Plantar fascia Plantar fascia (windlass mechanism) origin medial calcaneal tuberosity insertion base of the 5th metatarsal (lateral band), plantar plate and bases of the five proximal phalanges function increase arch height as toes dorsiflex during toe-off major (2nd most important) medial arch support Hindfoot Overview consists of articulation between talus calcaneus Joints subtalar joint has 3 facets posterior facet this is the largest facet middle facet located medially and sits on the sustentaculum of the calcaneus anterior facet continuous with the talonavicular joint motion inversion/eversion plays no role in plantar and dorsiflexion transverse tarsal joint (Chopart joint) consists of two components talonavicular joint ligament support supported by the spring ligament which consist of superior medial calcaneonavicular ligament inferior calcaneonavicular ligament calcaneocuboid joint anatomy saddle shaped ligament support plantar support is by the superficial and deep inferior calcaneocuboid ligaments superior support is by the lateral limb of the bifurcate ligamant motion inversion of subtalar joint locks the transverse tarsal joint allows for a stable hindfoot/midfoot for toe-off eversion of subtalar joint unlocks the transverse tarsal joint allows for supple foot to accommodate ground just after heel strike plantar aponeurosis is primary structure of load/force transfer between hindfoot and forefoot during stance function works with the subtalar joint to control foot flexibility during the gait cycle Midfoot Overview starts at the articulation between the navicular and cuneiforms consists of articulations between the cuboid and fourth and fifth metatarsals tarsometatarsal joint (TMT joint) Midfoot joints naviculocuneiform and intercuneiform joints connected by a dense ligamentous structure that permits little motion between the joints tarsometatarsal joint(Lisfranc joint) consists of 1st, 2nd and 3rd metatarsocuneiform joints 4th and 5th metatarsocuboid joints divided into three columns medial column first metatarsal medial cuneiform navicular middle column second and third metatarsals middle cuneiform lateral cuneiform lateral column forth and fifth metatarsals cuboid ligament support of the TMT joint composed of three layers interosseus layer contains the Lisfranc ligament origin plantar aspect of the medial cuneiform inserts base of the second metatarsal this is the strongest layer plantar layer next strongest dorsal layer this is the weakest layer motion lateral column is the most mobile allows for flexibility when walking on uneven ground middle column is the least mobile allows for rigidity during push-off medial column carries most of load while standing function functions as a transverse roman arch in the axial plane dorsal surface of the arch is wider than the plantar surface second metatarsal base acts as a keystone Forefoot Overview extends from tarsal-metatarsal joint to tips of toes bones consists of phalanges first phalanx at risk for seymour fracture of distal phalanx must remove nail and interposed physeal tissue, repair nailbed, splint in extension and prescribe antibiotics metatarsals first metatarsal shortest and widest takes 50% of weight during the gait cycle second metatarsal is the longest Joints consists of metatarsophalangeal joints proximal interphalangeal joints distal interphalangeal joints Ligaments and tendons transverse metatarsal ligament function holds hallucal sesamoids in place as 1st MT head moves medially can lead to false image of sesmoid subluxation head is moving, not the sesmoids conjoined tendon of the adductor hallucis muscles broad insertion over the lateral aspect of the lateral sesamoid and lateral aspect of the base of the proximal phalanx plantar plate made up of a dense phalangeosesamoidal complex plantar plate of 2nd MTP must become lax before abnormal dorsal translation of proximal phalanx can occur once attenuated, most deforming force is EDL weakest at origin of metatarsal neck Joint reaction forces second metatarsal experiences more stress during gait most commonly metatarsal to have a stress fracture