Summary Lower Extremity Muscle Chart

Muscle Proximal Distal Attachment Innervation Actions
HIP, Knee,
Attachment
Ankle, Foot
Gluteus Maximus Ilium posterior to Most fibers end in Inf gluteal N Extends flexed
posterior gluteal iliotibial tract that (L5, S1, S2) thigh, assists in lat
line, dorsal surface inserts into lat rot, and ABD
of sacrum & coccyx, condyle of tibia; some thigh
sacrotuberous lig fibers insert into
gluteal tuberosity of
femur
Gluteus Medius Lateral surface of Lateral surface of Sup gluteal N ABD and IR thigh
ilium b/w ant and greater trochanter of (L5, S1) at hip; steadies
post gluteal lines femur pelvis on leg
when opp leg is
raised
Gluteus Minimus Lateral surface of Anterior surface of Sup gluteal N ABD and IR thigh
ilium b/w ant and greater trochanter of (L5, S1) at hip; steadies
inf gluteal lines femur pelvis on leg
when opp leg is
raised
Piriformis Anterior surface of Superior border of Branches of Lat rot extended
sacral segments 2- greater trochanter of anterior thigh, ABD flexed
4, sacrotuberous lig femur rami, S1, S2 thigh at hip;
steadies femoral
head in
acetabulum
Gemellus Superior Sup: ischial spine Medial surface of Sup: N to Lat rot extended
& Inferior Inf: ischial greater trochanter obturator thigh and ABD
tuberosity (trochanteric fossa) of internus (L5, flexed thigh;
femur S1) steady femoral
Inf: N to head in
quad femoris acetabulum
(L5, S1)
Obturator Internus Pelvic surface of Medial surface of Nerve to Lat rot extended
obturator greater trochanter of obturator thigh, ABD flexed
membrane and femur internus (L5, thigh at hip
surrounding bone S1)
Obturator Externus Margins of Trochanteric fossa of Obturator N Lat rot thigh, stab
obturator foramen, femur (L3, L4) head of femur in
obturator acetabulum
membrane
Tensor Fascia Lata ASIS & anterior part IT tract that attaches Superior ABD & flexion of
of iliac crest to lat condyle of tibia gluteal N femur and IR
Gracilis Pubic symphysis & Sup part of medial Obturator N ADD thigh, flexes

, inf pubic ramus surface of tibia and IR leg
Iliacus Iliac crest, iliac Psoas major T, lesser Femoral N Flexes hip joint
fossa, ala of sacrum, trochanter where it (L2, L3) and in stab hip
& ant SI lig joins w/ and inserts as joint; acts w/
the iliopsoas muscle psoas major
Psoas Major Anterior surfaces Lesser trochanter Ventral Rami Flexes and ER hip,
and lower borders where it inserts as the of L1, L2, L3, and flex/lat flex of
of transverse iliopsoas Tendon L4 L spine
processes of T12-L5
Psoas Minor T12-L1 vert body Iliopectineal arch L1 spinal N Flex and lat flex of
and disc L spine; assists in
upward rot of
pelvis
Pectineus Pectin pubis of sup Pectineal line of femur Femoral N ABD and flexion
pubic ramus (L2, L3); of hip
sometimes
obturator N
(L3, L4)
Quadratus Femoris Lateral border of Quadrate tubercle on N to Lat rot thigh,
ischial tuberosity intertrochanteric crest quadratus steadies femoral
of femur & area inf to femoris (L5, head in
it S1) acetabulum
Semimembranosus Ischial tuberosity Post part of med Tibial division Extend thigh; flex
condyle of tibia. of sciatic N leg & rot it med
Reflected attachment part of tibia when knee is
forms oblique (L5, S1, S2) flexed. When
popliteal lig (to lat thigh & leg are
femoral condyle) flexed, these
muscles can
extend trunk
Semitendinosus Ischial tuberosity Medial surface of sup Tibial division Ext thigh; flex leg
part of tibia of sciatic N & rot it med when
part of tibia knee is flexed.
(L5, S1, S2) When thigh & leg
are flexed, these
muscles can
extend trunk
Biceps Femoris LH: ischial Lat side of head of LH: tibial Flexes leg & rot it
tuberosity fibula. Tendon is split division of lat when knee is
SH: linea aspera & at this site by fibular sciatic N (L5, flexed; ext thigh
lat supracondylar collateral lig of knee S1, S2) (accelerating
line of femur SH: common mass during 1st
fibular step of gait)