Optical Marker-Tracking in Sports

For many applications in sports the recording of body movement both in time and space is essential for an assessment of physical performance and its optimization during training. The aim of our project is the design of an inexpensive system for 2D - and 3D – marker tracking based on camera systems.

While the equipment relies on standard CCD cameras, the mathematical retrieval of marker coordinates requires computational demanding algorithms of image processing. Our current system acquires images with two cameras at 200 Hz with active markers of different colours.

An example of recorded images and calculated positions both in x- and y-direction is shown below, where different markers are used to register the movements of a volunteer’s foot and knee.

The final goal is a full description of the energy during exercise like running, with:

• mechanical energy as calculated from a body model with velocity and acceleration data,
• systemic body energy consumption as assessed by spirometry, and
• muscle metabolism as given by optical spectroscopy.