Hamstring Strain Injury Patterns in Spanish Professional Male Football (Soccer): A Systematic Video Analysis of 78 Match Injuries.

Background: To the best of the authors' knowledge, the different injury mechanisms of the hamstring muscle group have not been defined in detail in men's professional football. For this reason, the main aim of this study is to determine the mechanisms and contextual patterns associated with hamstring muscle group injuries in professional male football players in competition, using a systematic video analysis method. Methods: Video recordings of official matches from two consecutive seasons (2017/18 and 2018/19) of the Spanish First Division of Football (LaLiga^TM) were used for this research. The process to determine the moment of injury was carried out by two independent evaluators using an ad hoc observation tool and, subsequently, all relevant data were collected to detail the specific patterns of injury events observed. Results: In total, 78 cases of hamstring injuries were included for the final analysis of specific patterns. The most outstanding results were that, (1) although the sprint-related pattern (SP) is predominate (54%; 42 cases), the combined pattern 2 (COMB2) is another mechanism that appears frequently (26%; 20 cases), (2) within the SP, curved runs show a greater number of cases (52% of SP; 22 cases), (3) the majority of the injuries occur without contact (83%; 65 cases) and with the presence of the ball (88%; 69 cases), and finally, (4) the most injured positions were fullbacks/wingbacks (28%; 22 cases), central defenders (27%; 21 cases), and wingers/wide midfielders (23%; 18 cases). Conclusions: The SP remains the most frequent pattern in hamstring injuries; however, the present study presents other mechanisms that are also quite common and should be considered, such as curvilinear runs in SP and COMB2.