HOW: Begin by standing at a wall with a band attached at the wrists and a foam roller between your forearms and the wall. The foam roller should line up with the wrist crease at eye level. While pushing out into the band for shoulder external rotation, drive the foam roller up the wall. Reach to the maximum height just before the elbows fully straighten. Slowly return to eye level while continuing with tension into the band.
FEEL: You should feel the outside of the shoulders working at the rotator cuff. You should feel the inner bottom shoulder blades working at the lower trapezius.
COMPENSATION: Avoid shrugging the shoulders. Avoid letting the elbows come in.