muscles of lower limb (below knee) Flashcards
anterior compartment
all 4 supplied by deep fibular nerve
all 4 dorsiflex ankle
extensor hallucis longus
tibialis anterior
extensor digitorum longus
fibularis tertius
extensor hallucis longus
proximal attachment : middle part of anterior surface of fibula and interosseous membrane
distal attachment : dorsal aspect of base of distal phalanx of great toe
action : extends great toe; dorsiflexes ankle
innervation : deep fibular nerve (L5, S1)
Tibialis Anterior
- *Proximal attachment** : lateral condyle and lateral surface of tibia and interosseous membrane
- *distal attachment** : medial and inferior surfaces of medial cuneiform and base of 1st metatarsal
Action : dorsiflexes ankle; inverts foot, supports arch of foot
innervation : deep fibular nerve (L4, L5)
extensor digitorum longus (EDL)
proximal attachment : lateral condyle of tibia and superior area of anterior surface of fibula and interosseous membrane
distal attachment : middle and distal phalanges of lateral four digits
action : extends lateral four digits, dorsiflexes ankle
innervation : deep fibular nerve (L5, S1)
Fibularis Teritius
Proximal attachment : inferior third of anterior surface of fibula and interosseous membrane
distal attachment : dorsal of base of 5th metatarsal
action : dorsiflexes ankle; aids in eversion of foot
innervation : deep fibular nerve (L5, S1)
lateral compartment
fibularis longus (FL)
Fibularis Brevis (FB)
both supplied by superficial fibular nerve
Everter compartment and plantar flexers
Fibularis Longus
Proximal attachment : head and superior two thirds of lateral surface of fibula
distal attachment : base of 1st metatarsal and medial cuneiform
action : evert foot; weakly plantar flex ankle. supports transverse arch of foot
innervation : superficial fibular nerve
Fibularis brevis
proximal attachment : middle part of lateral surface of fibula
distal attachment : dorsal surface of tuberosity of base of 5th metatarsal
action : evert foot; weakly plantar flex ankle
innervation : superficial fibular nerve
posterior compartment of leg
Plantarflexor compartment
Separated into superficial and deep subcompartments/muscle groups
All supplied by Tibial nerve
superficial muscle group (triceps surae)
gastrocnemius : lateral head and medial head
soleus
plantaris
Gastrocnemius
Proximal attachment :
- lateral head* : lateral aspect of lateral condyle of femur
- medial head* (bigger): popliteal surface of femur, superior to medial condyle
Distal attachment : posterior surface of calcaneus via calcaneal tendon
action : plantarflexes ankle; steadies leg on foot
innervation ; tibial nerve
Shares calcanea tendon with soleus
Soleus
Proximal attachment ; posterior aspect of head of fibula, superior quarter of posterior surface of fibula, soleal line, and medial border of tibia
Distal attachment : posterior surface of calcaneus via calcaneual tendon
action : platarflexes ankle; steadies leg on foot
innervation ; tibial nerve (S1, S2)
Shares calcanea tendon with Gastrocnemius
Plantaris
Proximal attachment : inferior end of lateral supracondylar line of femur and oblique popliteal ligament
distal attachment : posterior surface of calcaneus via calcanea tendon
action : weakly assists gastrocnemius in plantarflexing ankle; function is probably mainly proprioceptive
innervation : tibial nerve
Deep muscle group
Popliteus
Flexor Hallucis longus
Flexor digitorum longus
Tibialis posterior
Popliteus
Proximal attachment : lateral surface of lateral condyle of femur and lateral meniscus (intra-articular; within cavity of knee joint)
Distal attachment : posterior surface of tibia, superior to soleal line
action : weakly flexes knee and unlocks it by laterally rotating femur on fixed tibia, may also medially rotate tibia of unplanted limb
innervation : tibial nerve (L4, L5, S1)
Flexor hallucis longus
Proximal attachment : inferior two thirds of posterior surface of fibula and inferior part of interosseous membrane
distal attachment : base of distal phalanx of great toe (hallux)
action : flexes great toe at all joints; weakly plantarflexes ankle; supports medial longitudinal arch of foot
innervation : tibial nerve (S2, S3)
flexor digitorum longus
Proximal attachment : medial part of posterior surface of tibia inferior to soleal line and by a broad tendon to fibula
distal attachment : bases of distal phalanges of lateral four digits
action : flexes lateral four digits; plantarflexes ankle; supports for longitudinal arches of foot
innervation: tibial nerve (S2, S3)
tibialis posterior
proximal attachment : interosseous membrane, posterior surface of tibia inferior to soleal line, and posterior surface of fibula
distal attachment : primarily to tuberosity of navicular; also to cuneiforms, cuboid, and bases of 2nd-4th metatarsals
action : plantarflexes ankle; inverts foot; supports medial longitudinal arch of foot
innervation : tibial nerve (L4, L5)
calcanea tendon
-attaches gastrocnemius and soleus muscles to calcaneus
arcuate popliteal ligament
- at back of knee
- goes from lateral condyle of femur to between condyles of tibia and head of fibula
quadratus plantae
attaches to tendon of flexor digitorum longus
