Altered hamstring strength profile in Gaelic footballers with a previous hamstring injury

Hamstring injuries are common in many sports involving high-load eccentric hamstring activation, including Gaelic football. Eccentric hamstring peak torque (PT) and hamstring angle to peak torque (AngPT) have not been examined in previously injured Gaelic footballers. This study aimed to determine whether significant hamstring and quadriceps PT deficits were present in Gaelic footballers after a hamstring injury. Concentric hamstring and quadriceps PT at 60 and 180 degrees/second (°/s) and eccentric hamstring PT at 30°/s were measured using an isokinetic dynamometer in 18 male Gaelic footballers (nine previously injured, nine controls). Hamstring AngPT, as well as hamstring and quadriceps PT and PT ratios were analysed. For previously injured limbs, hamstring AngPT occurred at significantly shorter muscle lengths (p = 0.038) than for the contralateral uninjured limbs in eccentric testing only. There were no other significant differences (p > 0.05) at any velocity, for within-subject or between-subject comparisons. The results showed that the previously injured hamstrings generated their eccentric hamstring AngPT at significantly shorter muscle lengths than the contralateral hamstrings. The results imply footballers with a previous hamstring injury who have returned to full participation may remain at increased risk of re-injury because of an alteration in their eccentric hamstring AngPT.