One of the common causes for shoulder pain is rotator cuff injury or impingement of the tendons (subacromium impingement syndrome). This group of muscles stretches from the shoulder blade to the upper arm and is important for shoulder stability. Often due to trauma or posture the muscles and tendons can be damaged resulting in inflammation and pain. The tendons of the rotator cuff muscles go through a space under and can easily be compromised if the shoulders are rounded forwards, or with repetitive throwing activities for example. This can lead to tendonitis, which causes painful movement of the shoulder. With impingement patients often experience difficulties lifting their arm above the shoulder level – as reaching above or combing hair
Another common condition is a tear in the soft cartilage that surrounds and cradles the upper arm bone (humerus) in the shoulder joint (Glenoid labral tear / SLAP lesion). This often occurs due to a fall on an outstretched arm, direct blow to the shoulder, sudden pull, as in lifting a heavy object, or a violent overhead stretch. One can then experience pain, instability in the shoulder and loss of strength.
The joint between the shoulder blade and the clavicle (acromioclavicular joint) is very important for being able to lift or rotate the arm. This joint can have wear and tear that can cause sharp pain in the front of the shoulder. Often people who experience this are athletes, which had falls on the shoulder, people who work overhead, or weightlifters. Degeneration of the acromioclavicular joint can also be caused by a previous dislocation.
Dislocations and subluxations can also occur to the humerus when having a heavy fall on the arm. The shoulder is one of the easiest joints to dislocate, due to the very shallow joint socket. Even after the 12-16 weeks needed for recovery, many of the ligaments and muscles still remain strained and lax and if not addressed can cause long-term complications and increased risk for another dislocation.
The movement of the shoulder blade on the thorax occurs by gliding. Sometimes this gliding can become less and less smooth until what is called ‘snapping scapula’ occurs. This happens after repetitive strain of the muscles of the back and shoulder that causes the shoulder blade to ride more closely to the ribs and cause the snapping sounds and discomfort. It can also be caused by inflammation of the bursa, the fluid-filled sac under the shoulder blade or improper balance of the whole shoulder girdle.
Shoulder problems are commonly occurring because or together with neck problems, due to the neurological, muscular and joint connections. Most of the times if one experiences pain in the shoulder soon the neck starts to hurt or vice versa. Sometimes pain in the shoulder is solely due to a neurological connection and actually the pain is being referred from the neck.