ABSTRACT
The chronic inflammation associated with ankylosing spondylitis (AS) affects the sacroiliac joints and the synovial joints of the spine. Bony fusion of these joints and ossification of the longitudinal ligaments leads to total immobility of the spine. The fusion of joints and the adoption of a less painful posture may lead to an increasing kyphosis at later stages of the disease (1). As a consequence of the spinal kyphosis, patients are not able to sit, stand, or lie comfortably. In severe cases, patients may be unable to look above the level of the horizon, causing problems in daily activities, like talking to another person, participating in traffic, and getting something above their head.
