Comments on an Article Abstract

by Mitch Doyle

Assessment of the Lower Extremity


Beynnon B, Fleming B, Churchill D, Brown D. The effect of Anterior Cruciate Ligament Deficiency and Functional Bracing on Translation of the Tibia Relative to the Femur During Non-Weightbearing and Weightbearing. The American Journal of Sports Medicine. 2003; 31:99-105


In this study, the researchers attempted to measure the effectiveness of bracing ACL deficient knees by measuring the anterior translation of the tibia in a non-weightbearing position, a weightbearing position, and during the transition between the two (e.g. landing). Previous studies of this kind only included measurements taken in a non-weightbearing position, so the goal of this study was to effectively evaluate the functional protective capabilities of various ACL braces. [1]

Nine subjects were used to carry out this study. Each subject had one chronically ACL deficient knee and one healthy knee. A device [2] that measured anterior translation of the tibia in relation to the femur was used to record data in each position (weightbearing, non-weightbearing, transitional). Three braces were evaluated in the study: the DonJoy Legend, the SofTec Genu, and the Townsend Rebel. Each subject was tested without a brace and then fitted with a brace and tested again. The braces were tested on each subject in random order. The translation of the healthy knee was then compared to the translation of the ACL deficient knee in each subject.

It was determined that on average, bracing held anterior translation within normal limits during weightbearing and non-weightbearing. During the transition [3] between the two, however, the translation in the injured knee averaged 3.5 times more than the translation in the healthy knee both with and without bracing. [4] The DonJoy Legend provided the most protection out of the braces tested, and the Townsend Rebel was the least successful in limiting translation.

It seems that the findings of this study successfully accomplished the initial goals of the researchers. The results would be more conclusive if more subjects were included in the research. It would also be interesting to determine whether or not normal wear and tear on ACL braces significantly affects anterior tibial translation. [5]

After reading this article, I feel that surgery and bracing together is by far a better option for ACL deficient patients than is bracing alone. While bracing limits some anterior translation of the tibia during weightbearing and non-weightbearing, it is unable to withstand the forces of jumping, landing, etc. This increased laxity in the knee joint, even with bracing, may lead to further injuries to the joint over time.











1. Good.


2. What type of device was used? Be specific.







3. How was each measurement conducted? Be specific about how "transition" measurement was taken.

4. Was hamstring strength in deficient knee measured? Were there similar strengths between "good" and "bad" knees? This may affect anterior translation of the tibia.




5. Do you think a jump/landing training regime would influence transition results? Need more information in this paragraph.



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