muscles of lower limb (below knee)

Question 1

anterior compartment

Answer 1

all 4 supplied by deep fibular nerve

all 4 dorsiflex ankle

extensor hallucis longus

tibialis anterior

extensor digitorum longus

fibularis tertius

Question 2

Answer 2

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)

Question 3

Answer 3

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)

Question 4

Answer 4

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)

Question 5

Answer 5

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)

Question 6

lateral compartment

Answer 6

fibularis longus (FL)

Fibularis Brevis (FB)

both supplied by superficial fibular nerve

Everter compartment and plantar flexers

Question 7

Answer 7

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

Question 8

Answer 8

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

Question 9

posterior compartment of leg

Answer 9

Plantarflexor compartment

Separated into superficial and deep subcompartments/muscle groups

All supplied by Tibial nerve

Question 10

superficial muscle group (triceps surae)

Answer 10

gastrocnemius : lateral head and medial head

soleus

plantaris

Question 11

Answer 11

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

Question 12

Answer 12

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

Question 13

Answer 13

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

Question 14

Deep muscle group

Answer 14

Popliteus

Flexor Hallucis longus

Flexor digitorum longus

Tibialis posterior

Question 15

Answer 15

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)

Question 16

Answer 16

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)

Question 17

Answer 17

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)

Question 18

Answer 18

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)

Question 19

calcanea tendon

Answer 19

-attaches gastrocnemius and soleus muscles to calcaneus

Question 20

arcuate popliteal ligament

Answer 20

• at back of knee
• goes from lateral condyle of femur to between condyles of tibia and head of fibula

Question 21

quadratus plantae

Answer 21

attaches to tendon of flexor digitorum longus