There are also some taping techniques that can help. Use of kinesiotape is great, as it it flexible and still allows the patella to move, but at the same time restricts it some. Any competent PT can help with this. Quads sets are helpful, but not really going to get a lot of strength by doing isometric exercise unless you are really weak. Might help with the sequencing of the muscle contraction though. Short arc quad contraction can help isolate vmo. Typical would be to use a coffee can, or rolled up pillow/towel to the approximate size of the coffee can. Able to add ankle weights and build strength this way.