Non-dominant leg training improves the bilateral motor performance of soccer players

The aim of this experiment was to evaluate bilateral motor performance effects from training the non-dominant leg of competitive soccer players. The subjects were 39 soccer players, 15-20 years of age, performance-matched and randomly divided into a training group (n = 18) and a control group (n = 21) both belonging to the same team. Both groups were tested by using two standardised foot-tapping tests and three soccer-specific tests. The training intervention consisted of the experimental group participating in all parts of their soccer training except full play, using the non-dominant leg for 8 weeks. Statistical analyses for the soccer-specific tests revealed that the experimental group improved significantly as compared to the control group from the pre-test to the post-test period in their use of the trained non-dominant leg. Somewhat unexpectedly, the experimental group also improved significantly in the tests, which made use of the dominant side. The standardised foot-tapping tests revealed similar results. The results might be explained by improved generalised motor programmes, or from a Dynamic Systems Approach, indicating that the actual training relates to the handling of all the information available to the subject in the situation, and that the body self-organises the motor performance.