Leg And Foot Muscles Flashcards
Extensor hallucis longus Origin? Insertion? Innervation? Action?
O: Middle part of anterior surface of fibula and interosseous membrane
I: Dorsal aspect of base of distal phalanx of great toe (hallux)
Inner: Deep fibular nerve (L5-S1)
Action: Extends great toe; dorsiflexes ankle
Tibialis anterior Origin? Insertion? Innervation? Action?
O: Lateral condyle and superior half of lateral surface of tibia and interosseous membrane
I: Medial and inferior surfaces of medial cuneiform and base of 1st metatarsal
Inner: Deep fibular nerve (L4-L5)
Action: Dorsiflexes ankle; inverts foot; supports medial longitudinal arch of foot
Extensor digitorum longus Origin? Insertion? Innervation? Action?
O: Lateral condyle of tibia and superior three fourths of anterior surface of interosseous membrane
I: Middle and distal phalanges of lateral four digits
Inner: Deep fibular nerve (L5-S1)
Action: Extends lateral four digits; dorsiflexes ankle
Fibularis tertius Origin? Insertion? Innervation? Action?
O: Inferior third of anterior surface of fibula and interosseous membrane
I: Dorsum of base of 5th metatarsal
Inner: Deep fibular nerve (L5-S1)
Action: Dorsiflexes ankle; aids in eversion of foot
Fibularis longus Origin? Insertion? Innervation? Action?
O: Head and superior two thirds of lateral surface of fibula
I: Base of 1st metatarsal and medial cuneiform
Inner: Superficial fibular nerve (L5-S2)
Action: Evert foot; weakly plantarflex ankle. FL supports transverse arch of foot
Fibularis brevis Origin? Insertion? Innervation? Action?
O: Inferior two thirds of lateral surface of fibula
I: Dorsal surface of tuberosity of base of 5th metatarsal
Inner: Superficial fibular nerve (L5-S2)
Action: ????
Gastrocnemius Origin? Insertion? Innervation? Action?
O: Lateral head-> Lateral aspect of lateral condyle of femur
Medial head-> Popliteal surface of femur, superior to medial condyle
I: Posterior surface of calcaneus via calcaneal tendon
Inner: Tibial nerve (S1 and S2)
Action: Plantarflexes ankle when knee is extended; raises heel during walking and flexes leg and knee joint
Soleus Origin? Insertion? Innervation? Action?
O: Posterior aspect of head of fibula, superior quarter of posterior surface of fibula, soleal line, and medial border of tibia
I: Posterior surface of calcaneus via calcaneal tendon
Inner: Tibial nerve (S1 and S2)
Action: Plantarflexes ankle; steadies leg on foot
Plantaris Origin? Insertion? Innervation? Action?
O: Inferior end of lateral supracondylar line of femur and oblique popliteal ligament
I: Posterior surface of calcaneus via calcaneal tendon
Inner: Tibial nerve (S1 and S2)
Action: Weakly assists gastrocnemius in plantarflexing ankle
Flexor hallucis longus Origin? Insertion? Innervation? Action?
O: Inferior two thirds of posterior surface of fibula and inferior part of interosseous membrane
I: Base of distal phalanx of great toe
Inner: Tibial nerve (S2-S3)
Action: Flexes great toe at all joints; weakly plantarflexes ankle; supports medial longitudinal arch of foot
Flexor digitorum longus Origin? Insertion? Innervation? Action?
O: Medial part of posterior surface of tibia inferior to soleal line and by a broad tendon to fibula
I: Bases of distal phalanges of lateral four digits
Inner: Tibial nerve (S2-S3)
Action: Flexes lateral four digits; Plantarflexes ankle; supports longitudinal arches of foot
Tibialis posterior Origin? Insertion? Innervation? Action?
O: Interosseous membrane, posterior surface of tibia inferior to soleal line and posterior surface of fibula
I: Primarily to tuberosity of navicular; also to cuneiforms, cuboid and bases of 2-4th metatarsals
Inner: Tibial nerve (L4-L5)
Action: Plantarflexes ankle; inverts foot; supports medial longitudinal arch of foot
Abductor hallucis Origin? Insertion? Innervation? Action?
O: Medial tubercle of tuberosity of calcaneus, flexor retinaculum, and plantar aponeurosis
I: Medial side of base of proximal phalanx of 1st digit
Inner: Medial plantar nerve (S2-S3)
Action: Abducts and flexes 1st digit
Flexor digitorum brevis Origin? Insertion? Innervation? Action?
O: Medial tubercle of tuberosity of calcaneus, plantar aponeurosis, and intermuscular septa
I: Both sides of middle phalanges of lateral four digits
Inner: Medial plantar nerve (S2-S3)
Action: Flexes lateral four digits
Abductor digiti minimi Origin? Insertion? Innervation? Action?
O: Medial and lateral tubercles of tuberosity of calcaneus, plantar aponeurosis, and intermuscular septa
I: Lateral side of base of proximal phalanx of 5th digit
Inner: Lateral plantar nerve (S2-S3)
Action: Abducts and flexes 5th digit
Quadratus plantae Origin? Insertion? Innervation? Action?
O: Medial surface and lateral margin of plantar surface of calcaneus
I: Posterolateral margin of tendon of flexor digitorum longus
Inner: Lateral plantar nerve (S2-S3)
Action: Assists flexor digitorum longus in flexing lateral four digits
Lumbricals Origin? Insertion? Innervation? Action?
O: Tendons of flexor digitorum longus
I: Medial aspect of expansion over lateral four digits
Inner: 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? Insertion? Innervation? Action?
O: Plantar surfaces of cuboid and lateral cuneiform
I: Both sides of base of proximal phalanx of 1st digit
Inner: Medial plantar nerve (S2-S3)
Action: Flexes proximal phalanx of 1st digit
Adductor hallucis Origin? Insertion? Innervation? Action?
O: Oblique head-> Bases of metatarsals 2-4
Transverse head-> plantar ligaments of 3-5th metatarsophalangeal joints
I: Tendons of both heads attach to lateral side of base of proximal phalanx of 1st digit
Inner: Deep branch of lateral plantar nerve (S2-S3)
Action: Adducts 1st digit; assists in maintaining transverse arch of foot
Flexor digiti minimi brevis Origin? Insertion? Innervation? Action?
O: Base of 5th metatarsal
I: Base of proximal phalanx of 5th digit
Inner: Superficial branch of lateral plantar nerve (S2-S3)
Action: Flexes proximal phalanx of 5th digit, thereby assisting with its flexion
Plantar interossei (3) Origin? Insertion? Innervation? Action?
O: Bases and medial sides of metatarsals 3-5
I: Medial sides of bases of proximal phalanges of 3-5th digits
Inner: Lateral plantar nerve (S2-S3)
Action: Adduct digits 3-5 and flex metatarsophalangeal joints
Dorsal interossei (4) Origin? Insertion? Innervation? Action?
O: Adjacent sides of metatarsals 1-5
I: First-> medial side of proximal phalanx of 2nd digit
Second-Fourth-> lateral sides of 2-4th digits
Inner: Lateral plantar nerve (S2-S3)
Action: Abduct digits 2-4 and flex metatarsophalangeal joints
