Our Sitting Posture
Sit up straight! Don’t lean over your plate of food! The request is straight forward, but the ‘doing’ may be something else. How can you change something you’re not even aware you’re doing?
What happens when we sit poorly?
The lower back can lose its natural curve causing a flattening or reverse curve of the lumbar spine.
The chest/rib cage begins to collapse (once again succumbing to the ever-present effects of gravity.
Add to this the head and neck beginning to move too far forward.
The Rib cage attaches to the Thoracic spine. If while sitting poorly the rib cage collapses, by virtue of its attachments the Thoracic spine will also change its position. As the rib cage moves forward and down the thoracic spine will tend to curve more than its design naturally allows.
A funny thing happens when the head and neck follows the chest downwards. Our internal self-correcting system will tilt the head once again in the opposite direction. Can you see how this will create undue stress and strain on the neck and shoulders, as the natural curve of the spine at the neck is challenged to increase its curve excessively?
Our brain in its wisdom to protect and keep us moving forward wants us to look ahead so we can keep a-head.
A study completed by Dolan and Green in 2006, required subjects to:
- Sit in a slouched position for 3 seconds and then find a neutral sitting position for the spine; and then to,
- Sit in a slouched position for 300 seconds and then find a neutral spine
The study found a direct relationship between prolonged periods of sitting in a ‘slouched’ position and a later increased difficulty in finding a comfortable neutral sitting position.
To support this, further studies have found that sitting on chairs that encourage the lower back to round out backwards into a lumbar kyphosis (a movement away from a natural curve may) can have a direct effect on the health and wellbeing of the discs that offer a ‘cushioning’ between the vertebrae (Intervertebral Discs). Potentially leading to a lack of support, stability, and lower back pain.
We therefore need to assess:
- How we sit;
- How long we spend in uninterrupted sitting;
- What measures we have (or should) put into place to get up and move if we ‘must’ sit for extended periods of time;
Dolan, K.J., & Green, A. (2006). Lumbar spine repositioning sense: The effect of a ‘slouched’ posture. Manual Therapy. 11(2006) 202-207.
Kendall, F.P., McCreary, E.K., & Provanc, P.G. (1993). Muscles, testing and function (4th ed). Baltimore, MD: Williams & Wilkins.
Pynt, J., Mackey, M.G., & Higgs, J. (2008). Kyphosed seated postures: Extending concepts of postural health beyond the office