IT band tends to be considered as more of a tendon than a ligament because it connects TFL and hip muscles to the bone, which is a main feature of tendons. Also, as explained in the previous posting, the cause of IT band problems are considered to be excessive 'friction' or 'tension', so it can be seen as similar to the mechanism of developing tendinitis/tendinopathy as described in the references below.

This paper was published in 2016 and presented three models of the causes of tendinitis/tendinopathy.

- 1st model: Understimulation

Recent studies have shown that collagen fibers cause problems as they twist or stretch rather than tear unless they are seriously injured. The potential cause of this distortion or stretch of collagen fibers is understimulation (lack of exercise). Understimulation is the opposite of overstimulation/overloading so this can be interpreted like this. When you don't exercise, your tendons get weaker due to understimulation. In this state, a slight overloading on weak tendons can cause problems.

- 2nd model: Inflammation

It is found that when an injury occurs, cytokine (inflammatory response) increases 1,000-10000 times. However, this level has increased 1.5 times only in tendinitis, which means that tendinitis is unlikely to occur due to inflammation. Therefore, these days, the expression 'tendonitis' which means the tendon is inflamed is being replaced with the expression 'tendinopathy' which means the tendon has a pathology.

- 3rd model: Compressive loading

It is strongly suggested that the cells that make up tendons react to external shocks or compression by adjacent bones. The author believes that this third model explains the phenomenon most logically and it can occur in combination with the two aforementioned reasons. Another paper published in 2012 further states that compression can cause a more harmful effect when it occurs with tension.

In summary, when muscles become tight due to body shape imbalance, muscle dysfunction, and overload, the tendons connected to them get pulled (tension increases). In addition, if compression occurs at the point where the tendon and nearest bone meet, tendon problems are likely to occur. IT band syndrome also occurs in a similar pattern as explained in the above posting.

References

Cook, J. L., & Purdam, C. R. (2009). Is tendon pathology a continuum? A pathology model to explain the clinical presentation of load-induced tendinopathy. British journal of sports medicine, 43(6), 409-416.

Cook, J. L & Purdam, C. (2012). Is compressive load a factor in the development of tendinopathy? British Journal of Sports Medicine, 46(3), 163-168.

Cook, J. L., Rio, E., Purdam, C. R., & Docking, S. I. (2016). Revisiting the continuum model of tendon pathology: what is its merit in clinical practice and research?. British journal of sports medicine, 50(19), 1187-1191.

Zügel, M., Maganaris, C. N., Wilke, J., Jurkat-Rott, K., Klingler, W., Wearing, S. C., ... & Bloch, W. (2018). Fascial tissue research in sports medicine: from molecules to tissue adaptation, injury and diagnostics: consensus statement. Br J Sports Med, 52(23), 1497-1497.