Why is it important to have good hip extension when running?
There are many answers to this question, so we will take a close look at each of them in turn. During a normal running gait, the foot must dorsiflex (toes up towards the shin), and then the knee flexes (heel up towards the bum) so that the foot can clear the ground as the hip extends backwards pulling the whole leg back behind your torso. The further back the leg can get, the longer the stride length. The longer the stride length (in general), the quicker you can cover ground. When you factor in increased cadence and a long stride length, you get an increase in speed.
So, why is good hip extension important?
Well, often the first indication of decreased hip extension is pain. The most common complainers are the low back, hamstrings, and quadriceps. A person with limited hip extension will often complain about low back pain, hamstring fatigue during the run, “weakness” in their spine, back pain during menstruation, chronic quadriceps tightness, and difficulty rising from a seated position.
What are the main differences between good and bad hip extension?
Normal (good) hip extension shows a longer length between one knee and the other when looking from the side, good heel height (to the level of the buttock often), and the look of an almost 90 degree flexed knee. When you get a decrease in hip extension, you get a simultaneous decrease in flexion of the knee.
What can cause poor hip extension?
There are three primary muscles that can be involved if the hip does not extend properly. These are the Psoas, the Iliacus, and the Rectus Femoris. Fortunately, you can do a little testing to find out which one is involved. For example, because the Psoas and Iliacus do not cross over the knee, but the Rectus Femoris does, if hip extension is decreased when you flex your knee, you know the Rectus Femoris is involved. Thankfully you can also rule out the Rectus Femoris from causing the hip extension problem if there is no decrease on hip extension with knee flexion.
There can also be a few more reasons why the hip will not extend normally. Shortened Tensor Fascia Latae can also limit hip extension, as can a shortened Gluteus Medius and Minimus due to increased hip abduction during all gait phases. A shortened Sartorius can also limit hip extension. Finally, there is a fascial line up the leg and into the torso which can become tight and rigid, and it too can limit extension at the hip.
Here is a simple stretch you can do regularly to help stretch out all of your hip flexors, which will allow your hip to extend better.