With warmer weather and longer days, our activity has increased. Unfortunately so has some of the pain and limitations. What is the ilium bone? What is the iliac crest? What muscles attach to the iliac crest? What are the causes of ilium pain? What are the treatment options? Let’s dig in.
What is the Ilium Bone?
The ilium is the largest of the three bones that compromise the pelvis. There is a right and left ilium bone that meets with sacrum to form the right and the left sacroiliac joint. This is illustrated in the image to the right. The ilium bone has two parts: the body and the wing.
What is the Iliac Crest? And What is Iliac Crest Pain?
The iliac crest is the top border of the ilium. This is outlined in red in the diagram below. If you put your hand on your waist and press firmly you will feel a boney surface. This is your iliac crest. If you wear a tight belt, it may synch up onto or near your iliac crest.
What Muscles Attach to the Iliac Crest?
The iliac crest is the site where many important muscles attach. These include the:
- Tensor Fasciae Latae: A thin yet powerful muscle that stabilizes the hip, extends the hip and along with the gluteus maximus forms the iliotibial band. (1)
- Internal and External Obliques: Important abdominal muscles that assist with respiration and produce trunk rotation and side-bending.
- Latissimus Dorsi: A large, triangular muscle in the back that is important in the flexion, extension of the trunk, and various shoulder movements (2)
Are the Other Muscles that Attach to the Ilium Bone?
Yes. Immediately below the iliac crest are the powerful and important gluteal muscles. These muscles attach onto different parts of the ilium below the iliac crest. The most important muscles are:
- Gluteus medius: A large fan shape muscle that moves the hip joint
- Gluteus maximus: The largest and heaviest muscle in the body, it extends and laterally rotates the hip joint.
- Gluteus minimus: The smallest of the gluteal muscles it provides hip stabilization and movement away from the body (abduction).
- Rectus Femoris: A thin straight muscle that starts on the forward portion of the ilium and as part of the quadriceps muscle group flexes the hip and extends the knee.
Ligaments are thick bands of connective tissue that connect bone to bone. There are several ligaments that attach to the ilium bone. These include the dorsal sacroiliac ligament, long posterior sacroiliac ligament, and iliolumbar ligament. The iliolumbar ligament connects the tip of the L5 transverse process to the inner lip of the iliac crest and is critical in the stability of the sacroiliac joint (3).
What Are the Causes of Ilium Pain?
There are many different causes of ilium pain. For ease, I have broken them down into two groups: Direct and Referred.
Direct causes are those directly related to the ilium bone itself and the structures that attach to it. Referred pain is pain that is felt or perceived in a part of the body other than its actual source. The classic example of referred pain is someone who is having a heart attack and feels pain radiating down their arm. The pain is felt or perceived in the arm while the real tissue injury is occurring in the heart.
Direct causes of ilium pain include:
- Fracture or trauma to the ilium bone (4)
- Cancer of the bone
- Inflammation or injury to any of the tendons and muscles that attach to the ilium: Remember tendons are thick pieces of connective tissue that connect muscle to bone. There are a large number of muscles that attach to the ilium. These include the tensor fascia latae, internal and external obliques, latissimus dorsi, gluteus maximus, medius and minimums, and rectus femoris. Each muscle has a tendon that can become inflamed, injured, or torn and become a source of ilium pain. The muscle itself can go into spasm or become injured or torn and become a source of ilium pain.
- Ligament injury to any of the ligaments that attach to the ilium: These include the sacroiliac joint ligaments and iliolumbar ligaments.
- Pregnancy and childbirth (5)
Referred source of ilium pain include:
- Sacroiliac joint injury or instability
- Lumbar disc injury: disc protrusions or herniations can cause referred pain into the ilium (6)
What Can I Do for Ilium Pain?
For the best clinical outcomes, one needs to identify and treat the underlying problem or source of the pain. Physical examination is critical and often times can help identify the underlying problem or problems. An X-ray can identify fractures or cancer lesions in the bone. An Interventional Orthopedic trained physician can easily sort through whether the ilium pain is coming from a muscle, tendon, or ligament injury, or, is being referred from a different source. In-office ultrasound is useful to evaluate these structures and avoids a trip to the MRI center and possible viral exposure. Steroids should be avoided as they are toxic to muscle, tendon, and cartilage (7).
The Centeno-Schultz Clinic are experts in the treatment of ilium pain and the diagnosis of muscle, tendon, and ligament injuries. Treatment options include PRP and stem cells which can accelerate healing. To learn more about Interventional Orthopedics please watch the video below.
The ilium bone is the largest of the three bones that compromise the pelvis. The iliac crest is the top border of the ilium and the site of attachment of important muscles which include the internal and external obliques, tensor fascia latae, and latissimus dorsi. The gluteal muscles and rectus femoris muscle attach to other parts of the ilium bone. Ligaments are thick bands of connective tissue that connect one bone to another. Many ligaments attach to the ilium which includes the sacroiliac joint and iliolumbar ligaments.
Causes of ilium pain can be categorized as either direct or referred. Direct causes of ilium pain include fracture, trauma, cancer, inflammation, or injury to any of the tendons, muscles, or ligaments that attach to the ilium. Referred sources include sacroiliac joint injury or instability and low back disc injuries.
The best treatment involves identifying and treating the underlying injury. Ultrasound is a powerful diagnostic tool as muscle, ligament, and tendon injuries are easily identified and avoid MRI imaging and the risk of viral infection. Steroids are toxic and should be avoided. PRP and stem cells are viable and effective treatment options (8). The Centeno-Schultz Clinic are experts in the diagnosis and treatment of ilium and iliac crest pain.
If you have exhausted conservative care and still are plagued by iliac crest pain, please schedule a Telemedicine consultation with a board-certified, fellowship-trained physician who can review your history, prior treatments, and current imaging and discuss regenerative options to get you back into the game.
1.Gottschalk F, Kourosh S, Leveau B. The functional anatomy of tensor fasciae latae and gluteus medius and minimus. J Anat. 1989;166:179-189.
2.Bhatt CR, Prajapati B, Patil DS, Patel VD, Singh BG, Mehta CD. Variation in the insertion of the latissimus dorsi & its clinical importance. J Orthop. 2013;10(1):25-28. Published 2013 Mar 7. doi:10.1016/j.jor.2013.01.002
3.Vleeming A, Schuenke MD, Masi AT, Carreiro JE, Danneels L, Willard FH. The sacroiliac joint: an overview of its anatomy, function and potential clinical implications. J Anat. 2012;221(6):537-567. doi:10.1111/j.1469-7580.2012.01564.x
4.. MRI Appearance of Chronic Stress Injury of the Iliac Crest Apophysis in Adolescent Athletes. Kenneth J. Hébert, Tal Laor, Jon G. Divine, Kathleen H. Emery, and Eric J. Wall. American Journal of Roentgenology. 2008 190:6, 1487-1491
5.Verstraete EH, Vanderstraeten G, Parewijck W. Pelvic Girdle Pain during or after Pregnancy: a review of recent evidence and a clinical care path proposal. Facts Views Vis Obgyn. 2013;5(1):33-43.
6.Allegri M, Montella S, Salici F, et al. Mechanisms of low back pain: a guide for diagnosis and therapy. F1000Res. 2016;5:F1000 Faculty Rev-1530. Published 2016 Jun 28. doi:10.12688/f1000research.8105.2
7.Wernecke C, Braun HJ, Dragoo JL. The Effect of Intra-articular Corticosteroids on Articular Cartilage: A Systematic Review. Orthop J Sports Med. 2015;3(5):2325967115581163. Published 2015 Apr 27. doi:10.1177/2325967115581163
8.Lee JJ, Harrison JR, Boachie-Adjei K, Vargas E, Moley PJ. Platelet-Rich Plasma Injections With Needle Tenotomy for Gluteus Medius Tendinopathy: A Registry Study With Prospective Follow-up. Orthop J Sports Med. 2016;4(11):2325967116671692. Published 2016 Nov 9. doi:10.1177/2325967116671692. iliac crest pain