As we talked about last week (read here), shoulder pain is all too common, especially with repetitive overhead activity and reaching behind the back. It’s typically seen in overhead sports like swimming, volleyball, tennis, and baseball pitchers along with professions such as carpenters, painters, and electricians. These repetitive movements often lead to a condition known as shoulder impingement syndrome where there’s reduced space between the acromion (top of the shoulder blade) and humerus (upper arm) which creates “pinching” on the surrounding tissues.
Normally, the subacromial space, or the space between the acromion and humerus is cushioned by the subacromial bursa. This fluid-filled sac allows the supraspinatus tendon (one of four rotator cuff muscles) to glide back and forth underneath it with elevation of the arm without irritating the tendon. The subacromial space is also maintained by all four rotator cuff muscles working together to stabilize the glenohumeral (shoulder) joint so the shoulder can move through its full range of motion without pain.
Repetitive overhead and reaching behind the back movements (elevation and internal rotation) can lead to reduced subacromial space over time and impinge, or “pinch” on the supraspinatus tendon and other surrounding tissues creating pain because they have nowhere to go. This can then lead to other shoulder problems such as; rotator cuff tendinitis or tendinosis, subacromial bursitis, biceps tendinitis, rotator cuff tear, and labral issues.
However, the majority of shoulder impingement cases respond favorably to conservative treatment by addressing joint and soft tissue restrictions in the office along with home exercises that are just as, if not more important to stick with. It’s a team effort between the patient and doctor!
One final note: a reduced subacromial space can also be due to a few other factors. These include A/C joint degeneration, aging, bone spurs, and the actual shape of the acromion bone.
Just remember, aging and some degeneration or bone spurs doesn’t necessarily mean a person will have pain or it’s the reason they are currently in pain!