The three gluteal muscles are extremely critical to our unique mode of bipedal locomotion. While the gluteus maximus is a very powerful hip extensor and is used as such during strenuous activities such as running, most of the time it limits hip flexion. Specifically, it keeps the trunk from collapsing into flexion due to momentum. The gluteus maximus has extensive distal attachment(s) including the gluteal tuberosity, and the iliotibial tract.

The iliotibial tract is a band of thick connective tissue that runs from the crest of the ilium to the proximal lateral side of the tibia. Both the tensor fascia lata and the gluteus maxiumus insert, at least in part, onto this band. Actually this tract is merely a modified lateral portion of the thick encircling deep fascia of the thigh- the fascia lata.

The gluteus medius and minimus are really the important muscles of this region because they allow us to lift and swing one leg forward to take the next step without falling to that side. Both of these muscles are hip abductors, but most of the time they limit hip adduction and thus prevent the pelvis from falling to the side of the lifted swinging leg.

These so-called lesser gluteals (medius and minimus) form the upper lateral quadrant of the buttocks and receive arterial blood and motor innervation from the superior gluteal artery and nerve. These nerves and vessels emerge from the pelvic cavity through the greater sciatic foramen just superior to the piriformis.

It is probably appropriate to include the tensor fascia lata with the gluteals. Of course this muscle is found on the anterior and lateral side of the upper thigh and not on the posterior region where the gluteals are located. It does, however, receive its motor innervation from the superior gluteal nerve like the lesser gluteals, and inserts on the iliotibial tract, as does the gluteus maximus.

There are many similarities between tensor fascia lata, iliotibial tract, and gluteus maximus in the hip, and the three heads of the deltoid in the shoulder.

Question: Can you name at least three similarities between the above mentioned structures?

Hint: Think about position and action.