This stretch is for two main muscles, the rectus femoris and the TFL. The rectus femoris is the only quad muscle that performs both hip and knee extension. When someone strains their quadriceps (which is really four muscles that produce knee extension), the rectus femoris is generally the muscle that has been strained. It is easily stained because it’s often tight. Sprinting and kicking a soccer ball are two activities often implicated in a strained rectus femoris.
The second part of the stretch, where you gently twist over your front leg, will stretch the TFL, a muscle that is also often tight. The TFL is a hip flexor, abductor (moving the leg away from the midline of the body), and internal rotator (rotates the leg to the inside) but it also acts to stabilize the knee via the IT band, thus it plays a role in maintaining healthy knees. For such a small muscle it plays a number of important roles. Like I’ve said before, it’s usually the small muscles that no one even realizes exist that can really mess you up.
Keys: Keep perfect posture. Place your front leg directly in front of you and the back foot lying flat on the bench. Your back knee should be on the ground. Squeezing the glute of the leg being stretched will intensify the stretch. After 15 seconds, gently twist over the front leg. Hold for another 15 seconds.
Many people quickly become aware of how tight their hip flexors have become upon initiating this stretch. You may also find that one side is much tighter than the other. This indicates asymmetry. Asymmetry is often referred to as a “unilateral deficit” among science geeks or “sh*t is messed up on one side of your body” among the lay person.
Regardless of how you describe it, asymmetry is a potential problem or it could even be the source of a current problem. Asymmetries are not good as they indicate something has gone wrong. Eliminating asymmetries often leads to pain magically going away. It’s an absolutely fascinating subject and you really begin to understand how the body works as a system, but it’s too complex to address in this post.
You may not be able to hold the stretch for 30 seconds. It can be quite uncomfortable the first few times you try it. Find a bench that is not so high that you can’t comfortably get into position, nor one that is too low that you won’t feel the stretch. This stretch can be done before, during, or after the workout. I generally have people do it twice on each leg.