Again, we are seeking movement in our shoulder blades. We want them to have a good glide on the back of the ribcage.

So this exercise it about hiking those shoulders up and pulling them back down again. Our "hiking up" muscles are usually rock stars.

Upper traps and levator scapulae have a ton of practice. It's really our "shoulder depression" muscles that need to brush up their skills a bit. Namely the middle and lower trapezius, the serratus anterior.