Approximately eighty percent of adults experience low back pain. One of the most common causes is related to tight hip flexors. The hip flexor which is formally called the Iliopsoas or Psoas has two parts. One part originates on the low back or lumbar spine and inserts on the inner aspect of the thigh. The other part originates off of the iliac crest on the pelvis and inserts in the inner thigh area.

How is the tightening of hip flexors caused?
Hip flexors are a group of muscles in the hip which primarily consist of the iliopsoas and rectus femoris muscles. These muscles contribute to the action of flexing your hip joint, flexing your trunk forward, pulling your knees upward and helping to stabilize your lower body. These muscles are also used when we kick, run and help in stabilization when we perform lifts off the floor. They are also used a lot while sitting. So, the hip flexors perform the motion of hip flexion which is bringing the thigh upward. When we sit for long periods of time and do activities like cycling and running, we have a lot of hip flexion, which tightens up the iliopsoas muscle. When this muscle becomes tight, it creates an anterior pull on the pelvis, tilting the pelvis forward into an anterior pelvic tilt position thus increasing the lordotic curve and arching your back, which is the common cause of lower back pain. Long-term this can create muscle imbalances because tight muscles actually inhibit or turn off the opposing muscle group which in this case is the gluteus maximus.
Hip flexor tightness can be caused by
- Sitting for an extended period of time.
- It is commonly seen in runners with weak glutes and repetitive use.
- Participation in sports that require repetitive kicking.
Assessing the length of hip flexors
You should visit a physical therapist to evaluate your condition as well as assess the length of your hip flexors. This can be found through the use of a Thomas test.
What are the benefits of hip flexor stretches?
Many people feel tightness in their hip flexor muscles. Being sedentary, working at a desk and driving all the time creates really tight hip flexors. In addition when your hip flexors are tight, it creates the illusion of a distended gut and the abdominals start to fall out because of this. The tightness in these muscles also creates tightness in your lower back muscles leading to back pain.
The first step in preventing low back pain is to lengthen the hip flexor muscle. Many times we attempt to do that with static stretching. However, if this muscle has been shortened for long periods of time, static stretching may not be effective as the muscle often develops micro spasms which we call trigger points. Hence we need to relax the micro spasms before the static stretching is effective and one way to do that is through the use of a medicine ball as shown below.
Types of hip flexor stretches
Kneeling Hip Flexion Stretch
In order to perform this stretch, kneel down with one leg, with the other, in a flexed position. The hip flexors with the knee on the floor will be stretched by moving the leg into a more extended position. In order to increase the amount of stretch, try moving the arm on the same side that is being stretched, towards the opposite side. Since psoas is a bilateral muscle, meaning there is one on each side of the body, you want to repeat the same on the opposite side.
Trunk Extension Hip Flexor Stretch
This simple stretch can be performed by placing your arms around your hips and extending your trunk until you feel the stretch in the front of your hips. Be careful not to overextend, which can result in pain in your low back.
Standing Hip Flexion Stretch
This stretch can be performed by flexing one hip onto a chair with the opposite limb extended out. make sure that your toes are in line with your knees and lean forward to feel a stretch. This stretch will target both your hip flexors as well as your gluteal muscles.
Make sure to perform these exercises up to three times a day and you want to hold for up to 20 seconds. You want to perform them after sitting for more than an hour and also perform them if you feel tightness or pain in the front of your hip.