CHECK SHOULDER CLEARANCE BEFORE RIDING
Checking for shoulder clearance is a MUST DO every time you saddle.
Before you set foot in a stirrup.
It should be as ritualistic as tightening your cinch.
The most effective way to make certain your horse has room to operate those beautiful big shoulders while carrying you is to follow the advice in this video. If his/her body has changed, your shim has slipped or you have no shim at all, this will tell you. Fix it before you ride. It can make a big positive difference.