Humerus fractures can result in functional problems with all joints of the upper extremity, including the shoulder and scapula, the elbow, even the wrist, forearm, and hand.
Rehab should take all of these areas into consideration. Depending on how long the arm was incapacitated, regain of full function can be lengthy. Probably best to spend some time with a or ot. Stick with it. Good luck!