Gait Kinetics

Question 1

What occurs during Initial contact TO 1st Peak (F1)?

Answer 1

• Body Decelerates downwards
• COM is lower hence increasing the GRF measurement
• Weight being transferred from back foot to front foot

Question 2

What occurs during 1st peak (F1) TO Trough (F2)?

Answer 2

• Increase in the COM
• Decrease in GRF
• Extension of the knee increases the COM
• Decrease in the reaction force (causing the trough)
• Deceleration of body

Question 3

What occurs during Trough (F2) TO 2nd Peak (F3)?

Answer 3

• COM falls as the heel lifts
• Foot is pushed down and back into the ground (increasing GRF)
• Indicated the Propulsive phase

Question 4

What occurs during 2nd Peak (F3) to TO?

Answer 4

Foot is unloaded as the load is transferred to the opposite foot

Low COM

Duration of this phase is relative to the speed of transfer to the opposite foot

Question 5

What is Claw back Transient?
What causes it?

Answer 5

An anterior GRF at the Heelstrike

Caused by backward velocity during the heel strike
- Often seen when marching –> the push of the foot down and backwards

Question 6

What is Heel-Strike Transient?
Cause?

Answer 6

A Vertical GRF at HS

• Hard shoes causes a more abrupt striking of the foot
• Overstriding

Question 7

Differences between Anterior and Posterior GRF during the Gait Cycle
(When does each peak occur? Why?)

Answer 7

Peak Posterior GRF
- Occurs early in the stance phase
- Heel contact and body deceleration causes this
- Decreases as the body moves over the fixed limb

Anterior GRF
- Occurs late in the stance phase (preparing for the propulsion phase)
- Propelling the body forward
- Occurs during the body weight transfer to new stance limb