Yoga and Knee Pain | Prevent Knee Injury in Yoga
Practice yoga to heal your body, not to injure it! Yoga and knee pain do not go together! Many people that practice yoga have underlying knee injuries and many others simply begin to practice yoga and knee pain arises. A basic understanding of the anatomy of your knee and a couple of simple tips to practice on your mat can help you prevent injury and avoid knee pain in your practice.
A common misunderstanding of the knee is that it is only made to bend and straighten. Knee flexion (bending) and extension (straightening) are the larger and more obvious movements of your knee. Your knee also rotates. Yes! It rotates. The knee is not a hinge joint as it is often mistaken to be. Your tibia (shin bone) and femur (long thigh bone) rotate on each other. Rotation of the knee is essential for a healthy knee during many activities and yoga postures. It is, however, essential that you know the limitations of your knee rotation to prevent injury. Most knee injuries in yoga result from over rotating the knee in an attempt to deepen a variety of postures. Some common poses that cause over rotation of the hip are lotus pose and pigeon.
Your knee joint is made primarily of three bones: the femur (long thigh bone), tibia (shin bone), and the patella (knee cap). Your femur and tibia move forwards and backwards on each other causing the knee to bend and straighten. These motions are respectively referred to as flexion and extension of the knee.
Image B to the right demonstrates that your femur and tibia rotate on each other in the horizontal plane. When your tibia is fixed (i.e. in standing), your femur can rotate on the tibia. It may move internally (towards the center of your body) or externally (away from the center of your body). When your femur is fixed (i.e. while sitting on a chair), your tibia can rotate either internally or externally.
When your knee is straight, your femur and tibia are stacked on each other and the joint surfaces are congruent. When your knee is flexed (bent), there is more space available in your knee joint. Therefore, there is a greater amount of rotation available when your knee is bent. You may be able to observe this rotation while sitting in a chair with your knee bent at ninety degrees and your foot unsupported. Place your hands just below the knee and move your foot in and out. Do you feel your tibia (shine bone) rotating? Knee rotation also occurs when you straighten your knee and "lock it out". In order to observe this, straighten your knee almost fully without "locking it out". Observe the exact direction that your toes are pointing. Then "lock out" your knee and observe the new direction your toes have taken. Are they now pointing slightly away from your body? They likely are as a result of the tibia rotating externally on the femur.
Many yoga postures require your knees to rotate. Given that rotation is a natural part of the kinematics of the knee, it is safe to allow the knees to rotate. However, it is very unsafe to rotate the knee beyond its available limits. As a rule of thumb, if you feel knee pain with yoga postures, change the way you practice the posture.
Consider what happens with your knees and hips in Padmasana (Lotus Pose). In order to bring your feet up onto your thighs, it is essential to have a significant amount of external rotation in your hips. That is, your hips must be able to rotate open so that your outer thighs and knees come close to the floor. If your outer thighs and knees are supported on the floor or at least very close to the floor, your knees are in a position to safely bring your feet on top of the thighs without forcing exces rotation in your knee.
The yogini on the left has access to significant external rotation in her hips. Her thigh and knee are close to the ground and she comes into lotus pose without forcing excess rotation in her knees. The yogini below on the right has limited access to external rotation in her hips and therefore her knees are elevated from the ground. To keep her knees safe, she is best to stay in a cross legged position rather than forcing lotus pose. How do you know if you are forcing too much rotation at your knee? Feel for any tension in your knee. When your knee is flexed, the only muscles being stretched are the quadriceps. If you feel a stretching sensation or some tension just above the center of your knee, you are likely stretching your quadriceps. Provided this is not painful, it is safe. However, if you feel tension on either side of your knee or deep in the center of your knee, you are likely stretching your ligaments. The role of ligaments is to hold bones together. There are several
ligaments in your knee that hold the femur and tibia together. In an attempt to come into lotus pose, it is relatively common to feel tension on the outside of the knee where the lateral collateral ligament is (see image B Knee Rotation above). Continuing to push into this tension may cause damage to your lateral collateral ligament or other ligaments of your knee. Ligaments are much different from muscles and stretching them beyond their limits leaves them weak and may lead to long term knee problems.
Eka Pada Rajakapotasana (Pigeon) requires significant opening in the hip and some rotation at the knee. This posture is often described as a "hip opener" and is very useful in increasing external rotation of the hip. However, if you move into this posture beyond your limits of hip external rotation, your knee ligaments are at risk for injury. As described above, if you feel tension on either side of your knee or deep inside your knee, there is risk for injury and the pose needs to be modified so that your ligaments are not over-stressed. A simple modification is to bring your front heel closer to the groin. This may not fully relieve the tension. Unless there is a lot of external rotation in your front hip, your hips will remain up away from the floor. In order to get your knee on the ground, your knee rotates to compensate. This should be avoided. A more supportive modification is recommended. Bring your front hip down onto the ground. As your hips open you can gradually begin to center the hips. For example, when your left leg is in front, you rest the outside of your left hip and thigh on the floor and gradually send your right hip back down towards the floor. With time, your left hip will open into more external rotation and you may be able bring your left hip back up so that both hips are centered.
While teaching pigeon, many yoga teachers instruct students to activate the front foot and pull the toes back so that the ankle is in a neutral position. This helps protect the knee from excessive rotation as it causes the lower leg muscles to activate. Many of these lower leg muscles attach on the outside of your knee. If activated, they will support your knee and limit the excessive rotation that may cause damage to the ligaments.
The knees are among the joints with the highest risk for osteoarthritis. While there is a genetic component to this disease, it is commonly caused by wear and tear on the knee joints. Remember, yoga and knee pain need not go together. Being mindful of the position of your knees is not only important to prevent an injury or knee pain, but also to maintain healthy alignment of your knees for the long run. By keeping your ligaments stable and your knee in neutral alignment, stress on your knee is limited. As with most things, limiting stress on the knee joint, will allow the knee to live a longer, healthier life. You have many reasons for your commitment to your yoga practice, and a healthy body is likely one of them. Throughout your practice be mindful of your knees. If you feel any tension on the sides of or deep in the knees, back out of the pose and find a modification. Remember that tight hips may put you at increased risk for knee injury. Continue to open your hips to protect your knees, and be sure to protect your knees while opening your hips! Rotation of the knee is normal, natural, and required for a safe yoga practice. The same cannot be said for excessive rotation of the knees.
Trish Corley is a Baptiste certified yoga teacher and a licensed doctor of physical therapy.
Trish leads several Baptiste inspired and anatomy related workshops and yoga teacher trainings.
Keywords: yoga and knee pain