The Effect of Extended Practice on EMG, Kinematics and Accuracy in Dominant and Non-dominant Dart Throwing

The question of whether dominant and non-dominant limbs are controlled by the same motor program in throwing tasks has not been clearly established. Prior research has been limited by a number of factors, including evaluations based on a small number of trials. The present study evaluated subjects over a course of five days of dart throwing using both their dominant and non-dominant limb. The variables of assessment focused on were average velocity of the throw, the angle at release, accuracy and the magnitude of EMG co-contraction over practice. The non-dominant limb was found to be significantly less accurate (p = 0.001), less consistent (p < 0.001) and produced higher velocity throws (p = 0.001) than the dominant limb over a total of 447 practice trials per limb. Co-contraction between agonist and antagonist muscles over the course of practice was not found to change substantially. Thus, this study supported that dart throwing is controlled by the same motor program and that the changing of limb or muscle group selection for the task is simply a parameter change.