Knee strengthening yoga exercises lying down on belly

Lie down straight on your belly. Bring the palms facing down near the shoulders. Take a few normal breaths and relax. 

Stretch your body with toes facing outward.

Bend your legs and bring the feet close to your buttocks.

Lift the stretched legs alternately.

Lift the legs alternately stretched straight back and swing to right and left. 

Do the exercises several times.

Relax in child pose on the belly.

The results are not going to turn out over night. Do it with patience and gain the results.