4. Impingement
Any change in the function of the shoulder could indicate impingement. Impingement is a very painful thing that can happen when the upper part of the shoulder puts unusual pressure on the soft tissues within the shoulder, especially when the arm is moved up and away from the body. Someone suffering from impingement might appear as though they are shrugging their shoulders before lifting their arm, but in actual fact, it is the functionality of the shoulder that is causing them to do this, and not the other way round.
As the person lifts the arm on the affected side, the rotator cuff and its bursa and tendons are impinged upon, causing limited movement, discomfort and often a great deal of pain. Sometimes, impingements can be rectified through stretching and with the support of a physiotherapist, however, icing and resting are advisable treatment options in the early stages, as impingement has a nasty habit of leading to bursitis and tendinitis if not managed carefully.