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Primarily (90% of the time, especially in a resting position) this job is performed by the supraspinatus muscle, and is assisted slightly by the infraspinatus and teres minor. When you are lifting something, or actively using the arm it tends to be the larger deltoids muscle that will kick in and keep the humerus from displacing inferiorly.
What else can I help you with?
Why would a dislocated shoulder also potentially result in injury to the rotator cuff?
Rotator Cuff Muscles (SITS) Supraspinatus Infraspinatus Teres Minor Subscapularis Rotator cuff muscles all attach to the head of the humerus and act to seat the head of the humerus firmly in the glenoid fossa to prevent shoulder dislocation. A dislocated shoulder means some/all of these muscles have been torn.
What is the pink structure covering the head of the humerus?
Rotator cuff
What group of muscles holds the head of the humerus securely in place as it rotates within the shoulder joint?
rotator cuff
What bone do the muscles of the rotator cuff originate?
The rotator cuff muscles are referred to occasionally as the SITS muscles. The Supraspinatus, Infraspinatus, Teres minor and the subscapularis. The Supras. originates on the scapula and inserts on the humerus. The Infras. originates on the scapula and inserts on the humerus(greater tubercle. The Teres minor originates on the scapula and inserts on the humerus. The Subscapularis originates on the scapula and inserts on the humerus(lesser tubercle). The function of this muscle group is to stabilize the shoulder joint. Hope this helps.
What muscles make up the rotator cuff and how do they contribute to shoulder stability and movement?
The rotator cuff is made up of four muscles: the supraspinatus, infraspinatus, teres minor, and subscapularis. These muscles work together to stabilize the shoulder joint and allow for a wide range of movement. They help to keep the head of the humerus (upper arm bone) centered in the shoulder socket during arm movements, preventing dislocation and providing strength and control for activities like lifting and reaching.
What muscle is the main antagonist of medial rotation of the humerus?
The main antagonist of medial rotation of the humerus is the infraspinatus muscle, one of the rotator cuff muscles. It works in opposition to the muscles that perform medial rotation, such as the subscapularis.
The supraspinatus is named for its location on the posterior aspect of the scapula above the spine What is its action?
The action of the supraspinatus is to stabilize the shoulder joint and help prevent downward location of the humerus and to assist in abduction.
What is the proximal epiphyseal line on the humerus called?
The proximal epiphyseal line on the humerus is commonly referred to as the "greater tubercle." It is a prominent bony projection located near the head of the humerus and serves as an attachment point for several muscles of the shoulder, including the rotator cuff. This line represents the site of growth plate fusion that occurs after skeletal maturity.
What are the actions of the rotator cuff muscles?
The rotator cuff muscles help stabilize and move the shoulder joint. They work together to rotate the arm and lift it away from the body. These muscles also play a crucial role in maintaining shoulder stability and preventing dislocation during arm movements.
What can be shown by abnormal placement of the dye?
The abnormal placement of dye may indicate rheumatoid arthritis, cysts, joint dislocation, rupture of the rotator cuff, tears in the ligament and other conditions.
What are the actions of the rotator cuff muscles in the shoulder joint?
The rotator cuff muscles in the shoulder joint help to stabilize and rotate the arm bone (humerus) within the shoulder socket. They also assist in lifting and rotating the arm, as well as providing support and control during arm movements.
What are possible abnormal results from an arthography procedure?
The abnormal placement of dye may indicate rheumatoid arthritis, cysts, joint dislocation, tear of the rotator cuff, tears in the ligament, and other conditions.
