Document Detail


The effect of functional knee bracing on the anterior cruciate ligament in the weightbearing and nonweightbearing knee.
MedLine Citation:
PMID:  9167816     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
We investigated the effect of functional bracing on anterior cruciate ligament strain in humans by arthroscopic implantation of a differential variable reluctance transducer on the ligament and measurement of its strain behavior. Strains were measured while "injury mechanism" loads were applied to the weightbearing and nonweightbearing knees for both braced and unbraced conditions. For the unbraced knee, there was a significant increase in ligament strain values when subjects went from a seated position (minimal shear and compressive loads across the knee) to a standing posture (substantial shear and compressive loads across the knee). Similar strain values were found between these same seated and standing postures when a 140-N anterior-directed load was applied to the tibia. This indicates that the ligament is strained during weightbearing and demonstrates that the compressive load across the knee produced during weightbearing does not significantly reduce ligament strain values in comparison with the unweighted joint with relaxed muscles for the 140-N load limit of our anterior shear test. Bracing produced a protective effect on the ligament by significantly reducing the strain values for anterior-directed loading of the tibia up to 140 N with the knee in both weightbearing and nonweightbearing conditions. Likewise, bracing produced a protective effect on the ligament by significantly reducing strain values in response to internal-external torque of the tibia up to 6 N-m with the knee nonweightbearing. The brace strap that contacts the tibia just distal to the insertion of the patellar tendon was instrumented with a load sensor, allowing us to measure the posterior-directed loads applied by the brace to the tibia. Adjustment of strap tension between low and high settings did not modulate the protective effect of the brace on the ligament.
Authors:
B D Beynnon; R J Johnson; B C Fleming; G D Peura; P A Renstrom; C E Nichols; M H Pope
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  The American journal of sports medicine     Volume:  25     ISSN:  0363-5465     ISO Abbreviation:  Am J Sports Med     Publication Date:    1997 May-Jun
Date Detail:
Created Date:  1997-07-18     Completed Date:  1997-07-18     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  7609541     Medline TA:  Am J Sports Med     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  353-9     Citation Subset:  IM    
Affiliation:
Department of Orthopaedics and Rehabilitation, McClure Musculoskeletal Research Center, University of Vermont College of Medicine, Burlington 05405-0084, USA.
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MeSH Terms
Descriptor/Qualifier:
Adult
Anterior Cruciate Ligament* / injuries,  physiology
Arthroscopy
Biomechanics
Braces*
Female
Humans
Knee Injuries / physiopathology*,  therapy
Knee Joint / physiology*
Male
Middle Aged
Orthopedic Fixation Devices*
Weight-Bearing
Grant Support
ID/Acronym/Agency:
R01 AR 39213/AR/NIAMS NIH HHS

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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