Gelenk-Klinik

The rotator cuff is comprised of the group of four muscles and their accompanying tendons that allow us to move our arms. The muscles of the rotator cuff arise from the scapula and attach to the humeral head (top of the upper arm bone) in a cuff-like arrangement that helps to stabilize the shoulder joint. The rotator cuff occupies a very tight space between the humeral head and the acromion (the rigid bony arch of the shoulder blade).

What is shoulder impingement syndrome?

Any condition that causes an excessive and painful narrowing of the space occupied by the various structures of the shoulder is referred to as shoulder impingement syndrome. This sort of painful narrowing typically occurs in the tight space occupied by the rotator cuff between the acromion (the rigid bony arch of the shoulder blade) and the humeral head (top of the upper arm bone). Various inflammatory conditions or existing (abnormal) anatomical structures can crowd the available space under the acromion and cause shoulder pain. These conditions can quickly lead to a certain vicious cycle, whereby inflammation and swelling (e.g. in a rotator cuff tendon or in the shoulder bursa) leads to a further narrowing of the subacromial space, and therefore to further inflammation and swelling.

Range of Motion and Stability

The arm’s tremendous range of motion and the special anatomy of the shoulder joint make it necessary to ensure a precise centering of the humeral head in the shoulder joint. In contrast to other joints in the body that are held in place by a bony assembly (e.g. the pronounced ball socket construction of the hip) and whose range of motion is therefore limited, the shoulder joint is nearly entirely harnessed by soft-tissue components. The tendons that cover the humeral head in a cuff-like arrangement and their muscle extensions act to center the humeral head in the shallow glenoid cavity. Given the narrow space available, preventing these tendons from getting pinched during movement requires optimal positioning.

Causes and Types of Impingement Syndrome

Various factors may play a role in the excessive narrowing of the subacromial space (i.e. the space between the undersurface of the acromion and the rotator cuff). This is why doctors refer to different types of shoulder impingement syndrome.

Shoulder impingement may arise as a result of muscle action that extends into the rotator cuff. While the muscles themselves are essentially healthy, they are not being controlled in the proper manner. Such cases are referred to as functional impingement.

The other forms of impingement are referred to as structural impingement because the excessive narrowing arises in connection with changes in the shoulder bursa or the relevant tendons, bones, and ligaments.

Causes of Structural Impingement

• Thickened or calcified ligaments

• Subacromial spurs

• Wear-related enlargement of the acromioclavicular joint

• Calcified rotator cuff tendon

• Thickened rotator cuff tendon as a result of chronic inflammation

What are the symptoms of impingement syndrome?

The crowding of the tendons under the acromion leads to shoulder pain when you move your arm in certain ways. This is because the movement actually leads to the pinching or tearing of one or more tendons. The result is stress or load-related shoulder pain. This pain tends to be most intense when raising your arm up from your side or to the rear. You may also feel pain on the outside of your upper arm.

Other symptoms may appear as the disorder persists. Irritation of the bursa between the acromion and the rotator cuff tendon often leads to shoulder pain at night and can make it virtually impossible to sleep on the affected shoulder. The shoulder joint’s range of motion may also decrease significantly as the impingement persists. This is referred to as secondary shoulder stiffness or frozen shoulder. The impingement can also lead to prolonged or chronic shoulder pain. This pain can be excruciating, even for less sensitive individuals.

What forms of treatment are available for impingement syndrome?

Various forms of treatment may be considered depending on the cause of the condition. These forms of treatment include a full array of conservative measures, including shoulder massage, physical therapy and thermal therapy. If patients fail to respond to conservative treatments alone, it may be advisable to introduce shockwave therapy. The high-energy sonic waves produced can pulverize calcific deposits and inflamed or necrotic tissue. This then permits their absorption by the body.

If conservative forms of treatment prove ineffective, arthroscopic shoulder surgery may help to eliminate the pinching of the tendons. Arthroscopic shoulder surgery typically aims to expand the available space by shaving and smoothing the underside of the acromion and removing the bursa that is located between it and the rotator cuff.

What about playing sports?

Movements that cause higher levels of stress and that involve a significant extension of the arm such as golf and tennis should be avoided. In the case of all activities, however, the best approach is to let pain be your guide.

Those who are passionate about playing tennis and who can’t bear to stay away from the tennis courts should at least avoid power serving and overhead smashes. They should also consider switching to doubles play.