Here is a video of how to perform an inner range quads contraction

Sit with your knee bent over a rolled up towel and tighten up the knee muscles to lift your heel off the ground. Keep your knee firmly down on the roll. Hold for a few seconds, trying to get the heel as high as you can, then relax and repeat. Inner range quads contractions are important in the rehabilitation of the knee. They focus on the VMO (vastus medialis obliquus), which is the control muscle for the patella or “knee cap”. Being able to fire this correctly can prevent knee issues and reduce pain experienced at the anterior knee due to maltracking.