Ch20: Ankle Joint and Foot Flashcards
The leg (the portion of the lower extremity extending from the knee to the ankle) consists of the…
Tibia and Fibula.
What keeps the two bones together and provides a greater surface area for muscle attachment?
A strong interosseous membrane
Leg bones and interosseous membrane (anterior view).
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The Tibia
The larger of the two bones, is the only true weight-bearing bone of the leg. Triangular in shape, the tibia’s apex (crest) is located anteriorly.
The Fibula
The long, thin fibula is set back in line with the posterior surface of the tibia. Lateral to the tibia, the fibula forms a channel, with the interosseous membrane as the floor; this permits attachment of several muscles without distorting the shape of the leg.
Medial Condyle (Tibia)
Proximal medial end
Lateral Condyle (Tibia)
Proximal lateral end
Crest (Tibia)
Anterior and most prominent of the three borders
Right leg (lateral view). Note the posterior position of the fibula.
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Medial Malleolus (Tibia)
Enlarged distal medial surface
Head (Fibula)
Enlarged proximal end
Lateral Malleolus (Fibula)
Enlarged distal end
The bones of the foot include the…
Tarsals, metatarsals, and phalanges.
Calcaneus (Tarsal Bones)
Largest and most posterior tarsal bone
Calcaneal Tuberosity (Tarsal Bones)
Projection on the posterior inferior surface of the calcaneus
Calcaneal Tuberosity (Tarsal Bones)
Projection on the posterior inferior surface of the calcaneus
Sustentaculum Tali (Tarsal Bones)
Medial superior part projecting out from the rest of the calcaneus, supporting the medial side of the talus. Three tendons loop around this projection, changing directions from the posterior leg to the plantar foot.
Talus (Tarsal Bones)
Sitting on the calcaneus, it is the second largest tarsal
Navicular (Tarsal Bones)
On the medial side, in front of the talus and proximal to the three cuneiforms
Tuberosity of Navicular (Tarsal Bones)
Projection on the medial side of the navicular; easily seen on the medial border of the foot
Cuboid (Tarsal Bones)
On the lateral side of the foot, proximal (superior) to the fourth and fifth metatarsals and distal (inferior) to the calcaneus
Cuneiforms (Tarsal Bones)
Three in number and named the first through third, going from the medial toward the lateral side in line with the metatarsals. The first is the largest of the three.
Metatarsals
Numbered 1 through 5, starting medially. Normally, the first and fifth metatarsals are weight-bearing bones, and the second, third, and fourth are not. We tend to stand on a triangle. Weight is borne from the base of the calcaneus to the heads of the first and fifth metatarsals.
Bones of the left foot (superior, lateral, and medial views).
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