Anatomy of the Iliotibial Band
The iliotibial band is merely a lateral expansion of the fascia lata and made up of three layers: superficial, middle and deep.
Superficial and middle layer: encloses the tensor fascia lata anchoring it to the iliac crest. These layers unite at the distal end of the tensor fascia lata to form a tendon for the muscle. These two united layers receives fibers from the gluteus maximus and runs down the lateral thigh. As it courses down the lateral thigh Fairclough et al (2006) found the Iliotibial band continuous with the strong lateral intermuscular septum, which was firmly anchored to the linea aspera of the femur. Evans (1979) found fibers from the lateral intermuscular septum form the horizontal fibers of the iliotibial band.
Distally, after coursing through the Biceps Femoris and Vastus Lateralis, Fairclough et al (2006) found the iliotibial band attached to the region of, or directly to, the lateral epicondyle of the femur by strong fibrous ‘tendonous’ strands and then more ‘ligamentous’ strands between the lateral epicondyle of the femur and Gerdy's tubercle on the tibia. Conversely to popular belief no bursa was found between the tendonous fibrous bands of the Iliotibial band and femur just adipose tissue. Evans (1979) found additional attachments to the patella retinaculum and lateral meniscus.
Wilke et al (2016) found more distally the Iliotibial band connected strongly to the crural fascia which in itself was hardly seperable from the peroneal longus fascia.
Deep layer: The deep layer of the iliotibial band merges where the superficial and middle layers fuse distal to the tensor fascia lata (Putzer et al 2017). From here it runs deep attaching to the vastus lateralis and rectus femoris fascia. Coursing deeper still it follows the iliofemoral ligament to attach to the supraacetabular fossa between the tendon of the reflected head of the rectus femoris and the hip joint capsule. It resists hip extension.
Additional muscular attachments to the Iliotibial band include:
· Vastus Lateralis (Becker et al 2010).
· Biceps Femoris.
· Tensor Fascia Lata.
· Gluteus Maximus.
Anatomy of the Tensor Fascia Lata
The Tensor Fascia Lata arises from the anterior part of the outer lip of the iliac crest; from the outer surface of the anterior superior iliac spine, and part of the outer border of the notch below it, between the gluteus medius and sartorius; and from the deep surface of the fascia lata.
It is inserted between the two layers of the iliotibial band at about the junction of the middle and upper third of the thigh.
Actions of the Tensor fascia Lata
Traditionally the Tensor Fascia Lata along with the more vertical anterior and middle fibers of the Gluteus Medius are involved in hip abduction holding the pelvis horizontal during the stance phase of the gait:
Heel strike: anterior fibers of the Gluteus Medius initiates initial abduction during the heel strike keeping the pelvis horizontal.
Mid-stance: Tensor Fascia Lata keeps the pelvis horizontal. Anterior rotation of the pelvis is achieved from the anterior fibers of the Gluteus Medius.
The hip joint is stabilised with the posterior fibers of the Gluteus Medius from heel strike to mid-stance and from the Gluteus Minimus from mid-stance to back stride (Gottschalk et al 1989).
The other actions of the Tensor Fascia Lata include very weak internal rotation and knee extension (Umehara et al 2015).
Stretching of the Iliotibial band
Fredericson et al (2002) found a hip adduction stretch with the subjects arms reaching over head (i.e full shoulder abduction and extension) increased the stretch on the Iliotibial Band. Wilhelm et al (2017) found that a similar stretch to this (without using the added leverage of the shoulder position) didn’t uniformly increase the stretch throughout the iliotibial band but did so most prominently in the proximal portion.
Evans (1979) found the deep layer of the iliotibial band resisted hip extension.
Fairclough et al (2006) noted the tension of the distal part of the Iliotibial Band altered at different degrees of knee flexion:
Initial knee flexion: during initial knee flexion bands of the Iliotibial Band that attach to the patella come under tension as the patella rotates laterally.
Further knee flexion: as the knee is further flexed tension shifts from the anterior to posterior bundles of the Iliotibial Band possibly due to the attachments of the Biceps Femoris.
As the tibia moves posteriorly the ligamentous part of the iliotibial band that attaches from the lateral femoral epicondyle to Gerdy’s tubercle of the tibia comes under tension. Fairclough et al (2006) gave the impression this posterior movement was on progressive knee flexion not a posterior shunt of the tibia from knee extension.
Stretching of the Tensor Fascia Lata
Traditionally the Tensor Fascia Lata has been stretched using hip adduction/extension/external rotation.
Umehara et al (2015) found that hip adduction/extension with added knee flexion at >90 degs stretched the Tensor Facsia Lata more than adding hip external rotation. This was because the Tensor Fascia Lata very minimally if not at all was used for hip internal rotation.
This may explain why using knee flexion reduced the range of motion in hip adduction when performing Ober’s test (Gajdosik 2003)
Quantitative analysis of the relative effectiveness of 3 iliotibial band stretches (2002). Fredericson M, White JJ, Macmahon JM, Andriacchi TP.
The functional anatomy of the iliotibial band during flexion and extension of the knee: implications for understanding iliotibial band syndrome (2006). John Fairclough, Koji Hayashi, Hechmi Toumi, Kathleen Lyons, Graeme Bydder, Nicola Phillips,Thomas M Best, and Mike Benjamin.
DEFORMATION RESPONSE OF THE ILIOTIBIAL BAND-TENSOR FASCIA LATA COMPLEX TO CLINICAL-GRADE LONGITUDINAL TENSION LOADING IN-VITRO (2017). Mark Wilhelm, Omer Matthijs, Kevin Browne, Gesine Seeber, Anja Matthijs, Phillip S. Sizer, Jean-Michel Brismée, C. Roger James, Kerry K. Gilbert.
The functional anatomy of tensor fasciae latae and gluteus medius and minimus (1989). FRANK GOTTSCHALK, SOHRAB KOUROSH AND BARNEY LEVEAU.
Effect of hip and knee position on tensor fasciae latae elongation during stretching: An ultrasonic shear wave elastography study (2015). Umehara J, Ikezoe T, Nishishita S, Nakamura M, Umegaki H, Kobayashi T, Fujita K, Ichihashi N
The vastus lateralis muscle: an anatomical investigation (2010). Becker I, Baxter GD, Woodley SJ.
Influence of knee positions and gender on the Ober test for length of the iliotibial band (2003). Gajdosik RL, Sandler MM, Marr HL.
Anatomical study of the morphological continuity between iliotibial tract and the fibularis longus fascia (2016). Wilke J, Engeroff T, Nürnberger F, Vogt L, Banzer W.