Shoulders are great when they move your arms freely like when combing your hair, scratching your back or raising your arms. However, when nerves get irritated or muscles go into spasm then it can quickly become uncomfortable to raise your arm, throw a ball or even sleep on your side at night. Specific shoulder conditions like a frozen shoulder or rotator cuff tears are common these days especially for anyone who does repetitive motion in their jobs. People like painters, carpenters pounding nails or even desk worker who compute all day are at risk for developing shoulder problems.