Only can raise arm halfway unless i lie down, lean way back..then full movement is ok.

Tendon Tear?: Patients with your symptoms sometimes have rotator cuff injuries ranging from tendinitis to a tendon tear. Your loss of strength is worrisome for your having a more significant rotator cuff tendon injury and should be evaluated to determine the diagnosis. After a history and physical exam and relevant imaging, your doctor will be able to make a complete diagnosis and make recommendations.