A8- Muscles of the leg and foot Flashcards
Name the muscles in the anterior compartment of the leg
Tibialis anterior
Extensor digitorum longus
Extensor hallucis longus
Fibularis tertius
For the anterior compartment of the leg, give its:
- Action
- Innervation
- Arterial supply
- Action: dorsiflex foot at ankle, extend the toes and invert the foot
- Deep fibular nerve
- Anterior tibial artery
Name the muscles in the lateral compartment of the leg
Fibularis longus
Fibularis brevis
For the lateral compartment of the leg, give its:
- Action
- Innervation
- Arterial supply
- Action: evert the foot
- Superficial fibular nerve
- Fibular artery
Name the muscles in the posterior compartment of the leg
Superficial: Gastrocnemius, soleus and plantaris
Deep: tibialis posterior, flexor digitorum longus, flexor hallucis longus, popliteus
For the posterior compartment of the leg, give its:
- Action
- Innervation
- Arterial supply
- Generally, they plantar flex and invert the foot, and flex the toes
- Tibial nerve
- Posterior tibial artery
What passes the medial malleolus?
Think - ‘Tom, Dick, And, Very, Nervous Harry’
From anterior to posterior:
Tibialis posterior
flexor Digitorum longus
posterior tibial Artery
posterior tibial Vein
tibial Nerve
flexor Hallucis longus
What are the margins of the popliteal fossa?
Upper: medially by semitendinosus and semimembranosus, laterally by biceps femoris
Lower: medially by medial head of gastrocnemius, laterally by lateral head of gastroc. and plantaris
Floor: capsule of knee joint, femur and tibia, popliteus
Roof: deep fascia
What does the popliteal fossa contain?
Popliteal artery
popliteal vein
Tibial nerve
Common fibular nerve
What are extrinsic vs intrinsic foot muscles? What movements are they responsible for?
Extrinsic = from compartments of the leg, eversion, inversion, plantar flexion and dorsi flexion
Intrinsic = located within the foot, for fine motor actions (i.e. moving individual digits)
How are the intrinsic muscles of the foot organised?
2 main layers - those on dorsum of the foot (facing upwards) and those in the sole of the foot.
What muscle is present on the dorsum of the foot?
Extensor digitorum brevis - gives rise to extensor hallucis brevis tendon
How many muscles are in the layers of the sole of the foot?
1st and 3rd layer = 3 muscles
2nd and 4th layer = 2 muscles and 2 tendons
What muscles are in the 1st layer (most superficial) of the sole of the foot?
‘abs flex abs’ = 2 abductors, 1 flexor:
- abductor hallucis
- abductor digiti minimi
- flexor digitorum brevis
What muscles are in the 2nd layer of the sole of the foot?
Tendons from posterior compartment:
- tendon of flexor digitorum longus
- tendon of flexor hallucis longus
Muscles:
- Quadratus plantae
- Lumbricals
What muscles are in the 3rd layer of the sole of the foot?
‘flex add flex’ = 2 flexors, 1 adductor:
- Flexor hallucis brevis
- Flexor digiti minmi brevis
- Adductor hallucis
What muscles are in the 4th layer (deepest layer) of the sole of the foot?
- Tendon of tibialis posterior
- Tendon of fibularis longus
- Dorsal interossei
- Plantar interossei
What is the action of the interossei muscles?
Dorsal interossei = DAB = Abduct toes, i.e. away from axis of 2nd toe
Plantar interossei = PAD = Adduct toes, i.e. towards axis of 2nd toe
What muscle contributes to the large plantar eminence of the sole of the foot (lateral)?
Abductor digiti minimi
Where does the tibial nerve provide sensory innervation?
Sole of foot
Where does the common fibular nerve provide sensory innervation?
lateral surface of lower leg
Where does the superficial fibular nerve provide sensory innervation?
Dorsum of the foot
What sensory nerves does the common fibular nerve branch into?
sural communicating and lateral sural cutaneous nerve
How is the sural nerve formed? Where does it provide sensation?
Sural communicating + branch of tibial nerve
Skin over posterolateral leg
What are the attachments of the fibularis longus?
Origin: lateral aspect of proximal fibula
Insertion: plantar aspect of 1st metatarsal
What are the attachments of the fibularis brevis?
Origin: lateral surface of distal half of fibula
Insertion: tuberosity of 5th metatarsal
From lateral to medial, what is the arrangement of the anterior compartment of the leg?
Fibularis tertius
Extensor Digitorum longus
Extensor Hallucis longus
Tibialis anterior
What are the attachments of tibialis anterior?
O: lateral condyle of tibia and proximal half of lateral surface of tibia
I: medial cuneiform and base of 1st metatarsal (possibly to most of foot bones)
What are the attachments of extensor digitorum longus?
O: proximal 3/4 of fibula shaft and lateral condyle of tibia
I: base of middle and distal phalanges of toes 2-5
What are the attachments of extensor hallucis longus?
O: middle 1/3 of anterior fibula
I: dorsal aspect of distal phalanx of big toe
What are the attachments of fibularis tertius?
O: distal 1/3 of anterior fibula
I: dorsal aspect of 5th metatarsal
What is an easy way to find the fibularis tertius?
Look for the most lateral tendon on the foot that doesnt go to a toe
What are the attachments of the gastrocnemius?
O: medial head= medial condyle and medial supracondylar ridge of femur, lateral head= lateral condyle and lateral supracondylar ridge
I: calcaneus via Archilles tendon
What are the attachments of plantaris?
O: lateral supracondylar line of femur
I: posterior aspect of calcaneus, medial to archilles tendon
What are the attachments of soleus?
O: posterior aspect of proximal fibula (head, neck, shaft) and tibial soleal line
I: Archilles tendon
What are the attachments of popliteus?
O: lateral condyle of femur
I: posterior surface of proximal tibia
What are the attachments of tibialis posterior?
O: posterior surface of proximal tibia and fibula
I: tuberosity of navicular and medial cuneiform
What are the attachments of flexor digitorum longus?
O: posterior surface of tibia, inferior to soleal line
I: base of distal phalanx for toes 2-5 (plantar surface)
What are the attachments of flexor hallucis longus?
O: distal 2/3 of posterior surface of fibula
I: plantar aspect of base of distal phalanx of big toe
