Rotator Cuff
The Rotator Cuff
What is it and Why is it important?
In the morning, you reach for a coffee cup on the upper shelf in your kitchen cabinet. While getting dressed for work, you brush your hair. At the office, you reach behind your chair to grab a file. After work, you play a game of tennis with a buddy or go for a swim. All these activities have something in common. They involve the use of your shoulder muscles, which together are called the rotator cuff. The shoulder is one of the most complicated and sophisticated joints in the human body. It has the greatest range of motion, allowing you to move your arm in all directions. If you start paying attention, you’ll realize just how often you use your shoulder joint in daily life. The rotator cuff is a vital cog in the wheel of shoulder joint anatomy and function. Yet, oftentimes, we take it for granted. In this article, we give you the lowdown on the rotator cuff. What it is and why it’s important. We also touch briefly on the common injuries and conditions that can cause pain in your rotator cuff.
Shoulder Anatomy: An Overview
First, let’s do a quick review of shoulder joint anatomy. The shoulder joint (medical term: glenohumeral joint) is a ball-and-socket joint. It consists of a large “ball,” which is the spherical top end of the humerus (upper arm bone) that fits into the glenoid fossa of the scapula (a shallow cavity or “socket” in the shoulder blade). This anatomy makes the shoulder the most mobile joint in the body. However, this mobility and function come at the cost of stability. That’s where the rotator cuff comes in. It provides stability to the shoulder joint while allowing a wide range of movement.
What is the Rotator Cuff?
Understanding this complex joint
The rotator cuff is the name for a group of four separate muscles and their tendons. (A tendon is a tough band of fibrous tissue that connects a muscle to a bone and can withstand considerable amounts of tension). The four muscles of the rotator cuff provide strength and stability to the shoulder joint. The rotator cuff muscles keep the upper arm bone from slipping out of the shoulder socket. The muscles are also responsible for many shoulder movements, such as
Rotator Cuff Muscles
The rotator cuff consists of 4 muscles
Muscles
- Supraspinatus
- Infraspinatus
- Teres minor
- Subscapularis
Read on to learn more
Supraspinatus: It keeps the humerus (upper arm bone) firmly pressed against the glenoid fossa (shoulder socket). In addition to providing stability, the supraspinatus is used when you lift your arm against gravity.
Infraspinatus: It is responsible for external rotation of the shoulder (movement of the shoulder out and away from the center of the body). In everyday life, you use the infraspinatus when you put your hands behind your neck, for example, to do your ponytail.
Teres minor: The smallest rotator cuff muscle assists in moving the arm away from the body. It also helps stabilize the shoulder joint by holding the humeral head (ball) in the glenoid cavity (socket).
Subscapularis: It is responsible for internal rotation (movement of the shoulder in and toward the center of the body). When you work out in the gym, you use this movement to keep the bar close to your body. The subscapularis prevents displacement of the humeral head from the glenoid fossa.
Conditions of the Rotator Cuff
Injuries, poor posture, overuse, repetitive movements, and normal wear and tear of the shoulder joint and rotator cuff muscles can lead to symptoms like pain and weakness. This can make it difficult and painful to perform basic activities of daily living, such as reaching, lifting, carrying objects, getting dressed, and sleeping. Some of the common problems that affect the four rotator cuff muscles include:
Rotator cuff tear: When one or more of the tendons of the rotator cuff is injured or torn, it can cause pain and weakness. Rotator cuff tears are common in older individuals and can be treated with physical therapy, anti-inflammatory medications, and cortisone (steroid) injections. In some patients, a rotator cuff tear may require surgery to repair the torn tendons.
Calcific tendonitis: In middle-aged individuals (more commonly women), small calcium deposits can form in the tendons of the rotator cuff, leading to inflammation and severe pain. The condition is called Calcific tendonitis and occurs more often in the right shoulder than the left for unknown reasons. People with endocrine disorders like diabetes or hypothyroidism (underactive thyroid) are at greater risk of rotator cuff tendonitis. Conservative treatment consisting of rest, icing, pain medications, and physical therapy is usually effective. Occasionally, rotator cuff tendonitis may require
surgical treatment.
Rotator cuff tendonitis: In middle-aged individuals, inflammation of the tendon of the rotator cuff can lead to pain and weakness. The condition is called rotator cuff tendonitis which is treated with physical therapy, anti-inflammatory medication, cortisone (steroid) injections and some may require surgery.
Shoulder bursitis: A bursa is a small fluid-filled sac that provides cushioning and reduces friction between muscles, tendons, and bones. The shoulder bursa protects the rotator cuff tendons and allows them to slide smoothly in the narrow space between the humerus and the acromion (tip of the shoulder). Injury or overuse of the shoulder joint can lead to inflammation of the bursa, a condition known as shoulder bursitis, characterized by pain on the outside of the shoulder, worse with overhead activities.
Shoulder impingement: This is a condition in which there is inflammation of the rotator cuff tendons as well as the shoulder bursa. The term impingement refers to a pinching of the rotator cuff tendons and bursa in the narrow space between bones, leading to pain, which is typically worse with overhead movements and at night. Most people find relief with conservative treatments such as rest, icing, and anti-inflammatory medications. Cortisone injections are also commonly used to treat shoulder impingement.