Yes, it sounds like a hip flexor issue. There are a lot of muscles that go in to flexing the leg (ie, bringing the knee up toward the torso and then releasing it). That tiny muscle in the crease is among them. The psoas, a huge muscle that attaches inside your ribs and spine to your pelvic cradle (and is sometimes referred to as one of the “core” muscles), also plays a part. I mention it because sometimes, if the psoas is doing a lot of work and gets tired, you start to call on that tiny muscle in the crease to compensate for the psoas’ fatigue and you get that “snapping” feeling of that small muscle at the start of a run.
So, yes, an increase in swimming may have led to a hip flexor problem. Your psoas is probably working pretty hard in the twist and flex of swimming, so that when you go for a run, it isn’t able to do its usual work in lifting your knees. As a result, the hip flexors work harder to pick up the slack. Weak adductors (muscles to the inside of the leg that work to bring the leg back to centre) can also be involved. That means you need to consider any changes in cycling, especially if you’re a “knees hitting the top tube” cyclist. And…weak gluteal muscles. So, uh, basically any muscle group that, due to its weakness or excessive strength, may be contributing to rotation of the leg in or out.
Other possible links to tired hip flexors:
- an increase in the amount of time you spend in the aero position on your bike. The hip flexors are cramped and may also be doing more than they should in lifting your knee. This one is complicated and, although I’ve seen the link, I have to admit that I don’t fully understand it.
- an increase in the amount of time you spend sitting down, especially if it is not long after a workout. Cramped hip flexors are never happy hip flexors.
- driving a car with a manual transmission. Hovering your left foot over the clutch can do quite a number on a hip flexor!
The good news is that, while understanding the problem and the causes can be super-complicated, the fix is easy. Bring out the foam roller! Put it out on the ground, kinda off to an angle from your centreline. Lie down on your stomach, and stick the affected leg out to the side, bent at the knee, so that the inside of the knee is touching the ground. Now put the foam roller in that “crease”, perpendicular to your thigh. You should feel the tension starting in your abdomen and running toward the adductor. Roll slowly. If the hip flexor is in rough shape you may not even be able to roll. That’s OK. Just rest the muscle on the foam roller for 30 second intervals, trying to put more weight on it.
Go to http://www.bekcraved.com/...0/17/how-im-rolling/ and scroll down to “Groin, Hip Flexor & Adductors”.
Good luck!
Thanks! All of the above
More time in the aero position
more time sitting driving a manual trans
I will try to roll it out!