FUNCTION Voluntary contributor of summaries featured in the "Musculoskeletal" section. SPECIALTIES Spinal pain, shoulder and hip dysfunctions Jonathan Ko (Australia (origin: South Korea)) BAppSc Physiotherapy, MSportsMuscPhysio Author About the Author Willem-Paul Wiertz Latest articles from this auhtor Morphological study of the inferior transverse scapular ligament Thoracic outlet syndrome: A neurological and vascular disorder. Rotator cuff muscles perform different functional roles during shoulder external rotation exercises. Posterior shoulder instability: current concepts review. Diagnostic performance and reliability of ultrasonography for fatty degeneration of the rotator cuff muscles.