LE - Posterior Thigh, Leg and Foot Flashcards
Biceps Femoris
O: Long head – Ischial tuberosity
Short head – Distal aspect of the lateral lip of linea aspera
I: Lateral side of the head of the fibula
A: All heads: Knee flexion and some lateral rotation of the leg at the knee joint;
Long head: Extend the hip, lateral rotation of the thigh at hip joint
N: Long head: Sciatic (tibial branch): L5,S1,S2 Short head: Sciatic (peroneal branch): L5,S1,S2
Semitendinosus
O: Ischial tuberosity
I: Medial surface of proximal tibia at the pes anserine tendon
A: Medially rotate the flexed knee, extend the hip, assist to medial rotate the hip, tilt the pelvic posteriorly
N: Sciatic nerve (tibial branch) (L5, S1, S2)
Semimembranosus
O: Ischial tuberosity
I: Posterior surface of medial tibial condyle (some slips into oblique popliteal ligament inserting on lateral condyle)
A: Medially rotate the flexed knee, extend the hip, assist to medially rotate the hip, tilt the pelvis posteriorly
N: Sciatic nerve (tibial branch) (L5, S1, S2)
Tibialis anterior
O: Lateral condyle of tibia; proximal, lateral surface of tibia and interosseous membrane
I: Medial and inferior surfaces of medial cuneiform and adjacent surfaces on base of 1st metatarsal
A: Dorsiflexion of foot at the ankle joint; inversion of foot; dynamic support of the medial arch of
foot
N: Deep (peroneal) fibular nerve (L4, L5)
Extensor hallucis longus
O: Middle one-half of medial surface of fibula and adjacent surface of interosseous membrane
I: Dorsal surface of base of distal phalanx of great toe A: Extension of the great toe; dorsiflexion of foot at the ankle; invert the foot N: Deep fibular (peroneal) nerve (L5, S1)
Extensor digitorum longus
O: Proximal one-half of medial surface of fibula, interosseous membrane and lateral tibial condyle
I: Bases of distal and middle phalanges of lateral four toes via dorsal digital expansion A: extension of lateral four toes and dorsiflexion of foot (with some eversion) N: Deep fibular (peroneal) nerve (L5, S1)
Extensor digitorum brevis (The portion to the great toe is the Extensor Hallicus Brevis)
O: Superolateral surface of the calcaneus
I: Base of proximal phalanx of great toe and lateral sides of the tendons of extensor digitorum
longus of 2nd to 4th toes
A: Extension of metatarsophalangeal and IP joints of great toe and extension of at 2nd to 4th toes N: Deep fibular (peroneal) (L4, L5, S1)
Gastrocnemius
O: Medial head – posterior surface of distal femur just superior to medial condyle
Lateral head – upper posterolateral surface of lateral femoral condyle
I: Posterior surface of calcaneous via calcaneal tendon A: Plantarflexion at the ankle and flexion at the knee N: Tibial nerve (S1, S2)
Soleus
O: Soleal line and medial border of the tibia; proximal, posterior aspect of the fibula head and adjacent surfaces of neck and proximal shaft; tendinous arch between tibial and fibular attachment
I: Posterior surface of calcaneous via calcaneal tendon A: Plantarflexion at the ankle and flexion at the knee N: tibial nerve (S1, S2)
Plantaris
O: Inferior part of lateral supracondylar line of femur and oblique popliteal ligament of knee
I: Posterior surface of calcaneous via calcaneal tendon
A: plantarflexion at the ankle and flexion at the knee; weak plantar flexion of ankle, weak flexion of the knee
N: Tibial nerve (S1, S2)
Popliteus
O: Lateral surface of the lateral femoral condyle and lateral meniscus
I: Posterior surface of proximal tibial, superior to soleal line
A: stabilizes knee joint (resists lateral rotation of tibia on femur); unlocks knee joint (laterally
rotates femur on fixed tibia or medially rotates the tibia on a fixed femur), weak knee flexion
N: Tibial nerve (L4, L5, S1)
Flexor hallicus longus
O: Middle half of the posterior surface of fibula and adjacent interosseous membrane
I: Plantar surface of distal phalanx of great toe A: flexion of great toe (at MTP and IP joints); Weak plantar flexion of ankle; Invert the foot N: tibial nerve (S2, S3)
Flexor digitorum longus
O: Middle portion of the medial side of posterior surface of the tibia
I: Plantar surfaces of bases of distal phalanges of the lateral four toes
A: flexion of lateral four toes at MTP and IP joints; Weak plantar flexion of the ankle; invert the foot
N: Tibial nerve (S2, S3)
Tibialis Posterior
O: Posterior surfaces of interosseous membrane and adjacent regions of tibia and fibula, inferior to the soleal line
I: Primarily to tuberosity of navicular and adjacent region of medial cuneiform; some tendinous attachment to the MT bases 2-4 and other tarsal bones
A: Inversion and plantarflexion of the foot at TCJ; support medial arch of foot during walking N: Tibial nerve (L4, L5)
Peroneus (fibularis) longus
O: Proximal two-thirds of the lateral surface of the fibula, head of fibula
I: Base of the first metatarsal and medial cuneiform A: Eversion of foot, weak plantarflexion; support arches of foot N: Superficial fibular nerve (L5, S1, S2)
Peroneus (fibularis) brevis
O: Distal two-thirds of the lateral surface of shaft of fibula
I: Tuberosity at the 5th metatarsal A: Eversion of the foot and weak plantarflexion of the ankle N: Superficial fibular nerve (L5, S1, S2)
Peroneus (fibularis) tertius
O: Distal part of medial surface of fibula
I: Dorsomedial surface of base of 5th metatarsal A: dorsiflexion and eversion of the foot N: deep fibular nerve (L5, S1)
Abductor Hallicus (1st Layer)
O:Medial process of calcaneus and plantar aponeurosis
I: Proximal phalanax of the first toe (medial surface) and medial sesamoid bone A: Abduct the first toe (MTP joint) and assist to flex the first toe N: Medial plantar nerve from the tibial nerve (S2, S3)
Flexor digitorum brevis (1st Layer)
O: Medial process of calcaneal tuberosity and plantar aponeurosis
I: Sides of plantar surface of middle phalanges of 2nd to 5th toes A: Flexion of lateral four toes at proximal interphalangeal joint N: medial plantar nerve from the tibial nerve (S2, S3)
Abductor digiti minimi (1st layer)
O: lateral and medial process of calcaneal tuberosity and plantar aponeurosis
I: Lateral side of base of proximal phalanx of little toe A: Abduction and flexion of the 5th toe at the metatarsophalangeal joint N: Lateral plantar nerve from the tibial nerve (S2, S3)
Quadratus plantae (2nd layer)
O: Medial surface of calcaneus and lateral process of calcaneal tuberosity
I: Lateral side of tendon of flexor digitorum longus
A: Assist flexor digitorum longus in flexing 2nd to 5th toes, changing the angle of force application to be more linear
N: Lateral plantar nerve from tibial nerve (S2, S3)
Lumbricales (2nd layer)
O: Tendons of flexor digitorum longus
I: Medial slips into extensor hoods of 2nd to 5th toes
A: Flexion of metatarsophalangeal joint and extension of interphalangeal joints of toes 2-5
N: 1st lumbrical – medial plantar nerve from the tibial nerve (S2, S3)
2nd to 4th lumbrical - lateral plantar nerve from the tibial nerve (S2, S3)
Flexor hallicus brevis (3rd layer)
O: Plantar surface of the cuboid, and lateral cuneiforms; tendon of the tibialis posterior
I: Lateral and medial sides of base of proximal phalanx of the great toe via sesamoids A: Flexion of the metatarsophalangeal joint of the great toe N: Medial plantar nerve from tibial nerve (S2, S3)
Adductor hallicus (3rd layer)
O: Transverse head – ligaments associated with metatarsophalangeal joints of lateral three toes
Oblique head – bases of 2nd to 4th metatarsals
I: Lateral side of base of proximal phalanx of great toe
A: Adduction of the great toe at metatarsophalangeal joint and maintain transverse arch, weak flexion
N: lateral plantar nerve from tibial nerve (S2, S3)
Flexor digiti minimi brevis (3rd layer)
O: Base of the 5th metatarsal and related sheath of fibularis longus tendon
I: Lateral side of base of proximal phalanx of little toe A: Flexion of little toe at the metatarsophalangeal joint N: Lateral plantar nerve from tibial nerve (S2, S3)
Dorsal interossei (4th layer) (4 muscles – bipennate muscles)
O: Sides of adjacent metatarsals
I: Extensor hoods and bases of proximal phalanges of 2nd to 4th toes First: Medial surface of proximal phalanx of 2nd toe Second-fourth: Lateral surfaces of proximal phalanx of 2nd-4th toes
A: Open Chain: Abduction of 2nd to 4th toes at metatarsophalangeal joint; flexion of the metatarsalphalangeal joint and extension of the interphalangeal joint
Closed Chain: resists extension of metatarsophalangeal joints and resist flexion of interphalangeal joint
N: Lateral plantar nerve from tibial nerve (S2, S3)
1st and 2nd interossei may also have dual innervation by deep fibular nerve
Plantar interossei (4th layer) (3 muscles – unipennate)
O: Medial sides of metatarsals of 3rd to 5th toes
I: extensor hoods and bases of proximal phalanges of 3rd to 5th toes on medial side
A: Open Chain: Adduction of 3rd to 5th toes at metatarsophalangeal joint; flexion of the metatarsalphalangeal joint and extension of the interphalangeal joint
Closed Chain: resists extension of metatarsophalangeal joints and resist flexion of interphalangeal joint
N: lateral plantar nerve from tibial nerve (S2, S3)
