What structures make up the ankle mortise?
- Deep socket
- Medial and lateral malleoli
- Distal tibia
- Trochlea of talus
What makes up the structural support of the ankle mortise?
- Lateral side - fibula, lateral malleolus
- Medial side - deltoid ligaments
What are the closed vs open packed positions of the talocrural joint?
- Closed: dorsiflexion, especially in weight bearing
- Open: plantarflexion
What are the talocrural arthrokinematics of plantar flexion and dorsiflexion?
- Plantarflexion: talus on tibia, roll and slide in opposite directions, achilles tendon on slack, anterior capsule/ligaments taut
- Dorsiflexion: talus on tibia, roll and slide in opposite directions, achilles tendon taut, anterior capsule/ligaments on slack
What ligaments are taut and what ligaments are slack in weight bearing dorsiflexion/medial rotation?
- Slack: anterior talofibular ligament, tibiotalar and tibocalcaneal fibers (deltoid ligament)
- Taut: posterior talofibular ligament, tibionavicular (deltoid ligament)
What ligaments are taut and slack in weight bearing plantarflexion/lateral rotation?
- Slack: tibionavicular fibers (deltoid ligament), posterior talofibular ligament
- Taut: anterior talofibular ligament, tibiotalar and tibiocalcaneal fibers (deltoid ligament)
What are the characteristics of the ankle joint capsule?
- Membranous capsule is thin except on medial side
- Capsule is reinforced by anterior/posterior talofibular ligaments, calcaneofibular ligament, and deltoid ligament
What are the posterior ligaments of the subtalar joint?
- Interosseous ligament
- Cervical ligament
Name the lateral ligaments of the foot/ankle and their function
- Anterior talofibular
- Posterior talofibular
- Bifurcate ligament
- Resist excessive inversion
- Limit anterior/posterior displacement of the talus on tibia
Name the medial ligaments of the foot/ankle and their function
- Deltoid ligament: tibionavicular, tibiotalar, tibiocalcaneal fibers
- Spring ligament
What is the spring ligament and why is it important?
- Plantar calcaneonavicular ligament
- Holds the head of the navicular in place
- Main supporter of medial longitudinal arch
- Excessive prolonged pressure can lead to fallen arches
What are the arches of the foot and why are they important?
- Transverse arch
- Medial and lateral longitudinal arches
- Create a dome shape to the foot (most architecturally sound form)
What are the major articulations and movements of the foot?
- Subtalar joint
- Transverse tarsal joints
- Tasrometatarsal joints
- Metatarsophalangeal joints
- Interphalangeal joints
What are the movements that occur at the subtalar joint?
- Inversion and eversion
- Allows for adaptive positioning
What are the foot motions that make up supination?
- Subtalar inversion
- Forefoot adduction
What are the foot motions that make up pronation?
- Subtalar eversion
- Forefoot abduction
What are the foot motions of the transverse tarsal joints?
- Talonavicular joint: inversion/eversion
- Calcaneocuboid: limited motion, som abduction/adduction
- Allows for adaptations necessary for ground terrain
What are the motions of the tarsometatarsal joints?
- Gliding and sliding
- Permits pivoting and side to side movements of the foot
What are the motions of the metatarsophalangeal joints?
- Flexion and extension
- Movements important in propulsion
What are the motions of the interphalangeal joints?
- Flexion and extension
- Controls push off and movement of the COM over the foot
What are the functions of the intrinsic muscles of the foot?
- Most are located on the planar surface of the foot
- 4 layers
- Span calcaneous to base of proximal phalanges
- binding rod for longitudinal arch
What are the functions of the extrinsic muscles of the foot?
- Maintain arches
- Stabilize joints
- Shock absorption
- Control toes
What are some pathologies of the foot?
- Plantar faciitis: overstretched fascia creaste microtears
- Bursitis: inflamed bursa
- Shin splints: stronger PF muscles than DF muscles
- Pes cavus: high arch, shortens foot, pressure on MT heads
- Hallux vagus: bunion due to sesamoid shift and thickened MT head
- March foot: hairline fracture across 2nd MT