Variability, Decisions, And Movement... Does It Matter In Athletic Performance?

PURPOSE: The purpose of this study was to evaluate the effect of a neurocognitive load on movement variability and task outcome during a hop task. METHODS: Thirty six female (18 recreational and 18 D1) athletes performed 32 successful hopping trials (16 for each leg) in the absence (12 trials) and presence (20 trials) of a neurocognitive load provided by a light training system. A 12-camera marker-less motion analysis system, sampling at 85 Hz was used to record the hopping trials. For the contact phase of each hop of each subject, the coordinate histories of the center of mass of the trunk (tCOM) were grouped according to load condition, direction of hop, and hop number. The norm of the spanning set of the plus and minus 1 standard deviation curves was determined for each subject. Linear mixed models, with a random intercept to account for repeated trials, were used to compare load condition (load vs no load) and athletic level (recreational versus D1 athlete) and the interaction between load and athletic level for each task outcome. RESULTS: A statistically significant effect of load condition or athletic level was not present (p > .0.05) on the mean norm of the span set of the tCOM during the contact phase of hop 1 or hop 2. For D1 athletes, the mean norm of the span set of the tCOM for the contact phase of hop 1 for the load and no-load trials were, 0.122 (± .011) and 0.132 (± .011), respectively. For the recreational athletes, the mean norm of the span set of the tCOM for the contact phase of hop 1 for the load and no-load trials were 0.123 (± .011) and 0.136 (± .011), respectively. For the contact phase of hop 2, the mean norm of the span set of the tCOM for the D1 athletes for the load and no-load trials were 0.253 (± .019) and 0.232 (± .019), respectively. The mean norm of the span set of the load and no-load trials of the tCOM during the contact phase of hop 2 of the recreational athletes were 0.217 (± .019) and 0.232 (± .019), respectively. CONCLUSION: The variability of the tCOM does not appear to be affected by athletic level or neurocognitive load potentially indicating the tCOM is a key variable the neuromuscular system is attempting to control.