Lifting when the body is twisted to the side—either left or right—is a recipe for back pain, often in the thoracic region.
An example is lifting a child into or out of a carseat. The lift + twist action often necessary to do this can torque the rib cage, stress and misalign vertebrae, & set off muscle spasms,
As soon as the child is able to climb in and out of the carseat on their own, give your body a break and let them do it.
In the interim, take care to twist as little as possible when getting them in / out, and try to keep your body as close to them as possible while doing it. This creates shorter-lever stresses on the back and spine, helping to make it less likely that you will injure yourself.
