One of the most common shoulder pain discomfort/injury experiences related to non-traumatic, ergonomic causes is called “impingement” syndrome.
Shoulder impingement syndrome is persistent shoulder pain that affects everyday activities. The space in the shoulder where the rotator cuff tendons, muscles and bursa pass through is very narrow and is known as the subacromial space. This space is reduces when you raise your arm.
You may notice that you often have weakness when you raise your arm to the side, most commonly with palm down, caused by a tendon being pinched in your shoulder. With repetition, inflammation may occur, with gradually increasing symptoms.
Frequent examples seen in the clinic have occurred because the client has been in an exercise program lifting weights with arms out to the side, palms down. At the computer, it is common when the individual is sitting with the keyboard and mouse elevated on a standard height work surface, causing elbows to be raised, resting on the elevated surface, reaching for the mouse. Another example includes workers lifting large awkward objects with elbows elevated to the side, i.e., lifting sheet rock, painting a wall with arm away from body (elbows elevated to the side of the body), or frequently reaching for a phone placed to the side.
Reaching with the elbow in front of the body, turning to face an object, lowering a keyboard and mouse surface and exercising with palms up (or avoiding arms out to the side) will reduce the risk for impingement syndrome.