Tensor fasciae latae muscle
The tensor fasciae latae muscle belongs to the group of gluteal muscles. Even though the tensor fasciae latae isn't considered a thick muscle, it can easily be palpated since it lies above all hip muscles, particularly in athletes who engage and strengthen their hip muscles, such as hurdlers and weightlifters.
The muscle is both functionally and structurally related with the gluteus maximus. It is continuous with the iliotibial tract, which attaches to the tibia. The tensor fasciae latae muscle contributes to maintaining the balance of the pelvis while the body is mobile.
|Origin||Outer lip of anterior iliac crest, Anterior superior iliac spine (ASIS)|
|Innervation||Superior gluteal nerve (L4-S1)|
Hip joint: Thigh internal rotation, (Weak abduction); Knee joint: Leg external rotation, (Weak leg flexion/ extension); Stabilises hip & knee joints
This article will discuss the anatomy and the function of the tensor fasciae latae muscle.
Origins & Insertions
The muscle originates from the outer lip of the anterior iliac crest and the anterior superior iliac spine. Distally its fibers attach to the fascia lata - a deep fascia surrounding the entire thigh musculature. The tensor fasciae latae, the fibers of the gluteus maximus and the aponeurosis of the gluteus medius form a horizontal reinforcement known as the iliotibial tract. This band of connective tissue runs laterally over the knee joint and inserts at the lateral condyle of tibia and lateral patellar retinaculum.
The innervation is supplied by the superior gluteal nerve (L4-S1).
The main task of the tensor fasciae latae is to sustain tension of the iliotibial tract. As the femoral shaft meets the pelvis, an angled pressure from above imposes a high bending strain to the femur. Both the hip abductors and the tensor fasciae latae counteract the pressure on the opposite side and help stabilize the bone (tension banding effect). Furthermore, the activation of the muscle leads to an abduction, flexion and internal rotation of the hip joint.
Contraction of the tensor fasciae latae muscle also causes external rotation of the leg at the knee joint. Furthermore, it aslo weakly flexes the leg, when there an existing degree of flexion greater than 20 degrees, and weakly extends the leg, when the angle of flexion is less than 20 degrees.
Finally, the TFL also works to stabilise both the hip and knee joints.
A bursa is located between the iliotibial tract and the lateral condyle of tibia protecting the band from the underlying femur. However, overstraining and increased activity of the tendon can result in an inflammation of the bursa (iliotibial band syndrome).
Endurance athletes, such as joggers and bicyclists, with leg deformities (e.g. genu varum, flat foot) are particularly prone to this condition. Clinically, patients present a short, overly tense iliotibial tract, swelling above the lateral condyle of tibia and pain which increases during movements of the lower leg.