6R Instrumented Spatial Linkages for Anatomical Joint Motion Measurement—Part 2: Calibration

1992 ◽  
Vol 114 (1) ◽  
pp. 101-110 ◽  
Author(s):  
S. J. Kirstukas ◽  
J. L. Lewis ◽  
A. G. Erdman
Keyword(s):  
Measuring System ◽  
Joint Motion ◽  
Electrical Parameters ◽  
Knee Motion ◽  
Anatomical Position ◽  
Calibration Algorithm ◽  
Calibration Device ◽  
Spatial Linkages ◽  
Six Degree Of Freedom ◽  
Interdependent Relationships

The six-revolute-joint instrumented spatial linkage (6R ISL) is often the measurement system of choice for monitoring motion of anatomical joints. However, due to tolerances of the linkage parameters, the system may not be as accurate as desired. A calibration algorithm and associated calibration device have been developed to refine the initial measurements of the ISL’s mechanical and electrical parameters so that the measurement of six-degree-of-freedom motion will be most accurate within the workspace of the anatomical joint. The algorithm adjusts the magnitudes of selected linkage parameters to reduce the squared differences between the six known and calculated anatomical position parameters at all the calibration positions. Weighting is permitted so as to obtain a linkage parameter set that is specialized for measuring certain anatomical position parameters. Output of the algorithm includes estimates of the measuring system accuracy. For a particular knee-motion-measuring ISL and calibration device, several interdependent design parameter relationships have been identified. These interdependent relationships are due to the configuration of the ISL and calibration device, the number of calibration positions, and the limited resolution of the devices that monitor the position of the linkage joints. It is shown that if interdependence is not eliminated, then the resulting ISL parameter set will not be accurate in measuring motion outside of the calibration positions, even though these positions are within the ISL workspace.

6R Instrumented Spatial Linkages for Anatomical Joint Motion Measurement—Part 1: Design

1992 ◽  
Vol 114 (1) ◽  
pp. 92-100 ◽  
Author(s):  
S. J. Kirstukas ◽  
J. L. Lewis ◽  
A. G. Erdman
Keyword(s):  
Numerical Methods ◽  
Design Process ◽  
Joint Motion ◽  
Calibration Technique ◽  
Knee Motion ◽  
Motion Measurement ◽  
Experimental Apparatus ◽  
The Subject ◽  
Spatial Linkages ◽  
Six Degree Of Freedom

Six-revolute-joint instrumented spatial linkages (6R ISLs) have become often-used devices to measure the complete six-degree-of-freedom motion of anatomical joints. Accuracy of motion measurement depends on ISL design and calibration technique. In this paper, a design process is outlined that uses computer graphics and numerical methods as aids in developing 6R ISLs that (i) physically assemble within the desired range of motion of the joint; (ii) do not collide with either the experimental apparatus or the subject joint; (iii) avoid singular linkage configurations that can cause forces to be applied to the joint; and (iv) measure selected anatomical motions most accurately. It is found that a certain subgroup of 6R linkages are suitable for accurate measurement of specific motions, and can be the basis for new ISL designs. General guidelines are developed that can assist in the generation of unique linkage designs for different anatomical joints. The design process is demonstrated in the creation of an ISL to measure knee motion.

Effect of Dynamic Changes in Anterior Cruciate Ligament In Situ Graft Force on the Biological Healing Response of the Graft-Tunnel Interface

2018 ◽  
Vol 46 (4) ◽  
pp. 915-923 ◽  
Author(s):  
Richard Ma ◽  
Michael Schär ◽  
Tina Chen ◽  
Marco Sisto ◽  
Joseph Nguyen ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Acl Reconstruction ◽  
Cruciate Ligament ◽  
Male Rats ◽  
Joint Motion ◽  
Dynamic Changes ◽  
Knee Motion ◽  
Acl Graft ◽  
Anterior Cruciate

Background: Anterior cruciate ligament (ACL) grafts that are placed for reconstruction are subject to complex forces. Current “anatomic” ACL reconstruction techniques may result in greater in situ graft forces. The biological effect of changing magnitudes of ACL graft force on graft-tunnel osseointegration is not well understood. Purpose: The research objective is to determine how mechanical force on the ACL graft during knee motion affects tendon healing in the tunnel. Study Design: Controlled laboratory study. Methods: Male rats (N = 120) underwent unilateral ACL reconstruction with a soft tissue flexor tendon autograft. ACL graft force was modulated by different femoral tunnel positions at the time of surgery to create different graft force patterns with knee motion. External fixators were used to eliminate graft load during cage activity. A custom knee flexion device was used to deliver graft load through controlled daily knee motion. Graft-tunnel healing was then assessed via biomechanical, micro–computed tomography, and histological analyses. Results: ACL graft-tunnel healing was sensitive to dynamic changes in graft forces with postoperative knee motion. High ACL graft force with joint motion resulted in early inferior ACL graft load to failure as compared with knees that had low-force ACL grafts and joint motion and knees that were immobilized (mean ± SD: 5.50 ± 2.30 N vs 9.91 ± 3.54 N [ P = .013] and 10.90 ± 2.8 N [ P = .001], respectively). Greater femoral bone volume fraction was seen in immobilized knees and knees with low-force ACL grafts when compared with high-force ACL grafts at 3 and 6 weeks. Conclusion: The authors were able to demonstrate that ACL graft-tunnel incorporation is sensitive to dynamic changes in ACL graft force with joint motion. Early high forces on the ACL graft appear to impair graft-tunnel osseointegration. Clinical Relevance: Current “anatomic” techniques of ACL reconstruction may result in greater graft excursion and force with knee motion. Our results suggest that the postoperative rehabilitation regimen may need to be modified during the early phase of healing to protect the reconstruction.

Design and Evaluation of a New General-Purpose Device for Calibrating Instrumented Spatial Linkages

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Joshua A. Nordquist ◽  
M. L. Hull
Keyword(s):  
Measurement Error ◽  
Gold Standard ◽  
Measurement Errors ◽  
Mean Squared Error ◽  
General Purpose ◽  
New Method ◽  
Coordinate Measurement ◽  
Calibration Device ◽  
Spatial Linkages ◽  
The Many

Because instrumented spatial linkages (ISLs) have been commonly used in measuring joint rotations and must be calibrated before using the device in confidence, a calibration device design and associated method for quantifying calibration device error would be useful. The objectives of the work reported by this paper were to (1) design an ISL calibration device and demonstrate the design for a specific application, (2) describe a new method for calibrating the device that minimizes measurement error, and (3) quantify measurement error of the device using the new method. Relative translations and orientations of the device were calculated via a series of transformation matrices containing inherent fixed and variable parameters. These translations and orientations were verified with a coordinate measurement machine, which served as a gold standard. Inherent fixed parameters of the device were optimized to minimize measurement error. After parameter optimization, accuracy was determined. The root mean squared error (RMSE) was 0.175 deg for orientation and 0.587 mm for position. All RMSE values were less than 0.8% of their respective full-scale ranges. These errors are comparable to published measurement errors of ISLs for positions and lower by at least a factor of 2 for orientations. These errors are in spite of the many steps taken in design and manufacturing to achieve high accuracy. Because it is challenging to achieve the accuracy required for a custom calibration device to serve as a viable gold standard, it is important to verify that a calibration device provides sufficient precision to calibrate an ISL.

Development of a Measuring System for the Measurement of Motions Errors of a Linear Stage

2004 ◽  
Author(s):  
Wen-Yuh Jywe ◽  
Chien-Hung Liu ◽  
Sheng-Chung Tzeng ◽  
Po Chou ◽  
Chu-Wei Lin
Keyword(s):  
Measuring Method ◽  
Degree Of Freedom ◽  
Angular Error ◽  
Measuring System ◽  
Linear Stage ◽  
Process Verification ◽  
Error Components ◽  
Dual Beam ◽  
Six Degree Of Freedom ◽  
Straightness Error

A high precision six-degree-of-freedom measuring system is developed in this paper for the motion measurement of a linear stage. It integrates a miniature dual-beam fiber coupled laser interferometer with the multiple optical paths and quadrant detectors to be capable of measuring six-degree-of-freedom motion errors. The proposed measuring method provides rapid performance, simplicity of setup, and pre-process verification of a linear positioning stage. The experimental setup and algorithm for the error verification are presented in the paper. The measuring range of the proposed measuring system is ±40μm for straightness and 40 arc sec for pitch, roll and yaw. Within the range of ±40μm and 40 arc sec, it has been found that the system’s resolution and accuracy of measuring straightness error components are about 0.04 μm and ±0.06 μm, respectively. The resolution and accuracy of measuring pitch and yaw angular error components are about 0.06 arc sec and ±0.8 arc sec, respectively. The resolution and accuracy of measuring roll angular error are about 0.05 arc sec and ±0.07 arc sec, respectively.

Simultaneous In Vitro Measurement of Patellofemoral Kinematics and Forces

2004 ◽  
Vol 126 (3) ◽  
pp. 351-356 ◽  
Author(s):  
Amy B. Zavatsky ◽  
Paul T. Oppold ◽  
Andrew J. Price
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Motion ◽  
Leg Extension ◽  
Total Knee ◽  
Quadriceps Force ◽  
The Individual ◽  
Six Degree Of Freedom ◽  
Tibiofemoral Kinematics ◽  
Patellofemoral Kinematics

This study involved the development and testing of a system for the simultaneous in vitro measurement of tibiofemoral kinematics and patellofemoral kinematics and forces. Knee motion was tracked using a Vicon 370, and patellofemoral force was measured using a six degree-of-freedom transducer based on the design of Singerman et al. Using this system, twelve knee specimens were tested in supine leg extension under a simulated quadriceps force. The comprehensive set of results corresponds well to the individual results of previous studies. The measurement system will be of value in assessing the effects of total knee arthroplasty on patellar function.

scholarly journals Isolating the Energetic and Mechanical Consequences of Imposed Reductions in Ankle and Knee Flexion during Gait.

2021 ◽  
Author(s):  
Emily McCain ◽  
Theresa Libera ◽  
Matthew Berno ◽  
Gregory Sawicki ◽  
Katherine Saul ◽  
...  
Keyword(s):  
Metabolic Cost ◽  
Relative Increase ◽  
Joint Motion ◽  
Knee Motion ◽  
Ankle Motion ◽  
Gait Characteristics ◽  
Joint Range Of Motion ◽  
3D Printed ◽  
Ankle Function ◽  
Joint Range

Abstract Background: Weakness of ankle and knee musculature following injury or disorder results in reduced joint motion associated with metabolically expensive gait compensations to enable limb support and advancement. However, neuromechanical coupling between the ankle and knee make it difficult to discern independent roles of these restrictions in joint motion on compensatory mechanics and metabolic penalties.Methods: We sought to determine relative impacts of ankle and knee impairment on compensatory gait strategies and energetic outcomes using an unimpaired cohort (N=15) with imposed unilateral joint range of motion restrictions as a surrogate for reduced motion resulting from gait pathology. Participants walked on a dual-belt instrumented treadmill at 0.8 m s-1 using a 3D printed ankle stay and a knee brace to systematically limit ankle motion (restricted-ank), knee motion (restricted-knee), and ankle and knee motion (restricted-a+k) simultaneously. In addition, participants walked without any ankle or knee bracing (control) and with knee bracing worn but unrestricted (braced).Results: When ankle motion was restricted (restricted-ank, restricted-a+k) we observed decreased peak propulsion relative to the braced condition on the restricted limb. Reduced knee motion (restricted-knee, restricted-a+k) increased restricted limb circumduction relative to the restricted-ank condition through ipsilateral hip hiking. Interestingly, restricted limb average positive hip power increased in the restricted-ank condition but decreased in the restricted-a+k and restricted-knee conditions, suggesting that locking the knee impeded hip compensation. As expected, reduced ankle motion, either without (restricted-ank) or in addition to knee restriction (restricted-a+k) yielded significant increase in net metabolic rate when compared with the braced condition. Furthermore, the relative increase in metabolic cost was significantly larger with restricted-a+k when compared to restricted-knee condition.Conclusions: Our methods allowed for the reproduction of asymmetric gait characteristics including reduced propulsive symmetry and increased circumduction. The metabolic consequences bolster the potential energetic benefit of targeting ankle function during rehabilitation.

Joint Models, Degrees of Freedom, and Anatomical Motion Measurement

1983 ◽  
Vol 105 (1) ◽  
pp. 55-62 ◽  
Author(s):  
G. L. Kinzel ◽  
L. J. Gutkowski
Keyword(s):  
Measurement Technique ◽  
Degrees Of Freedom ◽  
Measurement Techniques ◽  
Kinematic Model ◽  
Joint Motion ◽  
Review Of The Literature ◽  
Joint Models ◽  
Motion Measurement ◽  
Six Degrees Of Freedom ◽  
Six Degree Of Freedom

When the motion associated with an anatomical joint is to be measured, a kinematic model for the joint must first be established. The joint model will have from one to six degrees of freedom, and both the measurement technique and the means used to describe the motion will be influenced by the model and its degrees of freedom. This paper discusses the modeling and measurement of anatomical joint motion from a kinematics viewpoint. A review of the literature pertaining to measurement techniques, kinematic assumptions, and motion descriptions for anatomical joint motion is presented. One, two, three and six degree-of-freedom models for various anatomical joints have appeared in the literature, and the applicability of these models is compared and discussed.

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