Poor peak dorsiflexor torque associated with incidence of ankle injury in elite field female hockey players

This study set out to determine the incidence of ankle injuries amongst provincial female field hockey players in KwaZulu-Natal (KZN), South Africa, during the 2004 field hockey season and relate this to their injury and playing profile, proprioceptive ability and peak isokinetic torque of the ankle plantar and dorsiflexor muscles. Players participating in the senior, U21 and U19/high school provincial A teams (n = 47) detailed their hockey playing and training history and injuries sustained during the 2004 season. A subsample of injured and matched, uninjured controls (n = 18) underwent anthropometric, proprioceptive and isokinetic testing. Incidence of injury in the 2004 season was 0.98 per player or 6.32 injuries per 1000 player/h^-1, with 25.5% of players (n = 12) reporting injuries to the ankle joint. All ankle injuries occurred on artificial turf and 75% occurred during a match. Forwards and links that had been playing for six to seven years presented with the highest incidence of ankle injuries. Injured players were able to maintain balance on a proprioceptive board for 10.31 ± 8.2 s versus 23.9 ± 15.3 s in matched, uninjured controls (p = 0.078). Both mean (27.4 ± 5.5 Nm versus 32.7 ± 4.7 Nm) and median (27.0, 23.0-31.5 versus 31.8, 30.0-35.1 Nm) peak isokinetic torque of the dorsiflexors of injured legs was significantly lower than in uninjured, contralateral legs of the injured players (p = 0.01 and 0.03, respectively). Poor peak dorsiflexion torque in the injured leg was identified as a factor associated with ankle injury in this sample of injured, elite field hockey players.