Every once in a great while, I see a question on a forum about how to work the lower Trapezius muscles. Even on the BW-oriented sites, the stock answer involves weight lifting. I remember reading on one of my anatomy books that I studied indicated that the pull-up and chin-up both work the lower traps. Most disagree with me on this.
Last week, someone left me a question about how to make pulls and chins less painful for their rotator cuffs. This got me thinking about the issue of whether or not the trapezius gets any work during doing pull-ups. Take a look at this drawing of the trapezius muscle. Keep in mind that all muscles pull their ends together. They don't push apart.
As you can see, this muscle is responsible for stabilizing the trap. It moves the shoulder blades up, down, and towards the spine. So, if the shoulder blades are going to stay in place while under a load, it's the trap's job to do that (yes, there are other muscles involved but for our purposes, I'm focusing on the trapezius).
Pavel talks about "keeping the shoulders in their sockets" numerous times in his books. This is pretty simple to describe for our purposes: keep your shoulders away from your ears from doing pull-ups. The natural tendency of the shoulder blade is to raise up when we hang our weight from our hands. If we're to keep our shoulder blades down when chinning, then it's going to fall on the trapezius muscles to do it, particularly the lower section.
So, why is everyone under the impression that the traps get no work from the pull-up or the chin-up? People are trying to make the exercise easier, resulting in bad form. You can demonstrate this for yourself on a chinning bar: Dead hang from the bars in both positions that Pavel is demonstrating in that photo. The shoulders-down position is the harder of the two because the traps are firing, trying to retract and hold your shoulder blades under the load of your body. This becomes far more apparent when you watch someone approaching failure when doing pulls or chins. They're trying to make the exercise easier as they tire to get more reps. So, up come the shoulders.
Don't make this mistake when you're chinning. Keep your shoulders down when doing your pulls and chins. This is key for keeping your shoulder muscles strong and keeping your rotator cuff healthy. Weak traps are the first step towards rotator cuff problems. You can get even more work on the traps by drawing your shoulder blades together at the top of the bar, attempting to touch your spine with them. You'll end up with your chest to the bar, as Vince Gironda insisted that all his trainees do. You can get good Trap work from pull-ups and chin-ups. You just have to do the exercise properly.
A closer look at my towel pull-up photo. What's that in the center of my upper back? ;) Note that my shoulders come up enough to allow proper rotation of the scalpula but they're not kissing my ears.