Leg Muscles Flashcards
(24 cards)
Anterior compartment
Tibialis anterior (TA) Extensor hallucis longus (EHL) Extensor digitorum longus (EDL) Fibularis tertius
Lateral compartment
Fibularis longus (FL) Fibularis brevis (FB)
Tibialis anterior
Origin : lateral condyle and superior 2/3 of lateral surface of tibia and interosseous membrane
Insertion : medial and inferior surfaces of medial cuneiform and base of 1st metatarsal
Innervation - deep fibular nerve L4, L5
Action - dorsiflexes ankle; inverts foot; supports medial longitudinal arch of foot
Extensor hallucis longus (EHL)
Origin : middle part of anterior surface of fibula and interosseous membrane
Insertion : dorsal aspect of base of distal phalanx of great toe (hallux)
Innervation : deep fibular nerve L5, S1
Action : extends great toe; dorsiflexes ankle
Extensor digitorum longus (EDL)
Origin: lateral condyle of tibia and superior 2/3 of anterior surface of fibula and interosseous membrane
Insertion : middle and distal phalanges of lateral four digits
Innervation : deep fibular nerve L5, S1
Action : extends lateral four digits; dorsiflexes ankle
Fibularis tertius
Origin : inferior third of anterior surface of fibula and interosseous membrane
Insertion: dorsum of base of 5th metatarsal
Innervation : deep fibular nerve L5, S1
Action : dorsiflexes ankle; aids in eversion of foot
Fibularis longus
Origin : head and superior two thirds of lateral surface of fibula
Insertion : base of 1st metatarsal and medial cuneiform
Innervation: superficial fibular nerve L5, S1, S2,
Action : evert foot; weakly plantar flex ankle; supports transverse arch of foot
Fibularis brevis (FB)
Origin : middle part of lateral surface of fibula
Insertion : dorsal surface of tuberosity of base of 5th metatarsal
Innervation : superficial fibular nerve L5, S1, S2?
Action : evert foot; weakly plantarflex ankle
Gastrocnemius
Origin : lateral head - lateral aspect of lateral condyle of femur
medial head - popliteal surface of femur, superior to medial condyle
Insertion : calcaneal tendon
Innervation : tibial nerve (S1, S2)
Action : plantarflexes ankle when knee is extended; raises heel during walking; flexes knee joint
Soleus
Origin: posterior aspect of head of fibula, superior quarter of posterior surface of fibula, soleal line, medial border of tibia
Insertion : calcaneal tendon
Innervation : tibial nerve S1, S2
Action : plantarflexes ankle; steadies leg on foot
Plantaris
Origin : inferior end of lateral supra condylar line of femur and oblique popliteal ligament
Insertion : calcaneal tendon
Innervation : tibial nerve S1, S2
Action : weakly assists gastrocnemius in plantar flexing ankle; function probably mainly proprioceptive
Flexor hallucis longus
Origin : inferior two thirds of posterior surface of fibula and inferior part of interosseous membrane
Insertion : base of distal phalanx of great toe (hallux)
Innervation : tibial nerve S2, S3
Action: flexes great toe at all joints; weakly plantarflexes ankle; supports medial longitudinal arch of foot
Flexor digitorum longus
Origin : medial part of posterior surface of tibia inferior to soleal line and by a broad tendon of fibula
Insertion : bases of distal phalanges of lateral four digits
Innervation : tibial nerve S2, S3
Action : flexes lateral four digits; plantarflexes ankle; supports longitudinal arches of foot
Tibialis posterior
Origin: interosseous membrane, posterior surface of tibia inferior to soleal line, posterior surface of fibula
Insertion : primarily to tuberosity of navicular; also to cuneiform cuboid, bases of 2-4 metatarsals
Innervation : tibial nerve L4, L5
Action : plantarflexes ankles ; inverts foot, supports medial longitudinal arch of foot
Abductor hallucis
Origin : medial tubercle of tuberosity of calcaneus, flexor retinaculum, and plantar aponeurosis
Insertion : medial sides of base of proximal phalanx of 1st digit
Innervation : medial plantar nerve S2, S3
Action : abducts and flexes great toe
Flexor digitorum brevis
Origin : medial tubercle of tuberosity of calcaneus, plantar aponeurosis, and intermuscular septa
Insertion : both sides of middle phalanges of lateral four digits
Innervation : medial plantar nerve S2, S3
Action : flexes lateral four digits
Abductir digiti minimi
Origin : medial and lateral tubercles of tuberosity of calcaneus, plantar aponeurosis, and intermuscular septa
Insertion : lateral side of bacon proximal phalanx of 5th digit
Innervation : lateral plantar nerve S2, S3
Action : abducts and flexes 5th digit
Quadratus plantae
Origin : medial surface and lateral margin of plantar surface of calcaneus
Insertion : posterolateral margin of tendon of flexor digitorum longus
Innervation : lateral plantar nerve S2, S3
Action : assists flexor digitorum longus in flexing lateral four digits
Lumbricals
Origin : tendons of flexor digitorum longus
Insertion : medial aspect of expansion over lateral four digits
Innervation : medial one - medial plantar nerve S2,S3
Lateral three - lateral plantar nerve S2,S3
Action - flex proximal phalanges; extend middle and distal phalanges of lateral four digits
Flexor hallucis brevis
Origin : plantar surface of cuboid and lateral cuneiform
Insertion : both sides of base of proximal phalanx of great toe
Innervation : medial plantar nerve S2, S3
Action : flexes proximal phalanx of great toe
Adductor hallucis
Origin : oblique head : bases of metatarsals 2-4
transverse head : plantar ligaments of 3-5 metatarsophalangeal joint
Insertion : tendons of both heads attach to lateral side of base of proximal phalanx of 1st digit
Innervation : deep branch of lateral plantar nerve S2, S3
Action : adducts 1st digit; assists in maintaining transverse arch of foot
Flexor digiti minimi brevis
Origin : base of 5th metatarsal
Insertion : base of proximal phalanx of 5th digit
Innervation : superficial branch of lateral plantar nerve S2, S3
Action : flexes proximal phalanx of 5th digit, thereby assisting with its flexion
Plantar interossei (three muscles)
Origin : bases and medusa sides of metatarsals 3-5
Insertion : medial sides of bases of proximal phalanges of 3-5th digits
Innervation - lateral plantar nerve S2, S3
Action - adduct digits 3-5 and flex metatarsophalangeal joint
Dorsal interossei (four muscles)
Origin : adjacent sides of metatarsals 1-5
Insertion : first- medial side of proximal phalanx of 2nd digit
second to fourth - laters, sides of 2-4 digits
Innervation : lateral plantar nerves S2, S3
Action : Abduct digits 2-4 and flex metatarsophalangeal joints
