Medial longitudinal arch is formed by tarsal bones and metatarsals
Lateral longitudinal arch is not as well formed
Slight transverse arch passing through distal tarsal bones goes from side to side
Arches are maintained by several foot structures
The Talus bone of the foot
Is the keystone that keeps the integrity of arches
Wedged between calcaneus and navicular bone.
Also maintained by ligaments
Large series of ligaments that tie bones together on plantar surface and dorsal surface (from flexor hallucis longus etc.)
Intrinsic muscles of the foot
Extrinsic foot muscles such as fibularis longus which crosses ankle and goes across plantar foot to first metatarsals which acts as “hooks” to keep arch
Moral of the story: Bone structure, ligaments, intrinsic muscles, extrinsic muscles must be intact for arches to remain stable.
Ligaments of the Ankle joint:
Series of ligaments from medial malleolus to bones of the foot (tarsals)
4 of them, named by bones they attach- called the Deltoid ligament. Is shaped like a triangle.
Thus, major ligament of medial ankle joint is deltoid ligament.
These are very tough ligaments.
May have medial malleolus portion pulled off before tear the ligament.
Calcanealfibular ligament
from tip of the fibula to the calcaneus
On the lateral aspect of ankle
Greatest stress to this ligament would be on inversion movements
Thus this ligament is commonly stretched beyond limits by misstep = sprained ankle / rolled ankle.
On plantar surface of the foot: 2 key ligaments
Long plantar ligament: acts to maintain arch- distributes to toes 2-5
Plantar calcaneonavicular ligament:
Connects calcaneus to navicular bone on plantar surface
Supports the head of the Talus- articulates with the navicular bone.
AKA Spring ligament – gives recoil to arches of the foot.
