Final answer:
The muscles responsible for arm movement around the trunk are attached from the humerus to the scapula and clavicle, with pivotal roles played by the deltoid, pectoralis major, and various other shoulder muscles.
Step-by-step explanation:
The muscles that allow for arm movement around the trunk attach the humerus to the scapula and clavicle.
The pectoral girdle, consisting of the scapula and clavicle, serves as the attachment point for various muscles that move the arm.
Specifically, muscles such as the deltoid, pectoralis major, latissimus dorsi, subscapularis, supraspinatus, infraspinatus, teres major, teres minor, and coracobrachialis originate on the scapula and clavicle to stabilize and move the humerus, allowing for a wide range of arm movements.