Here's the big news, for some dedicated practitioners, you might never be able to do certain poses like the splits, head/toe back bends or legs behind head. That is not because you lack flexibility or muscular strength. It's because we're running into a problem called skeletal differences.
We're all born with a certain bone structure. We may have slender/round/torsional bone arrangements and that our joints are predisposed with a certain range of motion. Imagine our skeletal blueprint is wrapped with ligaments, tendons, muscle tissue and fascia. With a daily yoga practice, we may stretch and lengthen our muscular tissue and connective tissue so that respectively we become more flexible and mobile.
However, at one point, we will reach a point of bone compresses at another bone. (Also known as 'bone on bone' by Paul Grilley). Just like extending our elbow joint, once the humerus bone hits the forearm (radius and ulnar), we have reached the maximal range of motion at the elbow and movement stops. Depending on the joint or bone structure, some of us can extend at 180º or hyper-extend beyond 180º.
Applying the same concept to our hips, maybe you can go all the way down into the Hanuman splits because the hip joints allow the femur bone to rotate and flex or extend forward and backward. This is based on long and supple hamstrings, so we can eliminate any flexibility issues. Maybe for you, even though your hamstrings are flexible, due to the limitation in the hip joints, at five inches above the ground, your legs cannot open any further and that will be your version of Hanuman splits.
1. How long and how often have you been practicing?
This is crucial because if you practice for the past 10 years but only once a week, chances are you're still working through the muscular tension and haven't quite reach bone on bone. However, if you've been practicing the past three years five to six times per week, you might have reached your maximal range of motion.
2. Do you have any previous injuries?
If you had a previous injury, there might be a lot of scar tissue built up in this area. Scar tissue are tougher and harder to lengthen. For this, you need patience and daily stretching to slowly elongate this area.
3. How do you know you've hit bone compression?
When you reach bone compression, there should be no pain or discomfort. Just like extending the elbow, you simply feel the bones can no longer move-like hitting a wall. One way to test the hip flexion range of motion is by laying on the ground. Bring one knee (keep it bent) towards the chest. At certain point, the knee will reach a resistant edge. If you're unsure, watch the bottom extended leg, if it starts to move slightly, it means that the top leg has reached bone compression. You should be relaxed during this exercise, so it's better to test it with an experienced teacher or practitioner.
4. So what to do if you have early bone compression?
For this, I can only offer you my personal opinion. At certain point, we have to accept and appreciate who and what we are. Putting legs behind head or touching our toes to head in a back bend will not lead us to enlightenment or in the slightest way extend our life span. When I step on the mat, I start to appreciate my physical limitations and work with what I have, from there I develop peace and contentment from within.