Our purpose was to examine running and walking gait biomechanics in recently concussed athletes and explore the effect of an added cognitive task on biomechanics. We recruited recently concussed collegiate athletes who completed two testing sessions: within 24-72 hours of full clearance and 1 week post-clearance. The participants’ biomechanics were analyzed under four conditions: (1) walking alone (single task, ST), (2) walking while simultaneously completing simple mental tasks (dual task, DT), (3) running ST, and (4) running DT. Participants completed 8 walking trials (4 ST and 4 DT), followed by 8 running trials (4 ST and 4 DT). RunscribeTM wearable shoe sensors (Scribe Labs, Inc., Half Moon Bay, CA, USA) were utilized to assess pace (min/km), step rate (steps/min), stride length (m), and estimated power (W). Participants’ running pace was 30% faster during ST compared to DT and 19% faster during walking ST compared to DT. Running step rate was 3% faster during ST compared to DT but was 15% faster during ST compared to DT while walking. Stride length was longer in ST compared to DT during running (17%) and walking (4%) trials. Power was reduced in DT during running (16%) and walking (14%) relative to ST. Gait deficits were likely due to added cognitive demand during DT and added physical demand of a complex motor control activity during running trials. The added cognitive demands may better reflect the sport environment rather than gait alone. Additional research is warranted to continue studying gait deviations following concussive injury