What is the distal attachment of the deltoid muscle?

The deltoid muscle's distal attachment is located at the deltoid tuberosity of the humerus. This is a prominent ridge on the lateral aspect of the humerus, and it serves as the point where the deltoid muscle exerts its force during arm movements. The deltoid muscle is crucial for shoulder abduction, flexion, and extension, and the deltoid tuberosity provides a surface area for the muscle to anchor effectively.

This distinction in attachment is important for understanding how the deltoid contributes to shoulder function and mobility. It highlights the muscle's role in providing stability and strength to the arm during various activities, such as lifting and reaching. The other options represent attachments or landmarks relevant to other muscles or structures not associated with the deltoid.