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Muscles: Teres Minor.

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Anatomy & Physiology: Muscles—Teres Minor.

Structure.

  • Origin: inferior lateral border of scapula.
  • Insertion: greater tubercle of humerus.

Function.

  • Concentric action: shoulder external/lateral rotation, horizontal extension, and adduction.
  • Reverse mover action: lateral tilt of scapula. Upward rotation of scapula.
  • Eccentric action: controls/restrains/slows shoulder internal rotation, abduction, and horizontal flexion, and scapular downward rotation.
  • Isometric action: stabilization of the shoulder girdle.
  • Innervation: axillary nerve.
  • Arterial supply: circumflex scapular artery (branch of subscapular artery); posterior circumflex humeral artery (branch of axillary artery).

Clinical Significance.

More.

References

Biel, A. (2015). Trail guide to the body: A hands-on guide to locating muscles, bones and more.

Cedars-Sinai. (2018). Vertebrae of the spine. Retrieved from https://www.cedars-sinai.org/health-library/diseases-and-conditions/v/vertebrae-of-the-spine.html

Clark, M., Lucett, S., Sutton, B. G., & National Academy of Sports Medicine. (2014). NASM essentials of corrective exercise training. Burlington, MA: Jones & Bartlett Learning.

Jenkins, G., & Tortora, G. J. (2012). Anatomy and Physiology: From Science to Life, 3rd Edition International Stu. John Wiley & Sons.

Muscolino, J. E. (2017). The muscular system manual: The skeletal muscles of the human body.

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Muscles: Infraspinatus.

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Anatomy & Physiology: Muscles—Infraspinatus.

Structure.

  • Origin: infraspinous fossa of scapula.
  • Insertion: middle facet of greater tubercle of humerus.

Function.

  • Concentric action: shoulder external/lateral rotation and adduction. Horizontal extension of arm.
  • Reverse mover action: lateral tilt of scapula.
  • Eccentric action: shoulder internal rotation; horizontal flexion; controls/restrains/slows scapular medial tilt.
  • Isometric action: stabilization of the shoulder girdle.
  • Innervation: suprascapular nerve.
  • Arterial supply: suprascapular artery; circumflex scapular artery.

Clinical Significance.

More.

References

Biel, A. (2015). Trail guide to the body: A hands-on guide to locating muscles, bones and more.

Cedars-Sinai. (2018). Vertebrae of the spine. Retrieved from https://www.cedars-sinai.org/health-library/diseases-and-conditions/v/vertebrae-of-the-spine.html

Clark, M., Lucett, S., Sutton, B. G., & National Academy of Sports Medicine. (2014). NASM essentials of corrective exercise training. Burlington, MA: Jones & Bartlett Learning.

Jenkins, G., & Tortora, G. J. (2012). Anatomy and Physiology: From Science to Life, 3rd Edition International Stu. John Wiley & Sons.

Muscolino, J. E. (2017). The muscular system manual: The skeletal muscles of the human body.

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Muscles: Supraspinatus.

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Anatomy & Physiology: Muscles—Supraspinatus.

Structure.

  • Origin: supraspinatus fossa of scapula.
  • Insertion: superior facet of the greater tubercle of humerus.

Function.

  • Concentric action: abduction of arm by assisting the deltoid.
  • Reverse mover action: downward rotation of scapula.
  • Eccentric action: controls/restrains/slows adduction and extension of arm; controls/restrains/slows scapular upward rotation.
  • Isometric action: stabilization of the shoulder girdle.
  • Innervation: suprascapular nerve.
  • Arterial supply: suprascapular artery (branch of thyrocervical artery).

Clinical Significance.

More.

References

Biel, A. (2015). Trail guide to the body: A hands-on guide to locating muscles, bones and more.

Cedars-Sinai. (2018). Vertebrae of the spine. Retrieved from https://www.cedars-sinai.org/health-library/diseases-and-conditions/v/vertebrae-of-the-spine.html

Clark, M., Lucett, S., Sutton, B. G., & National Academy of Sports Medicine. (2014). NASM essentials of corrective exercise training. Burlington, MA: Jones & Bartlett Learning.

Jenkins, G., & Tortora, G. J. (2012). Anatomy and Physiology: From Science to Life, 3rd Edition International Stu. John Wiley & Sons.

Muscolino, J. E. (2017). The muscular system manual: The skeletal muscles of the human body.

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Muscles: Teres Major.

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Anatomy & Physiology: Muscles—Teres Major.

Structure.

  • Origin: inferior angle of scapula.
  • Insertion: medial lip of intertubercular sulcus of humerus.

Function.

  • Concentric action: shoulder internal/medial rotation, adduction, and extension.
  • Reverse mover action: upward rotation of the scapula. Downward tilt of scapula.
  • Eccentric action: shoulder external rotation, abduction, and flexion. Controls/restrains/slows downward rotation and upward tilt of scapula.
  • Isometric action: stabilization of the shoulder girdle and scapula.
  • Innervation: lower subscapular nerve.
  • Arterial supply: circumflex scapular artery (branch of subscapular artery); thoracodorsal artery (continuation of subscapular artery).

Clinical Significance.

More.

References

Biel, A. (2015). Trail guide to the body: A hands-on guide to locating muscles, bones and more.

Cedars-Sinai. (2018). Vertebrae of the spine. Retrieved from https://www.cedars-sinai.org/health-library/diseases-and-conditions/v/vertebrae-of-the-spine.html

Clark, M., Lucett, S., Sutton, B. G., & National Academy of Sports Medicine. (2014). NASM essentials of corrective exercise training. Burlington, MA: Jones & Bartlett Learning.

Jenkins, G., & Tortora, G. J. (2012). Anatomy and Physiology: From Science to Life, 3rd Edition International Stu. John Wiley & Sons.

Muscolino, J. E. (2017). The muscular system manual: The skeletal muscles of the human body.

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Muscles: Latissimus Dorsi.

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Anatomy & Physiology: Muscles—Latissimus Dorsi.

Structure.

  • Origin: spinous processes of T7-T12; lumbar vertebrae; iliac and sacral crests; thoracolumbar fascia; ribs 9-12.
  • Insertion: inferior angle of scapula; intertubecular groove of humerus.

Function.

  • Concentric action: shoulder extension, adduction, and internal/medial rotation; draws arm inferiorly and posteriorly; scapular depression.
  • Reverse mover action: contralateral rotation of the pelvis and trunk at spinal joints. Ipsilateral elevation of pelvis at lumbosacral joint. Anterior tilt of pelvis. Trunk elevation.
  • Eccentric action: shoulder flexion, abduction, external rotation and spinal flexion. Controls/restrains/slows lateral rotation, abduction, and flexion of arm. Controls/restrains/slows ipsilateral rotation, ipsilateral depression, posterior tilt of pelvis. Controls/restrains/slows ipsilateral rotation, flexion, and depression of trunk. Controls/restrains/slows scapula.
  • Isometric action: stabilization of the lumbo-pelvic hip complex and shoulder. Stabilizes spinal joints.
  • Innervation: thoracodorsal nerves.
  • Arterial supply: thoracodorsal artery (branch of subscapular artery); dorsal branches of posterior intercostal arteries (branches of aorta).

Clinical Significance.

More.

References

Biel, A. (2015). Trail guide to the body: A hands-on guide to locating muscles, bones and more.

Cedars-Sinai. (2018). Vertebrae of the spine. Retrieved from https://www.cedars-sinai.org/health-library/diseases-and-conditions/v/vertebrae-of-the-spine.html

Clark, M., Lucett, S., Sutton, B. G., & National Academy of Sports Medicine. (2014). NASM essentials of corrective exercise training. Burlington, MA: Jones & Bartlett Learning.

Jenkins, G., & Tortora, G. J. (2012). Anatomy and Physiology: From Science to Life, 3rd Edition International Stu. John Wiley & Sons.

Muscolino, J. E. (2017). The muscular system manual: The skeletal muscles of the human body.

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Muscles: Pectoralis Major.

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Anatomy & Physiology: Muscles—Pectoralis Major.

Structure.

  • Origin: anterior surface of clavicular head; anterior surface of sternum, costal cartilage of ribs 2-6 or sometimes 1-7.
  • Insertion: greater tubercle and lateral lip of the intertubercular sulcus of of humerus.

Function.

  • Concentric action: shoulder flexion (clavicular fibers), horizontal adduction, and internal/medial rotation, protraction.
  • Reverse mover action: lateral deviation of trunk; trunk flexion at spinal joints; anterior translation of the trunk; scapular downward rotation; ipsilateral rotation of trunk; trunk elevation.
  • Eccentric action: shoulder extension, horizontal abduction, and external rotation, retraction. Controls/restrains/slows arm abduction, lateral rotation, extension, horizontal extension, flexion, and adduction. Controls/restrains/slows scapular retraction, protraction, elevation, and upward rotation. Controls/restrains/slows contralateral rotation, contralateral lateral deviation, posterior translation and depression of trunk.
  • Isometric action: stabilization of the shoulder girdle, clavicle, and scapula.
  • Innervation: medial and lateral pectoral nerves.
  • Arterial supply: pectoral branches of thoracoacromial trunk; posterior intercostal arteries (branches of aorta) and lateral thoracic artery (branch of axillary artery).

Clinical Significance.

More.

References

Biel, A. (2015). Trail guide to the body: A hands-on guide to locating muscles, bones and more.

Cedars-Sinai. (2018). Vertebrae of the spine. Retrieved from https://www.cedars-sinai.org/health-library/diseases-and-conditions/v/vertebrae-of-the-spine.html

Clark, M., Lucett, S., Sutton, B. G., & National Academy of Sports Medicine. (2014). NASM essentials of corrective exercise training. Burlington, MA: Jones & Bartlett Learning.

Jenkins, G., & Tortora, G. J. (2012). Anatomy and Physiology: From Science to Life, 3rd Edition International Stu. John Wiley & Sons.

Muscolino, J. E. (2017). The muscular system manual: The skeletal muscles of the human body.

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Muscles: Coracobrachialis.

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Anatomy & Physiology: Muscles—Coracobrachialis.

Structure.

  • Origin: coracoid process of scapula.
  • Insertion: middle of medial surface of shaft of humerus.

Function.

  • Concentric action: shoulder flexion and adduction. Horizontal arm flexion.
  • Reverse mover action: upward tilt of the scapula at the glenohumeral (GH) and scapulocostal (ScC) joints. Downward scapular rotation. Scapular protraction.
  • Eccentric action: controls/restrains/slows arm extension, abduction, and horizontal extension. Controls/restrains/slows scapular upward rotation, retraction, and downward tilt.
  • Isometric action: stabilization of the shoulder girdle and scapula.
  • Innervation: musculocutaneous nerve, C5, C6, C7.
  • Arterial supply: muscular branches of brachial artery; anterior circumflex humeral artery.

Clinical Significance.

More.

References

Biel, A. (2015). Trail guide to the body: A hands-on guide to locating muscles, bones and more.

Cedars-Sinai. (2018). Vertebrae of the spine. Retrieved from https://www.cedars-sinai.org/health-library/diseases-and-conditions/v/vertebrae-of-the-spine.html

Clark, M., Lucett, S., Sutton, B. G., & National Academy of Sports Medicine. (2014). NASM essentials of corrective exercise training. Burlington, MA: Jones & Bartlett Learning.

Jenkins, G., & Tortora, G. J. (2012). Anatomy and Physiology: From Science to Life, 3rd Edition International Stu. John Wiley & Sons.

Muscolino, J. E. (2017). The muscular system manual: The skeletal muscles of the human body.

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Muscles: Deltoid.

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Anatomy & Physiology: Muscles—Deltoid.

Structure.

  • Origin: lateral 1/3 (acromial extremity) of clavicle.
  • Insertion: deltoid tuberosity of humerus.

Function.

  • Concentric action: abduction at the glenohumeral (GH) joint. Arm flexion at GH joint (anterior deltoid). Medial rotation of the arm at GH (anterior deltoid). Horizontal flexion at the GH joint (anterior deltoid). Arm extension (posterior deltoid). Lateral rotation (posterior deltoid). Horizonal extension at GH (posterior deltoid).
  • Reverse mover actions: downward rotation of scapula at glenohumeral and scapulocostal joints; ipsilateral rotation of the trunk; contralateral rotation of the trunk.
  • Eccentric action: controls/restrains/slows arm adduction, extension, horizontal extension, flexion, horizontal flexion, lateral rotation, and medial rotation. Upward tilt of scapula such that inferior angle lifts off the thoracic wall.
  • Isometric action: stabilization of the shoulder girdle. Stabilize clavicle.
  • Innervation: axillary nerve.
  • Arterial supply: anterior and posterior circumflex humeral arteries (branches of axillary artery). Pectoral and deltoid branches of thoracoacromial trunk (branch of axillary artery).

Clinical Significance.

More.

References

Biel, A. (2015). Trail guide to the body: A hands-on guide to locating muscles, bones and more.

Cedars-Sinai. (2018). Vertebrae of the spine. Retrieved from https://www.cedars-sinai.org/health-library/diseases-and-conditions/v/vertebrae-of-the-spine.html

Clark, M., Lucett, S., Sutton, B. G., & National Academy of Sports Medicine. (2014). NASM essentials of corrective exercise training. Burlington, MA: Jones & Bartlett Learning.

Jenkins, G., & Tortora, G. J. (2012). Anatomy and Physiology: From Science to Life, 3rd Edition International Stu. John Wiley & Sons.

Muscolino, J. E. (2017). The muscular system manual: The skeletal muscles of the human body.

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Muscles: Trapezius Upper.

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Anatomy & Physiology: Muscles—Trapezius, Upper.

Structure.

  • Origin: superior nuchal line, ligamentum nuchae; spinous process of C7, T1-T12.
  • Insertion: lateral 1/3 of clavicle; acromion process of scapula.

Function.

  • Concentric action: cervical extension, lateral flexion and rotation; scapular elevation at scapulocostal joint (ScC); scapular retraction at ScC; upward rotation of the scapula at the ScC.
  • Reverse mover actions: head and neck extension at spinal joints; contralateral rotation of the head and neck at spinal joints; lateral flexion of the head and neck at spinal joints.
  • Eccentric action: cervical flexion, lateral flexion, and rotation; scapular depression. Controls/restrains/slows scapular protraction at ScC and ipsilateral rotation of the trunk at the spinal joints.
  • Isometric action: stabilization of the medial border of scapula and cervical spine.
  • Innervation: accessory XI nerve; cervical spinal nerves C3-C5.
  • Arterial supply: transverse cervical artery (branch from thyrocervical trunk), dorsal scapular artery (branch from subclavian artery).

Clinical Significance.

 

References

Biel, A. (2015). Trail guide to the body: A hands-on guide to locating muscles, bones and more.

Cedars-Sinai. (2018). Vertebrae of the spine. Retrieved from https://www.cedars-sinai.org/health-library/diseases-and-conditions/v/vertebrae-of-the-spine.html

Clark, M., Lucett, S., Sutton, B. G., & National Academy of Sports Medicine. (2014). NASM essentials of corrective exercise training. Burlington, MA: Jones & Bartlett Learning.

Jenkins, G., & Tortora, G. J. (2012). Anatomy and Physiology: From Science to Life, 3rd Edition International Stu. John Wiley & Sons.

Muscolino, J. E. (2017). The muscular system manual: The skeletal muscles of the human body.

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Muscles: Trapezius Middle.

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Anatomy & Physiology: Muscles—Trapezius, Middle.

Structure.

  • Origin: superior nuchal line, ligamentum nuchae; spinous process of C7, T1-T12.
  • Insertion: acromion process of scapula; superior aspect of scapular spine.

Function.

  • Concentric action: scapular retraction.
  • Reverse mover action: contralateral rotation of the trunk at spinal joints.
  • Eccentric action: scapular protraction and elevation. Controls/restrains/slows scapular protraction at ScC and ipsilateral rotation of trunk at spinal joints.
  • Isometric action: stabilization of the scapula.
  • Innervation: accessory XI nerve; cervical spinal nerves C3-C5.
  • Arterial supply: transverse cervical artery (branch from thyrocervical trunk), dorsal scapular artery (branch from subclavian artery).

Clinical Significance.

 

References

Biel, A. (2015). Trail guide to the body: A hands-on guide to locating muscles, bones and more.

Cedars-Sinai. (2018). Vertebrae of the spine. Retrieved from https://www.cedars-sinai.org/health-library/diseases-and-conditions/v/vertebrae-of-the-spine.html

Clark, M., Lucett, S., Sutton, B. G., & National Academy of Sports Medicine. (2014). NASM essentials of corrective exercise training. Burlington, MA: Jones & Bartlett Learning.

Jenkins, G., & Tortora, G. J. (2012). Anatomy and Physiology: From Science to Life, 3rd Edition International Stu. John Wiley & Sons.

Muscolino, J. E. (2017). The muscular system manual: The skeletal muscles of the human body.