A comparison of the proximal and distal parts of the vastus medialis muscle.

The vastus medialis muscle has two distinct parts with different fibre orientations and specific functions: the vastus medialis longus (VML) and the vastus medialis oblique/obliquus (VMO). A fascial plane dividing the two parts, and separate nerve branches supplying each muscle part have been reported. This study was designed to verify this. In 50 cadavers, the angular orientations of the VML and VMO fibres with the femoral axis were measured and found to be significantly different (t(49)=36.35; p<0.001). The VML and VMO were both shown to be innervated by femoral nerve branches. A fascial plane between the VML and VMO was demonstrated in one specimen only. In conclusion, the VML and VMO make up the vastus medialis muscle, a single muscle.