Millions of concussions occur every year in the United States. The public interest in concussion has increased after a number of high-profile deaths in high school athletes from sports-related head trauma and in some professional athletes from chronic traumatic encephalopathy. One of the most active areas of research in sports medicine during the last decade has been the evaluation and management of concussion. In this second article of a two-part series, we provide an overview of the latest scientific advances in concussion research. This overview includes an update on the pathobiological changes that occur during concussion and the results of biomechanical studies. In addition, to aid the practicing clinician, we review the literature on proven and currently studied concussion risk factors, including a history of concussion, fatigue, and age. Genetic polymorphisms and biomarkers may provide risk-prediction capability, but at present the research remains inconclusive. Diffusion tensor imaging and functional magnetic resonance imaging are promising technologies that reveal more sophisticated data about the impact of concussion on the brain. We review the existing literature on the application of these neuroimaging modalities to sports concussion. An update from the Fourth International Conference on Concussion in Sport, with highlights of new recommendations, and the presentation of the third edition of the Sports Concussion Assessment Tool to evaluate acute concussion, concludes our review.