What is hyperextension or locking of the knee joint?
Hyperextending the knee is simply taking the leg beyond straight. In standing poses the leg may bow backwards slightly and in seated asana the heel of that leg may lift off the mat. In a standing position we bear weight using the strength of connective tissue in the knee joint, particularly the anterior cruciate ligament (ACL), and not muscle.
The vast majority of us have the ability to hyperextend our knee joints and we use hyperextension in everyday activities like walking or climbing stairs.
Hyperextension is sometimes referred to as “locking the joint” which causes some confusion because in the medical world this is when the knee joint is completely stuck in one position. Locking is a rotational movement that naturally occurs in the knee joint at the point of full extension. The term lock your joint is commonly used in Bikram Yoga and we will address this a little later.
Nothing is black and white when it comes to alignment cues and human anatomy. There is never one universal cue that works for everyone.
It is also important to mention that no movement that we can naturally make is inherently bad for us, as long as we are moving with intention, the overall health of the related body part is good and there isn’t pain during or after the movement.
Here are some occasions when hyperextending the knee joint might be appropriate:
Ø When you want to intentionally stress the ACL in order to strengthen it. Wolf’s law that states by gently stressing connective tissue we strengthen it while lack of use leads to weakness and atrophy. Obviously too much stress isn’t good for connective tissue either.
Ø When you want to conserve energy. Hyperextending reduces the need for muscular engagement that means less energy expenditure.
Here are some occasions when hyperextending the knee should be avoided:
Ø If you have injured your ACL or are experiencing problems with your knee hyperextension may need to be avoided.
Ø For some of us when the knee is hyperextended more pressure is put on the front, inner aspect of the joint which can begin to damage the cartilage and menisci inside the knee that are there to support and protect the joint.
Ø When you want to build the strength of your leg musculature. Hyperextending the knee joint makes it more difficult to engage the muscles around the joint therefore limiting our ability to increase the strength of our legs.
Ø Hyperextension of the knee may have a knock-on effect to adjacent parts such as hips and ankles causing further misalignment, strain, tension or injury. In this case it should be avoided.
Here are some top tips for preventing hyperextension of your knee joints:
Ø Become more aware of how you stand during your day and start to notice when you might be hyperextending your knee.
Ø By micro-bending your knee just a tiny amount you will create the correct alignment in the joint and start to develop strength and stability.
Ø Develop the inner arches of your feet and try to become more aware of how your are spreading the weight across all four corners of your feet when you are on and off your yoga mat.
Ø Work on developing your Gluteal muscles and releasing tight hip flexors that may be causing you to tilt your pelvis forward therefore hyperextending your knee joints as a result.
Ø In postures such as Extended Triangle Pose energetically draw the feet towards each other while gently lifting the kneecaps. This co-activation will hug the knee joint and prevent hyperextension. I believe that this is what Bikram Yoga teachers are referring to when they cue locking the knee joint.