If you talk long enough with any yoga teacher or massage therapist, they will eventually start talking about fascia. Once they do, most likely they will also talk about anatomy trains – long lines of supposedly “separate” tissues that are invariably connected, even across areas of the body where you wouldn’t expect to find a connection. (Now, fascia is super cool – especially if you are a huge nerd like me. Stay tuned for a fascia-focused post).
The Lower Legs
What is referred to as The Superficial Back Line (SBL) is the first of these interconnect lines referred to in Thomas Myers seminal book, Anatomy Trains. Beginning on the bottom of the toes, (or ending there, if you start from the top – there really is nothing special about starting from the feet, or at least, so says Myers) this uninterrupted line wraps under the bottom of the foot, curves up the back of the heel into the Achilles tendon, then splits into the medial and lateral gastrocnemius – more commonly known as calf muscles.
The Knee Exception
At this point, something unique happens – the calf muscles wrap around the outside of the knee and have their origin in the distal end of the femur (the lowest part of the big thigh bone, closest to the knee). Above the knee, the hamstring muscles (of which there are 3) wrap around the outside of the knee as well, and insert below the knee, to the top of the bones in the lower leg (tibia and fibula). The hamstrings are the next section of the SBL.
The unique thing that occurs here is that the anatomy train can be “derailed” by bending the knee. This is an important concept for yoga teachers. The SBL, while behaving as a single unit when the knees are straight, is disconnected when the knees are bent. The lower legs and feet are removed from the equation because the bend in the knee basically puts slack in the rope of the SBL. This is great because it allows an option for our very tight-hamstringed students to move a little deeper into a forward fold, but bending the knees in while folded changes the stretch to be more focal – it is no longer a full SBL stretch.
Hamstrings and Hips
The hamstrings originate into the ischial tuberosity (your sit bones), then become the sacrotuberous ligament. This is an extremely tough tissue and most of it is physically connected to the pelvic bone – no stretching or sliding allowed. But Myers determined that the topmost fibres of this ligament can actually be lifted off the lower fibres that are sealed to the bones, allowing this tissue to contribute to the SBL. It has a small amount of give and therefore contributes to the train. This ligament basically turns into sacral fascia at the top of the pelvis, near the sacrum (very bottom of the spine).
Now we’re into the top half of the body and we haven’t seen a break in the tissue at all (other than a bent knee, of course). And the top half of the body is even easier to explain, because the long line of paraspinal muscles takes us all the way up through tiny little neck muscles, to the occiput (bottom of the skull – the little bony protrusion at the place where your neck and skull come together). To me, this is the easiest part to picture. The muscles on either side of the spine usually feel a bit like ropes, (especially if you have a chronically tight back like me) making it easy to imagine the connection between the head and the hips.
A Little Aside to Talk about the Neck and Eyes
I’ll pause for a moment here to talk about the little baby neck muscles. Myers pauses to discuss their importance in his book, and I must say I was convinced. So I will do the same. These little muscles which connect the occiput to the first and second vertebra are responsible for generating the “yes” and “no” motions (their science names are rectus capitus posterior major and minor, and obliquus capitus inferior. And there are others, but you can go hunt for them if you’re interested). Moreover, they contribute to head-forward posture. When these muscles are very tight, they will pull the occiput down and shoot the chin a bit forward and up. Many people hold a lot of tension (and pain!) in their necks and these muscles are often partially responsible. I think this is why having a little neck bolster while lying on your back in savasana can be so lovely. If you get the positioning just right, you can get a little traction on these muscles and allow them to gently lengthen while you rest.
A second very cool thing about these muscles is that they are connected to your eye movement! And you can actually feel this if you press your fingers into the area and try to feel the deeper muscles of the neck. If you get this positioning just right and then start making eye movements (looking left and right or making circles) you will feel a subtle firing in these muscles. Super cool! “eye yoga” is practiced by a lot of people, generally thought to increase your eye strength, visual acuity, etc. But perhaps releasing eye tension will also help release deeper neck tension? I can tell you that I am going to start bringing eye movements into all of my neck releasing postures!
The End of the Line
Okay, after that little derailment, back to the SBL. We’re almost done, don’t worry. Basically, after the occiput, the SBL finishes with the fascia of the scalp, finally ending the train at the supraorbital ridge (the brow bone). There is a lot more than just skin on top of your scalp, the fascia underneath the skin has contractile elements (like it does everywhere) and contraction, tension, and binding in the fascia of the scalp can cause headaches. Everyone loves a good scalp massage and this is because we can hold a surprising amount of tension in this sheet of fascial tissue. If you massage your own scalp deeply, you will probably feel the stringy bits and bumps of tense fascia.
That’s it. That’s the SBL. In cadaver dissection, this whole piece can be lifted out of the body as a single unit. Amazing. Or gross, depending on your tolerance for discussing dissection. But what the heck does it do? Why should we care about this?
(This photo comes from Myers book – read it. It’s good.)
The SBL is responsible for holding us upright. Our SBL mediates our posture. Small adhesions, tensions and injuries to the line can cause back pain, hamstring pain or tightness, or poor balance (the body can literally be pulled back on the feet so that most of the body weight is in the heels). A very tight or constricted SBL can lead to increased lumbar lordosis and an anterior pelvic tilt (increased low-back curve – the swayback posture), hyperextension of the knees, plantar faciitis, and bone spurs. Weakness in the SBL can lead to an increased curve in the thoracic spine. Many of us westerners have a fairly weak back line, because of sitting in chairs, well… basically since we were old enough to hold ourselves upright in a chair. This presents itself as the slouching posture. Difficulty sitting upright to meditate for even a few minutes may be a sign of weakness or tightness (or commonly, both) in the SBL.
What Should We Do About It?? Yoga for the SBL
I feel like the postures to help lengthen and strengthen the SBL are pretty straightforward – forward folds with straight legs (so best done from standing. For tight SBLs, seated forward folds are nobody’s friend), plow pose, downward dog, dolphin pose… for those more advanced students several versions of headstand are nice (plus they help us massage that important scalp fascia). Developing strength in the line is equally important, so salabhasana (locust pose), superman pose, warrior 3, and more advanced backbends are all excellent.
I will be posting a video for an SBL length and strength routine shortly, but if you are itching for something to do to start opening your SBL before I have a chance to post, grab yourself a tennis ball and start rolling the underside of your feet. Tension here can lead to tension and pain up the whole line, so give your feet a little extra love today.