L29

Question 1

Dynamic Analysis can be:

Answer 1

Linear : F=ma
And angular: T= Ia

Question 2

When to use dynamic analysis

Answer 2

When acceleration is not zero

Question 3

Inverse dynamics

Answer 3

Calculates the forces/ torques based on the accelerations of the object instead of measuring the forces directly
-usually newtons 2nd law of acceleration

Question 4

Foot Swinging during Gait broken down:

Answer 4

Rankle- Tr (x direction) -Tr (y direction)= Inertia x angular acceleration

Question 5

Angular Work

Answer 5

= Torque x change in anglular distance (radians)

Question 6

Positive Work=

Answer 6

Concentric muscle actions (shortening)

Question 7

Negative Work

Answer 7

Eccentric muscle actions (lengthening)

Question 8

Angular Power

Answer 8

Angular work done per unit of time
W/ t
Or Torque x angular velocity

Question 9

Next moment/ torque

Answer 9

Describes the net muscle activity across a joint
-does not represent any one particular muscle that crosses the joint, but the net activity of all muscles

-can be used in part with the angular velocity of the joint to determine concentric or eccentric

Question 10

Net muscle activity at a joint

Answer 10

Flexor or extensor actions
-whether the muscle activity is concentric or eccentric cannot be observed directly from the joint movement

Question 11

Power or muscle

Answer 11

= Mj x w j
Mj= moment/ torque at joint
W j= angular velocity of the joint

Question 12

Rotational Kinetic Energy

Answer 12

RKE= 1/2 I w^2I= moment of inertia
W= angular velocity in radians