Distal Biceps Tears: More Common Than You Think
⌚️ read time: 6.8 minutes
Distal biceps tears are one of the more traumatic tendon injuries I treat in my practice. And while most people have heard about rotator cuff tears in the shoulder, they're often surprised to learn that the biceps can actually tear right off the bone near their elbow too.
In fact, this injury is so common that most of us can usually diagnose it before the patient even gets to the exam room — patients are typically muscular men in their 40s or 50s, holding their heavily bruised arm slightly bent, telling me about the "pop" they felt while trying to catch or lift something heavy.
Note: This article is specifically about distal biceps tears, meaning a tearing of the biceps away from the bone at the elbow. Patients can also sustain proximal biceps tears, meaning a tearing of the biceps away from the bone at the shoulder. The latter is typically much less detrimental to function (hint: there are duplicate biceps tendons proximally and only one distally) when compared to distal biceps tears.
What Actually Happens?
Your biceps muscle does two main things.
It helps you bend your elbow (duh, you knew that) and
More importantly, it helps you rotate your palm up (did you know that one though?). This motion is called supination.
Why is supination more important, you ask? It’s all about back up plans when the biceps goes missing.
There’s a much bigger, stronger muscle in your upper arm called the brachialis that actually does most of the work bending your elbow. Your biceps just sticks out a bit to assist the brachialis and make you look better at the beach.
But supination?
The biceps is the primary driver of this motion. There are a couple muscles in the forearm that help with this motion too, but if you lose your bicep, you’ll lose about half your supination strength.
In a normally functioning arm, the biceps muscle connects to your forearm via a strong tendon (your distal biceps tendon) that attaches to one of your forearm bones (the radius bone).
For those of you paying attention, yes, this is the same radius bone that is the most common fracture we treat. I’ve covered these fractures extensively in previous articles. But those injuries occur at the opposite end of the forearm (distal radius fractures), rather than the elbow side of the radius where the biceps tendon attaches.
When the distal biceps tendon tears, it usually happens during one specific type of action — trying to resist something heavy as your elbow is forced from a bent to a straight position. This is called an eccentric force and it’s a recipe for disaster.
Think about trying to catch a heavy falling object, or when someone suddenly pulls hard on something you're holding. Classic examples I see all the time include carrying a heavy TV down the stairs (the weight shifts unexpectedly and as you lunge to catch it…POP) or the bottom of a way-too-heavy set of preacher curls in the gym.
How Do You Know If You Have One?
Most patients describe hearing or feeling a "pop" in the front of their elbow, followed by pain and weakness. Within a few days, you might notice an incredible amount of bruising on the inside of your elbow and a change in how your biceps muscle looks. It often bunches up toward your shoulder, creating what we call a "reverse Popeye" sign.
In addition to testing your strength in the office, I will also perform what’s called the ‘hook test.’ It’s far less fancy than it sounds. I will literally try to hook my finger under the tendon when your elbow is bent and palm is facing up. If I can’t, that's a strong (though believe it or not, it’s not 100% accurate) sign your tendon has torn off.
Go ahead, look at your elbow now and try it yourself!
Why Does This Matter?
As I alluded to above, we strongly consider how loss of this tendon might affect your future function. This is true with any injury, really. If you lose the function of the distal biceps tendon, you should expect to lose:
50% of your sustained supination strength
20-30% of your elbow bending strength
The normal visual look of your biceps (it will always remain a little bunched up)
Think about all the times you need to rotate your palm up during the day - turning doorknobs, using tools like screwdrivers, or even starting your car. That's why these injuries can be so frustrating for active people who need their full arm strength.
Everybody immediately worries about their lifting strength, but I find it to be my primary job to clue them in on the supination consequences.
The Treatment Decision
Here's where timing becomes crucial. If you want to surgically repair the tendon (which most active people do), it’s best to have it done within 2-3 weeks of the injury.
If we wait too long, what could have been a straightforward repair becomes much more complicated. Meaning, a much bigger surgery that involves scar tissue, retracted tendons, and oftentimes the need to use cadaver tendon replacement.
The outcomes are not nearly as good.
So if there’s any part of you worried that you ruptured your biceps tendon, please get it checked out right away. The clock is definitely ticking.
The other interesting part of this? Not everyone needs surgery.
If you're not terribly active, we’ve actually found that most people can reasonably acommodate to some permanent loss of strength. The inability to generate high supination forces ends up being annoying at times, but certainly not detrimental in many people.
What About Recovery?
If you choose surgery, expect to be in a splint for a couple weeks, followed by a careful physical therapy program. Most people can start gentle movements right away, but it takes about 3-4 months before you're back to unrestricted activities.
The good news? With proper treatment, the vast majority of patients get back to excellent function after this surgery.
Modern surgical techniques have made this a very reliable procedure. We can now fix these tendons through small incisions with specialized implants that allow for early movement and excellent healing.
But remember — timing is everything. The longer you wait, the harder it becomes to get a great result.
Takeaways:
Distal biceps tears are common injuries that significantly affect both turning and bending strength in your arm
Early diagnosis is crucial - if surgery is needed, it should be done within a couple weeks of injury
With proper treatment, most patients return to full activities, but missing the treatment window can mean permanent weakness
Whether you're a weekend warrior or someone who relies on their arm strength for work, knowing when to get help for a distal biceps tear can make all the difference between a fixable problem and a permanent one.
And if you dare, there are plenty of videos on YouTube of people rupturing these in the gym. But don’t say I didn’t warn you. They’re hard to watch.
