Yoga And Knee Pain
Trish Corley 
Knee pain is common in yoga practice and can be avoided! Dr. Trish Corley explains the basic functional anatomy of the knee and practical applications
Knee Pain in Yoga: Prevent Injuries and Keep Your Knees Healthy
Dr. Trish Corley is a licensed physical therapist, globally recognized yoga teacher, and a functional anatomy expert. She offers yoga lessons, physical therapy sessions, and courses and trainings focused on healing the body and living the path of wellness.
You practice yoga to heal your body, not to injure it! Yoga and knee pain should 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 yoga.
Basic Anatomy of the Knee
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 true hinge joint as it is often mistaken to be. Your tibia (shin bone) and femur (long thigh bone) rotate on each other and therefore it is more accurate to call the knee a modified hinge joint. 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 and are the "hinging" motions of the knee.
Rotation in the Knee Joint
Image B 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 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 Posture). 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 excess rotation in your knee.
The person in the photo above has access to significant external rotation in her hips. Their thighs and knees are close to the ground and they come into lotus pose without forcing excess rotation in the knees. The person in the photo below has limited access to external rotation in her their hips and therefore their knees are elevated from the ground. To keep their knees safe, it is best to stay in a cross legged position rather than forcing lotus posture. 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 should be 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 posture, 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.
Pigeon Posture - Keep Your Knees Healthy
Eka Pada Rajakapotasana (Pigeon posture) also requires significant opening in the front 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 posture needs to be modified so that your ligaments are not over-stressed. 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.
Choose a Modified Pigeon
1. Bend your front knee:
A simple modification is to bring your front heel closer to the groin/bend your knee more. (It is not necessary to bring your front shin parallel o the front of your mat). This will decreased the tension in your knee.
2. Rest your hip down:
A more supportive modification may be needed if you still feel pain in your knee. 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.
3. Lie Down
A third option is to lie on your back and practice "reclined figure four". Bend both knee with your feet on the ground. Then cross one leg over your other thigh to create a triangle with your leg. Reach one hand through the triangle and your other hand on the outside of the uncrossed leg. Pull the thigh of the uncrossed leg towards you and you will stretch the outside of that hip. This gives you a similar position in the hips as pigeon posture without the stress on your knees.
Flex Your Feet
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.
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 knees in neutral alignment, stress on your knees is limited. As with most things, limiting stress on the knee joints, will allow the knees 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 yoga practice be mindful of your knees. If you feel any sharp pain or overbearing tension on the sides of or deep in the knees, back out of the posture and find a modification.
Remember that tighter hips may put you at increased risk for knee injury. Continue to stretch and increase the range of motion in your hips to protect your knees, and be sure to protect your knees while mobilizing 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.
Are you experiencing knee pain in your yoga practice, with walking or other sports and functional activities? Work with me to modify your practice and learn key ways to keep you knees safe. A wellness screen or physical therapy session may be just what you need to stop that knee pain and prevent any injuries. Contact Me Today!
-- Dr. Trish Corley, PT , DPT, E-RYT 500
Categories: : Anatomy, Physical Therapy, Yoga