This arthritis affects a joint at the top of your shoulder. It's where the shoulder blade's bony protrusion (called the "acromion") meets the clavicle. This joint acts as a pivot point when you raise your arm above your head.

The shoulder is a complex structure made of three separate joints. They work together to give the shoulder a tremendous range of motion. Let's take a closer look at the main parts of the shoulder's anatomy.

Tendons are strong bands of tissue that connect muscle to bone. With this injury, one of the tendons anchoring your biceps muscle is torn. It may be torn partially or completely. Because the biceps is attached with two separate tendons, you may find that you can still use your biceps muscle even if one tendon is completely torn.

This is a problem with a tendon in your shoulder. Most often, it's the "long head of biceps" tendon. It travels from the front of your upper arm to the top of your shoulder socket. With this condition, the tendon becomes painfully inflamed or irritated.

This is a problem with a tendon in your elbow. It's called the "distal biceps tendon." It connects the biceps muscle of your upper arm to the radius bone at the elbow. With this condition, the tendon becomes painfully inflamed or irritated.

These are warm or painful sensations caused by an injury to the brachial plexus. This is a network of nerves that passes through your shoulder. They travel down your arm and to your hand.

This is a swelling of a fluid-filled sac called the "subacromial bursa." It's in the shoulder, between a bony protrusion called the "acromion" and the rotator cuff. You have similar sacs near other large joints throughout your body. They act as cushions between your bones and your soft tissue. Normally they have a small amount of fluid inside them. But sometimes they can swell. We call that "bursitis."

This painful condition occurs when calcium deposits form in tendons of the rotator cuff. These tendons and surrounding tissues in the shoulder become inflamed. This condition typically affects adults.

This painful condition occurs when calcium deposits form in tendons of the rotator cuff. These tendons and surrounding tissues in the shoulder become inflamed. Reactive calcification often develops in young people, but it can affect people of all ages.

This is a common shoulder injury. It's a break of the bone that rests between the shoulder blade and the sternum. We call it the "collarbone." Your collarbones help connect your arms to your body.

This is a shoulder injury. It's a break of the bony bump on the outer side of the humerus. That's the bone of your upper arm. The greater tuberosity is the place where three muscles of the rotator cuff attach. So a fracture here hurts your shoulder's stability and movement.

"This is a fracture of a part of the shoulder blade called the ""glenoid."" This is the socket that holds the head of the humerus (the bone of the upper arm). A glenoid fracture can allow the head of the humerus to slip out of the socket. "

This condition is a break of the scapula, the large, flat, triangular bone that contains the shoulder socket. Because the scapula is well protected by the muscles of the shoulder, scapula fractures are uncommon.

This is stiffening of your shoulder. It happens over time, and you may not know what caused it. With a frozen shoulder, it can be hard for you to be as active as you like.

If you have pain in your shoulder, you may have a torn labrum. That's the thick band of tissue that goes around your shoulder socket. It helps make the socket deeper. It cushions the bone of your upper arm and keeps it from slipping.

This is a shoulder injury. It's a compression fracture that creates a dent in the head of the humerus. That's the ball of the arm bone that fits into your shoulder socket. The dent interferes with the motion of your shoulder.

Joint pain is a common problem for many people. It can keep you from doing the things you want to do. It can make it hard for you to be as active as you like. Let's take a moment to learn about the causes of joint pain, and what you can do about it.

Some of the muscles in your shoulder have opposing roles. When you move your arm, certain muscles contract while their opposing muscles relax. But when a muscle becomes much stronger than its opposing muscle, your shoulder can become unstable. You may have trouble moving it normally. We call this a "muscle imbalance."

This common injury is a stretching or tearing of the trapezius. This large muscle group spans the upper back, shoulders and neck. These muscles are commonly called the "trap" muscles.

Osteoarthritis, also called degenerative arthritis, is a gradual breakdown of cartilage in the joints. Cartilage is a tough, flexible connective tissue that protects the ends of bones in the joints. Osteoarthritis of the shoulder can severely impact a person's lifestyle.

If you have an infection in a bone, you have osteomyelitis. It's a serious condition that can cause part of your bone to die. And, the infection can spread to other parts of your body.

This condition is a fracture of the head of the humerus - the "ball" of the shoulder's ball-and-socket.

Rheumatoid arthritis is a disease of the immune system. This is the system that protects you from infection. RA may cause pain and stiffness in your shoulder where the humerus (the bone of the upper arm) meets the shoulder socket. It can also affect the joint where your clavicle meets your scapula.

The rotator cuff muscles and tendons hold your upper arm bone in your shoulder socket. A hard fall, repetitive arm motions or problems with the structure of your shoulder can injure the rotator cuff.

The rotator cuff is a group of muscles and tendons in each shoulder. It holds your upper arm bone in your shoulder socket. It keeps your arm stable while allowing it to lift and rotate. Too much stress on the rotator cuff can cause a tear. This can be a painful injury.

The shoulder is a ball-and-socket joint. The ball of your upper arm bone fits into a socket in your shoulder blade. If the ball slips out, your shoulder has "dislocated."

This is a painful pinching of soft tissues in your shoulder. It happens when these tissues rub and press against a part of your shoulder blade called the "acromion." This can irritate your rotator cuff tendons, and also a soft sac called the "subacromial bursa."

This is a looseness of the shoulder joint. With it, your arm slides around too much in the socket. It may slip out of the socket easily. Instability can happen because the ligaments that hold your shoulder together aren't tight enough. Or, the cartilage around your shoulder socket may be damaged.

Our shoulders are the most movable joints in the body. They give our arms great range of motion. They allow us to lift and control heavy loads. Shoulder pain is a problem many of us feel at some time in our lives. Let's learn about shoulder pain, and what you can do about it.

This is an injury of the acromioclavicular joint (commonly called the "AC" joint). This is the joint where the clavicle meets the scapula. A shoulder separation is a stretching or a tearing of the ligaments that support these bones. This allows the bones to move out of position.

This is a shoulder injury. It's a tear of the labrum. That's a ring of cartilage that surrounds the shoulder socket and helps hold the head of the humerus in place. This type of tear happens where the biceps tendon attaches to the labrum.

This is a problem that involves the scapula. That's the bone we call the ""shoulder blade."" With this condition, you have a shoulder blade that catches when you lift or move your arm. You may find this only slightly irritating, or it may be very painful. 

This is a pain or weakness from an irritated nerve in your shoulder. It's called the "suprascapular" nerve. It travels from the neck down through your shoulder.

This is a label given to a group of disorders. In these disorders, nerves or blood vessels are compressed in the space between your collarbone and the underlying rib. This space is called the "thoracic outlet."

If overuse has led to pain in the front of your shoulder, you may have an injury we call "weightlifter's shoulder." It's a type of damage that most often affects the end of the clavicle (commonly called the "collarbone").

This is a problem of the scapula bone. That's your "shoulder blade." With this condition, you have a shoulder blade that sticks out instead of lying flat. It lifts away from your back, and it doesn't look like your other shoulder blade.