Effect of an anterior-sloped brace joint on anterior tibial translation and axial tibial rotation: a motion analysis study.
BACKGROUND
Anterior tibial translation and axial tibial rotation are major biomechanical factors involved in anterior cruciate ligament injuries. This study sought to evaluate a brace prototype designed with an anterior-sloped joint, in terms of its efficacy in attenuating anterior tibial translation and axial tibial rotation during landing, using a motion analysis approach.


METHODS
Ten healthy male subjects performed single-leg landing tasks from a 0.6-m height with and without the brace prototype. Ground reaction force and kinematics data were obtained using a motion-capture system and force-plates. Anterior tibial translation and axial tibial rotation were determined based on tibial and femoral marker reference frames. Vertical and anterior-posterior ground reaction forces, hip, knee and ankle joint range-of-motions and angular velocities, anterior tibial translation and axial tibial rotation were compared between unbraced and braced conditions using Wilcoxon signed-rank test.


RESULTS
We found no significant difference in peak vertical and anterior-posterior ground reaction forces (p=0.770 and p=0.332 respectively) between unbraced and braced conditions. Knee joint range-of-motion and angular velocity were lower (p=0.037 and p=0.038 respectively) for braced condition than unbraced condition. Anterior tibial translation and axial tibial rotation were reduced (p=0.027 and p=0.006 respectively) in braced condition, compared to unbraced condition.


CONCLUSIONS
The anterior-sloped brace joint helps to attenuate anterior tibial translation and axial tibial rotation present in the knee joint during landing. It is necessary to test the brace prototype in a sporting population with realistic sports landing situations in order to assess its effectiveness in lowering anterior cruciate ligament injury risk.
Yeow
C H
CH
Division of Bioengineering, National University of Singapore, Singapore.
Gan
W L
WL
Lee
P V S
PV
Goh
J C H
JC
D000328:Adult; D001696:Biomechanical Phenomena; D001915:Braces; D006801:Humans; D007717:Knee / Q000473:pathology; D007718:Knee Injuries / Q000503:physiopathology*; D007719:Knee Joint / Q000503:physiopathology*; D008297:Male; D009038:Motion; D016059:Range of Motion, Articular; D012306:Risk; D013977:Tibia / Q000473:pathology / Q000503:physiopathology*