Common Shoulder Injuries

The shoulder is one of the most complex and mobile joints in the human body. This incredible range of motion, however, comes with a trade-off: vulnerability. Because we rely on our shoulders for countless daily activities, from reaching for a high shelf to playing sports, an injury can significantly impact quality of life. Understanding the nature of common shoulder injuries is the first step toward effective treatment and a successful recovery. In this post, we’ll explore the most frequent issues that affect the shoulder joint.

• For many common shoulder injuries, treatments like physical therapy, rest, and anti-inflammatory medications can be effective. Surgery is typically reserved for cases that do not respond to conservative care.
• Rehabilitation is a key aspect of recovery for many shoulder conditions. A dedicated physical therapy program helps restore strength, flexibility, and range of motion.
• Learning to adjust how you perform certain activities can help reduce stress on the joint and prevent re-injury, especially during the healing process.

The shoulder is a ball-and-socket joint. It is formed by three main bones: the humerus (upper arm bone), the scapula (shoulder blade), and the clavicle (collarbone). The head of the humerus fits into a shallow socket in the scapula called the glenoid. This structure allows for a remarkable degree of movement. However, the shallow socket means the joint relies heavily on surrounding soft tissues for stability.

These soft tissues include the ligaments, the joint capsule, and the muscles and tendons of the rotator cuff. The rotator cuff is a group of four muscles and their tendons. They surround the shoulder joint. Their primary job is to keep the head of the humerus centered in the glenoid socket. They also help to lift and rotate the arm. When any of these structures are damaged, the result is often pain, weakness, and limited mobility.

Shoulder injuries can affect people of all ages and activity levels. In the following subsections, we will explore some of the most frequently diagnosed shoulder conditions.

The rotator cuff is made up of four tendons that wrap around the head of the humerus and help lift and rotate the arm. When one of these tendons is damaged, either partially or fully torn, it can disrupt both strength and stability. Tears may be partial (frayed or damaged tendon) or full-thickness (completely detached from the bone).

Rotator cuff tears typically fall into two categories:

• Acute tears: Often triggered by a sudden event, like lifting something heavy, falling onto an outstretched arm, or experiencing a forceful overhead motion.
• Degenerative tears: Develop slowly over time due to repetitive motions, age-related wear, decreased tendon blood supply, or bone spurs rubbing against the tendon (impingement).

• Deep, dull ache in the shoulder
• Weakness lifting or rotating
• Pain when reaching overhead or behind the back
• Difficulty sleeping on the affected side

Impingement occurs when the rotator cuff tendons become compressed or irritated as they pass beneath the acromion, a bony section of the shoulder blade. When the space narrows, tendons can become inflamed, making overhead movements painful.

The space under the acromion can become too tight due to:

• Repetitive overhead activity (e.g., swimming, pitching, weightlifting)
• Bursitis (inflammation of the cushioning bursa)
• Tendonitis (swelling within the rotator cuff tendons)
• Abnormal bone shape (a curved or hooked acromion naturally reduces space)
• Poor posture/mechanics

• Pain lifting the arm overhead
• Night pain or weakness
• Discomfort in the front or side of the shoulder

Shoulder instability occurs when the humeral head is not held securely in the glenoid socket. It may partially slip out (subluxation) or fully dislocate, where the ball completely leaves the socket.

• Traumatic injuries, such as a fall, direct hit, or forceful rotation
• Repetitive strain (e.g., overhead athletes may gradually stretch the ligaments)
• Loose ligaments (laxity), as some individuals are naturally more flexible
• Previous dislocation; once the stabilizing structures are stretched/torn, the likelihood of another dislocation increases

• Sudden, sharp pain during dislocation
• Feeling that the shoulder is “loose” or “slips”
• Recurrent episodes of giving way
• Numbness or tingling if nerves are affected

Shoulder arthritis occurs when the protective cartilage that covers the ends of the bones wears away. Without that smooth surface, movement becomes painful and stiff. It can affect either the glenohumeral joint (main ball-and-socket joint) or the AC joint (where the collarbone meets the shoulder blade).

As cartilage breaks down, bone may rub against bone, causing pain, stiffness, grinding sensations, and reduced range of motion. Causes may include:

• Osteoarthritis (age-related wear and tear)
• Post-traumatic arthritis (arthritis following an injury or fracture)
• Inflammatory arthritis (e.g., rheumatoid arthritis)

• Deep, aching pain in the joint
• Pain with activity, especially overhead
• Decreased mobility and stiffness
• Joint grinding, clicking, or popping

A fracture is a break in one of the bones of the shoulder. Depending on the severity, the bone fragments may stay aligned (non-displaced) or separate significantly (displaced).

• High-impact trauma, such as car accidents, sports injuries, or falls
• Simple falls in older adults, often due to weak bones or osteoporosis
• Direct blow to the shoulder

Severe fractures may also damage surrounding tissues like nerves, blood vessels, and tendons, which may complicate treatment decisions.

• Immediate, severe pain
• Bruising and swelling
• Inability to move the arm
• Visible deformity or a grinding feeling

Most shoulder conditions begin with non-surgical management aimed at reducing pain and restoring function. This may include activity modification, medications, and physical therapy focused on strengthening the rotator cuff and stabilizing muscles around the shoulder blade. For fractures or dislocations, temporary immobilization in a sling may be required.

Surgery is generally considered when conservative care fails or when the injury involves significant structural damage. Common procedures include arthroscopic tendon repair for rotator cuff tears, subacromial decompression for impingement syndrome, Bankart or labral repair for instability, and fixation with plates or screws for displaced fractures. For some conditions, total shoulder replacement or reverse shoulder replacement may be considered.

While some shoulder conditions may not be preventable, taking precautions may help keep your shoulders healthy and strong for years to come.

• Maintain Good Posture: Slouching can narrow the space under the acromion. Keep your shoulders back and down.
• Strengthen the Rotator Cuff: Regular, gentle exercises to strengthen the rotator cuff and the muscles around the shoulder blade can be beneficial.
• Warm Up Before Activity: Always perform a light warm-up before engaging in sports or heavy lifting. This prepares the tendons and muscles for activity.
• Use Proper Technique: Whether you are lifting weights or throwing a baseball, using the correct technique reduces undue stress on the shoulder joint.
• Listen to Your Body: Do not “work through” pain. If an activity causes shoulder pain, stop and rest.

In this post, we explored some of the most common shoulder injuries: rotator cuff tears, impingement syndrome, instability, arthritis, and fractures. Each condition has distinct causes, symptoms, and treatment pathways. In most cases, the initial approach involves conservative, non-surgical methods. These methods include rest, medication, and, most importantly, physical therapy. The decision for surgery is a careful one. It is reserved for injuries that fail to heal with conservative care or for conditions that are inherently unstable. By staying informed and practicing preventative care, you actively take control of your shoulder health.

A subluxation is a partial dislocation. The head of the humerus slips partially out of the glenoid socket and then spontaneously slips back in. A dislocation is a complete separation. The ball comes entirely out of the socket and usually requires a medical professional to put it back in place (reduction).

A reverse total shoulder replacement is a specialized type of shoulder replacement. It is primarily used for patients who have both severe arthritis and a non-repairable rotator cuff tear (rotator cuff tear arthropathy). In a standard replacement, the ball is on the arm bone, and the socket is on the shoulder blade. In a reverse replacement, the positions are switched. This design allows the patient to use the large deltoid muscle to lift the arm, compensating for the non-functioning rotator cuff.

You may experience some discomfort or soreness as you work to regain motion and strength. Your therapist will work within your pain tolerance. They will ensure that the exercises are effective without causing harm. Communication with your therapist about your pain level is important.