first to describe in chronological detail the movements of

the center of gravity........

On the basis of subsequent studies, Rudolf A. Fick (1886-1939) concluded that

the theory of " normalstellung " [normal posture or position] was not entirely

valid, as the recumbent position of a cadaver [or supine body] could not be

transferred to the vertical stance [or vice versa]. The degree of lumbar

lordosis is much less when the body is recumbent than when vertical; in the

latter position the center of gravity shifts forward considerably more than

Braune and Fischer assumed. Fick contended that no one posture is common for

people of all races and cultures. Modern anthropological investigations have

confirmed his opinion.

[MCS: Yet many 'authorities' today still teach the existence of highly

precise postures and neutral positions, together with the contention that

deviation from these 'normalstellungs' is what causes back pain and

dysfunction.]

The late nineteenth and early twentieth centuries were most productive of

physiological studies closely related to kinesiology. Adolf Eugen Fick (1829

- 1901) made important contributions to our knowledge of the mechanics of

muscular movement and energetics and introduced the terms " isometric " and

" isotonic. "

[MCS: It will be noted that these more than a century old terms, especially

'isotonic' (same tension... throughout a given movement), are often widely

applied and misunderstood. I have provided a detailed analysis of such terms

in the latest edition of " Supertraining " , explaining why they need to be

redefined or discarded in some situations]

The study of developmental mechanics was introduced by Wilhelm Roux (1850 -

1924), who stated that muscular hypertrophy develops only after a muscle is

forced to work intensively, a point of view that was later demonstrated

experimentally by Werner W. Siebert. " (Siedber, 1960). B. Morpurgo showed

that increased strength and hypertrophy are a result of an increase in the

diameter of the individual fibers of a muscle, not a result of an increase in

the number of fibers. The theory of progressive resistance exercise is based

principally on the studies of Morpurgo and Siebert (Steinhaus, 1955) but

Morpurgo's work is now being questioned.

L. Ranvier, about 1880, discovered the difference in the speeds of

contraction of red and white muscle. " The importance of his finding, " says

Granit, " is that it brought functional aspects into the focus of subsequent

research. " (Granit, 1970).......

[MCS: Some of you will recall the 'Nodes of Ranvier' which are found in

nerve fibres with fatty myelin sheaths and which enhance speed of electrical

conduction - well, Ranvier is the scientists responsible for this discovery]

F. Pauwels endeavored to demonstrate that muscles and ligaments act as

traction braces to reduce the magnitude of stress in the bones. His work was

criticized by F. Gaynor on the grounds that it was concerned only with

the stresses produced by loads placed on solid models shaped like bones. It

is possible that Wolff and Roux overemphasized the importance of mechanical

stresses without proper consideration for biological factors, which sometimes

exceed mechanical influences. Nevertheless, the theory of functional

adaptation to static stress remains a major hypothesis in the study of

skeletal development. J. H. (1957) has reviewed the material in the

field in an effort to construct a working hypothesis of the developmental and

functional relationships between the skeletal system and the neuromuscular

system.....

[MCS: Only recently the importance of bracing or tension elements in

physical structure and function has once again attracted interest in the form

of " tensegrity " (tension integrity) models of the joints, cells and other

bodily parts. Zenker and I discussed this issue several months ago.]

Interest in the subject of posture has declined among kinesiologists in the

United States during the last few years. In part, result decline may have

resulted from general acceptance of the dictum that " the physiological

benefits obtained from correction of common postural defects are mostly

imaginary " (Karpovich, 1965) in part, it may reflect the growing realization

that individual differences almost preclude valid generalizations.....

[MCS: Yet, certain 'experts' continue to make unsubstantiated claims about

correlations between health, pain and posture, especially concerning the

lumbar spine. One of our members, Barrett Dorko, has much information about

this mythology on his website at:

http://www.barrettdorko.com/desk.htm ]

According to the old psychological stimulus-response theory, the individual

is merely a communication channel between the input and the output. This view

fails to consider the contribution that the individual makes to the circuit.

In information theory it is recognized that through experience man

accumulates certain knowledge about his external environment, such as how an

object travels through space, and that the signals he receives from his

kinesthetic proprioceptors reveal to him how his body is responding to the

external presentation.

The individual is viewed as a limited-capacity channel, receiving and

responding to signals originating from internal sources as well as from the

external display. The relative importance of these two types of stimuli in

determining individual response appears to vary with practice and with the

ease or difficulty of the required response. One of the chief difficulties

confronting a performer is to separate one signal from another when they are

presented in rapid succession; perception of essential data is usually

obscured by competing signals that create " noise " on the input circuits. A

distinguishing characteristic of a skilled performer is his ability to

select, integrate, and respond only to those signals that are germane to the

situation; that is, in effect, to filter out signals that are mere noise. The

fact that stimuli may be correlated with each other may enhance the

difficulty for the performer........

[MCS: Yet there are those who maintain that simplistic drills on various

balancing devices or with apparatus like dumbbells or Pilates machines will

enhance complex motor abilities in entirely different settings.]

Since the appearance of the first edition of this book, the physiologically

motivated researchers largely have concerned themselves with the waveforms of

electrical activity in the nerves or brain or in the transmission properties

of nerve tissue. Psychologically oriented investigators have tended to search

for regular descriptions of the input-output of the human organisms. For

example, the neurogeometric theory holds that the receptor and the motor

systems are linked by space-time organized feedback mechanisms. These are

multidimensional. Motion is made up of posture, transport, manipulation, and

tremor movements, each controlled by its own sensory feedback. The brain

coordinates and regulates these feedbacks. Learning is thus based on the

brain's integration of the anatomic and physiologic relations between the

efferent and the afferent systems.

[MCS: Not many folk are familiar with the Neurogeometric Theory described and

studied by KU & MF in their textbook " Perception and Motion: An

Analysis of Space-Structured Behaviour " 1962, a book which I found to be

very useful in the early days of my own PhD research.]

Such new insights have rich import for kinesiology, but also introduce new

complications. The advanced student must now become accustomed to such

explanations as the suggestion that a smooth landing after a drop is due to

the release of a " complete preprogrammed open-loop sequence of neuromuscular

activity virtually unaided by myotatic feedback. " (Watt, 1966)

[MCS: What the last sentence is referring to is the phenomenon of

feedforward, virtual control, or 'open-loop' control taking place in the

brain before a motor action takes place. Feedback, or closed-loop control,

involves electrical information being fed back from the proprioceptors and

other senses to enable us to correct any ongoing action. Feedforward is

extremely important in all rapid and ballistic actions, for instance, in

throwing, hitting, kicking and catching actions. Both feedback and feedfor

ward are discussed in detail in Ch 8 of the latest " Supertraining " ]

While further use of the electromyograph (EMG) will continue to refine our

understanding of how the body functions, it seems unlikely that additional

major surprises will emerge from this technique. Probably, the next important

advances will result from computer simulation studies, particularly of

situations in which it would be impossible to use human subjects......

[MCS: This discussion rightly cautions against excessive reliance on the

EMG to analyse human movement, which can yield both useful and misleading

information.]

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Dr Mel C Siff

Denver, USA

Supertraining/