Exam 3: Muscles Flashcards
Quadratus Lumborum
Origin: Lumbar transverse processes; rib 12
Insertion: Iliac Crest
Nerve: Lumbar Plexus (T12-L4)
Action: Extends, laterally flexes vertebral column
Psoas Major
Origin: Vertebral bodies, IV discs and transverse
processes of T12; L1-5
Insertion: Lesser trochanter of femur
Nerve: Lumbar Plexus (L1, L2, L3)
Action: Flexes thigh; stabilizes trunk
Iliacus
Origin: Iliac fossa and crest
Insertion: Lesser trochanter of femur
Nerve: Femoral nerve
Action: Flexes hip; stabilizes trunk
Piriformis
Origin: Anterior surface of sacrum; sacrotuberous
ligament
Insertion: Greater trochanter of femur
Nerve: Nerve to piriformis (S1, S2)
Action: Laterally rotates thigh; stabilizes femoral head in
acetabulum
Obturator Internus
Origin: Deep surface of obturator membrane and
surrounding bone
Insertion: Greater trochanter of femur
Nerve: Nerve to obturator internus
Action: Laterally rotates thigh; stabilizes femoral head in
acetabulum
Obturator Externus
Origin: External surface of obturator membrane and
surrounding bone
Insertion: Trochanteric fossa of femur
Nerve: Obturator nerve
Action: Laterally rotates thigh; stabilizes femoral head in
acetabulum
Superior gemellus
Origin: Ischial spine
Insertion: Greater trochanter of femur
Nerve: Nerve to obturator internus
Action: Laterally rotates thigh; stabilizes femoral head in
acetabulum
Inferior gemellus
Origin: Ischial tuberosity
Insertion: Greater trochanter of femur
Nerve: Nerve to quadratus femoris
Action: Laterally rotates thigh; stabilizes femoral head in
acetabulum
Quadratus femoris
Origin: Lateral border of ischial tuberosity
Insertion: Intertrochanteric crest of femur
Nerve: Nerve to quadratus femoris
Action: Laterally rotates thigh; stabilizes femoral head in
acetabulum
Gluteus maximus
Origin: Posterior surface of ilium (posterior gluteal line);
posterior surface of sacrum and coccyx;
sacrotuberous ligament
Insertion: Iliotibial tract (which attaches to lateral condyle
of tibia); gluteal tuberosity of femur
Nerve: Inferior gluteal nerve
Action: Extends, laterally rotates thigh
Gluteus medius
Origin: External surface of ilium between anterior and
posterior gluteal lines
Insertion: Greater trochanter of femur
Nerve: Superior gluteal nerve
Action: Abducts and medially rotates thigh; keeps pelvis
level during walking (prevents contralateral
pelvic drop)
Gluteus minimus
Origin: External surface of ilium between anterior and
inferior gluteal lines
Insertion: Greater trochanter of femur
Nerve: Superior gluteal nerve
Action: Abducts and medially rotates thigh; keeps pelvis
level during walking (prevents contralateral
pelvic drop)
Tensor facsiae latae
Origin: ASIS; Iliac crest
Insertion: Iliotibial tract (which attaches to lateral condyle
of tibia)
Nerve: Superior gluteal nerve
Action: Flexes and medially rotates thigh; tenses the
fascia latae of the thigh
Rectus femoris
Origin: AIIS
Insertion: Patella via quadriceps tendon (directly) & tibial
tuberosity via patellar ligament (indirectly)
Nerve: Femoral nerve
Action: Flexes thigh; extends knee
Vastus lateralis
Origin: Greater trochanter of femur; lateral lip of linea
aspera
Insertion: Patella via quadriceps tendon (directly) & tibial
tuberosity via patellar ligament (indirectly)
Nerve: Femoral nerve
Action: Extends knee/leg
Vastus medialis
Origin: Intertrochanteric line; medial lip of linea aspera
Insertion: Patella via quadriceps tendon (directly) & tibial
tuberosity via patellar ligament (indirectly)
Nerve: Femoral nerve
Action: Extends knee/leg
Vastus intermedius
Origin: Anterior & lateral surfaces of femoral diaphysis
(shaft)
Insertion: Patella via quadriceps tendon (directly) & tibial
tuberosity via patellar ligament (indirectly)
Nerve: Femoral nerve
Action: Extends knee/leg
Sartorius
Origin: ASIS
Insertion: Superior part of medial surface of tibia
Nerve: Femoral nerve
Action: Flexes, abducts and laterally rotates thigh; flexes
leg
Pectineus
Origin: Superior pubic ramus
Insertion: Pectineal line of femur (inferior to lesser
trochanter)
Nerve: Femoral nerve
Action: Adducts and flexes thigh; assists with medial
rotation of thigh
Gracilis
Origin: Body and inferior ramus of pubis
Insertion: Medial surface of proximal tibia
Nerve: Obturator nerve
Action: Adducts thigh and flexes knee
Adductor longus
Origin: Body of pubis
Insertion: Linea aspera - middle 1/3
Nerve: Obturator nerve
Action: Adducts thigh
Adductor brevis
Origin: Body and inferior ramus of pubis
Insertion: Linea aspera - superior 1/3
Nerve: Obturator nerve
Action: Adducts thigh
Adductor magnus - adductor part
Origin: Ischiopubic ramus
Insertion: Gluteal tuberosity and proximal linea aspera
Nerve: Obturator nerve
Action: Adducts and flexes thigh
Adductor magnus - hamstring part
Origin: Ischial tuberosity
Insertion: Adductor tubercle of femur
Nerve: Tibial division of sciatic nerve
Action: Adducts and extends thigh
Semitendinosus
Origin: Ischial Tuberosity
Insertion: Medial surface of proximal tibia
Nerve: Tibial division of sciatic nerve
Action: Extends hip and flexes knee
Semimembranosus
Origin: Ischial Tuberosity
Insertion: Posterior aspect of medial condyle of tibia
Nerve: Tibial division of sciatic nerve
Action: Extends hip and flexes knee
Biceps femoris - long head
Origin: Ischial Tuberosity
Insertion: Head of fibula
Nerve: Tibial division of sciatic nerve
Action: Extends hip and flexes knee
Biceps femoris - short head
Origin: Linea aspera
Insertion: Head of fibula
Nerve: Common fibular division of sciatic nerve
Action: Flexes knee
Gastrocnemius
Origin: Lateral head: lateral femoral condyle
Medial head: popliteal surface of femur
Insertion: Calcaneal tuberosity - posterior surface of
calcaneus via calcaneal tendon
Nerve: Tibial nerve
Action: Flexes knee; plantar flexes foot
Soleus
Origin: Soleal line of tibia; posterior aspect of fibular
head
Insertion: Calcaneal tuberosity - posterior surface of
calcaneus via calcaneal tendon
Nerve: Tibial nerve
Action: Powerful plantar flexor of the foot
Plantaris
Origin: Lateral supracondylar line of the femur
Insertion: Calcaneal tuberosity - posterior surface of
calcaneus via calcaneal tendon
Nerve: Tibial nerve
Action: Weak plantar flexor of the foot
Popliteus
Origin: Lateral condyle of femur; lateral meniscus
Insertion: Posterior surface of proximal tibia; superior to
soleal line
Nerve: Tibial nerve
Action: “Unlocks” knee(laterally rotates femur on fixed
tibia)
Flexor digitorum longus
Origin: Medial side of posterior surface of tibia
Insertion: Plantar surface of bases of distal phalanges of
lateral 4 digits
Nerve: Tibial nerve
Action: Flexes MTP, PIP, & DIP of lateral 4 toes; Plantar
flexion of foot
Flexor hallucis longus
Origin: Posterior surface of fibula and interosseous
membrane
Insertion: Plantar surface of distal phalanx of hallux
Nerve: Tibial nerve
Action: Flexes MTP & IP of hallux; Plantar flexion of foot
Tibialis posterior
Origin: Posterior surface of interosseous membrane,
tibia and fibula
Insertion: Primarily navicular; also cuneiforms, cuboid
and 2nd-4th metatarsals
Nerve: Tibial nerve
Action: Plantar flexion and inversion of foot
Tibialis anterior
Origin: Lateral condyle,lateral surface of tibia and
interosseous membrane
Insertion: Medial cuneiform;base of 1st metatarsal
Nerve: Deep fibular nerve (also known as deep
peroneal nerve)
Action: Dorsiflexes ankle and inverts foot
Extensor digitorum longus
Origin: Proximal 2/3 of anterior surface of fibula and
interosseous membrane; Lateral condyle of tibia
Insertion: Middle and distal phalanges of digits 2-5
Nerve: Deep fibular nerve (also known as deep
peroneal nerve)
Action: Extends lateral 4 digits; Dorsiflexes ankle
Extensor digitorum brevis
Origin: Dorsal surface of calcaneus
Insertion: Extensor expansions of digits 2-4
Nerve: Deep fibular nerve (also known as deep
peroneal nerve)
Action: Assists extensor digitorum longus in extending
digits 2-4
Extensor hallucis longus
Origin: Anterior surface of fibula and interosseous
membrane
Insertion: Base of distal phalanx and hallux
Nerve: Deep fibular nerve (also known as deep
peroneal nerve)
Action: Extends hallux; Dorsiflexes ankle
Extensor hallucis brevis
Origin: Dorsal surface of calcaneus
Insertion: Base of proximal phalanx of hallux
Nerve: Deep fibular nerve (also known as deep
peroneal nerve)
Action: Assists extensor hallucis longus in extending hallux
Fibularis tertius (Peroneus tertius)
Origin: Inferior 1/3 of anterior surface of fibula and
interosseous membrane
Insertion: Base of 5th metatarsal
Nerve: Deep fibular nerve (also known as deep
peroneal nerve)
Action: Dorsiflexes ankle, assists in eversion of foot
Fibularis longus (Peroneus longus)
Origin: Head and superior 2/3 of lateral side of fibula
Insertion: Base of 1st metatarsal and medial cuneiform
Nerve: Superficial fibular nerve (also known as
superficial peroneal nerve)
Action: Everts foot; Weakly plantar flexes ankle
Fibularis brevis (Peroneus brevis)
Origin: Inferior 2/3 of lateral surface of fibula
Insertion: Tuberosity at base of metatarsal 5
Nerve: Superficial fibular nerve (also known as
superficial peroneal nerve)
Action: Everts foot; Weakly plantar flexes ankle
Abductor hallucis (1st layer)
Origin: Calcaneal tuberosity, plantar aponeurosis
Insertion: Base of proximal phalanx of hallux
Nerve: Medial plantar nerve
Action: Abducts and flexes hallux
Flexor digitorum brevis (1st layer)
Origin: Calcaneal tuberosity, plantar aponeurosis
Insertion: Middle phalanges of digits 2-5
Nerve: Medial plantar nerve
Action: Flexes lateral 4 toes at proximal IP joints
Flexor hallucis brevis (3rd layer)
Origin: Cuboid, lateral cuneiform
Insertion: Sides of proximal phalanx of hallux
Nerve: Medial plantar nerve
Action: Flexes MTP joint of hallux
Abductor digiti minimi (1st layer)
Origin: Calcaneal tuberosity, plantar aponeurosis
Insertion: Proximal phalanx of 5th digit
Nerve: Lateral plantar nerve
Action: Abducts / flexes digit 5
Quadratus plantae (2nd layer)
Origin: Plantar surface of calcaneus
Insertion: Lateral side of tendon of flexor digitorum
longus
Nerve: Lateral plantar nerve
Action: Assists flexor digitorum longus in flexing digits 2-
5
Adductor hallucis (3rd layer)
Origin: Transverse Head - lateral 3 MTP joints
Oblique Head - bases of metatarsals 2-4
Insertion: Base of proximal phalanx of hallux
Nerve: Lateral plantar nerve
Action: Adducts hallux
Flexor digiti minimi brevis (3rd layer)
Origin: Base of 5th metatarsal
Insertion: Proximal phalanx of digit 5
Nerve: Lateral plantar nerve
Action: Flexes MTP joint of digit 5
3 Plantar Interossei (4th layer)
Origin: Medial sides of metatarsals 3-5
Insertion: Medial sides of bases of proximal phalanges
of digits 3-5
Nerve: Lateral plantar nerve
Action: Adduct digits 3-5 (PAD)
4 Dorsal Interossei (4th layer)
Origin: Adjacent sides of metatarsals 1-5
Insertion: 1st - Medial side of proximal phalanx ofdigit 2
2nd - 4th - lateral sides of proximal phalanges
of digits 2-4
Nerve: Lateral plantar nerve
Action: Abduct digits 2-4 (DAB)
4 Lumbricals (4th layer)
Origin: Tendons of flexor digitorum longus
Insertion: Extensor expansions of digits 2-5
Nerve: 1st - Medial plantar nerve
2nd-4th - Lateral plantar nerve
Action: Flex MTP joint; extend IP joints
