Tensor fasciae latae muscleTensor fasciae latae is a fusiform muscle located in the lateral aspect of the thigh. It belongs to the muscles of the gluteal region, along with the gluteus maximus, gluteus medius and gluteus minimus muscles.
Tensor fasciae latae is found superficial in the anterolateral aspect of the thigh, spanning from the anterior portion of the iliac crest to the superior portion of the tibia, onto which it inserts via the iliotibial tract. The main function of this muscle is to produce the extension and lateral rotation of the leg on the knee joint. Additionally, it contributes to the movements of the thigh, acting as a relatively weak abductor and medial rotator on the hip joint.
|Origin||Outer lip of anterior iliac crest, Anterior superior iliac spine (ASIS)|
Hip joint: Thigh internal rotation, (Weak abduction); Knee joint: Leg external rotation, (Weak leg flexion/ extension); Stabilises hip & knee joints
|Innervation||Superior gluteal nerve (L4-S1)|
|Blood supply||Ascending branch of lateral circumflex femoral artery|
This article will discuss the anatomy and the function of the tensor fasciae latae muscle.
Origin and insertion
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 tensor fasciae latae muscle is the most superficial muscle of the anterolateral aspect of the thigh. It is positioned lateral to the hip joint, immediately beneath the skin. In its superior aspect, tensor fasciae latae is found between the sartorius and gluteus medius muscle, where it overlays the gluteus minimus muscle. While descending down the thigh, the muscle is found between the two layers of fascia lata.
Due to its superficial position, this muscle is easily palpated. This is usually performed at the area located halfway between the anterior superior iliac spine and the greater trochanter of femur.
The innervation is supplied by the superior gluteal nerve (L4-S1) a branch of sacral plexus.
The tensor fasciae latae muscle is vascularized by the ascending branch of lateral circumflex femoral artery.
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 stabilize 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 leg.