Global Quasi-Static Mechanical Characterization of the Human Knee Under Single- and Multi-Axis Unconstrained Loading Conditions

Abstract

A substantial number of knee injuries are reported in the United States annually, and are principally observed among young athletes. ACL (anterior cruciate ligament) injury is one of the most common and devastating knee injuries [1]. Many factors influence such injuries, from anatomical variability to magnitude and direction of loading. A better understanding of knee biomechanics and injury mechanisms may improve current preventative, surgical and rehabilitation strategies, and thus, mediate injury risk. Considerable study of knee joint biomechanics under various modes of loading has been undertaken [2–4]. Additional work is needed to characterize the effects of different loading factors on knee biomechanics, especially ACL loading patterns under more physiologically relevant conditions. The purpose of this study is to develop a new technique to investigate the effects of various single- and multi-axes loading conditions on knee kinematics, ACL and MCL (medial collateral ligament) strains, and TF (tibiofemoral) articular cartilage pressure distribution under quasistatic loading conditions that simulate various weight bearing activities.

Uni-directional coupling between tibiofemoral frontal and axial plane rotation supports valgus collapse mechanism of ACL injury

“…Specimens were tested using a custom, passive 6-DOF Force Couple Testing System (FCTS, Fig 1A) (Kiapour et al, 2011; Kiapour et al, 2012a; Kiapour et al, 2012b). This system utilized a combination of servo-electric actuators and static weights to drive multiple lightweight low friction cable-pulley systems that generate unconstrained forces and pure moments in all three anatomical planes (Fig 1B).…”

Diagnostic Value of Knee Arthrometry in the Prediction of Anterior Cruciate Ligament Strain During Landing

“…It was assumed that the mean strain across the ACL’s AM bundle was equal to the change in length of the measured segment divided by the reference length (Kiapour AM, Quatman CE, Ditto RC, et al, “Influence of Axial Rotation Moments on ACL Strain: A Cadaveric Study of Single- and Multi-Axis Loading of the Knee.” Paper presented at the proceedings of 37th ASB annual meeting, 2012). 16 All instrumented knee joint drawer tests were performed by a single licensed physical therapist (intrarater reliability [intraclass correlation coefficient] = 0.92). 27 Analog data (both arthrometer and DVRT) were collected at 100 Hz.…”

Finite Element Model of the Knee for Investigation of Injury Mechanisms: Development and Validation

“…The high frequency of ACL injury (more than 120,000 in the United States annually [3]), associated cost, and subsequent long-term disability have generated significant interest in the investigation of ACL injury mechanisms. Extensive efforts have served to investigate knee biomechanics with a primary emphasis on the ACL utilizing ex vivo techniques [4][5][6][7][8][9][10][11], clinical studies, and in vivo evaluations [2,[12][13][14][15][16][17][18]. Although these controlled laboratory studies have substantially improved our understanding of knee biomechanics and injury, inherent limitations associated with the existing experimental methods make data interpretation and parametric analyses challenging.…”