It really depends on what may be causing your knee pain. It could be because you're a "knee squatter," where you bend only from the ankle and knee when you squat and not at the ankle, knee, and hip. It could be that when you squat your knees are not tracking over you toes properly and instead are moving inward, or together, which places stress on your knees. It could be that the muscles in your thighs and hips are simply weak which is putting more stress on your knees. A good assessment by a health and fitness professional will be key in determining exactly what is causing the problem. You can then develop a plan to correct the issues causing the pain. As a general recommendation, try the following techniques prior to your workout to help improve lower-extremity flexibility, range of motion, and control. First, foam roll your calves, the outside of your thigh (IT-band), and the inside of your thigh (adductors). Foam rolling is a self-massage technique to used loosen the muscles that attach to the knee and help improve knee range of motion. Hold each tender spot for 30 seconds. Next, statically stretch your calves and the inside of your thigh. These stretches, along with the foam rolling exercises, will help improve the range of motion of your ankles and knee, taking stress off the knee joint. Hold each stretch for 30 seconds. Next, perform a strengthening exercise for the side of your hips (gluteus medius). This muscle is often weak and can lead to poor control of your thigh and knee. A simple exercise to strengthen this muscle is lateral tube walking. Perform 1-3 sets of 10-15 repetitions of this exercise. Lastly, perform a ball squat to improve your overall lower-body control. This exercise will help you learn proper squatting mechanics (bending at the ankle, knee, and hip) and will help take a lot of pressure off of your knee. Perform 1-3 sets of 10-15 repetitions of the ball squat.