1.13 Gait and muscle function

Question 1

What are forces that occur during locomotion?

Answer 1

1. Ground reaction force (GRF)
2. Muscle forces
3. Joint contact forces

Question 2

Describe the relationship between Fy and Fz

Answer 2

For every one component forward (200) Z goes up about 4 components (800)
- orientation of the force within the hypotenuse = magnitude = 8002 + 2002

Question 3

What is kinematics?

Answer 3

Motions of limbs and joints during locomotion

- can also describe the body’s COM snd how it moves through space

Question 4

Define stride

Answer 4

1 stride is when a periodic form of locomotion resets

Question 5

Define stance

Answer 5

Defined per limb as limb in contact with the ground

Question 6

Define swing

Answer 6

Defined per limb as when the limb moves forward

Question 7

Describe the stance phase in relation to the fetlock joint

Answer 7

It effectively hyperextends in gallop

• angle becomes more and more acute
• flexor tendons that runs palmar/plantar get stretched more and more as the joint hyperextends

Question 8

Describe the relationship between kinetics and kinematics at the fetlock

Answer 8

Linear relationship = loading on the tendon is scaling with loading we put on animal
- implications = amount of energy stored in tendons, likelihood of injury

Question 9

Why do neuromuscular disorders effect the swing phase?

Answer 9

Because a complex array of signals coming down from the NS into the motors and trying to coordinate the movement to be both rapid as well as clipping the ground

Question 10

Define gait

Answer 10

specific footfall patterns and mechanics involved in terrestrial locomotion forms
- also based on energetics and force profiles and springs and pendulums

Question 11

Why choose a particular gait?

Answer 11

1. Energetic efficiency
2. Minimise GRFs
   - reduce fatigue (muscle damping)
   - reduce impact on musculoskeletal tissues