Muscle:Teres Major
Teres major is a relatively uncommonly involved myofascial muscle whose trigger points (TrPs) produce a deep, penetrating pain in the posterior deltoid region. Its clinical presentation is deceptive: patients compensate for the motion restriction without noticing it, pain at rest is usually mild, and the most consistent activating history is not a dramatic injury but a sustained ergonomic stressor — most characteristically, driving a vehicle without power steering. The muscle is anatomically and functionally inseparable from the latissimus dorsi, with which it almost always develops TrPs simultaneously; the two muscles share the posterior axillary fold, a common humeral insertion region, and a myotatic unit with the long head of the triceps brachii.
TrP tenderness was found in only 3% of 256 latent TrPs in the shoulder-girdle muscles of 200 healthy young adults, and in 7% of 126 active TrPs found in 80 older patients treated for shoulder pain — confirming that while involvement is real, it is genuinely less prevalent than most other shoulder-girdle muscles.
Anatomy
The teres major is a thick, flattened muscle that bridges the scapula to the humerus along the posterior and inferior aspect of the shoulder.
Medial (origin) attachment:
- Oval area on the dorsum of the scapula near the inferior angle
- Fibrous septa shared with the teres minor and infraspinatus muscles
Lateral (insertion) attachment:
- Medial lip of the intertubercular sulcus (bicipital groove) of the humerus
The borders of the teres major and latissimus dorsi tendons are joined for a short distance near their humeral attachments. The two tendons pass between the coracobrachialis muscle (anterior) and the long head of the triceps brachii (posterior). All fibres of the latissimus dorsi twist nearly 180° around the teres major as they converge toward the humerus; the superior (horizontal) latissimus fibres form the free margin of the posterior axillary fold, while the teres major lies deeper and more medially within it.
For its anatomical relation to the latissimus dorsi see Muscle:Latissimus_Dorsi; for its relation to other shoulder-girdle muscles see the subscapularis and posterior deltoid chapters.
Innervation: Spinal roots C5 and C6 via the posterior cord through branches of the lower subscapular nerve.
Primary actions:
- Medial rotation of the arm — only when resisted
- Adduction of the arm — strongly when adducting behind the back; weakly when adducting to the side unless the scapula is stabilised; only minimally activated when adducting across the front of the body
- Extension of the arm from the flexed position — when resisted
- Backward swing of the arm in walking
The teres major acts clinically as a synergist of the latissimus dorsi in the wood-chopping movement. It requires scapular stabilisation by the levator scapulae and rhomboids to fix the inferior angle before strong adduction can occur.
Referred Pain Patterns
TrP locations
Three trigger areas are described in the teres major:
- Midmuscle TrP — within the posterior axillary fold, where the latissimus dorsi wraps around the teres major (the most clinically accessible location)
- Posterior scapular (medial) trigger area — overlying the posterior surface of the scapula near the lateral border of its lower third
- Lateral musculotendinous junction trigger area — near the lateral musculotendinous junction as the muscle approaches the humerus
Referred pain pattern
Essential (solid) referral zone:
- Posterior deltoid region — deep, penetrating pain
Spillover (stippled) referral zone:
- Over the long head of the triceps brachii
- Into the posterior shoulder joint
- Occasionally the dorsal forearm
Must-absent features:
- Referral to the scapula — rare or never
- Referral to the elbow — rare or never
- Referral to the hand — not characteristic of teres major alone (distinguish from latissimus dorsi, which can refer to the ulnar hand)
Activation and Perpetuating Factors
The single most consistently identified activating stressor for teres major TrPs is driving a vehicle with heavy or non-power-assisted steering. The mechanism is force exerted from the top of the steering wheel turning toward the same side as the muscle — this is most likely to overload the muscle and activate its TrPs, particularly on the weaker non-dominant side.
A directly illustrative case: a driver had operated a large car without power steering for several years without shoulder problems. Oversized steel-belted radial tyres were then fitted to the front wheels in error, substantially increasing steering effort. Left teres major TrPs were activated and resolved only after returning to the correct tyre size and local injection.
Other activating activities:
- Reaching overhead and forward under load (e.g. serving in tennis)
- Lifting weights overhead
- Sustained typing with fatigue (EMG studies confirm moderate teres major activation during typewriter key strikes, increasing markedly with fatigue)
- Repeated rapid movement of the shoulder in the stretch position — stretch-irritation of TrPs perpetuates them; slow stretch with augmentation techniques releases them
Perpetuating factors:
- Sleeping on the affected side with the muscle in full shortening (arm adducted and medially rotated)
- Activities requiring sustained scapular stabilisation with rapid arm movement (instrument playing, throwing)
Clinical Examination
Range of Motion
The hallmark of teres major TrP involvement is that it does not freeze the shoulder and does not cause serious restriction of motion — but it does cause disabling pain near the full range. Patients routinely compensate for the slight restriction without noticing it.
Mouth Wrap-around Test (Fig. 18.2 in Travell & Simons):
- Restricted by 3–5 cm (approximately an inch or two) when only the teres major is involved. A larger restriction suggests additional involvement of the latissimus dorsi or other muscles.
Triceps Brachii Test (Fig. 32.4 in Travell & Simons):
- The patient cannot place the arm tightly against the homolateral ear when adducted above the head.
The muscle is provoked by:
- Passively flexing and laterally rotating the arm — stretches the teres major; reproduces pain
- Resisting active extension and medial rotation of the arm at the glenohumeral joint — loads the muscle; reproduces pain
Scapular Winging on Forward Reach
When the patient reaches with the arm in a forward position, scapular winging may appear that is not present with the arm at rest. The increased tension of the shortened teres major causes this, and it is evidence of the overload imposed on the middle trapezius, rhomboid, and serratus anterior muscles. This finding can implicate the teres major when other causes of winging have been excluded.
Glenohumeral and Acromioclavicular Joint Assessment
Shoulder pain with teres major TrPs may arise concurrently from glenohumeral or acromioclavicular joint dysfunction. Both joints should be tested for normal joint play in all cases.
Trigger Point Examination
Midmuscle TrP (axillary approach)
Positioning: Patient supine with the arm abducted to nearly 90° and laterally rotated.
Technique:
- Grasp the latissimus dorsi muscle mass between thumb and fingers — this muscle forms the free border of the posterior axillary fold as it wraps around the teres major
- Apply deep pincer palpation of the axillary fold a few centimetres (approximately 1 inch) below the arm to locate the axillary border of the scapula
- A groove is palpable between the edge of the scapula and the teres major muscle; this groove lies just above the point where the teres major extends beyond the scapula and joins the latissimus dorsi
- The teres major axillary TrPs are found just inferior to this groove
- Below the groove, at the level of the inferior angle of the scapula, only the latissimus dorsi forms the axillary fold — teres major is not present at this level
The teres major is the deeper (medial) of the two muscles within the axillary fold. At the level of the axillary TrP, the axillary fold is formed by both muscles, separated by the palpable groove.
Confirmation of teres major palpation: Instruct the patient to attempt to rotate the arm alternately medially and laterally against light resistance. The teres major tenses during medial rotation effort and relaxes with lateral rotation. This contraction test distinguishes teres major from latissimus dorsi.
Expected responses: Taut bands are readily located and local twitch responses felt and seen in all but the most obese patients.
Posterior scapular (medial) trigger area
Positioning: Patient lying on the uninvolved side with the uppermost arm resting on a pillow against the chest to ensure full muscle relaxation.
Technique: Locate the teres major in the axillary fold as above, then follow the muscle fibres posteriorly onto the scapula. Flat palpation against the posterior scapular surface reveals TrPs close to the lateral border of the lower third of the scapula.
Differential Diagnosis
Cardinal differentiating features of teres major TrP pain
| Feature | Present / Absent / Variable |
|---|---|
| Deep pain in the posterior deltoid region | Must be present |
| Pain on reaching forward and up | Must be present — the primary symptomatic complaint |
| Pain near full range without freezing the shoulder | Must be present — does not produce a frozen shoulder; distinguishes from adhesive capsulitis |
| Pain at rest | Usually mild — distinguishes from inflammatory arthropathy, where rest pain can be severe |
| Restriction of Mouth Wrap-around Test by 3–5 cm | Present when only teres major is involved — larger restriction implicates latissimus dorsi or other muscles |
| Referral to the scapula or elbow | Must be absent — if present, suspect other muscles (infraspinatus, triceps brachii) |
| Referral to the hand | Must be absent — hand referral points to latissimus dorsi (ulnar), infraspinatus (radial), or subscapularis |
| History of driving without power steering | Highly suggestive when present |
Comparison with the most important differential muscles
| Muscle | Referral zone | Key distinguishing features |
|---|---|---|
| Latissimus dorsi | Inferior scapular angle, midthoracic back, medial arm/forearm to ulnar hand (ring and little fingers) | Pain centred at the inferior scapular angle, not posterior deltoid; arm referral to ulnar hand; pain constant and unchanged by position; no provocative motion; innominate upslip possible |
| Infraspinatus | Anterior shoulder (essential), deep in glenohumeral joint, lateral arm, occasionally radial forearm and hand | Anterior shoulder pain; restricted internal rotation; referred pain to the radial (not ulnar) forearm; TrP in supraspinous/infraspinous fossa |
| Teres minor | Small, localised zone at posterior deltoid insertion area | Very limited referral; rarer; distinguishable by location of TrP (more superior and lateral on the scapula than teres major) |
| Posterior deltoid | Local posterior deltoid pain | TrP within the posterior deltoid bulk, not the posterior axillary fold; no restricted Mouth Wrap-around Test |
| Subscapularis | Posterior shoulder, band around wrist; axillary referral | Severely restricted internal rotation; TrP within the subscapular fossa; part of the pseudothoracic outlet quadrad |
| Triceps brachii (long head) | Posterior shoulder, posterior arm, lateral epicondyle area, dorsal forearm | Posterior arm pain; may include elbow and dorsal forearm; no Mouth Wrap-around restriction; often a satellite of teres major |
Confusingly similar structural diagnoses
| Diagnosis | Key differentiating features |
|---|---|
| Subacromial / subdeltoid bursitis | Painful arc on shoulder abduction (60°–120°); localised tenderness at the lateral acromion and greater tuberosity; positive Neer's or Hawkins–Kennedy impingement test; TrP examination of teres major does not reproduce bursal tenderness; imaging may confirm |
| Supraspinatus tendinitis / rotator cuff pathology | Painful arc; tenderness at the supraspinatus insertion on the greater tuberosity; weakness of resisted abduction at 0° in the scapular plane (empty can test); MRI or ultrasound confirms tendon pathology. Note: supraspinatus TrPs can produce a "impingement"-like picture — examine the muscle for TrPs before attributing symptoms to tendon pathology alone. |
| C6–C7 radiculopathy | Dermatomal sensory deficit in C6 (thumb, index finger) or C7 (middle finger) distribution; diminished biceps (C6) or triceps (C7) reflex; motor weakness in corresponding myotome; neuroimaging confirms disc or foraminal pathology. Teres major TrP pain does not produce reflex changes, dermatomal sensory loss, or myotomal weakness. |
| Thoracic outlet syndrome | Objective neurological deficit (typically lower trunk / T1: intrinsic hand muscle weakness and wasting, sensory deficit in C8/T1 distribution); vascular signs (diminished radial pulse with provocative manoeuvres, supraclavicular bruit, arm colour change). Teres major is one of the four muscles of the myofascial pseudothoracic outlet syndrome — see below. |
| Adhesive capsulitis (frozen shoulder) | Global restriction of glenohumeral motion in all planes, including passive range; capsular end feel; progressive restriction over months. Teres major TrPs cause pain near the full range but do not freeze the shoulder. However, if teres major TrPs go untreated and associated TrPs develop in the posterior deltoid, teres minor, and subscapularis, the combined picture can be diagnosed as frozen shoulder. |
Pseudothoracic Outlet Syndrome
The teres major is one of the four muscles constituting the myofascial pseudothoracic outlet syndrome. The other three are the latissimus dorsi, pectoralis major, and subscapularis. When at least three of these four muscles carry active TrPs simultaneously, their composite referred pain pattern strongly mimics thoracic outlet syndrome. These muscles cause no actual neurovascular compression.
See Muscle:Latissimus_Dorsi for the full differential criteria distinguishing pseudothoracic outlet syndrome from true thoracic outlet compression.
Entrapment
No nerve entrapment attributable to TrP activity in the teres major has been identified.
Treatment
Trigger Point Release
The teres major may be released in the supine position or with the patient lying partly on the uninvolved side (Fig. 25.4 in Travell & Simons).
Supine position:
- Affected arm placed in abduction with the elbow bent to provide control of lateral rotation
- After initial application of vapocoolant or icing, operator takes up the slack, allowing the arm to move into full lateral rotation and abduction by small increments, until the patient's hand can be placed behind the head
- The inferior angle of the scapula is stabilised by the patient's body weight
Augmentation techniques:
- Postisometric relaxation (contract-relax): most effective for this muscle
- Reciprocal inhibition: contraction of the antagonistic lateral rotators
Note on scapular stabilisation: The supine position makes scapular stabilisation easier; however, reaching the scapular portion of the muscle with vapocoolant spray is more difficult in this position. The semisupine position (partly on the uninvolved side) improves spray access at the cost of requiring additional support to maintain full patient relaxation.
After release, rewarm the skin at once with hot packs, then restore function with active range of motion against gravity.
The medial trigger area is well suited to trigger point pressure release — by the operator or by the patient using the Tennis Ball Technique (body weight over the tennis ball with the arm flexed to control tension).
The lateral trigger area is accessible to the patient's contralateral hand for manual digital pressure release.
Trigger Point Injection
Medial (posterior scapular) trigger area:
- Patient lying on the uninvolved side
- Approached from behind over the posterior aspect of the scapula — same approach as for infraspinatus injection, but more caudally (Fig. 25.5A)
Midmuscle TrPs:
- Patient supine, arm abducted to 90°
- Approached from the inside (anterior face) of the posterior axillary fold (Fig. 25.5B)
- TrPs identified within the posterior axillary fold and localised between thumb and fingers by pincer grasp
- Local twitch response felt on needle impalement confirms accurate TrP location
- The area is peppered with the needle — a cluster of TrPs is usually present
It is possible to inject adjacent latissimus dorsi TrPs through the same skin puncture by sliding the skin and needle laterally.
The patient should avoid strenuous effort of that muscle for several days following injection, and begin a daily home programme to maintain range of motion.
Scapular stabilisation in teres major treatment
The self-stretch of the teres major is performed like that of the latissimus dorsi (see Muscle:Latissimus_Dorsi); however, for full effectiveness it is essential to stabilise the scapula against abduction during the stretch — this is the key technical difference between the two stretches.
Note on Satellite TrP Relationships
Teres major TrPs drive secondary TrPs in functionally related muscles. These do not resolve until the teres major TrPs are inactivated first:
- Rhomboids — sustained tension and stretch from the shortened teres major causes interscapular pain attributed to the rhomboids; rhomboid TrPs may be refractory to treatment until teres major is addressed
- Posterior deltoid, teres minor, subscapularis — if teres major TrPs are left untreated, these muscles eventually develop associated TrPs, producing greatly impaired shoulder function — a presentation commonly diagnosed as frozen shoulder
The same secondary rhomboid pattern is also driven by pectoralis major TrPs; when rhomboid TrPs are refractory, both teres major and pectoralis major should be assessed as key TrP sources before treating the rhomboids directly.
Patient Education
Activity Modification
- Driving: Use a vehicle with power steering. If unavoidable, reduce steering effort and avoid prolonged sessions without breaks.
- Avoid lifting weights overhead during the active treatment phase.
- Avoid repeated rapid movements of the arm in the stretch position — these produce stretch-irritation that aggravates and perpetuates TrPs.
Sleep Position
To prevent full shortening of the teres major whilst sleeping on the affected side, place a small pillow between the elbow and the lateral aspect of the trunk to maintain a neutral muscle position (see Fig. 26.7 in Travell & Simons). A pillow support can also be used when sleeping on the uninvolved side (see Fig. 22.6A).
Home Stretching
- Begin by placing the painful arm behind the head (the starting position of the Mouth Wrap-around Test)
- Hold the arm with the other hand and release the teres major using the contract-relax technique
- Add reciprocal inhibition through self-resisted contraction of the antagonistic lateral rotators
- Perform under a warm shower with water over the teres major region to facilitate release
- Stabilise the scapula against abduction throughout — this is essential for full effectiveness and distinguishes this stretch from the latissimus dorsi stretch
Satellite Trigger Points
Muscles that commonly develop TrPs with or after teres major TrPs:
- Latissimus dorsi — anatomically and functionally inseparable; almost always involved together; treat as a unit
- Triceps brachii (long head) — myotatic unit member; commonly develops TrPs with teres major
- Rhomboids — secondary TrPs from sustained teres major tension; refractory until teres major is inactivated
- Posterior deltoid — develops associated TrPs in chronic or severe cases
- Teres minor — develops associated TrPs in severe cases contributing to frozen shoulder picture
- Subscapularis — develops associated TrPs in severe cases; pseudothoracic outlet quadrad member
Related Pages
- Muscle:Latissimus Dorsi — anatomically inseparable companion; always assess together; shares the posterior axillary fold and humeral insertion region
- Muscle:Triceps Brachii — myotatic unit; commonly co-active
- Muscle:Infraspinatus — key differential: anterior shoulder and radial hand referral vs posterior deltoid referral
- Muscle:Subscapularis — pseudothoracic outlet quadrad member; associated TrPs in severe cases
- Muscle:Pectoralis Major — pseudothoracic outlet quadrad member
- Muscle:Rhomboids — common secondary TrP target driven by teres major tension
- Pain:Posterior Shoulder Pain — diagnostic algorithm for posterior shoulder pain
References
- Travell JG, Simons DG. Myofascial Pain and Dysfunction: The Trigger Point Manual, Volume 1: The Upper Half of Body. 2nd ed. Baltimore: Williams & Wilkins; 1999. Chapter 25.