POSSIBILITIES OF IMPLICIT MOTOR LEARNING IN LONG JUMP PE PERFORMANCE INVESTIGATED BIOMECHANICALLY

Abstract

Introduction: Many investigations, e.g., Hay/Nohara (1990) deal with the biomechanics and movement techniques of the long jump. Therefore we obtained information about the best performance and advice on how to achieve this goal. Two main strategies of motor learning are known in long jump training: The first is feedback training, where the athlete consciously tries to adapt his performance according to the ideal. The second aims at changes in movement patterns by special exercises and arrangements, e.g., takeoff (TO) at a lower position. In this situation, the long jump performance adapts to the situation without the athlete being aware of what he is really doing. Although this strategy is often used in long jump training, especially with novices, even the trainer doesn’t really know what the results of this training are. The aim of our study is to investigate the changes of long jump techniques of preparation for TO and TO under conditions of ‘unconscious’ practice. Methods: Three groups of students, each in one special training situation, practiced long jump performance in four training sessions. An additional group (no training) was taken as the control group. Two-dimensional kinematic data on the last three strides and TO were filmed before (pre-test) and after the training phase (post-test). The subject’s movement was described by the time courses of the main joint angles and angular velocities. The analysis of the time-normalized data followed a combination of several statistical methods according to Schöllhorn (1995). Cluster analysis was used to classify the results. Results: Clustering the trials by means of all variables, the analysis shows a separation by individuals at the most general level which is independent of pre- or posttest. The next step of cluster analysis classifies the long jump trials by pre- and post-test. Further subdivision of variables indicates different clusters following the changes in movement patterns under specific training arrangements. Conclusions: Due to the shortness of the analyzed movement, the results of the cluster analysis give information on implicit motor learning in long jump training under special arrangements. The subdivision of variables allows us to identify which parts of long jump performance are trained by the applied training arrangement. Further investigations are necessary to prove that the identified changes are individual and do not follow a universal ‘ideal technique’ in the long jump. References: Schöllhorn, W.I. (1995). Comparison of biomechanical movement patterns by means of orthogonal reference functions. Biomechanics in Sports XII. Budapest, 20-24. Hay, J.G., Nohara, H. (1990). Techniques Used By Elite Long Jumpers In Preparation For Takeoff. J. Biomechanics 23, 229-239.