The purpose of Yoga poses is to generate physical vitality so one can proceed through life with positive energy flow and with a holistic connection to what brings balance and harmony. Standing Yoga poses offer these benefits when mindfulness and proper intention is applied. Without mindfulness, some standing Yoga poses present a tendency towards knee locks and hyperextension, which can produce chronic problems in the function and health of the knee joint.
What is knee lock?
Knee lock occurs when the knee joint fully extends. When the knee moves into full extension, the femur (thigh bone) slightly rotates inwards (medially) on the tibia (shin or lower leg bone) and ‘locks' the knee joint into this extension phase.
Some people have a greater tendency towards locking the knees as they have joint structures that promote a hyper extended position when the legs straightened. The legs splay backwards almost like a crescent shape. This hyper extended locked knee position tends to generate a passive stance and allows the body weight to transmit heavily into the ligaments, cartilage and posterior connective tissue of the knees. In addition, this hyperextension and internal rotation creates a line of poor body mechanics including the production unwanted anterior pelvic tilt (promoting excessive lordotic spinal positions) and excessive pronation of the foot.
The ‘knee lock' presents some useful function and purpose in allowing one to stand without using the quadriceps to hold the legs in a straight position. This creates an energy-efficient mechanism that allows you to maintain the knee in extension over prolonged periods of standing without requiring muscular contraction.
However, this ability to lock the knee joint can promote a passive approach for some people in their yoga practice and can encourage some people to shift away from progressively engaging muscles to produce therapeutic benefits. Rather than exploring and using the muscles in the lower body to create lift and space, one can fall into this low energy knee lock and into possible hyperextension, thus reducing the benefits of the standing Yoga poses.
How to Move Away from Knee Locks in Standing Yoga Poses?
Once the knee is ‘locked', it must be ‘unlocked' by a small muscle behind the knee joint called the popliteus. The popliteus originates from the middle facet of the lateral femoral condyle and inserts on to the posterior tibia under the tibial condyles, with its tendon traveling into the knee capsule to the posterior lateral meniscus. When the popliteus muscle contracts, it laterally rotates the femur (thigh bone) on the tibia and unlocks the femur from the tibia. Once the knee is unlocked, the knee joint can continue to flex with the aid of other knee flexors like the hamstrings.
To prevent the knee from falling into locked positions and to keep muscular engagement in the lower limbs, consider keeping a slight soft bend in the knees where the popliteus and hamstrings maintain a slight degree of constant ‘play' in the knee joint (the softness in the knee should be very slight as can still allow the leg to move into a large degree of lengthening). The quadriceps will then react and counter this motion creating stability and absorption of sudden shifts in position. This co-activation of anterior and posterior muscles, removes pressure from the knee joint and its' connective tissues. One then remains more present and aware in applying proper healing mechanics in the yoga pose. The co activation of the thigh muscles promotes a purposefully expansion throughout the entire posture by stimulating constant awareness from head to toe.
How to apply co activation in Yoga poses?
Some Yoga poses that demonstrate tendencies for falling into passive knee locks are:
*Mountain Pose (Tadasana)
*Extended Triangle Yoga pose (Utthita Trikonasana)
*Extended Hand-To-Big-Toe Pose (Utthita Hasta Padangustasana)
*Half Moon Pose (Ardha Chandrasana)
*Lord of the Dance Pose (Natarajasana)
*Intense Side Stretch or Egyptian Pose (Parsvottanasana)
*Warrior III Balance Pose
The application of co activation is quite similar in standing Yoga poses. The main adjustments and modifications will occur when the center of gravity or body weight shifts out of the anatomical line of Mountain pose. Mountain pose and Tree pose will require similar sensations and application of co activation keeping the knee from locking. Postures like Lord of the Dance Pose and Parsvottanasana shift body weight forward thus promoting a greater tendency of pushing back into the knee lock. Therefore, the posterior muscles (popliteus and hamstrings) will need to generate a bit more resistance and stabilization.
As you experiment with co activation and knee lock prevention, also observe how you can use the energetic lines of the feet, toe mounts and external hip rotators. Notice how muscles at the proximal and distal ends of the muscle chains assist the overall stability of the standing Yoga pose while supporting the freedom of knee joint. Enjoy how you can integrate co activation and knee lock prevention as an additional means of connecting into your physical practice and becoming more in tune with the benefits that can surface from these standing Yoga poses.
Kreg Weiss is a co-founder of My Yoga Online and certified Hatha Yoga Teacher. Several years ago, Kreg discovered yoga while teaching health and fitness. Yoga dramatically transformed Kreg's approach to teaching health and wellness as well as changed his personal life bringing new direction in finding physical, mental, and spiritual growth.