Interpretation Of Biomechanical Data To A Gymnastics Coach

AbstractSeveral trials of many different gymnastics skills on various pieces of apparatus werefilmed and the results were studied with the coach. The time to accomplish the entire skillas well as the time for each segment of the skill was important to the coach. He was alsointerested in angle of release or push -off and the path of the center of gravity. Lastly,graphs of velocities and accelerations of limb segments were revealing to the coach. Bio-mechanical analysis has helped him see why the performances were good; he is more interestedin working with the investigator in all the events in gymnastics through the medium ofcinematography.The sport of gymnastics is undergoing rapid development; gymnasts all over the world areaccomplishing increasingly difficult tricks in each event yearly. Although this is occur-ring at an alarming rate, actual biomechanical analysis of gymnastics skills is in its in- fancy. Because of the high risk involved in performing these tricks, teaching the underly-ing steps leading up to the trick is of paramount concern to the coach. Knowledge andunderstanding of biomechanical data based upon scientific principles is quickly becoming anasset to a good gymnastics coach.At the University of Oklahoma, the men's gymnastics team is composed of national andworld champions. Slow motion films at 48 or 64 frames per second were taken of many dif-ferent skills on various pieces of apparatus and analyzed. The biomechanical data obtainedfrom this analysis included temporal factors, the path of the center of gravity, linear andangular displacement and velocity.Initially, the coach was shown the skill in slow motion. The marked joint centers werepointed out to him. He was told to observe the relationship among the body segments andthen was asked if and how this helped him as a coach. He stated that the slow motion filmverified some of his coaching techniques but contradicted other points, now that he couldsee what was actually occurring. Observing several gymnasts perform the same skill helpedthe coach see minor differences in performances. Important aspects of the skill were dis-cussed including the angles of take -off, various styles of the tuck position and speed ofmovement. Most gymnastics coaches stand to the side of the performer or where the judgesmight be stationed to view routines so this coach was interested in the frontal aspect.This view gave him a different Perspective of the skill. On the rings, for example, thegymnast performing the iron cross had had a shoulder injury. It was apparent from thefrontal view that he was favoring the injured side because he was not totally symmetrical inhis performance.In addition to observing the actual skill, the coach was fascinated by the movements ofthe equipment of which he was not aware. The extraneous movements of the parallel bars whenthe gymnast released them for a trick was quite noticable. It was evident which gymnastused the flexibility and spring of the bars to his advantage as opposed to swinging in arhythm which is counter to the movement of the bars. The coach surmised that this bar vi-bration could be the cause of the fear which gymnasts experience in the developmental stagewhen performing tricks where they must release the bars and then regrasp them.The full -in back out is a double backward somersault with a full twist on the first flip.After observing the slow motion pictures, the coach compared the position of the shouldersat take -off of two subjects on a free body diagram and realized that the better gymnast hadhis shoulders over his hips whereas the lesser skilled gymnast had too much of a backward