Tarsometatarsal joints, supporting, propulsion, and shock absorbing mechanisms of the foot (dave's notes)

Question 1

How does the metatarsus differ from the metacarpus?

Answer 1

The metatarsus is much more rigid than the metacarpus.

• No opposition is possible at the big toe
• Second tarsometatarsal joint is immobile.

Question 2

Describe the interphalangeal joints of the toes relaltive to those of the fingers

Answer 2

Similar to the hands, with capsules and interphalangeal ligaments.

Question 3

What are the components of the supporting mechanism of the foot?

Answer 3

Medial longitudinal arch
Lateral longitudinal arch
Transverse arch

Question 4

What are the components of the medial longitudinal arch of the foot?

Answer 4

Calcaneus, talus, navicular, and the three cuneiform bones (with their metatarsals)

Question 5

What is the most important ligamentous component that maintains the medial longitudinal arch?

Answer 5

The ligaments are important, with the plantar aponeurosis the most important.

Question 6

What is the role of muscles in supporting the medial longitudinal arch? Which muscles?

Answer 6

Indispensable, especially FHL which acts as a bowstring and TA/TP which draw on the medial aspect of the foot.

Question 7

What are the components of the lateral longitudinal arch?

Answer 7

The calcaneus, cuboid and the lateral two metatarsals, and the plantar aponeurosis which acts as a bow-string.

Question 8

What are the components of the transverse arch 9hemi-arch)? How does bone shape assist with this? What is more important than bone shape in maintaining this arch?

Answer 8

The bases of the five metatarsals and the adjacent cuboid and cuneiforms. The bones are wedge shaped assisting with the shape. The ligaments are much more important still.

Question 9

What movements enhace propulsive action of the foot? Which muscles are most important?

Answer 9

Arching of the foot and flexion of the toes enhance propulsive action of the ankle joint. FHL is very important, and short flexor muscles further assist.

Question 10

In order of least to most important list the muscles aht enhance the propulsive mechanism of the foot.

Answer 10

Bottom gear: Soleus
Top gear: Gastrocnemius
Overdirve: Tarsal flexors

Question 11

What is the shock absorbing mechanism of the foot?

Answer 11

On landing it is the toes and then the forefoot which take the load. This is opposite from normal. Muscles play an important role.