Sagittal Plane

Question 1

what is the creation of power for efficient forward motion?

Answer 1

1. pull placed on the swing limb is the most powerful source that acts on the body’s centre of mass
2. momentum provides continuation of motion
3. gravity permits the body to use its own mass, by acting on the trunk when it is placed just in front of the planted foot
4. elastic tissue response represents a complex form of energy return. energy that is stored at impact is returned

Question 2

what are the premises of the sagittal plane theory?

Answer 2

premises

• the foot must be able to resist forces that are applied to it
• this must coordinate with the power input which is required to move the body forward over the foot
• the foot has 3 autosupportive mechanisms

Question 3

What are the auto supportive mechanisms?

Answer 3

• Calcaneocuboid locking
• the locking wedge and truss effect
• the windlass effect

Question 4

Explain high gear vs low gear theory?

Answer 4

• larger thrust is gained through high gear propulsion where medial slip of plantar aponeurosis is seen during gait. Its believed this is the windlass.
• low gear propulsion is less effective and requires more muscular involvement

Question 5

what can cause a Sagittal plane block?

Answer 5

• first ray 1st MPJ motion impeded

- talus adduction, adduction RF on FF therefore TP force greater than SP force

Question 6

What is function and structural hallux limitus?

Answer 6

hallux limitus
-no efficient 1st ray dorsiflexion

Functional
-reduced or inadequate 1 MPJ motion during gait while maintain adequate ROM of during non weight bearing examination

Structural

• primary and secondary deformities such as OA
• non weightbearing and weightbearing

Question 7

List and describe the compensation mechanism for sagittal plane blockage?

Answer 7

Altered heel lift

• no Df of 1st MPJ, Df occurs somewhere else
• flexible foot compensation through MTJ, collapse and Df occurs

Vertical toe off

• apropulsive gait, foot lifted off the ground before propulsion
• slow movement low energy efficient

inverted step

• occurs when weight fails to move medially
• due to no calcaneocuboid locking, forefoot valgus
• excessive wearing of lateral shoe

Abducted and adducted toe off
-abductory twist occurs if the body can no longer move forward to compensate
compensation

Flexion compensation of the body

• if the body cannot come over efficiently abnormal torso flexion occurs
• straightened spine and HS, flexed head and neck overtime leads to chronic postural change

Question 8

Explain the calcaneobuboid locking?

Answer 8

• Dependent of tension of plantar fascia
• During heel lift plantar fascia tightens which enables locking of calcaneocuboid
• thus allowing shift of weight from lateral to medial

Question 9

Explain the two metatarsal head axes system?

Answer 9

• during heel lift foot must move from OA 2-5 to TA 1-2 to efficiently move over the foot

Question 10

explain the locking wedge and truss effect?

Answer 10

• describes foot moving from midstance where metatarsals are parallel to the ground to being perpendicular
• fulcrum effect, met being perpendicular to surface more effectively the foot can transfer weight
• increase rearward thrust and forward momentum

Question 11

Explain the windlass mechanism?

Answer 11

• DF of hallux at heel lift, tightens plantar fascia
• plantar fascia pulls hallux into metatarsals
• there is then a equal opposite force to further DF the hallux
• A Pf moment is created by the medial cuneiform force acting on base of met

-overall Pf moment from windlass over powers Df moment created