IT Band Syndrome Part 3: Biomechanics
Our therapists in New York have read some studies that have shown increased hip adduction (leg closer to the midline) and knee internal rotation (lower leg turning in) during running in patients with IT band syndrome. Because the IT band attaches to the hip and knee, this pattern of motion lengthens the IT band, putting more tension and therefore stress on it.
- In the friction theory of IT band syndrome, this tensioned tissue would have more friction as the knee bends and straightens.
- In the impingement theory of IT band syndrome, this tension would cause greater compression of the IT band against the lateral bony protuberance of the knee.
This pattern of increased hip adduction and knee internal rotation motion may be due to:
- Hip abductor muscle weakness – when weak, the hip falls into more adduction
- Hip/knee or ankle joint stiffness – when a joint is stiff, it will move in the direction that is easier
- Possibly due to altered coordination
Another theory of altered biomechanics leading to IT band syndrome is excessive ankle eversion (sole of the foot faces out). Theoretically this makes sense but the research on this is conflicting. Because of the way the ankle joint and the lower leg are connected, excessive eversion of the ankle would lead to excessive internal rotation at the knee, putting a tension strain on the IT band as discussed above.
IT Band Syndrome part 4 will address the Physical Therapy assessment and treatment.
References:
Aderem J, Louw QA. Biomechanical risk factors associated with iliotibial band syndrome in runners: a systematic review. BMC Musculoskelet Disord. 2015;16:356. Published 2015 Nov 16. doi:10.1186/s12891-015-0808-7
Baker RL, Souza RB, Fredericson M. Iliotibial band syndrome: soft tissue and biomechanical factors in evaluation and treatment. PM R. 2011 Jun;3(6):550-61. doi: 10.1016/j.pmrj.2011.01.002. PMID: 21665168.
Ferber R, Noehren B, Hamill J, Davis IS. Competitive female runners with a history of iliotibial band syndrome demonstrate atypical hip and knee kinematics. J Orthop Sports Phys Ther. 2010 Feb;40(2):52-8. doi: 10.2519/jospt.2010.3028. PMID: 20118523.
Physical Therapy Guide to IT Band Syndrome , Choose PT website available at: https://www.choosept.com/symptomsconditionsdetail/physical-therapy-guide-to-iliotibial-band-syndrome-itbs