PRIMARY OBJECTIVES: The aim of this study was to identify the type and incidence of running abnormalities following TBI when compared to a group of healthy controls (HC) and report if these abnormalities were similar to those which are present during gait. RESEARCH DESIGN: A convenience sample of 44 people with TBI receiving therapy for mobility limitations and a sample of 15 healthy controls (HCs). MAIN OUTCOMES AND RESULTS: Spatio-temporal, kinematic and kinetic data at self-selected walking and running speeds were collected. People with TBI ran at significantly slower self-selected speeds than HCs. At matched running speeds, people with TBI used a higher cadence and shorter step length. The most commonly observed biomechanical abnormalities occurred at the knee during stance phase. Few trunk, pelvic or hip abnormalities were detected. Ankle power generation at push-off was significantly reduced, whereas hip extensor power generation at initial contact was significantly increased. CONCLUSION: Many people with TBI may actually be capable of running, despite the presence of significant biomechanical abnormalities during gait. A stable trunk may be an important requirement for people following TBI to achieve running.