PHTY101 Lecture Notes - Lecture 2: Glenohumeral Ligaments, Ulnar Notch Of The Radius, Articular Disk
Document Summary
Close packed position: midway between pronation and supination, with 90 degrees of flexion. Articular capsule: thickest and strongest at sides of joints, relatively weak anteriorly and posteriorly- strengthened by collateral ligaments on sides. Ligaments: annular, prevents inferior dislocation of head of radius, allows radius to pivot through pronation and supination, collateral ligaments: tense throughout flexion and extension range, radial collateral- prevents adduction, ulnar collateral- prevents abduction. Articular disc: from styloid of ulna to margin of ulnar notch of radius, therefore not between the articular surfaces, more like a ligament, unlike other joints, disc sits underneath joint. Syndesmosis: fibres in diagonal direction- role in dissipating forces between bones, binds bones together. Dissipating forces: radius cops force initially, transferred to ulna, then humerus, shoulder girdle and axial skeleton. Gh joint stability: orientation of glenoid fossa- angles up and laterally, coracohumeral and glenohumeral ligament, superior capsule.
