Hip flexors often get a pretty bad rap for being too tight – usually the result of too much sitting, but how many of us know if our hip flexors are actually too weak? We all know that excessive tightness limits muscle strength and this applies to our hip flexors as well.
The hip flexors, namely the psoas major and iliacus are responsible for hip flexion (!) or the action of bringing the knee towards the chest but also play a role in flexing the trunk on the hip (as in a sit-up). Rectus femoris also has a role in hip flexion but also knee extension as one of the four components of the quadriceps muscle.
When the hip flexors are shortened, they can cause anterior rotation of the pelvis, resulting in overextension of the lumbar spine. This places the hamstrings in an overstretched and weak position and places the glutes into a disadvantaged position.
Try this: in standing bend forward and grab the skin at the front of the thighs with your hands. Now try squeezing your butt. What happens? Nothing? Exactly. Now, without releasing the tissue, attempt to stand up straight. Pretty damn uncomfortable right? That is basically the effect of hip flexors that are too tight – an inability to effectively use your glutes and attain full hip extension. It’s pretty hard to snatch, clean and jerk, squat, deadlift, kettlebell swing, run, jump, etc without full hip extension. Now if you are constantly getting through life and Crossfit without full hip extension, what impact does that then have on your lumbar spine, hips, knees and ankles??
How can you tell if your hip flexors are too short?
Thomas Test: http://www.youtube.com/watch?v=4mnjUi-41fI
How can you tell if your hip flexors are weak?
- Stand against a wall, with your feet about 10cm away from the wall, head and shoulders touching.
- Lift one knee up towards your chest, as high as possible, keeping the standing leg straight. The leg needs to go past 90 degrees (past horizontal). Hold for 30 seconds.
- Pass: if you are able to hold your thigh past 90 degrees for the entire 30 seconds.
- Fail: if your leg drops below 90 degrees before the 30 seconds is up.
- Make sure to compare sides.
- Make sure that the knee is straight and in line with the body. If it is being held out to the side or crossing the midline, you may be compensating by using other muscles such as TFL or adductors.
If you failed the test, then it’s time to do some work to strengthen your hip flexors. The test above can actually be used as an exercise as well. Try doing sets of 10, holding each rep for as long as possible (up to a maximum of 30 seconds), without letting the knee drop below the horizontal.