Rumor has it that every back muscle works incredibly hard when you deadlift. Well, it’s not a rumor. It’s true. Even your rear deltoids are involved in the lift when you are actively trying to keep the barbell as close to your body as possible. Most of the work done by the bacк is isometric.
The role of the trapezius muscle (traps) is to keep the upper back area rigid so that the force generated by the hips can be transmitted to the bar. When you deadlift, the spine acts as a human crane. The traps and the rest of the upper back musculature stabilize the upper portion of that crane. The contraction is mostly isometric. You are not supposed to perform a shrugging motion.
Static vs. Concentric Contraction
In general, exercises with a larger range of motion tend to build more muscle.
What do you think will produce more shoulder mass – the planche or the overhead press done with a full range of motion?
I know that some of the gymnastic revivalists will choose the planche, but if somebody was holding a gun to my head and threatening to kill me unless I make my shoulders as big as possible, I wouldn’t rely on planche anything. Full contraction often (not always) beats statics when it comes to muscle growth.
The Spinal Erectors Are The Most Important “Deadlift” Muscles
The traps are thick and have short insertions. They recover quickly and represent one of the toughest muscle groups in the whole body. The real deadlift heroes, however, are the spinal erectors – the muscles that run along the spine.
The spinal erectors never get invited to beach parties. Similar events are reserved for the arms, chest and lats. Who gives a fuck about spinal erectors? What’s that?
You will never meet a decent deadlifter who does not have developed spinal erectors. I often talk bad about the deadlift, but even I have to admit that it has built my spinal erectors considerably compared to my previous insect state.
Another very important reason why the spinal erectors always grow from heavy deadlifts is that their range of motion is pretty decent during deadlifts. A large part of the deadlift is essentially a back hyperextension.
To summarize:
The deadlift will certainly build your traps, especially the middle part, but if your goal is to have “big fucking traps”, you may consider dedicated exercises such as heavy barbell or dumbbell shrugs, rowing variations, overhead presses (the shrug at the top works the traps intensely), neck training and other forms of trap assaults. Conversely, if you want thicker and stronger spinal erectors, the deadlift is hard to beat.
P.S. The post on natural potential has been updated.