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.
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.
