Knee Safety in Hip Openers


Remember the children’s song: With the leg bone connected to the knee bone and the knee bone connected to the thigh bone. This could be a yoga anthem worth chanting before class. Our bodies function as a whole, and no one action goes without a counter action, reaction, or complementary action in another part of our anatomy. This is especially important to remember when it comes to hip openers, which can unfortunately lead to the non-existent ‘knee opener’ which is yoga code for a painful and long recovery from an injury to our knee.

The knee joint is actually composed of two joints

The femur bone of the thigh as it meets the tibia bone of the shin, and the patella bone of the knee cap as it lies on top of the femur. The patella is held by the tendon of the quadriceps, the main muscle that acts to extend / straighten the knee. If we contract our quadriceps, our knee cap rises.

The femur and tibia are connected by four major ligaments: Two cruciate ligaments (anterior and posterior) and two collateral ligaments (medial and lateral). These ligaments help prevent excessive motion at the knee. There is another important structure at the knee that is unfortunately one of the more common sights of injury in a yoga class – the meniscus. There are two menisci, medial and lateral (inner and outer), which are thin pieces of cartilage that act as spacers in between the femur and tibia, evenly distributing weight at the joint. The meniscus becomes prone to tearing when the knee is in full flexion combined with twisting.

This brings us to the biomechanics of the knee.

The main action of the knee is flexion to extension. It is known as a hinge joint, meaning it hinges open like a door. Try to twist open a door and it rips off its hinges, try to twist at the knee and you leave it vulnerable to injury. There is a slight amount of tibial rotation on the femur between 0 degrees and 20 degrees of flexion, known as the screw home mechanism. This action is so the bones glide on one another as we unlock the knee from extension.

Twisting at the knee is not something we generally try to do in


When it does come into play, however, is in hip openers. If our bodies meet resistance at one joint (limited rotation at the hip), the motion is transferred to the next joint (the knee). Except, we know the knee does not twist. There are no poses in yoga that ‘open’ the knee. You may feel tension at the back of the knee in forward folds (stretching the hamstrings which attach on either side of the knee), maybe some slight tension at the outside of the knee with poses that lengthen the iliotibial band (a band of connective tissue that runs from the knee to the hip), but in hip openers we should never feel sensation in the knee.

In order to achieve hip opening a few things need to occur. First, our femur bone must rotate in the acetabulum (hip socket). This is an aspect that is sometimes overlooked. We all have different shapes to our bones. Some of us have shapes that allow a large freedom of movement in the hips, and others among us will be limited by our bony architecture. No amount of stretching can change the shape of our bones.

The other action that needs to occur is lengthening of our hip rotator muscles (the piriformis and friends, and the gluteus group). The irony of our western lifestyle is that we spend our days sitting in a chair, tightening our hips ,so that we have come to a yoga class to sit and open our hips. This is an aspect we can change with patience, acceptance, and grace. A lot of emotions can be stirred up when we start to open our hips.

Let’s take a closer look at two popular hip openers.

Thread the Needle Pose.

This is a safe and effective hip opener that is accessible to all yogis from beginners to advanced. It also takes out gravity, decreasing the risk of injuring our knees. Have a strap near by as you lie on your back, knees bent feet flat on the floor. Pick up your right leg and cross your ankle just above your left knee on your thigh. Remember the other connecting joint – the ankle. When we dorsi flex the foot (toes towards shin) this places the ankle in neutral and aids alignment at the knee. Allow your right thigh to spiral out, inner thigh moving towards you, outer thigh moving away. If you feel sensations at the knee, back off and allow your body to naturally soften into the pose.

Using your strap or your hands, wrap around the under side of your right thigh, pulling it towards you. Your head should comfortably rest on the mat. Continue to rotate your hip outwards. This is an excellent prep for other hip openers as you are always in control of how much opening is actually happening.

Pigeon Pose / Eka Pada Rajakapotasana.

In this advanced hip opner, we sit with one leg extended behind us, and the front leg folded in front of us, knee slightly wider than our same side hip. Our bony anatomy comes into play here. Our front hip needs to deeply externally rotate which means our femur bone must be a certain shape that it can achieve 45 degrees or more of rotation in the acetabulum. If this rotation is limited by either our bony or muscular anatomy, the motion starts to transfer to the knee.

Just as we did above, dorsi flex your foot to neutralize the ankle and align the knee. Start with your foot close to your pelvis. This placement requires less opening at the hip. As your hips open, you can move the foot further away from your pelvis so that your shin is moving towards perpendicular to the mat. This might take a few lifetimes of practice, so be patient. You should not feel any sensation in your knees. If you do, back off, or slowly remove yourself from the pose. If you have a history of knee pain, or very tight hips, Pigeon pose is not for you. Stick with thread the needle pose.

Yoga can be a wonderful way to strengthen and support our knees. Knowing a little more about our anatomy, and the connections between our different parts can allow us to safely move deeper into our yoga practice with confidence.


Dr. Robin Armstrong

Dr. Robin Armstrong is a chiropractor and yoga teacher in the Kitsilano neighborhood of Vancouver.  Combining her two roles, she has taught yoga anatomy for a number of yoga teacher training programs as well as workshops for yoga teachers to understand how our anatomy affects our yoga practice. She regularly contributes articles about yoga and health and has been published in the Globe and Mail, Vancouver View, Alive Magazine, and as well as writing a regular blog about yoga anatomy and injury avoidance,
Dr. Robin is in private chiropractic practice in a multidisciplinary clinic where she uses traditional Chiropractic, Active Release Technique, and Yoga Therapy to get her patients moving and feeling their best.  In her free time she enjoys practicing Anusara or Iyengar yoga, hiking, traveling and learning more about making green and healthy choices to serve our planet and ourselves.


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