Part 6: Lower Leg Anterior Compartment Flashcards
Describe the cutaneous innervation of the anterior compartment
Saphenous nerve: infrapatellar branch which supplies medial side of LL to foot
Lateral cutaneous nerve of calf: Branch of CP nerve, supplies upper extensor region of LL
Superficial peroneal nerve: Supplies lower lateral surface
Which muscles for the “guy ropes” of the leg/pelivs?
Gracilis - pubis to tibia
Sartorius - Ilium to tibia
Semi-T - ischium to tibia
Note all run from pelvis to insert in tibia
What is patella ligaments insertion/
Smooth area lying obliquely on tibial tuberosity
Describe the bursa in relation to the patella
Prepatellar - superficial to patella (housemaids knee)
Superficial infrapatellar - below patellar in front of patellar ligament (clergyman’s knee)
Deep infrapatellar - between patella ligament and tibia
2 inter muscular septums pass from surface of deep fascia to fibula inclosing the peroneal compartment. What are they and how do they relate to the other compartments of the LL?
Anterior IMS: Between AIMS and tibia is extensor compartment
Posterior IMS: Between PIMS and tibia lies flexor compartment of LL
What are the muscles of the extensor comapartment?
Tibialis anterior, Extensor Hallucis longus, Extensor digitorum longus, peroneus tertius
What is the superior extensor retinaculum?
Thickening of fascia over lateral malleoulus. Provides tunnel for tendons to pass though (TA perforates it)
What is the origin, insertion, action and innervation of tibialis anterior?
O: Upper half lateral tibia and IOM
I: Inferomedial aspect medial cuneiform and base 1st MT
A: Extends and inverts foot at ankle, hold up medial longitudinal arch
N: Deep peroneal nerve
What is the origin, insertion, action and innervation of Extensor hallucis longus?
O: Middle half anterior shaft of fibula
I: Base distal phalanc great toe
A: Extend great toe, secondarily dorsiflexes ankle
N: Deep peroneal nerve
What is the origin, insertion, action and innervation of Extensor digitorum longus
O: Upper 2/3 anterior fibular, IOM and superior TF joint
I: Extensor expansions of lateral four toes
A: Extends toes secondarily dorsiflexes ankle
N: Deep peroneal nerve
What is the origin, insertion, action and innervation of peroneus tertius
O: Lower 1/3 fibula
I: Base of 5th and via extensions up dorsal shaft of 5th MC
A: Dorsiflex and evert foot
N: Deep peroneal nerve
Describe the path of deep peroneal nerve
Arises from popliteal fossa as bifurcation of common PN. Spirals around fibula neck to reach IOM. Lies between EDL and TA and supplies all 4 muscles of compartment
Describe the path of anterior tibial artery
Formed at bifurcation of popliteal artery, passes forwards above upper border of IOM. Runs down IOM and crosses lower end of tibia to become DP artery. TA lies medial throughout.
Why does superior TF joint have a synovial membrane?
In embryo fibula articulates with femur but differential growth has the fibula sink below. Movements at superior TFJ are entirely passive
Describe the inferior Tibia-fibula joint
Fibrous joint. Strongly bound together by IO tibiofibular ligaments
