One of the keys to preventing knee problems is to build a strong supporting cast around those all too vulnerable knees. That includes the following:
- quadriceps (front thigh)
- hamstrings (rear thigh)
- hip abductors and adductors (inner & outer thigh)
- hip flexors (lifts knee upwards)
Also, a strong core (abdominal, trunk, and low back) area is essential.
One area where individuals get into trouble with knee exercises, especially quad strengthening, is when they have patellar pain syndrome (sometimes called chondromalacia patella), which is an irritation of the kneecap area. Similar problems occur for individuals who have some arthritis in the kneecap region. Strengthening a painful, irritable kneecap can be a real challenge -- where even the best efforts can make things worse from a symptom standpoint.
Most traditional quad strengthening exercises (i.e. leg extensions, lunges, squats, step-ups) will irritate and actually increase symptoms around the kneecap. But building strong quads is important in the treatment of patellar pain issues.
So how do you build the quad without irritating and provoking the kneecap symptoms? The key is strengthening the quads in a way that is both safe and effective for the kneecap. Start with quad isometrics (straight leg lifts) with no weight- concentrating on slowly but firmly tightening the thigh muscle (especially the tear drop muscle just above and to the inner side of the kneecap) to lift the leg (rather than using the hip to lift the leg, a way your body can cheat). Concentrate more on the tightening rather than the lift. When you can do 3 sets of 12-15 reps (holding each rep 5-7 seconds) without difficulty, start gradually adding light ankle weights to these straight leg exercises.
Once the kneecap settles down, and you build some thigh strength, you might be able to try more traditional quad exercises, but watch out for recurrent symptoms, which is quite common with kneecap issues. First try "short-arc" limited range lifts where a small rolled towel is placed under the knee and the limited "leg extension" is done straightening the knee from just shy of straight (i.e. 15-20 degrees) to fully straight. A trainer at the gym also can show you how to "pin-out" the weight stack on a Nautilus or similar machine to accomplish the same thing.
Be patient, building thigh strength with a sore kneecap can take many many months even with the best effort. Also, if pain persists or returns, get things checked out by a sports medicine doc who can prescribe a comprehensive preventive therapy type program for that achy kneecap.