Epicondylitis, commonly known as tennis elbow when it affects the outer part of the elbow, is a painful condition that develops when the tendons connecting forearm muscles to the elbow become damaged from repetitive use or overload. Despite its popular name, most people who develop this condition have never picked up a tennis racket.

What is Epicondylitis?

Epicondylitis is a condition that affects the tendons in your elbow. Tendons are tough, cord-like tissues that connect muscles to bones. When these tendons become damaged through repeated strain or sudden overload, they develop tiny tears and begin to break down. This process causes pain and tenderness around the elbow area.^[1]

The most common form is called lateral epicondylitis, which affects the outer side of the elbow where muscles that extend your wrist and fingers attach to the bone. The bony bump on the outside of your elbow is called the lateral epicondyle, and this is typically where the pain is most intense. There is also a less common form called medial epicondylitis, or golfer’s elbow, which affects the inner side of the elbow.^[2]

The condition primarily involves damage to a specific muscle called the extensor carpi radialis brevis (ECRB). This muscle helps stabilize your wrist when your elbow is straight. When this muscle is weakened from overuse, microscopic tears form in the tendon where it attaches to the bone. Over time, these tears lead to degeneration of the tendon rather than inflammation, although some swelling can occur during the healing process.^[3]

Epidemiology

Epicondylitis is one of the most common reasons people seek medical care for elbow pain. The condition affects between one and three percent of adults in the general population each year. This means that in the United States alone, millions of people experience this painful condition annually.^[3]

The condition affects men and women equally, showing no gender preference. Most people who develop epicondylitis are over 40 years of age. This is because aging tendons become more vulnerable to repetitive stress and have a harder time healing from minor injuries. The natural wear and tear that accumulates over decades of use makes middle-aged and older adults particularly susceptible.^[3]

Interestingly, tennis players make up only about 10 percent of all people diagnosed with this condition. However, among tennis players themselves, about half will develop elbow pain at some point, and roughly 75 percent of those cases represent true epicondylitis. This shows that while the condition is associated with racquet sports, it affects a much broader population.^[3]

People in certain occupations are at higher risk. Studies have shown that auto workers, cooks, butchers, plumbers, painters, and carpenters develop epicondylitis more often than the general population. The repetitive movements and weight-bearing activities required in these jobs contribute to the development of the condition.^[2]

Causes

The primary cause of epicondylitis is repetitive strain from activities that involve loaded and repeated gripping or wrist extension. When you perform the same motion over and over again, especially while holding or gripping something, it creates continuous stress on the tendons. Over time, this repetitive stress exceeds the tendon’s ability to repair itself, leading to damage and pain.^[3]

The ECRB muscle is particularly vulnerable because of its position in the body. As your elbow bends and straightens during normal activities, this muscle rubs against bony bumps on the elbow. This constant friction causes gradual wear and tear of the muscle over time. Think of it like a rope rubbing against a sharp edge repeatedly until it begins to fray.^[2]

In some cases, epicondylitis can result from a single traumatic event rather than gradual overuse. A sudden strain applied to the arm, such as lifting something very heavy or catching yourself during a fall, can cause immediate tears in the tendon. However, this acute injury pattern is less common than the gradual onset associated with repetitive use.^[3]

Activities that commonly lead to epicondylitis include playing tennis or other racquet sports, where the backhand stroke places significant stress on the elbow. Other risky activities include playing musical instruments, using hand tools like screwdrivers or hammers, typing on a computer for extended periods, and manual tasks like painting walls or sewing. Even carrying a briefcase every day or toting heavy shopping bags can contribute to the development of this condition.^[4]

Risk Factors

Several factors increase your likelihood of developing epicondylitis. Age is a significant risk factor, with the condition being most common in individuals between 35 and 54 years of age. As we age, our tendons become less flexible and more prone to injury, making it harder for them to withstand repetitive stress.^[3]

Smoking is another important risk factor. Tobacco use affects blood flow throughout the body, including to the tendons. This reduced circulation impairs the tendon’s ability to heal and maintain healthy tissue. People who smoke are more likely to develop epicondylitis and may experience slower recovery times.^[3]

Obesity also increases risk. Extra body weight can alter your posture and the way you move, potentially putting additional strain on your elbows during everyday activities. Additionally, the metabolic changes associated with obesity may affect tendon health and healing capacity.^[3]

Repetitive movements for at least two hours daily significantly raise your risk. This explains why certain occupations are particularly associated with the condition. If your job or hobby requires you to repeatedly twist your wrist, extend your wrist against resistance, or grip objects for extended periods, you’re more susceptible to developing epicondylitis.^[3]

Vigorous activity that involves managing physical loads over 20 kilograms (about 45 pounds) on a regular basis is another risk factor. Lifting heavy objects, especially when combined with twisting motions, places enormous stress on the elbow tendons. This is why manual laborers and construction workers often develop this condition.^[3]

For athletes, poor mechanics and technique or using improper equipment can precipitate the condition. In tennis, factors like incorrect grip size, inappropriate string tension, or improper swing mechanics can contribute to injury. The stress is greatest on the outer elbow of the dominant arm during a backhand swing.^[3]

Symptoms

The main symptom of epicondylitis is pain on the outside of the elbow. This pain typically develops gradually over time, starting as mild discomfort and slowly worsening over weeks or months. In most cases, there is no specific injury that patients can point to as the beginning of their symptoms. The pain just seems to appear and progressively get worse.^[1]

The pain is usually sharp or has a burning quality to it. It can range from mild discomfort when you move your arm to constant pain that affects your sleep at night. Many patients describe the pain as traveling from the outside of the elbow down into the forearm and sometimes extending all the way to the wrist.^[4]

The pain typically worsens with certain activities. Lifting or bending your arm, especially with your palm facing downward, often triggers discomfort. Gripping objects, moving your wrist, or twisting movements can all make the pain more intense. Simple daily activities like turning a doorknob, holding a coffee cup, shaking hands, or opening a jar can become surprisingly painful and difficult.^[1]

Weakness is another common symptom. You may notice that your grip strength has decreased. This isn’t necessarily because your muscles are weaker, but because the pain prevents you from gripping with full force. Some people find they start dropping things or have difficulty holding objects, particularly when reaching for items or when their arm is extended.^[1]

Tenderness or swelling in the elbow area may be present, although significant swelling is uncommon. When a healthcare provider examines you, pressing on the area just below the bony bump on the outside of your elbow will typically cause significant discomfort. Some patients also report difficulty fully straightening their arm.^[4]

The symptoms are often worse when your forearm muscles are active. Resistance against wrist extension, meaning someone pushing down while you try to lift your hand upward at the wrist, will usually reproduce or worsen the pain. This is a classic sign that healthcare providers look for when diagnosing the condition.^[3]

Prevention

Preventing epicondylitis involves modifying how you use your arms and making adjustments to reduce repetitive strain. If you play racquet sports, ensuring proper technique is crucial. Working with a coach to improve your swing mechanics, particularly your backhand, can significantly reduce stress on your elbow. Consider having your equipment evaluated to ensure your racquet has the right grip size and string tension for your needs.^[3]

For work-related prevention, pay attention to your posture and hand positioning. If you type frequently, make sure your keyboard and mouse are positioned so your wrists remain in a neutral position. Take regular breaks to rest your arms and hands, especially if your work involves repetitive motions. Avoid holding objects away from your body or below your waist, as this position places extra strain on the elbow tendons.^[4]

Strengthening exercises for your forearm muscles can help prevent the condition. Building muscle strength and endurance allows your tendons to better withstand the demands placed on them. Simple exercises that involve bending and straightening your arm, along with gentle wrist movements, can be beneficial. However, these should be done carefully and without causing pain.^[4]

Avoiding activities that cause pain is essential. If you notice elbow discomfort during or after certain activities, modify or reduce those activities before the problem becomes more serious. Early intervention when you first notice symptoms can prevent the condition from progressing to a chronic, debilitating state.^[4]

Using proper lifting techniques helps protect your elbows. When lifting objects, keep them close to your body and avoid twisting movements. If you must perform repetitive tasks, try to alternate between different activities to give specific muscle groups a chance to rest.^[5]

For those at high risk due to occupation, using supportive equipment may help. A forearm strap or wrist brace can reduce stress on the tendons during activities. These devices work by distributing forces across a broader area rather than concentrating stress at the tendon attachment point.^[4]

Pathophysiology

The underlying mechanism of epicondylitis involves degeneration of the tendon tissue rather than true inflammation. This is an important distinction because it affects how the condition should be treated. The medical term for this process is tendinosis, which refers to the chronic breakdown of collagen within the tendon. While some inflammation can occur, especially during acute flare-ups, the primary problem is the structural deterioration of the tendon itself.^[2]

When you repeatedly use the muscles that extend your wrist and fingers, you create continuous mechanical stress on the ECRB tendon where it attaches to the lateral epicondyle. This stress leads to microscopic tears within the tendon tissue. Normally, these tiny tears would heal through the body’s natural repair processes. However, when the rate of damage exceeds the rate of repair, the tears accumulate and the tendon begins to degenerate.^[2]

The degeneration involves a breakdown of the normal collagen structure within the tendon. Collagen is the protein that gives tendons their strength and flexibility. As the collagen breaks down, it is replaced with disorganized tissue that is weaker and less able to withstand stress. This abnormal tissue also contains an increased number of blood vessels and nerve endings, which may contribute to the pain experienced by patients.^[3]

The anatomical position of the ECRB tendon makes it particularly vulnerable to this type of injury. The tendon passes over the bony prominence of the lateral epicondyle. Every time you bend and straighten your elbow, the tendon moves across this bony surface. This constant rubbing creates friction that contributes to wear and tear. Additionally, the ECRB helps stabilize the wrist during activities when the elbow is straight, putting it under considerable tension during many common movements.^[2]

Another factor in the pathophysiology is the relatively poor blood supply to tendons in general. Tendons have fewer blood vessels than muscles, which means they receive less oxygen and nutrients. This limited blood supply slows the healing process and makes tendons more susceptible to degenerative changes. When you add repetitive stress to an already vulnerable structure, the conditions are ripe for the development of chronic problems.^[5]

The pain experienced in epicondylitis likely results from multiple factors. The microscopic tears in the tendon stimulate pain receptors. The abnormal tissue that replaces healthy collagen contains more nerve endings than normal tendon tissue. Additionally, when you use the affected arm, the damaged tendon cannot properly distribute forces, leading to excessive stress at specific points that triggers pain signals. The weakness many patients experience isn’t due to actual muscle weakness but rather to pain inhibition. Your brain limits muscle activation to protect the damaged tendon from further injury.^[3]