Biceps Anatomy and Function

The biceps muscle is a collection of two muscular bodies (one termed ‘short’ and another ‘long’) which join at the elbow to form a single tendon. This tendon crosses the elbow and attaches to the radius bone in a region termed the radial tuberosity. Collectively, the biceps muscle works mainly as an elbow supinator (the motion involved in turning a screw driver or a door knob) and also an elbow flexor.

One of two components of a biceps tendon may rupture. The long head of the biceps tendon can rupture at the shoulder. This most commonly occurs in suddenly in middle-aged or older individuals. This tendon is most susceptible to injury due to the anatomic course of the tendon. The long head of the biceps tendon attaches to the muscle belly of the lateral (or outer) biceps. As the tendon moves towards the shoulder, it is held in place by a boney indent known as the bicipital groove. Entering the shoulder, the tendon makes a nearly 90 degree turn towards its final attachment on the glenoid labrum. At this 90 degree turn, the biceps is guided by a sling of tissue and one of the rotator cuff tendons – the subscapularis. The long head of the biceps tendon may rupture anywhere along its course. Thankfully, proximal biceps ruptures require no surgical treatment as research studies have shown no deficit in strength or function at 1 year following injury. We believe this to be because the other muscle belly remains attached to the short head of the biceps tendon, thereby preventing complete retraction of the muscle. Despite this, patients will still notice a so-called ‘Pop-Eye’ muscle on one side after injury.

In contrast, the biceps tendon may rupture at the elbow. This injury more commonly occurs in younger individuals and commonly requires surgical repair for optimal results. For more information on distal biceps tendon ruptures, please click here.

 

Work-Up

Patients are often seen first in either the emergency room or their family physician’s office. For any patient with shoulder pain where a fracture has been ruled out, clinical exam will dictate how quickly additional imaging should be considered. If a clinical exam is very highly suggestive of a proximal biceps injury, an ultrasound can be quickly arranged to assess for the possibility of a tendon tear. The diagnosis of a proximal biceps tendon rupture often prompts a referral to an Orthopaedic surgeon, which can occur on a non-urgent fashion.

After being assessed by an Orthopaedic surgeon, an MRI may be arranged. Although the MRI will confirm the proximal biceps rupture, the main purpose of arranging for an MRI is to evaluate for other issues within the shoulder that may explain ongoing pain, discomfort, or functional limitation.

 

Treatment

Proximal biceps tendon ruptures do not require surgical management. Even in young individuals, we do not recommend repair. Simply stated, available evidence suggests the only benefit to surgery in proximal biceps tendon ruptures is a mild to moderate improvement in arm cosmesis. Given the risk of ongoing pain, the possibility of an unsightly scar, and muscular tethering to the skin, we do not recommend, nor perform repairs, for proximal biceps tendon ruptures.

 Physical Therapy

Anyone with shoulder pain, regardless of cause, should be started on a shoulder conditioning program to maintain or improve range of motion while working on strengthening.  This is incredibly important for multiple reasons:

  • Therapy can help avoid shoulder stiffness. After an injury, there is a tendency of the shoulder to stiffen up during the healing processes. This will be made worse if a shoulder is not used. Even if therapy is unable to fully alleviate shoulder pain, it will help maintain motion. We often comment: ‘A painful shoulder I can help with, a stiff and painful shoulder is much more difficult to treat’.
  • Therapy can improve pain. By working on muscular strengthening, posture and shoulder kinematics (how the shoulder moves in space), therapy may be able to allow you to recover from injury faster and prevent future injury.
  • Therapy is Time Dependent. It is intuitive that the quicker someone starts physical therapy, the faster they will recover. What most people realize is that delay in start of physical therapy leads to deconditioning, abnormal shoulder movements, and chronic pain. Immediate therapy can avoid a ‘downward spiral’, where a painful shoulder becomes a deconditioned shoulder, which in turn causes more pain (and so on). Shoulder specialists often cringe when a patient says the phrase “I didn’t want to start physical therapy until I was seen by a surgeon” as we know recovery will likely be longer because of it. With very few exceptions (such as a fracture), therapy should be started as soon as a physician provides a prescription for it!

 

General Therapy Instructions

Please note: this alone does not constitute as a formal referral to a physical therapy. The following guidelines are for non-operatively treated distal biceps tendon ruptures. Therapy should be initiated, conducted and monitored by trained professionals.

  • Stage 1 – Motion: The first goal is to achieve and maintain the maximal amount of range of motion possible, ideally back to pre-injury state. Active and active assisted range of motion of the elbow, shoulder, wrist and fingers is started.
  • Stage 2 – Light Strengthening: To start when 80% of expected range of motion is achieved. Recommend starting with light bands and progress to cables and finally free weights. Focus is on low weight with higher repetition.
  • Stage 3 – Strengthening and Conditioning: This stage involves increasing weight to regain pre-injury strength. Exercises are tailored towards job-specific or sport-specific tasks. Care should be taken to maintain proper form and avoid re-injury.
  • Stage 4 – Maintenance: An often forgotten or neglected component of the rehabilitation program. Exercises from Stage 3 should be incorporated into a weekly fitness regimen with the goal of avoiding re-injury.

 

Notable Challenges

  • Post-Injury Pain: Proximal biceps tendon ruptures are painful, especially in the first two weeks following an injury. Pain does subside, and muscular cramping often resolves by 3 months post injury. Ongoing pain and discomfort within the shoulder beyond 3 months may be related to other structural injuries within the shoulder.
  • Shoulder Stiffness and Weakness: Stiffness around the shoulder is to be expected, especially in operatively managed shoulders requiring post-operative immobilization in a sling. It can take upwards of a year to maximize gains in shoulder range of motion and strength. Physical therapy and ongoing exercises are critical for recovery during this time.
  • Complex Regional Pain Syndrome: a challenging adverse pain response associated with some fractures. Requires time, physical therapy and occasionally medications to treat.

 

Summary of Common Treatment/Rehabilitation Pathway