- Autoimmune disorder that leads to fusing of vertebral joints
- Slow, insidious onset LBP
- Progressive loss of range of motion, diminished forward flexion as bones fuse
- Low back pain radiates into buttocks
- LBP doesn't improve w/rest; morning stiffness; tends to get better w/exercise/use
- Can have peripheral joint pain
- Tendon insertion pain
- Eye pain, redness, and tearing from uveitis
- Pain over Sacro-Iliac joints
- Limited range of motion in spine; limited chest expansion
- Peripheral joint pain and swelling
- Enthesiitis→ tendon insertion pain/swelling
- Eye redness and pain