The Iliacus muscle is a powerful hip flexor and a huge contributor to low back pain in modern age. The Iliacus muscle gets chronically tight when sitting in chairs, something we all frequently do in today's world. Read on to learn about what the Iliacus muscle is, how to determine if it is causing your pain, and how to release it.
Iliacus Muscle Anatomy
The Iliacus muscle is a hip flexor muscle on the front of the body that can cause a lot of pain when tight. Iliacus connects from the top of the hip, travels inside the pelvis, and connects again to the top of the femur. To feel the Iliacus muscle, try digging your thumb on the inside face of your hip bone, 0-2 inches above the waistline.
Iliacus Muscle Function
The Iliacus muscle functions in hip flexion, as in bringing the knee to the chest. Activities like kicking a soccer ball, performing tuck jumps, and climbing stairs require substantial effort from the Iliacus muscle. Iliacus muscles also can work very hard when doing sit-ups, although the abdominals should be the main mover .
There is also evidence that the Iliacus muscle also has function in trunk and pelvic stability . Iliacus has the power to tilt the pelvis forward (anterior tilt - think Donald Duck posture), which is great in small doses but painful in chronic form.
Iliacus Muscle Pain Symptoms
Classic Iliacus Muscle Pain
Iliacus muscle pain is common in people who sit in chairs the majority of their days, particularly while slouching . This is due to the shortening of the Iliacus muscle while in the sitting position. A short, tight Iliacus muscle is a recipe for low back pain. Desk workers should be very cognizant of their Iliacus muscles while sitting too long, and should become proficient in Iliacus muscle release and stretch.
Iliacus Muscle Referred Pain Pattern
Iliacus muscle pain is most commonly felt in the low back, but Iliacus pain can also manifest at the upper thigh . The bright red in the image below details where the Iliacus (and Psoas) muscle refers pain on the body. The image only shows pain caused by one Iliacus muscle, but generally both Iliacus muscles are tight together and cause pain on both sides.
Iliacus Muscle Referred Pain Chart 
Additional Iliacus Muscle Pain Symptoms
- Vertical low back pain along the lumbar vertebrae 
- Pain and difficultly when standing up after sitting for a long time 
- Comfort when side-lying in the fetal position 
- Difficulty and pain when doing sit-ups 
- Stiffness in the hips and groin 
Iliacus Muscle Release
Iliacus Muscle Release Tool
The best way to release the Iliacus muscle of its tightness and trigger points is with deep tissue massage. It is important that deep tissue massage is done first because a knotted, tight muscle is near impossible to stretch.
Iliacus muscle deep tissue massage can be done with the hands of a professional, or with an Iliacus release tool like QL Claw. QL Claw is great for Iliacus muscle release with its comfortable, versatile design. Unlike other massage products, QL Claw can release all 5 muscles that could be causing low back pain and more.
Iliacus Muscle Release Using QL Claw
QL Claw has written and video tutorials on the subject of Iliacus muscle release, as well as all other muscles (Psoas, QL, Gluteus Medius, and Piriformis) that could be bringing you pain. Learn more at the link below!
Iliacus Muscle Stretch
After successfully releasing the knots and tightness in the Iliacus muscle, it will be easier to stretch and lengthen the muscle. Perform a hip flexor stretch such as the couch stretch to lengthen the Iliacus muscle and relieve tension on the low back.
 Donnelly, Joseph M. Travell, Simons & Simons Myofascial Pain and Dysfunction: the Trigger Point Manual. 3rd ed., Wolters Kluwer Health, 2019.
 Davies, Clair, and Amber Davies. The Trigger Point Therapy Workbook: Your Self-Treatment Guide for Pain Relief. 3rd ed., New Harbinger Publications, Inc., 2013.