bones and joints Flashcards
functions of ankle joint
Gives a stable base of support
Provides a rigid lever for push-off
Absorbs shock of body weight
Conforms the foot to irregular terrain
Important role in sensation / proprioception / balance
Allows adjustment of line of gravity in standing
Provides propulsion & restraint in walking
bones of the leg
med/lat condyle head of fibula tibial tuberosity tibia fibula fibular notch med/lat malleolus
tibia framework
the weight bearing bone of the lower leg
larger of the 2 bones
proximally forms part of the knee joint
distally forms most of the ankle joint
fibula framework
on the lateral side of the leg; smaller of the 2 bones
proximally, articulates with the lateral condyle of the tibia (superior tibio-fibular joint)
distally, articulates with the tibia (inferior tibio-fibular joint) and the talus (ankle joint)
distal tibia
The distal end of the tibia is shaped like a rectangular box with the bony protuberance the MEDIAL MALLEOLUS
The inferior surface of the tibia articulates with the TALUS to form part of the ankle joint.
The inferior surface continues medially as the malleolar articular surface
On its lateral surface is a deep groove where it articulates with the fibula (Inferior tibio-fibular joint)
distal fibula
The bony protuberance on the lateral side of the fibula forms the lateral malleolus.
the medial surface of the lateral malleolus bears a facet for articulation with the talus
fibula notch at the distal end of the tibia
Distal tibia and fibula articulate with the talus of the foot at the ankle joint
Superior Tibio-Fibular Joint
Classification:
Synovial plane joint.
Artic. Surfaces
Head of fibula, tibial lateral condyle, capsule attached around joint margins.
Ligts
Ant. and post. ligts of the fibular head.
Movements
Small rotational movements during ankle DF/PF +/- gliding.
Interosseous Membrane
A tough, fibrous sheet of connective tissue
It spans the distance between the borders of the tibia and fibula
Most fibres descend obliquely from tibia to fibula
Provides attachment for muscles
Separates anterior & posterior compartments
Inferior Tibio-Fibular Joint
fibrous syndesmosis
Medial aspect of fibula and fibular notch on lateral aspect of tibia
Anterior inferior, Posterior inferior & Transverse tibio-fibular ligaments
Slight rotation of the fibula on the tibia during ankle dorsiflexion
Ankle fractures involving excessive rotatory stresses rupture the interosseous ligament and membrane
bones of the foot
Tarsal bones Talus Calcaneus Cuboid Navicular Cuneiforms medial intermediate lateral Metatarsals 5 metatarsals Phalanges 14 phalanges
talus
Situated above the calcaneus Head and neck directed forwards & medially Body is wedge shaped, lies between the malleoli Superior surface of the body is wider anteriorly, creating the stable locking mechanism in dorsiflexion Situated above the calcaneus Head and neck directed forwards & medially Body is wedge shaped, lies between the malleoli Superior surface of the body is wider anteriorly, creating the stable locking mechanism in dorsiflexion
The Ankle Joint
A synovial hinge joint
A Mortise & Tenon type of joint
Covered in hyaline cartilage
Enclosed by joint capsule, lined with synovial membrane
Between the distal end of the tibia & fibula, and the talus of the foot
Allows dorsiflexion and plantarflexion
The Calcaneus (Superior Aspect)
Has 6 surfaces: Anterior Posterior Inferior Lateral Medial Superior
Calcaneus (Medial Aspect)
Largest of the tarsal bones
Sustentaculum tali, medial shelf to support medial head of talus
Posterior surface, roughened for attachment of tendocalcaneus
Subtalar Joint
Distal to the ankle joint
Where talus articulates with calcaneus
Movements of Inversion and Eversion
A plane (modified Saddle) synovial joint
Surrounded by a weak articular capsule
Capsule supported medially, laterally and posteriorly by talocalcanean ligaments
Joint stabilised by interosseous talocalcanean ligament
