Lunges are especially good for people coming back after a knee injury. Stand with legs shoulder-width apart, making sure your posture is good, and take a dumbell in each hand. Ensuring that your torso is upright, take a large step forward and lunge by bending your rear leg and the leading leg to a comfortable level, then return to the standing position.
Make sure your knee doesn't go past your toe and always stay within your pain threshold - it should never hurt, so start shallow if you're a beginner. In the early stages of rehab, just go up and down without stepping forward. The common mistake is to tip forward at the waist instead of keeping the back straight. The movement needs to be slow and controlled, so that each muscle group is working effectively to control and balance each joint.
