Participants
The study included men and women aged 18 years or older who were willing
and capable of uploading videos from a smartphone or webcam. People with
axSpA were recruited through the local National Axial Spondylosis
Society (NASS) network, and people who reported no long-standing back
pain were recruited through social media and advertisement. Individuals
were excluded from participation if they had surgery within six months,
were unable to stand independently, were unable to pass screening
questions to participate in physical activity (Physical activity
readiness questionnaire, PAR-Q), had a serious neurological condition
preventing normal movement or walking ability, or had any severe medical
conditions. A minimum of 17 participants were required per group (axSpA
and non-back pain groups), assuming 1-beta =0.90, alpha=0.05 and effect
size |ρ|=0.50.