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== Description ==
== Description ==
The pectoralis minor is located under the pectoralis major, and both form the anterior wall of the axilla. The shortened , tight muscle can be easily palpated there. It is also located close in relation to the brachial plexus and both the subclavian artery and vein, which all run between the muscle and the rib cage. Pectorlis minor and coracoid process together form a bridge under which nerves and vessels go to he upper limb .kenhub.Pectoralis minor muscle. Available from:https://www.kenhub.com/en/library/anatomy/pectoralis-minor-muscle (accessed 20 July 2018).Keith L. , Anne M. R . Clinically Oriented Anatomy seventh edition . philidephia : Lippincott Williams & Wilkins.Feb 13, 2013
The pectoralis minoris triangular in shape andis located under the pectoralis major, and both form the anterior wall of the axilla. The shortened , tight muscle can be easily palpated there. It is also located close in relation to the brachial plexus and both the subclavian artery and vein, which all run between the muscle and the rib cage. Pectorlis minor and coracoid process together form a bridge under which nerves and vessels go to he upper limb .kenhub.Pectoralis minor muscle. Available from:https://www.kenhub.com/en/library/anatomy/pectoralis-minor-muscle (accessed 20 July 2018).Keith L. , Anne M. R . Clinically Oriented Anatomy seventh edition . philidephia : Lippincott Williams & Wilkins.Feb 13, 2013


== Anatomy ==
== Anatomy ==


=== Origin ===
=== Origin ===
Pectoralisminoris a triangular in shape it`s base arisesis formedby fleshy slipsarisefrom the anteriorofthird to fifth ribsnear theircostalcartilages variationsin the origin of the muscle is common.
The base of pectoralisminor is formed by fleshy slipsarisingfrom the anterior third to fifth ribs, close to thecostalcartilage. Variationsin the origin of the muscle is common.


=== Insertion ===
=== Insertion ===
The apex of the triangleis insertedinto the medial border and upper surface of coracoid process of the scapula.
The apex of the triangleinsertsinto the medial border and upper surface of coracoid process of the scapula.


=== Nervesupply===
=== NerveSupply===
It'smain nerve supply isbythe medial pectoral nerves (C8_T1),itmay alsoreceive fromthe lateral pectoral nerve via a communicating branch known asthe''''ansa pectoralis'''',
Itsmain nerve supply isfromthe medial pectoral nerves (C8_T1),Itmay alsobe innervated bythe lateral pectoral nerve via a communicating branch known as ''''ansa pectoralis'''',


=== Arterysupply===
=== ArterySupply===
本机可血l that supplies the pectoralis minor musclewith bloodis the thoracoacromial artery, which isa short artery that branches off the larger axillary artery of the chest and upper extremities.Study.com. Pectoralis Minor: Function, Blood Supply & Innervation.Avilablefrom:https://study.com/academy/lesson/pectoralis-minor-function-blood-supply-innervation.html (accessed 20 July 2018).
本机可血l that supplies the pectoralis minor muscleis the thoracoacromial artery;a short artery that branches offfromthe larger axillary artery of the chest and upper extremities.Study.com. Pectoralis Minor: Function, Blood Supply & Innervation.Availablefrom:https://study.com/academy/lesson/pectoralis-minor-function-blood-supply-innervation.html (accessed 20 July 2018).


=== Function ===
=== Function ===
* The primary actions of this muscle include the stabilization, depression, abduction or protraction, internal rotation and downward rotation of the scapula.
* The primary actions of this muscle include the stabilization, depression, abduction or protraction, internal rotation and downward rotation of the scapula.
* It elevates the ribs for deep inspiration when the pectoral girdle is fixed or elevated.
* It elevates the ribs for deep inspiration when the pectoral girdle is fixed or elevated.
* With the scapula stabilized in a position of good alignment, the pectoralis minor acts as an accessory muscle of inspiration. Kendall F, McCreary E, Provance P,Rodgers M,Romani W. Muscles:Testing and function with posture and pain. 5th ed. Philadelphia: Lippincott Williams & Wilkins, 2005.
* With the scapula stabilized,in a position of good alignment, the pectoralis minor acts as an accessory muscle of inspiration. Kendall F, McCreary E, Provance P,Rodgers M,Romani W. Muscles:Testing and function with posture and pain. 5th ed. Philadelphia: Lippincott Williams & Wilkins, 2005.
* When the ribs are immobilized, this muscle brings the scapula forward,
* When the ribs are immobilized, this muscle brings the scapula forward,
* Both pectoralis muscles work with the serratus anterior muscles to createafull range of movement for the scapula.health line. Pectoralis minor. Available from: https://www.healthline.com/human-body-maps/pectoralis-minor#1 \(accessed 20 July).
* Both pectoralis muscles work with the serratus anterior muscles to create full range of movement for the scapula.health line. Pectoralis minor. Available from: https://www.healthline.com/human-body-maps/pectoralis-minor#1 \(accessed 20 July).


== Clinicalrelevance==
== ClinicalRelevance==


=== Weakness ===
=== Weakness ===
When pectoralis minor is weak, the strength of arm is diminished. Moreover, weakness of this muscle will increase respiratory difficulty in patients alreadysuffering involvementof the respiratory muscles.
When pectoralis minor is weak, the strength of arm is diminished. Moreover, weakness of this muscle will increase respiratory difficulty in patients alreadyexperience fatigue and/or compromiseof the respiratory muscles.


===Shortness===
===Shortnening===
*As mentioned by vladmir janda`s,Pectoralis minorisone oftonicmusclesthat tends to be overactive,prone tobe tight in our body.Page .P, Frank C, Lardner R. Assessment and Treatment of Muscle Imbalance: The Janda Approach .Champaign . Human Kinetics. 2010.
* Pectoralis minor isatonicmusclethat tends to be overactiveandprone totightness.Page .P, Frank C, Lardner R. Assessment and Treatment of Muscle Imbalance: The Janda Approach .Champaign . Human Kinetics. 2010.
* In Neurokinetic therapy (NKT),pctoralis mnoris consideredTheking of compensation, as it tends to be overactive for an inhibited or under active [[Serratus Anterior|Serratus anterior]],it's easilytobeshortened and tightbecause of many factors, including rounded shoulder posture, glenohumeral joint dysfunction,breathing dysfunction, anda variety of compensation.Neurokinetic Therapy® The Missing Link.The Pectoralis Minor, King of Compensation. Available from:https://neurokinetictherapy.com/the-pectoralis-minor-king-of-compensation?fbclid=IwAR34776TwROAI2UYWziqwf0EO2kF4tngWEGqiSaF81AHBRpv_AYlb5u6LDI (accessed 12/4/2019)
* In Neurokinetic therapy (NKT),pectoralis minoris consideredtheking of compensation, as it tends to be overactive for an inhibited or under active [[Serratus Anterior|Serratus anterior]]. There are many factors that causeit tobecomeshortened and tight, including rounded shoulder posture, glenohumeral joint dysfunction,breathing dysfunction, andother compensatory factors.Neurokinetic Therapy® The Missing Link.The Pectoralis Minor, King of Compensation. Available from:https://neurokinetictherapy.com/the-pectoralis-minor-king-of-compensation?fbclid=IwAR34776TwROAI2UYWziqwf0EO2kF4tngWEGqiSaF81AHBRpv_AYlb5u6LDI (accessed 12/4/2019)
*Over activepectoralisminaorandunder activeserratus anterior leads to prominence of medial border of the scapula,anterior tilting of thescapula makinginferior angle ofthe scapula prominent.and depressthe coracoid processof the scapula both forward and downward.Suchmuscle shortening is an important contributing factor in many cases of arm pain
*An overactivepectoralisminorandunderactiveserratus anterior leads towinging of the scapula -prominence ofthemedial border of the scapulawithanterior tilting, together with prominenceof the inferior angleand depressionof the coracoid process.Thismuscle shortening is an important contributing factor in many cases of arm pain.
* With the cords of brachial plexus and the axillary blood vessels lying between the coracoid process and the rib cage, shortening of pectoralis minor may produce impingement on these large vessels and nerves, causing shoulder impingement and thoracic outlet syndrome.
* With the cords of brachial plexus and the axillary blood vessels lying between the coracoid process and the rib cage, shortening of pectoralis minor may produce impingement on these large vessels and nerves, causing shoulder impingement and thoracic outlet syndrome.
* A shortened pectoralis minor restricts flexion of the shoulder joint by limiting scapular rotation and preventing glenoid cavity from attaining the cranial orientation necessary for complete flexion of the joint.
* A shortened pectoralis minor restricts flexion of the shoulder joint by limiting scapular rotation and preventing glenoid cavity from attaining the cranial orientation necessary for complete flexion of the joint.
'''N.B''' if you want to activatessrratusanterior andminmizethe work or activity of Pectoralis minor you have to do exercises that has highly selective activation for serratus anterior not pectoralis minorand theseexercises are :Castelein, B., Cagnie, B., Parlevliet, T., Cools, A. [https://www.sciencedirect.com/science/article/abs/pii/S1356689X15002520?via%3Dihub Serratus anterior or pectoralis minor: Which muscle has the upper hand during protraction exercises?.] Manual Therapy,April 2016: 22, 158–164.
'''N.B''' if you want to activateserratusanterior andminimizethe work or activity of Pectoralis minor you have to do exercises that has highly selective activation for serratus anterior not pectoralis minorthe most effectiveexercises are :Castelein, B., Cagnie, B., Parlevliet, T., Cools, A. [https://www.sciencedirect.com/science/article/abs/pii/S1356689X15002520?via%3Dihub Serratus anterior or pectoralis minor: Which muscle has the upper hand during protraction exercises?.] Manual Therapy,April 2016: 22, 158–164.
* Serratus Punchexercise: it`shighly selective to serratus anterior.
* Serratus PunchExercise: itishighly selective to serratus anterior.
*heModified Push-Up Plusexercises,bothinfloor and wall version, withonly focusingon the concentric phase ofheexercise.
*TheModified Push-Up PlusExercise:bothon thefloor andand against thewall version, withemphasison the concentric phase oftheexercise.
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=== Trigger points ===
=== Trigger points ===
在胸小肌触发点几乎identical referred pain patterns as in pectoralis major muscle.These pain patterns start in the front of shoulder and can extend down the inside of the arm, elbow, forearm, palm of the hand, and into the pinky, ring, and middle fingers. A tense pectoralis minor muscle can also entrap nerves in the armpit regionthat causepain, numbness, and tinglingto traveldown the arm and into the hand.trigger point therapist. Pectoralis minor. Available from:http://www.triggerpointtherapist.com/?s=pectoralis+minor (accessed 19 July 2018).
在胸小肌触发点几乎identical referred pain patterns as in pectoralis major muscle.These pain patterns start in the front of shoulder and can extend down the inside of the arm, elbow, forearm, palm of the hand, and into the pinky, ring, and middle fingers. A tense pectoralis minor muscle can also entrap nerves in the armpit regioncausingpain, numbness, and tingling down the arm and into the hand.trigger point therapist. Pectoralis minor. Available from:http://www.triggerpointtherapist.com/?s=pectoralis+minor (accessed 19 July 2018).


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=== Power ===
=== Power ===
Position: Supine. Fixation is not necessary by the examiner unless abdominal muscles are weak, in which case the rib cage on the same side should be held down firmly. Test: Forward thrust of the shoulder, with the arm at the side. Pressure: Against the anterior aspect of the shoulder, downward toward the table.
Position: Supine. Fixation is not necessary by the examiner unless abdominal muscles are weak, in which case the rib cage on the same side should be held down firmly.
测试:向前的推力,肩膀,手臂at the side. Pressure: Against the anterior aspect of the shoulder, downward toward the table.


=== Length ===
=== Length ===
Position: Patient is supine with the arms at the sides, elbows extended, palms upward, knees bent and lower back flat on the table. Test: The examiner stands at the head of the table and observes the position of the shoulder girdle. The amount of tightness is measured by the extent to which the shoulder is raised from the table and by the amount of resistance to downward pressure on the shoulder. Tightness may be recorded as slight, moderate, or marked.
Position: Patient is supine with the arms at the sides, elbows extended, palms upward, knees bent and lower back flat on the table.
Test: The examiner stands at the head of the table and observes the position of the shoulder girdle. The amount of tightness is measured by the extent to which the shoulder is raised from the table and by the amount of resistance to downward pressure on the shoulder. Tightness may be recorded as slight, moderate, or marked.


== Treatment ==
== Treatment ==
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=== Manualtherapy===
=== ManualTherapy===
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==Sealso==
==Seealso==


*[[Pectoralis major|Pectoralis major]]
*[[Pectoralis major|Pectoralis major]]
*[[Muscles of Respiration|Muscles of Respiration]]
*[[Muscles of Respiration|Muscles of Respiration]]
*[[长翅膀的肩胛骨|有翼的肩胛骨]]
*[[长翅膀的肩胛骨|有翼的肩胛骨]]
==References==
==Resources==


Revision as of 00:17, 9 August 2019

Original Editor-Esraa Mohamed Abdullzaher

Top Contributors-Ilona Malkauskaite,Lucinda hampton,Esraa Mohamed Abdullzaher,Joao Costa,Ahmed NasrandKim Jackson

Pectoralis minor.png

Description[edit|edit source]

The pectoralis minor is triangular in shape and is located under the pectoralis major, and both form the anterior wall of the axilla. The shortened , tight muscle can be easily palpated there. It is also located close in relation to the brachial plexus and both the subclavian artery and vein, which all run between the muscle and the rib cage. Pectorlis minor and coracoid process together form a bridge under which nerves and vessels go to he upper limb .[1][2]

Anatomy[edit|edit source]

Origin[edit|edit source]

The base of pectoralis minor is formed by fleshy slips arising from the anterior third to fifth ribs, close to the costal cartilage. Variations in the origin of the muscle is common.[1][2]

Insertion[edit|edit source]

The apex of the triangle inserts into the medial border and upper surface of coracoid process of the scapula.[1][2]

Nerve Supply[edit|edit source]

Its main nerve supply is from the medial pectoral nerves ( C8 _ T1 ), It may also be innervated by the lateral pectoral nerve via a communicating branch known as 'ansa pectoralis',[1]

Artery Supply[edit|edit source]

本机可血l that supplies the pectoralis minor muscle is the thoracoacromial artery; a short artery that branches off from the larger axillary artery of the chest and upper extremities.[3]

Function[edit|edit source]

  • The primary actions of this muscle include the stabilization, depression, abduction or protraction, internal rotation and downward rotation of the scapula.
  • It elevates the ribs for deep inspiration when the pectoral girdle is fixed or elevated.
  • With the scapula stabilized, in a position of good alignment, the pectoralis minor acts as an accessory muscle of inspiration.[4]
  • When the ribs are immobilized, this muscle brings the scapula forward,
  • Both pectoralis muscles work with the serratus anterior muscles to create full range of movement for the scapula.[5]

Clinical Relevance[edit|edit source]

Weakness[edit|edit source]

When pectoralis minor is weak, the strength of arm is diminished. Moreover, weakness of this muscle will increase respiratory difficulty in patients already experience fatigue and/or compromise of the respiratory muscles.[4]

Shortnening[edit|edit source]

  • Pectoralis minor is a tonic muscle that tends to be overactive and prone to tightness.[6]
  • In Neurokinetic therapy (NKT), pectoralis minor is considered the king of compensation, as it tends to be overactive for an inhibited or under activeSerratus anterior. There are many factors that cause it to become shortened and tight, including rounded shoulder posture, glenohumeral joint dysfunction,breathing dysfunction, and other compensatory factors.[7]
  • An overactive pectoralis minor and underactive serratus anterior leads to winging of the scapula - prominence of the medial border of the scapula with anterior tilting, together with prominence of the inferior angle and depression of the coracoid process. This muscle shortening is an important contributing factor in many cases of arm pain.
  • With the cords of brachial plexus and the axillary blood vessels lying between the coracoid process and the rib cage, shortening of pectoralis minor may produce impingement on these large vessels and nerves, causing shoulder impingement and thoracic outlet syndrome.
  • A shortened pectoralis minor restricts flexion of the shoulder joint by limiting scapular rotation and preventing glenoid cavity from attaining the cranial orientation necessary for complete flexion of the joint.[4]

N.Bif you want to activate serratus anterior and minimize the work or activity of Pectoralis minor you have to do exercises that has highly selective activation for serratus anterior not pectoralis minor the most effective exercises are :[8]

  • Serratus Punch Exercise : it is highly selective to serratus anterior.
  • The Modified Push-Up Plus Exercise: both on the floor and and against the wall version, with emphasis on the concentric phase of the exercise.

Trigger points[edit|edit source]

在胸小肌触发点几乎identical referred pain patterns as in pectoralis major muscle.These pain patterns start in the front of shoulder and can extend down the inside of the arm, elbow, forearm, palm of the hand, and into the pinky, ring, and middle fingers. A tense pectoralis minor muscle can also entrap nerves in the armpit region causing pain, numbness, and tingling down the arm and into the hand.[9]

Assessment[edit|edit source]

Palpation[edit|edit source]

Power[edit|edit source]

Position: Supine. Fixation is not necessary by the examiner unless abdominal muscles are weak, in which case the rib cage on the same side should be held down firmly.

测试:向前的推力,肩膀,手臂at the side. Pressure: Against the anterior aspect of the shoulder, downward toward the table.[4]

Length[edit|edit source]

Position: Patient is supine with the arms at the sides, elbows extended, palms upward, knees bent and lower back flat on the table.

Test: The examiner stands at the head of the table and observes the position of the shoulder girdle. The amount of tightness is measured by the extent to which the shoulder is raised from the table and by the amount of resistance to downward pressure on the shoulder. Tightness may be recorded as slight, moderate, or marked.

Treatment[edit|edit source]

Strengthening[edit|edit source]

Stretching[edit|edit source]


Manual Therapy[edit|edit source]


See also[edit|edit source]

References[edit|edit source]

  1. ↑1.01.11.21.3kenhub.Pectoralis minor muscle. Available from:https://www.kenhub.com/en/library/anatomy/pectoralis-minor-muscle(accessed 20 July 2018).
  2. ↑2.02.12.2Keith L. , Anne M. R . Clinically Oriented Anatomy seventh edition . philidephia : Lippincott Williams & Wilkins.Feb 13, 2013
  3. ↑Study.com. Pectoralis Minor: Function, Blood Supply & Innervation. Available from:https://study.com/academy/lesson/pectoralis-minor-function-blood-supply-innervation.html(accessed 20 July 2018).
  4. ↑4.04.14.24.3Kendall F, McCreary E, Provance P,Rodgers M,Romani W. Muscles:Testing and function with posture and pain. 5th ed. Philadelphia: Lippincott Williams & Wilkins, 2005.
  5. ↑health line. Pectoralis minor. Available from:https://www.healthline.com/human-body-maps/pectoralis-minor#1\(accessed 20 July).
  6. ↑Page .P, Frank C, Lardner R. Assessment and Treatment of Muscle Imbalance: The Janda Approach .Champaign . Human Kinetics. 2010.
  7. ↑Neurokinetic Therapy® The Missing Link.The Pectoralis Minor, King of Compensation. Available from:https://neurokinetictherapy.com/the-pectoralis-minor-king-of-compensation?fbclid=IwAR34776TwROAI2UYWziqwf0EO2kF4tngWEGqiSaF81AHBRpv_AYlb5u6LDI(accessed 12/4/2019)
  8. ↑Castelein, B., Cagnie, B., Parlevliet, T., Cools, A.Serratus anterior or pectoralis minor: Which muscle has the upper hand during protraction exercises?.Manual Therapy,April 2016: 22, 158–164.
  9. ↑trigger point therapist. Pectoralis minor. Available from:http://www.triggerpointtherapist.com/?s=pectoralis+minor(accessed 19 July 2018).
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