Friday, April 18, 2008

History of Biomechanics

It may appear the French Revolution, Charlie Chaplin, War, Wine and NASA have nothing in common but they do and it is called biomechanics. The term is used more and more in everyday language and has come to mean the study of normal human movement. Patho-mechanics is the technical term for abnormal movement but is often restricted to medical text. At the time of the French Revolution, people, especially poor people, started to matter. The traditional hospitals had been glorified brothels where literally people went to die, usually in great pain and distress. New and increased concerns for the proletariat however meant radical change in health care with the establishment of teaching hospitals. Clinical experts were available to teach as well as practice. In the La Gaze (the beginning of medical specialisation), medics referred to all body systems as biomechanics. Modern interpretation takes rather narrower meaning preferring biomechanics to mean human movement only, but originally this was a term used to describe a complete biological system. Throughout history many researchers have tried to analyse walking but it took to the introduction of cinematography before real insights were made. Even today the strides made in the early 20's and 30's have not yet been surpassed. With the invention of photography frame by frame analysis of walking allowed observation of detail not obvious to the naked eye. The two men most associated with the technique were Eadweard Muybridge and √Čtienne-Jules Marey and their works are still referred too. Frame by frame analysis helped researchers make special sense of the abnormal human locomotion which had enormous potential for orthopaedic surgery. Anthropometry i.e. the identification system based on physical measurements of the body was created by Alphonse Bertillon a French law enforcement officer. He believed criminals were an inferior species and had physical defects which could be identified by measurement. Not only did he develop the first scientific system police used to identify criminals but also introduced the mug shot and the systematisation of crime-scene photography. Bertillon was the first to include footprint analysis. At is height, anthropometry or Bertillonage as it was known was widely used by French police and in other European countries but it was eventually replaced by fingerprinting. Anthropometry continued to be used by scientists developing growth charts and clothing size systems, and eventually became in common use in sport science. By far the most celebrated person to see a pratical use for biomechanics was Sir Charlie Chaplin who regularly filmed scenes backwards, then to the amusement of millions would show the films unning forward at higher speeds. No one has knows why people find silly walks amusing but the do and made Charlie Chaplin a very rich man and household name. By the fifties, North Americans were conserned at the increasing numbers of wounded veterans returning from Korea then later the Vietnam War. Appalled at the apparent lack of research and development in the science of rehabilitation for amputees and those physically afflicted the public outcry put greater political pressures on the government to introduction of a national rehabilitation initiative. Coincidentally this occurred when North Americans were alarmed at Russian dominance for space exploration. Zillions of dollars were pored into the US aerospace industry and science education in general. During this period it is reported that on a plane flying to Seattle were two strangers, both on route to attend separate conferences. One was the director for new US Rehabilitation Research and Development Program, the other the NASA supremo. After a few cocktails and the ice broken, they started a casual conversion to pass away the travelling hours. After the introductions the aeronautical engineer rather boldly suggested,

"Do you know if we made aeroplanes like you make false knees then our planes would never get off the ground?”

"What do you mean?" came the puzzled reply".

"You chaps try to replace the knee with something that looks like a human knee whereas we design a plane to defy gravity using the laws of nature."

That was the beginning of a very long and fruitful relationship between the two men and was also the birth of biomedical engineering or modern biomechanics. They agreed to meet after their respective conferences in a city park and one brought a couple of bottles of wine and the other bread. The aeronautical engineer suggested an experiment that with each sip of wine the friends had they should feed the ducks a wine soaked piece of bread. After several bottles of wine, the aeronautical engineers suggested his companion stand and try to walk in a straight line. The effects of alcohol caused the rehab expert to stagger and when he returned to his seat the engineered observed, “Watch the ducks walk.” Despite consuming the same volume for size of alcohol as the men, the ducks continued to maintain a straight line walking.” He asked his friend to explain why the alcohol appeared to have no adverse effect on the duck’s gait. Once they had agreed there was no significant physiological reason it had to be something to do with the body’s centre of gravity i.e the lower the centre of gravity the greater stability. Imbalance through intoxication caused humans to stagger whereas the broadbase of the dase kept them stable throughout. From that keen observation the science of orthoses and prostheses changed to reflect Newtonian Physics and Momentum Physics with emphasis of three and four (time) dimensional analysis. Combined with cinematography, anthropometry, force and pressure analysis, modern biomechanics has been incorporated into sports science and forms a major part of preparing elite athletes for the Olympic Games. Today, biomechanical analysis helps commentators understand the intricacies of movement that are unseen by the naked eye and also assists sportwear designers to manufacture performance enhancing footwear and swim suits, the effects of which are so eagerly awaited by spectators in expectation of record breaking performances.

1 comment:

Murad Jayah said...

Such a well written article. In the middle of my paper and couldn't stop reading. Kudos.