HOME HELP CONTACT US SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:
Sign In to gain access to subscriptions and/or personal tools.

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Request Permissions Request Reprints Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Howell, S. M. Search for Related Content PubMed Articles by Howell, S. M.

Anterior tibial translation during a maximum quadriceps contraction: Is it clinically significant?

David Grant Medical Center, Travis Air Force Base, California

Quadriceps exercises are used sparingly in the early rehabilitation of ACL reconstructions because of con cern about prematurely stretching the ACL graft. The aim of this study was to determine if a maximum isometric quadriceps contraction significantly translates the tibia anteriorly at 15°, 30°, 45°, 60°, and 75° of flexion. Secondly, the role of the ACL in knee stability was analyzed by comparing the amount of tibial trans lation in normal, ACL deficient, and reconstructed knees. Thirdly, the location in the motion arc where a quadriceps contraction produces anterior tibial transla tion was determined.

Anterior tibial translation was measured using an arthrometer (KT-1000) during an 89 N and manual maximum translation applied to the knee at rest. The manual maximum translation test determines the mag nitude of anterior tibial translation produced by a high anterior force applied directly to the proximal calf. These translations were compared to the tibial translation intrinsically induced by a quadriceps contraction. Test ing was performed in normal ( N = 22), ACL deficient (N=10), and reconstructed (N = 10) knees.

Anterior tibial translation produced by a maximum quadriceps contraction was measured at 15°, 30°, 45°, 60°, and 75° of flexion. The extension exercise resulted in less anterior tibial displacement than an 89 N drawer and half the translation produced by a manual maximum translation (P < 0.001). Instrumented laxity testing pro duced greater anterior translation of the tibia than a maximum isometric quadriceps contraction. Anterior tibial translation was the same during maximum iso metric knee extension in all tested knees. Anterior translation in the isometrically loaded knee occurred during the terminal 60° of knee extension, and was controlled by the compression forces driving the con gruent articular surfaces together, and not the ACL.

Instrumented laxity testing is an accepted technique that has been safely used to serially measure knee stability after an ACL reconstruction. Early postopera tive knee extension exercises can be expected to in duce less strain in the ACL than instrumented laxity testing. These data raise the question of whether the anterior tibial displacement produced by a maximum quadriceps contraction is detrimental to a recently re constructed ACL.

This article has been cited by other articles:

				S. M. Howell and K. W. Lawhorn Gravity Reduces the Tibia When Using a Tibial Guide That Targets the Intercondylar Roof Am. J. Sports Med., October 1, 2004; 32(7): 1702 - 1710. [Abstract] [Full Text] [PDF]

				G. DeMorat, P. Weinhold, T. Blackburn, S. Chudik, and W. Garrett Aggressive Quadriceps Loading Can Induce Noncontact Anterior Cruciate Ligament Injury Am. J. Sports Med., March 1, 2004; 32(2): 477 - 483. [Abstract] [Full Text] [PDF]

				B. C. Fleming, G. Ohlen, P. A. Renstrom, G. D. Peura, B. D. Beynnon, and G. J. Badger The Effects of Compressive Load and Knee Joint Torque on Peak Anterior Cruciate Ligament Strains Am. J. Sports Med., September 1, 2003; 31(5): 701 - 707. [Abstract] [Full Text] [PDF]

				M. E. Steiner, S. K. Koskinen, C. S. Winalski, S. D. Martin, and M. Haymen Dynamic Lateral Patellar Tilt in the Anterior Cruciate Ligament-Deficient Knee: A Magnetic Resonance Imaging Analysis Am. J. Sports Med., September 1, 2001; 29(5): 593 - 599. [Abstract] [Full Text] [PDF]

				B. D. Beynnon, R. J. Johnson, B. C. Fleming, C. J. Stankewich, P. A. Renstrom, and C. E. Nichols The Strain Behavior of the Anterior Cruciate Ligament During Squatting and Active Flexion-Extension: A Comparison of an Open and a Closed Kinetic Chain Exercise Am. J. Sports Med., December 1, 1997; 25(6): 823 - 829. [Abstract] [PDF]

				A. K. Aune, P. W. Cawley, and A. Ekeland Quadriceps Muscle Contraction Protects the Anterior Cruciate Ligament During Anterior Tibial Translation Am. J. Sports Med., March 1, 1997; 25(2): 187 - 190. [Abstract] [PDF]

				B. D. Beynnon, B. C. Fleming, R. J. Johnson, C. E. Nichols, P. A. Renstrom, and M. H. Pope Anterior Cruciate Ligament Strain Behavior During Rehabilitation Exercises In Vivo Am. J. Sports Med., January 1, 1995; 23(1): 24 - 34. [Abstract] [PDF]

				A. B. Zavatsky, D. J. Beard, and J. J. O'Connor Cruciate Ligament Loading During Isometric Muscle Contractions: A Theoretical Basis for Rehabilitation Am. J. Sports Med., June 1, 1994; 22(3): 418 - 423. [Abstract] [PDF]

				M. E. Maitland, R. Lowe, S. Stewart, T. Fung, and G. D. Bell Does Cybex testing increase knee laxity after anterior cruciate ligament reconstructions? Am. J. Sports Med., September 1, 1993; 21(5): 690 - 695. [Abstract] [PDF]