I am looking for leg exercises for people who have "knock knees."
Genu valgum or “knock knees” can be both structural and developmental. Both forms are associated with patello-femoral tracking issues and knee pain. The “Q” angle is negatively affected as the patella sits lateral in the patellar groove, and there is increased loading to the medial aspect of the knee joint itself.
Those that are structural result from the congenital development of the neck of the femur relative to the shaft. This creates a more medial angle of the femur as it descends toward the knee.
Developmental knock-knees are usually associated with weakness of all three glutes and their inability to eccentrically control adduction and internal rotation of the hip joint when loaded. Included in this scenario is usually a tight iliotibial band (IT band) and tight hip adductors.
Knock-knees are often only seen as a frontal plane issue. But there are also critical transverse plane and sagittal plane components to it at both the hips and the lumbo-pelvic complex.
Genu valgum statically will reflect hip adduction and internal rotation. Dynamically, such as in gait, it will also reflect increased subtalar pronation, decreased hip extension with increased lumbar extension and increased rotation of the pelvis in the transverse plane affecting both the swing leg and the stance leg.
In your question, you simply ask for exercises for people that have knocked knees. And there are several ways to address such a broad question. However, the first point to make is that some valgus stress on the knee is normal and actually serves a purpose. Just like subtalar pronation, it is a normal movement in function when it occurs at the right time and to the right degree. Both of these motions have gotten a bad label because we typically associate them with too much.
Second, if the valgus knee position is structural, there are limitations to if and how much you can positively influence it. Perhaps one approach to use in your decision making process is consider what exercises/movements do you need to stay away from to avoid feeding the dysfunction. The body will take the path of least resistance. Left up to its own resources, the body will continue to carve out a “rut” in the direction of more and more valgus stress because that is what is familiar.
Corrective and motor learning exercises can be done on the floor and/or with the client sitting. These would be exercises that facilitate engagement of the glutes and abductors and promote hip abduction with external rotation. Restoring functional length to the hip flexors should be priority, as should training the obliques in the transverse plane (see my DVD titled Corrective Exercises for Powerful Change for more specifics). Many clients respond well to myofascial release with the foam roller on the IT band. Or maybe I should say physiologically they respond well because psychologically they may want to kill you after the experience.
Increasing functional demand by getting the person on his or her feet should incorporate exercises that challenge the glute maximus to control internal hip rotation forces eccentrically. The gluteus medius should be trained to control hip adduction forces eccentrically. The posterior oblique system (latissimus dorsi linked with the opposite gluteus maximus) should be challenged concentrically, and the anterior oblique system (external oblique linked with the internal oblique and hip adductors on the opposite side) should be trained eccentrically. These address the reciprocal motion of the trunk on the pelvis that is part of the knock-knee equation.
A couple of examples of more advanced multi-joint, multi-planer exercises that address the areas discussed can be found in the PTN Exercise Library:
Hope this helps. Best of luck.