INTRODUCTION
ANATOMICAL CONSIDERATIONS
BIOMECHANICS OF THE RACE
ASSESSMENT
BIBLIOGRAPHY
INTRODUCTION
Iliotibial band syndrome (ITBS) is the main cause of lateral knee pain in runners and cyclists, accounting for 15% of overuse injuries. The diagnosis of ITBS is based on clinical examination: patients typically present with pain over the lateral femoral epicondyle and report sharp, burning pain when the physician presses on the lateral epicondyle during knee flexion and extension. The main diagnostic test for the assessment of ITBS is the Noble test, in which compression on the lateral epicondyle of the femur with a 30º knee flexion reproduces the pain suffered by the patient (1).
ANATOMICAL CONSIDERATIONS
The iliotibial band is a facial structure composed of dense connective tissue that aids postural stability and is capable of resisting large varus forces at the knee. At its proximal insertion the iliotibial band provides an insertion for the tensor fascia lata and gluteus maximus muscles. Distally the iliotibial band inserts into the Gerdy tubercle of the tibia and the lateral epicondyle of the femur. The iliotibial band has many other distal insertions such as the vastus lateralis, biceps femoris, and patellar retinaculum. The site of injury is normally associated with the insertion on the lateral epicondyle, but is interrelated with the forces created by the various insertions above and below the lateral epicondyle.
It is constantly debated whether friction syndrome occurs, or on the other hand, the pain appears due to the compression that the band itself makes on the highly innervated fat pad, which is located between the band and the femur and causes inflammation (2 ). Patients with ITBS have significantly thicker bands on MRI scans than controls without symptoms.
BIOMECHANICS OF THE CAREER.
Iliotibial band friction in runners occurs predominantly during the initial stance phase of gait (foot contact), very shortly after landing. This has been called the deceleration phase. Electromyographic studies of runners have shown that the gluteus maximus and tensor fasciae latae, the muscles that attach to the iliotibial band, are active only during the first 35% of the stance phase (and for an even shorter period during running and sprinting) During downhill running, the knee flexion angle when stepping is significantly reduced, which increases the tendency for friction because the knee spends more time in the impact zone. In contrast, ITBS is much less common in sprinters and multi-directional athletes because the knee flexion angle at strike increases with running speed. In general, the faster the running speed, the less time spent in the impact zone.
Once the initial inflammation has subsided, patients can be encouraged to freely train in activities that involve running faster than their usual training pace, including multidirectional sports such as tennis and basketball. These activities are unlikely to cause or aggravate ITBS, unless the iliotibial band is already inflamed, because the knee would not move through the zone of friction and inflammation. Slower jogging should only be attempted after you have successfully returned to faster activities, which is the opposite of treatment for most injuries. Downhill running is especially discouraged and runners are advised to train on flat ground to prevent the condition from recurring. Adjustments in running gait that place the knee in a more flexed position when stepping can prevent ITBS from occurring (3).
INTRINSIC CONTRIBUTING FACTORS
Several authors attribute iliotibial band tightness in runners to a greater maximum angle of hip adduction and a greater maximum angle of internal rotation of the knee compared to those of uninjured athletes. Furthermore, a greater eversion of the hindfoot combined with a dissymmetry in the length of the legs helps the lesion to increase mostly in the longer leg (4).
ASSESSMENT
The Ober test is commonly performed to evaluate the length of the liotibial i band. Gose and Schweizer [42] describe the Ober test as follows: (1) place the patient on their side, lying with the tested leg up; (2) with the knee flexed to 90° and the pelvis stabilized, place the hip in a flexion and abduction posture; (3) extend the hip to achieve adequate extension so that the iliotibial band is above or behind the greater trochanter; and (4) allowing the thigh to fall into adduction. Iliotibial band restriction is designated as follows: (a) minimal (adduction beyond the horizontal but not completely to the table), (b) moderate (adduction to the horizontal), and (c) maximum (the patient cannot adduce to the horizontal).
On the other hand, the Trendelenburg test can be a good indicator since it serves to assess the state of the gluteus medius muscle and the support point of the hip. With the patient uncovered and from behind, the pelvis and buttocks are observed, first supporting the healthy leg and then the diseased one. Under normal conditions the pelvis tilts upward. The test will be positive if the pelvis tilts downward, or on the other hand, a compensated trendelenburg does increase valgus tension and lateral ground reaction force to the knee, combined with an increase in hip adduction (5).
BIBLIOGRAPHY
1. Baker RL, Fredericson M. Iliotibial Band Syndrome in Runners. Phys Med Rehabil Clin NAm 2016;27(1):53-77. Disponible en: https://linkinghub.elsevier.com/retrieve/pii/S1047965115000650
2. Fairclough J, Hayashi K, Toumi H, Lyons K, Bydder G, Phillips N, et al. The functional anatomy of the iliotibial band during flexion and extension of the knee: implications for understanding iliotibial band syndrome. 2006;
3. Orchard JW, Fricker PA, Abud AT, Mason BR. Biomechanics of Iliotibial Band Friction Syndrome in Runners. Am J Sports Med 1996;24(3):375-9. Disponible en: http://journals.sagepub.com/doi/10.1177/036354659602400321
4. Orava S. Iliotibial tract friction syndrome in athletes–an uncommon exertion syndrome on the lateral side of the knee. Br J Sports Med 1978;12(2):69-73. Disponible en: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1859635/
5. Ferber R, Noehren B, Hamill J, Davis I. Competitive Female Runners With a History of Iliotibial Band Syndrome Demonstrate Atypical Hip and Knee Kinematics. J Orthop Sports Phys The 2010 ;40(2):52-8. Disponible en: http://www.jospt.org/doi/10.2519/jospt.2010.3028