What is the biceps tendon? What does it do?

The biceps tendon is a band of connective tissue that attaches the biceps muscle (think biceps curl) to the shoulder blade in dogs. The tendon is located at the top part of the muscle and runs through the shoulder joint before transitioning into skeletal muscle tissue (biceps muscle) and attaching to the elbow. In dogs its primary function is to flex the elbow (just like in people) and extend the shoulder (not like in people). If you are curious about the differences in human and animal anatomy our human PT canine rehabilitation therapists would be happy to discuss it. 

How do dogs injure their biceps tendons?

Biceps tendon injury is most often an overuse injury, meaning chronic repetitive movements causing microdamage over time. However there are a small number of dogs that have an acute/abrupt rupture or snap of their tendon(s). (These are rare and are usually associated with trauma). Dogs competing or training in agility/fast cat/flyball/etc are at a higher risk for biceps tendon issues due to the repetitive and extreme athleticism required. Dogs who are generally inactive during the week and then are extremely active on the weekends (think multi-mile steep incline hike) are also at a higher risk for biceps problems. This is because the tendon takes up the extra work required when a dog is generally less strong/fit. 

WHAT does it look like and HOW do we diagnose biceps tendinopathy?

The most common presentation is a front leg limp/lameness that comes on slowly and/or can sometimes go away. Often our dogs will get better with rest but then when we do any strenuous exercise they begin to limp again. Sometimes responsive to pain medication but in many cases they are only partially or no better. 

The first step to a diagnosis is the physical exam, there are specific tests that can be performed to isolate the biceps tendon. If these are positive, imaging of the front leg is next. The most common way we image the biceps is with radiographs – most general vet clinics can perform this. It is important to understand that radiographs image bone, since the biceps tendon is a soft tissue structure, they cannot form a perfect picture. Radiographs also ensure additional problems such as shoulder arthritis, elbow dysplasia, bone tumors, etc are not missed.

Ultrasound of the biceps tendon is also becoming more common. This is the best way to get the clearest picture of a possible injury but in most cases requires specialty machines and education. 

What do we DO about it?

As with any soft tissue injury treatment depends on a variety of factors: severity, chronicity, comorbidities, just to name a few. For mildly affected patients especially those without other conditions, rest +/- NSAIDs is usually the first recommendation. In all cases of tendinopathies, slow return to activity with targeted exercises at a rehabilitation clinic is vitally important. Returning to function too fast, especially to the same activity that caused the injury will increase the likelihood of re-injury dramatically. Low activity can be important for multiple weeks as tendons heal slowly. 

Rehabilitation therapy with controlled return to function is essential for optimizing the outcomes of biceps tendinopathy. There are also physical modalities such as intralesional injections, shockwave, laser, PEMF, specialty soft tissue mobilization etc that can speed/help recovery. See other newsletters for more information on these OR ask us at your next session. 

An important side note is that in RARE cases there is a surgical treatment. Further discussion and education can be provided in the event your pet is a candidate**