Biomechanic Principles

Question 1

Newtons 1st law

Answer 1

Law of inertia
A body remains at rest or constant linear velocity until an external force changes its state.

A body remains at rest or constant angular velocity around an axis of rotation unless an external torque changes its state

Question 2

Moment of inertia definition

Answer 2

Resistance to change in angular velocity

Question 3

Moment of inertia is dependent on what?

Answer 3

Mass

Distance of mass from the axis of rotation

Question 4

Shortening the distance of mass from the axis will have what effect on inertia?

Answer 4

Reduce inertia ( decreasing amount of torque required for movement)

Question 5

How can you control the moment of inertia?

Answer 5

Changing the position of the body (this will change angular velocity)

Question 6

Newtons 2nd Law

Answer 6

Linear acceleration is directly proportional to the force causing it and inversely proportional to mass.

Angular acceleration is directly proportional to the torque causing it and inversely proportional to the moment of inertia of the body.

Question 7

Newtons 3rd law

Answer 7

Action-reaction

For every force, there is an equal and opposite force

Question 8

According to the kinetic link principle, proximal segments are used to _____________ , which is __________________________ when the first segment _____.

Answer 8

Generate momentum
Transferred to the next segment
Stops

Question 9

According to the kinetic chain principle, velocity tends to ___________ as it travels distally. Why?

Answer 9

Increase

Because segments tend to get smaller

Question 10

Ways to objectively measure human movement

Answer 10

Electrogoniometry
Accelerometery
Motion Capture

Question 11

This measures the joints angular rotation during motion

Answer 11

Electrogoniometer

Question 12

Measures acceleration of either a segment or the whole body

Answer 12

Accelerometer