With the hips being one of the most powerful joints in the body and one of the most used joints, it's great to see that the physio-world is starting to look at the whole body for joint and muscle aches and pains. With the hips being such an important factor, any dysfunction, big or small, can rob someone of athletic or everyday performance. The squat is a very basic movement; tilt the hips, keep your chest up, and bend your knees. However, so many people can never perform this movement with perfect form. Why? There are two common possibilities.
#1: Posterior Weakness or Weak Glutes ​​​​​​​ This falls under the category of compensation dysfunction, where your quads, back, and/or hip flexors take the brunt of the force. This is because you are telling your body to do a movement and it's trying its best to perform, meaning it will activate muscles that should not be used to compensate for muscles that aren't working properly.
Gluteus Maximus: the prime mover for hip extension, so weak glute max means weak hip extension. People who with weak glutes will start to fall forward during their eccentric phase of hip extension, or the lowering phase of the squat. Proper eccentric control needs to be paired with core tension to keep someone upright and stable in their squat. So, what happens when weak glutes try to drive into hip extension from the bottom of the squat, the low back muscles will start to activate and they do not have the strength to produce the movement. This is where the common injury of low back pain starts to show up in people that are new squatters or people who are lifting too much with poor form.
Hip Flexors: Similarly with the low back, when glutes are too weak (and core for that matter) to take the weight, the anterior musculature of the hip will also start activating. They are going to help keep someone’s balance and start pulling someone into a deeper squat than the glutes will allow.
Testing Glute Strength:
Find a table that’s about waist height (a training table would be ideal) and stand with your hips directly up against the edge of the table.Lean forward so your entire torso is on the table.Lift one leg straight back and flex your knee to ninety degrees.Without letting your knee drift out to the side or letting your lower back extend (increasing lumbar curvature), lift your foot towards the ceiling. You should feel a tightness in your glutes. Now have a friend try to push down on your thigh with light, but steadily increasing force. If you have weak glutes, it shouldn’t take a huge amount of effort to break your hip position. If your leg starts to turn or drift sideways or your lower back starts to move, those are compensatory mechanisms and they indicate that your hip extension needs a little tender loving care. Do this test on both legs, one at a time.
#2: Anterior Tightness (aka Tight Flexors)
Hip flexion is mainly done by two muscles of the quadriceps group: the sartorius and rector femoris, as well as the iliopsoas, which is a deep hip muscle. These muscles often become tight because of inactive positions that we commonly take in the modern workplace and school classrooms, sitting.
Similar with weak glutes, if hip flexors are tight people will lean forward during the movement and will increase the activation of the quadriceps and deactivation of the glutes. Now that you are in the bottom of your squat and all the hip flexors are activated, you need to use your quadriceps to extend your knees. The problem is, two out of the three hip flexors are attached to your quads and they are already firing.
Tight hip flexors can also mean poor hip mobility. In a squat, you should have a passive flexion for your depth and you shouldn't have to activate your hip flexors to achieve it.
Testing Hip Tightness: Thomas Test
Lie down supine with your legs hanging off the edge of a table. (Again, a training table would be ideal.) Pull your knees to your chest and hold them there with your arms. Extend one of your legs while keeping the other held to your chest. Let the extended leg hang off the edge of the table. Have a friend observe the location of your knee (on the extended leg) compared to the position of your hips. Your knee should hang lower than the table. If it is above the table or even in line with it, then this is a positive indication of hip flexor tightness.