Iliotibial Band Syndrome (ITBS) is an overuse injury seen in runners, cyclists, soccer players, skiers, and weightlifters. ITBS is one of the most common causes of lateral knee pain. This condition often never completely resolves with conventional treatments, since most practitioners do not typically address all of the key structures involved in this injury.
Traditionally ITBS is seen as a friction syndrome in which the iliotibial band rubs against the lower portion of the leg (lateral femoral epicondyle of the femur). It has been postulated that this occurs when the iliotibial band moves anterior and posterior during knee flexion and extension. This repetitive motion causes friction, micro-tears, and inflammation of the area. (including a bursa located between the lateral epicondyle and the IT band).
Numerous researchers have demonstrated that the most intense pain is experience at about 30 degrees of knee flexion (a zone of impingement). This is certainly the perspective I was taught during my orthopedic classes 25 years ago. It is also the logic that most practitioners use to formulate a treatment strategy. The only problem is that this perspective is WRONG….
What the Research is Telling Us
With recent research, this traditional perspective has definitely come into question. This is primarily due to the discovery of anatomical factors that actually prevent the iliotibial band from moving in an anterior-posterior direction. Research has demonstrated that the iliotibial band is actually firmly anchored to the leg (linea asperaof the femur) by a sheet of strong connective tissue (intermuscular septum). (1)
In addition it is also attached by strong fibrous strands just above the knee (lateral epicondyle) and deep into the bone. These strong attachments prevent the iliotibial band from sliding anterior and posteriorly over the lower leg (lateral epicondyle) as was previously assumed.
Anatomy and Function of the ITB
Anatomically, the iliotibial band (ITB) is a thickening of a structure known as the fascia lata. The fascia lata is a web of connective tissue (fascia) that completely covers your entire leg. Think of the fascia lata as a sock encasing your entire thigh. The iliotibial band (the fascial thickening) is located on the lateral aspect of your thighand is not an independent structure; it is a fully integrated part of the fascia lata. Which makes the postulated anterior-posterior motion pretty much impossible since it cannot glide independently.
The Iliotibial band is also part of a structure called the “Pelvic Deltoid Complex”.
In this complex, the superficial layers of the gluteus maximus muscle from the posterior hip and the fibers from tensor fascia latamuscle at the front of the hip fuse into the Iliotibial band. These muscles collaborate with each other to raise the hip to the side (abduct the hip). They also assist the gluteus medius muscle (an abductor) in maintaining the pelvis in a neutral position when standing on one leg (Stance Phase of Gait).
In addition the IT band acts as a brace that decreases bending stresses on the leg (femur). It does this by converting tensile loading to compressive loading on the lateral aspect of the leg.
Gait Cycle: Want to learn more about the different phases of the gait cycle? Read Dr. Abelson's blog "Designed to Run - The Human Gait Cycle".
Look at Hip Strength! Not the IT Band Length
When the muscles of the hip become weak, there is an increase in the inward motion (adduction) of the leg. This becomes evident during the Stance Phase of Gait. This inward motion increases the amount of force directed through the iliotibial band, which in turn causes compression of the tissue of the lateral knee.
This is exactly what researchers have found in individuals who suffer from ITBS. ITBS sufferers have weak gluteal muscles (abductors) and an increase in inward motion (adduction) of the hip during the Stance Phase of Gait. (2)
The Problem Lies in the Fat Pad, Not in the Bursa
Earlier, we mentioned that the conventional perspective believed compression of the bursa is the cause of the pain. (A bursa is a fluid filled sac found between anatomical structures). Unfortunately MRI studies have shown that there is no bursa between the IT band and the lateral knee. From a biomechanical perspective, there are no bursa in this area because there is no need for one. Without the presumed anterior-posterior motion, there is no need for reduced friction.
However is in the area between the IT band and lateral knee (the site of pain), there is a layer of highly innervated fat, a layer of fat full of neurological receptors. Compression of this area is the most likely cause of the lateral knee pain in Iliotibial Band Syndrome. (4)
Treatment of ITBS
This new information should change a practitioner approach for treating ITBS. Clinically I have found that excellent results can often be achieved in even the most stubborn cases.
ITBS Video: Check out our video on ITBS, Just click the image to right. We produced this video several year back. Still lots of great information, but we have learned even more with all the new research that has come out since then!
Running and the Iliotibial Band
I want to make a few points about the the function of the IT Band and Running. Some of the amazing features of the the ITBand are:
That it work as incredibly effective "Swing Spring". The IT Band helps you store and release energy for forward propulsion. In fact “the human IT band has the capacity to store 15 to 20 times more elastic energy per body mass" than other primates such as the chimpanzee. (5)
It assists the gluteus medius muscle in preventing the pelvis (contralateral pelvis) from dropping. (3)
It decreases leg pressure (femoral pressure) through the bowstring effect. The IT Band is connected directly to the femur (intermuscular septum). As the lateral quadricep expands (vastus lateralis) on loading (stance phase of gait) a bowstring effect is created. This bowstring effect is in essence a strong brace which decreases strain on the femur. (3)
DR. BRIAN ABELSON DC.
Dr. Abelson believes in running an Evidence Based Practice (EBP). EBP's strive to adhere to the best research evidence available, while combining their clinical expertise with the specific values of each patient.
Dr. Abelson is the developer of Motion Specific Release (MSR) Treatment Systems. His clinical practice in is located in Calgary, Alberta (Kinetic Health). He has recently authored his 10th publications which will be available later this year.
Is iliotibial band syndrome really a friction syndrome?Fairclough J, Hayashi K, Toumi H, Lyons K, Bydder G, Phillips N, Best TM, Benjamin M J Sci Med Sport. 2007 Apr; 10(2):74-6; discussion 77-8.
Hip abductor weakness in distance runners with iliotibial band syndrome.
Fredericson M, Cookingham CL, Chaudhari AM, Dowdell BC, Oestreicher N, Sahrmann SA Clin J Sport Med. 2000 Jul; 10(3):169-75.
Fairclough J, Hayashi K, Toumi H, et al. The functional anatomy of the iliotibial band during flexion and extension of the knee:implications for understanding iliotibial band syndrome. J Anat. 2006;208:309-316
The functional anatomy of the iliotibial band during flexion and extension of the knee: implications for understanding iliotibial band syndrome J Anat. Mar 2006; 208(3): 309–316.
The Harvard Gazette - "Understanding the IT Band"
Dr. Abelson is the owner of Kinetic Health, a partner in BKAT Motion Specific Release, and a partner in Rowan Tree Books.