Lecture 10 - Midtarsal & Ankle Joints

Question 1

Which joints make up the Midtarsal Joint?

What are it’s 2 axes?

Answer 1

Talonavicular & Calcaneocuboid joint

Function via 2 axes: longitudinal & oblique

Question 2

Describe the anatomical structure of Midtarsal joint

Answer 2

TN joint: ball & socket more motion

CC joint: saddle shaped, provides stability to lateral column

Question 3

List ligaments of MTJ

Answer 3

1. plantar calcaneocuboid
2. long plantar
3. calcaneonavicular (spring)
4. bifurcate ligaments

Question 4

List the MTJ axes of motion

Answer 4

Longitudinal Axis = 9° from SP, 15° from TP (average motions)
- Mostly frontal plane motion
- Absorbs rearfoot rotation, generally functions opposite to STJ; LA pronates when STJ supinates
- 10° of motion
• Oblique Axis = 57° from SP & 52° from

TP (average motions)

• 10° motion
• Mostly sagittal plane & transverse plane motion

Question 5

List relationship of the STJ to MTJ

Answer 5

Elftman described interrelationship of MTJ axes;

• When parallel (to eachother) have maximal motion (pronation)
• When convergent have less motion (supination)

STJ pronation increases MTJ motion = foot flexible (unlocks foot)

STJ supination decreases MTJ motion = foot rigid

Question 6

In ‘Normal’ foot, fully pronated MTJ at both axes does what?

Answer 6

Locks forefoot on rearfoot, with the plantar surface of Ffoot parallel // to Rfoot

Question 7

Traditional Thinking/ Theory of MTJ?

Answer 7

ROM impossible to measure clinically

Categorise into normal, hypermobile or restricted (subjective to clinician)

Question 8

Recent MTJ research indicates?

Answer 8

• Calcaneocuboid & Talonavicular joints should be classifies as separate joints
• Axes continually moving in gait, average motion similar to averages reported
• Motion between cuboid & navicular could be significant
• STJ, CC & TN cannot be separated functionally
• Single axis of motion may be more kinematically sound

Question 9

Which structures for the ankle joint?

Answer 9

Articulation between talus, distal tibia & fibula form ‘ankle mortice’

Question 10

List medial ligaments of ankle joint

Answer 10

Deltoid (tibionavicular, tibiospring & deep posterior tibiotalar)

Question 11

List lateral ligaments of the ankle joint

Answer 11

Anterior & posterior talo-fib & calcaneo-fib

Question 12

Axis of motion of AJ?

Answer 12

8° from FP & 15° from TP

Axis moves during gait like wobbly axle on a wheel

Question 13

Action of AJ?

Answer 13

Plantarflexion/ Dorsiflexion with small adduction & abduction

Question 14

Minimum AJ ROM required for gait?

Answer 14

10° dorsiflexion & 20° plantarflexion

Question 15

List motion of AJ in gait

Answer 15

• Heel contact
• Starts to PF from a 5° DF position to 10° PF position midway through contact. From here it DF
• Midstance
• At start of midstance, AJ is 5° PF & DF until 10° DF at end of phase
• Propulsion
• As heel lifts, PF occurs until 20° PF at toe off
• Swing phase
• Rapid DF to a 5° DF position to allow for foot clearance in swing phase