Detection of Early Scapular Dyskinesis

This study is a prospective blind contrast between periscapular muscle thickness measured with MSUS in patients with early AS in comparison to patients with mechanical dyskinesis and to correlate it with EMG findings.

Inclusion Criteria: * treatment-naïve patients with ankylosing spondylitis (AS), who fulfilled the Assessment of Spondylarthritis Society (ASAS) criteria for axial spondyloarthritis (ax-SpA) * Inclusion criterion for the second group (non-AS individuals) was patients complaining of discomfort upon activity. Exclusion Criteria: * The exclusion criteria of the first group included: 1. patients with a history of local trauma 2. and/or surgical intervention, 3. neuromascular deficits, 4. chronic chest disease and 5. other inflammatory autoimmune/rheumatologic conditions. * Exclusion criteria for the second group were: 1. a history of AS or 2. other systemic autoimmune/ rheumatologic disease.