A request was made by a poster for me to write a blog covering biceps tendinitis. This is actually a fairly complicated topic with quite a bit of controversy, but I’ll do my best to share some basic info that hopefully TD peeps will find interesting. There are some technical parts, so apologies for that, but I do think a basic understanding of the anatomy is helpful.
Question 1: What is the biceps, exactly?
The biceps is a muscle that we are likely all familiar with, lying in the front of the upper arm and used to perform curls and similar exercises. The word ‘biceps’ has a Latin origin meaning ‘two heads’. This describes the upper (or proximal) end of the biceps where there are two tendon attachments.
The first is the long head of the biceps which attaches to the labrum at the top of the socket in the shoulder. It then curves over the top of the ball (humeral head) where it exits the shoulder joint and begins its course down the front of the upper arm bone (humerus). At the front of the shoulder joint, it travels through what is called the ‘bicipital groove’ which is an area of the bone of the humerus between two bumps (called tuberosities). This groove is often the site of issues in pitchers (more on this below).
The second is the short head of the biceps, which originates from a bony projection off the shoulder blade in the front of your shoulder called the coracoid. It travels straight from here to meet up with the long head of the biceps in the upper 1/3 of the arm. There, the tendons join and form the biceps muscle.
Below this (distally), the muscle turns back into a tendon just above the elbow and a single tendon then travels down to one of the bones of your forearm (called the radius) where it attaches at a bony prominence called the radial tuberosity.
Question 2: How is this tendon involved in throwing?
This is a great question, and a subject of much debate amongst experts. The short head of the biceps likely has a relatively insignificant role in throwing. The long head (which is the one that attaches inside the shoulder joint) is much more involved in the throwing motion. When throwing at MLB speeds, the shoulder rotates at 7000 degrees per second, which is the fastest known human motion. One can imagine the stress this places on the structures that surround the shoulder.
Without delving into the weeds too much, it seems as though the biceps has a role in position sense of the shoulder during throwing, likely a role in stability of the shoulder joint and also helps slow down the arm after ball release.
At the other end of the tendon (distal), the elbow changes rapidly from a bent position to a straight position as the ball is released during a throw. In order to keep the bones of the elbow from jamming into each other at a high speed, the biceps muscle fires to slow down this elbow straightening (what we call an eccentric contraction). This allows some of the force of throwing to be dissipated by the muscle (kind of like a shock absorber).
If it seems like that is a lot of jobs for a small tendon/muscle- it’s because it is…
Question 3: What happens when someone gets biceps tendinitis?
Tendinitis is a fairly broad term and can mean a number of different things depending on the context. With respect to the biceps, a thrower can develop issues at either the upper (proximal) or lower (distal) end of the biceps. The suffix -itis means inflammation, so the general thought is that there is inflammation that develops in or around the tendon.
The reasons ‘why’ are heavily debated, but generally there is probably some combination of overuse/fatigue and altered mechanics or muscle imbalances that contribute. It takes a tremendous amount of efficiency of motion and coordination of muscle movements to throw a baseball in excess of 90mph, and any small abnormality can easily be compounded by the sheer number of repetitions and intensity of a typical pitcher. Over time, this can add up to cause damage to the tendon and result in inflammation and pain.
Arthroscopic image of normal biceps tendon (left) and inflamed biceps (right)
Question 4: How does the player/medical staff separate this injury from other issues that can seem very similar?
This can be VERY difficult. Often the player will have pain at the front of the shoulder (in cases of proximal biceps tendinitis) or just above the elbow (in distal cases). A thorough history and exam is performed in order to hone in on the likely problem area.
An MRI is ordered in some cases. One of the challenges with this type of issue is that in many cases, an MRI of a pitcher already has some abnormalities on it which are likely adaptive and have been present for a long time (and are not the actual cause of pain). In addition, in many cases the inflammation around the bicep isn’t something that can be clearly seen on MRI. So interpreting imaging studies can be a significant challenge.
Usually the exam is (in my experience) the most helpful thing in recognizing biceps tendinitis when it is present. The athlete is usually tender right in the area of the tendon, which is a helpful finding.
Question 5: Once a pitcher is diagnosed with biceps tendinitis, how are they treated?
Again, there are a lot of variables here. But presuming it is significant enough to affect the performance of the pitcher, they would typically be shut down for a period of time to prevent worsening of the condition. Anti-inflammatory medication may be used. In some cases, injections of cortisone are used to try and decrease the inflammation.
With the recent increases in the use of technology, video may be consulted to see if there have been subtle mechanical changes which may have contributed to the issue. Muscle strength can also be tested in various areas around the shoulder to see if weakness is contributing.
In essentially all cases, a rehab program will begin that is likely to include strength and flexibility components. When the pain has subsided, a return to throwing program is begun and once complete, the athlete can return to play.
A group out of Mayo Clinic (led by Dr. Chris Camp) recently did a study of pro baseball players (minor and major league) and causes of injury over a several year period. Tendinitis of the proximal biceps was actually the #4 cause of injury with an average return to play time of about 22 days.
Question 6: Is surgery ever needed?
It is quite uncommon for surgery to be needed for this issue. In fact, in Dr. Camp’s study above surgery was only required in 3% of cases of proximal biceps tendinitis. So clearly most of these cases improve with non-surgical treatment. In addition, surgery for this particular issue has a fairly poor track record and is avoided if at all possible.
Question 7: What can be done to prevent biceps tendinitis?
Great question, reader. If I knew the answer, we could likely both be millionaires given how common this injury is and the dollar figures involved when a high-priced starter or reliever is on the shelf for this reason.
Generally, I believe monitoring the workload of pitchers through the season, doing what you can to ensure they maintain a good off-season program and having a good line of communication with the players are all important. As video analysis and other analytic measures become more popular, my hope is that they can be incorporated into injury prevention as well.
Thanks for humoring me on this complex topic. Please feel free to add a request for a future subject in the comments. GO TWINS!!