Australian researchers encourage neuromuscular training.
When the hamstring is strained, the normal signals between neurons and muscle shut down. This “neuromuscular inhibition” limits normal muscles’ function and the effectiveness of strength and stretching rehabilitation. Over time, the injured muscle atrophies, strength imbalances increase, and the angle of peak torque changes (i.e., the knee becomes less stable).
These “maladaptations” are long-lasting and raise the risk of injuring the area again.
“We have evidence for reduced activation many months after return to sport,” Shield told Runner’s World Newswire via email. “We have more recent data (as yet unpublished) that athletes use their previously injured biceps femoris [a hamstring muscle] about half as much on the injured side as the uninjured side when doing a Nordic hamstring curl. This data is, on average, 10 months after injury, so the change appears pretty permanent.”
Physical therapists likely avoid exercises such as Nordic hamstring curls owing to the high forces generated by the move.
But if athletes re-establish pathways between nerves and muscle, they may be better able to restore full muscle strength and function to the hamstring and reduce their chances of getting injured again, the researchers suggest.
Shield notes that many injuries result in neuromuscular inhibition. The concept isn’t new or radical, he says, it just hasn’t been adequately addressed.
Additionally, neuromuscular training isn’t a “magic solution”, writes Shield, but one of many factors athletes and physical therapists should consider.