Iliotibial band: What is the function and how to manage discomfort?

ITB syndrome –  Is it friction or compression that causes the issue?

Iliotibial Band Syndrome (ITBS) stands out as a prevalent overuse injury with profound implications for athletes engaged in activities like running and cycling. Characterised by lateral knee pain, particularly exacerbated during actions like single-leg stance, ITBS holds the position of being the most common relative overuse injury at the lateral knee, contributing to approximately 12% of all running-related injuries and making substantial impacts in cycling and military-related contexts.

Historically perceived as a friction injury, the conventional wisdom held that cyclic loading during activities like running and cycling led the iliotibial band to rub the lateral epicondyle, causing irritation to the innervated fatty tissue beneath.

However, recent insights by Fairclough et al. have shaken this foundational belief, suggesting that the perceived friction might be an illusion. Their questioning of the friction mechanism proposes an alternative view, emphasising the sequential load shifting of ITB fibers from anterior to posterior during tensioning.

Adding a new dimension to our understanding, a novel theory supported by magnetic resonance imaging (MRI) suggests that when the knee flexes beyond 30°, the ITB compresses medially against the lateral femoral epicondyle. This compression mechanism introduces a paradigm shift, proposing that ITBS should be classified as a compression syndrome rather than a friction injury.

As we delve deeper into the pathomechanics of ITBS, this evolving narrative contributes not only to a refined understanding of the condition but also paves the way for more targeted and effective approaches to its prevention and treatment.

Running Kinematics in Iliotibial Band Syndrome

Running kinematics in individuals developing ITBS reveal movements that distinguish them from healthy controls. Studies by Noehren et al. and Friede et al. observe increased hip adduction and knee internal rotation in those prone to developing ITBS during running.

Contrastingly, runners with prior ITBS history exhibit reduced hip adduction compared to their healthy counterparts. This paradoxical finding suggests that individuals who have experienced ITBS may alter their running patterns as a protective adaptation.

Furthermore, investigations show a gradual decline in peak hip adduction angle during prolonged runs in individuals with ITBS. This decline may indicate a strategic shift in running kinematics, possibly adopted to alleviate pain or mitigate strain on the ITB as the run progresses.

In essence, these collective findings suggest that runners, whether prone to or with a history of ITBS, may adopt altered movement patterns in response to pain or injury, showcasing the remarkable adaptability of the human body.

Diagnosis and Differential Considerations

Diagnosing ITBS involves a keen understanding of the distinctive symptoms and potential differential diagnoses. Runners grappling with ITBS commonly report lateral knee pain, specifically situated around 2–3 cm proximal to the lateral tibiofemoral joint line, particularly emphasising the lateral femoral condyle.

The onset of ITBS pain typically follows an insidious pattern, often linked to recent surges in running loads. This surge might manifest as an increase in running distance or a higher volume of downhill running, signalling a critical clue for diagnosis.

Individuals with particularly irritable ITBS may experience pain during stair descent in the stance limb, especially during hip extension and knee flexion. This discomfort aligns with the eccentric contraction of the TFL muscle, contributing to lower limb control.

For an accurate diagnosis, clinicians must rule out alternative sources of lateral knee pain. These may include:

1. Patellofemoral pain
2. Lateral meniscal lesions
3. Lateral synovial plica syndrome
4. Distal femoral bone stress injuries.

Specific clinical assessments and screenings play a crucial role in this process.

Additionally, considering conditions like gluteal tendinopathy and lumbar radiculopathy is important, as these may refer pain to the lateral thigh and knee.

Noble Compression Test: A Diagnostic Tool for ITBS

When it comes to diagnosing suspected Iliotibial Band Syndrome, the Noble compression test takes the lead as a primary diagnostic evaluation. This straightforward yet informative test involves the application of manual pressure to the lateral knee, specifically targeting a point 1–2 cm proximal to the lateral femoral condyle. The knee is then passively extended through a range of motion from 60° to full extension.

A positive result in the Noble compression test is identified when the maneuver elicits the reproduction of lateral knee pain, particularly when the knee is positioned at approximately 30° of knee flexion. This specific angle is crucial for the sensitivity of the test, capturing potential discomfort associated with ITBS.

However, it’s essential to approach test interpretation with caution, as the Noble compression test currently lacks established positive and negative likelihood ratios.

Ober’s Test and Hip Weakness in ITBS

The Ober test has become a go-to tool for clinicians assessing ITB “tightness,” with both classic and modified versions widely employed. Despite the common assumption that an injured ITB is inherently tighter than a healthy one, neither iteration of the Ober test appears to effectively measure this perceived “tightness.”

A positive result in the Ober test often indicates restrictions in the hip capsule and the musculature of the gluteus medius and minimus. However, it’s crucial to note that neither version of the Ober’s test is particularly helpful in diagnosing ITBS or assessing ITB “tightness.”

In individuals with ITBS, a prevalent observation is hip abductor weakness. Interestingly, this weakness is considered a consequence of ITBS rather than a contributing factor. The relationship between hip abduction strength and ITBS remains unclear due to the absence of prospective studies. It is hypothesised that pain arising from distal compression within the highly innervated tissues of the ITB may hinder proximal hip musculature.

Adaptive engagement of the TFL and gluteus maximus in strategies to diminish tension in the ITB may further complicate the relationship. Thus, the presence of hip weakness appears to be concurrent with ITBS rather than being a causative factor in the onset of this injury.

Treatment for ITBS: Progressive Overload and Graded Exposure

The treatment of Iliotibial Band Syndrome is a topic often explored in scientific literature, although the quality of available evidence is frequently constrained to narrative reviews or case series, typically of lower quality.

Despite these limitations, a consistent and widely recommended approach for individuals seeking recovery from ITBS involves the integration of progressive overload and graded exposure to progressively challenging activities. This  strategy acknowledges the need for a gradual increase in intensity, allowing the affected tissues, particularly the iliotibial band, to adapt and strengthen over time.

Progressive overload entails a systematic and incremental increase in the demand placed on the body during physical activity. This may involve modifying running surfaces, distances, or incorporating specific strength and conditioning exercises targeting the hip and knee musculature.

Graded exposure emphasises a gradual re-introduction of activities that may have contributed to or exacerbated ITBS symptoms. This approach allows individuals to acclimate to the demands of running or other activities while minimising the risk of symptom recurrence.

While the literature may lack high-quality evidence, the consensus on the importance of progressive overload and graded exposure suggests a practical and pragmatic foundation for managing ITBS. Individualised treatment plans, incorporating these principles, can empower individuals to regain function and resume their desired level of physical activity with reduced risk of recurrence.

Foam Rolling and Stretching for ITB

Foam rolling of the ITB has become a popular recommendation for runners grappling with perceived ITB “tightness” or ITBS. However, despite its widespread use, the effects of foam rolling on flexibility appear to be short-lived or minimal, with any pain relief achieved being temporary and lasting only a few minutes.

Stretching the ITB, while often suggested, presents challenges, especially in the context of assessing ITB “tightness” as exemplified by the Ober test. This test, commonly used in clinical settings, may not effectively measure true ITB “tightness.”

A recent study by Friede et al. delved into ITB stiffness using shear-wave elastography, investigating both healthy participants and those experiencing ITBS symptoms after a 6-week training period. Surprisingly, the study found no discernible differences in ITB stiffness between healthy individuals and those with ITBS.

These findings show the limitations of common strategies like foam rolling and stretching when addressing ITB-related concerns. While these techniques may offer temporary relief, a more comprehensive approach that considers individualised factors contributing to ITBS and incorporates progressive and graded interventions may be a lot more beneficial.

Hip Strength and ITBS

Hip strengthening has emerged as a common recommendation for individuals grappling with ITBS. While a hip-strengthening program has demonstrated concurrent resolution of hip weakness and pain in runners with ITBS, caution is urged in attributing causation to hip weakness, as it typically follows the onset of ITBS.

Interestingly, hip strength does not appear to correlate with hip adduction during running, challenging a prevalent belief among clinicians. Contrary to expectations, engaging in hip strengthening exercises does not necessarily result in a reduction in hip adduction during running.

An alternative explanation for the pain relief experienced by individuals with ITBS following hip strengthening lies in the potential of targeted loading exercises, like intensive hip strengthening, to alter central pain processing and diminish local hyperalgesia. This suggests that the benefits of hip strengthening may extend beyond solely addressing biomechanical factors, influencing broader pain perception and tolerance.

Running Biomechanics for ITB Health

Addressing running biomechanics holds promise in mitigating suspected increases in ITB strain and subsequent compressive loads on the lateral knee. A study by Meardon et al. utilised a subject-specific musculoskeletal model during running, uncovering that adopting a wider step width effectively reduces ITB strain.

Implementing interventions to optimise running biomechanics can be straightforward and practical. Providing feedback on step width, a key factor in influencing ITB strain, can be easily achieved using a full-length mirror during treadmill running, offering real-time visual cues for runners.

Another impactful intervention involves increasing running cadence, also known as stride frequency. This adjustment has demonstrated the ability to reduce both ITB strain and strain rate, as evidenced by a comparable musculoskeletal model. Encouraging an uptick in running cadence aligns with practicality, as it can be seamlessly implemented during routine, in-field runs through the use of commercially available wearable devices, providing real-time feedback to runners.

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Source:

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• Fairclough, J., Hayashi, K., Toumi, H., Lyons, K., Bydder, G., Phillips, N., Best, T.M. and Benjamin, M., 2006. The functional anatomy of the iliotibial band during flexion and extension of the knee: implications for understanding iliotibial band syndrome. Journal of anatomy, 208(3), pp.309-316.
• Friede, M.C., Klauser, A., Fink, C. and Csapo, R., 2020. Stiffness of the iliotibial band and associated muscles in runner’s knee: Assessing the effects of physiotherapy through ultrasound shear wave elastography. Physical Therapy in Sport, 45, pp.126-134.
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• Neumann, D.A., 2010. Kinesiology of the hip: a focus on muscular actions. Journal of Orthopaedic & Sports Physical Therapy, 40(2), pp.82-94.