Does sitting slouched and slanted cause scoliosis?

July 20, 2010, Lenia Teo, Physiotherapist

Question: My daughter sits with a slouch, and sometimes sits with her body slanted to one side, will that cause scoliosis?

No. Sitting with a slouch or in any other bad posture does not lead to scoliosis. When we discuss about scoliosis, we typically mean idiopathic scoliosis, a form of scoliosis caused by genetic factors which lead to uneven growth of the spine. Curvature of the spine from bad posture is known as postural scoliosis and is reversible.

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Posture and scoliosis

Human skeletons are mainly supported by muscles and ligaments. The center of gravity of the skeleton varies when its alignment changes, which in turn affects how much the muscles have to work to maintain its stability. Therefore, “bad postures” refer to postures in which the body structures need to work harder in order to maintain a particular position, and “good postures” refer to postures in which the muscles work the least.

In an upright posture, the ideal posture is one that if looked from the side, the ear is right above the shoulder, and the shoulder right above the hip. Any posture that deviates from which would be requiring more effort from the muscles. So, sitting slouched or slanted to one side would require more muscle work on one side of the body, which may lead to overuse and tightness of those muscles.
In the case that one stays in a faulty posture for long and causes muscle imbalance, the spine may be slightly curved due to uneven muscle tension. This type of curve is called postural scoliosis, which is not the same with scoliosis that is caused by bone deformities. If taking a spine X-ray in lying, this type of scoliosis will disappear on the X-ray film.

So, bad posture may cause postural scoliosis, but it will not cause bone deformity. The good news is that postural scoliosis is completely reversible by exercises and posture re-training.

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