Hip Muscles: Anatomy, Function, and Movement
Extension of the Hip
Muscles:
- Biceps Femoris
- Gluteus Maximus
- Semimembranosus
- Semitendinosus
Biceps Femoris
Full Description: This muscle consists of two heads (long and short portions).
Origin:
- The short head: In the lower third through the linea aspera.
- The long portion: The ischial tuberosity.
Insertion: Both heads meet in the back of the knee to end at the styloid process of the fibular head.
Function:
- The short portion: Flexor and external rotator of the knee.
- The long portion: Hip extensor, flexor, and external rotator of the knee.
Gluteus Maximus
Description: This is the thickest of the hip muscles and a great stabilizer of the pelvis, especially in bilateral contraction, preventing the trunk from moving forward. It prevents lumbar lordosis.
Origin: In the upper two-thirds of the external iliac fossa, in the back of the sacrum, in the coccyx, the sacroiliac ligaments, and all deep fibers originating in the fascia that separates the gluteus medius.
Insertion: The outer line of the linea aspera trifurcation. Many fibers end in the fascia lata.
Function:
- The upper fibers: Abductor.
- The lower fibers: Adductors.
- All fibers: Extensor and external rotator.
Semimembranosus
Description: A very strong muscle, protected against accidental injury. It is located in front of the semitendinosus.
Origin: From the ischial tuberosity. From there, it forms an elongated and flattened tendon, from which semipenniform muscle fibers depart.
Insertion: On the inside of the tibial plateau.
Function: Hip extensor, knee flexor, and internal rotator.
Semitendinosus
Description: It is palpable because it covers the gluteus maximus. Halfway, there is a tendon.
Origin: In the ischial tuberosity. From there, a thin muscle belly is formed in the middle third. It continues with a long tendon.
Insertion: With the gracilis and sartorius.
Function: Hip extensor, especially if the knee is locked in extension. Knee flexor, especially if the hip is flexed. Internal rotator of the knee.
Abduction of the Hip
Muscles:
- Gluteus Medius
- Gluteus Minimus
Gluteus Medius
Description: Located in front of the gluteus maximus.
Origin: In the middle of the external iliac fossa and iliac crest.
Function: With feet fixed, it stabilizes the pelvis. The contraction of the muscle is:
- Tonic: Maintaining the balance of the pelvis.
- Concentric: The opposite hip rises.
- Eccentric: Acts on the hip on the same side.
Gluteus Minimus
Description: Located in front of and within the gluteus medius. It is much thinner, but being enclosed increases its tension with little energetic repercussion.
Origin: In the front of the external iliac fossa.
Insertion: On the tip of the greater trochanter.
Function:
- Its most superficial fibers: Flexor and internal rotator. It is the most important internal rotator.
- Its most inferior fibers: Extensor and external rotator.
- When the abductor action is dominant, it balances the pelvis.
Adduction of the Hip
Muscles:
- Quadratus Femoris
- External Obturator
- Internal Obturator
Quadratus Femoris
Description: It is observed by removing the gluteus minimus and medius.
Origin: In the ischiopubic branch.
Insertion: On the back side of the greater trochanter.
Function: Adductor and external rotator of the hip.
External Obturator
Description: This is the deepest of all the muscles of the hip, square in front of the quadratus femoris.
Origin: In the outer rim of the obturator foramen.
Insertion: On the tip of the greater trochanter.
Function: External rotator. Booster of the joint capsule.
Internal Obturator
Description: This is a “V”-shaped muscle, fairly long, located on the quadratus femoris.
Origin: In the inner rim of the obturator foramen.
Insertion: On the tip of the greater trochanter.
Function: External rotator of the hip.
Rotation of the Hip
Muscles:
- Quadratus Femoris
- Gluteus Medius
- Gluteus Minimus
- External Obturator
- Internal Obturator