Mixed

Isometric training at long muscle lengths produces similar quadriceps femoris hypertrophy to full range of motion isotonic training in resistance-trained individuals.

If you want to build quad size, you don't necessarily need to do full squats or leg presses. You can use isometric holds at the bottom of the movement (long muscle length) for 30 seconds per set. Do 3-5 sets per session, twice a week, progressively adding sets over 6 weeks. This will build muscle just as well as traditional dynamic leg exercises, provided you are already trained in resistance training.