Section 01 of 20
Introduction
Trapezius is a large, flat, triangular muscle that covers the back of the neck, the upper back, and the top of the shoulders. The two trapezius muscles together form a diamond or kite shape across the upper back, running from the base of the skull down to the middle of the back and out to both shoulder blades.
It is usually described in three functional parts: upper fibers that slope down to the shoulder, middle fibers that run horizontally to the scapula, and lower fibers that angle up to the scapula. Together, these parts allow trapezius to move the scapula in almost every direction.
Section 02 of 20
Origin
| Origin | The external occipital protuberance and medial third of the superior nuchal line of the skull, the nuchal ligament, and the spinous processes of C7 through T12. |
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Section 03 of 20
Insertion
| Insertion | The lateral third of the clavicle, the acromion, and the spine of the scapula. |
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Section 04 of 20
Actions
| Primary action | Elevation, retraction, and depression of the scapula (by region). |
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| Secondary actions | Upward rotation of the scapula and postural support of the head and neck. |
| Movement at the joint | Scapulothoracic movement and the cervical spine. |
| Heads / fiber groups | Three functional parts: upper, middle, and lower fibers. |
| Functional examples | Shrugging; squeezing the shoulder blades together; reaching overhead; rowing; carrying a bag on one shoulder. |
Scapular elevation
The upper fibers lift the scapula, as in shrugging.
Scapular retraction
The middle fibers pull the scapula toward the spine.
Scapular depression
The lower fibers pull the scapula downward.
Upward rotation of the scapula
The upper and lower fibers work together to rotate the scapula so the arm can be raised overhead.
Section 05 of 20
Nerve Innervation
| Nerve | The accessory nerve (cranial nerve XI), with proprioceptive contributions from the anterior rami of C3–C4. |
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The accessory nerve travels through the posterior triangle of the neck, where it is vulnerable to injury during neck surgery or trauma. Weakness of shoulder shrugging on one side, or a drooping shoulder, may reflect accessory nerve involvement, not only muscle tightness.
Section 06 of 20
Blood Supply
| Blood | The transverse cervical artery, with contributions from the dorsal scapular artery. |
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Section 07 of 20
Pictures and Visual Anatomy
Section 08 of 20
Functional Movement
Trapezius is active in almost every arm and shoulder movement: shrugging, reaching overhead, rowing, carrying a bag on one shoulder, and holding good posture with the shoulder blades gently set. Its different fiber directions let it fine-tune the position of the scapula during complex movements.
Section 09 of 20
Synergists and Antagonists
Synergists: levator scapulae (elevation), the rhomboids (retraction and downward rotation), serratus anterior (upward rotation), and latissimus dorsi (depression). Antagonists: serratus anterior and pectoralis minor (protraction), and the rhomboids and levator scapulae oppose the lower fibers' downward rotation component in some movements.
Section 10 of 20
Palpation and Location
Client position and technique
Position the client prone or seated with the arms relaxed. Locate the base of the skull and follow the muscle down the neck, across the top of the shoulder, and down to the middle of the back. Ask the client to shrug the shoulders or squeeze the shoulder blades together to feel the different fiber directions engage.
Protect nearby structures
Use moderate, broad pressure over the fleshy parts of the muscle and lighter pressure at the base of the skull and along the top of the shoulder, where it is thinner. Avoid deep, sustained pressure at the base of the skull, and stop if the client reports dizziness, tingling, or sharp pain.
Section 11 of 20
Massage Therapy Relevance
The upper trapezius is one of the most commonly tense muscles in massage practice, especially with desk work, stress, and computer use. It is frequently involved in neck and shoulder tension and tension-type headache, though many other structures can contribute to these symptoms.
Section 12 of 20
Dysfunction: What Happens When Movement Goes Wrong
Changes in how a muscle works can change how a joint moves. The points below describe possibilities that may be associated with altered muscle function; they are not diagnoses, and one muscle is never assumed to be the sole cause of a problem.
When the muscle is weak
Weakness, especially of the middle and lower fibers, may be associated with rounded shoulders and poor scapular control during overhead reaching.
When it is tight or shortened
Tightness, especially of the upper fibers, may be associated with an elevated shoulder, neck stiffness, and tension headache.
When it is overused
Prolonged desk work, stress-related shoulder elevation, and repetitive shrugging may overload the upper fibers and may contribute to neck and shoulder pain.
When it is strained
A strain may cause sharp pain across the shoulder or upper back with lifting or sudden movement; cervical spine problems can look similar.
When it is inhibited or others compensate
Reduced activation, especially of the lower fibers, may be associated with poor scapular control and shoulder impingement symptoms during overhead activity.
When it does not coordinate well with synergists and antagonists
Poor coordination among the three trapezius regions and with serratus anterior may alter scapular movement and may be associated with neck or shoulder symptoms.
Section 13 of 20
Conditions, Pathologies, and Pain Relationships
Upper trapezius tension and trigger points
Prolonged desk work, stress, and a raised-shoulder posture may be associated with a tight, tender band across the top of the shoulder, sometimes with tension headache.
Scapular dyskinesis
Weakness or imbalance among the three parts of trapezius may be associated with abnormal scapular movement and shoulder discomfort during overhead activity.
Accessory nerve injury
Trauma or surgery near the neck can weaken trapezius, causing a drooping shoulder and winged scapula.
Differential considerations
Cervical disc and facet joint problems, rotator cuff conditions, thoracic outlet syndrome, and referred cardiac or pulmonary pain can all cause similar neck and shoulder symptoms.
Section 14 of 20
Example Clinical Relationship
A client who works long hours at a computer reports a tight, aching band across the top of both shoulders that spreads into a dull headache by the afternoon. The upper trapezius may be involved, and the pattern may be associated with postural tension, but cervical spine and nerve problems can look similar. Gentle, broad work across the shoulders and neck may support comfort, while a thunderclap headache, dizziness, or a drooping shoulder after injury needs referral.
Section 15 of 20
Massage and Treatment Approaches
For healthy, non-acute tissue, position the client prone or seated with the arms relaxed. Begin with broad effleurage from the base of the skull to the mid back, then use kneading and compression tailored to each region of the muscle, adjusting pressure for the thinner areas at the neck and the thicker mid-back fibers.
| Movement | Use gentle scapular elevation, depression, and retraction within comfort, and slow neck side-bending. |
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| Regional work | Consider levator scapulae, the rhomboids, the scalenes, and the suboccipitals when assessment supports it. |
| Avoid | Deep sustained pressure at the base of the skull, over an acute strain, or at any point that reproduces dizziness or arm tingling. |
Section 16 of 20
Precautions and Contraindications
Precautions and contraindications
- Recent neck or shoulder injury, suspected fracture, or recent neck surgery.
- Use caution with severe osteoporosis, anticoagulant use, or easy bruising.
- Avoid sustained pressure at the base of the skull and forceful neck movements.
- Stop if pressure causes dizziness, visual changes, tingling, or sharp pain.
Section 17 of 20
Red Flags and When to Refer
Red flags and referral
- Sudden, severe (thunderclap) headache, or a new headache unlike any before.
- Headache or neck pain with dizziness, vision changes, slurred speech, or facial numbness.
- A drooping shoulder or winged scapula after trauma or neck surgery.
- Neck or shoulder pain with fever, unexplained weight loss, or chest pain.
Section 18 of 20
Study Summary
Attachments
Origin: skull, nuchal ligament, C7–T12 spinous processes. Insertion: clavicle, acromion, and scapular spine.
Actions
Elevates, retracts, depresses, and upwardly rotates the scapula, by region.
Supply
Accessory nerve (CN XI), with C3–C4 proprioceptive fibers; transverse cervical artery.
Section 19 of 20
Instructor Narration
Open narration transcript
Trapezius is the large, kite-shaped muscle covering the upper back, neck, and shoulders, with upper, middle, and lower fiber groups.
It arises from the base of the skull, the nuchal ligament, and the spinous processes of C7 through T12, and inserts on the lateral clavicle, the acromion, and the spine of the scapula.
The upper fibers elevate the scapula, the middle fibers retract it, the lower fibers depress it, and together they upwardly rotate it. Levator scapulae, the rhomboids, and serratus anterior work with different parts of trapezius.
The accessory nerve, cranial nerve eleven, supplies it, with proprioceptive fibers from C3 and C4, and the transverse cervical artery provides its blood.
Palpate from the base of the skull down the neck, across the shoulder, and down to the mid back, asking for a shrug or a shoulder blade squeeze to feel each region engage. Use lighter pressure at the base of the skull.
Upper trapezius tension, scapular dyskinesis, and accessory nerve injury are relevant, and cervical, rotator cuff, and referred pain can overlap. Refer a thunderclap headache, headache with dizziness or vision changes, a drooping shoulder after trauma, or neck pain with fever.
Remember: skull and spine to the clavicle and scapula; elevation, retraction, depression, and upward rotation by region; accessory nerve.
Section 20 of 20