Biceps Tendinitis

The biceps muscle has two tendons that attach it to the shoulder—the long head and the short head—and one that connects it to the radius bone at the elbow. Biceps tendonitis most often involves the long head, which runs through the shoulder joint and attaches to the top of the shoulder socket (the glenoid). When this tendon becomes inflamed due to irritation or microtears, it causes pain and tenderness in the front of the shoulder.

Over time, untreated inflammation can lead to tendon degeneration (tendinosis), partial tearing, or in severe cases, rupture. Biceps tendonitis often coexists with other shoulder conditions such as rotator cuff tears, impingement, or labral injuries, as these issues frequently develop together due to similar stress patterns in the shoulder joint.

Pain in the front of the shoulder is the primary symptom of biceps tendonitis. This discomfort may radiate down the upper arm and worsen with overhead or lifting motions. Common symptoms include:

• Pain and tenderness in the front of the shoulder, especially when lifting or rotating the arm
• A dull ache that may worsen with activity or at night
• Weakness when lifting objects or reaching overhead
• A snapping or popping sensation in the shoulder during movement
• Occasional swelling or warmth around the front of the shoulder joint

In advanced cases, a visible bulge in the upper arm, known as a “Popeye muscle,” may appear if the tendon ruptures and the muscle retracts downward.

Biceps tendonitis is commonly caused by repetitive overhead motion or heavy lifting that strains the shoulder joint. Over time, small tears and inflammation develop in the tendon. Frequent causes include:

• Overuse injuries: Sports involving repeated overhead motions, such as baseball, swimming, or tennis, place constant strain on the tendon.
• Age-related wear: Tendons lose flexibility and strength with age, making them more prone to inflammation and tearing.
• Shoulder impingement: Narrowing of the space between shoulder bones can pinch the tendon, leading to irritation.
• Rotator cuff injury: A weakened or torn rotator cuff changes shoulder mechanics, placing additional stress on the biceps tendon.
• Poor posture: Forward head or rounded shoulder posture increases shoulder strain and tendon friction.
• Trauma: A fall or direct blow to the shoulder may cause sudden inflammation or tearing.

Several factors increase the likelihood of developing biceps tendonitis. These include repetitive overhead activity, age, poor biomechanics, and participation in certain sports or occupations.

• Athletic risk: Overhead athletes such as pitchers, volleyball players, swimmers, and weightlifters are at higher risk due to repetitive shoulder movement.
• Occupational risk: Jobs requiring frequent lifting or overhead work—such as construction, painting, or warehouse labor—can cause chronic tendon strain.
• Anatomical factors: Shoulder instability, joint misalignment, or muscle imbalances can alter tendon movement, increasing friction and irritation.
• Degenerative risk: As tendons lose elasticity with age, they are more susceptible to microtears. Degenerative joint conditions, such as arthritis, can further contribute to tendon inflammation.
• Associated shoulder conditions: Biceps tendonitis often occurs alongside other shoulder issues, including rotator cuff disease, bursitis, or labral tears, which can intensify pain and limit mobility.

Diagnosis of biceps tendonitis begins with a thorough medical history and physical examination by an orthopedic specialist. Dr. Collon will assess the location of your shoulder pain, movement limitations, and any aggravating activities, often performing specific tests to evaluate tendon integrity and pain response.

Imaging studies may be ordered to confirm the diagnosis and rule out other conditions. Ultrasound can visualize tendon inflammation or partial tears, while MRI provides detailed views of the biceps tendon and surrounding shoulder structures such as the rotator cuff and labrum. A precise diagnosis allows for an individualized treatment plan focused on reducing inflammation, restoring mobility, and preventing further injury.