In contrast to previous investigations, the present study traced all components of the extensor apparatus from the origin to insertion (Figs. 1 and 3). This enabled us to outline the different layers over the whole expansion of the muscle components. The architecture of the quadriceps tendon based on cross- and longitudinal transections (Waligora et al. 2009; Zeiss et al. 1992) is limited and makes an interpretation difficult or even impossible.