Lesson 19

A: Extends thigh at hip as in stair climbing (rising to next step) or running and walking (backswing of limb); abducts thigh; elevates trunk after
stooping; prevents trunk from pitching forward during walking and running; helps stabilize femur on tibia
O: Posterior gluteal line of ilium, on posterolateral surface from iliac crest
to posterior superior spine; coccyx; dorsal surface of lower sacrum;
aponeurosis of erector spinae
I: Gluteal tuberosity of femur; lateral condyle of tibia via iliotibial band

The fascia lata is
a fibrous sheath that encircles the thigh like a subcutaneous stocking and tightly binds its muscles. On the lateral surface, it combines with the tendons of the gluteus
maximus and tensor fasciae latae to form the iliotibial band, which extends from the iliac crest to the lateral condyle of the tibia

A: Abduct and medially rotate thigh; during walking, shift weight of trunk toward limb with foot on the ground as other foot is lifted
O: Most of lateral surface of ilium between crest and acetabulum
I: Greater trochanter of femur

a:Abduct and medially rotate thigh; during walking, shift weight of trunk toward limb with foot on the ground as other foot is lifted
O: Most of lateral surface of ilium between crest and acetabulum
I: Greater trochanter of femur

a fibrous sheath that encircles the thigh like a subcutaneous stocking and tightly binds its muscles. On the lateral surface, it combines with the tendons of the gluteus
maximus and tensor fasciae latae to form the iliotibial band, which extends from the iliac crest to the lateral condyle of the tibia

A: Aids in knee and hip flexion, as in sitting or climbing; abducts and laterally rotates thigh
O: On and near anterior superior spine of ilium
I: Medial surface of proximal end of tibia

; Flexes and medially rotates tibia at knee
O: Body and inferior ramus of pubis; ramus of ischium
I: Medial surface of tibia just below condyle

All heads insert on tibia through a common tendon and extend the knee, in addition to the actions of
individual heads below:
rectus femoris
vastus lateralis
vastuc medialis
vastus intermedius


-prime mover of knee extension and the most powerful muscle in the body
it has four heads.

part of quadriceps femoris m.
A: Extends knee; flexes thigh at hip; flexes trunk on hip if thigh is fixed
O: Ilium at anterior inferior spine and superior margin of
acetabulum; capsule of hip joint
I: Patella, tibial tuberosity, lateral and medial condyles
of tibia

part of quadriceps femoris m.
A: Extends knee; retains patella in groove on femur during knee movements
O: Femur at greater trochanter and intertrochanteric line, gluteal
tuberosity, and linea aspera
I: Patella, tibial tuberosity, lateral and medial condyles
of tibia (same as rectus femoris)

part of quadriceps femoris m.
A: Extends knee; retains patella in groove on femur during knee movements
O: Femur at intertrochanteric line, spiral line, linea aspera, and
medial supracondylar line
I: Patella, tibial tuberosity, lateral and medial condyles
of tibia (same as rectus femoris)

part of quadriceps femoris m.
A: extends knee
O: anterior and lateral surfaces of femoral shaft
I: patella, tibial tuberosity, lateral and medial condyles of tibia (same as rectus femoris)

all four heads of the quadriceps femoris m. converge on a single quadriceps (patellar)
tendon, which extends to the patella, then continues as the patellar
ligament and inserts on the tibial tuberosity. (Remember that a tendon
usually extends from muscle to bone, and a ligament from bone to
bone.)

connects patella and tibia

The posterior compartment
contains three muscles colloquially known as the hamstring muscles; from lateral to
medial, they are the biceps femoris
(long and short head), semitendinosus, and semimembranosus

A: flexes knee
O: long head - ischial tuberosity
short head - linea aspera and lateral supracondyle line of femur
I: head of fibula

A: flexes knee
O: ischial tuberosity
I: medial surface of upper tibia

A: flexes knee
O: ischial tuberosity
I: medial condyle and nearby margin of tibia, intercondylar line and lateral condyle of femur, ligament of popliteal region

a common injury in athletes
the biceps femoris m, semitendinosus m, and semimembransosus m. become injured

A: dorsiflexes and inverts foot
O: laterla condyle and lateral margin of proximal half of tibia, interosseous membrane
I: medial cuneiform, metatarsal I

part of the distal group of tarsal bones
insertions point for tibialis anterior m.

A: plantar flexes foot, flexes knee (walking/running/jumping)
O: condyles and popliteal surface of femur, lateral supracondylar line, capsule of knee joint
I: calcaneus

the posterior side of the femur that is flat or slightly depressed

A: plantar flexes foot
O: posterior surface of head and proximal one-fourth of fibula, middle one-third of tibia, interosseous membrane
I: calcaneus

achilles tendon
the strongest tendon in the body
common site of athletic injury from sudden stress