The biceps brachii is a muscle in the front of your upper arm that connects to the shoulder at two points and to the forearm at one point near the elbow. Its primary actions are bending the elbow (flexion) and rotating the forearm (supination), such as when turning a doorknob. A biceps tendon tear typically occurs when a sudden, powerful load is applied to the already-contracting muscle, often during an eccentric motion where the elbow is forced to straighten against resistance. The consequences of leaving a biceps tendon tear unrepaired depend almost entirely on the location of the rupture, as tears at the shoulder and the elbow result in vastly different functional outcomes.
Anatomy of the Bicep Tear and Acute Symptoms
The vast majority of biceps ruptures (around 96%) involve the long head of the proximal tendon near the shoulder, often due to chronic wear or degenerative changes. Distal biceps ruptures at the elbow are far less common, making up only about 3% of all cases, and typically occur in middle-aged men during a single, forceful event.
The immediate signs of a complete tear include a sudden, sharp pain often described as a “pop” or tearing sensation. This is quickly followed by bruising and significant swelling. When the tendon snaps, the muscle belly recoils, leading to a noticeable bulge known as the “Popeye muscle” deformity, which appears near the elbow for a proximal tear or near the shoulder for a distal tear. While the initial pain is severe, it may lessen significantly after the first few weeks, even without repair.
The Untreated Proximal Tear (Shoulder): Functional and Cosmetic Impact
When the long head of the biceps tendon tears near the shoulder, the injury is often managed non-surgically, especially in older or less active individuals. This is because the short head of the biceps remains attached, and other muscles in the arm, such as the brachialis and brachioradialis, are the primary elbow flexors. The primary long-term consequence of non-repair is the cosmetic change, where the retracted muscle belly creates the visible, rounded bulge in the upper arm.
While patients often retain near-normal elbow flexion strength, some long-term functional changes may be present. Studies suggest that individuals may experience a minimal loss of elbow flexion strength and up to a 20% loss of supination strength compared to the uninjured arm. However, this strength deficit rarely impacts the ability to perform routine daily activities. A more common complaint is muscle fatigue or cramping, particularly during heavy or repetitive lifting and twisting tasks. Furthermore, the remaining tendon stump can sometimes cause chronic pain or irritation within the shoulder joint, especially if the tear is associated with other underlying rotator cuff issues.
The Untreated Distal Tear (Elbow): Severe Functional Loss
The consequences of leaving a distal biceps tendon rupture at the elbow unrepaired are far more serious for arm function. Unlike the proximal tear, a complete distal tear means the entire biceps muscle loses its attachment to the radius bone, severely compromising its ability to act as a supinator and flexor. Therefore, surgical repair is generally recommended for active individuals to regain maximal strength and function.
Without repair, the functional loss is significant and permanent, particularly affecting the ability to powerfully twist the forearm. Individuals treated non-operatively can expect to lose between 40% and 60% of their forearm supination strength. This deficit makes everyday tasks that require a strong twisting motion, like using a screwdriver, turning a stiff key, or pulling on a rope, substantially more difficult. Loss of elbow flexion strength is also considerable, ranging from about 20% to 30% compared to the uninjured arm. The muscle’s retraction can make a delayed surgical repair more complicated or impossible without a tendon graft.
Managing Life and Function Without Surgical Repair
For individuals who choose or require non-operative management, typically those with proximal tears, the focus shifts to maximizing the strength of the surrounding, uninjured musculature. Physical therapy plays a role by concentrating on compensatory strengthening of the brachialis and brachioradialis muscles, which take over the majority of elbow flexion duties.
Long-term management involves adaptations to avoid overstressing the compromised muscle unit. Patients may need to use their uninjured arm for heavier lifting or repetitive twisting motions to prevent fatigue and discomfort. Strengthening the rotator cuff and scapular muscles is also important to maintain overall shoulder stability and function, which helps reduce strain on the remaining biceps tendon components. By adhering to a focused strengthening program and modifying certain activities, many patients can achieve a satisfactory functional outcome despite the permanent anatomical change.