A couple months ago I did a post about quad and hamstring muscle imbalances. Today, I am going to do the second post on muscle imbalances focusing on the hip flexors and glutes. The hip flexors lay in the front of the hip and act to bring your leg closer to your trunk. The glutes (or hip extensors) lay in the back of the hip and act to bring your leg away from you. Most people have tight and short hip flexors, but long and weak glutes. This is similar to the quads (dominant) and hamstring (weak). This is primarily due to the fact that most people spend a majority of their time sitting and do not move enough in the right ways.
An imbalance between the hip flexors and glutes can cause a multitude of injuries including low back pain, hip pain, knee pain, ITB syndrome, and muscle strains. The body is a chain, so a problem in the hips can affect both the joints above and below it. Weak hips means an unstable base for the knees and spine. One of the most common problems with tight hips flexors is low back pain because some of the hip flexors originate from the low back as you can see in the picture below. The tight muscle pulls on the spine and can result in pain.
The primary hip flexor is the iliopsoas (iliacus + psoas = iliopsoas). The TFL, sartorius, rectus femoris (one of the quad muscles), and adductors also contribute to hip flexion. The TFL attaches to the IT band, so that is why tight hip flexors can contribute to ITB syndrome.
The primarily hip extensor is the glute maximus. The glute medius and the hamstrings also assist with the motion.
The best way to combat injuries from the hip flexors and extensors being out of balance is to make sure you have enough flexibility and they are equally strong.
My favorite hip flexor stretch is shown below on the left. In half kneeling, perform a posterior pelvic tilt and push your hips forward until you feel a stretch in the front. You can also reach your arm up and overhead to get the IT band.
The active warm up I posted last week is another great way to keep your hips flexible and balanced. If you took a car ride to get to where you are exercising, definitely do the active warm up (or at least some leg swings!) to loosen your hips after sitting for a little while and to help prevent injury.
Hip flexor strengthening exercises include leg lifts laying on your back (aka straight leg raises: lay on your back and lift one leg straight up towards the ceiling). You can make this harder by putting a band (such as these) around your lower legs/ankles. Glute strengthening exercises include simply tightening your glutes (squeeze your butt cheeks together!), bridges, and leg lifts laying on your stomach (aka prone hip extension: lay on your stomach and lift one leg straight up towards the ceiling while contracting your glutes). Again, you can make the leg lifts harder with a band around your lower legs/ankles.
One of the easiest, most specific exercises for glute activation is the butt tighteners. What I love about them is you can do them anywhere, anytime. If you have been sitting at your desk for a while, just stand up and do a few butt squeezes. I always do them on the plane when I get up to walk around.
Another favorite exercise of mine is to put a band around your lower legs/ankles and walk forward, backwards, and sideways 10-20 steps each direction. Keep your knees slightly bent and you will feel you hip muscles working. Forward gets the hips flexors, backwards gets the hip extensors, and sideways get some lateral movement because those muscles are important for overall muscle balance too!
Let me know if you have any questions!