Lachman’s Test

Other Known Aliasesnone

Definitionpassive accessory movement test of the knee performed to identify the integrity of the anterior cruciate ligament

Clinical Significance Place the patient’s knee in about 20-30 degrees flexion and externally rotated slightly. The examiner should place one hand behind the tibia and the other on the patient’s thigh. It is important that the examiner’s thumb be on the tibial tuberosity. On pulling the tibia anteriorly, an intact ACL should prevent forward translational movement of the tibia on the femur. A positive test is > 2mm of movement compared to the unaffected knee.

HistoryNamed after John Lachman (1919-2007), who was an American orthopaedic surgeon and received his medical doctorate from the Temple University School of Medicine in 1945. He was described as a prolific teacher, mentor, and surgeon making his mark across students, faculty, and patients over illustrious career. As a testament to this, his eponymous test was published by one of his colleagues who named and attributed it to him in 1987.


  1. Firkin BG and Whitwirth JA.  Dictionary of Medical Eponyms. 2nd ed.  New York, NY; Parthenon Publishing Group. 1996.
  2. Bartolucci S, Forbis P.  Stedman’s Medical Eponyms.  2nd ed.  Baltimore, MD; LWW.  2005.
  3. Yee AJ, Pfiffner P. (2012).  Medical Eponyms (Version 1.4.2) [Mobile Application Software].  Retrieved http://itunes.apple.com.
  4. Whonamedit – dictionary of medical eponyms. http://www.whonamedit.com
  5. Up To Date. www.uptodate.com
  6. Gurtler RA, Stine R, Torg JS. Lachman test evaluated. Quantification of a clinical observation. Clinical orthopaedics and related research. 1987; [pubmed]
  7. Physiopaedia. Lachman Test. https://www.physio-pedia.com/Lachman_Test

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s