Anatomy 9501 lecture 8: joints of shoulder & elbow. This is the only bony connection to the axial skeleton. Sternum = sc joint: acromion (scapula) = ac joint. What: supports upper limb, allows scapular rotation, transmits impactful forces to axial skeleton. The majority of clavicular fractures occur in the middle 1/3 (80% of them). These joints consist of 2+ bones, each covered by articular/hyaline cartilage. They contain: articular cartilage, synovial membrane this secretes synovial fluid, fibrous joint capsule, additional features: articular disc, labrum these are all joint specific. This joint is a synovial joint with an articular disk. ** it is a saddle joint therefore it acts as a ball and socket joint. It is used to extend the reach of the upper limb. This joint is also a synovial joint. It is a plane joint therefore it permits gliding and sliding motions.