Extremidades bajas

Iliopsoas
Origin
Iliacus – inner surface of the ilium
Psoas major and minor – lower borders of the transverse
processes – L1-L5; sides of the bodies of the last thoracic
vertebrae – T12 and lumbar L1-L5; intervertebral fibrocartilages,
and the base of the sacrum
Insertion
Iliacus and psoas major: lesser trochanter of the femur and the shaft
just below
Functions
Hip FlexionExternal rotation of the femur
The iliopsoas is commonly referred to as if it were one muscle but it is
actually composed of the iliacus, the psoas major and psoas minor.
The iliopsoas muscle is powerful in actions such as raising the legs from the floor while in
a supine position. Leg raises are primarily hip flexion and not abdominal action.

Sartorius
Origin
Anterior superior iliac spine andnotch just below the spine
Insertion
Anterior medial condyle of the tibia
Functions
Hip flexion
Knee flexion
External rotation of the thigh as it flexes the hip and knee
The sartorius is a two joint muscle effective as a hip flexor or as a knee
flexor. It is weak when both actions take place at the same time.

Rectus Femoris
Origin
Anterior inferior iliac spine of the ilium andgroove (posterior) above the
acetabulum
Insertion
Superior aspect of the patella and patellar tendon to the tibial tuberosity
Functions
Hip flexion
Knee extension
Generally, a muscle’s ability to exert force decreases as it shortens. This
explains why the rectus femoris muscle is a powerful extensor of the knee
when the hip is extended but it is weak when the hip is flexed. The rectusfemoris is best developed by performing hip flexion exercises or knee
extension exercises.

Tensor Faciae Latae
Origin
Anterior iliac crest and surface of the ilium just below the crest
Insertion
One fourth of the way down the thigh into the iliotibial tract, which in
turn inserts onto Gerdy’s tubercle of the anterolateral tibial condyle
Functions
Hip abduction
Hip flexionInternal rotation of the hip as it flexes
This muscle aids in preventing external rotation of the hip as it is flexed by other flexor
muscles, the movement is important in helping direct the leg forward so that the foot is
placed straight forward in walking and running.
Hip abduction exercises help develop the tensor faciae latae muscle.

Six deep lateral rotator muscles
Piriformis; GemellusSuperior; Gemellus Inferior; Obturator
Externus; Obturator Internus; Quadratus Femoris
Origin (collectively)
Anterior sacrum, posterior portion of the ischium and the obturator
foramen
Insertion
Superior and posterior aspect of the greater trochanter
Functions
External rotation of the hip
The six rotators are used powerfully in movements of external
rotation of the femur, as in sports in whichthe individual takes off on
one leg from a preliminary internal rotation. Throwing a baseball and
swinging a baseball bat are good examples.
The sciatic nerve enters the lower limb by exiting the
pelvis through the greater sciatic foramen below the
piriformis muscle. It descends midway in the greater
trochanter of the femur and the tuberosity of the ischium,
and along the back of the thighto about its lower third,
where it divides into two branches, the tibial and common
peroneal nerves. When it occurs at the plexus, the
common peroneal nerve usually pierces the piriformis
muscle.

Gluteus Minimus
Origin
Lateral surface of the ilium just below the origin of the gluteus
medius
Insertion
Anterior surface of the great trochanter of the femur
Functions
Hip abductionInternal rotation as the femur abducts
Both the gluteus minimus and gluteus medius are used in powerfully
maintaining proper hip abduction while running.
Hip abduction exercises best strengthens the gluteus minimus.

Gluteus medius
Origin
Lateral surface of the ilium just below the crest
Insertion
Posterior and middle surfaces of the greater trochanter of the femur
Functions...