Prospective studies into the causation of hamstring injuries in sport: A systematic review

Aim: To identify and determine specific predisposing factors related to hamstring injuries in sport. Method: Systematic review. Data sources: Key word search of seven databases (AMED, Cochrane Systematic Review Database, EMBASE, MEDLINE, PEDro, SMART and SPORTDiscuss). Four concepts with key words and truncated key words were used in the search. Other methods used included hand searching, snowballing and personal communication. Results: The search strategy implemented generated two experimental studies and five observational studies which were reviewed. All seven papers considered predictive factors for injury with varying results. Limited evidence was apparent linking pre-season neuromuscular proprioception, age, race, pre-season hamstring/quadriceps muscle strength and a past history of injury as predictive variables for subsequent hamstring injury. The most conflicting findings were the predictive values of hamstring strength and previous hamstring injury. Conclusion: Risk factors identified by the studies were conflicting and no single risk factor was found to be consistently associated with hamstring injury. This may in part be due to the wide variety in research methodologies which hinders comparisons between studies being made. Further research using larger cohorts and measuring a broader range of variables is required to reflect the multi-factorial nature of hamstring injury. From this it may be possible to establish consistent risk factors associated with hamstring injury in order to design preventative and rehabilitative programmes in the sporting arena. (c) 2006 Published by Elsevier Ltd.