ANALYSIS OF SKELETAL MOTION KINEMATICS FOR A KNEE MOVEMENT CYCLE (original) (raw)
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Knee Surgery, Sports Traumatology, Arthroscopy, 2012
Purpose The transepicondylar axis (TEA) has been used as a flexion axis of the knee and a reference of the rotational alignment of the femoral component. However, no study has showed dynamic normal knee kinematics employing TEA as the evaluation parameter throughout the full range of motion in vivo. The purpose of this study was to analyze dynamic kinematics of the normal knee through the full range of motion via the 3-dimensional to 2-dimensional registration technique employing TEA as the evaluation parameter. Methods Dynamic motion of the right knee was analyzed in 20 healthy volunteers (10 female, 10 male; mean age 37.2 years). Knee motion was observed as subjects squatted from standing with knee fully extended to maximum flexion. The following parameters were determined: (1) Anteroposterior translations of the medial and lateral ends of the TEA; and (2) changes in the angle of the TEA on the tibial axial plane (rotation angle). Results The medial end of the TEA demonstrated anterior translation (3.6 ± 3.0 mm) from full extension to 30°fl exion and demonstrated posterior translation (18.1 ± 3.7 mm) after 30°, while the lateral end of the TEA demonstrated consistent posterior translation (31.1 ± 7.3 mm) throughout knee flexion. All subjects exhibited femoral external rotation (16.9 ± 6.2°) relative to the tibia throughout knee flexion. Conclusion Compared to previously used parameters, the TEA showed bicondylar posterior translation from early flexion phase. These results provide control data for dynamic kinematic analyses of pathologic knees in the future and will be useful in the design of total knee prostheses.
Effect of skin movement on the analysis of skeletal knee joint motion during running
Journal of Biomechanics, 1997
It is not known how well skin markers represent the skeletal knee joint motion during running. Hence, the purpose of this investigation was to compare the skin marker derived tibiofemoral motion with the skeletal tibiofemoral motion during running. In addition to skin markers attached to the shank and thigh, triads of reflective markers were attached to bone pins inserted into the tibia and femur. Three-dimensional kinematics of the stance phase of five running trials were recorded for three subjects using high-speed tine cameras (200 Hz). The knee motion was expressed in terms of Cardan angles calculated from both the external and skeletal markers. Good agreement was present between the skin and bone marker based knee flexion/extension. For abductiomadduction and internal/external knee rotation, the difference between skeletal and external motion was large compared to the amplitude of these motions. Average errors relative to the range of motion during running stance were 21% for flexion/extension, 63% for internal/external rotation, and 70% for abduction/adduction. The errors were highly subject dependent preventing the realization of a successful correction algorithm. It was concluded that knee rotations other than flexion/extension may be affected with substantial errors when using skin markers. i' 1997 Elsevier Science Ltd
Estimation of the Moving Joint Axis in the Knee Joint by Motion Analysis Data
Isbs Conference Proceedings Archive, 2007
It is essential to use individually parameterized models for the knee joint as well as for the patellofemoral joint while analyzing the correlations between external and internal loads and the efficiency of specific training exercises for the lower extremities. A new approach to estimate the moving joint axis within the knee joint using motion analysis data was evaluated. The results of this single case study show that this approach might offer a possibility to parameterize an individualized knee joint model without using MRI scans.
Identification of Methods for Estimating Knee Rotation Axis
The Quantified Motion Analysis (QMA) has become in recent years a clinical examination whose understanding and improvement are being developed. Based on a three-dimensional projection of the body segments, the QMA must define these segments and their means of union, the axes and centers of articular rotation. Two main techniques exist: predictive estimation techniques and functional techniques which use a calibration movement to estimate the axes and centers of rotation. These latter techniques, known as functional, seem to show superiority in terms of reproducibility of the estimate of the axis of rotation of the knee, but no consensus exists. The same applies to the calibration movements used.
Skin movement artefact assessment and compensation in the estimation of knee-joint kinematics
Journal of Biomechanics, 1998
In three dimensional (3-D) human movement analysis using close-range photogrammetry, surface marker clusters deform and rigidly move relative to the underlying bone. This introduces an important artefact (skin movement artefact) which propagates to bone position and orientation and joint kinematics estimates. This occurs to the extent that those joint attitude components that undergo small variations result in totally unreliable values. This paper presents an experimental and analytical procedure, to be included in a subject-specific movement analysis protocol, which allows for the assessment of skin movement artefacts and, based on this knowledge, for their compensation. The effectiveness of this procedure was verified with reference to knee-joint kinematics and to the artefacts caused by the hip movements on markers located on the thigh surface. Quantitative validation was achieved through experimental paradigms whereby prior reliable information on the target joint kinematics was available. When position and orientation of bones were determined during the execution of a motor task, using a least-squares optimal estimator, but the rigid artefactual marker cluster movement was not dealt with, then knee joint translations and rotations were affected by root mean square errors (r.m.s.) up to 14 mm and 6°, respectively. When the rigid artefactual movement was also compensated for, then r.m.s errors were reduced to less than 4 mm and 3°, respectively. In addition, errors originally strongly correlated with hip rotations, after compensation, lost this correlation.
In skin-marker based motion analysis, knee translation measurement is highly dependent on a pre-selected reference point (functional center) on each segment determined by the location of anatomical landmarks. However, the placement of skin markers on palpable anatomical landmarks (i.e. femoral epicondyles) has limited reproducibility. Thus, it produces large variances in knee translation measurement among different subjects, as well as across studies. In order improve the repeatability of knee translation measurement, in this study an optimization method was introduced, by which the femoral functional center was numerically determined. At that point the knee anteroposterior translation during the stance phase of walking was minimized. This new method was tested on 30 healthy subjects during walking in gait lab with motion capture system. Using this new method, the impact of skin marker position (at anatomical landmarks) on the knee translation measurement has been minimized. In addi...
Three-dimensional kinematics of the human knee during walking
Journal of Biomechanics, 1992
Three-dimensional kinematics of the tibiofemoral joint were studied during normal walking. Target markers were fixed to tibia and femur by means of intra-cortical traction pins. Radiographs of the lower limb were obtained to compute the position of the target markers relative to internal anatomical structures. High-speed tine cameras were used to measure threedimensional coordinates of the target markers in five subjects walking at a speed of 1.2 m s -'. Relative motion between tibia and femur was resolved according to a joint coordinate system (JCS). The measurements have identified that substantial angular and linear motions occur about and along each of the JCS axes during walking. The results do not, however, support the traditional view that the so-called 'screw home' mechanism of the knee joint operates during gait. A planar model of the knee joint to characterize the knee extensor mechanism. 1. Biomechanics 22, l-10.
Motion analysis of human cadaver knee-joints using anatomical coordinate system
Biomechanica Hungarica, 2010
Large standard deviation can be observed during the analysis of the kinematical functions which describe the motion of the knee-joint. Screening the previous large number of published results concerning to the knee motion it seemed that they are scattered, therefore it can be regarded as unreliably. In our experiments anatomical coordinate system recommended by VAKHUM project was used in favor to reduce standard deviation. Setting up the anatomical coordinate system in its special anatomical points are very uncertain. A protocol was settled for the orientation of the anatomical points and for the anatomical coordinate system. Experiments were performed on fi ve cadaver knees using the new protocol. The measurements were analyzed which has proved that the method offers a better accuracy.
Dynamic Activity Dependence of In Vivo Normal Knee Kinematics
Dynamic knee kinematics were analyzed for normal knees in three activities, including two different types of maximum knee flexion. Continuous X-ray images of kneel, squat, and stair climb motions were taken using a large flat panel detector. CT-derived bone models were used for model registration-based 3D kinematic measurement. Three-dimensional joint kinematics and contact locations were determined using three methods: bone-fixed coordinate systems, interrogation of CT-based bone model surfaces, and interrogation of MR-based articular cartilage model surfaces. The femur exhibited gradual external rotation throughout the flexion range. Tibiofemoral contact exhibited external rotation, with contact locations translating posterior while maintaining 158 to 208 external rotation from 208 to 808 of flexion. From 808 to maximum flexion, contact locations showed a medial pivot pattern. Kinematics based on bone-fixed coordinate systems differed from kinematics based on interrogation of CT and MR surfaces. Knee kinematics varied significantly by activity, especially in deep flexion. No posterior subluxation occurred for either femoral condyle in maximum knee flexion. Normal knees accommodate a range of motions during various activities while maintaining geometric joint congruency.