The Shoulder Joint

Clayton Payne

Deltoid

Origin - Clavicle, Acromion and Spine of Scapula

Insertion - Lateral Surface of Humerus

Joints Crossed - Shoulder

Joint Actions - Anterior fibres flex the shoulder and assist in horizontal flexion and medial rotation, All fibres abduct the shoulder, Posterior fibres extend the shoulder and assist in lateral rotation

Pectoralis Major

Origin - Clavicle, Sternum and Cartilage of Ribs 1 - 6

Insertion - Top of Humerus

Joints Crossed - Shoulder Joint

Joint Action - Shoulder horizontal flexion, adduction and medial rotation

Latissimus Dorsi

Origin - Via Thoracolumbar Fascia (TLF) from spinous processes of T6 - T12, Lumbar and Sacral Vertabrae and Iliac Crest. Also lower 3 - 4 Ribs and bottom edge of Scapula

Insertion - Top of Humerus

Joints Crossed - Shoulder Joint

Joint Action - Origin fixed: adducts and extends arm. Assists in medial rotation of arm. Depresses shoulder girdle via insertion of humerus. Insertion fixed: tilts the pelvis forward

Teres Major

Origin - Lateral border of the Scapula ner the inferior angle

Insertion - Humerus

Joints Crossed - Shoulder Joint

Joint Action - Medial rotation, adduction and extension of shoulder joint