Joint Biomechanics - Ankle and Foot Flashcards
Stable Foot
- Sufficiently support the weight-bearing force from the body.
- Absorb the shock from landing on the ground below.
- Propel the body through space by pushing off the ground.
Generally a factor of dorsiflexion/plantarflexion of the foot at the talocrural joint.
Flexible Foot
- Adapt to the uneven ground surfaces.
Generally a factor of eversion/inversion of the foot at the subtalar joint.
Talocrural Joint
Between trochlear surface of talus (convex) and the distal tibia and fibula (concave).
Synovial hinge joint - Lock and key.
- Mortise: tibia and fibula (lock)
- Tenon: talus (key)
Motion of the Talocrural Joint
Usually combined with subtalar and midtalar joint motion.
- Plantarflexion is usually associated with adduction and inversion.
- Dorsiflexion is usually associated with abduction and eversion
Planes and ROM of the Talocrural Joint
Plantarflexion: Sagittal plane, transversal axis, 50° ROM.
Dorsiflexion: Sagittal plane, transversal axis, 20° ROM (limited due to tension in gastrocnemius).
Talocrural Joint - Position of Talus Regarding Movement
Dorsiflexion: Broader anterior part of trochlear surface of talus is forced between the narrower posterior part of tibiofibular mortise (makes it stiffer, less ROM).
Plantarflexion: Narrower posterior part of the trochlea of the talus moves forward into the broader part of the tibiofibular mortise.
Arthrokinematics of the Talocrural Joint in OKC
Plantarflexion: Convex talus glides on concave mortise (roll and slide in opposite directions), Posterior-anterior slide.
Dorsiflexion: Convex talus glides on concave mortise (roll and slide in opposite directions), Anterior-posterior slide.
Talocrural Joint - Lateral Ligaments
Between the talus and the distal tibiofibular joint. Prevent inversion. Three major ligaments: - Anterior talofibular ligament - Posterior talofibular ligament - Calcaneofibular ligament
Anterior Talofibular Ligament
Origin: Lateral malleolus
Insertion: Lateral side of talus
Posterior Talofibular Ligament
Origin: Lateral malleolus
Insertion: Posterior side of talus
Calcaneofibular Ligament
Origin: Lateral malleolus
Insertion: Calcaneus
Talocrural Joint - Medial Ligaments
Between the talus and the distal tibiofibular joint
Prevents eversion.
Deltoid ligament is a group of 4 ligaments:
- Posterior tibiotalar ligament
- Anterior tibiotalar ligament
- Tibiocalcaneal ligament
- Tibionavicular ligament
Posterior Tibiotalar Ligament
Origin: Medial malleolus
Insertion: Posterior side of talus
Anterior Tibiotalar Ligament
Origin: Medial malleolus
Insertion: Anterior side of talus
Tibiocalcaneal Ligament
Origin: Medial malleolus
Insertion: Calcaneus
Tibionavicular Ligament
Origin: Medial malleolus
Insertion: Navicular
Which ligaments control abduction of the talus?
Tibiocalcaneal ligament
Tibionavicular ligament
Which ligament controls adduction of the talus?
Calcaneofibular ligament
Which ligaments control plantarflexion?
Anterior tibiotalar ligament
Anterior talofibular ligament