Mechanisms and situations of anterior cruciate ligament injuries in professional male soccer players: a YouTube-based video analysis

Background: Soccer is considered the most popular sport in the world concerning both audience and athlete participation, and the incidence of ACL injury in this sport is high. The understanding of injury situations and mechanisms could be useful as substratum for preventive actions. Purpose: To conduct a video analysis evaluating the situations and mechanisms of ACL injury in a homogeneous population of professional male soccer players, through a search entirely performed on the YouTube.com Web site focusing on the most recent years. Methods: A video analysis was conducted obtaining videos of ACL injury in professional male soccer players from the Web site YouTube. Details regarding injured players, events and situations were obtained. The mechanism of injury was defined on the basis of the action, duel type, contact or non-contact injury, and on the hip, knee and foot position. Results: Thirty-four videos were analyzed, mostly from the 2014–2015 season. Injuries occurred mostly in the first 9 min of the match (26%), in the penalty area (32%) or near the side-lines (44%), and in non-rainy conditions (97%). Non-contact injuries occurred in 44% of cases, while indirect injuries occurred in 65%, mostly during pressing, dribbling or tackling. The most recurrent mechanism was with an abducted and flexed hip, with knee at first degrees of flexion and under valgus stress. Conclusions: Through a YouTube-based video analysis, it was possible to delineate recurrent temporal, spatial and mechanical characteristics of ACL injury in male professional soccer players. Level of evidence: Level IV, case series.