请输入您要查询的百科知识:

 

词条 Trapezius
释义

  1. Structure

     Nerve supply 

  2. Function

     Scapular movements  Spinal movements 

  3. Society and culture

     Exercises 

  4. Symptomatology

      Tensions  

  5. References

  6. External links

{{Use American English|date = January 2019}}{{Short description|Muscle between the lower spine and the shoulder blade}}{{Use mdy dates|date = January 2019}}{{Infobox muscle
| Name = Trapezius
| Latin = Musculus trapezius
| Image = Trapezius.png
| Caption = The trapezius muscle is a surface muscle of back, shown in red above and below
| Image2 = Trapezius Gray409.PNG
| Origin =external occipital protuberance, spinous processes of vertebrae C7-T12, Nuchal ligament, Occipital Bone[1]

Medial one-third of superior nuchal line

External occipital protuberance

Ligamentum nuchae

T1-T12 spine

Corresponding supraspinous ligaments


| Insertion = nuchal ligament, medial superior nuchal line, posterior border of the lateral one-third of the clavicle, acromion process, and spine of scapula
| Blood = superficial branch of transverse cervical artery or superficial cervical artery[2]
| Nerve = accessory nerve (motor)
cervical spinal nerves C3 and C4 (motor and sensation)[3]| Action = Rotation, retraction, elevation, and depression of scapula
| Antagonist = serratus anterior muscle, Latissimus dorsi, Great chest muscle
}}

The trapezius (or trapezoid)[4] is a large paired surface muscle that extends longitudinally from the occipital bone to the lower thoracic vertebrae of the spine and laterally to the spine of the scapula. It moves the scapula and supports the arm.

The trapezius has three functional parts: an upper (descending) part which supports the weight of the arm; a middle region (transverse), which retracts the scapula; and a lower (ascending) part which medially rotates and depresses the scapula. The trapezius is used to nod your head. It is also used to hold up your head.

Structure

The trapezius muscle resembles a trapezium (trapezoid in American English), or diamond-shaped quadrilateral. The word "spinotrapezius" refers to the human trapezius, although it is not commonly used in modern texts. In other mammals, it refers to a portion of the analogous muscle. Similarly, the term "tri-axle back plate" was historically used to describe the trapezius muscle.{{citation needed|date=September 2018}}

The superior or upper (or descending) fibers of the trapezius originate from the spinous process of C7, the external occipital protuberance, the medial third of the superior nuchal line of the occipital bone (both in the back of the head), and the ligamentum nuchae. From this origin they proceed downward and laterally to be inserted into the posterior border of the lateral third of the clavicle.

The middle fibers, or transverse of the trapezius arise from the spinous process of the seventh cervical (both in the back of the neck), and the spinous processes of the first, second, and third thoracic vertebrae. They are inserted into the medial margin of the acromion, and into the superior lip of the posterior border of the spine of the scapula.

The inferior or lower (or ascending) fibers of the trapezius arise from the spinous processes of the remaining thoracic vertebrae (T4–T12). From this origin they proceed upward and laterally to converge near the scapula and end in an aponeurosis, which glides over the smooth triangular surface on the medial end of the spine, to be inserted into a tubercle at the apex of this smooth triangular surface.

At its occipital origin, the trapezius is connected to the bone by a thin fibrous lamina, firmly adherent to the skin. The superficial and deep epimysia are continuous with an investing deep fascia that encircles the neck and also contains both sternocleidomastoid muscles.

At the middle, the muscle is connected to the spinous processes by a broad semi-elliptical aponeurosis, which reaches from the sixth cervical to the third thoracic vertebræ and forms, with that of the opposite muscle, a tendinous ellipse. The rest of the muscle arises by numerous short tendinous fibers.

It is possible to feel the muscles of the superior trapezius become active by holding a weight in one hand in front of the body and, with the other hand, touching the area between the shoulder and the neck.{{citation needed|date=October 2017}}

Nerve supply

Motor function is supplied by the accessory nerve. Sensation, including pain and the sense of joint position (proprioception), travel via the ventral rami of the third (C3) and fourth (C4) cervical nerves. Since it is a muscle of the upper limb, the trapezius is not innervated by dorsal rami despite being placed superficially in the back.

Function

Contraction of the trapezius muscle can have two effects: movement of the scapulae when the spinal origins are stable, and movement of the spine when the scapulae are stable.

Its main function is to stabilize and move the scapula.

Scapular movements

The upper and lower fibers tend to rotate the scapula around the Sternoclavicular articulation so that the acromion and inferior angles move up and the medial border moves down. This rotation is in the opposite direction to that produced by levator scapulae and the rhomboids.

The middle fibers retract the scapula.

The upper and lower trapezius fibers also work in tandem with the serratus anterior to upwardly rotate the scapulae, such as during an overhead press. When activating together, the upper and lower fibers also assist the middle fibers (along with other muscles such as the rhomboids) with scapular retraction/adduction.

Spinal movements

When the scapulae are stable a co-contraction of both sides can extend the neck.

Society and culture

Exercises

  • The upper portion of the trapezius can be developed by elevating the shoulders. Common exercises for this movement are any version of the clean, particularly the hang clean.
  • Middle fibers are developed by pulling shoulder blades together. This adduction also uses the upper/lower fibers.
  • The lower part can be developed by drawing the shoulder blades downward while keeping the arms almost straight and stiff.

It is mainly used in throwing, with the deltoid muscle and rotator cuff.

Many bodybuilders, including eight-time Mr. Olympia winner Ronnie Coleman, perform a maneuver known as a 'trap slap' (short for trapezius slap) before attempting to lift particularly heavy weights.[5] This technique involves a spotter slapping the lifter's upper back, with the desired effect of mentally preparing the recipient for their upcoming lift.[6] Variants of the trap slap include the 'lat slap' (short for latissimus dorsi slap), performed if the trapezius is inaccessible to the spotter (i.e. during a back squat).

Symptomatology

Tensions

Due to not being healthily developed for some people, it can easily cause problems such as muscular tensions, especially the descending part. In severe cases these might cause a cervical spine syndrome.[7]

References

{{Gray's}}
1. ^https://books.google.com/books?id=7ca8iqAPo2UC&pg=PA54
2. ^{{cite web |url=http://iris3.med.tufts.edu/headneck/Triangles/Posterior%20Triangle%20of%20the%20Neck.htm |title=Tufts |accessdate=2007-12-11 |work= |deadurl=yes |archiveurl=https://archive.is/20030422234442/http://iris3.med.tufts.edu/headneck/Triangles/Posterior%20Triangle%20of%20the%20Neck.htm |archivedate=2003-04-22 |df= }}
3. ^{{cite book|last=Arthur F. Dalley|first=Keith L. Moore, Anne M.R. Agur|title=Clinically oriented anatomy|year=2010|publisher=Lippincott Williams & Wilkins, Wolters Kluwer|location=Philadelphia [etc.]|isbn=978-1-60547-652-0|pages=700|edition=6th [International]}}
4. ^https://books.google.com/books?id=K7zUXnad7jIC&pg=PA89&dq=%2B"trapezoid"
5. ^https://www.youtube.com/watch?v=LVVdlwf1iyM
6. ^https://www.youtube.com/watch?v=4-Va6GdGHBw
7. ^{{Cite web|url=http://flexikon.doccheck.com/en/Cervical_spine_syndrome|title=Cervical spine syndrome - DocCheck Flexikon|last=GmbH|first=DocCheck Medical Services|website=DocCheck Flexikon|language=en|access-date=2017-11-09}}

External links

{{Commons category|Trapezius muscle}}
  • {{Exrx|Muscles/TrapeziusUpper}}
  • Superficial Back Dissection Video showing trapezius
{{Muscles of thorax and back}}{{Portal bar|Anatomy}}{{Authority control}}

2 : Back anatomy|Muscles of the upper limb

随便看

 

开放百科全书收录14589846条英语、德语、日语等多语种百科知识,基本涵盖了大多数领域的百科知识,是一部内容自由、开放的电子版国际百科全书。

 

Copyright © 2023 OENC.NET All Rights Reserved
京ICP备2021023879号 更新时间:2024/9/22 7:11:01