Dips and muscle ups are exercises that we all know and love… right? Okay, so it’s a love-hate relationship. Either way, we often hear complaints of anterior (frontal) shoulder pain from individuals performing this exercise. They asked us why this could be happening, so here’s a crash-course on how compressive load can result in tendinopathy (tendon issues).
Tendons are bands of tissue that connect muscles to bone. When we contract a muscle in order to move a joint, the muscle pulls on the tendon, which in turn pulls on the bone that it attaches to in order to carry out this movement. This means that tendons must be able to withstand a lot of force – just think about how much tension they’re under when you’re performing a max lift!
The key to picturing compressive load is to understand how tendons attach to bones. Many tendons wrap partially around their respective bone before attaching. This means that when the bone is moved it pulls the tendon tighter against itself. Since the bone is obviously not going to give way, the tendon that is squished against the bone compresses, flattening itself out to accommodate the force of tension.
This is the case while performing dips or the bottom of the muscle up. The long head of the biceps tendon wraps around the head of the humerus before attaching to bone. So when the shoulder is extended backwards during the motion of a dip, the biceps tendon is compressed against the humerus, which may eventually result in tendinopathy.
Although tendons are strong, constant tension and compression will eventually take its toll. The tendon will undergo degenerative changes, meaning a decrease in function and a possible increase in pain. Click the link below to have a look at a video that allows you to get a visual on what we’re describing here (1:20 mark for the shoulder specifically).
One of the most common movement faults we see on video analysis is allowing the humeral head to drop anteriorly at the bottom of the dip/muscle up. Our patient Whitney kindly allowed us to use a clip of her video. She’s been experiencing right anterior shoulder pain at the bottom of the muscle up. You can see on the right shoulder where the head of the humerus “dumps” forward and puts even more compressive load on that long head of biceps tendon.
On her exam, we saw that she had a tight pec on the right and weakness of the inferior traps. We gave her a couple of drills to address both issues. Then we emphasized the need to maintain the shoulder girdle in a more retracted position and thus decreasing the amount of anterior shear on her humeral head. She had to scale back on the exercise a bit by adding a band to support her body weight slightly until she was able to control her shoulder girdle better.
If you have experienced anterior (frontal) shoulder pain while performing dips it’s quite possibly your biceps tendon acting up! Have a buddy video your technique and slow it down to assess your shoulder position at the bottom of the dip and you might find you’re doing the same thing. If you need help assessing come down to our Physiotherapy Clinic and we can help you out.
Cook, J. & Purdam, C. (2011). Is compressive load a factor in the development of tendinopathy? British Journal of Sports Medicine, 46, 163-168
