THE ANKLE LIGAMENTS (N494, N495)
Lateral Collateral Ligament
Anterior and Posterior Talofibular Ligaments (Talus <====> Fibula)
Calcaneofibular Ligament (Calcaneous <====> Fibula) -- it crosses the Subtalar joint to help support it.
Often happens by an inversion injury, where the foot is inverted, placing too much pressure on the Anterior Talofibular Ligament, which you can
sometimes see ball up.
Deltoid (Medial) Ligament: Group of four ligaments composing the medial ankle. Various tibiotarsal ligaments.
Transverse Tarsal Joint / Ligament: aka Chopart's Joint. Allows for pronation and supination of the foot. A common point of amputation.
LISFRANC'S JOINT: TARSOMETATARSAL JOINT -- very important joint. Injuries to this area are common.
Fractures of the 2nd metatarsal are common, because the 2nd metatarsal is less mobile because it is inset from the 2nd cuneiform.
Long Planter Ligament: Helps maintain the arch of the foot.
Calcaneonavicular (Spring) Ligament: Helps maintain
the arch of the foot.
PLANTAR APONEUROSIS: Similar to the palmar aponeurosis,
it keeps the skin on the sole of your foot immobile, so you can
walk on it.
Origin from Calcaneous Tuberosity.
Inserts on much of the skin of the sole of the
PERONEAL RETINACULUM: Lateral side of foot
Contents: Peroneus Longus and Peroneus Brevis tendons.
Continuous with the inferior part of the extensor retinaculum
EXTENSOR RETINACULUM: Along dorsum of foot
It is Y-Shaped, dividing into a superior and inferior portion on the lateral side of the foot. The stem of the Y is on the medial side and is continuous with
the Peroneal Retinaculum.
Extensor Digitorum Longus tendon
Extensor Hallucis Longus tendon
Peroneus Tertius tendon
Dorsalis Pedis Artery and Deep Peroneal Nerve pass underneath.
FLEXOR RETINACULUM: On the medial side of the foot, from the medial malleolus to the calcaneous. All of the flexor tendons pass through it as they
wrap around to the plantar aspect of the foot.
Contents: Tom Dick ANd Harry
Tibialis Posterior tendon
Flexor Digitorum Longus tendon
Posterior Tibial Artery
Posterior Tibial Nerve
Flexor Hallucis Longus tendon
TARSAL TUNNEL SYNDROME: Similar to Carpal Tunnel
syndrome, compression of the tibial nerve under the flexor retinaculum.
BONES OF THE FOOT (N492, N493):
Calcaneous: The heel. The inferior-most aspect of the foot.
Made primarily of cancellous bone
Has three articular surfaces that articulate with the Talus at the Subtalar joint.
Posterior Articular Surface
Middle Articular Surface
Anterior Articular Surface
Talus: The ankle-region, which articulates with the Tibia.
Articulates with the Tibia, the Fibula, and the Navicular bone.
There are no blood vessels going to the Talus. There are no muscle attachments to the Talus.
A lot of the Talus blood supply comes from the Sinus Tarsi.
Has three facets that articulate with the Calcaneous
Tarsal Bones: The analog to the carpal bones in the wrist:
Cuboid Bone: Most lateral, near the 5th digit
Navicular Bone: Most medial and proximal, articulating with the Talus and Calcaneous.
Most prominent of the Tarsal bones.
It has a palpable Navicular Tuberosity.
Lateral, Intermediate, Medial Cuneiform Bones: Most distal and on the lateral side, articulating with the metatarsals.
Proximal, Middle, Distal Phalanges
ARCHES OF THE FOOT (N495, N496):
Medial Longitudinal Arch: Talus is primary connection here.
Lateral Longitudinal Arch:
Transverse Arch: The Peroneus Longus Tendon helps support the Transverse arch of the foot (on the lateral side of the foot).
What keeps the foot arched?
Shape of the bones
Some muscular support
Three Plantar Ligaments help to maintain the Longitudinal Arch:
Calcaneonavicular (Spring) Ligament: Connect navicular bone to the Calcaneus.
Long and Short Plantar Ligaments: Along bottom of foot, help to maintain its arch.
Muscles that help the arch: Flexor Hallucis Longus Tendon connects from the heel to the big toe, holding the two ends of the Medial Arch together.
The longitudinal arch is lost in some flat-foot
SUBTALAR JOINT: The joint between the Talus and Calcaneus.
This joint helps you walk on unlevel ground. It accommodates with eversion and inversion of the hindfoot.
Subtalar Arthritis would prevent a person from
being able to walk on unlevel ground easily -- no eversion and
inversion of hindfoot.
QUADRATUS PLANTAR MUSCLE (2nd layer): CLAW-TOE Deformity results from scarring of this muscle. The Flexor Digitorum longus tendons are just
superficial to this muscle, and they will contract
with scarring of this muscle.
This is a common symptom of a compartment syndrome
in this compartment in the foot.
Master's Knot of Henry (N497): The crossing of the
Flexor Digitorum Longus and Flexor Hallucis Longus tendons, on
the medial side of the foot.
The two run together down the medial leg, behind
the medial malleolus. After they pass the medial malleolus, they
BUNION: Over-pull and contraction of the Adductor
Hallucis (3rd layer) Muscle.'
First toe bends in medially (in valgus)
In surgery, bunions are often fixed by releasing
the muscle in the first web-space.
ARTERIES OF THE FOOT
POSTERIOR TIBIAL ARTERY: Follows the posterior tibial nerve, to supply the plantar aspect of the foot
Medial Plantar Artery
Lateral Plantar Artery
PLANTAR ARCH: Is formed by the medial and lateral plantar arteries.
Perforating Branches are sent up between first and second metatarsals, to provide anastomosis between posterior tibial and dorsalis pedis arteries.
If one of the above arteries is cut off, therefore, you can still get blood supply to the foot.
ANTERIOR TIBIAL ARTERY: Turns into the Dorsalis Pedis
Dorsalis Pedis Artery -- supplies the dorsum of the foot. It passes underneath the extensor retinaculum.
This is a good place to feel for pulses, as the artery is very superficial.
Gives off an Arcuate Artery which forms a Dorsal Superficial Arch and in turn gives off Dorsal Metatarsal Arteries.
PERONEAL ARTERY: Normally small, unless one
of the above is absent. It normally peters out on top of the calcaneous.
NERVES OF THE FOOT:
TIBIAL NERVE -- Divides into
Medial and Lateral Plantar Nerves -- the primary motor innervation of the foot.
DEEP PERONEAL NERVE
SUPERFICIAL PERONEAL NERVE
COMPARTMENTS OF THE FOOT:
CLINICAL -- CALCANEOUS FRACTURES are common with
The calcaneous is largely cancellous rather than cortical bone, which makes it subject to breaking.
Common mode of action: The Talus gets driven inferiorly into the calcaneous.
Boehler's Angle = the angle between the calcaneous and talus. It becomes flattened.
Fractures are most common through the Posterior Facet of the Talus.
If you don't operate you can lose the height
of the foot, making it so shoes don't fit very well!
LISFRANC (TARSOMETATARSAL) JOINT FRACTURES -- most
commonly occur at the 2nd metatarsal bone, because it is inset
next to the 2nd cuneiform.
This is the location of the transverse arch of the foot.
You can get pain in this fracture because the superficial peroneal nerve is directly dorsal to the joint, too.
Chronic pain and arthritis is common with this,
and the joint must be fixated to restore anatomical normality.
STRESS FRACTURE: A fracture that doesn't result from trauma, but results from fatigue in a bone. The fracture is usually small and/or diffuse.