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Atlas · Shoulder

Infraspinatus

Infraspinatus is part of the rotator cuff on the back of the shoulder blade. It helps turn the arm outward and stabilize the shoulder during lifting. Muscle tenderness can accompany shoulder pain, but weakness, night pain and difficulty reaching also occur with tendon disease, tears, joint stiffness or neck-related conditions.

Infraspinatus
Body region
Shoulder
Trigger points
3
documented in this muscle
Common symptoms
4
patterns cataloged
Contributors
4
Factors to assess

Muscle overview

Symptoms and first steps

Practical first steps

  • Temporarily reduce the most painful lifting height or load while keeping comfortable shoulder motion.
  • Try a pillow under the forearm when resting or sleeping and bring frequently used items closer.
  • Build outward-rotation strength gently. Avoid forceful sleeper stretches and deep pressure beyond the shoulder-blade borders.

When to seek assessment

  • Seek prompt assessment for sudden weakness after injury, inability to raise the arm, suspected dislocation or a hot swollen shoulder with fever.
  • Persistent weakness, visible muscle wasting, arm numbness or a worsening loss of passive movement deserves examination.
  • Chest pain, breathlessness or shoulder pain with acute systemic symptoms requires urgent medical assessment.

Resisted external rotation and an external-rotation lag test assess the posterior cuff. A positive lag can raise concern for a tear; a negative lag cannot exclude one. Neither test diagnoses an infraspinatus trigger point.

Examination, palpation and treatment evidence

Illustrated overview

Infraspinatus

Blue highlights the muscle. Crosses mark representative trigger-point sites; shaded areas show possible referred pain. These examples do not correspond one-to-one with the numbered points below. Patterns vary and cannot diagnose the cause of pain.

Illustrated overview

Infraspinatus · Anatomy 1

Anatomical view of the illustrated muscle.

Open full-size image

Trigger points

1. TrP1

Location. Back of shoulder blade

Trigger point map
Infraspinatus — Infraspinatus · Trigger-point examples 1Open full-size image

Regional muscle reference; this is not an individual map of the selected numbered trigger point.

Referred pain map
Infraspinatus — Referred pain mapOpen full-size image

Regional muscle reference; this is not an individual map of the selected numbered trigger point.

Pain referral. Front of shoulder, down arm

Pain Pattern

  • Front of shoulder
  • Down front of arm
  • Biceps area
  • Wrist
  • Upper back

What This Pain Feels Like

Symptoms may be noticed with lifting or rotating the arm; the location does not distinguish muscle from cuff tendon pain. Record a specific task such as putting on a jacket or reaching a shelf instead of assuming a short muscle.

What Patients Report

  • Pain when reaching up
  • Difficulty putting on coat
  • Pain in front of shoulder
  • Weakness when lifting

What Makes It Worse

  • Reaching overhead
  • External rotation
  • Throwing
  • Sleeping on affected side
  • Reaching behind back
Browse related exercises (13)

Symptoms patients report

Posterior or outer shoulder ache Symptoms may be noticed with lifting or rotating the arm; the location does not distinguish muscle from cuff tendon pain.

Difficulty reaching or dressing Record a specific task such as putting on a jacket or reaching a shelf instead of assuming a short muscle.

Pain with outward rotation This loads the posterior cuff; the examination should distinguish pain-limited effort from substantial weakness.

Sleep disturbance Side-lying may be uncomfortable, but night pain is not a specific trigger-point sign.

Contributors to assess

More overhead or rotational activity Throwing, swimming and unfamiliar lifting may exceed current shoulder capacity.

Long periods with the arm unsupported Adjusting reach distance or supporting the forearm may improve comfort without requiring one fixed posture.

Previous injury or reduced strength Recent trauma or persistent loss of force changes the assessment and progression plan.

Interrupted sleep or limited recovery These can influence pain and tolerance; they do not prove tissue damage or a trigger point.

For clinicians and supervised training

Clinical reference

Use the map to orient the examination; record the actual familiar pain distribution alongside movement, loading and neurological findings.

Anatomy and palpation

Anatomical relationships

Infraspinatus occupies the posterior scapula below its spine and attaches through its tendon to the middle facet of the greater tubercle of the humerus. It works with other cuff muscles to externally rotate the arm and stabilize the humeral head.[6]

  • The scapular spine is the horizontal ridge dividing the back of the shoulder blade.
  • The infraspinous fossa is the broad bony surface below that ridge, between the medial and lateral scapular borders.
  • The tendon travels laterally beneath the posterior deltoid toward the humerus.

Nearby structures. Teres minor lies along the lower lateral region. The suprascapular nerve passes around the spinoglenoid notch; the thorax lies beyond the scapular boundaries. The belly is on the scapula, not between the scapula and spine.

Palpation

Patient position. Seated with the forearm supported, or side-lying with the symptomatic shoulder uppermost and relaxed.

Find the landmarks

  • Identify the scapular spine and both scapular borders.
  • Stay over the broad infraspinous fossa below the spine; distinguish this from the interscapular muscles medial to the blade.

Examination sequence

  1. Use light flat fingertips across the posterior muscle belly. A gentle outward-rotation effort can help orient the contraction before relaxing for palpation.
  2. Ask whether a sensitive region reproduces the familiar shoulder complaint and compare with tendon loading and neck movement.

Document the findings

  • A sensitive band with familiar referral may support a myofascial contribution.
  • Palpable tenderness can coexist with cuff disease; temporary relief does not exclude a tear.

Limits and precautions

  • Avoid hard pressure on the scapular ridge, lateral notch or areas beyond the scapular borders.
  • Stop for arm tingling or electrical pain.
  • Needling near the scapula requires trained anatomical technique because of adjacent neurovascular structures and thorax; no self-needling instructions apply.
[6][2]

Examination and tests

3

Resisted external rotation[8][3]

Assess posterior cuff loading and compare pain with loss of force.

Position
Seated with the elbow bent to 90 degrees at the side; a small towel can support the elbow.
Technique
The clinician stabilizes the upper arm and gradually resists outward rotation of the forearm, comparing both sides and recording pain and force separately.
Positive finding
Familiar shoulder pain, reduced force or inability to hold against comparable resistance.
Interpretation
Supports a cuff-related assessment; marked weakness requires consideration of a tear or suprascapular neuropathy.
Limitations
Pain inhibits force, teres minor also contributes, and a positive result does not isolate infraspinatus or diagnose a trigger point.

External rotation lag sign at the side[7][8]

Assess loss of the ability to maintain passive external rotation when a posterior cuff tear is suspected.

Position
Seated, elbow flexed to 90 degrees and shoulder slightly elevated in the scapular plane, supported by the clinician.
Technique
The clinician gently places the shoulder near its available passive external-rotation limit, backs off slightly, then asks the patient to maintain the position while releasing wrist support and continuing to support the elbow.
Positive finding
The forearm drifts inward because the patient cannot maintain the externally rotated position.
Interpretation
A clear lag increases concern for a cuff tear and can justify further assessment in the right clinical setting.
Limitations
High specificity but low sensitivity in the ROW cohort: a negative test does not exclude a tear. Pain, restricted passive motion and neurological weakness can affect performance. It is not a trigger-point test.

Active versus passive shoulder motion with neck screen[3][4][5]

Distinguish a load-related shoulder problem from joint stiffness or cervical referral.

Position
Seated for active elevation and gentle neck movements; supported supine or seated for passive shoulder motion.
Technique
Compare active elevation and rotation with clinician-assisted passive range. Record the task and pain location; then check whether neck movement or a neurological examination reproduces the arm complaint.
Positive finding
Marked passive restriction, active motion far below available passive motion, or concordant cervical/neurological findings.
Interpretation
Passive restriction suggests a stiff joint presentation; disproportionate active loss prompts cuff/nerve assessment; neck findings may redirect care.
Limitations
These are pattern-finding examinations, not tissue-specific proof. Guarding and pain influence both active and passive motion.

Distinguishing other causes

Rotator cuff tendinopathy or tear[3][7]

Findings that matter. Pain on lifting and external rotation; traumatic onset, substantial weakness or a clear lag increases concern for a tear.

Next step. Assess force and active/passive motion. Acute traumatic weakness needs prompt assessment; imaging is selected when it changes care.

Adhesive capsulitis or glenohumeral arthritis[5][3]

Findings that matter. Both active and passive motion are limited, often including external rotation, with dressing and reaching difficulty.

Next step. Assess the joint rather than forcing posterior shoulder stretching or treating only the muscle belly.

Suprascapular neuropathy[6]

Findings that matter. Persistent outward-rotation weakness or visible hollowing of the infraspinous fossa, especially if weakness exceeds pain limitation.

Next step. Arrange a neurological and shoulder assessment; electrodiagnostic testing or imaging may be appropriate.

Cervical radiculopathy[4]

Findings that matter. Arm pain with numbness, reflex/strength changes or a clear relationship to neck movement.

Next step. Perform a cervical and neurological examination before attributing distal symptoms to shoulder referral.

Treatment selection and progression

Clinician-delivered care

Dry needling for a painful infraspinatus myofascial presentation[1]

Consider when. Assessed shoulder pain with concordant infraspinatus tenderness when temporary relief could help reaching or exercise.

A qualified clinician identifies the infraspinous fossa below the scapular spine and assesses cuff and cervical findings before selecting a muscular target; discuss bleeding, infection and thoracic injury risks.

Dose and review
The muscle-specific trial tested one session; no universal needle depth or treatment series follows from it.
Progression
Recheck a shelf reach, dressing or outward-rotation task within a week and continue only if useful activity improves.
Stop or reassess
New chest pain or breathlessness after shoulder-region needling requires urgent assessment; report new weakness or a sustained flare.
Evidence and limits
In 66 adults aged 65 or older, adding latent-point DN to active-point DN improved pain immediately and at one week, without a grip-strength advantage. Both groups received DN; lasting functional benefit and superiority over sham or rehabilitation were not established.

Self-care and activity

Adjust painful reach and lifting demands[3]

Consider when. Atraumatic shoulder pain with manageable activity-related symptoms.

Temporarily lower the shelf height, shorten a throwing or swimming session, or keep a load closer to the body. Use forearm support during long desk tasks and a pillow when resting if helpful.

Dose and review
Apply to the tasks that reproduce symptoms; there is no fixed daily rest prescription.
Progression
Reintroduce height, repetitions and load one at a time as sleep and daily function improve.
Stop or reassess
Do not use activity modification to defer assessment of acute weakness, a hot swollen joint or new neurological findings.
Evidence and limits
Individualized education and activity modification are recommended in cuff care; this does not establish a trigger-point cause or require complete rest.

Exercise and rehabilitation

Build outward-rotation strength[3]

Consider when. An assessed cuff-related presentation that tolerates light resistance, without unexplained marked weakness.

With the elbow at your side and bent, rotate the forearm outward against a light band anchored on the opposite side. Keep the upper arm supported and return slowly; avoid rotating the trunk to finish the motion.

Dose and review
Example: 1–2 sets of 8–12 controlled repetitions on alternate days. This is a regional starting option, not a validated infraspinatus trigger-point dose.
Progression
Increase comfortable repetitions before band resistance; later train reaching and sport positions that matter to you.
Stop or reassess
Reduce load if pain or night symptoms remain worse afterward or the next day. Stop for sudden weakness, sharp joint pain or tingling.
Evidence and limits
Active resistance or motor-control rehabilitation is supported for cuff tendinopathy. No single exercise isolates a painful trigger point or has an established universal dose.

Exercise and rehabilitation

Restore comfortable reaching range[3][5]

Consider when. Pain-related movement restriction when gentle assisted motion is comfortable.

Rest the hand on a table and slide it forward as the body moves back slightly, staying within a comfortable shoulder range. Avoid forcing the arm behind the back or pushing a sleeper stretch into front-of-shoulder pinching.

Dose and review
Example: 5–8 slow slides once daily, individualized to response; this is not a muscle-specific trial protocol.
Progression
Gradually increase reach, then practice unassisted shelf-height tasks with a light object.
Stop or reassess
Stop for sharp catching or a progressively stiff joint; substantial passive restriction needs clinical assessment.
Evidence and limits
Regional active rehabilitation supports functional movement practice. The selected slide and dose are practical examples rather than proven trigger-point release techniques.

Clinician-delivered care

Consider a short clinician-led manual-therapy trial[3]

Consider when. Assessed shoulder pain where temporary comfort may help engage with exercise.

A clinician may trial comfortable soft-tissue or joint techniques, then repeat a chosen movement such as reaching or resisted rotation. Use this alongside a progressive exercise plan.

Dose and review
Time-limited trial; reassess function after treatment rather than scheduling an automatic series.
Progression
Transfer any improvement into active movement and taper passive care.
Stop or reassess
Stop if treatment causes neural symptoms or repeated relief fails to improve sleep, reaching or strength.
Evidence and limits
The cuff guideline allows manual therapy for short-term pain relief. Continue it when relief helps reaching or rotation during rehabilitation; evidence applies to cuff presentations rather than isolated infraspinatus points.

Reassessment and follow-up

  • Use the same shelf-reach or dressing task, plus nights disturbed by pain, as patient goals.
  • Compare outward-rotation force and pain separately using the same elbow position and resistance.
  • Track active and passive motion separately; new lag, wasting or increasing weakness warrants reassessment.
  • If appropriate active care does not improve function, reconsider tendon tear, stiff joint and cervical or suprascapular nerve causes rather than repeating local release.

Evidence and sources

  1. Calvo-Lobo et al. Dry Needling on the Infraspinatus Latent and Active Myofascial Trigger Points in Older Adults With Nonspecific Shoulder Pain

    2018 · Randomized clinical trial

    66 adults aged at least 65; one DN session treating active plus latent points versus active points alone. Short-term pain/PPT difference, no grip-strength advantage; no sham or exercise control.

  2. International Consensus on Diagnostic Criteria and Clinical Considerations of Myofascial Trigger Points: A Delphi Study

    2018 · Expert Delphi consensus

    Expert criteria and familiar symptom recognition; no diagnostic gold standard or fixed referral map.

  3. Rotator Cuff Tendinopathy Diagnosis, Nonsurgical Medical Care, and Rehabilitation: A Clinical Practice Guideline

    2025 · Clinical practice guideline

    Adults with suspected tendinopathy, including partial tears; full-thickness tears are outside its treatment scope.

  4. Neck Pain: Revision 2017

    2017 · Clinical practice guideline

    Neck classification, neurological screening, movement measures and multimodal rehabilitation; not a levator-specific treatment trial.

  5. Approach to Musculoskeletal Examination

    2021 · Clinical examination textbook

    Regional examination techniques; general movement and strength findings are not trigger-point diagnostic tests.

  6. Anatomy, Shoulder and Upper Limb, Infraspinatus Muscle

    2023 · Clinical anatomy reference

    Scapular origin, humeral attachment, suprascapular innervation and neuropathy clues.

  7. The Diagnostic Accuracy of Special Tests for Rotator Cuff Tear: The ROW Cohort Study

    2017 · Diagnostic cohort study

    208 people with shoulder pain; lag signs had low sensitivity and high specificity for cuff tear, not trigger-point pain.

  8. Diagnostic Value of Clinical Tests for Infraspinatus Tendon Tears

    2019 · Diagnostic study

    91 patients scheduled for arthroscopy; selected surgical population and inability to reliably distinguish partial from full tears limit generalization.

Associated Trigger Points