Motion analysis

Motion analysis is a technique used to measure the movement of an individual or object using various tools such as cameras, sensors, and software. This study guide will cover some of the key concepts related to motion analysis.

1. Be able to design a research project which evaluates the effect of a given device (e.g. a knee immobilizer, an ankle brace, etc.) on the gait pattern of a subject using VICON and xsens:

   1. To design a research project, it is important to identify the research question, the objective, the population, and the methodology to be used. In this case, the research question might be, "What effect does an ankle immobilizer have on the gait pattern of a subject?" The objective could be to compare the gait patterns of a subject with and without the ankle immobilizer. The population could be individuals who have an ankle injury. The methodology could involve collecting data using both VICON and xsens systems, analyzing the data, and comparing the results.

2. Be able to list examples of what motion capture systems are used for:

   1. Motion capture systems are used in various fields, including sports science, animation, robotics, and medical research. Examples of what motion capture systems are used for include analyzing gait patterns, assessing athletic performance, creating animated characters, improving prosthetic devices, and studying the biomechanics of human movement.

3. Be able to list the important subject measurements required for motion analysis:

   1. Some important subject measurements required for motion analysis include height, weight, body mass index (BMI), limb length, joint range of motion, and muscle strength. These measurements help to establish a baseline for the subject's physical characteristics and can help identify any potential limitations or confounding factors.

4. Be able to explain how the Vicon cameras work and how the xsens sensors work:

   1. The Vicon camera system uses infrared cameras to track the motion of reflective markers placed on the subject's body. The cameras capture the position of the markers in 3D space, which is then used to reconstruct the motion of the subject. The xsens sensor system, on the other hand, uses inertial measurement units (IMUs) to measure the acceleration and angular velocity of the subject's body. These measurements are combined to calculate the subject's orientation and position.

5. Be able to explain why static and dynamic calibrations are performed:

   1. Static and dynamic calibrations are performed to ensure that the motion capture system is accurately measuring the subject's motion. Static calibration involves measuring the position of markers or sensors while the subject is stationary, while dynamic calibration involves measuring the motion of the subject during a specific task or activity.

6. Be able to explain why a static trial with the participant is collected when using VICON:

   1. A static trial is collected when using VICON to help establish the position of the markers on the subject's body. This is important because the position of the markers affects the accuracy of the motion capture system. During a static trial, the subject stands in a neutral position while the cameras capture the position of the markers.

7. Be able to explain why a marker/sensor placement system is used:

   1. A marker/sensor placement system is used to ensure that the markers or sensors are placed in the same location on the subject's body for each trial. This is important because the position of the markers or sensors affects the accuracy of the motion capture system. A placement system helps to ensure consistency across trials.

8. Be able to compare and contrast the pros and cons of the VICON and xsens systems:

   1. The VICON system provides high accuracy and precision but requires a controlled environment and a longer setup time. The xsens system, on the other hand, is more portable and can be used in a variety of environments but may have lower accuracy and precision. The choice between systems depends on the specific research question and the requirements