The deltoid tuberosity of the humerus is a bony prominence located on the lateral surface of the proximal humerus. It serves as the insertion site for the deltoid muscle, which abducts and laterally rotates the arm. The deltoid tuberosity is adjacent to the greater tubercle, lesser tubercle, and surgical neck of the humerus. It is also located near the axillary nerve, which innervates the deltoid muscle.
The Deltoid Tuberosity: A Comprehensive Overview
The deltoid tuberosity is a prominent bony projection on the lateral aspect of the humerus, the upper arm bone. It is the site of attachment for the deltoid muscle, which is responsible for abducting (lifting) the arm away from the body.
Anatomy
The deltoid tuberosity is located approximately at the midpoint of the humerus, slightly below the surgical neck. It projects laterally from the bone and has a roughened surface for the attachment of the deltoid muscle.
Shape and Orientation
The deltoid tuberosity is typically triangular in shape, with its apex pointing distally (towards the elbow). It has three surfaces:
- Lateral surface: Faces laterally and provides attachment for the middle deltoid fibers.
- Anterior surface: Faces anteriorly and gives attachment to the anterior deltoid fibers.
- Medial surface: Faces medially and provides attachment for the posterior deltoid fibers.
Clinical Significance
- Deltoid Tuberosity Fracture: A fracture of the deltoid tuberosity can occur due to a direct blow or fall onto the shoulder. It can result in a loss of shoulder function and may require surgical intervention.
- Calcific Tendinitis: Calcium deposits may accumulate on the deltoid tendon at its attachment to the deltoid tuberosity. This can cause pain, stiffness, and decreased range of motion.
- Impingement Syndrome: The deltoid tuberosity can impinge upon the overlying structures in the shoulder joint, such as the acromion process (part of the scapula). This can lead to pain and limitation of arm movement.
Table: Measurements of the Deltoid Tuberosity
| Measurement | Value |
|---|---|
| Length | 2.5 – 5.0 cm |
| Width | 1.5 – 2.5 cm |
| Height | 1.0 – 1.5 cm |
Question 1:
What is the deltoid tuberosity of the humerus?
Answer:
The deltoid tuberosity of the humerus is a triangular-shaped projection that extends laterally from the proximal shaft of the humerus. It serves as the attachment point for the deltoid muscle.
Question 2:
Where is the deltoid tuberosity of the humerus located?
Answer:
The deltoid tuberosity of the humerus is located approximately halfway down the shaft of the humerus, on its lateral aspect. It is just distal to the surgical neck and proximal to the radial groove.
Question 3:
What is the function of the deltoid tuberosity of the humerus?
Answer:
The deltoid tuberosity of the humerus provides a strong attachment for the deltoid muscle, which is primarily responsible for abducting the arm (moving it away from the body).
Well, there you have it, folks! The deltoid tuberosity of the humerus: the unsung hero of our shoulders. From providing stability to helping us reach for the stars, it’s a small but mighty part of what makes us human. Thanks for hanging out with me while we dive into the fascinating world of anatomy. Be sure to drop by again sometime. I’ll have more exciting bone-related adventures in store for you. Stay curious, and keep exploring the amazing world of the human body!