Anatomy Nerd-Out! Understanding your Lumbar Spine.

During our yoga teacher training this past year, one of our teachers-to-be sent us an email asking for clarification about the lower back and forward folding. What exactly is supposed to be happening back there? It’s an interesting subject and Leena has written a delightfully detailed reply. Check it out!

Q: Can you please help me to understand what the safety concern is for not rounding the spine too much in forward folds? Why do yoga teachers often emphasize a lower back curve?

Are we aiming to tilt the pelvis and have the sacrum be the highest point of our body?  What comes to my mind is that we want a even rounding on the spine, but why? Does it provide release for the sacrum? and if so why should we care about this?

A: The vertebra of your spine are designed for movement, and most people don’t move their spines nearly enough. Think of the positions you spend most of your time in: sitting, laying down, walking. None of these positions require much spinal movement. On the other hand, think of a dog running full tilt. Four legged animals use their spine to locomote. One reason yoga is so great for the body and particularly the spine and nervous system is that it helps us awaken, move, and lengthen the spine through flexion (forward bending), extension (back bending), rotation (twisting) and lateral movements.

 A lot of people have low back pain, and stiffness, so let’s break down the alignment of the lower back, or lumbar spine a bit more. The different areas of your spine are each designed for taking a certain strain from different movements and positions.  The lumbar vertebrae form a lordosis, or an inward curve towards the front of the body. Due to their natural position for lordosis, the lumbar vertebrae can only flex (forward bend) to a certain point before there is pinching, tearing and potentially rupture in the soft discs between the vertebra.

Just to give you little more reason to care about this, over the course of my teaching career, I’ve had at least 15-20 students with lumbar disc issues, so it is something quite common in our population.

Disc “herniation”/”slipped disc”/”disc tears” happen most commonly in the lumbar spine when the spine is flexed and then asked to bear weight. This is why you are told to bend your knees when you are lifting heavy stuff. In a lumbar herniation the disk ruptures toward the back of the body the vast majority of the time. A herniation can cause intense pain when a person forward bends, and back bending gently can be therapeutic. Because many people are already lacking proper curvature (lumbar lordosis), to then forward bend with too much flexion in the lumbars can be problematic and exacerbate disc issues causing a potential herniation/rupture, or just cause nerve pain. So in yoga classes, especially for beginners, we focus on re-creating adequate lumbar curve and lengthening the lower back.

 Furthermore, many beginners have a lack of mobility in the hip joint, so when they bend forward, they are bending just from the vertebra in the back, and potentially from a bit of movement of the sacrum, rather than from the ball and socket joint of the hip doing what it’s designed to do. So by being really firm in our instructions about keeping the back straight and long (initiating the forward bend with lumbar curve), we are helping student to increase range of motion in their hips again, and relearn how to move from that joint. 

 When the movement is initiated by bending at the hips and not in the low back, then we get a proper stretch in the glutes, piriformis, and hamstrings, rather than an improper stretch in the low back. We want to stretch the hamstrings and back of hips because in most people those muscles are “locked short” (the muscle fibers are in a perpetual shortened position from sitting) and in many people, especially older adults, the low back muscles are “locked long” and are weak (the muscle fibers are in a perpetual lengthened position from slouching while sitting).

Looking for the juncture of the bottom sacrum/top of the tailbone as the highest point in uttanasana (standing forward bend) is a helpful landmark that shows that the student has accomplished flexion from the hip joint, rather than from the lumbar spine. For a more intermediate student, once the movement is initiated from the thigh bone rolling in the hip joint (flexion of the hip), and hence the sacrum tipping forward (toward the head), then the student can focus on evenly rounding the spine and bringing forehead toward shins. In a position like table pose, flexion of the spine (cat pose) including the low back should be okay because there is way less weight bearing force on the spine.

 Leena Miller Cressman is the director of Queen Street Yoga. Right now she’s in love with practicing the Tensegrity Repair Series, handstands and doing gentle twists over her bolster. You’ll also find her cruising around on her rusty but trusty bike, and tending to her community garden plot full of arugula, kale, and basil.