A tibial prosthesis, and, particularly, a fixed bearing tibial prosthesis has a two-pronged securement mechanism. The training system includes a method of training an athlete to use an article of footwear with a traction system to help enhance speed and agility. The second possible adjustment can facilitate rotating a visible portion of the fixture, typically an aperture or hole through which light transmits from the light source into a room or some other illuminated space. The general noise-whitened samples are filtered with a bank of data dependent noise whitening filters to generate data dependent noise whitened samples, and a data sequence is detected from the data dependent noise whitened samples.