engleski

Toward objective skill levell estimation in sport gymnastics

Skill level in sport gymnastics is generally being estimated on the basis of complex heuristic criteria, including technical and aesthetic factors. Generally, the composition as a whole, no matter what type, is graded by one composite grade. Factors influencing the grade are ; the level of difficulty of the exercise and the composition. Additionally, so-called bonification is given for the virtuosity, originality and additional high level of difficulty (D). These are the reasons that the attempts to formalize the grading (and skill level estimation) preocesure as wllas make it more objective, are very difficult to provide and lack simple objective criteria (like for instance they are in athletics). A biomechanical approach toward objective skill level estimation in sport gymnastics, primarily of the technical value of the performance, is presented. The approach is based on processing of ground reaction force signals recorded during take-offs in backward somersault from the standing position and layout forward roll-two elements of technique being performed by any gymast of reasonable quality. (The importance of proper take-off in execution of various gymnastic elements of technique is generally recognized). Each element is performed three times, to assure repeatability of force signals recorded. Selected take-off force parameters ; maxima, times of duration, impulses and time derivates (gradientes) of the vertical component of force are extracted and compared against normative values. On such a basis, an estimation of 1. skill level of performance and 2. the degree of mechanical loading (stress) of the locomotor system is provided. In addition, a sample of typical force component signals in sagital plane is plotted, as a permanent record, to assist the coach in visual analysis and validation of take-off technique (as reflected in take-off force) of particular gymnast. (Further trend in force signal presentation will be in the form similar to the vectordiagram representation used for instance in 2 and 3). The protocol has been designed based on the statistical analysis of take-off force signals, and their predictive value estimation, obtained on the sample of women gymnasts, results of which will be presented elsewhere. Experimental findings have indicated that the above mentioned force signal parameters can serve as good formal predictors of the level of skill of performance, as well as of degree of tissue laoding-reaching sometimes extremely high values. While being relatively simple, the protocol aimes to provide a fast-feedback and efficient means of gymnast's skill level estimation, suited primarily to the selection purposes and to monitoring the process of skill development with training.

sport gymnastics ; take-off force

This work is a part of an investigation supported by the grant from Republic's Selfmenagement Interest Community of Physical Culture of Croatia