Lecture 14 - Foot Flashcards
How many bones are in the foot?
- 26 total bones:
- 7 tarsal bones
- 5 metatarsal bones
- 14 phalanges
What are the 7 tarsal bones?
- calcaneus
- talus
- navicular
- cuboid
- cuneiform (3)
What is the calcaneus bone?
- The heel bone
- Posterior, inferior tarsal bone that forms the heel of the foot
- The medial calcaneus has a prominent bony extension called the sustentaculum tali, which supports the medial side of the talus bone
What is the talus bone?
- Articulates superiorly with the tibia & fibula at the ankle joint
- Also articulates inferiorly with the calcaneus bone & anteriorly with the navicular
What is the navicular bone?
- Articulates posteriorly with the talus bone, laterally with the cuboid bone, & anteriorly with the medial, intermediate, & lateral cuneiforms
What is the cuboid bone?
- Articulates posteriorly with the calcaneus, medially with the lateral cuneiform, & anteriorly with the 4th-5th metatarsals
What are the 3 cuneiform bones?
- 1st (medial) cuneiform
- 2nd (intermediate) cuneiform
- 3rd (external) cuneiform
What is the 1st (medial) cuneiform bone?
- the largest of the 3 bones
- it is situated at the medial side of the foot, anterior to the navicular bone & posterior to the base of the 1st metatarsal
What is the 2nd (intermediate) cuneiform bone?
- situated between the other 2 cuneiform bones (the medial and lateral cuneiforms)
- articulates with the navicular posteriorly, the second metatarsal anteriorly & with the other cuneiforms on either side
What is the 3rd (lateral) cuneiform?
- is intermediate in size between the other two cuneiform bones, It occupies the center of the front row of the tarsal bones
- Articulates between the intermediate cuneiform medially, the cuboid laterally, the navicular posteriorly, & the 1st metatarsal in front
What are the metatarsals?
- refer to the five long bones found in each foot. They are numbered I to V, from medial to lateral
- the metatarsal and tarsal bones help to form the main arches of the foot, which are essential for weight-bearing & walking
What are the phalanges of the foot?
- Similar to the fingers, the big toe has proximal & distal phalanges
- The remaining toes have proximal, middle, & distal phalanges
What are the tarsometatarsal joints?
- Between the bases of the metatarsals and the distal row of tarsal bones
- Metatarsal 1- Cuneiform 1
- Metatarsal 2- Cuneiform 2
- Metatarsal 3- Cuneiform 3
- Metatarsal 4 & 5 - Cuboid
What are the metatarsalphalangeal joints?
- Between the heads of the metatarsals and the proximal phalanges
- Joint capsules are reinforced medially and laterally (collateral ligaments) & more flexible on the dorsal & ventral aspects (no palmar plates)
What are the interphalangeal joints?
- the articulations between consecutive phalanges of the foot
- Each foot has 9 interphalangeal joints: 2 on each of the 4 lateral toes & one on the big toe
What are the 2 types of interphalangeal joints?
- Proximal Interphalangeal Joints: between the heads of the proximal phalanges and the base of the middle phalanges
- Distal Interphalangeal Joints: between the heads of the middle phalanges and bases of the distal phalanges
What are the 3 arches of the foot?
- medial longitudinal arch
- lateral longitudinal arch
- transverse/mid-tarsal arch
What is the medial longitudinal arch?
- Larger, taller arch
- Formed by calcaneal tuberosity, talus, navicular, cuneiforms (3) & 1st 3 metatarsals
- Supported by the Spring ligament & Plantar Fascia
What is the lateral longitudinal arch?
- Relatively flat, lower than the medial arch
- Supported by the long plantar ligament, short plantar ligament, bifurcate ligament, & planter fascia
What is the transverse/mid-tarsal arch?
- Forms a medial-lateral curvature of the mid-foot
- Created by the bases of metatarsals 1-5
What are the 2 types of arch heights?
- pes planus
- pes cavus
What is pes planus?
- the loss of the medial longitudinal arch of the foot, heel valgus deformity, and medial talar prominence
- Known as “flat foot’
What is pes cavus?
- A foot with an abnormally high plantar longitudinal arch
What is the talocrural joint?
- formed between the distal tibia-fibula and the talus, & is commonly known as the ankle joint
- It is a hinge joint & allows for dorsiflexion and plantarflexion movements in the sagittal plane