What are the symptoms of Shoulder Impingement Syndrome?

Common symptoms include: Pain at the front and side of the shoulder; Pain that worsens with overhead reaching or lifting; Pain when lying on the affected shoulder at night; Weakness with arm elevation or rotation; Painful arc of motion, typically between 60 and 120 degrees of elevation.

How is Shoulder Impingement Syndrome diagnosed?

Diagnosis typically involves: Medical history focusing on activities, symptom patterns, and aggravating factors; Physical examination including impingement tests (Neer, Hawkins-Kennedy); Assessment of rotator cuff strength and scapular mechanics; X-rays may show acromial shape, spurs, or calcifications.

What are the treatment options for Shoulder Impingement Syndrome?

Treatment options range from conservative measures to surgical interventions, including: Activity modification to avoid pain-provoking overhead movements; Physical therapy focusing on rotator cuff strengthening and scapular stabilization; Postural correction and ergonomic modifications; NSAIDs for pain and inflammation; Ice application after activity.

Shoulder Impingement Syndrome

Also known as: Subacromial impingement syndrome, Subacromial impingement, Rotator cuff impingement, Shoulder impingement, Impingement syndrome of the shoulder, SIS (shoulder impingement syndrome)

Last updated: December 18, 2024

Shoulder impingement syndrome is a condition in which the rotator cuff tendons and the subacromial bursa are compressed or irritated in the narrow space beneath the acromion. This can lead to pain, inflammation, and reduced shoulder function, often worsening with overhead reaching or lifting. Pain may be felt at the front and side of the shoulder and can be worse at night when lying on the affected side.

Key Facts

•Shoulder impingement syndrome occurs when the rotator cuff tendons and subacromial bursa become compressed or irritated as they pass through the narrow space beneath the acromion
•Pain at the front and side of the shoulder
•Diagnosed through history, physical exam, and imaging
•First-line treatment includes exercise, weight management, and activity modification

What It Is

Shoulder impingement syndrome occurs when the rotator cuff tendons and subacromial bursa become compressed or irritated as they pass through the narrow space beneath the acromion. This compression may cause pain, inflammation, and reduced function, particularly with overhead activities. It is one of the most common causes of shoulder pain.

Affected Anatomy

This condition affects several structures in and around the joint:

•Subacromial space (area between acromion and humeral head)
•Subacromial bursa
•Rotator cuff tendons, especially supraspinatus
•Acromion and acromioclavicular joint
•Coracoacromial ligament
•Biceps tendon (may be secondarily affected)

Common Symptoms

Symptoms can vary in intensity and may change over time. Common experiences include:

•Pain at the front and side of the shoulder
•Pain that worsens with overhead reaching or lifting
•Pain when lying on the affected shoulder at night
•Weakness with arm elevation or rotation
•Painful arc of motion, typically between 60 and 120 degrees of elevation
•Difficulty reaching behind the back
•Gradual onset of symptoms in most cases
•Stiffness may develop if motion becomes limited

Causes and Risk Factors

Multiple factors can contribute to the development of this condition:

Causes

•Repetitive overhead activities causing cumulative microtrauma
•Anatomical factors such as hooked or curved acromion shape
•Thickening of the subacromial bursa or rotator cuff tendons
•Bone spurs or osteophytes on the acromion or acromioclavicular joint
•Muscle imbalances affecting scapular mechanics
•Poor posture or rounded shoulders
•Weakness of rotator cuff muscles leading to superior migration of humeral head

Risk Factors

•Occupations requiring repetitive overhead work (painting, carpentry)
•Participation in overhead sports (swimming, baseball, tennis)
•Age over 40, as degenerative changes accumulate
•Poor posture with forward head and rounded shoulders
•Muscle weakness or imbalances around the shoulder
•Previous shoulder injury or surgery
•Anatomical variations that narrow the subacromial space

How It's Diagnosed

Diagnosis typically involves a combination of clinical assessment and imaging studies:

•Medical history focusing on activities, symptom patterns, and aggravating factors
•Physical examination including impingement tests (Neer, Hawkins-Kennedy)
•Assessment of rotator cuff strength and scapular mechanics
•X-rays may show acromial shape, spurs, or calcifications
•MRI may be used to evaluate rotator cuff and bursal pathology
•Ultrasound can assess rotator cuff and bursa dynamically
•Diagnostic subacromial injection may help confirm diagnosis if pain is relieved

Treatment Options

Treatment approaches range from conservative measures to surgical interventions, often starting with the least invasive options:

Self-Care and Activity Modification

•Activity modification to avoid pain-provoking overhead movements
•Postural correction and ergonomic modifications
•Ice application after activity
•Treatment of underlying rotator cuff pathology if present

Physical Therapy and Exercise

•Physical therapy focusing on rotator cuff strengthening and scapular stabilization
•Stretching exercises for tight anterior structures

Medications

•NSAIDs for pain and inflammation

Injections and Office-Based Procedures

•Subacromial corticosteroid injections may provide temporary relief

Surgery

•Arthroscopic subacromial decompression may be considered for refractory cases

Prognosis and Recovery

The course of this condition varies between individuals:

•Many cases improve with conservative treatment over weeks to months
•Consistent adherence to rehabilitation is important for lasting improvement
•Some individuals may progress to rotator cuff tears if impingement is not addressed
•Surgical outcomes are generally favorable when conservative treatment fails
•Chronic or recurrent symptoms may occur in some individuals