The Effect of Functional Knee Bracing on the Anterior Cruciate Ligament in the Weightbearing and Nonweightbearing Knee

We investigated the effect of functional bracing on anterior cruciate ligament strain in humans by arthro scopic implantation of a differential variable reluctance transducer on the ligament and measurement of its strain behavior. Strains were measured while "injury mechanism" loads were a...

Full description

Saved in:
Bibliographic Details
Published in:The American journal of sports medicine 1997-05, Vol.25 (3), p.353-359
Main Authors: Beynnon, Bruce D., Johnson, Robert J., Fleming, Braden C., Peura, Glenn D., Renstrom, Per A., Nichols, Claude E., Pope, Malcolm H.
Format: Article
Language:English
Subjects:
Adult
Anterior Cruciate Ligament - physiology
Anterior Cruciate Ligament Injuries
Arthroscopy
Biological and medical sciences
Biomechanical Phenomena
Braces
Diseases of the osteoarticular system
Female
Humans
Joints
Knee
Knee Injuries - physiopathology
Knee Injuries - therapy
Knee Joint - physiology
Ligaments
Male
Medical sciences
Middle Aged
Miscellaneous. Osteoarticular involvement in other diseases
Orthopedic braces
Orthopedic Fixation Devices
Physiological aspects
Range of motion
Sports injuries
Sports medicine
Weight-Bearing
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We investigated the effect of functional bracing on anterior cruciate ligament strain in humans by arthro scopic 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 un braced conditions. For the unbraced knee, there was a significant increase in ligament strain values when sub jects went from a seated position (minimal shear and compressive loads across the knee) to a standing pos ture (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 liga ment 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. Adjust ment of strap tension between low and high settings did not modulate the protective effect of the brace on the ligament.
ISSN:0363-5465
1552-3365
DOI:10.1177/036354659702500314