The foot and ankle region Flashcards
Function of the ankle joint
gives a stable base of support, provides a rigid level 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 and restraint walking
bones of lower leg
tibia- condyles and tuberosity, fibula
distal tibia and fibula
fibula notch- inferior aspect of tibia that articulates with fibula, medial and lateral malleolus
Framework of lower leg- tibia
the weight bearing bone of the lower leg, larger of 2 bones, proximally forms knee joint, distally forms the ankle joint
Framework of lower leg- fibula
on the lateral side of the leg, smaller of the 2 bones, proximally articulates with the lateral condyle of the tibia (superior tibiofibular joint), distally articulates with the tibia (inferior tibiofibular 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
what does the inferior tibia articulates with
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
distal fibula
the bony protuberance on the lateral side forms the lateral malleolus, the fibula notch is at the distal end of the tibia, the distal fibula is convex it is received to the tibia in a concave facet on the tibia (fibula notch), this is syndesmosis
articulations at the distal fibula
the medial surface of the lateral malleolus bears a facet for articulation with the talus, distal tibia and fibula articulate with the talus of the foot and ankle joint
Superior tibiofibular joint- classification and articular surface
synovial plane joint,
articular surface- head of fibula, tibial lateral condyle, capsule attached around the joint margin
Superior tibiofibular joint- ligaments and movements
ligaments- anterior and posterior ligaments of fibula head
movements- small rotational movements during ankle DF/PF (gliding)
what is the interosseous membrane
a tough, fibrous sheet of connective tissue, it span the distance between the borders of the tibia and fibula, most fibres decent obliquely from tibia to fibula
role of interosseous membrane
provides attachment for muscles, separates anterior and posterior compartments
inferior tibiofibular joint- surfaces
medial aspect of fibula and fibula notch on lateral aspect of tibia,
inferior tibiofibular joint- classification and ligaments
it is a fibrous syndesmosis, Anterior inferior, posterior inferior and transverse tibiofibular ligaments
movements of inferior T-F joint
slight rotation of the fibula on the tibia during ankle dorsiflexion,
maisonneuve fracture
ankle fracture involving excessive rotatory stresses rupture the interosseous ligament and membrane (maisonneuve fracture)
bones of the foot
tarsal bones, metatarsals (5), phalanges (14)
tarsal bones
talus, calcaneus, cuboid, navicular, cuneiform (medial, lateral, intermediate)
the talus
situated above the calcaneus, head and neck directed forwards and medially, body is wedged shape- lines between malleoli, superior surface of the body is wide anteriorly, creating the stable locking mechanisms in dorsiflexion
3 articular facets of talus
the body of the talus has 3 articular facets which articulate with the tibia and malleoli (superior facet- trochlea, medial facet, lateral facet)
shape of the talus
it is convex from anterior to posterior and concave from side to side (pulley shape). its wedge shape prevents posterior displacement of the foot (of the talus in the mortise) during sudden jumps and stops
ankle joint talocrural joint- classification and articular surfaces
a synovial hinge joints, 3 surfaces- distal fibula projects more distally than the malleolus, the distal aspect of tibia, medial articulation with the medial malleolus, and the talus
ankle joint talocrural joint- joint structures
a mortise and tenon type of joint, covered in hyaline cartilage, enclosed by joint capsule, lined with synovial membrane
ankle joint talocrural joint- position
between the distal end of the tibia and fibula, and the talus of the foot
ankle joint talocrural joint- movements
PF and DF
6 surfaces of the calcaneus (superior aspect)
anterior, posterior- gastrocnemius and soleus attach via achilles tendon to middle facet , inferior, lateral, medial (has a bony shelf called sustentaculum tali), superior
articular of talus
3 articular on inferior surface of talus- receiving facets on superior facing of calcaneus
the calcaneus medial aspect
largest of the tarsal bones, sustentaculum tali- medial shelf to support medial head of talus, posterior surface roughened for attachment of tendocalceneus
subtalar joint line medial
sustentaculum tali- medial aspect occupied by, this is where the medial line is
subtalar joint line lateral
deep to lateral malleolus and distal fibula, lateral articular surface of talus to the calcaneus, in line with distal tib of fibula
subtalar joint- position
distal to the ankle joint, where talus articulates with the calcaneus
subtalar joint- movements
inversion and eversion (add and abduction)
subtalar joint- classification
a plane (modified saddle) synovial joint
subtalar joint- joint structures
surrounded by a weak articular capsule, capsule supported medially, laterally and posteriorly to talocalcaneal ligaments, joint stabilised by interosseous tolocanal
navicular
anterior to head of talus and medial malleolus, prominent medial tuberosity, concave posterior surface articulates with head of talus
articular facets of navicular
3 articular facets for articulation with the 3 cuneiform, concave facet for articulation with the convex talus
Cuboid articulations- posterior
with calcaneus, calcaneocuboid joint
Cuboid articulations- medial
with lateral cuneiform, cuneocuboid joint
Cuboid articulations- anterior
4th and 5th metatarsal, tarsometatarsal joint
midtarsal joint- classification
synovial ball and socket joint, S shaped joint
midtarsal joint- medial and lateral
talocalcaneonavicular (medial aspect) and calcaneocuboid (lateral aspect), (compound joint )
midtarsal joint- movements
combines with the subtalar joint eversion and inversion to produce pronation- abduction (up and out) and supination (down and in)-adduction
midtarsal joint- shape
convex anteriorly, double back in itself, becomes concave facing anteriorly joint between calcaneus and cuboid
bones of the tarsus cuneiforms- articulations
articular with navicular, articulate with each other (neighbors)
bones of the tarsus cuneiforms- articulations
medial- articulates with MT1, intermediate- articulates with MT 2, lateral- articulates with MT 2, adn with cuboid
bones of the tarsus cuneiforms- classification
all joints are synovial plane joints
cuneo- navicular joints
synovial plane joint- gliding and sliding, bonded together by tight fibrous capsule and ligaments
inter-cuneiform and calcaneocuboid joints
synovial plane joints
metatarsals
1-5, 5 long bones, tuberosity on the base of the 5th MT
Metatarsals- 1-3
bases MT’s 1,2 and 3 articulates with the 3 cuneiforms
Metatarsals 4-5
bases articulate with the cuboid
what do MT’s articulate with
with each other at plane synovial joint
first mt
2 sesamoid bones embedded within tendon of: flexor hallucis brevis (flex greater toe), this is in the first MT
Phalanges
long bones, greater roe has proximal and distal phalanges, they have head, neck, shafts and bases.
Lateral 4 toes- proximal, middle, and distal phalanges
tarsometatarsal joint
a synovial plain joint
metatarsal phalangeal joint
a synovial ellipsoid
proximal and distal interphalangeal joint
synovial hinge joint- flexion / extension, great toe only has one interphalangeal joint, supported by collateral ligaments on either side of the joint
