Muscles of the Pelvis and Thigh

Muscles of the Pelvis & Thigh.

Tensor Fasciae Latae

Action: Flex, medially rotate, and abduct the hip

Origin: Iliac crest, posterior to the ASIS

Insertion: Iliotibial tract

Iliotibial Tract

Superficial sheet of fascia (not technically a muscle) that covers the vastus lateralis – emerges from the Gluteal fascia.

Sartorius

Action: 

• Flex, laterally rotate, and abduct the hip
• Flex the knee
• Medially rotate the flexed knee

Origin: Anterior superior iliac spine

Insertion: Proximal, medial shaft of the tibia at pes anserinus tendon

Quadriceps group (4)

Action:  

• Extend the knee (tibiofemoral joint) -- all
• Flex the hip -- Rectus Femoris

Origin:

• Rectus Femoris: Anterior inferior iliac spine (AIIS)
• Vastus Medialis: Medial lip of linea aspera
• Vastus Lateralis: Lateral lip of linea aspera, gluteal tuberosity and greater trochanter
• Vastus Intermedius: Anterior and lateral shaft of the femur

Insertion: Tibial tuberosity (via the patella and patellar ligament)

Hamstring group (3)

Biceps Femoris

Action:

• Flex the knee
• Laterally rotate the flexed knee
• Long head: Extend the hip and assist to laterally rotate the hip
• Tilt the pelvis posteriorly

Origin:

• Long head: Ischial tuberosity
• Short head: Lateral lip of linea aspera

Insertion: Head of the fibula

Semitendinosus

Action:

• Flex the knee
• Medially rotate the flexed knee
• Extend the hip
• Assist to medially rotate the hip
• Tilt the pelvis posteriorly

Origin: Ischial tuberosity

Insertion: Proximal, medial shaft of the tibia at pes anserinus tendon

Semimembranosus

Action:

• Flex the knee
• Medially rotate the flexed knee
• Extend the hip
• Assist to medially rotate the hip
• Tilt the pelvis posteriorly

Origin: Ischial turberosity

Insertion: Posterior aspect of medial condyle of tibia

Gluteals

Gluteus Maximus

Action:

• Extend the hip
• Laterally rotate the hip
• Abduct the hip
• Adduct the hip (lower fibers)

Origin:

• coccyx
• edge of sacrum
• posterior iliac crest
• sacrotuberous and sacroiliac ligaments

Insertion: Iliotibial tract (upper fibers) and gluteal tuberosity (lower fibers)

Gluteus Medius

Action:  

• All fibers: Abduct the hip
• Anterior fibers: Flex and medially rotate the hip
• Posterior fibers: Extend and laterally rotate the hip

Origin:  

• Gluteal surface of ilium
• between posterior and anterior gluteal lines
• just below the iliac crest

Insertion: Lateral aspect of greater trochanter

Gluteus Minimus

Action: Abduct, medially rotate, and flex the hip

Origin: Gluteal surface of the ilium between the anterior and inferior gluteal lines

Insertion: Anterior aspect of greater trochanter

Adductor Group

Actions:

All: Adduct and medially rotate the hip

All except Gracilis: Assist to flex the hip

      Gracilis: Flex and medially rotate the flexed knee

   Posterior fibers of Adductor Magnus: Extend the hip

Adductor Magnus

Origin: Inferior ramus of the pubis, ramus of ischium and ischial tuberosity

Insertion: Medial lip of linea aspera and adductor tubercle

Adductor Longus

Origin: Pubic tubercle

Insertion: Medial lip of linea aspera

Adductor Brevis

Origin: Inferior ramus of pubis

Insertion: Pectineal line and medial lip of linea aspera

Pectineus

Origin: Superior ramus of pubis

Insertion: Pectineal line of femur

Gracilis

Origin: Inferior ramus of pubis

Insertion: Proximal, medial shaft of tibia at pes anserinus tendon

Lateral Rotators of the Hip

Action:  

• All laterally rotate the hip at the coxal joint
• Piriformis abducts the hip when the hip is flexed.

Piriformis

 Origin: Anterior surface of sacrum

Insertion: Superior aspect of greater trochanter

Quadratus Femoris

Origin: Lateral border of ischial tuberosity

Insertion: Intertrochanteric crest, between the greater and lesser trochanters

Obturator Internus

Origin: Obturator membrane and inferior surface of obturator foramen

Insertion: Medial surface of greater trochanter

Obturator Externus

Origin: Rami of pubis and ischium, obturator membrane

Insertion: Trochanteric fossa of femur

Gemellus Superior

Origin: Ischial spine

Insertion: Medial surface of greater trochanter

Gemellus Inferior

Origin: Ischial tuberosity

Insertion: Medial surface of greater trochanter

Iliopsoas group

Psoas minor

Action: Posterior rotation of pelvis.

Origin: Anterolateral surface of T12 and L1 vertebrae.

Insertion: Superior ramus of pubis. Action: Posterior rotation of pelvis.

Psoas Major

Action:

• With the origin fixed: flex the hip, may laterally rotate the hip
• With the insertion fixed: flex the trunk toward the thigh, tilt pelvis anteriorly
• Unilaterally: Assist to laterally flex the lumbar spine

Origin: Bodies and transverse processes of lumbar vertebrae

Insertion: Lesser trochanter

Iliacus

Action:

• With the origin fixes: flex the hip, may laterally rotate the hip
• With the insertion fixed: flex the trunk toward the thigh, tilt pelvis anteriorly

Origin: Iliac fossa

Insertion: Lesser trochanter

That's all of them!