It's not as simple as its seems - there really isn't anything that you could really call normal, correct posture. All of us are different shapes and sizes and our spines are no exception to that rule.
The spine has a series of curves to make the S shape that we can see when we look at someone side on.The curve at your low back that bends inwards is called a lordosis, if you have a particularly deep curve you are said to have a lordotic posture. If it is reduced it is described as a ‘flat back’, ‘sway back’ or straight back posture.
The curve that bends outwards in your mid back, between your shoulder blades, is called a kyphosis. If you are stooped or round shouldered you may be described as having a kyphotic posture or a stooped posture.
At the top of the S, the spine curves in again at the neck to form another lordosis.
All of these different postures are normal and nothing to worry about because the amount of curve in the S shape can vary greatly between individuals and there is no absolute rule about what is normal or good posture.
There is also no evidence that one type of back shape is more likely to lead to back pain than another. Some researchers (1) have found no difference in low back posture between people with low back pain and those without.
I often meet people who are worried because they have been told they have a kyphosis or a ‘kypholordotic’ posture. These terms simply describe your shape they don’t mean there is anything wrong with you.
However, this does not mean you can ignore correct posture. Any prolonged poor posture can cause back pain, whether it’s a static posture like sitting or standing or lying in bed, or whether it’s an active posture like repetitive bending.
In order to get in control of your simple low back pain you need to reduce the stresses and strains you are asking your spine to deal with. The following sections offer advice to help you understand and change any bad postural habits you may have in order to develop correct posture.
Norton, B. J., Sahrmann, S. A., & Van, D. 2004, "Differences in measurements of lumbar curvature related to gender and low back pain", Journal of Orthopaedic and Sports Physical Therapy, vol. 34, no. 9, pp. 524-534.