13 - Anterior Lateral Leg and Foot and LL Joints Flashcards
bones of the foot
7 tarsal bones, 5 metatarsal bones and 14 phalanges.
hindfoot
calcaneus and talus
midfoot
cuboid, navicular and 3 cuneiforms
forefoot
5 metatarsals and 14 phalanges
muscles of the lateral compartment of the leg
fibularis brevis and longus
actions of the lateral compartment of the leg
evert and plantarflex
innervation of the lateral compartment of the leg
superficial fibular nerve
blood supply of the lateral compartment of the leg
perforating branches of the fibular a
extensor expansions
The extensor tendons pass onto the dorsal aspects of the digits and expand over the phalanges to form complex dorsal digital expansions.
Each extensor expansion has a proximal extensor hood
extensor hood
part of extensor expansion
proximal part
triangular in shape and wraps around the MP joints to attach to ligaments in the sole of the foot
Apex expands into 3 bands: central (attaches to middle phalanges) and two lateral (insert on distal phalanges
where do many intrinsic muscles of the sole of the foot insert
lateral bands of the extensor expansion
allows forces to be distributed over the dorsum of the entire digit
where does anterior tibial artery change its name and to what
changes to dorsalis pedis artery after it passes between malleoli and enters the dorsum of the foot
where is the pulse of the dorsalis pedis felt
dorsum of the foot as the artery passes over the tarsal bones between the tendon of extensor hallucis longus and the 1st tendon of extensor digitorum longus
OVEN FELT TO TEST FOR PERIPHERAL VASCULAR DISEASE
what does dorsalis pedis artery split into and therefore end
divides into deep plantar and 1st dorsal metatarsal arteries
common fibular nerve
L4-S2
terminates by dividing into the superficial and deep fibular nerves just after it wraps around the neck of the fibula. Due to it’s superficial location and proximity to the fibular neck, it is easily injured. Fractures of the proximal fibula may sever this nerve resulting in paralysis of all the muscles in the anterior and lateral compartments of the leg (foot drop) and loss of cutaneous innervation to the lateral aspect of the leg and dorsum of the foot.
superficial fascia of the foot
- has fibrous septa that act to
- divide it into fat-filled compartments creating shock-absorbing pads o’ fat.
- Anchor the skin to the underlying deep fascia in order to improve the ‘grip’ of the sole
plantar fascia
deep fascia on the sole of the foot which helps hold the foot together, protects the plantar surface of the foot and helps support the longitudinal arches of the foot.
plantar aponeurosis
- central thickening of the plantar fascia
- longitudinally arranged bands go from the calcaneal tuberosity to the digital sheaths and proximal phalanges
- converts foot into solid lever for gait cycle
intermuscular septa of mid and forefoot
- two of them
- extend into the mid- and fore-foot from the plantar aponeurosis
- divide foot into medial, central and lateral compartments
- interosseous compartment is located between metatarsals
intrinsic muscle layers in the sole of the foot and function
- 4 groups
- resist forces that flatten longitudinal arch
- stabilise foot for propulsion by maintaining the transverse arches
- produce minor movements of inversion/ eversion to maneuver on unstable ground
- maintain balance
blood supply of the sole of the foot
branches of the posterior tibial and dorsalis pedis arteries.
bifurcation of posterior tibial a.
- medial and lateral plantar aa. as it passes through the tarsal tunnel
- travel between 1st and 2nd muscle layers of the foot
lateral plantar artery anastomoses
- anastamoses with deep plantar artery (branch of dorsalis pedis a.
- this anastomosis forms deep plantar arterial arch which traverses sole of the foot between 3rd and 4th muscle layers at level of matatarsal bases
innervation of sole of the foot
-tibial nerve, medial and lateral plantar
nerves, as well as the sural & saphenous nerves.
-medial plantar nerve innervates four intrinsic muscles of the foot
-remaining intrinsic muscles of the foot are all innervated by the lateral plantar nerve.
between which muscle layers do the lateral plantar artery and nerve run
- 1st and 2nd
- joins with deep plantar a. to form plantar arch
between which muscle layers does plantar arch run
-3rd and 4th