Module 2 Wrap-up
In this module, we reviewed the components of both optical and electromagnetic 3D motion analysis systems. We also outlined the advantages and disadvantages of each type of system, and briefly discussed partial analysis systems.
Answer the following self check questions to monitor your understanding of the material presented thus far.
Self check questions:
1. Optical systems typically use which of the following frame rates to capture motion of the golfer?
Incorrect.
The correct answer is 240 fps. 240 frames per second are most commonly used for tracking movements of the body. Standard TV and video cameras record at 30-60 fps, which is much too slow to accurately measure many of the movements of the golfer. To examine movements of the club head going into impact, data need to be sampled or resampled/calculated to about 1,000 fps. Radar-based ball flight monitors typically sample at over 20,000 frames (or samples) per second. This kind of speed is only required when trying to determine flight of the ball. (See the page: Optical System Components)
Correct.
240 frames per second are most commonly used for tracking movements of the body. Standard TV and video cameras record at 30-60 fps, which is much too slow to accurately measure many of the movements of the golfer. To examine movements of the club head going into impact, data need to be sampled or resampled/calculated to about 1,000 fps. Radar-based ball flight monitors typically sample at over 20,000 frames (or samples) per second. This kind of speed is only required when trying to determine flight of the ball. (See the page: Optical System Components)
Incorrect.
The correct answer is 240 fps. 240 frames per second are most commonly used for tracking movements of the body. Standard TV and video cameras record at 30-60 fps, which is much too slow to accurately measure many of the movements of the golfer. To examine movements of the club head going into impact, data need to be sampled or resampled/calculated to about 1,000 fps. Radar-based ball flight monitors typically sample at over 20,000 frames (or samples) per second. This kind of speed is only required when trying to determine flight of the ball. (See the page: Optical System Components)
Incorrect.
The correct answer is 240 fps. 240 frames per second are most commonly used for tracking movements of the body. Standard TV and video cameras record at 30-60 fps, which is much too slow to accurately measure many of the movements of the golfer. To examine movements of the club head going into impact, data need to be sampled or resampled/calculated to about 1,000 fps. Radar-based ball flight monitors typically sample at over 20,000 frames (or samples) per second. This kind of speed is only required when trying to determine flight of the ball. (See the page: Optical System Components)
2. Which type of plate records vertical forces only?
Correct.
Both pressure plates and force plates record vertical forces. But, only force plates are capable of also recording anterior-posterior and lateral forces. (See the page Force Plates and Pressure Plates)
Incorrect.
The correct answer is pressure plate. Both pressure plates and force plates record vertical forces. But, only force plates are capable of also recording anterior-posterior and lateral forces. (See the page: Force Plates and Pressure Plates)
3. Which type of plate is typically more mobile with a shorter setup time?
Correct.
Pressure plates (or mats) tend to be very portable and can be laid down on most firm surfaces.(See the page: Force Plates and Pressure Plates)
Incorrect.
The correct answer is Pressure plate. Pressure plates (or mats) tend to be very portable and can be laid down on most firm surfaces. (See the page: Force Plates and Pressure Plates)
4. In an optical system, each individual camera gives a 2-dimensional picture, and can't show depth, or how far away from the camera a marker is. Therefore, we use multiple cameras to be able to measure movements in 3D. Can a regular video camera show depth and be used to analyze 3D motions?
Incorrect.
The correct answer is no. All standard cameras create 2D pictures. We may try to interpret 3D information from 2D images, but a single camera view can not be used to measure 3D movement.
Correct.
All standard cameras create 2D pictures. We may try to interpret 3D information from 2D images, but a single camera view can not be used to measure 3D movement.