Shoulder Impingement or Rotator Cuff Tear? How to Tell the Difference

Shoulder pain is one of the most common musculoskeletal complaints among adults, especially for those who work with their hands, lift weights, or perform repetitive overhead tasks. Two conditions often mistaken for one another are shoulder impingement and a rotator cuff tear. While they share overlapping symptoms, understanding the differences can help you know when to rest, when to seek treatment, and what kind of recovery to expect.

This article breaks down the distinctions in symptoms, clinical tests, imaging, and treatment pathways, helping you make more informed decisions about your shoulder health.

What Is Shoulder Impingement?

Shoulder impingement happens when the tendons of the rotator cuff or the bursa (a fluid-filled sac) become compressed or irritated within the narrow space beneath the acromion. This friction causes inflammation, pain, and limited mobility.

Impingement is typically the result of:

• Repetitive overhead activities
• Poor posture
• Weakness or imbalance in the shoulder muscles
• Tightness in the chest or upper back
• Age-related tissue irritation

What Is a Rotator Cuff Tear?

A rotator cuff tear occurs when one or more of the rotator cuff tendons partially or fully detach from the bone. Tears can be degenerative, developing slowly over years, or acute, caused by trauma such as a fall or lifting something heavy.

Common causes include:

• Repetitive strain
• Age-related tendon weakening
• Sudden force or trauma
• Overuse from sports or manual work

Symptom Differences: What Each Condition Feels Like

Although both conditions cause shoulder pain, their symptoms have distinct patterns.

1. Pain Location and Nature

Shoulder Impingement:

• Pain on the front or outer shoulder
• Sharp pain when lifting the arm overhead
• Aching pain at rest
• Pain often worse at night, especially when lying on the affected side

Rotator Cuff Tear:

• Deep, dull shoulder pain
• Weakness is more pronounced than pain
• Difficulty lifting or rotating the arm
• Sudden tearing sensation if caused by trauma

2. Weakness

Impingement:

Weakness usually comes from pain—not actual damage. Once the pain eases, strength often returns.

Tear:

Weakness is noticeable and persistent. Even with pain relief, the arm may struggle with simple movements such as lifting a cup or combing hair.

3. Activity Triggers

Impingement:

Overhead movements, reaching behind the back, or lifting aggravate symptoms.

Tear:

Pain and weakness can occur during daily tasks, even those below shoulder level.

How Clinicians Test for These Conditions

Healthcare professionals rely on physical tests to narrow down the likely diagnosis.

Clinical Tests for Shoulder Impingement

Practitioners often use several pain-provocation tests:

• Neer test: Lifting the arm passively overhead while stabilising the shoulder
• Hawkins-Kennedy test: Flexing and internally rotating the arm
• Painful arc test: Pain occurring between 60° to 120° of arm elevation

Positive results typically point to irritation of the rotator cuff tendons or bursa.

Clinical Tests for a Rotator Cuff Tear

Tests focus on functional strength and tendon integrity:

• Empty Can (Jobe) test: Checks supraspinatus tendon strength
• External rotation strength test: Assesses infraspinatus and teres minor
• Drop arm test: Identifies potential full-thickness tears
• Lift-off test: Screens for subscapularis tendon weakness

When strength is significantly reduced—even with minimal pain— a tear becomes more likely.

Imaging: When You Need It and What It Shows

While many shoulder issues can be managed without imaging, certain cases require a deeper look.

Ultrasound

• Useful for identifying rotator cuff tears
• Helps detect inflammation in the bursa
• Non-invasive and affordable

MRI

• Best for visualising tendon damage
• Shows swelling, fluid, partial and full-thickness tears
• Commonly used for surgical planning

X-ray

• Cannot show soft tissues, but can help rule out fractures
• May show bone spurs that contribute to impingement

Imaging is usually recommended if symptoms persist beyond several weeks or if a significant traumatic event occurred.

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Treatment Pathways: How Management Differs

Because impingement and tears differ in severity and structure, treatment approaches vary.

Treatment for Shoulder Impingement

Most cases improve with conservative, non-surgical care.

1. Activity Modification

• Reducing overhead movements
• Avoiding repetitive loading
• Adjusting posture and workplace ergonomics

2. Physiotherapy

Focuses on:

• Strengthening the rotator cuff
• Improving scapular control
• Stretching tight chest and upper back muscles
• Correcting posture

3. Anti-inflammatory Strategies

• Ice therapy
• Oral anti-inflammatories (if recommended)
• Corticosteroid injections for persistent cases

4. Recovery Outlook

With proper rehab, many people recover within 6–12 weeks, although long-standing cases may take longer.

Treatment for a Rotator Cuff Tear

Management depends on whether the tear is partial or full-thickness.

1. Conservative Treatment (Partial Tears)

• Physiotherapy to rebuild strength
• Activity modification
• Anti-inflammatory medication
• Platelet-rich plasma (PRP) injections (in some clinical practices)

2. Surgical Treatment (Full-Thickness or Severe Tears)

Surgery may be recommended when:

• There is significant weakness
• A traumatic injury caused the tear
• Conservative care for 3–6 months doesn’t improve function
• The patient is young or highly active

Recovery from surgical repair can take several months and typically includes structured physiotherapy.

Key Differences Summarised (List Format)

How to Differentiate Shoulder Impingement from a Rotator Cuff Tear

• Impingement usually causes sharp pain with overhead movement; tears cause deeper, persistent pain.
• Impingement-related weakness is mostly due to pain; tears cause true strength loss.
• Impingement symptoms often improve with rest; tears persist regardless of rest.
• Impingement responds well to physiotherapy alone; tears may require surgical repair, especially if full-thickness.
• Clinical strength tests like the drop arm test point toward tears, while pain-provocation tests point to impingement.
• MRI or ultrasound can confirm a tear, while impingement often does not require advanced imaging unless symptoms persist.

FAQs

1. Can shoulder impingement turn into a rotator cuff tear?

Yes. Long-term untreated impingement can contribute to tendon degeneration, making the rotator cuff more vulnerable to tearing over time.

2. How do I know if my shoulder pain is serious?

Seek professional evaluation if you experience sudden weakness, severe pain after trauma, or persistent symptoms lasting longer than 6 weeks.

3. Do I always need an MRI?

No. Many diagnoses can be made clinically. MRI is generally reserved for suspected tears, traumatic injuries, or symptoms that do not improve with treatment.

4. Will a rotator cuff tear heal on its own?

Partial tears may improve with strengthening and rehabilitation. Full-thickness tears generally do not heal without surgical repair.

5. Can I continue exercising with shoulder impingement?

Yes—low-pain, modified movement is usually safe. Avoid painful overhead activities and focus on posture and controlled shoulder strengthening.

6. Is surgery always required for rotator cuff tears?

Not necessarily. Many partial tears respond well to physiotherapy. Surgery is typically reserved for large tears, young active individuals, or cases unresponsive to conservative care.

7. How long does recovery take?

Impingement recovery can take 6–12 weeks. After rotator cuff surgery, full recovery often requires 4–6 months of rehabilitation.