Higher frequency of hamstring injuries in elite track and field athletes who had a previous injury to the ankle - a 17 years observational cohort study

Background Inversion injury to the ankle and hamstring injuries are common problems in most sports. It is not known whether these injuries constitute a predisposing factor or a precursor of injury or re-injury of these anatomical locations. Therefore, we wished to test the hypothesis that a previous inversion ankle injury exerted a significant effect on the chance of an athlete suffering from a subsequent ipsilateral hamstring injury and vice versa. Methods In an observational cohort study over 17 years (1998-2015), 367 elite track and field athletes, were grouped according to their first traumatic isolated ankle or hamstring injury. Fifty athletes experienced both injuries. The Mann-Whitney U and Chi-square tests (p < 0.05) were performed to test possible associations of ankle and hamstring injury with age, gender, athletics discipline, grade, and type of antecedent injury. Results Athletes with a preceding ankle injury had a statistically significantly higher chance of experiencing a subsequent hamstring injury compared with athletes who had experienced a hamstring injury as their first traumatic event (x2 = 4.245, p = 0.039). The proportion of both ankle and hamstring injury events was not statistically different between female (18%) and male (11%) athletes. Age and grade of injury did not influence the proportion of ankle and/or hamstring injury events. Conclusion There is a statistically significantly higher frequency of hamstring injuries in elite track and field athletes having experienced a previous ankle ligament injury.