The impact of practice constraints on the emergence of movement variability and creativity in a boxing task

This study aimed to examine whether targeted manipulation of constraints to induce broad search during practice of a boxing task leads to increases in movement variability and creativity. Thirty-four participants were randomly assigned to one of three groups to practice striking a boxing bag: different distances (N = 12), single distance (N = 12), no practice (control) (N = 10). The different distances group practiced hitting the bag from different distances with the aim to destabilize current movement patterns and invite a relatively broad search for alternative movement patterns, while the single distance group practiced hitting the bag at a single fixed distance at different positions at a semicircle surrounding the bag to induce a relatively narrow search to optimize current stable movement patterns. All groups completed a pre-test and retention diverging boxing test, striking a boxing bag in as many ways as possible, with three days of practice in between for the two intervention groups. The no practice group only performed in the two tests. Movement patterns were categorized as combinations of the limb used, the direction of the movement and the part of fist or foot that contacted. Movement variability was defined as the total number of distinct movement patterns (i.e., diversity) and the entropy within the movement patterns (i.e., evenness of their distribution), while movement creativity was defined as movement patterns that were both original and effective. The different distance group showed no significant increases in diversity and evenness but did show a significant increase in movement creativity. By contrast, the same distance and control groups neither showed significant increases in diversity and evenness, nor in creativity. These findings highlight that fostering movement creativity is supported by task constraint manipulations that encourage broader search space, and that this is only loosely associated with increases in movement variability.