Lower leg and foot: Foot arthrology Flashcards
What are the 4 functions of the foot?
- Base of support
- Adapt to uneven surfaces
- Shock absorber
All 3 of these need to be able to absorb stress and it needs to be flexible - Propulsion
This requires foot to be rigid (stress transmission)
What are the 3 main foot arches?
Medial Arch (highest arch, no contact with the ground, flexible)
Lateral Arch (flatter than medial arch, in contact with ground, more rigid than medial arch)
Anterior Transverse Arch (relatively flat, contacts ground)
What is the area supported by the 3 arches called and what are its 3 contact points to the ground?
Plantar Vault (functional middle section of foot) Contacts ground at 3 points:
A= Head Metatarsal I
B= Head Metatarsal V
C= Calcaneal Tuberosity
What 5 bones is the Medial Arch of the foot made from?
o Calcaneus (Ca)
o Talus (T)
o Navicular (N)
o Medial cuneiform (Cun)
o Metatarsal I (MT1)
What 3 bones is the Lateral Arch of the foot made from?
o Calcaneus (Ca)
o Cuboid (Cu)
o Metatarsal 5 (MT5)
What bones are the Anterior Transverse Arch of the foot made from?
Formed by heads of 5 metatarsals
What stabilises an arch?
Shapes of bones
Strength of support
How do the shapes of bones stabilise an arch?
Wedge-shaped bones interlock, keeping them together.
This relies on top ‘keystone’ for support
Strength of support - There are 3 types of support. Name and explain each Support Type.
Support Type 1 – ‘Staples’ (Bones bound together underneath to prevent them being separated by weight)
Support Type 2 – ‘Tie Beam’ (Connects 2 end of the arch and prevents separation when weightbearing) (Plantar Fascia)
Support Type 3 – ‘Sling/Suspension’ (Arch supported from above by cable) (Peroneus Longus)
What are the 4 ‘stages’ of walking?
Heel strike
Stance phase
Heel off
Toe off
During heel strike, what bone is the weight through and what are the arches doing?
o Weight is through calcaneus
o Arches are raised
During stance phase, what happens to the vault and what do the muscles do?
o Vault is flattened – shock absorption
o Muscles contract to stop further flattening: ‘Plantar Tighteners’
During heel off, what do plantar tighteners do?
Plantar tighteners contract further
During toe off, what happens when big toe extends (what is the mechanism called?)
As big toe extends, plantar fascia tightens, reinforcing medial arch – ‘Windlass Mechanism’
What 2 movements can occur when the foot is OFF the floor?
Inversion and Eversion
What 3 movements occur during inversion?
Plantarflexion, Adduction, Supination
What 3 movements occur during eversion?
Dorsiflexion, Abduction, Pronation
What joint does movement occur at at the Hindfoot?
Subtalar Joint (between Calcaneus and Talus)
What joint does movement occur at at the Forefoot?
Midtarsal Joint (2 joints in 1)
What are the two joints that make up the Midtarsal Joint?
Talonavicular joint (between Talus and Navicular)
Calcaneocuboid joint (between Calcaneus and Cuboid)
What 2 movements occur when the foot is ON the floor?
Pronation and Supination
What is the difference between ‘Inversion and Eversion’ and ‘Pronation and Supernation’?
During Inversion and Eversion, the forefoot and hindfoot are moving in the same direction, doing the same thing
Pronation and Supination, in order for foot to stay on floor, when forefoot rolls in, hindfoot has to stay out and vice-versa (move in opposite directions)
What movements occur at Hindfoot during pronation? (See table in document for image)
Adduction, Pronation, Plantarflexion
What movements occur at Forefoot during pronation? (See table in document for image)
Abduction, Supination, Dorsiflexion
What movements occur at Hindfoot during supination? (See table in document for image)
Abduction, Supination, Dorsiflexion
What movements occur at Forefoot during supination? (See table in document for image)
Adduction, Pronation, Plantarflexion
