muscles of the leg Flashcards
Compartments of the leg + functions of their muscles
Anterior — extensors
Posterior — flexors
Lateral — eversors
The muscles in the anterior compartment of the leg are innervated by the…
Deep fibular nerve
Muscles of the anterior compartment of the leg
Tibialis anterior, extensor digitorum longus, extensor hallucis longus + fibularis tertius
Site of origin, trajectory + insertion of tibialis anterior
Origin: anterolateral portion of the proximal tibia
Trajectory: inferomedial, passes in front of the medial malleolus
Insertion: inferomedial portion of the medial cuneiform bone
Site of origin + insertion of extensor digitorum longus
Origin: anterior portion of the fibula
Insertion: phalanges of the 2. to 5. toes
Function of tibialis anterior
Dorsiflexion (extension of the ankle)
Function of extensor digitorum longus
Extension of the 2. to 5. toes
Site of origin + insertion of extensor hallucis longus
Origin: anterior surface of the fibula (more distally than EDL)
Trajectory: moves inferomedially
Insertion: phalanx of the 1. toe
Function of extensor hallucis longus
Extension of the big toe
Site of origin + insertion of fibularis tertius
Origin: anterior portion of the fibula (partially separated from the EDL)
Trajectory: moves inferolaterally, towards the 5th toe
Insertion: base of the 5th metatarsal
The fibularis longus muscle originates in…
The proximolateral portion of the fibula
Trajectory of the fibularis longus
Moves down towards the lateral maleolus, passes through the superior + inferior fibular retinaculi, inserts into an inferior groove in the cuboid bone + crosses over to the first metatarsal
Site of insertion of the fibularis longus
Base of the 1. metatarsal
The muscles in the lateral compartment of the leg are innervated by the…
Superficial fibular nerve
The fibularis brevis originates in…
The lateral portion of the fibula, but lore distallly than the FL does
Trajectory of the fibularis brevis
It moves down towards the lateral maleolus, passes underneath it + through the superior + inferior fibular retinaculi, then moves laterally and forwards towards the tubercle of the 5. metatarsal
The fibularis longus inserts into
a) the base of the 1. metatarsal
b) the proximal phalanx of the 5. toe
c) the lateral cuneiform bone
a)
Muscles that make up the calcaneal (Achilles) tendon
Gastrocnemius + soleus
Site of origin of the 2 heads of the gastrocnemius
Medial head: medial posterior portion of the distal femur
Lateral head: lateral posterior portion of the distal femur
Nerve that innervates the muscles in the posterior compartment of the leg
Tibial nerve
Site of origin of the soleus muscle
Posterior portion of the proximal tibia (in the soleal line) + posterior portion of the fibula
What is the plantaris tendon
Long tendon that originates from the plantaris muscle, which originates in the posterior portion of the proximal tibia + distal femur & runs medially to the head of the medial gastrocnemius
The popliteus muscle originates in…
The medial portion of the posterior proximal tibia
Muscle that has an oblique orientation + moves superiolaterally
Popliteus
Site of insertion of the popliteus muscle
Lateral portion of lateral epicondyle (femur)
Which muscle of the lateral compartment of the leg passes closer to the lateral maleolus
Fibularis brevis
The flexor digitorum longus originates in…
The posteromedial part of the proximal tibia
Trajectory + insertion of the FDL
Moves down to the medial malleolus + inserts into the distal phalanges of 2. to 5. toes
Nerve that innervates the muscles in the posterior compartment of the leg
Tibial nerve
The FHL originates in…
Posterior portion of the fibula
Trajectory of the FHL
Moves down, passes through the groove between the 2 tubercles of the talus (posterior part) + the sustentaculum tali until it reaches the distal phalanx of the big toe
Insertion of the FHL
Base of the distal phalanx of the big toe
The tibialis posterior originates…
In the interosseous membrane
Muscle that passes anteriorly to the FDL in the medial maleolus
Tibialis posterior
Insertion of the tibialis posterior
Navicular
The tibialis posterior allows for…
Inversion + plantar flexion
Which muscle of the posterior compartment of the leg originates in 2 bones + creates a tendinous arch?
The soleus
Which structures pass through the tendinous arch formed by the soleus?
Popliteal vein + artery, tibial nerve
