Throughout many calculations in biomechanics – and therefore Visual3d – the Cardan sequence has a significant impact on the results. In this chapter, we explain what a Cardan sequence is, and how it impacts your data when calculating, for example, a joint angle.
The most fundamental relationship between the motion of two segments is the the joint rotation. This motion is described by a 3×3 matrix and is the basis for joint angles.
Many types of calculations in biomechanics involve kinematics in some respect. The motion between two segments is the foundation for many calculations such as joint angles and joint moments. For this reason, it is essential to understand how coordinate systems are defined and how to tweak them to describe exactly what you are trying to measure.
The final segment to discuss is the head. Adding the head to the thorax model, we can define the cervical joint. In this tutorial, we show you how to create a useful landmark at the center of the head in order to create this segment. We also show you some best practices to customize the coordinate system and appearance of the model in Visual3D.
Having already defined the arms in chapter 2 and the thorax in chapter 3 of this unit, we can now cheat a bit to define the shoulder. In this tutorial, we show you how to append a model to another one by adding the arms to the thorax. We also discuss how to reason through small modifications that might be necessary when appending models.
The peculiarity of defining a thorax earned this segment it’s own chapter. Due to the technical definition of proximal and distal, picking targets or landmarks can get confusing. Also, the segment coordinate system will most likely need to be rotated to suit your needs. In this chapter, we focus not only on defining the thorax segment, but also on customizing its appearance in the 3D viewer.
The first joint we expand our modeling skills to include in Visual3D Basics is the elbow. Defining the upper arm is not quite a simple as any of the lower body segments. In this tutorial, we show you how to create landmarks in a variety of ways to have full control of each segment both in the static trial and the dynamic trials. We also employ some key concepts regarding joint coordinate systems.
Visual3D BasicsUnit 8:Working with analog data Chapter 3: Virtual lab basics Coordinate systems are one of the building blocks to […]
Visual3D BasicsUnit 6:How to set up advanced calculations Chapter 6: Euler sequences Simpler motions, typically benefit from the use of […]
Visual3D BasicsUnit 6:How to set up advanced calculations Chapter 5: Cardan sequences Throughout many calculations in biomechanics – and therefore […]
