In most yoga classes, you’ll often (hopefully!) hear cues meant to help protect your knees. For example, Angle the knee no more than 90 degrees, or, If you feel pain in your knees, back off. And perhaps one of the most popular: Strengthen your quadriceps to lift your kneecaps. Cues like these are crucial, as injuries and pain originating in the patella, or kneecap, can be quite common—and quite slow to heal.
However, what these cues don’t address is the importance of the core, hip abductors (outer hips), and glute muscles when it comes to knee health. That’s because traditionally, treatment for pain in the front of the knee focused on strengthening the innermost quadriceps muscle, called the vastus medialis oblique, or VMO. It was thought that when the VMO was weak, the patella was more likely to drift out of alignment, ultimately causing issues. Interestingly, new findings published in the Archives of Physical Medicine and Rehabilitation and theJournal of Athletic Trainingshow that strengthening the core, hip abductors, and glutes—in addition to stretching the quads—is actually much more effective at easing knee pain than solely strengthening the VMO.
To understand how these muscles affect the knee joint, it’s helpful to think of the knee in the context of the entire leg and pelvis. The patella is a mobile bone structure between the foot and the pelvis; any wobble that travels up from the foot or down from the pelvis affects the patella. While instability in the foot or ankle can contribute to knee pain and dysfunction, it’s a less likely culprit than instability in the pelvis—which is where a strong core, hip abductors, and glutes come into play.
These three muscle groups all surround the pelvic bowl, which means the stronger and stabler they are, the stabler the pelvis will be. This is important, because the orientation of the femur (thighbone) at the hip joint causes a small degree of normal rotation at the knee joint during flexion and extension. However, any pelvic instability caused by imbalances in the core, hip abductors, and/or glute muscles creates pressure that travels to the knee, leading to abnormal wear and tear that can potentially cause chronic pain. For example, internally rotated femurs create a knock-kneed position, called valgus, an angle that’s frequently associated with anterior knee pain. Strengthening the hip extensors, which externally rotate the femurs, helps to counterbalance this pain-inducing angle.
Of course, focusing on the muscles that provide pelvic stability alone isn’t enough; the quadriceps are still important for healthy knees. You must couple strengthening the VMO—that innermost quad muscle—with improving flexibility in the quads, in particular the rectus femoris, which crosses the hip and the patella. When this quad muscle is tight, as is common with most people, it can inhibit kneecap mobility and prohibit proper kneecap alignment, leading to abnormally high pressure where the patella connects to the femur. But when you keep that muscle flexible, the kneecap is free to move as it should.
The poses and cues below will go a long way toward helping you stabilize your pelvis by strengthening your core, outer hips, and glutes, as well as by releasing tension from the quadriceps. The result? Happy, healthy, pain-free knees.