AVOID ALL ROTATIONS OF THE SHOULDER GIRDLE AND RIB CAGE AGAINST THE PELVIC GIRDLE

The central segment, the rib hump, is enlarged as it rotates backwards into the existing curvature, regardless of whether the rotation is to the left or right side.

Spinal Twist - Ardha Matsyendrasana (photos in sidebar at left)
This exercise is excellent for straight, normal backs. In it, the internal organs are squeezed, that is, freed of waste.

However, people with scoliosis should absolutely avoid the Spinal Twist. A scoliotic body usually has three or four contortions (counter-rotations) between the pelvis, rib cage, and shoulder girdle. These are exacerbated by twisting the shoulder girdle against the pelvic girdle while the middle section, the rib cage, is ignored.

That middle section is precisely where the prominent rib hump is located, and on the other side the rib valley. Whether the torso is twisted left or right, the rib hump and the rib valley will increase. If you twist so far that you can hear your spine crack, that is a sign that the spinal rib joints are moving further into an abnormally twisted state. It does no good to do this movement once to the right and once to the left: it is counterproductive in both cases.

Triangle - Trikonasana
To be completely avoided in scoliosis, because here the shoulder girdle is twisted against the pelvic girdle and the middle section (which thereby creates a rib hump) must follow after the more comfortable side.
Other inappropriate twisting exercises for scoliosis

* Bharadvajasana - Seated twist
* Marichyasana - Sage twist
http://www.schrothmethod.com/about/y...scoliosis-menu