Table 2 Items in the Bath Ankylosing Spondylitis Functional Index (BASFI), scored on a numerical rating scale [18]

Putting on your socks or tights without help or aids (e.g., sock aid).

Bending forward from the waist to pick up a pen from the floor without an aid.

Reaching up to a high shelf without help or aids (e.g., helping hand).

Getting up out of an armless dining room chair without using your hands or any other help

Getting up off the floor without help from lying on your back.

Standing unsupported for 10 min without discomfort.

Climbing 12 to 15 steps without using a handrail or walking aid. One foot at each step.

Looking over your shoulder without turning your body.

Doing physically demanding activities (e.g., physiotherapy, exercises, gardening or sports).

Doing a full days activities, whether it be at home or at work.