Supraspinatus

Origin, Insertion, Action, Innervation

Origin: Supraspinous fossa of the scapula (the concavity above the spine of the scapula)
Insertion: Superior facet of the greater tuberosity of the humerus, shoulder joint capsule
Action:
Primary: Initiates abduction of the shoulder (first 0°–15°)
Assists abduction throughout the range (compresses the humeral head into the glenoid, stabilizing it while the deltoid abducts)
Minor role in lateral rotation
Innervation: Suprascapular nerve (C5–C6)

Palpation Guide

Client position: Seated or prone.
Landmark sequence:

Locate the spine of the scapula by tracing from the acromion posteromedially.
Move your fingers superiorly above the scapular spine into the supraspinous fossa — the concavity between the scapular spine and the superior border of the scapula.
The supraspinatus fills this fossa. Palpate through the overlying upper trapezius — the supraspinatus lies deep.
Trace laterally — the tendon passes under the acromion and inserts on the greater tuberosity. The tendon is palpable with the arm in slight extension and internal rotation (hand behind the back) — this moves the greater tuberosity anteriorly, out from under the acromion.

Tissue feel: In the supraspinous fossa, it feels like a firm muscle filling a shallow bony groove. The tendon near the insertion feels like a firm cord. In tendinopathy, the tendon may be thickened and tender on the greater tuberosity.
Confirmation test: Ask the client to abduct the arm against resistance with the arm at the side (initiating abduction from 0°). The supraspinatus contracts in the fossa. Alternatively, use the empty can position (arm at 90° abduction, 30° horizontal adduction, thumb pointing down) against resistance — this is the standard isolation test.
Common errors:
Palpating the upper trapezius instead of sinking through it to reach the supraspinatus in the fossa.
Missing the tendon at the greater tuberosity — the tendon is the clinically relevant structure in tendinopathy, not just the muscle belly.
Confusing supraspinatus tenderness with subacromial bursa tenderness — the bursa overlies the tendon. Direct palpation cannot reliably distinguish the two.

Trigger Point Referral

Common TrP locations: A primary TrP in the mid-belly of the muscle, in the supraspinous fossa approximately midway between the medial scapular border and the acromion. A secondary TrP is near the musculotendinous junction as the tendon passes under the acromion.
Referral pattern: Refers deep aching to the lateral deltoid region and down the lateral arm to the lateral epicondyle. May also refer to the lateral shoulder.
Clinical significance: The lateral deltoid/arm referral mimics C5 radiculopathy distribution. If the client reports lateral arm aching with full cervical ROM and negative Spurling's test, palpate the supraspinous fossa — supraspinatus TrPs are a common non-radicular source of lateral arm pain.

Trigger point referral diagram — coming soon

Image coming soon. For visual reference, see [Supraspinatus at TriggerPoints.net](http://www.triggerpoints.net/muscle/supraspinatus).

Clinical Notes

Innervation significance:

The suprascapular nerve (C5–C6) passes through the suprascapular notch under the transverse scapular ligament. It is vulnerable to compression at this notch (suprascapular nerve entrapment), producing supraspinatus and infraspinatus weakness without pain.

Common conditions:

The most commonly torn rotator cuff muscle — the tendon passes through the subacromial space (between the acromion above and the humeral head below), making it vulnerable to compression, friction, and degenerative change. This is the central muscle in conditions/subacromial-impingement and conditions/rotator-cuff-tendinopathy.
The "critical zone" of the supraspinatus tendon (approximately 1 cm from the insertion on the greater tuberosity) is relatively avascular — poor blood supply makes this area prone to degenerative tearing and slow healing.
Partial and full-thickness tears are common with aging — many are asymptomatic. Imaging findings (MRI showing a tear) do not automatically explain the client's pain.
Involved in conditions/frozen-shoulder — adhesive capsulitis affects the joint capsule, but secondary supraspinatus inhibition occurs from pain and disuse.

What you'll typically find:

In clients with shoulder pain, the supraspinatus tendon is tender on the greater tuberosity in the majority of cases. This does not necessarily mean it is the primary pathology — the subacromial bursa, which overlies the tendon, is also commonly inflamed.
Painful arc during abduction (60°–120°) is the classic sign of supraspinatus tendon impingement. Pain at the initiation of abduction (0°–15°) suggests tendinopathy or tear.
Weakness on the empty can test is a significant finding — it suggests either a significant tendon lesion or neural compromise (suprascapular nerve).

Treatment effects:

Muscle belly TrPs in the supraspinous fossa respond to sustained compression and cross-fiber friction. Sink through the upper trapezius to access the deeper supraspinatus.
The tendon at the greater tuberosity responds to cross-fiber friction (Cyriax technique) — this promotes alignment of collagen fibers in tendinopathy. Apply with the arm in slight extension and internal rotation to expose the tendon anterior to the acromion.
Post-treatment, the painful arc often reduces in intensity. Full resolution of tendinopathy requires load management and progressive strengthening.

Cautions:

Avoid aggressive friction on the tendon in acute tendinopathy (hot, swollen, very irritable) — this worsens inflammation. Friction is appropriate for chronic tendinopathy with no acute inflammatory signs.
The subacromial bursa is superficial to the tendon — direct deep pressure on an inflamed bursa is very painful and counterproductive. If the client has bursitis, modify technique to avoid bursal compression.
Full-thickness rotator cuff tears are a relative contraindication for aggressive tendon friction — if the client has significant weakness on the empty can test and cannot maintain abduction against gravity, refer for imaging before applying heavy manual technique.

Postural significance:

In upper crossed syndrome, the scapula anteriorly tilts and protracts, reducing the subacromial space. This increases mechanical compression on the supraspinatus tendon during abduction. Correcting scapular position (strengthening lower trapezius, serratus anterior, and stretching pectorals) is essential for long-term supraspinatus health.

Clinical pearl:

The empty can test and the full can test (same position but thumb up) have comparable sensitivity for supraspinatus pathology, but the full can test is less painful. If the client is very irritable, use the full can position first. If strong and painless, supraspinatus is likely intact. If weak or painful, proceed with more specific testing.

Assessment

Manual muscle testing:

Empty can test (Jobe test): Client seated or standing. Arm at 90° abduction, 30° horizontal adduction (scapular plane), thumb pointing down (internal rotation). Apply downward pressure. Pain and/or weakness is positive for supraspinatus pathology.

Stretch test:

Horizontal adduction across the body: Client seated. Adduct the arm horizontally across the chest with the arm in internal rotation. This stretches the supraspinatus. Restriction is uncommon — the supraspinatus is more commonly weak than shortened.

Related special orthopedic tests:

Neer impingement test — passive flexion with scapular stabilization compresses the supraspinatus tendon
Hawkins-Kennedy test — internal rotation at 90° flexion compresses the tendon
Drop arm test — inability to slowly lower the arm from 90° abduction suggests a significant supraspinatus tear

Muscle Groups

Rotator cuff (anatomical):

Shoulder abductors (functional):

Supraspinatus (this article) — initiates abduction 0°–15°
anatomy/muscles/deltoid — primary mover 15°–90°

Suprascapular nerve group (innervation):

Supraspinatus (this article)
anatomy/muscles/infraspinatus

Related Muscles

Synergists for abduction:

anatomy/muscles/deltoid — middle fibers take over abduction after supraspinatus initiates
anatomy/muscles/infraspinatus — compresses the humeral head inferiorly to allow subacromial clearance during abduction

Antagonists:

anatomy/muscles/pectoralis-major — adducts the shoulder
Latissimus dorsi — adducts and internally rotates
anatomy/muscles/teres-major — adducts and internally rotates

Same innervation (suprascapular nerve):

anatomy/muscles/infraspinatus — shares C5–C6 suprascapular nerve; both are affected in suprascapular nerve entrapment

Key Takeaways

The most commonly injured rotator cuff muscle due to its passage through the narrow subacromial space and the avascular "critical zone" near its insertion.
Lateral arm pain with negative cervical findings suggests supraspinatus TrPs — check the supraspinous fossa before assuming radiculopathy.
The empty can test is the standard isolation test — weakness suggests significant tendon pathology or suprascapular nerve compromise.
Scapular position correction is essential — anterior tilt narrows the subacromial space and perpetuates tendon compression.