The TFL is a hip muscle that is very well known to physiotherapists. Although, it is very small in size but plays a key role along with the gluteal muscles to assist in movement and stabilization of the hip and knee.
The Tensor fasciae latae muscle is a part of gluteal muscles which helps in abduction, flexion and internal rotation of the hip joint. It is a fusiform muscle that is present between two layers of fasciae latae. Actually tensor fasciae latae means “stretcher of the sideband”. Tensor is an agent noun which means “to stretch”. Fasciae is a term which means “of the band” and latae is an adjective which means “side”. Although it isn’t a thick muscle but can easily be palpated because it lies above all hip muscles, especially in athletes who strengthen their hip muscles for example weightlifters and hurdlers.
2) TFL Length:
The TFL muscle is approximately 15cm long.
3) Proximal Attachment:
TFL proximally attached to the anterior superior iliac spine (ASIS) and anterior part of the iliac crest.
4) Distal Attachment:
Distally it is attached to the fascia lata which is a deep fasciae wrapped around entire thigh musculature. The fibers of gluteus maximus, the tensor fasciae latae and the aponeurosis of the gluteus medius making a transverse reinforcement called iliotibial tract. This band of connective tissue goes on the lateral side over the knee joint and attached to the lateral patellar retinaculum and lateral condyle of the tibia.
5) Nerve Supply:
The TFL is innervated by the superior gluteal nerve which arises from the posterior divisions of anterior rami of L4-S1 spinal nerves of the sacral plexus. The superior gluteal nerve goes into the gluteal region through greater sciatic foramen above the piriformis muscle, courses laterally between gluteus minimus and medius till it reaches tensor fascia lata and innervates all of these muscles as well.
6) Blood Supply:
Tensor fasicae latae receives its blood supply from the deep branch of the superior gluteal artery which similar to superior gluteal nerve goes into the gluteal region via greater sciatic foramen above to the piriformis muscle. Here it divides into a superficial branch which supplies blood to the gluteal maximus and deep branch which supplies blood to the gluteus minimus, the gluteus medius and the tensor fasciae latae.
7) Venous Drainage:
The superior gluteal vein is a branch of internal iliac veins which serves as the venous drainage route.
- Basically the Tensor fasciae latae is a weak hip abductor but a prime mover in hip internal rotation.
- It works as a hip synergist in the abduction and flexion of the hip. To produce flexion, the TFL act along with the iliopsoas and rectus femoris. If due to any condition the iliopsoas becomes paralyzed, the tensor fasciae latae undergo muscular hypertrophy to compensate for the paralysis. TFL together with the gluteus medius and gluteus minimus works as an abductor/medial rotator.
- The TFL tenses the fasciae latae and iliotibial tract. Since the iliotibial tract is attached to the femur through the lateral intermuscular septum, the tensor produces movement of the leg to a small extent. In contrast, if the knee is completely extended, it helps to increase the extending force, stability and holds the femur on tibia when standing if a rhythmical movement from side to side occurs.
- Tensor fasciae latae also helps in the gait cycle by moving the ilium downward on the weight-bearing side, with resultant upward movement of the contralateral hip. As a result, it allows the leg of the non-weight bearing hip to swing through without hitting the ground during the swing phase of the walking.
- The basic functional movement of TFL is walking. The tensor fasciae latae is mainly used in water skiing, horse riding, and hurdling. Some difficulties arise when this muscle is tight or shorten are pelvic imbalances that cause pain in hips as well as lower back and lateral areas of knees.
8) Assessment of Power of TFL Muscle:
The power test for the TFL is done in side-lying with 450 of flexion for GRADE 5, 4 and 3. In contrast, it is done in a long sitting position for GRADE 2, 1 and 0.
The therapist is standing behind the patient with one hand on the lateral side of the thigh just above the knee, given downward pressure. The other hand is placed at the iliac crest to provide stability.
The patient is requested to perform abduction in opposition to resistance.
Grade 5 is given when the patient can abduct and maintain the position at the end range against full resistance.
Grade 4 is given when the patient can abduct and maintain the position at the end range against average resistance.
Grade 3 is given when the patient can abduct and maintain the position at end range against no resistance other than gravity.
Now, the therapist is standing on the side of the leg being assessed, by placing his one hand at the ankle to reduce friction between the plinth and the leg whereas the other hand is placed at the proximal anterolateral thigh. The patient is requested to move the leg towards the therapist.
Grade 2 is given when the patient can abduct to 300 and maintain position at end range.
For grade 1 & 0, the therapist will be standing in the same position as for grade 2 assessment but now the hand is placed on the lateral thigh just above the knee whereas the other hand is placed at the proximal anterolateral thigh to check TFL palpation easily. The patient is requested to move the leg towards the therapist.
Grade 1 & 0
Grade 1 is given when the therapist can feel the contraction of the muscle and grade 0 is given when no contraction is felt.
9) Clinical Significance:
As we know, tensor fasciae latae is used for so many movements, it can become clinically significant in cases of tightening, friction over bony prominences, or via its attachment to the iliotibial band. The TFL can become tight, especially in situations of prolonged shortening, for example, seated position for a long time. Tensor fasciae latae stretches (standing iliotibial stretch or wall iliotibial stretch) can lengthen this important muscle.
In a minority of cases, we noted that it is possible that a bent or sloped surface could predispose an individual to a TFL strain which can be painful. In this situation, treatment generally consists of heat packs, rest, and trigger point therapy and flexibility exercises for example iliotibial band stretching. Read More,