The effects of amplification of error: a teaching strategy to improve motor pattern in weightlifting.

Aim: The aim of this study was to test the efficacy of an alternative teaching strategy called Method of Amplification of Error (MAE) and to compare the relative effectiveness of MAE to the traditional direct instruction method (DI) and to a no-feedback control (C). Developing methods aimed at improving motor skills in sports is a key factor in movement science. MAE assumes that amplifying the subject’s “main” error in a given motor skill would allow him to better understand what is not-to-be-done, thereby correcting motor errors (1). MAE employs movement as feedback and the feedback is maintained in the motor-perceptive language used by the subject’s own body.Method: 12 Regional and National weightlifters were assigned to one of 3 groups: DI feedback, MAE feedback and Control (C), without feedback. At the testing session each athlete performed 12 trials: 3 trials pre- training (T0), 6 trials feedback training and 3 trials post- training (T1). After a week the athletes performed retention test (T2). Each athlete performed the trials at 80% of the maximum weight lifted in the last competition with snatch technique. The feedback focused on the “main” error diagnosed as the incorrect position of the participant’s centre of mass projection during the first pull phase. Kinematic outcomes were recorded with a motion analysis system (VICON 1.5.1, 8 cameras, 250Hz), a dedicated software (VICON Workstation 5.2) was also used for digitalization and reconstruction of the marker positions. Nonparametric statistical analysis was performed using SPSS version 16.; the Mann-Whitney test was conducted to assess significant differences between groups at three levels: T0, T1 and T2. Statistical significance was set at P≤0.05.Results: At baseline (T0) kinematic outcomes were similar between groups (P>0.05). At T1 and T2 MAE showed a greater improvement (p<0.05) than DI and C for the horizontal displacement from start to first pull, from start position to catch and from most forward position to catch. Moreover, significant differences were observed at T2 for the horizontal displacement from start position to beginning second pull and the vertical travel range for MAE vs C, no significant differences vs DI, despite MAE showed a greater improvement than DI.Conclusion: This study focused on the use of different types of instruction (MAE vs DI) in improving the bar path kinematics of weightlifters. In previous studies horizontal displacement and the vertical travel range of the barbell have been chosen to characterize an effective technique. Results showed that MAE rapidly improves motor performance in comparison with DI. The different approach of MAE is that it is an unlearning task rather than a re-teaching one, in this way the subject deletes forever the error with a full transfer of learning.References. 1. Milanese C et al. (2008). “Amplification of error”: a rapidly effective method for motor performance improvement. The Sport Psychol, 22, 164-174.