• Luke Morgan

Spinal Anatomy

In this article, I'd like to help you understand your back a little bit more, the roles it plays, and the jobs it has.


The spine is one of the most critical and fascinating structures in the human body regarding movement. The spine is a big reason we are able to walk, in fact, if we had just a spine and no limbs, it would still be possible for us to walk on the base of our pelvis, in a similar way to how a snake moves without limbs.

Lower back pain
Lower Back Vertebra

Vertebra

Vertebrae is the name for the bones in your spine. We have a total of 24 movable vertebrae in our back, these are named in subcategories from top to bottom as they have slightly different roles and capabilities. Starting at the top, we have the 7 cervical (neck) vertebra, then we have 12 thoracic vertebrae (mid back), followed by 5 lumbar vertebrae (lower back). We also have two more subcategories that are classed as non-movable joints as they fuse during normal growth and development and they don't have intervertebral discs between them- these are your 5 sacrum vertebra. Finally, at the base of the spine, we have our coccyx which is a fused set of 4 vertebrae and is what is sometimes referred to as your tail bone.

Facet joints

Each vertebra interacts with the surrounding vertebra to create movement (with the exception of the sacrum and coccyx vertebrae) via the facet joints. There are two facet joints at each level of the vertebral column and their job is to stabilise and allow movement of the spine. Each vertebral joint has good forward flexion capabilities, but a limited ability to extend backwards and rotate sideways. This is to protect the intervertebral discs from damage and is also mainly due to the shape of the vertebra. Collectively, when all vertebras move together without muscular tension or restrictions, the spine is capable of large amounts of movement.


Back Pain
Spinous processes visible in the centre of the back

Spinous process

Every vertebra has a spinous process, these are the bony bits we can feel when running our hands down a back and are usually visible when someone tucks themselves forwards to touch their toes from a seated position, the spinous processes provide muscle attachment points to each vertebra.


Transverse process

Every vertebra has a transverse process on either side of it, they serve in a similar way to spinous processes as they provide muscle and ligament attachment sites, but they also articulate with the ribs.


Spinal cord

The spinal cord runs through the vertebral column and is similar to a wire loom in electrics. It encapsulates the nerves that run from our heads to our toes and is responsible for carrying signals from our brain to the rest of our body and vice versa, these signals are responsible for motor and sensory control, i.e. our movement and sensations.




Intervertebral discs

Our cervical, thoracic and lumbar vertebras all have intervertebral discs between them. Each disc's role is to absorb shock, allow movement between each vertebra and transfer forces through the vertebral column. The anatomy of an intervertebral disc is a work of art! With the complexity of its structure and the roles, it is responsible for, it is no wonder disc related pain can be a difficult problem to resolve at times.


Back Pain treatment
Treatment of the Thoracic region

Ligaments

Ligaments are not unique to the spine, they are used to connect our bones to one another to form joints throughout our bodies. Without them, we'd be a bag of floating bones.


Muscles

Like ligaments, muscles are used throughout the whole body. Skeletal muscles provide movement within joints as they are contractile, which means they can be tensed and relaxed. When we are tensed up, our muscles don't tend to respond well, so it's important that our muscles are strong and flexible to achieve the most from our movement.

To Summarise


The spine is made up of a number of different structures, each role is as important as the next. We only get one back, so it makes sense that we look after it throughout our lifetime.


Share this blog post with someone you think could benefit from reading it, and be sure to check out the ZEN Anatomy Instagram page for regular rehabilitation exercise videos, and give it a like whilst you're at it :)


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