Shoulder Clicking: Causes, When to Worry, and Self-Care

Why do I hear a clicking sound when I move my shoulder?

Hearing a clicking sound in your shoulder when you move it is a common phenomenon, often attributed to the normal movement of tendons and ligaments over bone, the release of gas bubbles within the joint, or, less frequently, an underlying musculoskeletal issue requiring professional attention.

Introduction to Shoulder Crepitus

The shoulder joint is one of the most complex and mobile joints in the human body, capable of a vast range of motion. With such intricate mechanics involving bones, cartilage, tendons, ligaments, and bursae, it's not uncommon to experience various sounds, including clicking, popping, grinding, or cracking. These sounds, collectively known as crepitus, can occur in many joints, and the shoulder is a frequent site due to its unique structure and extensive movement. While often benign, understanding the potential causes can help differentiate between a normal physiological occurrence and a sign of a more significant underlying problem.

Understanding Joint Sounds (Crepitus)

Crepitus refers to any grinding, creaking, cracking, grating, or popping sound that occurs when a joint moves. In the shoulder, these sounds can originate from several structures:

• Synovial Fluid: The fluid within the joint that lubricates and nourishes the cartilage.
• Tendons and Ligaments: Strong connective tissues that attach muscle to bone (tendons) and bone to bone (ligaments).
• Cartilage: The smooth tissue covering the ends of bones, allowing them to glide past each other without friction.
• Bursae: Small, fluid-filled sacs that reduce friction between bones, tendons, and muscles.

Common Causes of Shoulder Clicking

The source of shoulder clicking can range from completely harmless to indicative of a condition that requires intervention.

• Gas Bubbles (Cavitation):

  • Explanation: This is the most common and benign cause. Synovial fluid, which lubricates your joints, contains dissolved gases like oxygen, nitrogen, and carbon dioxide. When the joint capsule stretches during movement, the pressure within the joint changes, causing these gases to rapidly form and then collapse into bubbles. This process, known as cavitation, produces a popping or clicking sound. It's similar to cracking your knuckles and is generally painless and harmless.
  • Characteristics: Often occurs with specific movements after a period of stillness, and the sound typically cannot be immediately replicated.

• Tendons and Ligaments Snapping Over Bone:

  • Explanation: As muscles contract and joints move, tendons and ligaments can sometimes slide or "snap" over bony prominences. This is especially common in areas where these structures cross a joint or are under tension.
  • Common Sites:
    • Biceps Tendon: The long head of the biceps tendon can snap in and out of its groove in the humerus (upper arm bone).
    • Rotator Cuff Tendons: While less common for a distinct "snap," an inflamed or thickened rotator cuff tendon might rub against the acromion (part of the shoulder blade).
    • Scapula (Shoulder Blade): The scapula can sometimes rub or snap against the ribs during arm movements, particularly in cases of scapulothoracic dyskinesis (abnormal shoulder blade movement).
  • Characteristics: May be repetitive with certain movements, potentially accompanied by a sensation of something moving.

• Bursitis:

  • Explanation: Inflammation of a bursa (a fluid-filled sac that reduces friction). In the shoulder, subacromial bursitis is common. An inflamed bursa can thicken, leading to increased friction and a clicking or grinding sensation as tendons move over it.
  • Characteristics: Often accompanied by pain, especially with overhead movements, and tenderness to touch.

• Osteoarthritis (Degenerative Joint Disease):

  • Explanation: The protective cartilage that cushions the ends of bones gradually wears away. As cartilage thins or disappears, bone-on-bone friction can occur, leading to a grinding, creaking, or clicking sound. Bone spurs (osteophytes) can also develop, further contributing to friction.
  • Characteristics: Typically accompanied by pain, stiffness (especially after rest), reduced range of motion, and a persistent grinding sensation. More common in older adults.

• Labral Tears:

  • Explanation: The labrum is a ring of cartilage that deepens the shoulder socket (glenoid) and helps stabilize the joint. A tear in the labrum (e.g., SLAP tear, Bankart lesion) can cause clicking, popping, or catching sensations as the joint moves and the torn piece of cartilage gets pinched.
  • Characteristics: Often associated with a specific injury (e.g., fall, dislocation, repetitive overhead activity). May involve pain, instability, and a sensation of the shoulder "catching" or "giving way."

• Shoulder Instability or Hypermobility:

  • Explanation: If the shoulder joint is overly loose (hypermobile) or has a tendency to partially dislocate (subluxation), the bones may move excessively within the joint capsule. This abnormal movement can lead to clicking or clunking sounds as the joint shifts.
  • Characteristics: May be accompanied by a feeling of apprehension, a sense that the shoulder might slip out, or actual episodes of subluxation.

• Scapulothoracic Dysfunction:

  • Explanation: The scapula (shoulder blade) glides over the rib cage. If the muscles that control scapular movement are weak, imbalanced, or uncoordinated, the scapula may move abnormally, leading to friction or snapping sounds (sometimes called "snapping scapula syndrome").
  • Characteristics: Sounds often heard when moving the arm, especially overhead or reaching across the body. May be associated with poor posture or muscle imbalances.

• Post-Surgical Changes:

  • Explanation: Following shoulder surgery, scar tissue formation, altered mechanics, or implant presence can sometimes lead to new or persistent clicking sounds.

When to Be Concerned

While many clicking sounds are benign, certain accompanying symptoms warrant a medical evaluation. You should consult a healthcare professional if the clicking is:

• Painful: Especially if the pain is sharp, persistent, or worsens with movement.
• Accompanied by Swelling or Redness: Signs of inflammation.
• Associated with Weakness: Difficulty lifting or moving the arm.
• Linked to Instability: A feeling that the shoulder might "give out" or dislocate.
• Followed by a Specific Injury: Such as a fall or direct blow.
• Persistent and Worsening: If the sound or associated symptoms don't improve or get worse over time.
• Accompanied by a Catching or Locking Sensation: Indicating something might be physically impeding movement.

What You Can Do (Self-Care & Prevention)

For benign, painless clicking, general shoulder health strategies can be beneficial:

• Maintain Good Posture: Proper posture helps align the shoulder joint and can reduce undue stress on surrounding structures.
• Regular Mobility and Flexibility: Gentle range-of-motion exercises can help maintain joint health and prevent stiffness.
• Strengthen Supporting Muscles: Focus on strengthening the rotator cuff muscles, scapular stabilizers, and core muscles to improve shoulder stability and control.
  • Examples: External rotations, internal rotations, band pull-aparts, rows, and overhead presses (if pain-free).
• Avoid Overuse or Repetitive Stress: Be mindful of activities that consistently provoke the clicking, and consider modifying them or taking breaks.
• Warm-Up Adequately: Before any physical activity, ensure your shoulder muscles are properly warmed up to improve elasticity and reduce the risk of injury.
• Listen to Your Body: If a movement causes pain or discomfort, stop and modify.

When to See a Professional

If your shoulder clicking is accompanied by pain, weakness, instability, or a restricted range of motion, it's crucial to seek professional medical advice. A physician, physical therapist, or sports medicine specialist can conduct a thorough examination, which may include special tests, imaging (such as X-rays, MRI, or ultrasound), and a detailed history to accurately diagnose the cause of the clicking and recommend an appropriate treatment plan. This might involve physical therapy, medication, injections, or in some cases, surgical intervention.

Conclusion

Shoulder clicking is a common occurrence, and in many instances, it's a normal physiological sound. However, understanding the potential underlying causes is essential. While harmless gas bubbles are a frequent culprit, persistent or painful clicking, especially when accompanied by other symptoms, should always prompt a professional evaluation. Prioritizing shoulder health through proper movement mechanics, strength, and flexibility can help maintain optimal joint function and reduce the likelihood of problematic sounds.