Hamstring strains represent up to 15% of all injuries sustained during participation in running sports and most of the football codes, making them a costly injury due to the high frequency in injuries. Inadequate neuromuscular control may have contributed to the original injury, and that it remains as a risk factor for further injury.
Misjudgement in movement with errors occurring when the hamstring muscle group is strongly and rapidly contracting, as it is during late swing phase through ground contact to the mid-stance phase, may increase the muscle length and torque demands, and alter the length-tension relationship of the hamstring muscle group in a way that cannot be resisted without injury. Thus, any method of improving the performance of the sensorimotor system could have possible benefits for hamstring and other lower limb injury prevention.
This study examined the effect of the HamSprint Drills training programme and conventional football practice warm-up on lower limb neuromuscular control in 29 footballers from one professional Australian Football League club. Without vision of the contact point, participants performed 40 backward swing movement trials with each leg and made a judgment of the magnitude of each movement.
Participants were randomized to either an intervention or control group that performed different procedures in the warm-up prior to football practice sessions over a 6-week period, and then were re-tested. The intervention group performed the HamSprint programme-drills specific to the improvement of running technique, co-ordination and hamstring function. HamSprint programme-drills consisted of six sessions of three drills of increasing difficulty, repeated three times over a 30 m interval, performed twice per week after a 10 min warm-up that comprised stretching, jogging and the practice of 2–3 drills from the previous session.The control group performed their usual warm-up of stretching, running, and increasingly intense football drills.
Backward leg swing extent discrimination was significantly better in players following the 6-week HamSprint programme when compared to discrimination scores of players who performed their usual practice warm-up only. Significant improvement was observed in lower limb neuromuscular control in movements similar to the late-swing early stance phase of running. The HamSprint program can therefore improve control in a specific aspect of sensorimotor system performance, and this may be useful particularly in athletes who have lower function levels or those deemed at risk of hamstring injury. (Cameron ML, Adams RD, Maher CG, Misson D: Effect of the HamSprint Drills training programme on lower limb neuromuscular control in Australian football players. Journal of Science & Medicine in Sport. 12(1):24-30, 2009).