Muscles Of The Lower Leg Flashcards
Gastrocnemius
Superficial posterior
Origin: Medial head- posterior surface of distal femur just superior to medial condylar
Lateral head- upper posterolateral surface of lateral femoral condyle
Insertion: via calcaneal tendon to posterior surface of calcaneus
Innervation: tibial nerve S1 S2
Function: plantarflexes foot and flexes knee
Plantaris
posterior superficial
Origin: inferior part of lateral supracondylar line of femur and oblique popliteal ligament of knee
Insertion: via calcaneal tendon to posterior surface of calcaneus
Innervation: tibial nerve S1 S2
Function: plantarflexes foot and flexes knee
Soleus
Posterior superficial
Origin: soleal line and medial border of tibia; posterior aspect of fibular head and adjacent surfaces of neck an proximal shaft; tendinous arch between tibial and fibular attachments
Insertion:via calcaneal tendon to posterior surface of calcaneus
Innervation: tibial nerve S1 S2
Function: plantarflexes the foot
Popliteus
Posterior deep
Origin: lateral femoral condyle
Insertion: posterior surface of proximal tibia
Innervation: tibial nerve L4 S1
Function: stabilises knee joint (resists lateral rotation of tibia on femur) unlocks knee joint (laterally rotates femur on fixed tibia)
Flexor hallucis longus
Posterior deep
Origin: posterior surface of fibula and adjacent interosseous membrane
Insertion: plantar surface of distal phalanx of great toe
Innervation: tibial nerve S2 S3
Function: flexes great toe
Flexor digitorum longus
Posterior deep
Origin: medial side of posterior surface of the tibia
Insertion: plantar surfaces of bases of distal phalanges of the lateral 4 toes
Innervation: tibial nerve S2 S3
Function: flexes lateral 4 toes
Tibialis posterior
Posterior deep
Origin: posterior surfaces of interosseous membrane and adjacent regions of tibia and fibula
Insertion: mainly to tuberosity of navicular and adjacent region of medial cuneiform
Innervation: tibial nerve L4 L5
Function: inversion and plantarflexion of foot, support of medial arch of foot during walking
Fibularis longus
Lateral compartment
Origin: upper lateral surface of fibula, head of fibula, occasionally lateral tibial condyle
Insertion: undersurface of lateral sides of distal end of medial cuneiform and base of metatarsal I
Innervation: superficial fibular nerve L5 S1 S2
Function: Eversion and plantarflexion of foot, supports arches of foot
Fibularis brevis
Lateral compartment
Origin: lower 2/3 of lateral surface of shaft of fibula
Insertion: lateral tubercle at base of metatarsal V
Innervation: superficial fibular nerve L5 S1 S2
Function: Eversion of foot
Tibialis anterior
Anterior compartment
Origin: lateral surface of tibia and adjacent interosseous membrane
Insertion: medial and inferior surfaces of medial cuneiform and adjacent surfaces on base of metatarsal I
Innervation: deep fibular nerve L4 L5
Function: Dorsiflexion of foot at ankle joint, inversion of foot, dynamic support of medial arch of foot
Extensor hallucis longus
anterior compartment
Origin: middle half of medial surface of fibula and adjacent surface of interosseous membrane
Insertion: dorsal surface of base of distal phalanx of great toe
Innervation: deep fibular nerve L5 S1
Function: extension of great toe and Dorsiflexion of foot
Extensor digitorum longus
Anterior compartment
Origin: proximal one half of medial surface of fibula and related surface of lateral tibial condyle
Insertion: via dorsal digital expansions into bases of distal and middle phalanges of lateral 4 toes
Innervation: deep fibular nerve L5 S1
Function: extension of lateral 4 toes and Dorsiflexion of foot
Fibularis tertius
Anterior compartment
Origin: distal part of medial surface of fibula
Insertion: dorsomedial surface of base of metatarsal V
Innervation: deep fibular nerve L5 S1
Function: Dorsiflexion and Eversion of foot
