Peter S. Walker

Gokce Yildirim9
Sally Arno4
Jon Sussman-Fort3
Gregg R Klein3
Cheongeun Oh2
9Gokce Yildirim
4Sally Arno
3Jon Sussman-Fort
3Gregg R Klein
2Cheongeun Oh
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The aim was to determine the contact locations in the knee in a simulation of a deep squatting position, for both neutral and after tibial rotation. A rig was constructed to load the knee under quadriceps action at flexion angles from 135 to 155 degrees flexion, with a mechanism for rotating the tibia internally or externally. Fiducial points on each bone(More)
The objective was to develop a simple, rapid, and low-cost method for evaluating proposed new total knee arthroplasty (TKA) models and then to evaluate 3 different TKA models with different kinematic characteristics. A "desktop" knee testing rig was used to apply forces and moments over a full flexion range, representing a spectrum of positions and(More)
We constructed a crouching machine to study the motion of the knee joint, in which a motor was used to wind the quadriceps tendon so as to move the knee from high flexion to extension and back into flexion, while springs simulated hamstrings forces. Seven human cadaveric knees were tested intact and then after anterior cruciate ligament (ACL) resection.(More)
Maximum flexion-or impingement angle-is defined as the angle of flexion when the posterior femoral cortex impacts the posterior edge of the tibial insert. We examined the effects of femoral component placement on the femur, the slope angle of the tibial component, the location of the femoral-tibial contact point, and the amount of internal or external(More)
The kinematics of a mobile bearing knee, which allowed +/-20 degrees of rotation and 4.5 mm of anteroposterior translation, was measured for ascending and descending a step, deep-knee bend, normal walking, and twisting. A fluoroscopic technique was used, analyzed by 2 different methods. The rotations and displacements during the activities were similar to(More)
Mechanical evaluation of total knees is frequently required for aspects such as wear, strength, kinematics, contact areas, and force transmission. In order to carry out such tests, we developed a crouching simulator, based on the Oxford-type machine, with novel features including a synthetic knee including ligaments. The instrumentation and data processing(More)
The purpose of this study was to determine if a horizontal cleavage lesion (HCL) of the posterior horn of the medial meniscus would result in changes to tibiofemoral contact mechanics, as measured by peak contact pressure and contact area, which can lead to cartilage degeneration. To study this, 10 cadaveric knees were tested in a rig where forces were(More)
We studied the combined role of the medial meniscus in distributing load and providing stability. Ten normal knees were loaded in combinations of compressive and shear loading as the knee was flexed over a full range. A digital camera tracked the motion, from which femoral-tibial contacts were determined by computer modelling. Load transmission was(More)
The goal of this study was to determine knee motions in specimens under combined input forces over a full range of flexion, so that the various flexion angles and loading combinations encountered in functional conditions would be contained. The purpose was that the data would act as a benchmark for the evaluation of TKR designs using the same testing(More)