The spine is complex and is one of the most important components in the body. I think it is important for everyone to have some understanding of its anatomy so that they can make appropriate decisions about treatment if they suffer from back pain, or want to maintain a healthy spine.
The spine is made up of 33 individual bones (vertebrae) stacked on top of each other in 5 areas:
Cervical Spine – consists of 7 vertebrae C1 – C7. C1 is the atlas vertebra; your skull sits on top of this. C2 is the axis vertebra.C3 – C7 comprise the neck.- Thoracic Spine – has 12 vertebrae known as T1 – T12 and forms your upper and middle back.
- Lumbar Spine – consists of 5 vertebrae, L1 – L5.
- Sacral Spine – consists of 5 fused vertebrae, usually referred to as
the sacrum. - Coccygeal Spine – has four fused vertebrae and forms the very bottomsection of your spine.
Curves
When viewed from the side the spine has curves – these are the arches of your spine. In the same way as arches in architecture allow stress to be distributed, so too do the arches of your spine. In fact, all of our bones are curved for the same reason. The spine has 4 curves, forming a double S, with the curves of the neck and lumbar moving in opposite directions.
A healthy spine, possessing all its normal curves, acts like a spring. Every time you increase the pressure on your body, the spine changes shape just like a spring. The muscles, ligaments (bands of flexible, fibrous connective tissue attaching bones to each other) and fascia act like the guy wires on an antenna, supporting the curved column to reduce stress on the discs and vertebrae.
Discs
Each vertebral bone is separated from its neighbour by a disc. Together, the discs allow movement, absorb impact and cushion shocks.
A disc consist of two parts; the inner area, the nucleus, consists of a gelatinous material. The outer ring, or annulus, is made up of layers of fibre and is the strongest portion of the disc; it keeps the annulus from leaking out, supports the weight of the spine and prevents excessive motion.
Vertebrae
Each vertebra has an anterior (front) part and a posterior (back) part. The front part is called the vertebral body and provides the surfaces against which the discs rest. Two pedicles (struts) of bone project posteriorly from the body and support an arch called the vertebral lamina. This arch over the body of each vertebra forms the canal through which the spinal cord passes. Behind each of the discs and between every pair of vertebrae is a foramen or hole. One spinal nerve root exits from each of these holes. The posterior parts of the vertebral bones are connected by small joints called facet joints. Behind the facet joints, along the midline are spinous processes, these are the bumps which can easily be felt along the back of the neck, thoracic spine and lower back. The two vertebrae at the top of the spine, C1 and C2, don’t conform to this arrangement and will be discussed in another blog.
What is the neutral spine?
If the spine needs its curves, how much curvature is too much or too little? I believe everybody has their own neutral – the position in which their spine is most relaxed and free of the tension. However, poor posture can feel pretty relaxed, so you need to pay attention to your joints and fascia as well as sensing whether your muscles are relaxed.
What is Good Posture?
I prefer to speak about “functional” posture as opposed to “good or ideal” posture. Posture is not a static state. Your body is designed to move, therefore posture needs to be dynamic and suited to you, the individual. Your posture should vary depending on your unique biology, how you’ve used your body, the time of day and what you are doing. If this sounds like I’m evading the question, it is because there is no “one good posture fits all’ concept. Good posture for you, may be bad for somebody else. Movement is the salve for your body, so sometimes it is OK to slouch for a bit, allowing some flexion in your spine, if you’ve been sitting upright for some time.
In the studio, I encourage all of you to develop your body awareness, so that you can learn to feel and recognise when you have achieved functional posture. This involves being aware of:
- your environment – for example the nature of the ground you are standing or walking on.
- your sensory system – eyes and ears.
- your proprioception – what feedback is your body giving you regarding the position of your joints and their tension? Are you moving or stationary?
- your musculature – what is active, what is relaxed?
- your nervous system – for control, and perception as well as memory.
If this sounds like a lot to be aware of and work on, it is an acknowledgement that changing your posture is difficult, requiring a lot of training and time.
What does Stable Mean?
Stability, when we are talking about joints, refers to their ability to resist changes arising from the application of force and even to accommodate excessive forces generated by movement. Under compression, joints stiffen and muscles stabilise a joint through co-contraction, usually activating before stress is applied to the joint. Stability, like posture is not static, we require dynamic stability because we are always moving. This requires good neuromuscular control, which is why we work on it in every exercise.
What Should You do to Maintain a Heathy Spine?
Overall wellness is key to maintaining spine health or living with a spine condition. Key factors:
- A Balanced Diet – being overweight puts extra stress on the spine and can cause back pain. If you are injured, your recovery may be slower. Your spine, like all the tissues in your body, needs nutrients to repair and maintain health.
- Appropriate Exercise – exercise that promotes and maintains normal rage of motion, plus stretching regularly helps avoid putting pressure on nerves.
- Physical Activity – movement really is medicine when it comes to your spine. Avoid sitting or standing in the same position for long periods.
- Restful Sleep – your spine dehydrates over the course of the day. Restful sleep allows your intervertebral discs in your spine to rehydrate. Postural muscles are always switched on, sleep allows them to relax.
- Ergonomics – poor posture increases stress and load on the spine. In class, we are always working on posture and alignment, however, away from the studio sitting mindfully in an ergonomic chair, lifting correctly and avoiding twisting when your spine is flexed can help you avoid back and neck pain.
- Massage Therapy – helps your body relax and increases blood circulation. It helps speed healing if you are injured and improves tissue quality.
- Positive Lifestyle Choices – stop smoking and reduce alcohol consumption.
