The knee is the largest and one of the most complex joints in the body. It is essential for movement, and enabling your legs to bend and straighten. The knee joint is composed of four ligament groups that it depends on for stability: the anterior cruciate ligament or ACL, the posterior cruciate ligament or PCL, the medial collateral ligament or MCL and the lateral collateral ligament or LCL. The MCL and ACL are more susceptible to injury, and individuals that play football, soccer, or twist and pivot their body rapidly while running are at greater risk of damaging these ligaments. Strengthening these ligaments through exercises reduces your injury potential, and promotes flexibility and range of motion in your knee.
Heel Slide
The MCL is located on the inside of your knee, stabilizing the knee joint against unusual movement, and controlling sideways movement in your knee. The MCL can tear or become injured as a result of a direct blow to the outside of your knee while your foot is planted on the ground. Your therapist may recommend this stretch after an MCL injury to help strengthen the ligament, and promote flexion and range of motion in your knee. Begin by lying supine on a flat surface with both legs extended forward. Ensuring that the heel of your foot remains in contact with the floor, slide your heel backward by bending your knee. Continue bending your knee and sliding your foot backward until you feel a stretch in the front your knees. Hold this position for five seconds and slowly slide you heel forward to the starting position. Perform one set of 20 repetitions, three times a day to regain mobility and strength in your knees.
Quadriceps Stretch
This exercise stretches your quadriceps muscles and MCL, increasing flexibility and range of motion, and reducing stress on your knee joint. Stand upright behind a chair, and hold onto the back of the chair for balance. Ensuring both knees are close together, grab your right foot with your right hand, and bring your heel closer to your body, or behind your buttocks. Hold this position for 30 seconds, and return your right foot the starting position. Perform one set of 10 repetitions, twice daily on both legs.
Standing Wall Slide
The ACL is located in the middle of your knee and prevents the tibia from moving out in front of your femur. This ligament provides rotational stability to the knee, and controls the sliding motion and pivoting of the knee. The ACL can tear or become overstretch by a sudden twist or directional change while running, jumping or pivoting. This ligament can also tear from overstretching, but most commonly in contact sports such as basketball and football. Complications associated with an ACL tear include knee joint instability, loss of mobility and inability to extend your legs. This stretch lengthens your ACL and surrounding muscles, promoting flexibility, stability and range of motion in your knees. Stand upright with your back against a wall, and your feet 6 to 8 inches away from the wall. Place both hands against the wall and slowly lower yourself by bending your knees. Continue this downward movement until you are no longer able to bend your knees. Hold this position for 10 seconds, and slowly straighten your knees and return to the starting position. Perform one set of 10 repetitions once daily.
Iliotibial Band Stretch
Begin by sitting upright and extending both legs forward. Bend your right knee and cross that your right leg over your opposite leg. Twist at your waist away from your right leg, and slowly pull your right leg across your chest. Hold this position for 10 seconds and relax. Perform one set of 10 repetitions three times a day on both legs to strengthen your knee ligaments and maintain flexibility and pain-free range of motion.

Information courtesy of Cole’s therapy & injury clinic