Effect of A Dynamic Dual-Task Paradigm and Concussion History on Motor and Cognitive Performance

Prior to and following a concussion, athletes exhibit deficits in gait and cognitive performance between single-task (ST) and dual-task (DT) paradigms. Current motor tasks used in these divided attention paradigms may not be challenging enough to detect long-term changes following injury. PURPOSE: To determine if differences exist between ST and DT paradigms while performing a multi-directional gait task and Stroop test. METHODS: Fifteen male Big Ten Universities Rugby Conference athletes (20.53±1.60 yrs; 1.76±0.10 m; 86.11±9.47 kg) and 17 male American Collegiate Hockey Association athletes (20.06±1.75 yrs; 1.79±0.07 m; 85.96±10.25 kg) volunteered to participate. Two tasks were performed: 1) recite the color of the Stroop stimulus and 2) walk around a 3.05 x 3.05 m (10 x 10 ft.) box while maintaining forward gaze. Tasks were completed independently (ST) and concurrently (DT). Attempted responses were calculated as a percentage of attempted out of total possible responses (56 stimuli). The number of incorrect responses were calculated as ([incorrect responses / attempted responses]*100). Dual-task effect (DTE) was calculated as [(DT performance – ST performance) / DT performance * 100] for box distance and attempted responses. A paired samples t-test was performed to determine if differences in DTE existed between motor and cognitive performance. For all remaining outcome variables, 2 (paradigm) x 2 (concussion history) mixed-model ANOVAs were performed. Alpha level was set a priori at p<0.05. RESULTS: Participants walked a shorter distance under DT (10.49 m) compared to ST (11.66 m) (p<0.01). Athletes with a concussion history had a higher percentage of incorrect responses (2.73%) compared to those without a history of concussion (0.58%) (p=0.01). There were no differences in attempted responses between paradigms (p=0.38) or concussion history (p=0.66). DTE for box distance (-12.45%) and attempted responses (-3.80%) DTE were different (p=0.02). CONCLUSIONS: Motor and cognitive differences existed under a DT paradigm whereby DT elicited a greater degree of change from ST for motor performance than cognitive performance. Establishing a normative healthy DT baseline performance is warranted to better inform clinicians on appropriate return-to-play decisions following injury.