Anatomy - The Foot & Ankle Flashcards
Talocrural joint
Large joint between distal end of tibia + fibula and superior surface of the talus
What kind of joint is the talocrural joint
Hinge joint - flexion (plantarflexion) and extension (dorsiflexion)
How is the talocrural joint a close packed joint
Talus is wider anteriorly than posteriorly so when in dorsiflexion, wider part of talus sits on tibia and fibula
When is the talocrural joint loose packed
When in plantar flexion, the more narrow part of the talus sits on tibia + fibula
Less stable - more likely to imbalance causing a flexion-inversion injury
Mortice lock
Syndesmosis blends into interosseus membrane
Interosseus membrane
Found in between tibia and fibula
Syndesmosis
Strong ligament that holds tibia and fibula together to prevent talus passing between them
Collateral ligaments in the foot and ankle
Deltoid ligaments
Anterior talofibular ligament
Posterior talofibular ligament
Calcaneo-fibular ligament
Deltoid ligament
Found medially
Triangle shaped and v strong
Originates from MM and anterior part travels to navicular and the posterior to the talus
Anterior talofibular ligament
Joins fibula to talus
Most likely ligament to be damaged
Found laterally
Calcaneo-fibular ligament
Runs from fibula to calcaneus
Found laterally
Posterior talofibular ligament
Travels from fibula to talus
Found posteriorly
Subtalar joint
Allows inversion and eversion of the ankle joint
Mid-tarsal joint
Plane joint between 2 rows of tarsal bones
Allows passive movement of pronation and supination (useful when walking on uneven ground)
Walking tripod
Calcaneous
Head of MT1
Head of MT5
Move apart in a spring fashion
How does the walking tripod improve walking and running
Reduces wear and tear by acting as a shock absorber
Arches of the foot
Medial longitudinal arch
Lateral longitudinal arch
Transverse longitudinal arch
Spring ligament
Talocalcaneonavicular ligament
Reinforces talocalcaneonavicular joint inferiorly to prevent subluxation of head of talus
Which arch does the spring ligament support
Medial longitudinal arch
Tibialis posterior
Tendon found in posterior aspect of the tibia
Passes through MM to attach to spring ligament
Which arch does tibialis posterior support
Longitudinal arches
Plantar ligaments
Short one is deep to long one
Arise from calcaneous
Attaches to short/ long flexor tendons of foot
Which arch do plantar ligaments support
Both medial and lateral longitudinal arches
Peroneus/ fibularis longus
Oblique tendon that originates from lateral aspect, passes through LM and crosses to medial side attaching to base of 1st MT
What does peroneus longus create
Transverse longitudinal arch
Plantar Aponeurosis
Layer of fascia that attaches proximally to the calcaneus and then to the heads of the MT’s
Function of Plantar Aponeurosis
Support longitudinal arches
Prevent slip on dorsal surface - tethers skin and bone, creating pockets of fat (cushioning)
Medial longitudinal arch
Between calcaneus, talus, navicular, cuneiforms and metatarsals 1-3
Highest arch therefore most effective
Lateral longitudinal arch
Between calcaneus, cuboid and metatarsals 4-5
Transverse longitudinal arch
Between cuboid, cuneiforms and metatarsal bases
Joints in the foot
Metatarsophalangeal Tarsometatarsal Subtalar Mid-tarsal Proximal interphalangeal Distal interphalangeal Interphalangeal joint of big toe
When can the syndesmosis be damaged
When excessive rotational external force is placed on calcaneous
