The Infamous IT Band


The IT band (iliotibial) is probably the most common dysfunction I treat in my clinic. It is the leading cause of pain in the knee for distance runners (Noehren, Davis, & Hamill, 2007). Why is it so problematic? Let’s start with describing the structure. The IT band is a strip of connective tissue that originates in the iliac tubercle which is the widest point of your pelvis (Sher et al., 2011). It then converges with the fibers of the TFL (tensor fascia latae) and gluteus maximus, inserting on the anterior aspect of the lateral epicondyle of the tibia (Gerdy’s tubercle). It is avascular and made of collagen and fibroblasts. It is dense, thick, and feels like leather. There is a small degree of elasticity to it due to a small percentage of elastin protein fibers. The muscles that converge with it act to abduct, extend, flex, and rotate the hip. So basically it is involved in all movements of the hip besides adduction, where it is passively tensioned. With knee flexion, the distal fibers tension posteriorly. With knee extension, the fibers tension anteriorly. In other words, it is involved in basically all movements of the hip and knee, and the avascularity means it repairs slowly. The perfect storm of overuse.

WHAT IS IT, EXACTLY?

It has been classically called IT band friction syndrome. The theory was that the IT band was rubbing back and forth over the lateral epicondyle of the femur causing a bursa to inflame. Recent cadaveric studies have revealed that a bursa in this area probably does not exist. Additionally, the IT band is not free-floating; it is connected to the femur with an intermuscular septum with thick fibrous bands. The idea of friction may be an illusion as the anterior and posterior fibers change in tension. It may be that they compress a highly innervated and vascularized layer of loose fat and connective tissue (Fairclough et al., 2007).

What is the mechanism of the injury? One common cause is thought to be due to weakness in the hip abductors. I should say relative weakness. I have made the mistake of manually muscle testing hip abduction and found normal strength on both sides. Well there is limitation to our ability to sense discrepancies from the left hip to the right hip when testing with our hands. Just because strength on both sides is 5/5 (normal) with our manual testing, does not mean that it is truly equal and does not necessarily mean that the hip abductors are being recruited in equally and appropriately in functional activity such as jumping and running. One study used a dynamometer and found that long distance runners had a 2% difference in hip abductor strength with the affected leg being weaker (Fredericson et al., 2000). That level of difference is too subjective and subtle to detect. In the average person, this doesn’t become problematic because we are not pressing our body to its outer limits. However, a triathlete that spends much of their waking life running, will tease out that small difference. Suddenly that 2% difference rises to the surface and becomes crippling.

Lending to this idea of weak hip abductors, another study found that compared to a control group, runners with IT band syndrome had greater moments of hip adduction and knee internal rotation (Noehren, Davis, & Hamill, 2007). When the foot lands, the hip abductors have to eccentrically contract to avoid excessive hip adduction. If they are unable to do this or if they fatigue, other structures will have to compensate causing the IT band to compress against the lateral epicondyle of the femur, creating soft tissue and myofascial restrictions (Fredericson & Wolf, 2005).

There is some evidence that suggests the hamstring may be a missing piece of this puzzle. The hamstring has a role in stabilizing the knee in foot strike. The hamstring acts to posteriorly glide and externally rotate the tibia, changing the position of the lateral epicondyle and the patella (Kwak et al., 2005). Which makes sense; runners that internally rotate the knee are at increased risk.

The degree of knee flexion at foot strike counts as well. Biomechanical studies have revealed the maximum compression of the IT band on the lateral epicondyle occurs at 30 degrees of knee flexion (Fredericson & Wolf, 2005). This may explain why running downhill increases the likelihood of developing IT band pain, as the degree of knee flexion changes in downhill running. Other risk factors include a sudden increase in normal weekly running, and running the same direction on a track (Fredericson & Wolf, 2005).

PROGNOSIS

Irritation of the IT band takes much longer to reduce compared to a muscle due to the lack of blood supply. Finding the underlying mechanism is the key to long term recovery. Taking time off from the provocative activity (i.e. running) will reduce and likely eliminate the pain. However, if the mechanism is not uncovered and treated, the pain will return. When it comes to the traditional recommendation of stretching, it seems to rarely help. The IT band is not a true contractile tissue so it follows that stretching it will not do much. At most, we may just be stretching the gluteus muscles. Another reason I avoid stretching it is that I find a lot of patients with IT band syndrome have a blossoming greater trochanteric bursitis. Placing the leg into adduction is going to compress the bursa into the hip further. So I use soft tissue techniques to reduce pain and possibly improve the sliding surfaces. Anecdotally, I find that strengthening the gluteus medius and working on mechanics of stepping/striding with avoidance of femoral internal rotation to be invaluable. In one study, runners that enrolled in a 6 month protocol that targeted the strength of gluteus medius were able to improve torque in the gluteus medius between roughly 30-50% and were pain free (Fredericson et al., 2000). When the athlete returns to sport, it is crucial to educate on activities to avoid, namely downhill running and running in the same direction on a track. It seems counter-intuitive, but faster paced running is less likely to aggravate the IT band compared to slower paces (Fredericson & Wolf, 2005). In sprinting, the knee is flexed beyond the 30 degree angle that tends to aggravate the tendon (Orchard, Fricker, Abud, & Mason, 1996). The IT band can be frustrating for the both the patient and the therapist, but I find that education of expected outcomes and patience are crucial.




References:

Noehren, B., Davis, I., & Hamill, J. (2007). ASB Clinical Biomechanics Award Winner 2006. Clinical Biomechanics, 22(9), 951-956. doi:10.1016/j.clinbiomech.2007.07.001

Sher, I., Umans, H., Downie, S. A., Tobin, K., Arora, R., & Olson, T. R. (2011). Proximal iliotibial band syndrome: What is it and where is it? Skeletal Radiology, 40(12), 1553-1556. doi:10.1007/s00256-011-1168-5

Fairclough, J., Hayashi, K., Toumi, H., Lyons, K., Bydder, G., Phillips, N., . . . Benjamin, M. (2007). Is iliotibial band syndrome really a friction syndrome? Journal of Science and Medicine in Sport,10(2), 74-76. doi:10.1016/j.jsams.2006.05.017

Fredericson, M., Cookingham, C. L., Chaudhari, A. M., Dowdell, B. C., Oestreicher, N., & Sahrmann, S. A. (2000). Hip Abductor Weakness in Distance Runners with Iliotibial Band Syndrome. Clinical Journal of Sport Medicine, 10(3), 169-175. doi:10.1097/00042752-200007000-00004

Fredericson, M., & Wolf, C. (2005). Iliotibial Band Syndrome in Runners. Sports Medicine, 35(5), 451-459. doi:10.2165/00007256-200535050-00006

Kwak, S. D., Ahmad, C. S., Gardner, T. R., Grelsamer, R. P., Henry, J. H., Blankevoort, L., . . . Mow, V. C. (2000). Hamstrings and Iliotibial Band Forces Affect Knee Kinematics and Contact Pattern. The Journal of Bone and Joint Surgery-American Volume, 82(11), 32. doi:10.2106/00004623-200011000-00043

Fredericson, M., Cookingham, C. L., Chaudhari, A. M., Dowdell, B. C., Oestreicher, N., & Sahrmann, S. A. (2000). Hip Abductor Weakness in Distance Runners with Iliotibial Band Syndrome. Clinical Journal of Sport Medicine, 10(3), 169-175. doi:10.1097/00042752-200007000-00004

Orchard, J. W., Fricker, P. A., Abud, A. T., & Mason, B. R. (1996). Biomechanics of Iliotibial Band Friction Syndrome in Runners. The American Journal of Sports Medicine, 24(3), 375-379. doi:10.1177/036354659602400321


Christopher EllisComment