Final answer:
Contraction of the latissimus dorsi muscle primarily leads to extension, adduction, and medial rotation of the arm at the shoulder joint, as well as inferior rotation of the scapula during upper limb adduction.
Step-by-step explanation:
When the latissimus dorsi muscle contracts, it affects the movements of the glenohumeral joint by contributing to several key functions. These functions include extension, adduction, and medial rotation of the humerus at the shoulder joint. Specifically, the latissimus dorsi helps to bring the arm back towards the body (adduction) from an abducted position and to rotate the humerus inward. Additionally, when the latissimus dorsi contracts, it also facilitates the inferior rotation of the scapula during upper limb adduction, where the glenoid cavity moves downward, while the medial end of the scapular spine moves upward. This action is essential for the full range of motion required for activities such as pulling something down forcefully or swimming.