8.10 Technology

Question 1

What is motion capture used for in movement analysis?

Answer 1

To record and analyze human movement for gait, sports, and research applications.

Question 2

Where did motion capture technology originate?

Answer 2

It originated in gait analysis.

Question 3

How does a reflective marker motion capture system work?

Answer 3

Reflective markers are placed on specific body points, and multiple cameras record their movement in 3D space.

Question 4

What additional equipment is often used with motion capture systems?

Answer 4

Force plates, which measure ground reaction forces and stability or sway limits.

Question 5

What kind of data can motion capture systems provide?

Answer 5

Joint angles, ranges of motion, center of mass, and stability limits.

Question 6

What does a surface EMG (electromyography) measure?

Answer 6

Electrical activity of muscles through electrodes placed on the skin.

Question 7

What information can EMG provide about muscle activity?

Answer 7

Which muscles are active, timing and intensity of contractions, and coordination between agonists and antagonists.

Question 8

Why is caution needed when interpreting EMG amplitude data?

Answer 8

Because amplitude is influenced by factors like tissue resistance, electrode placement, and muscle length changes.

Question 9

Why should EMG amplitude not be compared directly between people or days?

Answer 9

Because individual and setup differences affect absolute values; data should be converted to relative measures.

Question 10

What principle are force plates based on?

Answer 10

Newton’s Third Law — every action has an equal and opposite reaction.

Question 11

What do force plates measure?

Answer 11

Ground reaction forces during walking, running, jumping, or balance tasks.

Question 12

What can force plate data be used to analyze?

Answer 12

Postural stability, power, reaction forces, direction of movement, and muscle activation timing.

Question 13

What is a pressure-sensitive walkway used for?

Answer 13

Measuring temporal and spatial parameters of gait such as step length, cycle time, and base of support.

Question 14

What is one example of a pressure-sensitive walkway system?

Answer 14

GAITRite.

Question 15

What type of data does GAITRite provide?

Answer 15

Step time, cycle time, stride length, single and double support time, and visual gait patterns.

Question 16

What does an accelerometer measure?

Answer 16

Acceleration to quantify gait characteristics.

Question 17

What is an IMU and what does it measure?

Answer 17

An inertial measurement unit that measures angular velocity (via gyroscope) and acceleration (via accelerometer).

Question 18

Where can accelerometers or IMUs be placed?

Answer 18

On different body segments depending on which movement is being analyzed.

Question 19

What do wearable technologies like smartwatches measure?

Answer 19

Walking speed, step length, double support time, walking asymmetry, and stair climbing speed.

Question 20

Why might smartwatch data be clinically useful?

Answer 20

It provides real-world movement information outside of the clinic environment.