Trapezius Muscle: Location, Actions, and Trigger Points

Posted on 10 Nov 2010 23:24

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The trapezius is a three part (tripartite) muscle of the upper back extending from the base of the skull all the way to the lower thoracic spine and laterally from the clavicle to the entire length of the spine of the scapula. Together the two trapezii form a diamond or kite-shaped trapezoid from which the muscle derives its name.

See the The Trigger Point Therapy Workbook.

Although usually discussed as one muscle it is separated into distinct groups of fibers which run in different directions and thus can have slightly different movement roles. These different groups of fibers are usually referred to as the upper, middle, and lower trapezius. Some experts divide the middle section into two parts, the upper middle and lower middle but for the purposes of this trigger point explanation we will consider only three divisions.

In general the action of the trapezius is to elevate and depress the scapula and to rotate the shoulder girdle upward and downwards. The trapezius also extends the head and when all the fibers work together they tend to pull the shoulder upward and adduct the scapula1.

The trapezius fixes the scapula for movement of the shoulder joint and continuously rotates the scapula upward to permit the arm to be raised over the head. The trapezius is most well-known as the "shrug" muscle and it is worked heavily with the traditional bodybuilding shrug exercise as well as during the Olympic lifts and anything that elevates the shoulders. More specific functions of the upper, lower, and middle fibers will be discussed below under "actions".

trapezius muscle diagram
trapezius muscle diagram

The trapezius is sometimes considered an "upper back" muscle or a "shoulder" muscle but it is more correctly considered a muscle of the scapulothoracic joint of the shoulder girdle2. The action of the trapezius is closely linked with the levator scapulae in shoulder elevation and it's other synergists in this role are the rhomboids major and minor. Other trapezius muscle relationships are shown in the table below.

The upper trapezius was found by Travell and Simons to be the muscle most often affected by trigger points, which has been confirmed by other authors. The closely related levator scapulae was also found to be the top runner in some studies and this would make sense because the same perpetuating circumstances that affect the trapezius would also affect the levator scapulae.[1]

Trapezius Synergists and Antagonists Muscles by Shoulder Girdle Action

Elevation Depression
Trapezius (Upper Fibers) Trapezius (Lower Fibers)
Rhomboid Major Pectoralis Minor
Rhomboid Minor
Levator Scapula
Abduction (Protraction) Adduction (Retraction)
Serratus Anterior Trapezius (Middle Fibers)
Pectoralis Minor Rhomboid Major
Rhomboid Minor
Upward Rotation Downward Rotation
Trapezius (Upper &Lower Fibers) Rhomboid Major
Serratus Anterior Rhomboid Minor
Levator Scapula

Trapezius Origin, Insertion, and Actions

Origin: Upper fibers: base of skull at occipital protuberance and the nuchal ligaments (ligamentum nuchae) of neck. Middle fibers: spinous processes of seventh cervical vertebra and upper three thoracic vertebrae. Lower fibers: spinous processes of fourth through twelfth thoracic vertebrae.

The upper (superior) fibers proceed from their origin downward and laterally. The middle fibers run laterally to toward the acromion process and the lower (inferior) fibers run upward and laterally.

Insertion: Upper fibers: posterior aspect of the lateral third of the clavicle. Middle fibers: medial border of acromion process and superior lip of the posterior border of the spine of the scapula. Lower fibers: tubercle at the apex smooth triangular surface at base of scapular spine via an aponeurosis.

Action: Upper fibers: elevation and adduction of the shoulder girdle; extension of the head. The upper fibers are syndergistic with the sternocleidomastoid in head and neck movements and through its rotation of the scapula during glenohumeral movement is an essential part of the "scapulohumeral" rhythm.

Middle Fibers: elevation, upward rotation and adduction of the scapula. By helping to stabilize the scapula these fibers aid in the elevation of the arm.

Lower fibers: depression and adduction of the scapula.

Both sides of the trapezius work together during extension of the head, neck and thoracic spine and during any symmetrical lifting activity such as overhead pressing.

Trapezius Trigger Points Referred Pain, Symptoms, and Causes

There are six main trigger points of the trapezius, two in each portion of the muscle, plus one unusual one which causes only autonomic phenomena. These trigger points are numbered in the images below in order of their prevalence and will be discussed in that order. Note that the position of the trigger point has nothing to do with its number. For instance, although trigger points one and two are in the upper part of the trapezius, three and four are in the lower part, and five and six are in the middle portion.

The trigger points of the upper fibers (TrP1,2) as stated above, were found by Travel and Simons to be the most frequently identified in the body. They refer pain to the postolateral part of the neck, behind the ear and to the temple.

Trigger points can be activated in any part of the trapezius by a sudden trauma such as falling off a height, down stairs, or suffering whiplash in an automobile accident. Poor posture such as forward head posture, misfitting furniture such as arm rests that are too low, muscular abuse and prolonged immobility. They can also be caused by any number of general mechanical "perpetuating" factors:

  • skeletal asymmetry
    • lower limb length inequality
    • pelvis smaller on one side (small "hemipelvis")
  • skeletal disproportion
    • "Morton's Foot" - long second metatarsal bone
    • short upper arms

Lower leg length inequality or an uneven pelvic size tilts the shoulder girdle and overloads the upper trapezius. The pelvis is tilted laterally which causes a spinal curve, thus tiling the shoulder so that one side of the body sags. The upper trapezius has to work continuously to keep the head and neck vertical and the eyes level.

A misfitted walking cane can cause a similar problem. If the walking cane is too long it forces up the shoulder on the side of the cane which causes a shoulder tilt that must be corrected for by the trapezius. With a properly fitted walking cane the elbow will should not be bent more than 25 degrees while the shoulder remain level. When possible it is best to have walking canes fitted by a professional.3

The trapezius supports the weight of the shoulders and arms so it is always working against gravity. Normally this is well within its reach but certain behaviors or circumstances add to this load such as activities requiring the arm to be held up for long periods. Talking on the telephone for long periods can be a big problem. Today, this problem can be easily solved by a handless device. Similar to the levator scapulae, a computer keyboard that is placed too high or lots of driving with the hands at the top of the steering wheel can overload the upper fibers as the shoulders hunch up to compensate for this high arm position.

Other possibilities are backpacking with heavy packs hung from the shoulders, heavy bags or purses with shoulder straps, violin playing, and sleeping on the stomach with the head turned sharply to one side. Women with large breasts can have trouble with the trapezius and especially when wearing tightly fitted bras with narrow bra straps, in which the shoulder or the torso straps can be too tight. Most women wear improperly fitted bras without knowing it and this is a major contributor to neck, upper back, and shoulder pain. It really pays to have a professional measure and outfit you with properly fitted bras.

The middle trapezius is affected by arm being help up and in front for long periods. Any activity that increases tension in the pectoralis major and pulls the scapula and shoulders forward, resulting in a round-shouldered posture, overload the middle trapezius and rhomboids. Strength training with too much bench pressing or too much emphasis on internal shoulder rotator dominant movements may lead to a tight pectoralis and so bring on trapezius strain and trigger points.

Similar to the upper fibers, driving with the hands at the top of the steering wheel can strain these fibers cine the shoulders round forward.

The lower fibers are strained by any activity that requires bending and reaching for long periods of time. May occupations may fit this scenario.

Of course, as many people realize, the trapezius suffers when we are chronically stressed or anxious. We tend to hunch up the shoulders and hold tension in the shoulders and neck, which puts constant strain on the trapezius. Like the levator scapulae the trapezius is also affected by chronic "high chest" breathing which can accompany anxiety and stressful periods but lead to a chronic problem on its own. Read more about breathing and relaxation and how you can get control of this problem.

Trapezius Upper Trigger Points Number One and Two

TrP1, located at the very top of the trapezius, when intense enough, refers pain unilaterally from postolateral aspect of the neck4 to the mastoid process and upwards along the side of the head to the temple where the pain concentrates. As you can see in the TrP1 image below the main areas of pain are the side of the neck, the mastoid process or corner of the jaw, and the temple region with spillover pain being felt from the neck to the jaw and in an arch from the neck to the temple and back of the eye socket, forming a question mark shape. In general this trigger point causes sever pain on the side of the neck toward the back and a temporal headache. This trigger point is consistently associated with myogenic or "tension" headache.5


upper trapezius trigger point number 1 with referred pain patterns

Upper Trapezius Trigger Point 1 (TrP1)

upper trapezius trigger point number 1 with referred pain patterns

Upper Trapezius Trigger Point 1 (TrP1)

Trigger points in the upper trapezius, the temporalis, suboccipital muscles, and sternocleidomastoid are consistently found to be a clinical feature of both chronic and episodic tension type headaches. Trigger points in the levator scapulae, masseter and splenius captitus or cervicus may be associated as well.

Sometimes pain is referred from TrP1 all the way in the back of the head at the occipital protuberance6. Also, pain is occasionally referred to the lower molar teeth and to the pinna (outer part of the ear) but deep ear pain is not a feature of this TrP. Satellite trigger points may be induced in some of the muscles of mastication or the temple leading to jaw and face pain or any of the symptoms associated with trigger points in these muscles. Satellite TrP's in the scalenes may send pain down the arms and the rhomboids and supraspinatus of the same side are also a potential site of satellites as well as any of the muscles mentioned above. Of course, trigger points in the contralateral trapezius are possible as well but most lay people may have a hard time differentiating between a "satellite" trapezius caused by trigger points in the opposite trapezius from any other trigger point of the trapezius. Most people would do well to treat both sides equally unless evaluated by a professional.

Dizziness or "vertigo" has sometimes been associated with this TrP but this may be related to trigger points in the clavicular branch of the sternocleidomastoid which is a synergist of the upper trapezius and could be stimulated by activity in upper trapezius trigger points via a reflex stimulation.

Trapezius trigger point one is located in the middle part of the front of the upper trapezius. These fibers are almost vertical and are right where the muscle joins the neck. Pinch the roll of muscle at the very top of this area to find the trigger point.

Trapezius TrP2 is more to the side, and a bit further back and deeper than TrP1, located in the more horizontal fibers of the upper trapezius atop the shoulders. Its referred pain pattern is similar to TrP1 but a bit more posterior with the pain more toward the back of the neck. The pain pattern blends with TrP1 behind the ear. A sore neck may be associated with trigger points in this area but a headache is generally not associated with it.

The image below shows the approximate area where this trigger point may occur, as is true of trigger points three and four in the same . Do not be confused by the area at the bottom of the trapezius labelled T12, which conveys the lowest insertion point of the lower trapezius fibers, the T-12 spinous process of the thoracic spine. Notice that the trigger points are labeled "TrP" not just "T".

trapezius muscle trigger point drawing with referred pain patterns

Trapezius Trigger Points 2 through 7

trapezius muscle trigger point drawing with referred pain patterns

Trapezius Trigger Points 2 through 7

General symptoms of trigger points in the upper fibers include may cause pain when turning the neck all the way to the opposite side of the active trigger points. Although upper trapezius trigger points are claimed to cause a 'stiff neck', according to Travell and Simons an acute and painful stick neck would involve accompanying trigger points in the levator scapulae and perhaps the spenius cervicis muscles and this would severely limit rotation of the head to the same side. An intolerance to weight on the shoulders such as from heavy overcoats may also develop.

Trapezius Lower Trigger Points Number Three and Four

Trigger point three of the lower trapezius is very common. Since it has a tenancy to cause a pain and deep tenderness to the upper trapezius region you may mistake this for upper trapezius trigger points. However, satellite trigger points do not usually occur in the upper trapezius as a result of TrP3. Be aware of the difference between this difuse pain and tenderness and the local tenderness and taut bands of the trigger points, which when pressed are very tender and sensitive and may trigger pain to their signature referred pain regions. TrP3 may, however, induce other satellite trigger points in the upper back and neck muscles and can be the cause of consistent upper back and neck pain after the upper trapezius trigger points have been treated.

TrP3 is located in the lower trapezius near the middle fibers of the lower trapezius usually near the lower border of the muscle. Besides the pain and tenderness mentioned above it refers pain staring in the paraspinal region adjacent to it and extending up to the cervical paraspinal area7, over the top of the scapula, and to the mastoid area behind the ear of the same side, as well as to the acromion at the top of the shoulder, which is the bony joint at the top of the shoulder that most people associate with the shoulder itself, as opposed to the actual shoulder joint.8

Trigger point 4 of the lower trapezius (not the middle as reported by Davies9) is probably an attachment trigger point and is located next to the inner border of the scapula. It refers pain primarily to the area bordering the scapula on the same side.

Trapezius Middle Trigger Points Number Five, Six, and Seven

TrP5 is located close to the upper part of the inner border of the scapula. It causes interscapular pain which will be felt as a burning pain between the scapula and the spine, which occurs between the TrP and the spinous processes of C7 and T1 (see the location of C7 in the image ).

TrP6 is probably an attachment trigger point and is found close to the top of the shoulder in the middle trapezius close to where the muscle inserts to the acromion process and the superior lip of the of the spine of the scapula. It causes localized pain and tenderness over the acromion, similar to some of the referred pain from TrP3. This trigger point can make it difficult to carry a heavy purse or bag with a shoulder strap or to tolerate the weight of a heavy coat.

TrP7 is located close to the area of TrP5 but is very rarely found. It causes autonomic phenomena such as goosebumps on the side of the arm and sometimes on the thigh as well as a weird feeling "like shivers running up and down the spine" such as one feels in response to fingernails being scraped across a blackboard.

Trapezius Trigger Point self Treatment

Trp1 is easily kneaded by the fingers. It is located just under the skin so can be easily pinched between the fingers and thumb. It should feel like a firm strand or cord of muscle that can be as small as a pencil lead or as big as the pencil itself. Squeezing it between the thumb and finders firmly may reproduce the referred pain pattern and bring on a temple headache. This will verify the trigger point as the cause of the pain. Some with a very well developed upper trapezius, a very tight upper trapezius, or a lot of extra fat in the region may have some trouble locating it. Relaxing the arm on the side you're working on may help. Put your hand in your pocket or support the arm on a cushion held on the lap. Remember, this is an extremely common trigger point, maybe the most common. If you have any neck or head pain you probably have this one.

Davies recommends pressing the trigger point between a tennis ball and the thumb if the hand gets to fatigued. Put a tennis ball against a wall and press the back of you upper trapezius against it. Then wedge the trigger point between the ball and your thumb, pressing and massaging.

All of the other trigger points can be treated with the Thera Cane self massager. Use the knob on the crook end of the cane in contact with the trigger point and massage. A ball against the wall will also work well for all the points except for TrP (ball method for TrP1 described above) which is a bit high to use a ball on. A tennis ball can be used if the points are very tender. A firmer massage ball or lacrosse ball can be used to go deeper. And small bouncy rubber balls (which are very firm) can be used for fine precision. Bouncy balls are easy to find at party stores as they are often used as party favors for children's birthday parties. You may even be able to find a pack of assorted sizes from small to very small. They make great massage tools. See Davies, Pages 58-60 for more detailed instructions.

This "Trapezius Muscle: Location, Actions, and Trigger Points" page is provided by Ground Up Strength for information purposes only and should not take the place of professional medical advice. Although we have done our utmost to provide accurate and safe information, we are not medical professionals and the information on this page should not be taken as professional medical advice, or any other kind of medical advice. Any self-treatment undertaken by you is undertaken at your own risk.

1. Simons, David G., Janet G. Travell, Lois S. Simons, and Janet G. Travell. "Chp. 8: Masseter Muscle." Travell & Simons' Myofascial Pain and Dysfunction: the Trigger Point Manual. Baltimore: Williams & Wilkins, 1999. 329. Print.
2. Davies, Clair. The Trigger Point Therapy Workbook: Your Self-treatment Guide for Pain Relief. Oakland, CA: New Harbinger Publications, 2004. Print.
3. Behnke, Robert S. Kinetic Anatomy. Champaign, IL: Human Kinetics, 2001. Print.
4. Floyd, R. T., and Clem W. Thompson. Manual of Structural Kinesiology. Dubuque, IA: WCB/McGraw-Hill, 1998. Print.
5. De Las Penas, Cesar F., Lars Arendt-Nielsen, and Robert Gerwin. "Chapter 6: Muscle Trigger Points in Tension Type Headache." Tension-type and Cervicogenic Headache: Pathophysiology, Diagnosis, and Management. Sudbury, MA: Jones and Bartlett, 2010. 70-71. Print.
6. Dommerholt, Jan, and Peter Huijbregts. "Chapter 6: Contributions of Myofascial Trigger Points." Myofascial Trigger Points: Pathophysiology and Evidence-informed Diagnosis and Management. Sudbury, MA: Jones and Bartlett, 2011. Print.
7. Wright, A., T. Graven-Nielsen, I. I. Davies, and L. Arendt-Nielsen. "Temporal Summation of Pain from Skin, Muscle and Joint following Nociceptive Ultrasonic Stimulation in Humans." Experimental Brain Research 144.4 (2002): 475-82. Print.

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This page created 10 Nov 2010 23:24
Last updated 30 Jul 2017 22:52

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