Human Movement Science & Functional Anatomy of the:

Trapezius

by Brent Brookbush DPT, PT, MS, PES, CES, CSCS, ACSM H/FS

This image was made out of, or made from, content published in a BodyParts3D/Anatomography web site This image was made out of, or made from, content published in a BodyParts3D/Anatomography web site

What’s in a name:

  • trapezius (n.) muscle over the back of the neck, 1704, from Modern Latin trapezius (musculus), masc. adjective from trapezium (see trapezium). (Etymology Online)

    • So called from the shape they form, as in tapeziod
    • trapezoid (n.) 1706, "a trapezium," from Modern Latin trapezoides, from Late Greek trapezoeides, noun use by Euclid of Greek trapezoeides "trapezium-shaped," from trapeza, literally "table" (see trapezium), + -oeides "shaped" (see -oid). Technically, a plane four-sided figure with no two sides parallel. But in English since c.1800, often confused with trapezium in its sense of "a quadrilateral figure having only two sides parallel and two not." (Etymology Online)

Attachments and Innervation:

Origin:

  • Upper: External occipital protuberance, medial 1/3 of superior nuchal line, ligamentum nuchae and spinous process of the seventh cervical vertebrae  (8, 11, 18).
  • Middle: Spinous processes and interspinous ligaments of C6 through T5 (8, 11).
  • Lower: Spinous processes and interspinous ligaments of the 6th thought 12th thoracic vertebrae (11).

    • Note: the vertebrae from which the middle and lower trapezius originate varies slightly between texts, for example, the most superior attachment of the middle trap may be listed as C5, C6 or C7 and the most superior attachment of the lower trap from T5, T6 or T7. This is likely due to a lack of physical division between segments and some disagreement between which fibers contribute to which joint actions.  The origins are simply an attempt to group motor units with similar functions together. The most superior and inferior attachments of the trapezius muscle are consistent between texts - listed as the superior nuchal line and the spinous process of T12.

Insertion:

  • Upper: Lateral 1/3rd of the posterior clavicle, superior acromioclavicular ligament, and anterior medial margin of the acromion.
  • Middle: Medial margin of the acromion and superior lip of the spine of the scapula (11).
  • Lower: From root of the spine of the scapula to a tubercle at the apex of the spine of scapula, extending laterally to the insertion of the middle trapezius via fibrous attachment (11).

Nerve: Spinal portion of cranial nerve XI (accessory nerve) with the trapezius portion of the motor nerve arising from the first 5 cervical segments, ascending through the foramen magnum and exiting the jugular foramen to supply and sometimes pierce the sternocleidomastoid before inserting into the trapezius muscle.  Some accessory fibers may be supplied by the ventral rami of C3 - C4 and sometimes C2; however it has not been determined what the functional significance of these separate neural innervations are. (8,11, 18 - 20).

Neural Innervation of Trapezius - http://legacy.owensboro.kctcs.edu/gcaplan/anat/images/Image471.gif

Action:

  • Upper:  Elevation, upward rotation and anterior tipping of the scapula.  Ipsilateral flexion, extension and contralateral rotation of cervical spine (3,8,11, 20).
  • Middle: Retraction of the scapula (3,8,11).
  • Lower: Depression, upward rotation and posterior tipping of scapula.

    • Note: Some texts note the potential for all portions of the trapezius muscle to contribute to retraction and upward rotation, and potentially combined contraction of all segments of the trapezius to contribute to head, neck and thoracic spine extension (8, 11, 20).

Note how the accesory nerve (CN XI) continues inferiorly to invest in the lower portions of the trapezius muscle - http://drkamaldeep.files.wordpress.com/2011/05/image10.png

Relative Location:

  • The trapezius is the most superficial muscle of the cervical spine, thoracic spine, and much of the scapula.  In this way the trapezius could be viewed similar to the gluteus maximus, the "big house," as both the largest muscle of the cervical and thoracic spine and in that it "covers" many of muscles of the cervical and thoracic spine.  The upper trapezius originates on the medial 1/3 of the superior nuchal line by investing in a fascial sheath that is shared by the posterior fibers of the sternocleidomastoid and may potentially continue superiorly to the occipitalis muscles. In the space between the lateral border of the upper trapezius and posterior border of the sternocleidomastoid (the posterior triangle of the neck - pictured below)  the splenii, the levator scapulae and posterior scalenes may be palpated (listed in order form superior to inferior). Deep to the upper most fibers of the trapezius, at the base of the occiput, are two additional layers of muscle - the semispinalis capitis is just deep to the upper trapezius and the suboccipital muscles are deep to the semispinalis capitis. As the trapezius muscles course down the spine they also cover the semispinalis cervicis, the cervical and thoracic erector spinae, and the deeper extensors of the spine: the multifidusrotatores, interspinalis and intertransversarii.  As the upper trapezius courses laterally toward the clavicle and acromion it envelops the levator scapulae and the lower portions of the posterior and middle scalenes, covering the posterior portions of the 1st and 2nd rib, as well as, a portion of the brachial plexus.

Posterior Triangle of Neck - https://classconnection.s3.amazonaws.com/33/flashcards/602033/jpg/posterior_triangle_schematic_(black_triangle)1315803074585.jpg

  • The middle trapezius includes the fibers originating from vertebrae C6 to T5 and inserting from the middle 1/3 of the superior lip of the spine of the scapula to the medial margin of the acromion. The middle trapezius courses over many muscles (listed from medial to lateral): as mentioned above, the trapezius muscles cover the cervical and thoracic erector spinae, and the deeper extensors of the spine: the multifidusrotatores, interspinales and intertransversarii, the middle trap continues to course over the rhomboids (and the deeper serratus posterior superior), then the superior angle and root of the spine of the scapula, the origin of the levator scapulae, and finally completely envelope the supraspinatus (lying in the supraspinous fossa).  Palpation of the supraspinatus and origin of the levator scapulae may be achieved, but only through the fibers of the middle trapezius. At its origin, the middle trapezius invests in a cervicothoracic fascial sheath that may be worth further investigation - studies have noted a relationship between thoracic spine stiffness, middle trapezius and rhomboid trigger points with lasting treatment only occurring after addressing postural issues and thoracic spine stiffness (8).

Superficial and Deep muscles of the Posterior Thorax - https://classconnection.s3.amazonaws.com/1211/flashcards/716464/jpg/posteriorthoracic.jpg

  • The lower trapezius include those fibers originating from T6 - T12 and inserting from the root of the spine of the scapula medially to the insertion of the middle trapezius on the middle 1/3 of the spine of the scapula laterally.  The superior portion of the lower trapezius lies superficial to the rhomboids and the inferior portions lies superficial to the serratus posterior inferior.  A small portion of the latissimus dorsi originates from underneath the tail end of the lower trapezius, just as a small portion of the infraspinatus lies underneath the most lateral fibers.  As with the upper and middle trapezius the lower trapezius covers the thoracic erector spinae, and the deeper extensors of the spine: the multifidusrotatores, interspinalis and intertransversarii.

    • Although more relevant to manual therapists, it is worth noting that reaching the subscapularis via palpation from the medial side involves palpating through and stretching the rhomboids and lower trapezius around the vertebral border of the scapula - unless getting under the scapula is first achieved at the triangle of auscultation.

Posterior trunk of a cadaver with Triangle of Auscultation - By Daniel G. Bates - Visible Human Male, dissection created using the VH Dissector and further editted, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=11375322

Palpation:

  • Upper Trapezius: The surprisingly slender upper trap may be palpated from the base of the skull to the base of the neck and across the top of the shoulder girdle.  With your partner in prone, gently squeeze the most superficial layer of muscle at the upper cervical spine.  Have your partner lift their head - you should feel the density of this layer quickly increase as the upper trap contracts - follow those same fibers down across the top of the scapula. Having your partner gently elevate and relax their shoulder girdle as you palpate may help you trace the fibers from the base of the neck to lateral clavicle (14).  Note: if you feel too deep when palpating the traps at the cervical spine you will be palpating the splenii.  These muscles are easy to identify, they feel like two near-vertical bars or cylinders of muscle. They course up and down the back of the neck, and do not course over the shoulder girdle.
  • Middle Trapezius: With your partner still in prone, find the spine of the scapula.  Move your hand medial to the spine of the scapula; asking your partner to retract should "pop" the middle trapezius into your fingers.  Remember these are superficial fibers, if you dig too deep you may palpate through the middle trap to the deeper rhomboidserector spinae or levator scapulae (14). To inhibit the rhomboids and levator scapulae, have your partner start with their hands by their forehead.  Retracting in this position (scapular upward rotation) will result in less activation of the rhomboids and levator scapulae.

Bodybuilder showing-off incredibly hypertrophied Trapezius muscles - http://www.musclesused.com/wp-content/uploads/2012/08/Trapezius-Muscle-3.jpg

  • Lower Trapezius:  Palpate the lateral border of the very superficial lower trap with your partner in prone (try to visualize the shape of the muscle - "Trapezoid or Kite Shaped").  You may be able to get your fingers underneath the lower trap and gently lift it from underlying musculature.  If you are having a difficult time locating the lateral border of the lower trapezius, have your partner raise their hand out in front of their head while cuing depression, as pictured below (same position as a lower trapezius manual muscle test (MMT)) - this should result in a strong contraction of the lower trapezius (14).  Make sure to palpate the border of the lower trapezius all the way to its origin on the spinous process of T12.  Many new students, and professionals alike, are surprised at just how low the lower traps go.

Palpating the Lower Trap - http://i.ytimg.com/vi/-mJlHb_9_xs/hqdefault.jpg

Integrated Function:

  • Stabilization: AC Joint (10), reinforcement of the acromioclavicular ligament, stabilization of the scapula (acromioclavicular and sternoclavicular joints respectively), stabilization of the atlanto-occipital joint, cervical spine and thoracic spine.
  • Eccentrically Decelerates:  All segments of the trapezius muscle may eccentrically decelerate protraction and downward rotation.  Additionally, the lower trap may eccentrically decelerate elevation and anterior tipping, and the upper trap may decelerate depression and posterior tipping.
  • Synergists:

    • The upper trapezius, levator scapulae and rhomboids work synergistically during elevation.
    • The middle trapezius (with some assistance from the upper and lower trapezius) and rhomboids act synergistically during retraction.
    • The lower trapezius and pectoralis minor act synergistically during depression.
    • The upper trapezius, lower trapezius and serratus anterior work synergistically during upward rotation of the scapula, with increasing contribution by the middle trapezius the more the arm is elevated.
    • The upper trapezius may aid the pectoralis minor and levator scapulae in anterior tipping of the scapula (this synergy plays a major role in Upper Body Dysfunction (UBD)).
    • The lower trapezius and serratus anterior act synergistically to posteriorly tip the scapula (this synergy plays a major role in Upper Body Dysfunction (UBD)).

By Anatomist90 (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons By Anatomist90 (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

Arthrokinematics:

      • All of the muscles that move the scapula have an affect on acromioclavicular (AC) and sternoclavicular (SC) arthrokinematics, but the relationships are indirect and may vary depending on the intended motion, synergies recruited, compensation patterns present, and potentially individual differences in the shape of joint surfaces (16).

        • The AC Joint: The AC joint is primarily responsible for rotational movements (upward and downward rotation), and those movements that fine tune how the scapula lies on the rib cage (internal/external rotation and anterior/posterior tipping) (3).

          • I could not find a single reference regarding the affect the trapezius muscle may have on arthrokinematic motion of the acromioclavicular (AC) joint.  However, based on common dysfunction, clinically effective mobilization techniques, and EMG studies we may be able to presume that optimal motion of the acromion on the clavicle follows convex on concave rules in the sagittal plane (slide opposite roll), concave on convex in the frontal plane (slide follows roll), and deduce that relative inhibition of the trapezius muscles contributes to alterations in these arthrokinematics and dyskinesis.  That is, excessive downward rotation, anterior tipping and internal rotation of the scapula are common in those individuals with Upper Body Dysfunction (UBD), and to aid in correcting impairment at the AC joint, many clinician's use posterior to anterior mobilizations and superior to inferior mobilizations applied on the distal clavicle.  This could imply that the acromion has a propensity toward, inferior glide, and increased compressive forces relative to the distal clavicle, and that pushing inferior and anterior on the clavicle relative to a stable scapula results in better congruence.  Further, a study by Lawrence et. al, demonstrated less relative posterior rotation of the clavicle (and upward rotation of the scapula) in those individuals with shoulder impingement (16), which may imply an increase in anterior roll of the acromion on the clavicle (relative motion).  Last, a study by Scovazzo et. al. (15), showed an overall decrease in trapezius activity in swimmers with shoulder pain and/or impairment, which may result in less force directed medially, relative external rotation and potentially lateral glide of the acromion on the scapula.  In summary, a model of arthrokinematic dyskinesis for the AC joint may include excessive inferior and lateral glide, anterior roll and an increase in compressive forces.  As the upper trapezius anteriorly tips the scapula, it may be implied that movement impairment results in, or is the result of, an over-active upper trapezius contributing to excessive inferior glide and anterior role of the acromion on the clavicle; however, that would be an incomplete hypothesis.  Remember, the upper trapezius attaches to both the acromion and the lateral third of the clavicle, and several authors have implied that the upper trapezius may actually be under-active in those individuals with shoulder girdle dysfunction (3, 7, 15). It is my hypothesis that that the role of the upper trapezius in arthrokinematic motion of the AC joint is to ensure that both joint surfaces (clavicle and acromion) elevate simultaneously with the anterior fibers contributing to optimal clavicular posterior rotation during elevation of the arm. Further, movement impairment of the shoulder girdle results in relative inhibition of the upper trapezius (prime mover of upward rotation) and synergistic dominance of the rhomboids and levator scapulae.  This leads to upward rotation being replaced by elevation accompanied by downward rotation and anterior tipping.  The resulting arthrokinematic dyskinesis would be as described above (excessive inferior glide, anterior roll, lateral glide and increase in compressive forces of the acromion on the clavicle).
          • The middle trapezius applies a medially directed force; this would result in medial glide of the acromion on the clavicle and external rotation of the scapula.  Many author's and clinicians assume that this muscle is long and under-active (1-4, 7, 15), adding congruence to the model of optimal motion and dyskinesis described above. Note: Lateral to medial mobilization of the scapula on the clavicle does not seem to be particularly effective; the best way to decrease external rotation and lateral glide of the acromion on the clavicle is likely best achieved by increasing recruitment and activity of the middle trapezius (see Trapezius Activation Video below).  As the middle trapezius has a line of pull that is more-or-less through the center of the axis of rotation in both the frontal and transverse planes it is unlikely that it can contribute to inferior/superior glide or anterior/posterior roll.
          • The lower trapezius applies an inferiorly directed force on the medial 1/3 of the spine of the scapula making it a strong depressor, posterior tipper, upward rotator, and potentially external rotator of the scapula.  The effect on arthrokinematics would be similar to the upper trapezius, but due to a separate set of forces.  The posterior tipping resulting from lower trapezius activation would reduce anterior roll of the acromion on the clavicle by matching the posterior rotation of the clavicle.  The depression combined with upward rotation created by the lower trapezius would reduce the propensity toward elevation and downward rotation noted in shoulder girdle dysfunction, and may help optimize the rate of elevation of the acromion reducing inferior glide.  The lower trap's contribution to external rotation, posterior tipping and medial glide would likely reduce compressive forces and lateral glide of the acromion on the clavicle.  In short, the lower trap may be an important synergist for optimizing scapular position and concurrently arthrokinematics of the acromion on the clavicle, during elevation of the arm.

Henry Vandyke Carter , via Wikimedia Commons Henry Vandyke Carter , via Wikimedia Commons

  • The SC Joint: The SC joint allows motion in all three planes contributing to protraction/retraction in the transverse plane, elevation/depression in the frontal plane, and rotation along the clavicles longitudinal axis (3).  As the SC joint is a saddle joint, convex on concave rules apply in the frontal plane (slide opposite roll), while concave on convex rules applied in the transverse plane (slide follows role) (3).  Longitudinal rotation of the clavicle follows the direction of scapular tipping and would incorporate spin in the same direction at the proximal clavicle.

      • Upper Trapezius: The upper trap's contributions to sternoclavicular (SC) joint arthrokinematics are far simpler than those described for the AC joint.  As described above, the upper trapezius likely contributes to posterior rotation of the clavicle via anterior fibers that insert into the clavicle, which would result in posterior spin at the SC joint. Optimal arthrokinematic motion of the SC joint in the frontal plane should follow convex on concave rules, implying that the upper trap's contribution to clavicular elevation should result in inferior glide of the clavicle at the sternum.  Dyskinesis of the sternoclavicular joint may be a result of a decrease in upper trapezius activity and a decrease in posterior rotation (described above); disrupting joint surface congruence and forcing superior glide during elevation.  More research is needed.
      • The middle and lower traps likely affect SC joint arthrokinematics as synergists for optimal scapular motion.  The most relevant contribution to SC joint arthrokinematics is likely related to posterior tipping of the scapula, matching (and not restricting) posterior rotation of the clavicle and concurrently the SC joint.  It may be interesting to devise a study that determined the importance of the medially directed force created by the middle and lower traps on the scapula, the transfer of that force to the clavicle and the effect it has on SC joint arthrokinematics.  Even the contribution of a medially directed force to compression of the SC joint may be important to SC joint stabilization.

The articular surfaces of the sternoclavicular (SC) joint - Convex-on-Concave (slide opposite roll) in the frontal plane & Concave-on-Convex (slide follows roll) in the transverse plane - https://classconnection.s3.amazonaws.com/184/flashcards/1904184/png/11353978907868.png

  • The Cervical and Thoracic Spine: The spine is comprised of gliding joints (facet joints) whose motion could be described as arthrokinematic motion (superior, inferior, lateral and medial glide) at each facet that results in osteokinematic motion (flexion, extension, lateral flexion and rotation) when the movement at each joint is summated.   For example, extension is nothing more than the combined inferior glide of all facets at several segments of the spine.  "Closing" and "opening" of facets is often described relative to manual therapy in which extension, ipsilateral flexion and ipsilateral rotation results in maximal congruence of facet joint surfaces and flexion, contralateral flexion and contralateral rotation results in minimal congruence of joint surfaces.

      • Upper Trapezius: The effect of the upper trapezius on the cervical spine includes extension, ipsilateral flexion and contralateral rotation, which results in maximal closure of the neural foramen, but does not result in complete closure of the facet joint.  Significant closure does result from extension and ipsilateral flexion, but contralateral rotation actually "opens" facets slightly.  Raising the arm does result in contraction of the ipsilateral upper trapezius, as well as, a slight contraction of the contralateral upper trapezius (7).  This is likely due to the inherent mobility of the cervical spine and the ability of the upper trap to rotate the cervical vertebrae to the opposite side via attachment to the ligementum nuchae and the force imposed on the spinous process.  It is not uncommon for cervical facet joint dysfunction to result in trigger points and altered activity of the upper traps.  Resolution and normalization of upper trapezius activity is dependent on not only release of the upper trapezius, but mobilization of stiff facets and optimization of cervical arthrokinematics.

By Dr.foksha (Own work) [CC BY-SA 4.0 (http://creativecommons.org/licenses/by-sa/4.0)], via Wikimedia Commons By Dr.foksha (Own work) [CC BY-SA 4.0 (http://creativecommons.org/licenses/by-sa/4.0)], via Wikimedia Commons

      • The Middle and Lower Trapezius: may rotate the thoracic spine to the opposite side if the scapula is fixed or the arm is resisted by a significant force.  Further, arthrokinematic dyskinesis of thoracic facets may result in relative inhibition of the middle and lower trapezius (arthrokinematic inhibition).  Mobilization and manipulation of the thoracic spine has been found to be clinically effective in improving recruitment of inhibited upper and lower traps.  It may be worth considering that a kyphotic posture would increase the length of both the middle and lower trap and may be a contributing factor to thoracic, scapular and glenohumeral dyskinesis and pathology.
      • The trapezius muscle as a whole:  There is some evidence to suggest that the trap may contribute to cervical and thoracic extension when the muscle is activated as a whole, especially when the scapula is fixed - an example may include prone press ups on elbows. Mobilizations/manipulations are often used in treating the thoracic spine in those individuals who exhibit a kyphotic posture - could it be that trapezius activation would be appropriate for maintaining a  more erect posture and improving stabilization of thoracic facets post mobilization/manipulation?

Fascia - https://commons.wikimedia.org/wiki/File:Illu_connective_tissues_1.jpg Fascia - https://commons.wikimedia.org/wiki/File:Illu_connective_tissues_1.jpg

Fascial Integration:

My Fascial Hypothesis: Large fascial sheaths not only play a role in the transmission of mechanical force, but may also play a role in dictating the function of muscular synergies. This is likely caused by reducing or increasing tone of invested musculature via reflex arcs formed between mechanoreceptors embedded in the connective tissue and the attached musculature. In this way my view of fascia differs slightly from noted expert on the subject Tom Myers. I think of these large fascial sheaths (specifically the thoracolumbar fascia, iliotibial band, and abdominal fascial sheath) as natures “mother board.” A place for mechanical information to be communicated to the nervous system for more efficient recruitment of the muscular system. Despite having a slightly different philosophy it does not change the fact that fascia plays an important communicative role in the human body and we have Tom Myers to thank for his work.

Ligamentum Nuchae - Primal Pictures

  • Superficial/Investing Cervical Fascia and the Superior Nuchal Line:  An interesting relationship to explore would be the shared fascia of the sternocleidomastoid (SCM) and upper trapezius. This sheath of fascia extending just inferior to the superior nuchal line, and expanding from external occipital protuberance medially to mastoid process laterally.  This fascia is an expansion of the superficial cervical fascia, is invested by the ligamentum nuchae and may extend superior to invest in the fascial origin of the occipitalis.  As the sternocleidomastoid is often over-active and the upper trapezius under-active the relationship is puzzling, although in the extremes of forward head posture and cervical dysfunction the upper trap, SCM and the investing muscles of the ligamentum nuchae may all present with trigger points and increased tone.

    • As I combed through pictures and texts researching potential relationships, I did come to an interesting conclusion.  The occipitalis and galea aponeurotica likely have fascial continuity with the structures mentioned above - despite all of the illustration of the occipitalis and galea aponeurotica implying a fascial connection with the deeper splenii and sub-occipitals.  The splenii and sub-occipitals are actually enveloped by a deeper layer of cervical fascia (prevertebral layer). How do fascial lines bypass the the superficial fascia, the upper trapezius and the ligamentum nuchae to affect tension in the prevertebral fascia? - Somebody e-mail Tom Myers, this one has me scratching my head.

http://en.academic.ru/pictures/enwiki/78/Nuchal_lines.png

  • Ligamentum Nuchae: The ligamentum nuchae in quadrupedal animals is known as the paddy-whack - fun fact of the day ;-)  Four muscles insert into the strong ligamentous expansion of the posterior cervical spine known as the ligamentum nuchae (pictured above).  This includes the superficial upper trapezius, as well as, the rhomboids minor, splenius capitis and serratus posterior superior.  This fascial sheath has also been found to have direct fibrous attachments with the spinal dura between the occiput and C1, and between C1 and C2 (17), which may have clinical significance in the treatment of cervicogenic headache.  The splenius capitis and rhomboids minor have a tendency toward over-activity, and the upper trapezius may present as over-active (although less often) with trigger points. The same may be true of the serratus posterior superior (although difficult to determine due to the muscles small cross-section, function and depth). Forward head posture would result in increased tension in the ligamentum nuchae - Could this increase in fascial tension stimulate receptors that facilitate activity of investing musculature, and potentially the hypertonicity in cervical extensors noted clinically?

By Henry Vandyke Carter - Henry Gray (1918) Anatomy of the Human Body (See By Henry Vandyke Carter - Henry Gray (1918) Anatomy of the Human Body (See "Book" section below)Bartleby.com: Gray's Anatomy, Plate 384, Public Domain, https://commons.wikimedia.org/w/index.php?curid=561537

  • Thoracocervical Fascia:  Certainly more research is needed investigating the complex relationship between the fascia and investing musculature at the cervicothoracic junction. The upper and middle trapezius share some common fascial tissue at their origin on the spinous process and ligamentum nuchae with the rhomboids, splenius capitis, and serratus posterior superior, but what about deeper layers of the cervicothoracic fascia.  The prevertebral layer of the cervical spine must extend inferiorly to envelop the extensors of the thoracic spine, but how intimate is this fascial layer with the more superficial cervicothoracic fascia.  As this segment of the spine and the associated ribs have a complex role to play in the optimal motion of the scapula and shoulder, there could be a functional purpose for complex synergies. It has already been mentioned several times throughout this article that dyskinesis of the cervical and thoracic spine may result in altered activity and trigger point development in the trapezius muscles.  Could there be synergistic subsystems at the cervicothoracic junction, analogous to those found crossing the lumbar spine and investing in the thoracolumbar fascia?
  • Trapezius and Deltoids (Anatomy Trains = Superficial Back Arm Line (6)).  Fascial continuity between the insertion of the trapezius muscle and the origin of the deltoids, is actually one of the simpler relationships and stronger arguments for fascial lines if you consider these muscles relative to scapulohumeral rhythm.  Consider how elevation of the arm includes both activation of the deltoids and the trapezius to initiate upward rotation of the scapula.  The strongest fascial connection is likely from the upper trapezius to superior AC ligament to anterior deltoid (10).  A relationship that is highlighted every time we reach for something - shoulder flexion via the anterior deltoid accompanied by upward rotation of the scapula via the upper trapezius.

Behavior in Postural Dysfunction:

The lower and middle trapezius have been noted as long and under-active by many clinicians, texts and studies (1, 2, 4, 7, 8, 11, 15, 21).  The upper trapezius has been noted as both under-active (3, 7, 15, 21) and over-active (1, 2, 5, 8) leading to some confusion on the affect this muscle may have on upper body dysfunction/impairment.

In Upper Body Dysfunction (UBD)  –

The lower trapezius is most often long and under-active leading to excessive elevation, downward rotation and anterior tipping of the scapula in both static and dynamic postures.  Manual muscle testing (MMT) will often highlight marked weakness in those with shoulder, shoulder girdle and thoracic spine pathology.  Occasionally trigger points are noted, but these are relatively rare when compared and/or differentiated from rhomboid trigger points and/or arthrokinematic dysfunction of the lower thoracic spine resulting in facilitation of the lower traps.

The middle trapezius plays a similar role in postural dysfunction/movement impairment as the lower trapezius, resulting in a decrease in end range upward rotation during arm elevation and anterior tipping during postural assessment.  Careful attention should be given to the relationship between the thoracic spine and middle trapezius.  Dysfunction of one, is often a sign of dysfunction in the other.

It is my hypothesis that the upper trapezius may be over-active in those with the extremes of shoulder girdle and cervical dysfunction, contributing to both extension of the upper cervical spine and anterior tipping of the scapula.  However, it is more common to find the upper trapezius long and under-active, leading to a decrease in scapular upward rotation and clavicular posterior rotation during arm elevation.  Evidence of under-activity in the upper trapezius has been noted in a study by Scovazzo, who examined the muscle activity of freestyle swimmers with a painful shoulder - trapezius activity was shown to be reduced during all phases of the swimming stroke (15).  In postural assessment (for example, the Overhead Squat Assessment), under-activity of the upper trap generally results in elevation of the superior angle of the scapula (shoulder girdle elevation) around a fixed glenoid fossa - relative downward rotation. The elevation is actually due to the activity of the levator scapulae and rhomboids, acting as overactive synergists for an inhibited upper trapezius.  If the upper trapezius was the cause of the observable elevation of the shoulder girdle during assessment it would be accompanied by upward rotation.

Brent's HMS Rule #3:  Every joint motion is relative. That is one bone moves relative to the other.

Why do you keep referring to downward rotation of the scapula in UBD,  when I clearly see the scapula elevate during assessment?

It’s an optical illusion, kind-of…  What you see is the superior angle (superior/medial corner) of the scapula elevate, but the glenoid fossa remain fixed.  That is to say, downward rotation of the scapula can occur as it is traditionally taught – glenoid fossa moving inferiorly, or as elevation of the superior angle of the scapula around a fixed glenoid fossa.

The diagram below depicts a posterior view of the right scapula and humerus.  The image on the left depicts downward rotation as it is “traditionally” taught, while the diagram on the left depicts relative downward rotation around a fixed glenoid fossa (downward rotation masquerading as elevation).

Note: scapular downward rotation around a fixed humerus is relative humeral abduction indicating a decrease in length of the supraspinatus and posterior deltoid.

In similar fashion to the example above, the forward motion often noted as protraction may be viewed as anterior tipping and protraction of the upper scapula alone around a fixed inferior angle.

The Upper Trapezius is one of the few "Jekyll and Hyde" muscles.  That is, most muscles that have a propensity toward over-activity are almost always over-active, and those muscles with a propensity toward under-activity are almost always under-active.  It would seem that despite my inclination to label this muscle long/underactive, the upper trapezius may play both roles.  This is not unheard of, as some of the muscles of the core may also play both roles (for example, the Psoas).

Travell and Simons note the upper trapezius may be the the most common site for trigger point development (8).  In light of this evidence, it may be easiest to simply lump the upper trap in with the other over-active, trigger point laden muscles, but we cannot forget that long muscles can have trigger points too.  What if the upper trap is acting like the biceps femoris in Lumbo-Pelvic Hip Complex Dysfunction (LPHCD) - Long and Over-active. Consider how changing length/tension relationships results in decreased force production and efficiency, and the affect that may have on a long upper trap trying to resist gravity's pull on the entire shoulder girdle.  Could trigger points be a compensation to overcome the loss in force production and maintain some level of scapular stability?

Last, there may be some confusion related to the source of trigger points.  If you return to the "Relative Location" section of this article you may note that the upper trapezius lies over several muscles that are commonly over-active.  Namely, the levator scapulae, rhomboids and supraspinatus, and that many clinicians have noted a resolution of trigger points with cervical and thoracic mobilization.  Before one advocates release and stretching for a muscle that may be either under-active or over-active, it may be prudent to check other structures that may contribute to dysfunction.

In Lumbo Pelvic Hip Complex Dysfunction (LPHCD) and Sacroiliac Joint Dysfunction (SIJD) the trapezius muscle plays no significant role.

In Lower Leg Dysfunction (LLD) the trapezius muscle play no significant role.

In Short, all segments of the trapezius muscle may have a propensity toward under-activity and an adaptive increase in length.  This implies that activation, integration and strengthening techniques should be part of a human movement professional's repertoire. The upper trapezius may be over-active in those individuals with the extremes of cervical and Upper Body Dysfunction (UBD) and additional techniques used to reduced tone and increase length (release and stretching) will be necessary for this segment of the muscle. Last, knowledge of cervical and thoracic mobilization techniques maybe useful for long-term resolution of altered activity and length (see videos below).

http://www.rvuanatomy.com/uploads/1/3/4/5/13457421/sb4a-edited.gif

Clinical Implications:

      • Trapezius trigger points
      • Cervical Pain
      • Thoracic Pain
      • AC Joint Pain
      • SC Joint Pain
      • Cervicogenic Headache
      • Cervical Radiculopathy
      • Shoulder impingement
      • Bursitis
      • Thoracic Outlet Syndrome
      • Scapular winging
      • Anterior shoulder laxity
      • Osteoarthritis

        • Thoracic Spine
        • AC Joint
        • SC Joint
        • Glenohumeral Joint

Signs of Altered Length/Tension and Tone:

    • Goniometric assessment of the scapula is unreliable, although observation of scapular movement during arm elevation may provide valuable information.
    • Cervical Lateral Flexion: < 35° (Upper Trapezius Only)

Tapezius Trigger Points:

It is my humble opinion that many trigger points believed to be trapezius trigger points, are actually levator scapulae, supraspinatus and rhomboid trigger points.  Further, some trigger points in the trapezius are nothing more than satellite sites originating from the cervical and thoracic spine dysfunction (arthrokinematic facilitation).

  • Palpation results in tenderness and may result in radiating symptoms.

upper-trapezius-trp-combined David G. Simons, Janet Travell, Lois S. Simons, Travell & Simmons’ Myofascial Pain and Dysfunction, The Trigger Point Manual, Volume 1. Upper Half of Body: Second Edition,© 1999 Williams and Wilkens

Comparison of Upper Trapezius, Levator Scapulae and Rhomboid trigger points (listed from superior to inferior) with posterior deltoid trigger point marked on male subject:

Upper Body Trigger Points

Techniques for optimizing trapezius length and activity:

Trapezius Activation:

Trapezius Reactive Activation:

Self-administered Upper Trapezius Release:

Self-administered Upper Trapezius Statice Stretch:

Thoracic Spine Mobilization:

Open Books - Active Thoracic Spine Mobilization:

Rotational mobilization for thoracic spine mobilization, stabilization and strengthening:

Bibliography:

  1. Phillip Page, Clare FrankRobert LardnerAssessment and Treatment of Muscle Imbalance: The Janda Approach © 2010 Benchmark Physical Therapy, Inc., Clare C. Frank, and Robert Lardner
  2. Dr. Mike Clark & Scott Lucette, “NASM Essentials of Corrective Exercise Training” © 2011 Lippincott Williams & Wilkins
  3. Donald A. Neumann, “Kinesiology of the Musculoskeletal System: Foundations of Rehabilitation – 2nd Edition” © 2012 Mosby, Inc.
  4. Michael A. Clark, Scott C. Lucett, NASM Essentials of Personal Training: 4th Edition, © 2011 Lippincott Williams and Wilkins
  5. Leon Chaitow, Muscle Energy Techniques: Third Edition, © Elsevier 2007
  6. Tom Myers, Anatomy Trains: Second Edition. © Elsevier Limited 2009
  7. Shirley A Sahrmann, Diagnoses and Treatment of Movement Impairment Syndromes, © 2002 Mosby Inc.
  8. David G. Simons, Janet Travell, Lois S. Simons, Travell & Simmons’ Myofascial Pain and Dysfunction, The Trigger Point Manual, Volume 1. Upper Half of Body: Second Edition,© 1999 Williams and Wilkens
  9. Cynthia C. Norkin, D. Joyce White, Measurement of Joint Motion: A Guide to Goniometry – Third Edition. © 2003 by F.A. Davis Company
  10. Cynthia C. Norkin, Pamela K. Levangie, Joint Structure and Function: A Comprehensive Analysis: Fifth Edition © 2011 F.A. Davis Company
  11. Florence Peterson Kendall, Elizabeth Kendall McCreary, Patricia Geise Provance, Mary McIntyre Rodgers, William Anthony Romani, Muscles: Testing and Function with Posture and Pain: Fifth Edition © 2005 Lippincott Williams & Wilkins
  12. Karel Lewit. Manipulative Therapy: Musuloskeletal Medicine © 2007 Elsevier
  13. Carolyn Richardson, Paul Hodges, Julie Hides.  Therapeutic Exercise for Lumbo Pelvic Stabilization – A Motor Control Approach for the Treatment and Prevention of Low Back Pain: 2nd Edition (c) Elsevier Limited, 2004
  14. Andrew Biel, Trail Guide to the Human Body: 4th Edition, © 2010
  15. Scovazzo ML, Browne A, Pink M, et. al.: The Painful shoulder during freestyle swimming. Am J Sports Med 19(6):577-582, 1991
  16. Lawrence, R. L., Braman, J. P., Laprade, R. F., & Ludewig, P. M. (2014). Comparison of 3-dimensional shoulder complex kinematics in individuals with and without shoulder pain, part 1: sternoclavicular, acromioclavicular, and scapulothoracic joints. journal of orthopaedic & sports physical therapy, 44(9), 636-A8.
  17. Dean, N.A. and B.S. Mitchell 2002. Anatomic relation between the nuchal ligament (ligamentum nuchae) and the spinal dura mater in the craniocervical region. Clin. Anat. 15:182-185.
  18. Lind CS, et al. (2015). Quantification of trapezius muscle innervation during neck dissections: cervical plexus versus the spinal accessory nerve. Annals of Otology, Rhinology, & Laryngology. 124(11): 881-885.
  19. Canella C, Demondion X, Abreu E, et al. (2013). Anatomical study of the spinal accessory nerve using ultrasonography. European Journal of Radiology. 82:56-61.
  20. Tubbs RS, Shoja MM, Loukas M, et al. (2011). Study of the cervical plexus innervation of the trapezius muscle. J. Neurosurg Spine. 14: 626-629.
  21. Choi W, Cynn H, Lee C, et al. Shrug exercises combined with shoulder abduction improve scapular upward rotator activity and scapular alignment in subjects with scapular downward rotation impairment. Journal of Electromyography and Kinesiology. 25: 363-370.

© 2016 Brent Brookbush

Questions, comments, and criticisms are welcome and encouraged.