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Quick clinical tip: Elson’s test for the finger


Extensor Tendon Laceration Finger 6 smInjuries to the hand are fraught with multiple, concurrent injuries. Many injuries may have chronic debilitating complications, if not detected early. One such example is a finger laceration with a concurrent extensor tendon injury, causing delayed boutonniere deformity formation and limited function. Review the anatomy of the extensor tendon. View the video on how to perform the Elson’s test to detect a central slip tendon injury.

Finger anatomy

The extensor tendon complex of each finger consists of a central band (or central slip) and paired lateral bands.

  • Central band: Portion of the extensor tendon which inserts on the dorsal aspect of the middle phalanx
  • Lateral bands: Extends from the interosseous muscles and inserts at the base of the distal phalanx

CentralSlipExtensorTendon sm


The upper diagram shows normal anatomy, and the lower diagram shows a central slip tendon laceration (denoted by blue asterisk).

A ruptured central slip tendon injury will cause the lateral bands to slide volarly and cause abnormal flexion of the PIP joint and extension of the DIP joint.

Elson’s test

The Elson’s test essentially isolates the central band/slip of the extensor tendon complex [1]. [original Elson test PDF]

  1. Position the patient’s PIP in 90-degrees flexion. This normally keeps the central band taut and the lateral bands loose.
  2. Ask the patient to extend the PIP, while the provider’s finger applies counterforce at the middle phalanx.
  3. NORMAL Elson’s test: Results in active extension of the PIP joint and a floppy DIP.
  4. ABNORMAL Elson’s test: Results in no active extension of the PIP joint and a slightly extended, taut DIP.



  1. Rubin J, Bozentka DJ, Bora FW. Diagnosis of closed central slip injuries. A cadaveric analysis of non-invasive tests. J Hand Surg Br. 1996 Oct;21(5):614-6. Pubmed
Michelle Lin, MD
ALiEM Editor-in-Chief
Academy Endowed Chair of EM Education
Professor of Clinical Emergency Medicine
University of California, San Francisco
Michelle Lin, MD
Michelle Lin, MD

Latest posts by Michelle Lin, MD (see all)

  • Cam_8518

    Awesome post Dr. Lin!….I’m lovin’ the new ortho related injury exam pearls the past few weeks. As a new PA in EM the education from your website is truly invaluable in helping me grow and learn as a practitioner. I can’t thank all of you enough for your hard work and dedication.

    • Michelle

      @Cam_8518 I’m thrilled that you like this recent run of quick tips in the orthopedics arena. I personally use them to help teach the residents and medical students on shift so that I don’t have to google-search for these pearls. This is purely a selfish endeavor, and I’m glad that it helps others too. So many pitfalls in this field which can be avoided with a strong knowledge of orthopedic complications, potential injury patterns, and focused clinical exam techniques. Best of luck to you!

  • Brian Lin, MD, FACEP

    Hey Michelle! this is great. I am planning to talk about extensor tendon injuries at my ACEP talk this year and I may just need to borrow this awesome video from you 🙂 I’ve also recently read about an excellent modfication of the Elson test that you should check out:

    Schreuders TAR, Soeters JNM, Hovius SER, Stam HJ. A modification of Elson’s test for the diagnosis of an acute extensor central slip injury. British J of Hand Therapy. 2006: 11(4), 112-113.

    It’s much easier to remember, and this test also has the advantage of simultaneous contralateral side testing. Cheers!

    • Michelle

      Hey Brian: What a coincidence that you giving a talk covering this at ACEP. You are welcome to use the video. Yes, I saw the article cited just recently as well. I didn’t have a great photo but an interesting idea of testing against the patient’s own contralateral finger. Good luck at your talk!

    • Brian Berger

      I really like this modification. Next time I’m in the ED, Michelle!