Final answer:
Movement at the shoulder joint moving the arm laterally away from the body is called lateral (external) rotation and is an action performed by the muscular system, which allows both voluntary and involuntary movements.
Step-by-step explanation:
The movement at the shoulder joint that moves the upper limb laterally away from the body is known as lateral (external) rotation. This type of movement involves the muscles around the shoulder joint and is part of the bodily actions performed by the muscular system. Large muscles in the torso, neck, arms, and legs are responsible for major movements, and the actions of these skeletal muscles are generally broken down regionally, from the head down to other body parts. The muscular system allows for movements such as flexion and extension, and for rotational movements around bones' longitudinal axis, which includes both medial rotation towards the body's midline and lateral rotation away from it. Practicing activities like yoga illustrate the voluntary use of the muscular system, which also includes involuntary movements that occur within the body, such as the heart beating or digestion.