Shoulder impingement is categorized according to cause and severity as follows:

1. Primary impingement:
   • Caused by anatomical changes such as bone spurs or an abnormal shape of the acromion.
2. Secondary impingement:
   • Due to functional problems, such as instability or muscle weakness.
3. Internal impingement:
   • Mainly affects athletes and is caused by repeated overhead throwing movements. 

The causes of shoulder impingement are varied and include:

• Anatomical changes:
  • Bone spurs or variations in the shape of the acromion narrow the subacromial space.
• Overuse:
  • Repeated overhead work, such as by painters or craftsmen, as well as sports activities like tennis or swimming.
• Degenerative processes:
  • Age-related wear and tear of tendons and bursae, especially of the rotator cuff.
• Muscular imbalances:
  • Weakness of the stabilizing shoulder muscles leads to incorrect movement of the shoulder joint.
• Shoulder instability:
  • Common in young, athletically active people due to overstretching or injuries.

The symptoms of shoulder impingement can vary, but are typically:

• Pain:
  • Especially during overhead movements or lifting the arm to the side. The pain often occurs at night or at rest.
• Movement restrictions:
  • Difficulty lifting the arm above shoulder height.
• Loss of strength:
  • Reduced strength when holding or lifting objects.
• Swelling and inflammation:
  • Accompanying signs of inflammation in the shoulder joint area.
• Grinding or rubbing:
  • Mechanical noises when moving the arm.

The diagnosis is made through a combination of medical history, clinical examination, and imaging techniques:

- Medical history:

- The doctor inquires about the exact location of the pain, the course of the symptoms, and possible triggering activities.

- Clinical examination:

- Tests such as the Neer test or the Hawkins-Kennedy test help to reproduce the symptoms.

- Imaging techniques:

- X-ray: Visualization of bone spurs or shape changes of the acromion.

- MRI: Detailed examination of tendon tears or inflammation of the rotator cuff.

- Ultrasound: For assessing bursitis or minor tendon damage.

Conservative Therapy

Most cases of shoulder impingement can be treated without surgery:

• Physiotherapy:
  • Targeted exercises to strengthen the rotator cuff and improve shoulder mobility.
• Medication Therapy:
  • Nonsteroidal anti-inflammatory drugs (NSAIDs) to relieve pain and inflammation.
• Injections:
  • Cortisone injections into the subacromial space for rapid anti-inflammatory effects.
• Ergonomic Adjustments:
  • Avoidance of overhead movements and optimization of the workplace.

Surgical Therapy

If conservative measures are not sufficient, surgical intervention may be necessary:

• Subacromial Decompression:
  • Removal of bone spurs and expansion of the subacromial space.
• Rotator Cuff Repair:
  • Reconstruction of torn rotator cuff tendons.
• Arthroscopic Procedures:
  • Minimally invasive procedures to treat bursitis or tendon damage.

To prevent shoulder impingement, the following measures are helpful:

1. Regular training: Strengthening the shoulder muscles, especially the rotator cuff.
2. Ergonomic work practices: Avoiding overhead loads and adjusting movement patterns.
3. Warming up before sports activities: Preparing the shoulder for stress through targeted mobilization exercises.
4. Early treatment of shoulder complaints: At the first signs of pain or movement restrictions, consult a doctor in a timely manner.