Quiz answers are at the bottom of this page.
When the leg is straight, the knee is said to be in extension. When the leg bends at the knee it is said to be in flexion. When the knee goes backward beyond its straight position, it is said to be in hyperextension. Extension and flexion are part of normal, healthy range of motion, but hyperextension can potentially destabilize the knee joint by stressing many of the joint’s ligaments and tendons, especially the anterior cruciate ligament in the front. A destabilized knee joint is more susceptible to an “acute” injury. Chronically hyperextending the knee can lead to an “overuse” injury, or prevent a knee injury of any kind from fully healing. For these reasons hyperextension should be avoided. Even slight hyperextension can continue to aggravate an injury.
All yoga teachers should be able to see and correct excessive hyperextension. Can you detect more-subtle hyperextension? If you can, you will be doing your students a great service to help them prevent hyperextension of their knees. Which one of photos 1 and 2 below shows hyperextension, and in which leg? .
Medial and Lateral Stress
The weight placement and/or position of the foot can either be neutral or stressful to the knee joint. When the weight is too far to the outside of the foot, or the foot is turned in too far relative to the position of the knee the outer (lateral) ligaments of the knee will be stressed. When the weight of the foot is too far to the inside and/or the foot is turned out too far relative to the position of the knee, the inside (medial) ligaments of the knee will be stressed. When ligaments are stressed, joints become less stable and, as with hyperextension, injuries are more likely to occur, and recovery can be hampered or even totally prevented.
In photos 3–5 below, which knee is in a neutral position, which one is being laterally stressed, and which one is being medially stressed?
In Therapeutic Yoga, I teach participants how to detect subtle hyperextension from all viewing angles (such as from the front, not just the side), and even through loose clothing. You’ll also learn to see medial and lateral stresses—and how to teach your students to avoid these stresses in a variety of positions, such as standing poses, bridge pose, forward bends and more.
Getting the alignment right not only makes your students safer and more physically fit (misalignment often occurs from not engaging the appropriate muscles), but also helps them enjoy their practice more, because good alignment feels good. And when you feel good in your yoga practice, the energy goes inward and upward—naturally and joyfully!
See Keeping on Track with Knees for tips on anatomy, prevention of injuries and rehabilitation of knees..
Answers: The left knee in photo #2 is in hyperextension. The knee in photo #3 is being medially stressed, #4 is neutral, and #5 is being laterally stressed