ATTR 219 Lecture 4Foot, Ankle and Lower Leg-medial malleolus- tibia-lateral malleolus-fibula (longer than tibia)Foot and ankle consists of 26 bones:- 7 tarsals- 5 metatarsals- 14 phalangesTarsals- Major structures are the head, neck and dome- Talocrural joint/ankle mortise- superior surface with tibia- Subtalar joint- plantar surface of talus with calcaneus-Calcaneus (heel)-lateral calcaneal-medial calcaneal- important due to attachment of plantar aponeurosis or plantar fasciaMedial portion of calcaneus helps support talus and is known as sustentaculum taliNavicular-navicular tuberosity-provide primary attachment for posterior tibialis tendonCuboidThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.-groove for peroneus longus muscleMetatarsals-each has base, body and head numbered one through five (big toe #1, smallest toe #5)-tarsometatarsal joints-articulates with proximal philanges to form metatarsophalangeal (MTP) jointsPhalanges-each foot has 14 phalanges -hallux/big toe only has 2, rest of toes each have 3- consists of base, body and head-interphalangeal joints (IP joints)-proximal interphalangeal joint (PIP)-distal interphalangeal joint (DIP)Arches of Foot-longitudal arches (medial and lateral)-medial arch-higher, more mobile and resilient than the lateral-pescavis- high medial arch-pesplantis- low/no arch-transverse arch- under tarsal bones-metatarsal arch- balls of feetWeight Baring on FeetMost weight is put on:1. Posterior calcaneus2. Five metatarsal heads at ball of feet (mostly on 1st and 5th)Muscles of Plantar Aspect of Foot-grouped into 4 layers1. First/superficial Layer-Abductor Hallucis- big toeOrigin: Medial calcaneus tubercleInsertion: Base of proximal phalanx of big toeAction: Abducts and assists in big toe flexion-Flexor digitorium brevisOrigin: lateral calcaneus tubercleInsertion: middle phalanx of lateral 4 toesAction: flexes lateral four toes-Abductor digiti minimiOrigin: laterl calcaneus tubercleInsertion: base of proximal phalanx of 5th toeAction: abducts assists in flexion of 5th toe2. Second Layer-Quadratus PlantaeOrigin: Medial and lateral plantar surface of calcaneus Insertion: tendon of flexor digitorium longusAction: assists in flexing lateral four toes-LumbricalsOrigin: Tendon of flexor digitorium longusInsertion: medial side of proximal phalanx of lateral 4 toesAction: Flexes MPT