Pelvis, knee and hip movement during the swing phase of the gait cycle weren’t improved following static hamstring stretching, a studyfrom Austin Peay University in Tennessee has found.
Writing in the Journal of Athletic Training, researchers described an experiment in which 34 recreational runners ran on a treadmill while the researchers measured the range of motion in their pelvis, hip and knee during the swing phase of the gait. (The swing phase is from toe-off to landing.) After the first run, half the subjects did nothing, while the other half did a classic runner’s stretch – a straight leg raise held for 30 seconds, three times, with the hope of stretching the hamstrings. Then both groups repeated their treadmill runs, and the researchers again measured pelvis, hip and knee movement.
Both groups had greater movement at the three bodily sites on the second run, thanks to being warmed up from the first run. But the stretch group and the sit-around group had similar improvements; the three 30-second hamstring stretches had no effect on increasing range of motion at the three sites.
Research is increasingly showing that pre-run static stretching is either ineffective, as in this study, or detrimental to performance, as in other studies showing less power and strength after a pre-run static stretch. Static stretching is best saved for after runs, when your muscles are already warmed up and are receptive to being elongated. Before runs, dynamic stretching is a better way to prime your muscles for activity.