For complete development of your quads (the front your legs) you should use a variety of exercises targeting different parts.
The Vastus Medialis (VMO) needs special focus as is the most important portion of the quadriceps group of muscles. This is the teardrop-like muscle on the inside of your thigh, beside your knee. In bodybuilding it is very important for aesthetic purposes but it’s also critical for performance and injury prevention.
This video is one of the exercises to target the area:
Leg Extension with feet out:
- Sit with your legs hip distance apart and rotate your knees outward with feet pointing 45 degrees out.
- Squeeze quads and extend the legs, pause at the top.
- Slowly lower down and repeat.