Anterior Leg, dorsum of foot and lateral compartment Flashcards
what are the 4 muscles of the anterior leg
- tibialis anterior
- extensor hallucis longus
- extensor digitorum longus
- peroneus tertius
tibialis anterior:
origin
insertion
action
function
innervation
pathology
- origin: lateral shaft of tibia, IoM, intermusculare septa
- insertion: under extensor retinaculum to medial cuneiform and base of 1st metatarsal
- action: AJ dorsiflexion, supination (STJ and long axis of MTJ)
- function: decellerates pronation and plantar flexion from HC, toe clearance suring swing phase
- innervation: deep peroneal nerve
- pathology: weak: foot drop, excessive pronation
contracture: supinated foot
extensor hallucis longus
origin
insertion
innervation
action
- origin: middle half of medial surface of fibula, IoM
- insertion: dorsal surface of base of distal phalanx of the hallux
- innervation: deep peroneal nerve
- action: AJ dorsiflexion, extends/stabilises hallux phalanges
extensor digitorum longus
origin
insertion
innervation
action
- origin: lateral tibial condyle, uper medial fibula, IoM
- insertion: divides into 4 slips, base of distal phalanx of the lesser 4 toes, and base of intermediate phalanx
contributes to extensor hood - innervation: deep peroneal nerve
- action: AJ dorsiflexion, extends lesser toe phalanges
where do the long and short flexors/extensors insert
- long: distal phalanx - motion at DIPJ
- short: intermediate phalanx - motion at PIPJ
peroneus tertius:
closely related to which tendon
origin
insertion
innervation
action
- closely related to which tendon: EDL
- origin: distal 1/4 of fibula and IoM
- insertion: dorsal surface of base of 5th MT
- innervation: deep peroneal nerve
- action: foot eversion, AJ dorsiflexion, weak foot pronator
what is the arterial supply to the anterior leg
- anterior tibial artery
- smaller branches of the popliteal artery
- becomes dorsalis pedis in front of the ankle joint
where is the retinacular of the anterior leg
- superior extensor retinaculum:
anterior border of fibular to anterior border of tibia
continuous with deep fascia - inferior extensor retinaculum
y-shaped band
calcaneous to tibia and plantar aponeurosis
flexor retinacula - lacinate ligament
medial malleolus to medial tuberosity of calcaneous
protects and supports medial tendons, vessesl, nerve
peroneal retinacula
- superior peroneal retinaculum
lateral malleolus to lateral calcaneous - inferior retinacula
continuous with inferior extensor retinaculum
peroneal tubercle to plantar aponeurosis
what is the nerve of the anterior leg
deep peroneal
what is a dermatome
the area of skin supplied by a single spinal nerve, and therefore a single nerve segment
what nerves supply the dorsum of the foot (4)
- superficial peroneal nerve - divides into
medial and lateral dorsum - deep peroneal nerve
- saphenous nerve
- sural nerve
where is the dorsal venous arch, where does it drain, and what is its relevance
- lies in the cutaneous tissue over the MT heads
- drains into the great saphenous vein medially and the small saphenous vein laterally
- drains a huge amount of blood from the foot via digital veins and communicating vens from the sole of the foot
what is the route of the dorsalis pedis artery
- passes deep into the sole of the foot between the 1st and 2nd MT
- joins the lateral plantar artery (plantar arch)
- superficial
- branches into lateral tarsal artery, arcuate artery, 1st dorsal MT artery
extensor digitorum brevis:
origin
insertion
innervation
action
- origin: anterior dorsal calcaneous and inferior extensor retinaculum
- insertion: splits into 4 tendons
- innervation: lateral branch of deep peroneal
- action: ext of hallux MTPJ, extension of 2,3,4 MTPJ and IPJs
what are the arteries of the dorsal foot
- anterior tibial artery
smaller branch of popliteal artery - dorsalis pedis
- arcuate
- dorsal digital
what are the muscles of the lateral leg
peroneus longus and brevis
what is the blood supply of the lateral leg
branches of the peroneal artery
which nerve innervates the lateral leg
superficial peroneal nerve
peroneus longus:
origin
insertion
innervation
action
- origin: upper 2/3rd of lateral fibular and intermuscular septa
- insertion: under cuboid to base of 1st MT and medial cuneiform
- innervation: superficial peroneal nerve
- action: everts the foot, foot flexor, stabilisdes 1st ray and forefoot
peroneus brevis:
origin
insertion
innervation
action
- origin: lower 2/3rds of lateral fibular and intermuscular septa
- insertion: base 5th MTJ
- innervation: superficial peroneal nerve
- action: everts foot about STJ and oblique axis of MTJ
