Category: Muscles

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Anatomy & Physiology: Muscles—Flexor Pollicis Brevis.

Structure.

• Origin: flexor retinaculum, trapezium, capitate, and trapezoid.
• Insertion: lateral side of proximal phalanx of thumb.

Function.

• Concentric action: flexes thumb at carpometacarpal and metacarpophalangeal joints; thumb abduction at CMC.
• Reverse mover action: flexion of trapezium at CMC; flexion of thumb at MCP; abduction of trapezium at CMC.
• Eccentric action: controls/restrains/slows thumb extension at CMC and MCP; adduction of thumb at CMC.
• Isometric action: stabilizes thumb at CMC and MCP.
• Innervation: median and ulnar nerves.
• Arterial supply: branches of radial artery.

Clinical Significance.

More.

• https://www.anatomynext.com/flexor-pollicis-brevis/
• https://www.youtube.com/watch?v=whEJRK88eeo
• https://www.youtube.com/watch?v=j-_9CeUDyFA
• https://www.nielasher.com/blogs/video-blog/trigger-point-therapy-adductor-pollicis-and-opponens-pollicis

Flexor pollicis brevis manus. Used with permission by 3D4Medical.

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.

Download these notes.

Anatomy & Physiology: Muscles—Abductor Pollicis Brevis.

Structure.

• Origin: flexor retinaculum, scaphoid, and trapezium.
• Insertion: lateral side of proximal phalanx of thumb.

Function.

• Concentric action: abducts thumb at carpometacarpal joint. Lesser: thumb flexion at MCO; thumb extension at CMC and IP.
• Reverse mover action: abudction of trapezium at CMC; flexion of thumb at MCP; trapezium extension at CMC; extension of proximal phalanx of thumb at IP.
• Eccentric action: controls/restrains/slows thumb adduction at CMC; thumb extension at MCP; flexion of thumb at CMC and IP.
• Isometric action: stabilizes CMC, MCP, and IP joints of thumb.
• Innervation: median nerve.
• Arterial supply: radial artery.

Clinical Significance.

More.

• https://www.anatomynext.com/abductor-pollicis-brevis/
• https://www.youtube.com/watch?v=YIkt5uj3DrI
• https://www.youtube.com/watch?v=ZGlXpSffRyw
• https://www.youtube.com/watch?v=gUooutTt2tc

Abductor pollicis brevis manus. Used with permission by 3D4Medical.

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.

Download these notes.

Anatomy & Physiology: Muscles—Extensor Indicis.

Structure.

• Origin: posterior surface of ulna.
• Insertion: tendon of extensor digitorum of index finger.

Function.

• One of the deep distal four group.
• Concentric action: extends distal and middle phalanges of index finger at interphalangeal joints, proximal phalanx of index finger at metacarpophalangeal joint and hand at wrist joint. Lesser: adduction index finger at MCP; supination.
• Reverse mover action: extension of 2nd metacarpal at MCP; extension of proximal phalanx at PIP; middle phalanx extension at DIP.
• Eccentric action: controls/restrains/slows index finger flexion at MCP, DIP, PIP; wrist flexion; abduction of index finger; pronation.
• Isometric action: stabilize MCP, DIP, PIP of index finger; wrist; radioulnar joints.
• Innervation: deep radial nerve.
• Arterial supply: posterior interosseus artery; perforating branches of anterior interosseus artery.

Clinical Significance.

Extensor indicis. Used with permission by 3D4Medical.

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.

Download these notes.

Anatomy & Physiology: Muscles—Extensor Pollicis Longus.

Structure.

• Origin: posterior surface of middle of ulna and interosseous membrane.
• Insertion: base of distal phalanx of thumb.

Function.

• One of the deep distal four group.
• Concentric action: extends distal phalanx of thumb at interphalangeal joint, first metacarpal of thumb at carpometacarpal joint, and abducts hand at wrist joint. Lesser: lateral rotation of thumb at CMC; wrist extension; radial deviation; supination; adduction of thumb at CMC.
• Reverse mover action: extend trapezium at CMC; extend 1st metacarpal at MCP; extend proximal phalanx at IP joint; medial rotation of trapezium; wrist extension; radial deviation; supination; medial rotation at shoulder; trapezium adduction at CMC.
• Eccentric action: controls/restrains/slows flexion at CMC, MCP and IP of thumb; medial rotation of metacarpal and lateral rotation of trapezium at CMC; wrist flexion; ulnar deviation; pronation; abduction of CMC at thumb.
• Isometric action: stabilize CMC, MCP, IP; wrist; radioulnar joints.
• Innervation: deep radial nerve.
• Arterial supply: posterior interosseus artery; perforating branches of anterior interosseus artery.

Clinical Significance.

Extensor pollicis longus manus. Used with permission by 3D4Medical.

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.

Download these notes.

Anatomy & Physiology: Muscles—Extensor Pollicis Brevis.

Structure.

• Origin: posterior surface of middle of ulna and interosseous membrane.
• Insertion: base of proximal phalanx of thumb.

Function.

• One of the deep distal four group.
• Concentric action: extends proximal phalanx of thumb at metacarpophalangeal joint, first metacarpal of thumb at carpometacarpal joint, and abducts hand at wrist joint. Lesser: lateral rotation of thumb at CMC; radial deviation.
• Reverse mover action: extension of carpal bone trapezium at CMC, extension first metacarpal at MCP; abduction of trapezium at CMC; medial rotation of trapezium at CMC; radial deviation.
• Eccentric action: controls/restrains/slows flexion at CMC and MCP of thumb; adduction at CMC of thumb; medial rotation of metacarpal and lateral rotation of carpal trapezium at CMC of thumb; wrist ulnar deviation.
• Isometric action: stabilize CMC and MCP of thumb, wrist joint.
• Innervation: deep radial nerve.
• Arterial supply: posterior interosseus artery; perforating branches of anterior interosseus artery.

Clinical Significance.

Extensor pollicis brevis manus. Used with permission by 3D4Medical.

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.

Download these notes.

Anatomy & Physiology: Muscles—Abductor Pollicis Longus.

Structure.

• Origin: posterior surface of middle of radius and ulna and interosseous membrane.
• Insertion: first metacarpal.

Function.

• One of four deep distal four group.
• Concentric action: abducts and extends thumb at carpometacarpal joint and abducts hand at wrist joint. Lesser: lateral rotation of thumb at CMC; radial deviation; wrist flexion; supination.
• Reverse mover action: abducts and extends thumb at carpometacarpal joint and abducts hand at wrist joint. Lesser: lateral rotation of thumb at CMC; radial deviation; wrist flexion; supination.
• Eccentric action: controls/restrains/slows thumb adduction, flexion, medial rotation at CMC; adduction, flexion, and lateral rotation of trapezium at CMC; wrist ulnar deviation and extension; pronation.
• Isometric action: stabilize first CMC, wrist, radioulnar joints.
• Innervation: deep radial nerve.
• Arterial supply: posterior interosseus artery, perforating branches of anterior interosseus artery.

Clinical Significance.

Abdcutor pollicis longus manus. Used with permission by 3D4Medical.

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.

Download these notes.

Anatomy & Physiology: Muscles—Extensor Digiti Minimi.

Structure.

• Origin: lateral epicondyle of humerus.
• Insertion: tendon of extensor digitorum on fifth phalanx.

Function.

• Concentric action: extends proximal phalanx of little finger at MCP, DIP, PIP joints; and hand at wrist joint (wrist extension). Lesser: medial rotation of little finger; elbow extension; ulnar deviation.
• Reverse mover action: extends proximal phalanx of little finger at MCP, DIP, PIP joints; and hand at wrist joint (wrist extension). Lesser: medial rotation of little finger; elbow extension; ulnar deviation.
• Eccentric action: controls/restrains/slows flexion at MCP, DIP, PIP; wrist flexion; lateral rotation of little finger; elbow flexion.
• Isometric action: stabilize MCP, DIP, PIP, wrist, radioulnar joints, elbow joint.
• Innervation: deep radial nerve.
• Arterial supply: posterior interosseus artery.

Clinical Significance.

Extensor digiti minimi. Used with permission by 3D4Medical.

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.

Download these notes.

Anatomy & Physiology: Muscles—Extensor Digitorum.

Structure.

• Origin: lateral epicondyle of humerus.
• Insertion: distal and middle phalanges of each finger.

Function.

• Concentric action: extends distal and middle phalanges of each finger at interphalangeal joints, proximal phalanx of each finger at metacarpophalangeal joint, and hand at wrist joint. Lesser: medial rotation of pinky finger at CMC joint; elbow extension.
• Reverse mover action: extension at MCP, DIP, PIP joints; wrist extension; lateral rotation of hamate; elbow extension.
• Eccentric action: controls/restrains/slows MCP, DIP, PIP flexion; wrist flexion; pinky finger lateral rotation; elbow flexion.
• Isometric action: stabilize MCP, DIP, PIP, wrist, radioulnar joint, elbow joint.
• Innervation: radial nerve.
• Arterial supply: posterior interosseus artery.

Clinical Significance.

Extensor digitorum. Used with permission by 3D4Medical.

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.

Download these notes.

Anatomy & Physiology: Muscles—Flexor Pollicis Longus.

Structure.

• Origin: anterior surface of radius and interosseous membrane (sheet of fibrous tissue that holds shafts of ulna and radius together).
• Insertion: base of distal phalanx of thumb.

Function.

• Concentric action: flexes distal phalanx of thumb at interphalangeal joint; wrist flexion. Lesser: radial deviation; forearm flexion; pronation.
• Reverse mover action: metacarpal flexion, proximal phalanx flexion, radial deviation, elbow flexion, pronation, lateral rotation at shoulder joint.
• Eccentric action: controls/restrains/slows CMC, MCP, and PIP extension; wrist extension; ulnar deviation; elbow extension; supination.
• Isometric action: stabilize CMC, MCP, PIP, wrist, and elbow.
• Innervation: median nerve.
• Arterial supply: radial artery; anterior interosseus artery.

Clinical Significance.

Flexor pollicis longus. Used with permission by 3D4Medical.

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.

Download these notes.

Anatomy & Physiology: Muscles—Flexor Digitorum Profundus.

Structure.

• Origin: anterior medial surface of body of ulna.
• Insertion: base of distal phalanx of each finger.

Function.

• Concentric action: flexes distal and middle phalanges of each finger at interphalangeal joints, proximal phalanx of each finger at metacarpophalangeal joint, and hand at wrist joint.
• Reverse mover action: flexion of metacarpals at MCP, flex proximal phalanges at PIP, wrist flexion.
• Eccentric action: controls/restrains/slows MCP, PIP, and DIP joint extension, wrist extension.
• Isometric action: stabilize wrist and finger joints.
• Innervation: median and ulnar nerves.
• Arterial supply: ulnar and radial arteries; anterior interosseus artery.

Clinical Significance.

Flexor digitorum profundus. Used with permission by 3D4Medical.

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.