PLUMS & DISCS
A really juicy plum is sweet and full. Prod it with your fingers (palpating it!) and you can feel the give-and-take within the body of the fruit. With that image in mind, imagine your vertebral column, the curvy, almost “slinky-like” chain beginning at the base of the skull and continuing down to your pelvis where the lumbar spine meets the sacrum.
The vertebral column is made up of vertebral bodies, and between each vertebral body is an intervertebral disc (IVD). Think back to that juicy plum, the give-and-take as you gently prod it. The IVD works in a similar fashion by providing cushioning to the vertebrae and acting as a shock absorber. During the day the intervertebral discs sustain the pushing and prodding of the spine as it moves in all directions. As a result of gravity, by day’s end the IVDs have become compressed. There is maximum pressure on the discs when sitting, medium when standing, and the least amount of pressure when lying down. Indeed, after a sound night’s sleep you are a tad taller in the morning because the intervertebral discs have become plump with water and are less compressed.
As for that sweet juicy plum, once you have bitten into it the plum no longer responds the way it did beforehand. Perhaps the flesh of the fruit comes spilling out via drips and small chunks, and maybe you even round your back, jutting your head forward so the yummy mess doesn’t wind up on the front of your shirt! While puncturing the plum is good for your palette, this equivalent action in an intervertebral disc would be counter productive for your spine. Protruded, herniated or prolapsed discs occur when the nucleus of the disc breaks through the area surrounding it, much like your bite into the plum lets the center break through the area surrounding it.
PLUMB LINE (or What are the normal curves of the vertebral column?)
Place a book on your head and try walking without having the book fall off. The walking rhythm with the book staying put is the neutral position of your head in relation to the vertebral column.
To sit or stand with your vertebral column in its normal curvature you first need a sense of what that is within your body. In construction a plumb line is used to determine that something is vertical. In the body a plumb line is a vertical line that you can visualize on the outer side of the body. “It passes through the external auditory meatus of the ear (outer ear), the center of the shoulder joint, the hip joint, the center of the knee joint, and finally the lateral malleolus of the ankle (outer side of the ankle joint).” (From the online course Experiential Anatomy.) The plumb line touches upon body parts that, if vertically aligned, give rise to the normal curvature of the spine.
To find your plumb line ask someone to take a look at you from the side. Stand with your eyes slightly lower than the top of your ears, relax your shoulders, arms loose at your sides, feet and legs supporting your body. If you tend to tuck your tailbone, untuck it. According to Judith Hansen Lasater and Mary Richards in Experiential Anatomy, tucking the tail takes the body out of joint and inhibits the functional muscle patterns that support the core.
Ask your plumb line assistant to tell you what they see. If they note that your head is forward of the plumb line, and if this is not due to a structural issue, it is likely that the jutting of the head is due to sitting with a rounded back. Why might someone have a rounded back while seated? Think: driving, sitting hunched over a computer, looking down at a cell phone…
Sitting with a rounded back impacts the cervical spine and produces a forward jutting head (the head comes forward of the plumb line). When this happens, the weight is no longer being efficiently borne through the vertebral bodies. The result is flexion in the lower cervical (lower part of the neck) and back bending in the upper cervical, neither of which is beneficial to the spine.
POSTURE (adapted from Experiential Anatomy)
Come to your normal standing position. If you feel comfortable, close your eyes a moment and sense your body in vertical space. Reach the crown of your head towards the sky. Sense your normal curves within your vertebral column. If your eyes are closed, open them. These curves are what bear the weight of your body as it responds to gravity. Has anyone ever asked you to “sit up straight” or “stand up straight”? Physiologically it is impossible to straighten your spine because it just isn’t built that way; it is curved, not straight. The only “straight line” in the vertebral column is the line of force – the way gravity is carried through the column.
Now find a chair and sit on it. Not sure of the way to sit for optimal posture? The key to sitting is all in the pelvis! Once seated, roll slightly forward onto the pubic bone, feet comfortable on the floor or on a small stool if the chair seat is too high. The pelvis should be elevated above the level of the thigh bones, creating an approximately 120° angle between the torso and the thighs. (Not only did I learn this in Experiential Anatomy but also from Mary Bond’s Google Talk: The New Rules of Posture: How to Sit, Stand and Walk in the Modern World, where she suggests perching rather than sitting.)
To enjoy your posture as much as you (perhaps) enjoy your plums, work on keeping your posture in synch with your plumb lines, honoring your pelvis (pubic bone tilts forward in sitting, tail bone untucked in standing). And maybe take a yoga class!