Inclusion Criteria:  For AS and nr-axSpA;  Diagnosed with AS and nr-axSpA by a rheumatologist according to ASAS criteria, Diagnosed with AS and nr-axSpA at least two years ago, Volunteer to participate in the study, Individuals between the ages of 18-65 will be included in the study.  For Healthy volunteers;  Volunteer to participate in the study, Individuals between the ages of 18-65 will be included in the study.  Exclusion Criteria:  For AS and nr-axSpA;  Having orthopedic problems in the lower extremity, Locomotor disorders (fractures and prostheses) and / or osteoporosis, Having a history of lower extremity and spine surgery, Having neurological and cognitive problems, Having vision and hearing problems, Regular exercise, Individuals with kyphosis above 50 degrees will be excluded from the study.  For Healthy volunteers;  Having any musculoskeletal, neurological and rheumatological diseases, Having any condition (advanced respiratory or orthopedic problems, fracture, sprain or spine surgery) that will prevent the evaluation, Regular exercise, Individuals who do not agree to participate in the study will be excluded from the study.