Hi, I'm Dr. Aria Yarmand and this is issues effecting knee stability. The knee joint is made of several ligaments which are prone to injury. The stability of the joint is especially effected when twisting and can often be injured during athletic activity. There are four main ligaments that help control the stabilization of the knee the ACL or the anterior cruciate ligament is in the front of the knee. The PCL or the posterior cruciate ligament is behind the knee. The medial collateral ligament or the MCL is on the inside of the knee and the lateral collateral ligament or the LCL is on the outside of the knee. Strengthening your quadricep muscle is the best way to strengthen the knee joint, similar to the way core exercises help strengthen your spine. To exercise your quad muscles, simply extend your legs up and down while being seated in the position such as this. Adding resistance will help increase the strength of the quadricep muscles but do this at your own fitness level. Another exercise to increase the strength in your quadriceps is a simple squat. With your feet shoulder width apart and start bending at the knees slowly with your hands in front of you for balance and then come back up in a similar fashion. Do this exercise repeating it several times and make sure to do it slowly so that it increases the resistance in your legs. If this exercise causes pain in your knees, please stop it immediately.