The greater tubercle is a bony projection located on the upper arm bone, or humerus, of the human body. It is a large, rounded bump located just below the head of the humerus and serves a variety of important functions in the human body, including providing attachment points for various muscles and tendons.
Location
The greater tubercle is located on the humerus, which is the bone that runs from the shoulder to the elbow. The greater tubercle is located on the lateral, or outer, side of the humerus and is positioned just below the head of the humerus. The greater tubercle is separated from the head of the humerus by the intertubercular groove, which is a shallow depression that runs along the length of the humerus.
Structure
The greater tubercle is a large, rounded bump located on the lateral side of the humerus, just below the head of the humerus. It has a number of important features, including the following:
Tuberosity
This is the rounded, bump-like part of the greater tubercle. It serves as an attachment point for various muscles and tendons, including the latissimus dorsi, teres major, and infraspinatus muscles.
Muscular impressions
These are small indentations located on the tuberosity of the greater tubercle. They serve as attachment points for various muscles and tendons, including the teres major and infraspinatus muscles.
Articular surface
This is the smooth, flat surface of the greater tubercle that forms the shoulder joint with the scapula. It is covered with a layer of cartilage, which helps to reduce friction and allow smooth movement of the joint.
Function
The greater tubercle serves a variety of important functions in the human body, including the following:
- Providing attachment points for various muscles and tendons: The greater tubercle serves as an attachment point for a number of muscles and tendons, including the latissimus dorsi, teres major, and infraspinatus muscles. These muscles help to move and stabilize the shoulder joint.
- Forming part of the shoulder joint: The greater tubercle, along with the head of the humerus, forms the shoulder joint with the scapula. The shoulder joint is a ball-and-socket joint, which allows for a wide range of movement, including flexion, extension, abduction, adduction, and rotation.
- Providing stability to the shoulder joint: The greater tubercle helps to stabilize the shoulder joint by providing attachment points for various muscles and tendons, including the latissimus dorsi, teres major, and infraspinatus muscles. These muscles help to keep the shoulder joint in place and prevent excessive movement.
Clinical significance
Despite its small size and relatively low profile, the greater tubercle is clinically significant and can be involved in a number of conditions and injuries.
Fractures
The greater tubercle can fracture, or break, due to trauma or overuse. These fractures are generally classified as either complete or incomplete. Complete fractures involve a complete break in the bone, while incomplete fractures involve a partial break or crack in the bone. Symptoms of a greater tubercle fracture may include pain, swelling, bruising, and difficulty moving the arm. Treatment of a greater tubercle fracture may involve rest, ice, physical therapy, and/or surgery, depending on the severity of the fracture.
Rotator cuff injuries
The greater tubercle is involved in injuries to the rotator cuff, which is a group of muscles and tendons that help to move and stabilize the shoulder joint. These injuries can range from mild strains to more severe tears, in which the muscles and tendons are torn or disrupted. Symptoms of a rotator cuff injury may include pain, weakness, and difficulty lifting or rotating the arm. Treatment of a rotator cuff injury may involve rest, ice, physical therapy, and/or surgery, depending on the severity of the injury.
Bicipital tendonitis
The greater tubercle can also be involved in bicipital tendonitis, which is a condition in which the tendon that connects the bicep muscle to the greater tubercle becomes inflamed due to irritation or overuse. Symptoms of bicipital tendonitis may include pain, weakness, and difficulty lifting or rotating the arm. Treatment of bicipital tendonitis may involve rest, ice, physical therapy, and/or medication, depending on the severity of the condition.
Other conditions
The greater tubercle can also be involved in other conditions, including impingement syndrome (a condition in which the tendons or bursae of the shoulder become inflamed due to irritation or compression) and osteoarthritis (a degenerative joint disease that causes pain, stiffness, and loss of function). Treatment of these conditions may involve rest, ice, physical therapy, and/or medication, depending on the specific condition and its severity.
