Shoulder Impingement Syndrome

Upper Limb

Overview

Shoulder impingement syndrome occurs when the rotator cuff tendons and subacromial bursa become compressed beneath the acromion process during overhead activities. This is one of the most common causes of shoulder pain, particularly in middle-aged individuals and overhead athletes. The condition results from a combination of structural narrowing and functional movement dysfunction.

Pathophysiology

Impingement occurs when the subacromial space is reduced, causing compression of the supraspinatus tendon, infraspinatus tendon, and subacromial bursa during arm elevation. This may result from anatomical factors (hooked acromion, osteophytes, thickened bursa), postural dysfunction (forward shoulder posture, thoracic kyphosis), scapular dyskinesis (abnormal scapular kinematics), or rotator cuff weakness. Repetitive compression leads to inflammation, microtrauma, and potential tendon degeneration. Secondary impingement involves dynamic compression from muscular imbalance and instability rather than structural narrowing.

Patient Education

Most impingement syndrome can be effectively managed with activity modification, postural correction, and strengthening exercises; avoiding forceful overhead activities during the acute phase allows inflammation to settle and prevents progression to rotator cuff tears.

Typical Presentation

Site

Anterolateral shoulder, particularly over the greater tuberosity and subacromial region; pain may radiate to lateral arm

Quality

Dull, aching pain; may be sharp with specific movements; sensation of catching or grinding

Intensity

Mild to moderate (3-7/10); often worsens with overhead activities and may disturb sleep when lying on affected side

Aggravating

Overhead reaching and lifting, throwing activities, cross-body adduction, repetitive activities, lying on affected shoulder, pushing movements (e.g., push-ups), carrying heavy objects

Relieving

Rest, immobilization or sling support, ice application, anti-inflammatory medication, gentle pendulum exercises, postural correction, specific rotator cuff strengthening

Associated

Scapular dyskinesis (winging or prominence of medial border), weakness in external rotation and abduction, restricted internal rotation, postural dysfunction (forward head, rounded shoulders), possible referred pain to neck or upper back, clicking or catching sensation with movement

Orthopaedic Tests

Neer Impingement Sign

Procedure

Patient supine or seated. Examiner stabilises the scapula with one hand and passively elevates the arm in full internal rotation through forward flexion to end-range.

Positive Finding

Reproduction of anterior shoulder pain at end-range forward flexion

Sensitivity / Specificity

72% / 60%

Hegedus et al., 2015, British Journal of Sports Medicine

Interpretation

Positive finding suggests subacromial impingement but lacks specificity. Often used as screening test; positive result may warrant further imaging or injection confirmation.

Hawkins-Kennedy Impingement Sign

Procedure

Patient seated or standing. Examiner flexes shoulder to 90° and internally rotates the arm with elbow flexed at 90°, applying gentle overpressure into internal rotation.

Positive Finding

Reproduction of anterior or lateral shoulder pain

Sensitivity / Specificity

72% / 44%

Hegedus et al., 2015, British Journal of Sports Medicine

Interpretation

Reproduces mechanical compression of subacromial structures. Positive result suggests subacromial impingement but has low specificity; best used in combination with other tests.

Empty Can Test (Jobe's Test)

Procedure

Patient standing with arms at 90° abduction in the scapular plane, elbows extended, thumbs pointing downward (empty can position). Examiner applies downward resistance.

Positive Finding

Pain (especially anterior shoulder) or weakness in infraspinatus and supraspinatus strength testing

Sensitivity / Specificity

65% / 75%

Itoi et al., 1999, Journal of Shoulder and Elbow Surgery

Interpretation

Primarily assesses rotator cuff weakness and pain, particularly supraspinatus involvement. Pain or weakness may indicate supraspinatus pathology secondary to impingement.

Infraspinatus Strength Test (Hornblower's Test)

Procedure

Patient's arm is positioned at 90° abduction with elbow flexed 90°. Examiner applies internal rotation resistance while stabilising the elbow.

Positive Finding

Pain or weakness in external rotation against resistance

Sensitivity / Specificity

50% / 80%

Interpretation

Tests infraspinatus function; positive finding suggests rotator cuff involvement. Pain may indicate secondary rotator cuff pathology from chronic impingement.

Scapular Dyskinesis Assessment

Procedure

Patient performs 5–10 cycles of bilateral shoulder elevation in standing (arms at sides, raising to shoulder height). Examiner observes scapular position and movement bilaterally from behind.

Positive Finding

Asymmetrical scapular winging, premature elevation, or altered scapulohumeral rhythm

Sensitivity / Specificity

68–76% / 54–59%

Hegedus et al., 2015, British Journal of Sports Medicine

Interpretation

Abnormal scapular mechanics may contribute to reduced subacromial space and impingement; positive finding suggests need for scapular stabilisation training.

Painful Arc Sign

Procedure

Patient standing with arm at side. Examiner passively or patient actively abducts shoulder through full range of motion. Examiner notes any pain during arc.

Positive Finding

Pain occurring specifically between 60–120° of abduction (the 'painful arc')

Sensitivity / Specificity

53% / 67%

Hegedus et al., 2015, British Journal of Sports Medicine

Interpretation

Pain in mid-range abduction suggests subacromial structure irritation; absence of pain at terminal range helps differentiate from other pathology. Low sensitivity limits value as standalone test.

⚠ Red Flags

  • •Acute trauma or fall on shoulder with severe pain and loss of function
  • •Signs of complete rotator cuff tear (inability to initiate or maintain abduction, positive drop arm test)
  • •Severe progressive neurological symptoms suggesting nerve compression
  • •Systemic symptoms (fever, malaise, unexplained weight loss) suggesting infection or malignancy
  • •History of cancer with shoulder pain
  • •Chest pain or cardiopulmonary symptoms coinciding with shoulder pain
  • •Radiating pain with dermatomal distribution suggesting cervical radiculopathy

⚡ Yellow Flags

  • •Symptom duration exceeding 3 months despite conservative management
  • •Catastrophizing beliefs about shoulder pain or fear-avoidance behavior
  • •High levels of psychological distress or depression
  • •Work or sport demands incompatible with current function
  • •Poor compliance with rehabilitation exercises
  • •Expectation of quick resolution without participation in therapy
  • •Multiple failed treatments suggesting possible chronicity

Osteopathic Techniques

Region

Thoracic spine and ribcage

Technique

HVLA

Rationale

Thoracic hypokyphosis and restricted costovertebral mobility contribute to anterior shoulder posture and scapular dyskinesis; thoracic mobilization improves postural mechanics and scapular positioning during arm elevation

Region

Scapulothoracic articulation and serratus anterior

Technique

Soft Tissue

Rationale

Direct soft tissue release of serratus anterior, upper trapezius, and pectoralis minor addresses muscular imbalances causing scapular dyskinesis and improving scapular upwardly rotation during overhead movement

Region

Glenohumeral joint and rotator cuff

Technique

Functional

Rationale

Functional technique facilitates optimal rotator cuff recruitment patterns and neuromuscular re-education, promoting dynamic stability and reducing compensatory stress on impinged structures

Region

Pectoralis minor and anterior shoulder capsule

Technique

MET

Rationale

Muscle energy technique releases tight pectoralis minor and anterior capsule restrictions that pull the scapula into dyskinetic positioning and narrow the subacromial space

Region

Cervical spine and cervicothoracic junction

Technique

Articulation

Rationale

Gentle articulation improves cervical and upper thoracic mobility, reducing postural compensation patterns that perpetuate forward shoulder posture and impingement

Region

Subacromial bursa and glenohumeral structures

Technique

Lymphatic

Rationale

Lymphatic drainage techniques reduce inflammatory fluid accumulation in the subacromial space, decreasing local irritation and creating more space for rotator cuff movement

Add-On Approaches

Chinese Medicine

Acupuncture targeting LI15 (Jianyu), LI11 (Quchi), and local ashi points combined with moxibustion may reduce inflammation and pain; herbal formulas such as Xue Fu Zhu Yu Tang address qi and blood stagnation associated with chronic impingement

Chiropractic

Glenohumeral joint manipulation (grade III-IV mobilizations) combined with scapular mobilization and postural correction may improve joint mechanics; cervical and thoracic manipulation addresses underlying biomechanical dysfunction

Physiotherapy

Scapular stabilization exercises, progressive rotator cuff strengthening (especially external rotation in 90/90 position), proprioceptive training, and activity-specific rehabilitation optimize scapular kinematics and dynamic stability

Remedial Massage

Deep tissue massage to upper trapezius, levator scapulae, and infraspinatus releases muscular tension; trigger point therapy addresses myofascial restrictions contributing to postural dysfunction and pain referral patterns

Rehabilitation Exercises

Pendulum Exercises

Range of MotionBeginner

Cross-Body Shoulder Stretch

StretchingBeginner

Doorway Pectoralis Stretch

StretchingBeginner

Sleeper Stretch for Internal Rotation

Range of MotionBeginner

Resisted External Rotation at 0 Degrees Abduction

StrengtheningBeginner

Prone Y-T-W Raises

StrengtheningIntermediate

Side-Lying External Rotation

StrengtheningBeginner

Quadruped Shoulder Taps (Scapular Stabilization)

StrengtheningIntermediate

Prone Horizontal Abduction (T-Position)

StrengtheningIntermediate

Prone Cobra with Scapular Retraction

PosturalIntermediate

Resistance Band External Rotation in 90/90 Position

StrengtheningIntermediate

Standing Single-Arm Overhead Stability (with Light Weight)

BalanceAdvanced

Referral Criteria

  • •Persistent impingement symptoms unresponsive to conservative treatment after 8-12 weeks
  • •Clinical signs suggesting full-thickness rotator cuff tear (positive drop arm test, severe weakness disproportionate to pain)
  • •Suspicion of labral pathology with instability symptoms
  • •Neurological deficits or cervical radiculopathy not responding to conservative care
  • •Imaging findings indicating surgical candidates (severe osteophyte burden, significant subacromial narrowing)
  • •Systemic disease presentation requiring investigation (rheumatoid arthritis, inflammatory conditions)
  • •Acute traumatic injury requiring orthopedic assessment
  • •Patient preference for surgical consultation after trial of conservative management