However, there are lots of misconceptions around this truly remarkable piece of our anatomy. One of the misconceptions is that the ITB itself is the cause of the problem. This is not true, as the ITB is not a contractile structure like a muscle. Rather, the ITB is comparable to a seat belt in its structure and tensile properties. It functions both as a lever for knee actions and, mostly, as a strut or support for both the hip and knee – kind of like a guy-rope of a tent.
Anatomy
The anatomy of the ITB is interesting, as it is made of connective tissue and resembles a blend of a tendon and a band of fascia. It starts from the musculotendinous junction of the Tensor Fascia Latae (TFL) muscle, extends down the side of the thigh and attaches to a projection on the side of the tibia (shin bone) called Gerdy’s Tubercle. The TFL starts on the front of the outside of the ilium in the pelvis/hip region and extends to the ITB. The TFL performs abduction and flexion at the hip, tilts the pelvis anteriorly (forwards) and internally rotates a flexed hip.
Along with the TFL, the Gluteus Maximus (Glute Max) acts on the ITB to support and perform actions at the knee and hip. The Glute Max is the largest of the gluteal muscles; it starts on the back of the outside of the ilium, sacrum, coccyx and lumbar fascia, and runs to the greater trochanter of the femur and the ITB. The Glute Max performs the movements of extension and external rotation of the hip, as well as tilting the pelvis posteriorly (backwards). Because the Glute Max is a large muscle, the fibres divide into two sections and travel at slightly different angles; this creates a 2-in-1 effect in the muscle. The upper fibres perform abduction of the hip/leg and the lower fibres perform adduction of the hip/leg.
Shortening or tightening of the TFL or Glute Max will cause the ITB to tighten as well, which causes postural changes to occur. If the TFL is causing the tightening of the ITB, it pulls the pelvis into an anterior (forward) tilt. An anterior tilt of the pelvis causes an increased lordosis or curve in the low back. If the Glute Max is causing the ITB to tighten, the pelvis is pulled into a posterior (backward) tilt. A posterior pelvic tilt causes a flat low back or slouching posture. Both of these incorrect postures can cause low back pain and other postural problems.
Iliotibial Band Friction Syndrome
ITB Friction Syndrome (ITBFS) is a painful condition felt at the knee. It is often described as a burning, aching or tenderness on the outside of the knee, and can be accompanied by a snapping or popping sound. The pain usually occurs on bending or straightening the knee. ITBFS is usually caused by a biomechanical dysfunction at either the bones or muscles.
ITBFS is caused when the ITB is pulled too tight by muscular imbalances of the TFL and Glute Max, or by bony deformity, usually at the knee. The taut ITB then creates increased friction as it moves over the lateral femoral condyle (a bony protrusion on the femur above the knee) during bending and straightening of the knee. A naturally occurring bursa is present to prevent injury to the ITB from a normal friction load; however, as the load increases, the bursa is unable to perform its function and becomes inflamed.
The inflammation of the bursa and tendon is what causes the pain, and can also cause redness and swelling when severe. The snapping or popping sound that can occur is caused by the taut ITB flicking over the lateral femoral condyle – kind of like flicking a guitar string.
Common Causes of ITBFS
- Bow legs
- Osteoarthritis of the knee
- Leg length discrepancy
- Muscle weakness in the abdominal canister, gluteals and the hip
Sports and activities that involve repetitive flexion and extension of the knee are prone to causing ITBFS. These sports include running, cycling, hiking, long-distance walking and other activities like CrossFit.
ITBFS is easily treatable and preventable without surgical intervention.
Tips to Prevent ITBFS
- A good warm-up, cool-down and stretching regime
- Incorporating sufficient recovery time into your weekly exercise regime
- Wearing the correct shoes for your feet
- Running on a flat surface or alternating the side of the road you run on. Most roads have a camber or tilt, so one leg will always work harder than the other, causing muscle imbalances.
- Foam rolling – for endurance sports such as long-distance running, cycling and triathlons, this is an important part of a recovery regime
- Get a running analysis
- Get a biomechanical analysis
ITBs are wonderful support structures that literally strut the hip and knee while you strut your stuff, be it in the mall or on the run. It’s important to remember that problems at the ITB are only the indication of a problem elsewhere that needs to be addressed. If you are concerned that you might have ITBFS, or are participating in a high-level sport that involves repetitive motions at the knee, please contact your physiotherapist for treatment and assessment.
Prevention is always better than cure, and the quicker you deal with the problem, the quicker you can be back to confidently strutting your stuff pain-free!