Hamstring strain injuries are still the single most acute, non-contact, sports injury in football. Despite the fact that more and more effort is being invested in (secondary) injury prevention, (re-)injury rates continue to increase throughout the years (due to the popularity and the evolving athletic demands of the football game). Contemporary research in the field of hamstring injury risk identification has pointed out the importance of hamstring fiber structure in the muscle's injury vulnerability. Shorter muscle fascicles have been associated with lower hamstring strength and a history of strain injuries in cross-sectional and retrospective study designs. Nonetheless, these studies systematically investigated the biceps femoris’ muscle tissue at mid-thigh level, where the injury never occurs instead of assessing its proximal myotendinous junction (MTJ, proximal transition between tendon and muscle fibers), where the strain lesion presents itself in the majority of cases. Consequentially, contemporary prevention exercises also focus on improving hamstring strength and strengthening the muscle's structural features at mid-thigh level. Although these exercises evidently render some effect at level of the most vulnerable MTJ, they are not specific nor effective enough to provide the athlete with the best injury prevention. This project aims to improve pathophysiological  insights and associated injury prevention by using a comprehensive MRI protocol in a prospective design.