Lecture 1

Question 1

What is kinematics?

Answer 1

Study of motion without regard to forces causing the motion.

Question 2

What are the components of movement?

Answer 2

Translation + rotation.

Question 3

What are the key variables in kinematics?

Answer 3

Position, Displacement, Velocity, Acceleration.

Question 4

What is a global coordinate system?

Answer 4

Fixed to a point in space, 3D.

Question 5

What is a local/anatomic coordinate system?

Answer 5

Fixed to a rigid body, 2 local coordinates compared to determine joint angle.

Question 6

How many degrees of freedom are in a 3D system?

Answer 6

6 degrees of freedom (3 translation, 3 rotation).

Question 7

What is kinetics?

Answer 7

Study of motion under forces.

Question 8

What is moment/torque?

Answer 8

Acceleration x force, force distant to a centre of rotation.

Question 9

What are the key concepts in kinetics?

Answer 9

Work, Power, Energy.

Question 10

What is Newton’s 1st Law?

Answer 10

Object at rest remains at rest or continues moving at constant velocity unless acted upon by an unbalanced external force.

Question 11

What does the sum of forces and moments equal in Newton’s 1st Law?

Answer 11

Sum of F = 0, Sum of M = 0.

Question 12

What is Newton’s 2nd Law?

Answer 12

Unbalanced force acting on an object produces acceleration in the direction of the force.

Question 13

What is the formula for Newton’s 2nd Law?

Answer 13

F = ma.

Question 14

What is Newton’s 3rd Law?

Answer 14

For every action there is a reaction equal in magnitude but in the opposite direction.

Question 15

What is anthropometry?

Answer 15

Study of physical measurement of the human body.

Question 16

What does anthropometry measure?

Answer 16

Segment length, segment mass, centre of mass location, radius of gyration.

Question 17

What is the centre of mass?

Answer 17

Point on which any line passing through it divides the body in half.

Question 18

How is the centre of mass characterized?

Answer 18

Mass equally distributed, changes with movement, can be found for segments or whole body.

Question 20

What is Kinematics?

Answer 20

Kinematics is the study of motion, including the measurement of position, velocity, acceleration, and joint angles.

Question 21

What are motion capture systems used for?

Answer 21

Motion capture systems measure position, velocity, acceleration, and joint angles.

Question 22

What are the types of motion capture systems?

Answer 22

1. Camera
2. Optoelectric, electromagnetic, and ultrasound
3. Inertial sensors
4. Markerless systems

Question 23

How do optoelectric systems work?

Answer 23

Optoelectric systems use markers that emit (active) or reflect (passive) infrared light, which cameras then identify for position measurement.

Question 24

What are the advantages of optoelectric systems?

Answer 24

Advantages include high accuracy, the ability to be wireless, and not being influenced by metals.

Question 25

What are the disadvantages of optoelectric systems?

Answer 25

Disadvantages include the potential for markers to be occluded and post-processing time with some systems.

Question 26

How do electromagnetic systems operate?

Answer 26

Electromagnetic systems use receivers (markers) that pick up a magnetic field emitted by a transmitter.

Question 27

What are the advantages of electromagnetic systems?

Answer 27

Clear line of sight is not necessary.

Question 28

What are the disadvantages of electromagnetic systems?

Answer 28

Disadvantages include metal interference, limited range, and the need for wires.

Question 29

What is an electrogoniometer?

Answer 29

An electrogoniometer measures joint angles during movement by detecting changes in electrical current when the device is bent.

Question 30

What are the advantages and disadvantages of electrogoniometers?

Answer 30

Advantages: cheap, simple. Disadvantages: difficult to align, movement can be limited by the device.

Question 31

What do accelerometers measure?

Answer 31

Accelerometers measure acceleration and can determine net force, velocity, or displacement, and monitor physical activity.

Question 32

What are force transducers?

Answer 32

Force transducers are devices that measure strength (F) and can be isokinetic, hand-held, or used for grip strength.

Question 33

What is electromyography?

Answer 33

Electromyography measures muscle activation during different activities using indwelling or surface electrodes.

Question 34

What do pressure sensors measure?

Answer 34

Pressure sensors measure plantar pressure and utilize different technologies, including piezoelectric.