What is the primary function of the scapula?

The primary function of the scapula, commonly known as the shoulder blade, is to connect the arm to the torso. This bone plays a critical role in providing an attachment point for muscles that facilitate the movement of the arm. It forms a key part of the shoulder girdle, allowing for a wide range of motion and mobility in the shoulder joint, which is essential for various activities such as lifting, throwing, and reaching. The scapula's structure also aids in stabilizing the shoulder joint during these movements, making it a vital component for upper body functionality.

This connection enhances the overall movement mechanics of the arm, allowing for coordinated and effective movement patterns necessary in numerous physical tasks. The other choices do not accurately reflect the primary role of the scapula in the skeletal system.