Hamstring injuries are incredibly common to yoga students and especially yoga teachers. Often the problem comes from the repetitive nature of yoga practices, especially Surya Namaskar (Sun Salutations) in Ashtanga and Vinyasa Flow styles of yoga. These movements are not “natural” in that if we were to pick up something off the floor we do a combination of bending knees, leaning and twisting. But since they are a huge part of yoga practice, it important to look at them.
The question of hamstring injuries was recently posted to a forum for UK Yoga Teachers. Since I only wrote an abbreviated response, here is a longer one:
As yoga teachers, often when we think we are hinging at the hip joint, we are actually extending the spine (back-bending) and jutting the sitting bones backwards. This is a kind of swan dive movement. When we do this, the flexion (forward bend) moves out of the back (because now it is in extension) and so all of the flexion of the bend of the whole body is happening at the insertion of the hamstring. It can happen as well in the “look forward” movement in Surya Namaskar. This is especially true in the transitions from Tadasana / Urdhva Hastasana to Uttanasana (arms up to standing forward bend), because at the midpoint of the fold, the weight of the head is very far away from the legs (centre of gravity), making the head very heavy with a huge load on the hamstring insertion. This is potentially dangerous.
When my hamstrings were really painful, I worked with an Iyengar teacher to find new options for my forward bends. In sitting forward bends, we put a belt around the hips, like a seat belt, so that the sitting bones had to stay on the floor. Then I folded forward. This is folding (flexing) from the spine, which is not for everyone. For me, it did allow my hamstrings to heal, because now the flexion was happening in the spine, instead of the hamstrings. However, this is a remedial instruction for people with hamstring injuries only. It is definitely NOT for people with disc injuries or other back pain as it does load the discs.
Now, I try to share the flexion through the whole back body. So the spine is allowed to flex as well as the hamstrings. I try to share the load equally through the whole chain. The first thing to learn here is how to hip hinge.
Finding the hip joint is the first step.
Put the heel of your hand on your “hip bone” or ASIS (the bone that sticks forward if you “put your hands on your hips”). Put your fingers on the pubic bone (the bone that you find if you trace down from your belly button). Where you fingers end, about halfway between those two bony landmarks, is approximately where your hip joint is, deep inside the body.
Put your hands on those two points and practice simple folds. You can do that with bent or straight knees. Your spine shouldn’t need to bend if you are moving maybe 20 degrees forward from straight. You can also flex the hip joint by picking up one leg.
Once you have felt this hinging at the hip joint, it is helpful to explore the pelvis and feel what else happens when you do that movement.
Do this one side at a time. Keep one hand on the hip joint landmark that we found above (usually the opposite hand to the leg is best here). Then feel different landmarks of the pelvis with the other. Go back to the ASIS. It should come forward. Feel around the side, and you might feel your greater trocanter, which sticks out to the side. This is part of the femur or thigh bone. If you go even more towards the back under the buttocks, you will find your sit bone (seat bone / ischial tuberosity). Don’t be afraid to find it. Feel how it moves back when you hinge forward.
The hip joint is a ball and socket joint. So what happens in this hinge is that the socket (pelvis) is rolling over the ball, heads of the femur bones. It should feel quite effortless.
I found this easier to learn coming up from standing forward bend. From uttanasana, put your hands on your sit bones and pull them down (if you have a close friend they can help but it is full on hands on bum…). What you should feel is that the whole torso kind of pops up as a unit. In down dog, don’t let your sitting bones go up and wide (that movement is like exposing yourself backwards). Do the opposite. If you keep the sitting bones connected down towards the heels. It isn’t possible for the sit bones not to move at all, but we don’t want ALL of the fold concentrated in this spot.
If you get a chance, look up John Scott Ashtanga primary series on YouTube. When he does the forward bend of surya namaskar, he almost bends his knees, and he keeps his head very close to the midline of his body. this puts so much less strain on the hamstrings. There are lots of ways to think about it, you might just have to play, and let ANY pain be your guide that something isn’t right.