Lower Body Muscles Flashcards
Piriformis
A-externally rotate hip, abduct hip when flexed
O-anterior surface of sacrum
I-sup aspect of greater trochanter
Quadratus Femoris
A-externally rotate hip
O-lateral border of ischial tuberosity
I-Intertrochanteric crest, between the
greater and lesser trochanters
Gluteus Maximus
A-All fibers:
Extend the hip
Laterally rotate the hip
Abduct the hip
A-Lower fibers:
Adduct the hip
O-Coccyx, edge of sacrum, posterior iliac
crest, sacrotuberous and sacroiliac
ligaments
I-Iliotibial tract (upper fibers) and gluteal
tuberosity (lower fibers)
Gluteus Medius
A-All fibers: Abduct the hip
Anterior fibers: Flex the hip
Medially/Internally rotate the hip
Posterior fibers: Extend the hip, Laterally rotate the hip
O-Gluteal surface of ilium, between posterior
and anterior gluteal lines, just below the
iliac crest
I-Lateral aspect of greater trochanter
Gluteus Minimus
A-Abduct the hip
Medially/Internally rotate the hip, Flex the hip
O-Gluteal surface of the ilium between the
anterior and inferior gluteal lines
I-Anterior aspect of greater trochanter
Illiacus
A-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
O-Iliac fossa
I-Lesser trochanter
Psoas Major
A-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
O-Bodies and transverse processes of lumbar vertebrae
I-Lesser trochanter
Tensor Fasciae Latae and IT Tract
A-Flex the hip
Medially rotate the hip
Abduct the hip
O-Iliac crest, posterior to the ASIS
I-Iliotibial tract
Rectus Femoris
A-Extend the knee
Flex the hip
O-Anterior inferior iliac spine (AIIS)
I-Tibial tuberosity (via the patella and
patellar ligament)
Vastus Medialis, Intermedius, and Lateralis
A-Extend the knee
O-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
I-Tibial tuberosity (via the patella and patellar
ligament)
Sartorius
A Flex the hip
Laterally rotate the hip
Abduct the hip
Flex the knee
Medially rotate the flexed knee
O Anterior superior iliac spine (ASIS)
I Proximal, medial shaft of the tibia
at pes anserinus tendon
Biceps Femoris
A Flex the knee
Laterally rotate the flexed knee
Long head: Extend the hip
Long head: Assist to laterally rotate the hip
Tilt the pelvis posteriorly
O Long head: Ischial tuberosity
Short head: Lateral lip of linea aspera
I Head of the fibula
Semitendinosus
A Flex the knee
Medially rotate the flexed knee
Extend the hip
Assist to medially rotate the hip
Tilt the pelvis posteriorly
O Ischial tuberosity
I Proximal, medial shaft of the tibia at pes anserinus
tendon
Semimembranosus
A- Flex knee,
Medially rotate the flexed knee
Extend the hip
Assist to medially rotate the hip
Tilt the pelvis posteriorly
O Ischial tuberosity
I Posterior aspect of medial condyle of tibia
Adductor Longus
A Adduct the hip
Medially rotate the hip
Assist to flex the hip
O Pubic tubercle
I Medial lip of linea aspera
Adductor Magnus
A Adduct the hip
Medially rotate the hip
Assist to flex the hip
Posterior fibers:
Extend the hip
O Inferior ramus of the pubis, ramus of
ischium, and ischial tuberosity
I Medial lip of linea aspera and adductor
tubercle
Gracilis
A Adduct the hip
Medially rotate the hip
Flex the knee
Medially rotate the flexed knee
O Inferior ramus of pubis
I Proximal, medial shaft of tibia at pes
anserinus tendon
Gastrocnemius
A Flex the knee
Plantar flex the ankle
O Condyles of the femur, posterior surfaces
I Calcaneus via calcaneal tendon
Soleus
A Plantar flex the ankle
O Soleal line; proximal, posterior surface
of tibia; and posterior aspect of head of
fibula
I Calcaneus via calcaneal tendon
Plantaris
A Weak plantar flexion of the
ankle
Weak flexion of the knee
O Lateral supracondylar line of
femur
I Calcaneus via calcaneal tendon
Tibialis Posterior
A Invert the foot
Plantar flex the ankle
O Proximal, posterior shafts of tibia and
fibula; and interosseous membrane
I Five tarsal bones (navicular, medial
cuneiform, middle cuneiform, lateral
cuneiform, cuboid, & bases of 2-4
metatarsals
Flexor Digitorum Longus
A Flex the second through fifth toes (MTP
& IP joints)
Weak plantar flexion of ankle
Invert the foot
O Middle, posterior surface of tibia
I Distal phalanges of second through fifth
toes
Flexor Hallucis Longus
A Flex the first toe (MTP & IP joints)
Weak plantar flexion of ankle
Invert the foot
O Middle half of posterior fibula
I Distal phalanx of first toe
Fibularis Longus
A Evert the foot
Assist to plantar flex the ankle
O Head of fibula and proximal two-thirds
of lateral fibula
I Base of the first metatarsal and medial
cuneiform
Fibularis Brevis
A Evert the foot
Assist to plantar flex the ankle
O Distal two-thirds of lateral fibula
I Tuberosity of fifth metatarsal
Tibialis Anterior
A Invert the foot
Dorsiflex the ankle
O Lateral condyle of tibia;
proximal, lateral surface of tibia;
& interosseous membrane
I Medial cuneiform and base of the first
metatarsal
Extensor Digitorum Longus
A Extend the second through fifth toes
(MTP & IP joints)
Dorsiflex the ankle
Evert the foot
O Lateral condyle of tibia; proximal,
anterior shaft of fibula; and
interosseous membrane
I Middle and distal phalanges of second
through fifth toes
Extensor Hallucis Longus
A Extend the first toe (MTP & IP joints)
Dorsiflex the ankle
Invert the foot
O Middle, anterior surface of fibula and
interosseous membrane
I Distal phalanx of first toe
Abductor Hallucis
A- abduct great toe
O-medial process of calcaneus and
plantar aponeurosis
I-proximal phalanx of Great toe and
medial Sesamoid bone (plantar)
