Qualitative Analysis, Signals and Filtering

Question 1

Framework for Qualitative Analysis

Answer 1

1. Describe Ideal Techniques
2. Observe the Performer
3. Evaluate the Performance
4. Instruct the Performer

Question 2

Qualitative Determinant Analysis Model

Answer 2

1. Identify the exact performance variable
2. Break this variable into components
3. Assess relative importance of components

Question 3

What is Style?

Answer 3

The way the person performs a movement or activity
E.g. a runners style might refer to their overall approach to running, such as stride length, arm swing and foot placement

Question 4

What is Technique?

Answer 4

Refer to specific mechanics or form used to execute the movement
E.g. specific running mechanics such as foot strike, knee positioning and hip extension.

Question 5

What is Amplitude?

Answer 5

A Measure of how much the signal changes in size
- Indicated by the height of the vertical axis

Question 6

What is frequency?

Answer 6

A measure of how fast the signal changes
- Measured in oscillations per second

Question 7

What is Fourier Analysis?

Answer 7

Based on the concept that any function can be represented by a sum of weighted sine and cosine functions.
- Every wave can be approximated by summing whole series of sine waves with different frequencies

Allows us to calculate amplitude of each frequency present in the signal.

Question 8

What is Nyquist Sampling Theorem?

Answer 8

Sampling rate must be equal to or greater than twice the highest frequency component in the analog signal
The Theorem defines the minimum sample rate for the highest frequency that you want to measure
e.g. a frequency of 2Hz has a sampling rate of 4 Hz

Question 9

What is a low pass filter?

Answer 9

Enables smoothing of data to remove errors in a signal
Provided those errors are at a higher frequency than the movement that is being studied
Is applied to data after digitising to remove small errors