Foot Osteology Flashcards
The foot overview
26 Bones + 2 sesamoids
❖57 Joints
❖Flexible yet rigid
❖Adaptable yet strong
❖Withstand high forces
*Ground reaction forces
*Body weight
Calcaneus
❖The largest of
the tarsal bones.
❖Posterior surface
is the attachment
for the Achilles
tendon.
Sinus Tarsi
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
Navicular
❖Medial aspect bone
❖Boat shaped
❖Attachment for muscles
Cuneiforms
3
medial, Intermediate and lateral
Cuboid
❖Lateral tarsal bone
❖Attachment site for
muscles
❖Articulates with 4th
and 5th metatarsals
Metatarsals
1st= medial side of the foot
5th= lateral side of the foot
Phalanges
Proximal, middle, distal
First toe only has proximal and distal
sometimes 5th toe to
The Foot joints
6
Proximal/Distal
interphalangeal (PIP, DIP)
joints
*Metatarsophalangeal
(MTP) joints
*Tarso-metatarsal joints
*Cuboideonavicular joint
*Calcaneocuboid
*Talocalcaneonavicular
joint
Ankle > foot joints
Distal Tibiofibular
Talocrural
Subtalar
Sub Talar joint
❖Modified multi-axial synovial joint
❖Inferior Talus concave
❖Surface of Calcaneus convex
Inversion 0-35
eversion 0-20
Arches of the foot
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
Arches of the foot
longitudinal arch
◦ 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
Arches of the foot
transverse arch
Formed between the medial and lateral arches and includes the navicular, three cuneiforms and the bases of the five metatarsals
Plantar Fascia/ Aponeurosis
collagen
from calcaneus to proximal phalanges
little ability to lengthen
allows for stability and rigidity
windlass mechanism
Movements at foot joints
7
Inversion
*Eversion
*Toe Flexion
*Toe Extension
*Toe Abduction
*Toe Adduction
*Great Toe Abduction/Adduction
Combined movements of the Subtalar and
transverse (mid) tarsal joints
inversion 0-45 degrees
eversion 0-20 degrees
Extension and flexion of the toes
EXTENSION
0-60 degrees of ROM available
during toe extension
FLEXION
0-40 degrees of ROM available during
toe flexion
Joint Capsule
Joint capsule – fibrous attaches to articular margins; weak ant and post to accommodate DF and PF; strengthened medially and laterally by collateral ligaments
Synovial Membrane
Synovial membrane – lines capsule; loose; extends between tibia and fibula as far a Inf TF joints
Stability joint depends on
- muscles around the joint,
- supporting ligaments
- bony contours – concave surface of tibia – convex (dome shape) surface of talus.