I am employed as a truck mechanic and two weeks ago I was turning a heavy wrench and felt a snap in the front of my elbow. I now notice that my biceps muscle seems larger, but it is painful to lift objects or turn a screwdriver and I feel much weaker. Have I simply pulled a muscle?

You have most likely ruptured the distal biceps tendon. This injury is most often seen in males entering their 40's – 50's, especially those employed in heavy labor occupations. It often presents as a sudden “snap or pop” during an episode of heavy lifting or forceful torque with pain along the anterior (front) elbow crease along with progressive swelling and bruising. Often, the individual will notice that the biceps muscle appears larger (“popeye sign”) because the muscle retracts towards the shoulder. After 7 - 14 days, the pain usually subsides, but the individual will often have a noticeable loss of power for twisting activities (i.e. turning a screwdriver or wrench) as well as some decrease in lifting strength.

The biceps muscle attaches near the shoulder at two places but at the elbow only via a single tendon. It inserts into one of the major forearm bones, the radius, and contributes to both elbow flexion and forearm rotation. Specifically, the biceps muscle is the major contributor to forearm supination (i.e. placing the hand in the “palm-up” position) and, therefore, loss of this function will significantly decrease power and endurance for twisting activities. Some studies have shown between a 45 - 65% loss of torsional strength in patients with chronic distal tendon ruptures. Although ruptures near the shoulder are often very well tolerated, ruptures of the tendon distally can result in bothersome weakness in younger individuals.

Treatment for this injury includes both nonoperative care and surgical repair. In older individuals or those persons with less need for forearm torsional power and endurance, avoiding surgery is often preferred.

In younger patients, particularly athletes and/or heavy laborers, and in patients with ruptures in their dominant arm, the loss of strength may be more bothersome and can result in difficulties returning to their chosen profession or hobbies. In these cases, surgical repair may be advocated. Repair of this tendon can be accomplished often with a single incision at the elbow crease using special anchors or implants. The risks of surgery can include motion loss, excess bone formation, nerve injury, and re-rupture. In most recent series using a single incision technique, however, there appears to be a reduction in these risks with most patients regaining nearly normal motion and strength.

If you believe you have sustained such an injury, I would recommend an evaluation by an orthopedist with specialty training in upper extremity surgery since early treatment usually yields the best results.