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Flexor Pollicis Longus Anatomy: Origin, Insertion, Action

Flexor Pollicis Longus Anatomy Study

Flexor Pollicis Longus Muscle

Origin: Middle anterior surface of the radius and the interosseous membrane. The muscle may also originate from the lateral border of the coronoid process of the ulna or the medial epicondyle of the humerus.
Insertion: Palmar aspect of the base of the distal phalanx of thumb
Action: Flexion of the thumb
Blood Suppy: Muscular branches from the radial artery and the anterior interosseous artery from the ulnar artery.
Innervation:  Interosseous branch of the median nerve (C8, T1).

Synergist: Pronator Teres, Pronator Quadratus, Flexor Carpi Radialis,  Flexor Digitorum Superficialis, Flexor Carpi Ulnaris, Flexor Digitorum Profundus

Antagonist: Brachioradialis, Extensor Carpi Radialis Brevis, Extensor Carpi Radialis Longus,Supinator, Abductor Pollicis Longus, Extensor Pollicis Longus, Extensor Pollicis Brevis, Extensor Digitorum, Extensor Carpi Ulnaris, Extensor Digiti Minimi, Extensor Indicis

For pain and symptom information see: Flexor Pollicis Longus Thumb Pain


Primary Actions of the Flexor Pollicis Longus:

1. Flexion of the thumb at the interphalangeal joint

  • Agonists: None
  • Antagonists: Extensor Flexor Pollicis Longus

Secondary Actions of the Flexor Pollicis Longus:

2. Flexion of the thumb at the carpometacarpal joint

  • Agonists: Flexor Pollicis Brevis, Adductor Pollicis, Opponens Pollicis
  • Antagonists: Extensor Pollicis Brevis, Extensor Pollicis Longus, Abductor Pollicis Longus

3. Assists with flexion of the wrist

  • Agonists: Flexor Carpi Radialis, Palmaris Longus, Flexor Carpi Ulnaris
  • Antagonists: Extensor Carpi Radialis Longus, Extensor Carpi Radialis Brevis, Extensor Carpi Ulnaris

Musculoskeletal Anatomy Flashcards

Musculoskeletal Anatomy Flashcards Musculoskeletal Flashcards Are you a student or professional therapist who needs to brush up on the musculoskeletal system? Dr. Joseph E. Muscolino DC has developed a comprehensive set of flashcards that will help develop a mind’s picture of exactly where the muscles lie under the skin. A highly recommended study aid for students. Great for non students who want an easy comprehensive anatomy guide.


Trail Guide To The Body


The Trail Guide To The Body is another excellent book to help you learn the musculature of the human body. Though the book is geared toward massage therapists and physical therapist assistants, the book with its illustrations and text helps anyone gain a thorough understanding of the human musculoskeletal system and movement. I highly recommend this book for anyone studying anatomy and believe that MTs, PTAs, and teachers of body movements should have this book in their possession. I also highly recommend this book for the lay person who wants to gain understanding of the muscle, skeletal system and how our bodies move. This book will not disappoint!



The Trigger Point Therapy Workbook – Claire Davies, Amber Davies, and David G. Simons

Basic Clinical Massage Therapy: Integrating Anatomy and Treatment – James H. Clay and David M. Pounds

Trigger Point Therapy for Myofascial Pain – Donna Finando and Steven Finando