Friday, February 10, 2012

Injury Series: Biomechanical solutions for iliotibial band (IT band) syndrome / ITBS

It's been a while since we've thoroughly reviewed an injury, so today we'll be looking at another one of the "big five" most common running injuries.  We've already seen how treatment for Achilles tendonitis has been revolutionized by specific eccentric exercises to remodel damaged tendon collagen; today's topic is iliotibial band syndrome, sometimes also referred to as (erroneously, it seems) iliotibial band friction syndrome.  It is one of the most common running injuries and seems to be a problem both for recreational runners and for elites, accounting for somewhere between 8 and 10% of all injuries, depending on the study (Marti et al., Taunton et al.)  Unfortunately, it's sometimes misunderstood, and there's a good bit of evidence indicating that current treatments centered around stretching, tissue manipulation, and anti-inflammatory drugs are incomplete.  As usual, we'll go over some basic anatomy and terminology first, then delve into what the scientific literature has to say about this injury.  Like before, I'll also include some common "tricks" runners use to overcome IT band problems, but I'll make it clear what's science and what's hocus-pocus magic.

Anatomy

The iliotibial band, commonly abbreviated as the "IT band," is a long, thick band of connective tissue (most properly referred to as a thickening of the leg muscle fascia) that serves to connect many of the major hip extensors and abductors (gluteal muscles and the tensor fasciae latae muscle) to the lower leg.  More specifically, it connects to the tendons of the gluteus maximus, the main hip extensor, and the tensor fasciae latae (TFL—a short, straplike muscle that runs between the top of your pelvis and your femur), a hip stabilizer and abductor, to the top of the tibia, just below the knee.  As such, it also helps stabilize and control the knee joint in addition to the hip.  Most relevant for runners, it seems to stabilize the hip and knee at footstrike.

As you can see to the right, the IT band runs parallel to the quadriceps muscles and hamstrings.  The black arrow points to the most common location of pain: the outside of the knee, just above the knee joint.  However, this is not the only location of pain: sometimes ITBS can manifest itself higher up on the band, along the thigh or even near the greater trochantor of the femur.  Regardless, the vast majority of ITBS cases involve significant pain on the lateral knee.

This location was widely assumed to be irritated by a small bony protrusion on the femur, called the lateral femoral epicondyle, illustrated to the left.  The lateral epicondyle is fairly easy to feel by hand, and indeed the IT band appears to slide across the epicondyle during knee flexion.  IT band pain is usually worse when the knee is at approximately 20-30 degrees of flexion, adding to the theory that the cause of IT band pain is friction between the IT band and the lateral femoral epicondyle—hence the name "iliotibial band friction syndrome."  However, recent research, MRI imaging, and cadaver studies have called this assumption into question: in 2006 and again in 2007, Fairclouth et al. demonstrate rather convincingly that, as the IT band is really no more than a thickening of the fascia latae, which envelopes the entire musculature of the lateral leg and indeed is firmly attached to the femur near the epicondyle by thick, fiberous issue; it is not anatomically possible for the IT band to "slide" over the epicondyle as if it were a "free" structure like a tendon or ligament.  But why is the IT band usually irritated over the lateral epicondyle, and why do patients sometimes respond to cortisone injections in the area? Fairclouth et al. propose that the tissue between the lateral epicondyle, which is comprised of fatty tissue rich in blood vessels and nerve endings, gets compressed by the IT band during running, particularly when the knee is at 20-30 degrees of flexion.  While this is interesting in an academic sense, does it really matter to a runner who's got IT band problems?

Interestingly, it may: the distinction between compression instead of friction of the fatty tissue between the IT band and the bony protrusion on the femur may hold the key to its origins.  If it was merely a friction issue, it seems that the solution would be fairly mundane: ice, rest, lower volume in training.  But some interesting research in the last decade or so has elucidated an interesting possibility: the nerve endings in the fatty tissue between the IT band and the femur, called Pacinian corpuscles, function as proprioceptive feedback units, giving the brain information about what's going in in and around the body.  This will become important when we return to the biomechanical origins of IT band problems, so don't forget about this fatty tissue and the nerve endings within!


Symptoms and Epidemiology

As mentioned above, iliotibial band sydrome accounts for somewhere in the neighborhood of one in ten of all running injuries.  Unlike some issues, IT band problems seem to affect runners at all levels of competition, from recreational runners to elites.  Classically, IT band syndrome begins as a sharp or burning pain on the outside of the knee which occurs after a few miles of running.  When aggravated, it may eventually become painful with daily activities like walking or descending and ascending stairs. Sitting for a long time also tends to aggravate the IT band, since (as mentioned above) the compression of the fatty tissue above the lateral epicondyle is strongest at 20-30 degrees of knee flexion.  Runners find their pain is often greater while running downhill, since again, knee flexion increases during downhill running (not to mention impact forces).  

Interestingly, a few sources claim that the IT band is actually less stressed by faster running, since the knee is less flexed at footstrike.  While this makes intuitive sense, I suspect that part of this benefit is offset by the significantly greater impact forces created while running fast vs. jogging, so I am very hesitant to recommend (as some do) starting back running from IT band syndrome with short bursts of fast strides interspersed with walking, but if you are feeling particularly confident in theoretical biomechanics, you might consider giving it a shot.

What are the causes of IT band problems? A popular website lists the following as the "most common causes of ITBS" (with no sources cited I might add):
  1. Leg length differences
  2. Road camber - running on a slope for a long time
  3. Foot structure
  4. Excessive shoe breakdown - particularly it the outside of the heel
  5. Training intensity errors - increasing mileage or intensity too fast
  6. Muscle imbalances - particularly quads versus hamstrings
  7. Run/gait style factors - e.g. bow-leggedness, knock knees, etc.
Other ideas that are floated at some point or another include running on tight turns, excessive downhill running, or running on hard surfaces.  The problem is that none of these have much (or in some cases, any) scientific evidence to back them up.  There haven't been any rigorous studies that have connected any of these factors (except for 'training errors') with IT band injuries.  And even the "training errors" theory isn't helpful—presumably, something went wrong biomechanically speaking, otherwise you would have injured another structure first.  What made your IT band the weakest link in the chain?

To answer that, we have to look at the scientific literature.  First, though, I should note that you shouldn't discredit factors like road camber, old shoes, excessive downhill or indoor track running, and so on.  You may find for your particular case of ITBS, they may be a factor, but they aren't universally recognized.  To that end, newer shoes, more varied running surfaces, and so on are never bad ideas.  Some of the other factors, though, like trying to correct leg length discrepancies, may be more risky. 

Turning to the science, here's the spoiler: the single most important factor in predicting and possibly treating IT band problems is hip abductor strengthHere's a review if you've forgotten what abduction is.  To start, we'll look at some retrospective studies.  These are the most simple kinds of investigations into an injury's root cause: you gather a group of runners with a particular injury, examine their gait, muscular strength, training habits, and so on to see if you can find anything in common.  If so, you can then compare these results to a matched group of healthy runners to see if there is a difference between the groups.  While it's easy to see why this alone doesn't prove a cause-effect relationship, it's a good first step in uncovering one.


Hip strength and ITBS

In 2000, Michael Fredericson and his colleagues at Stanford University published such a study.  It examined 24 distance runners with ITBS, measured their hip abduction strength, and compared it to that of healthy runners.  The injured runners were found to have significantly weaker hip abductors on their injured side compared to the healthy side, and were also found to have weaker hip abductors on both sides compared to healthy runners.  The test for hip abductor strength was an isometric strength test, where the subjects were asked to abduct their hip as "hard" as possible against a dynamometer.  While not identical to the kinds of stresses put on the hip during running, the abductors do work isometrically during the stance phase to hold the pelvis straight.



A classic sign of weak hip abductors is the trendelenburg gait, where the hips "drop" towards the unsupported side while running.  As is illustrated on the left, a "drop" in the hips will necessarily require the stance phase leg to be adducted (moved towards the centerline of the body) moreso than if the hips were not "dropped."  Since the IT band is essentially a thick strap of tissue that runs along the outside of the leg, it would not be a stretch (no pun intended) to propose that increased hip adduction increases strain on the IT band.  And in fact, two studies confirm this (Ferber et al. and Noehrer et al.).  The first, conducted by Irene Davis' lab (no relation) at the University of Delaware, measured hip, knee, and ankle biomechanics in two groups of healthy runners.  One group had never had ITBS, while the other had previously been diagnosed with ITBS but had recovered.  The subjects ran overground through an array of 3D cameras which tracked the motion of their legs.  Using computer software, Davis and colleagues measured the motion of the ankle, knee, and hip joints during the gait cycle.  The results were in line with what we'd expect based on our simple model above.  Increased hip adduction and knee internal rotation (which would also logically increase strain on the IT band) were associated with a history of ITBS.  In their own words:
However, aside from this variable [an increase in rearfoot inversion moment], these results begin to suggest that lower extremity gait mechanics [i.e. foot and ankle] do not change as a result of ITBS. Moreover, the similar results of the current study [...] suggest that the aetiology of ITBS is more related to atypical hip and knee mechanics as compared to foot mechanics. Therefore, the current retrospective study provides further evidence linking atypical lower extremity kinematics and ITBS. (Ferber et al.)
Interestingly, it seems that people who've suffered ITBS seem to pronate less than those who have not—probably ruling out "pronation correction" as a viable treatment option.  More importantly, this study highlights that hip and knee mechanics are an important part of IT band issues.  But did these changes in biomechanics happen because the runner became injured? Would we be able to predict who might get ITBS if we evaluated a group of completely healthy runners , then waited and observed who got hurt?

Irene Davis' group attempted to answer that question with a 2007 prospective study (Noehren et al.) which was designed as described above: a group of healthy female runners had their running mechanics evaluated using the same overground 3D camera system as above, and over the course of two years, they were followed via email.  Some eighteen runners (out of 400 total evaluated at the outset of the study) developed ITBS during the study.  When compared with a group of control subjects who remained healthy, the same tendencies were seen: the runners who would later develop ITBS exhibited differences in hip adduction and knee internal rotation.  The knee, being a hinged joint between the tibia and femur, can be driven to internally rotate in one of two ways: either the tibia can internally rotate or the femur can externally rotate.  Surprisingly, the tibial internal rotation in the injured runners was less than in the healthy group.  The net knee internal rotation came entirely from femoral external rotation.  Noehren et al. note that the main internal rotators of the femur (i.e. the muscles which should prevent femoral external rotation) are the tensor fasciae latae, the gluteus minimus, and the gluteus medius, which make up the hip abductor muscle group.  It was this very same muscle group which was weakened in runners with ITBS in the Stanford study! A doctoral thesis by Alison Brown at Temple University also investigated muscle strength in runners with and without ITBS; interestingly, she found no difference in maximal strength, but a significant difference in endurance.  Clearly, hip abductor strength plays a major biomechanical role in the development of ITBS.   

Furthermore, John Fairclough's anatomical work on the iliotibial band (discussed above) suggests that the Pacinian corpuscles (a type of pressure-sensitive nerve ending) in the fatty tissue underneath the IT band as it crosses the knee are supposed to prevent excess strain on the IT band.  In a healthy runner, the compression of the Pacinian corpuscles by the IT band triggers the hip abductor muscles to fire, reducing strain on the IT band by avoiding excessive hip adduction. But this protective mechanism fails when the main hip abductor muscles are dysfunctional or weak, as he explained to me via email:
The feed back [i.e. compression of the Pacinian corpuscles deep to the IT band near the epicondyle] should stimulate the Gluteus Medius, etc. to fire and stop the pelvis from adduction moment.  If however there is an incompetence of the Abductors, mainly G. Medius, then the only major muscle to stop adduction is the Tensor Facia Lata of which the ITB is a part.  It can resist abduction forces but is not designed to do so and hence it will over compress the distal tissues which is why on MRI often the fat pad [deep to the IT band] looks oedematous [read: swollen and damaged].
Using data from her lab's prospective study, Irene Davis created a computerized model of the stresses the IT band undergoes during running.  Given a standard anatomic model of the skeleton, Davis and her colleges plugged in data about joint motion and impact forces (much like Dr. Casey Kerrigan's study I critiqued a few weeks ago) and computed how various biomechanical factors affected the strain (note I'm using "strain" loosely here; I really mean strain rate) on the IT band (Hamill et al.).  As predicted, the computer model showed that the runners who went on to develop IT band syndrome displayed an increased strain rate on their IT band—moreover, the computer model was able to predict which side they would injure, as the model's data output showed a significant side-to-side difference in the injured runners (the injured side, of course, taking on more strain than the uninjured side).  Runners who remained healthy showed no asymmetries in side-to-side IT band strain.  While the model did not show a particularly strong connection between hip adduction, knee internal rotation, and strain rate, I suspect this was result of an unavoidably-imperfect and incomplete computer model. 

At this point, the evidence overwhelmingly points to a biomechanical fault in the abductor muscles of the hip as the root cause for IT band syndrome.  Weak or misfiring gluteus medius, gluteus minimus, or tensor fasciae latae muscles are unable to control the adduction of the hip and internal rotation of the knee, leading to abnormal stress and compression on the IT band.  This muscular dysfunction manifests as excessive hip adduction and knee internal rotation, both of which increase strain on the iliotibial band and compress it against the fatty tissue between the lateral femoral epicondyle and the IT band proper, causing abnormal stress and damage. But although the pain is coming from the lateral knee, the root of the problem is coming from the hip muscles.

Biomechanical solutions for a biomechanical  problem

Fredericson et al. 2000. Healthy runners avg. 9.7-10.2
This brings us back to Michael Fredericson's 2000 Stanford University study.  Unlike many retrospective examinations of injuries, his study took the additional step of prescribing a six-week strengthening and stretching program.  While the usefulness of stretching is questionable (see below), a strength program for rehabilitating the hip abductor muscles is, scientifically speaking, the most sound long-term solution to IT band syndrome.  Unfortunately, there hasn't yet been a randomized, controlled trial of runners with ITBS—Fredericson's study didn't even have a control group! But his results were indeed impressive: following the six-week protocol consisting of two stretches and two strength exercises, 22 of the 24 athletes (92%) in the study returned to running.  Additionally, their hip strength improved markedly: their strength values after rehabilitation were comparable with healthy runners who did not have ITBS (see figure to right).  Is this the randomized clinical trial we need to "prove" the efficacy of hip abductor strengthening exercises? No.  But, combining this with the reams of indirect evidence indicating hip abductor weakness as a major factor in the development of ITBS, am I comfortable recommending hip strength exercises as the prime choice for rehabilitation and prevention? Yes.

The following is the program that Fredericson et al. prescribed to their subjects in 2000.  It's by no means perfect, and I have some suggested additions which I'll present separately, but currently it's the closest we have to an "approved" hip abductor strength program that's been evaluated in the scientific literature:


The Fredericson Protocol for ITBS:

The exercises prescribed by Fredericson et al. are illustrated below.  The stretches, denoted (1) and (2), were performed three times per day, 15 seconds each on both sides.  The strength exercises, denoted (3) and (4), started at one set of 15 repeats once per day and built by 5 repeats per day, assuming there was no soreness from the previous day, up to three sets of 30 repeats once per day.  The program lasts six weeks.  Additionally, nonsteroidal anti-inflammatories (presumably Advil, Aleve, or similar) were prescribed for the first week or so, until pain with daily activities disappeared.

Click for larger image
The athletes were instructed to avoid running for the six-week rehab program, though they could cross-train if it did not cause pain.  As mentioned earlier, 92% of the athletes in the study recovered after this rehab period (though the lack of a control group makes it impossible to say why they got better: the 6 weeks' rest, the hip strength, the stretching, or the anti inflammatories!).

Recommended additions to the Fredericson protocol

I recommend doing three additional exercises for hip strength.  Two of these I got from Dr. Rob Johnson, an orthopedist and practitioner in the Twin Cities (who incidentally authored one of the first major studies connecting hip muscle weakness to running injuries), and the third I got from a physical therapist in the Twin Cities area.  I think these three are important additions because the Fredericson protocol lacks any external rotation component (hence the "clamshells") and also lacks any isometric exercises (hence the glute bridge and wall press).  While the wall press doesn't carry the "stamp of approval" of any published researchers I know of, I doubt it'll be highly controversial—if you don't trust me, then axe these ones and just do the above protocol.  For lack of anything better, you can start with 1x15 and build to 3x30 with these strength exercises as well.

Adopted from mckinley.illinois.edu/handouts
*Clamshell leg lifts
Very similar to side leg lifts (exercise 3 in the Fredericson protocol), but the knees are bent, meaning your legs "open" like a clam, externally rotating instead of simply abducting.  As with the side leg lifts, go slowly and ensure the hips are straight above each other, not tilted forward or backwards.
Adopted from uptownwomenscenter.com/topics/
*Pelvic tilt into glute bridge, 5sec hold at top
This exercise is done lying on your back with your knees bent.  "Tilt" your pelvis up by drawing your stomach in, then, keeping your pelvis "up," use your glute muscles to go into what's called a "glute bridge" and hold it for 5sec, then lower back down and "untilt" your pelvis.
adopted from mikereinold.com
*Isometric wall press 15x5sec
Stand perpendicular to a wall, with your shoulder, hips, and foot against it.  Raise your inside leg up so your thigh is parallel to the ground and your knee is bent at 90 degrees (like you were stepping up onto a bench).  Then use that raised inside leg to push against the wall.  You should feel it in your glutes on the OUTSIDE leg as it resists (isometrically) the pressure from your inside leg/the wall. 

Other treatments: stretching, rolling/manipulation, and more

Hip abductor strength is by far the most scientifically supported treatment for ITBS, but most doctors, trainers, and physical therapists will recommend stretching, rolling/manipulation, or both in addition (and unfortunately, sometimes instead of) hip abductor strength training.  The evidence for these treatments is much more limited and their utility is much-debated among the research community.

While it's often reported that the IT band is "as strong as soft steel" (and is thus impossible to stretch), this is a bit of a mischaracterization.  From what I can tell, that statement comes from a 1931 paper (Murray) which investigated the tensile strength of the fascia lata, the sheath that envelops the lateral muscles of the thigh (recall that the IT band is simply a thickening of this tissue).  Indeed, the fascia lata shows a tensile strength of about 7800 psi (54 MPa in metric), which is comparable to a strong plastic or a soft metal.  But this is the ultimate strength of the fascia lata—the point at which it breaks! Inside the body, it's reasonable to expect that it ought to remain in the elastic portion of its stress-strain diagram.  The fascia lata stops behaving elastically (i.e. returning to its original dimensions after being stretched) at about 2200 psi, more in line with your average plastic or hard rubber.  Either way, the fascia lata appears to be at least somewhat "stretchy."  Whether stretching actually accomplishes anything is another issue.

In an actual experiment which involved performing IT band stretches on fresh cadavers with microstrain gauges implanted into the IT band (surely a riveting endeavor!), Falvey et al. report that the IT band itself is not particularly amenable to stretching, but mostly due to its numerous attachments to the femur, not its stiffness.  Instead of focusing on the IT band itself, Falvey et al. recommend stretching or manipulating the main muscles which control the tension on the IT band—the tensor fasciae latae and the gluteus maximus:
The longitudinal and firm attachment (0.3mm average thickness) of the ITB to the full length of the femur means that the potential for physiological lengthening is limited [...] These findings highlight the tensioning role of gluteus maximus (working synergistically with TFL) in ITBS, concurring with other studies noting the substantial contribution of gluteus maximus to the ITB [...] The anatomical evidence for the current treatment regimens discussed previously [stretching the IT band and eliminating inflammation over the lateral femoral epicondyle] appears insufficient. While local treatment measures may have role in temporarily easing  symptoms, they appear to treat symptoms rather than cause. Given that it appears that the muscular  component of the complex plays an important role in tensioning of the ITB, treatment should be directed at TFL and gluteus maximus.  
So presumably, any stretching should be directed at the tissue surrounding the IT band, not the IT band itself.  I'm no expert on stretching, but it's easy to prove to yourself that stretch number (1) from the Fredericson protocol puts a good stretch on the gluteus maximus and that stretch number (2) is an effective stretch TFL stretch as well.  I suspect the benefits of stretching have to do with loosening this peripheral muscular tissue, not the IT band proper.

From Falvey et al.
Likewise, any soft tissue manipulation (be it massage, Active Release Technique, Graston, or just plain old foam rolling) should also be directed at the tissue around the IT band.  Knowing what we do about the irritation of the fat pad sandwiched between the lateral femoral epicondyle and the IT band (illustrated right), you should avoid any sort of "manipulation" of that area, since you'll only be making the problem worse.  While there's very little scientific evidence to support soft tissue manipulation, many veteran distance runners (including yours truly) will swear by their foam rollers as a great weapon against IT band syndrome.  Some even switch to a hard 3" PVC pipe if the foam roller feels too soft! While anecdotes aren't worth much scientifically speaking, it's awfully hard to argue against the experience of probably thousands of runners.  My best guess is that foam rolling, massage, and the like break down scar tissue and/or muscle adhesions in the quadriceps, glute, TFL, and hamstring muscles that the fascia lata surrounds and connects to.  But whether "scar tissue" and "muscle adhesions" even exist is a contentious issue, so I'll leave this as a guess! 

Finally, I should mention anti-inflammatories and local corticosteroids (delivered either with an injection or via iontophoresis).  While these can be good methods to control the swelling and reduce pain on the outside of the knee, you do have to address the root cause of the problem, which is likely to be hip abductor weakness and dysfunction.  Don't completely write off the lateral knee pain, though—remember my first injury maxim is that pain represents real, physical damage: so if the outside of your knee hurts, it's probably been damaged!  So avoid painful activities. You're only compressing and further damaging the sensitive tissue deep to the IT band.  Treat the symptoms and the cause.

Conclusion

We've seen how IT band is an often-misunderstood running injury.  The common conception is that the IT band is analagous to a thick cable which is irritated due to friction between the band and a bony protrusion of the femur just above the knee.  From this point of view, the most logical treatment options are addressing the inflammation and irritation on the outside of the knee.  But upon examining the scientific evidence, we've seen that it's anatomically impossible for the IT band to "slide" back and forth across the femur.  Instead, the IT band and the highly innervated tissue beneath it is biomechanically linked to the hip abductor muscles.  During running, the abductor muscles are supposed to control and limit hip adduction and knee internal rotation.  When the abductor muscles, particularly the gluteus medius and minimus, are weak or dysfunctional, the body cannot control these factors—this is why runners prone to iliotibial band syndrome exhibit weak abductor muscles and abnormally high hip adduction and knee internal rotation while running.  Although a randomized clinical trial showing the efficacy of hip abductor strengthening on treating and preventing iliotibial band syndrome has yet to be published, the preliminary and indirect evidence is very encouraging.

Until new research comes out, the best treatment plan for iliotibial band syndrome must include hip abductor strengthening.  The six-week Fredericson protocol, detailed above, includes two such exercises.  I've suggested three additional exercises to bolster the program with external rotator and isometric strength exercises.  Additionally, some clinical studies (most notably Fredericson's) as well as anecdotal evidence support using stretching, rolling/manipulation, and anti-inflammatory drugs.  In the case of stretching and rolling, these should be targeted at the tissue surrounding the IT band: for rolling and manipulation, the quadriceps, hamstrings, tensor fasciae latae (TFL), and glutes; for stretching, primarily the TFL and gluteus maximus.

One question I'm sure will come up is, "Do I have to take six weeks off from running for these strength exercises to work"? And as you might expect, I can't give a straight answer on that.  If you've caught your case of ITBS early, probably not.  You may even be able to get away with only a couple days off.  But, at least in my experience, it takes about a month of doing hip strength exercises every day to start seeing significant results.  This doesn't necessarily mean you have to take a month off from running, but it does mean that you should be patient if you aren't getting results quickly.  In any case, any running injury that doesn't resolve in a week or so usually warrants a trip to the doctor, who may be able to help you identify some of the particular causes of your specific case of iliotibial band syndrome.  Best of luck!

References 
(in order of appearance)

1.  Marti, B. et al. On the Epidemiology of Running Injuries. Am J Sports Med 1988; 16(3):285-94
2.  Taunton, J.E. et al. A retrospective case-control analysis of 2002 running injuries.  Br J Sports Med 2002;36:95–101.
3.  Fairclough, J. et al. The functional anatomy of the iliotibial band during flexion and extension of the knee: implications for understanding iliotibial band syndrome.  Journal of Anatomy 2006;208(3):309-316
4.  Fairclough, J. et al. Is iliotibial band syndrome really a friction syndrome? J Sci Med Sport. 2007 Apr;10(2):74-6.
5.  Fredericson, M. et al. Hip adductor weakness in distance runners with iliotibial band syndrome. Clin J Sport Med 2000;10:169–175.
6.  Ferber, R. et al. Competitive female runners with a history of iliotibial band syndrome demonstrate atypical hip and knee kinematics. J Orthop Sports Phys Ther 2010;40(2):52-58
7.  Noehren, B., Davis, I., and Hamill, J. Prospective study of the biomechanical factors associated with iliotibial band syndrome. Clinical Biomechanics 2007;22:951–956
8.  Murray, G.  Tensile strength and elasticity tests on human fascia lata. The Journal of Bone and Joint Surgery 1931; 13(2): 334.
9.  Falvey, E.C. et al. Iliotibial band syndrome: an examination of the evidence behind a number of treatment options. Scand J Med Sci Sports 2010;20:580–587
10.  Hamill, J. et al. A prospective study of iliotibial band strain in runners. Clinical Biomechanics;23(2008): 1018–1025



43 comments:

  1. This is an awesome article! I have (diagnosed) ITB syndrome and am currently undergoing rehab doing the same exercises you cite here. I have been reading for weeks online about various running injuries, yours is the first that I've seen that, like my Doctors, suggest that the issue is NOT in the knee but in the hip and gluteal areas.
    Unfortunately, my pain and diagnosis come 2 weeks before I go run the Disney Princess Half Marathon in Orlando. It was a dream for me to run this race, now I will be run/mostly walking it. I'm so disappointed but I am hopeful that my strengthening exercises and maybe a good rolling STICK will keep me healthy so I can run again very soon.
    I'm excited to find your blog and look forward to reading more from you!

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  2. Quite a study. It gets more and more interesting as i read it.

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  3. This is the most in-depth article I've stumbled across ever on ITBS. I suffered from ITBS 6 months back when I was running 18k for the first time. After that, I've tried various leg strength/ stretching/HIIT techniques. Even tried to change my posture with Chi running. None of them have been effective and I just cant increase my mileage per run.

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  4. I would like to point out one correction: it should be "stress-strain diagram" in
    " it's reasonable to expect that it ought to remain in the elastic portion of its stretch-strain diagram"

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  5. I am in the same boat as you Parn. I also cannot increase my mileage. My body just seems to tap out at 6-7 miles - then the IT band becomes inflammed.

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  6. Just wanted to say thank you for this article. After finishing my first marathon and then hearing from the doctor that my running career was over and little could be done aside from "pain-management," it's encouraging to read a more technical and proactive diagnosis. Going to try these stretches and exercises now. All the best.

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  7. Outstanding work. This along with your other injury reviews are now starred in my Google Reader, and I'm a fan. Keep it up!

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  8. I've been suffering from knee pain because of my IT band for over a year now. I struggled through training for my second full marathon last fall and now I'm working on my third one. I distinctly remember doing my 20 mile training run last fall and the pain in my knee started at mile 4. I pushed through the pain and stopped to refuel around mile 13. I've always been one who can push through the pain, but the pain was so terrible that I was literally crying and limping trying to get back into my run so I could finish the last 7 miles. Long story short, I am so grateful to have found this! I can't wait to start the strengthening program so that I don't have the same experience when I complete my long training runs this fall. Thank you for sharing!

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  9. Thank you for this awesome article. I'm a triathlete with knee pain that flared up in distance running and have suffered conflicting diganosis/treatment plans for 9 months. Got MRI results today that together with your article all add-up. It's caused from the hip imbalance! I was just given execises 4 & 1 from my physio too to address this but I might add in the others you've suggested, thanks. Good luck to all above in getting back to your running asap.

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  10. Here is conflicting information, I do not suffer from IT band pain, my suffering is from my hips due to weak hips due to prolong office sitting. I purchased a soft mattress and I am working on my hips performing ralax, flexibility, and strenght exercises in the same order. I have been running 3 miles per day 4 times per week, I rest 2 days. I am preparing for a 5k 18 min pace, my record is 14:48 at the age of 18, I am 49 now....Chuy

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  11. What a great article. After suffering from IT band syndrome for nearly eight months now, I went to the sports doctor last week and he also told me it's not because of knee problems, but because of hip strength problems. I've read a lot of articles about IT band syndrome, but yours is the first that explains every bit in a scientific and detailed manner.

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  12. This is a well written and researched article. It is the best one I came across as I struggled with my own IT problem. I highly recommend it.

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  13. Great article. One thing that's always puzzled me about this injury is that it comes back to rear it's ugly head after taking a couple of weeks off from running. In the past, it seemed to have just resolved itself the more I ran. If I took 4 weeks off for any other injury, ITBS would comeback. It's frustrating, since it ends up being a catch-22 situation.
    Perhaps I neglect hip strenghtening exercises during injury downtime, not sure. Anyway, will certainly give this a try. A lot of makes sense too, it seems I can almost recreate the pain by trying to "rotate" the knee inwards.

    One article published in Canada's The Globe and Mail, citing a University of Calgary study found the same results, although they encouraged runners to keep running if they could

    http://www.theglobeandmail.com/life/health-and-fitness/fitness/running/strengthening-beats-stretching-when-it-comes-to-this-common-running-injury/article4365074/

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  14. I'm the 45 yr old female triathlete that already commented above on 7th September but now nearly 3 months later I wanted to come back and once again thank you for this fabulous article. I've had an MRI, I've had cortisone treatments, I took 2 months rest from running, I've seen physios, I wear orthotics (3 years), and I follow a strength program in the gym, but this is the first time anyone has brought it all together and given me something that has really worked. The 4 Frederickson exercises plus your 3 extra have been my ticket to recovery. The key for me is to do these exercises every day I ride (3 times per week) - I spend about 40mins doing them because I also use the foam roller and do a few planks while I'm at it. I ride in morning, then sit at a computer. I swim in afternoons and run the days I don't ride to try give my hips a break. If I don't do your exercises as outlined, I get the return of terrible knee pain that completely stops me running so I have come to realise this is not a short-term fix but a life-long habit if I wish to continue cycling and running. I'm overjoyed that you've given me something specific that actually works to keep me pain-free. I have my 3rd half ironman in 6 weeks time and hopefully I might get through the run this time without a breakdown. Thanks so much, you're a legend.

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  15. Hi, I went to physiotherapist on 27th of September 2012 for a pain in my calf. At the same time, he made a full body check-up and diagnosed: 1- Hip flexors tightness 2- Gluteus medius / Hip abductor weakness.
    On 11th of November, during a 15K race, I start suffering from ITBS. I cannot run since then.
    Reading your article, I really think there is a direct link. Proving your theory.

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    1. Hi,
      Wanted to give some update about my ITBS.
      Since my last message on DEC 1st and after reading this article:
      - I've practiced hip abductor strengthening. Though less than requiered: 3 times a weeks only, 4 weeks (with 2 weeks break for xmas - new year)
      - I do 2 exercices (clamshell and lateral lift) x 30 rep. x 3 times x each side
      - I've started to run again since last weeks (totally 6 times, for 5k-5k-6k-6k-7.5k and 8k).
      - I stopped listening my ipod to listen to my body. I focus to my stride and try to adjust it

      And I DO NOT FEEL PAIN ANYMORE :) :)

      I hope I can gradually go back to my usual 15k/20k without pain. Keep you updated.

      John Davis, thank you so much!

      Delete
    2. That's great! Glad you are doing well, and best of luck going forward!

      Delete
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  17. Echoing what others have said, this is a great article. Finally, an attempt at applying scientific evidence to this condition. However, I wonder what causes the hip muscles to become imbalanced in the first place? I've run marathons for 8 years without incident. Then, when I cut my mileage back the dreaded pain on the side of the knee appears. Perplexing, indeed! Perhaps it's just the passage of time and effects of aging?

    Lastly, I agree with Milan's comment in October. It seems that the injury gets worse with more time off. I might try to keep running below the pain threshold - even it's just for 10 minutes - to stay loose. What is it about taking time off that makes it worse? Are things tightening up? Would this suggest that stretching plays a role in it?

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  18. The question of what causes hip muscle imbalance is a perplexing one, and there isn't much in the scientific literature on it. My own personal theory is that it has to do with how much we sit in our daily life, at work, at home, and in the car. But there's no proof for that! Aging could also play a role, as could a lack of "other" activities that use the lateral muscles of the hip. One study I saw linked time spent playing ball sports as an adolescent with a lower risk of stress fractures in runners later in life—perhaps because the varied jumping, running, and lateral cutting in soccer or basketball provided a different stimulus to the body. Maybe something similar is at hand with the hip muscles? I know a lot of elite coaches like Alberto Salazar and John Cook emphasize drills and strength exercises that target the lateral stability muscles because they believe that runners aren't using them enough in normal training.

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  19. Just wanted to say thanks for a great article.

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  20. This is a great article and really interesting reading. On question - could the ITBS be caused by walking? I do some running and don't really notice any significant pain on the outside of the knee but very recently (one during a round of golf and another towards the end of a 12-mile walk) I've had significant pain on the outside of the knee. It is now the day after the 12-mile walk and it is still extremely painful when walking. Initially I thought this may be down to a difference in leg length - but your article definitely suggests otherwise and I am intrigued as to whether weak hip abductors would put excessive strain on the IT Band while walking.

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  21. As a physician and triathlete, this is the best article I've ever seen on ITBS. Before I read this article, I realized that my gluteal pain must be related to my mid-quad/greater trochanter pain. And I have know that my hip adductors are weak. This articles pulls the pieces together beautifully. The scientific analysis in this article is really what makes it so different. Strong work! Anecdotally, I have found that mountain climbing decreases the pain - I think because it stretches and strengthens the adductors in a way that they don't get from my running and biking. I'm going to try to be a control for the Frederickson study by continuing to train (at a reduced level) at the same time that I start a dedicated adductor rehab program. WIll report back....

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  22. Hi John, I read your IT-band article on RunnersConnect. Thank you for this fantastically detailed article here. You cleared up my question about Fredericson's rehab protocol, because in his "Hip Abductor Weakness in Distance Runners with IT-Band Syndrome", he did not specify the frequency per day of the two strength exercises (only that the stretch exercises were 3 times per day)! So thank you for adding that here!

    I have two small questions; I know neither has a definite answer, but in case someone who is more versed in running injuries might have ever seen during their research:

    1) If a runner suffers IT-band syndrome for x years (versus x weeks), does the longer time period of experiencing the symptoms render it more difficult to recover via this rehab protocol?
    2) If a runner suffers pain not only in the stereotypical outside knee area, but also in the outside hip area, is there something s(he) should know about how this relates to optimal prevention and recovery?

    Thanks again!! :o)

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  23. This all makes sense... I realize that I was given very similar exercises by my sports MD a number of years ago when I first experienced ITB difficulties.
    Question: I believe ITB is again causing me problems;But in addition to the classical burning pain lateral, lower side of kneecap, I also have, alternatively aching or tingling in outer side of the lower leg and actual numbness in sole (arc area of my foot. Where is the nerve compression? the nerves in the fatty tissue near the lateral epicondyle?
    THAT is most uncomfortable. I have seen mention of burning pain like this in discussions of ITB syndrome but no real explanation.

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  24. Thank you so much for writing this review article! I have been poring over countless articles, forums, and websites but none of the explanations I read were as thorough as yours. I've been seriously training for 5ks for a year now, and just last month decided to try training for the SF half marathon. Over 4 weeks I increased mileage and intensity with few rest days, and now I have been suffering from on-and-off ITBS for the last 2 weeks since my usual long run 2 weekends ago.

    The next week I reduced mileage and intensity, then took a week off before the half marathon, which was yesterday. Like another person said, the twinge appeared at mile 4 of my race but it didn't really hit me until mile 9. The minute I stopped after the finish I was crying in pain and out of frustration, and I felt so desperate to find a solution. My knee is currently barking viciously at me and I've put it on ice. Walking is agonizing. But once the pain goes away I will get on the hip abductor strengthening plan ASAP..and continue running but with much less intensity and far fewer miles.

    Thanks so much again for writing such a thorough and insightful review. I hope to write back in a few weeks with good news. :)

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  25. This is the best article I've found on ITBS! What is your opinion on leg/knee braces that put pressure on the ITB? I will definitely be starting these exercises now, but I have a half marathon in 5 days. As of the past couple weeks I haven't been able to make it past 6 miles or so without excruciating pain. Thanks!

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  26. Great article! In fact one of the best currently available on the internet. I started to have the ITBS problems and aches two weeks ago (my normal weekly routine is 3x 12 - 15 km). I thought that I've overworked my left knee during a chilly day run and decided to give it a rest. Most of the pain subsided in one day, but any (however insignificant) attempt to resume my trainings resulted in searing pain. After two week of frustration I started to look deeper into the problem and found out that I have the ITBS and that it will not go away simply by resting. That's a MAJOR breakthrough for me! I'm starting the described protocol TODAY and hopefully I recover soon enough to resume my routine. Running is everything to me (ran 5 half marathons this year) and you just gave me hope for the future. Thank you!

    I will keep you posted about my achievments but in the meanwhile I'd like to ask if I should wear some orthopedical knee protection/support for better and faster recovery and prevention. Would it have any effect?

    Thanks again for this thorough article!

    Simon, Czech republic

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  27. Hi Simon,

    Glad you found the article useful! Some runners find that knee straps or braces can help with IT band syndrome, but there's no scientific research supporting it. From research that I've seen on other injuries like runner's knee, it appears that most of the benefit from knee supports, taping, and the like comes from the tactile feedback on your skin. Because of this, I've taken a liking to flexible kinesology tapes because they don't get in the way as much as a real knee strap or traditional athletic taping. But you can experiment around to see what works best for you. Good luck!

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  28. Great article John. You mainly focus on the development of IT band issues from running. I am primarily a biker and have had this issue for over a year. I was thinking it may have to do with my seat height. However, perhaps the abductor weakness might be contributing as well? However, I have muscular legs and hips so I am a bit perplexed. I have tried lowering my seat with no results.

    One other item. Are you aware of any surgery that corrects this? I have read about IT Band Release surgery but it appears to have mixed results. Either you get a really good result or a really bad result. There are some Ortho's that do it often and post their results on YouTube. It appears that the medical community has mixed feelings on attacking this problem surgically.

    Thanks for any thoughts.

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  29. Thanks for the comment! With regards to surgery, what little research there is says basically what you've said—results are mixed. The largest study I found just with a quick search right now looked at 45 surgical patients, with 49% having "excellent" results, 36% having "good" results, 13% having "fair" results, and 2% having "poor" results.

    With regards to causes in cycling, the most interesting biomechanical study I can find right now is this one: http://www.thekneejournal.com/article/S0968-0160%2802%2900090-X/abstract

    Which looked at the biomechanics of the knee in cycling. They recommend, as you've already done, lowering the seat height. Another review mentions strengthening the hip stabilizer muscles. In runners, at least, I have found that even very fit runners with strong "major" leg muscles like quads and hamstrings can have pathetically weak hip abductors and external rotators, so it's definitely worth a shot. Unfortunately there just isn't as much research yet on IT band syndrome in cyclists as there is in runners. Best of luck!

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  30. Thanks for the article!

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  31. Holy Cow!!! this has been an amazing article for me. I have hope after 18 months of it band related pain. Today I will start with the Fredericson Protocol and other three strengthening exercises. Maybe after the next 6 weeks I will get a full nights sleep. At 63, I love hiking and this should get me back to what I love to do. Thanks so much and to Claire for sharing this fabulous information.

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  32. Hi John,
    Here's the promised feedback on my ITBS and Fredericson protocol after 7 weeks of exercising.
    The results are somewhat encouraging, as the pain subsided and I can walk with no problems. However, attempts to return to my running routine still end in minor aggravation of the lateral knee. I can jog 9 km at 8 kph, but the knee hurts afterwards. It is bearable, but frustrating nevertheless.
    I'm still working on strenghtening my abductors and added pushups and situps to strenghten my back, abs and arms and generally to keep myself from getting fat :-).

    Visiting orthopedist yielded mixed results. Through x-ray he eliminated the possibility that my pain is caused by joint degradation or injury, in the range of two weeks he injected my knee with two very small doses of corticoids (sadly with no effect) in the area of the nerve cluster (fatty tisue) and sent me home to continue with my R'nR.

    Results are: I can walk, swim or sleep with no problems. Jogging still hurts a little (on a pain scale from 1 - 10 I'd say 2). Longer and faster runs are thus "no go" so far.

    I talked with the doctor about operation and he did not recommend it, as it could allegedly even worsen my current problem. He suggested that I continue with the exercises and offered non-invasive treatment with something that could be translated as a "shockwave therapy", that is often used to treat "tennis elbows" and such.

    To sum it up - It could be better and it could be worse :-) I'll keep you posted.

    P.S.: Muscular legs do not prevent you from getting ITBS. I'm inclined to believe that it even works the other way around O_o

    Simon, Czech republic

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  33. Hi Simon,

    Glad that you are making some improvements. Hopefully you continue to work your way back to fitness! I wrote an article on shockwave therapy a while back for another website, you can find it here if you want:

    http://runnersconnect.net/running-injury-prevention/is-shockwave-therapy-an-effective-treatment-option-for-chronic-running-injuries/

    I haven't seen anything on using it to treat IT band syndrome, though, so no telling if that will help or not.

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  34. Thanks John, another ballanced and very informative article (can't belive I nailed the translation of the procedure :-D). My own internet research about the procedure led me to similar conclusion. It is largely presented as a rocket-science-modern-miracle-cure, but mainly by people that are trying to sell it. I'll save it as a last measure, just a step before giving my money to a hoodoo practicioner or some other "faith-healer" :-)

    Simon

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  35. Great article. I've studied the area to some extent and have ITBS. Prior to reading this I had been doing hip extension and hip abductor & adductor strengthening, but this article definitely has shed more light on the subject for me, so thank you. I've learned the hard way that focusing on stretching doesn't work and for people who lead relatively sedentary life (i'm an engineer) that abdominal strength and pelvic position may be contributory. It seems the popliteus may have a role being an internal rotator of the tibia. Now I wear suspenders instead of belt and have stand up desk, both seem to help. Heating pad on the hips before bed has helped too.
    -Clayton

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  36. Hi there, just a few short questions!

    You specify doing both sides with stretching but what about the strength exercises? Both sides then too or just the injured side?

    Also, I can't really tell what is going on in image 4 of the Fredericson exercises. They both seem the same to me?

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  37. Hi Laura,

    To me at least, it makes sense to do the strength exercises on both sides. Runners who tend to get injured more often appear to have hip strength deficits on BOTH sides, not just the injured side. That being said, I have seen research on other injuries like Achilles tendonitis where the strength exercises are only done on one side. In this case, though, I think you should do both sides.

    In exercise 4, the exercise involves standing with one leg on a step and allowing your body weight to "tilt" down your hip, which is cantilevered out over the step. You use your hip muscles to raise your pelvis back up to level again, then repeat. I call this the "hip drop" exercise. Does this make sense? I can draw some pictures if it's still unclear.

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  38. Thanks, John! Your explanation makes sense and now I'll add that in with my exercises. I used to be a cross country runner and then I suffered ITBS badly over 8 years ago. Even walking was excruciating! I tried the couch-5k program recently after 8 years without running and enjoyed four months of running before ITBS struck again. But this time I'm determined to concur it!

    I'm on my first week of these exercises and I ordered some Zyflamend to hopefully alleviate some of the inflammation. Fingers crossed! Thank you so much for this article.

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  39. Thank you for this excellent article. I have been suffering for around 18 months with ITBS in my right knee and after trying everything including many unsuccessful physio sessions I was starting to give up. I used to be able to comfortably run half-marathon distance but I haven't managed more than about 4k in a very modest speed in that time.

    The most frustrating thing is that it is difficult to find the cause, but I feel a bit more positive after reading this as I am sure that my right glutes are a lot weaker than my left. I am going to start the recommended programme above (a lot of it is quite familiar to me from my physio sessions).

    I have a few observations from my own experience and I was wondering if I could get your take on them:
    1) One of my symptoms is a non-painful click in my right knee which I can't seem to get rid of even when I rest for weeks without running. This is considerably more prominent (though still not painful) after sitting down in a tight space or driving. I recently got off an 8-hour flight and it was clicking so loudly whilst walking afterwards that it was quite alarming. Is this likely connected to my ITBS and if so, do you think addressing the weakness in my right side will stop the problem?

    2) I am convinced that the muscle weaknesses have been caused by the fact that I work in an office job and that most days are therefore spent sitting down for 8-9 hours or more. Is there any particular guidance you can give on how to sit or why this would cause problems? I always cross my legs and find it incredibly hard to stop myself from doing so.

    3) The strengthening excercises definitely aggravate the pain in my knee. My physiotherapist recommended the clam excercise but after doing it my knee would always feel painful the next day, in the same way it would after going for a run. Is this just something I should expect, and put up with whilst I am strengthening my glutes?

    Thank you so much for the time you have spent on this article and any further help you can give.

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  40. I use a golf ball muscle massager for my IT band syndrome and it really does help and reduce the pain, If you want to try something new you should definitely look into it. www.zzathletics.com

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