That is true. The first impression is of course very unusual, because we are used to normal chairs with a fixed seat, on which we are sitting with relaxed back muscles, which on the other hand is leading to spine injuries.

The main idea of the SpinaliS chair is to sit as on a therapeutic ball, where the body has to maintain balance all the time.

This is indeed for the first couple of hours or even days somewhat straining — yet after a few days the body adapts to it excellently.