Foot Osteology

Question 1

The foot overview

Answer 1

26 Bones + 2 sesamoids
❖57 Joints
❖Flexible yet rigid
❖Adaptable yet strong
❖Withstand high forces
*Ground reaction forces
*Body weight

Question 2

Calcaneus

Answer 2

❖The largest of
the tarsal bones.
❖Posterior surface
is the attachment
for the Achilles
tendon.

Question 3

Sinus Tarsi

Answer 3

Space formed by sulcus tali and
calcaneal sulcus
- Visible from lateral side
- Contains neural tissue for
proprioception (understanding
where a joint is in space) and
nociception (pain receptors)

Also contains blood
vessels and soft tissue

Question 4

Navicular

Answer 4

❖Medial aspect bone
❖Boat shaped
❖Attachment for muscles

Question 5

Cuneiforms

Answer 5

3
medial, Intermediate and lateral

Question 6

Cuboid

Answer 6

❖Lateral tarsal bone
❖Attachment site for
muscles
❖Articulates with 4th
and 5th metatarsals

Question 7

Metatarsals

Answer 7

1st= medial side of the foot
5th= lateral side of the foot

Question 8

Phalanges

Answer 8

Proximal, middle, distal

First toe only has proximal and distal
sometimes 5th toe to

Question 9

The Foot joints
6

Answer 9

Proximal/Distal
interphalangeal (PIP, DIP)
joints

*Metatarsophalangeal
(MTP) joints

*Tarso-metatarsal joints

*Cuboideonavicular joint

*Calcaneocuboid

*Talocalcaneonavicular
joint

Question 9

Ankle > foot joints

Answer 9

Distal Tibiofibular

Talocrural

Subtalar

Question 10

Sub Talar joint

Answer 10

❖Modified multi-axial synovial joint
❖Inferior Talus concave
❖Surface of Calcaneus convex

Inversion 0-35
eversion 0-20

Question 11

Arches of the foot

Answer 11

Formed by tarsals, metatarsals, muscles, and ligaments
Function:
◦ To support body weight
◦ Distribute body weight

3 arches – medial, lateral, and transverse;

transverse arch is considered in 2 parts – anterior and posterior

Question 12

Arches of the foot

longitudinal arch

Answer 12

◦ Formed of medial and lateral parts

◦ Medial – calcaneus, rises to calcaneus, descends through navicular, three cuneiforms and head of three metatarsals

◦ Lateral – rises at cuboid, descends to two lateral metatarsals

Question 13

Arches of the foot

transverse arch

Answer 13

Formed between the medial and lateral arches and includes the navicular, three cuneiforms and the bases of the five metatarsals

Question 14

Plantar Fascia/ Aponeurosis

Answer 14

collagen

from calcaneus to proximal phalanges

little ability to lengthen

allows for stability and rigidity

windlass mechanism

Question 15

Movements at foot joints
7

Answer 15

Inversion
*Eversion
*Toe Flexion
*Toe Extension
*Toe Abduction
*Toe Adduction
*Great Toe Abduction/Adduction

Question 16

Combined movements of the Subtalar and
transverse (mid) tarsal joints

Answer 16

inversion 0-45 degrees
eversion 0-20 degrees

Question 17

Extension and flexion of the toes

Answer 17

EXTENSION
0-60 degrees of ROM available
during toe extension
FLEXION
0-40 degrees of ROM available during
toe flexion

Question 18

Joint Capsule

Answer 18

Joint capsule – fibrous attaches to articular margins; weak ant and post to accommodate DF and PF; strengthened medially and laterally by collateral ligaments

Question 19

Synovial Membrane

Answer 19

Synovial membrane – lines capsule; loose; extends between tibia and fibula as far a Inf TF joints

Question 20

Stability joint depends on

Answer 20

1. muscles around the joint,
2. supporting ligaments
3. bony contours – concave surface of tibia – convex (dome shape) surface of talus.