Shoulder Impingement

Shoulder impingement happens when the tissues in your shoulder become swollen and pinch against nearby bones. This can cause pain when you lift your arm or reach overhead. It’s often caused by overuse, injury, or wear and tear as you age. Common symptoms include shoulder pain, weakness, and difficulty moving your arm. Treatment usually involves rest, physiotherapy, pain relief, and sometimes surgery. Understanding the causes and types of shoulder impingement can help you manage and prevent it.

What is shoulder impingement? 

Shoulder impingement occurs when the outer edge of your shoulder blade, known as the scapula, rubs and pinches your rotator cuff underneath it. This condition, also called impingement syndrome, causes pain during movement due to the rubbing or pinching within your joint. 

The rotator cuff, a group of four muscles and their tendons connecting your shoulder blade to your upper arm bone (humerus), is essential for raising and rotating your arm. However, it sits in a narrow space between the humerus and the acromion (the top part of your shoulder blade), making it prone to being pinched. 

If you experience ongoing shoulder pain or difficulty moving your shoulder, it’s important to consult a healthcare provider for proper assessment and treatment.

Types of shoulder impingement 

Shoulder impingement can be classified into specific conditions. Key types include:

• Rotator cuff tendinitis - inflammation of your rotator cuff tendons due to overuse or injury, causing swelling that reduces joint space.
• Shoulder bursitis - inflammation of your bursa (fluid-filled sac) between the rotator cuff and acromion, leading to discomfort and limited movement.
• Acromion deformity - variations in acromion shape, such as being hooked or curved, or the presence of bone spurs can pinch the rotator cuff tendons, causing impingement.

Symptoms of shoulder impingement 

Common symptoms of shoulder impingement include:

• Pain

• Typically felt at the top, front, or side of your shoulder.

• May radiate from the front of your shoulder to the side of your arm.

• Often worsens during certain movements like raising your arm above your head, lifting or lowering your arm, or reaching behind your back.

• Can become more intense at night, interfering with sleep.

• Tenderness

• Your shoulder may feel tender to the touch, especially in the areas affected by swelling or inflammation.

• Weakness

• Difficulty lifting or holding weight with your affected arm.

• Reduced ability to perform tasks requiring shoulder strength, such as dressing, washing hair, or putting on a seatbelt.

• Reduced Range of Motion

• Pain or stiffness that limits shoulder movement, especially when attempting overhead or twisting motions.

• Difficulty with daily activities like reaching into a back pocket or throwing a ball.

• Gradual or Sudden Onset

• Symptoms may appear gradually due to wear and tear or overuse, or suddenly after injury or a specific event.

• Progressive Symptoms

• In the early stages, mild pain might occur at rest or during use.

• Over time, the condition can lead to severe pain, noticeable weakness, and difficulty performing basic activities.

These symptoms can significantly impact daily life, especially if left untreated. Addressing them early can prevent progression and improve shoulder function. 

What causes shoulder impingement?

Shoulder impingement is often linked to repetitive stress or structural changes in your shoulder. Here are some common causes:

• Overuse injuries trauma or sudden injury - impingement may result suddenly from an injury, such as a fall, car accident, or sports-related impact. These events can lead to inflammation or structural damage in your shoulder. They include:

• Repeated overhead movements, known as overhead rotation motions, are major contributors. Activities such as swimming, baseball, tennis, and volleyball often involve these movements, making athletes particularly susceptible.

• Jobs involving repetitive lifting or overhead tasks, like construction work, painting, or paper hanging, can place excessive stress on the shoulder joint and rotator cuff over time.

• Idiopathic causes – when shoulder impingement develops without a clear or obvious cause, known as idiopathic impingement.

• Age and wear-and-tear - older people are at risk due to natural degeneration of the rotator cuff and associated tendons. Bone spurs or changes in the acromion shape can also develop with aging, increasing the likelihood of impingement.

• Rotator cuff strain - mild injuries to your rotator cuff, even without an obvious traumatic event, can cause pain and inflammation over time, leading to impingement.

Shoulder impingement risk factors

Several factors can increase a person's likelihood of experiencing shoulder impingement. These include:

• Athletic activities - sports that involve repetitive overhead motions, such as swimming, baseball, volleyball, or tennis, put significant stress on your shoulder joint and rotator cuff, making athletes more prone to impingement.
• Physical occupations - jobs requiring repetitive use of the arms in overhead positions can lead to shoulder impingement over time. Examples include:
• Construction work
• Painting or decorating
• Window washing
• Hanging wallpaper or drywall.
• Repetitive strain - continuous overhead rotation motions, often seen in both sports and physical work, can lead to overuse injuries that gradually develop into shoulder impingement.
• Age - older individuals are at a higher risk due to wear-and-tear changes in the shoulder, such as rotator cuff degeneration or bone spurs forming on the acromion.
• Injury or trauma - sudden injuries, like a fall or impact, can trigger impingement symptoms by causing swelling or structural damage.

Understanding these contributing factors can help in preventing shoulder impingement through better practices, like modifying activities or incorporating strengthening exercises. 

Shoulder impingement treatment 

Effective treatment for shoulder impingement focuses on reducing pain and improving mobility through pain relief, physiotherapy and surgery therapies and lifestyle adjustments. 

Pain relief medication

Over-the-counter NSAIDs can help ease pain and reduce swelling. You should consult your healthcare provider if you plan to use them for more than 10 consecutive days.

Corticosteroids

These prescription medications reduce inflammation. Your provider might recommend cortisone injections directly into your shoulder for targeted relief.

Physical therapy 

Physical therapy for shoulder impingement focuses on restoring movement, reducing pain, and building strength. It includes stretching exercises to improve your range of motion, strengthening your rotator cuff, posture correction, and activity modifications to prevent strain. Therapists may also use hands-on techniques like massage and educate patients on care at home to maintain progress.

Shoulder impingement surgery 

Surgery may be recommended for shoulder impingement if nonsurgical treatments fail to provide relief. Common procedures include:

• Arthroscopic shoulder decompression - a minimally invasive surgery that removes inflamed tissue and bone spurs from the acromion to create more space for the rotator cuff. Learn more about shoulder arthroscopy 

• Bursectomy – removes an inflamed bursa to reduce swelling and improve shoulder movement.
• Acromioplasty (subacromial decompression) – removes bone spurs or the front edge of the acromion to prevent pinching of the rotator cuff tendons.
• Rotator cuff surgery - if the rotator cuff is torn or severely damaged, procedures like tendon repair, tendon transfer, or even shoulder replacement may be performed. Find out more about rotator cuff surgery

These surgeries are often performed using keyhole surgery, using small incisions and specialised instruments, including an arthroscope, for quicker recovery. 

Shoulder impingement exercises

Exercises for shoulder impingement often focus on improving your mobility, strengthening your rotator cuff, and enhancing posture. Here are some exercises that may be recommended for shoulder impingement to strengthen and improve shoulder function. If you repeat these exercises daily, you should expect to feel an improvement in shoulder pain within about two weeks:

1. Isometric shoulder internal and external rotation

   • Place a rolled-up towel under your arm of the affected shoulder for support.

   • Internal rotation - stand by a wall with your elbow bent at 90 degrees. Push your flat hand into the wall at 25-50% pressure and hold for 10 seconds. Repeat 10 times.

   • External rotation - turn so your outer hand pushes against the wall at 25-50% pressure. Hold for 10 seconds and repeat 10 times. Gradually increase pressure as tolerated.

2. Side-lying shoulder external rotation

   • Lie on your uninjured side with a towel under your affected arm.

   • With your arm bent at 90 degrees, lift a light weight (like a 1-pound water bottle) upward until it aligns with your shoulder, then slowly lower it.

   • Perform 3 sets of 10 reps, gradually increasing weight up to 5 pounds if tolerated.

3. Shoulder scaption exercise

   • Stand holding a light weight in your hand on the affected side.

   • Lift your arm at a 45-degree angle away from your body until fully extended, then lower it slowly.

   • Perform 3 sets of 10 reps, increasing weight as strength improves.

Diagnosis and tests for shoulder impingement

Each type of impingement has its own set of causes and treatments, and healthcare providers usually diagnose the specific issue based on symptoms, physical examination, and imaging studies.

• Physical examination - your healthcare provider will assess your shoulder's range of motion and check for pain or tenderness. They may ask about activities, sports, or work that involve repetitive shoulder movements to understand the cause of your symptoms.
• Imaging tests

  • X-rays - help identify bone abnormalities, such as spurs, that may contribute to impingement.

  • MRI (Magnetic Resonance Imaging) - provides detailed images of soft tissues, including tendons and muscles, to detect inflammation or tears.

  • Ultrasound - offers a real-time view of the shoulder's soft tissues, helping to identify swelling or structural issues.

These tests not only diagnose shoulder impingement but also rule out other conditions like rotator cuff tears, biceps tendon injuries, or arthritis.

Shoulder impingement recovery time

Recovery from shoulder impingement varies, but most patients notice improvement within a few weeks of starting treatment. However, full recovery can take several months, especially if physiotherapy or exercises are part of the plan. It's important to avoid intense physical activity or sports until your healthcare provider confirms it's safe, even if your symptoms seem to improve.

How to prevent shoulder impingement

To reduce the risk of shoulder impingement:

• Avoid overusing your shoulders and stop any activity if you feel pain - never push through discomfort.
• Always warm up and cool down before engaging in physical activities.
  Use proper equipment and techniques for sports or physical work.
• Maintain a healthy lifestyle with a balanced diet and exercise plan to support joint health.
• Seek medical advice promptly if you experience shoulder pain or other symptoms. Early intervention can prevent further issues.