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Zoe Hudson - One of the best experts on this subject based on the ideXlab platform.
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Reliability testing of the patellofemoral Joint Reaction Force (PFJRF) measurement during double-legged squatting in healthy subjects: a pilot study.
Journal of bodywork and movement therapies, 2012Co-Authors: Javid Mostamand, Dan L. Bader, Zoe HudsonAbstract:Summary Introduction Anterior knee pain or patellofemoral pain syndrome (PFPS) is supposed to be related to patellofemoral Joint Reaction Forces (PFJRF). Measuring these Forces may therefore provide reliable evidence for conservative treatments to correct probable malalignment in subjects with PFPS. The aim of the present study was to examine the reliability of PFJRF measurements during double-legged squatting in healthy subjects. Methods Using a motion analysis system and one Forceplate, PFJRF of 10 healthy subjects were assessed during double-legged squatting. Data were collected from superficial markers taped to selected landmarks. This procedure was performed on the right knees, at three different knee flexion angles of 30, 45 and 60° during three separate double-legged squats. Subjects were then requested to repeat this test procedure on two separate test sessions at different occasions. The PFJRF was calculated using a biomechanical model of the patellofemoral Joint. Results The data reveal an increase in PFJRF values (from mean, SD of 425.2, 35.5N to 1075.4, 70.1N)with an increase in the tibiofemoral Joint angle during double-legged squatting. The CV (coefficient of variation) values during within and between session tests, revealed the high repeatability and reproducibility of PFJRF measurements, while the ICC (intra class correlation coefficient) values showed the low reliability of these measurements. Conclusion The low reliability of PFJRF measurements suggests that the PFJRF measurement during double-legged squatting should be performed with caution with improving the method of kinetic measurement of the patellofemoral Joint in healthy subjects.
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Does leg predomination affect the measurement of patellofemoral Joint Reaction Force (PFJRF) during single leg squatting?: a reliability study
Journal of bodywork and movement therapies, 2012Co-Authors: Javid Mostamand, Dan L. Bader, Zoe HudsonAbstract:Summary Introduction Although measuring patellofemoral Joint Reaction Forces (PFJRF) may provide reliable evidence for conservative treatments to correct probable malalignment in subjects with patellofemoral pain syndrome (PFPS), it may be necessary to determine whether the inherent properties of the dominant leg influences the reliability of measuring PFJRF. The aim of the present study was to examine the effect of leg predomination on reliability testing of the PFJRF measurement during single leg squatting in healthy subjects. Methods Using a motion analysis system and one Force plate, PFJRF of 10 healthy subjects with a right dominant leg was assessed during single leg squatting. Data was collected from superficial markers taped to selected landmarks. This procedure was performed on the both right and left legs, during three separate single leg squats from a neutral position to a depth of approximately 30° of knee flexion. Subjects were then asked to repeat the test procedure after a minimum of a week’s interval. The PFJRF was calculated using a biomechanical model of the patellofemoral Joint. Results There was significant difference between the PFJRF mean values of paired test of right (mean, SD of 1887.7, 325.1 N) and left knees (mean, SD of 2022.6, 270.5 N) ( p Conclusion The high reliability of PFJRF measurements on both dominant and non-dominant legs of healthy subjects suggests that the PFJRF measurement would not be influenced by the leg predomination during single leg squatting.
John C. Elfar - One of the best experts on this subject based on the ideXlab platform.
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Alterations in tibiotalar Joint Reaction Force following syndesmotic injury are restored with static syndesmotic fixation.
Clinical biomechanics (Bristol Avon), 2019Co-Authors: Meghan Kelly, Daniel Vasconcellos, Walid Osman, Noorullah Masqoodi, Xavier Fowler, John C. Elfar, Mark Olles, Adolph S. Flemister, John KetzAbstract:Abstract Introduction Syndesmotic injury alters Joint mechanics, which may fail to be restored unless an anatomic reduction is obtained. Methods A minimally invasive method of measuring Joint Forces was utilized that does not require significant dissection or intraarticular placement of sensory instruments. Steinmann pins were placed in the tibia and talus of eight fresh-frozen human cadaveric lower extremities and a baseline Joint Reaction Force was determined. A syndesmotic injury was created and reduction (anatomic and anterior malreduction) performed with one or two quadricortical screws and Joint Reaction Forces were measured after the injury and subsequent repairs. Findings Baseline mean tibiotalar Joint Reaction Force was 31.4 (SD 7.3 N) and syndesmotic injury resulted in a 35% decrease (mean 20.3, SD 8.4 N, p Interpretation The present study demonstrates that syndesmotic injury decreases Joint Reaction Force within the tibiotalar Joint, suggesting ankle Joint instability. Tibiotalar Force was restored with anatomic reduction with either a 1 or 2 quadricortical syndesmotic screws. Furthermore, anterior malreduction restored Joint Reaction Force to levels similar to those observed at baseline and with anatomic reduction. Level of Evidence: Level V: biomechanical/cadaver study.
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Radiographic Validation of a Non-invasive Method of Measuring Hip Joint Reaction Force using a Cartilage Relaxation Technique
Orthopaedic Journal of Sports Medicine, 2017Co-Authors: Joseph C Schaffer, Daniel Vasconcellos, John C. Elfar, Mark Olles, Noorullah Maqsoodi, Nathan Kaplan, Brian D. GiordanoAbstract:Objectives: Joint Reaction Forces (JRF) and contact pressures are classically measured using destructive techniques which require dissection and interposition of materials into the Joint, fundamentally altering the normal Joint mechanics. Without an alternate method available, modern hip JRF biomechanical studies involve this stripping of periarticular tissues, potentially sacrificing accurate measurements. As hip arthroscopy is increasingly employed for minimally invasive treatment of hip pathology, there may be a need for minimally invasive biomechanical measurement techniques that reflect JRF more accurately. This study’s objectives were to demonstrate that a non-invasive, non-destructive technique for measuring JRF was feasible in the hip and to validate this concept using simultaneous radiographic imaging. Methods: Twenty fresh frozen male human cadaver hemipelves were instrumented with a custom-made retrograde intramedullary nail-plate construct in the femur and an iliac-crest locking plate. These otherwise fully-intact specimens were rigidly mounted for tensile testing (Instron Model 1122). With the hip in the neutral position, the Joint was distracted 5mm along the axis of the femoral shaft at a rate of 0.4mm/s, while simultaneously measuring the Force required for distraction. Force-displacement curves generated allowed the best-fit polynomial to be found with resulting revelation of the native state JRF. Next, the Joint capsule was vented under fluoroscopic control using an 18 gauge spinal needle and distraction was repeated from the native state with fluoroscopic images captured at 0.5mm increments. All testing was repeated three times, and two specimens were excluded for severe osteoarthritis (<2mm Joint-space). Results: Force-displacement curves demonstrated an initially steep but decreasing (concave-down) slope, followed by an inflection point, a linear region and then a relatively non-linear increasing (concave-up) slope with further distraction. High reproducibility between repeated measurements was found within specimens and the average native resting JRF was 115.1 N (n=18). Capsular venting decreased JRF by 16.3 N (mean post-venting=98.8 N). Under fluoroscopy, air arthrograms confirmed cartilage relaxation consistently at the measured Force-distraction infection point. Conclusion: This study describes and validates a reproducible method of measuring hip JRF that preserves all periarticular stabilizing soft tissue structures. This is the first study in any Joint to correlate Force-distraction data with fluoroscopic images, confirming the method’s central premise: That JRF is equal to the measured Force-distraction curve inflection point. This may be ideally suited for application in biomechanical studies of minimally invasive arthroscopic hip surgery.
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Noninvasive Measurement of Normal Foot and Ankle Joint Reaction Force
Foot & Ankle Orthopaedics, 2016Co-Authors: Noorullah Maqsoodi, Daniel Vasconcellos, Walid Osman, Xavier Fowler, John C. Elfar, Mark Olles, John Ketz, Adolph S. FlemisterAbstract:Category:Basic Sciences/BiologicsIntroduction/Purpose:Various biomechanical studies have examined pressure changes across the foot and ankle Joints. However, most of these studies disrupted the capsuloligamentous complex surrounding the Joint to insert pressure sensors, compromising the integrity of the natural Joint structure and the accuracy of biomechanical assessments. This is the first noninvasive study to report measurement of natural Joint Reaction Forces (JRF) across the foot and ankle while preserving all soft tissue structures. Since articular surfaces experience equal and opposing compression Forces, we aimed to evaluate the distraction Force needed to overcome these compression Forces.Methods:Ten fresh-frozen cadavers of the lower extremity were obtained that were disarticulated at the knee Joint. Steinmann pins were percutaneously placed across the distal tibia, and the center of the talus, navicular, cuboid, and calcaneus while preserving all surrounding soft tissues. A custom fixation devic...
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A Novel Method for Measurement of Ankle Joint Reaction Force and Response to Syndesmotic Injury
Foot & Ankle Orthopaedics, 2016Co-Authors: Meghan Kelly, Daniel Vasconcellos, Walid Osman, Xavier Fowler, John C. Elfar, Mark Olles, Noorullah Maqsoodi, John KetzAbstract:Category: Ankle. Introduction/Purpose: Increasing evidence has suggested that alterations in Joint mechanics results in articular pathology. Previous studies demonstrated noninvasive measurements of Joint reactive Forces (JRF) can be performed reliably without destruction of the peri-articular soft tissue in medium and small size Joints of the upper extremity. This study presents a novel, noninvasive measurement of the JRF to investigate the normal and the effects of a syndesmotic injury. The JRF of the tibiotalar Joint was also evaluated following anatomic reduction with fixation and malreduction of the syndesmosis. Methods: Eight fresh-frozen human cadaveric lower extremity limbs were obtained disarticulated above the knee. A distraction Force was applied across the tibio-talar Joint to determine the baseline (normal) ankle Force displacement curve. Next, a syndesmotic injury was created by releasing the interosseous syndesmotic ligaments, the transverse tibiofibular ligament and the anterior and posterior tibiofibular ligaments. Prior to sectioning, two drill holes were placed across the Joint and tapped to ensure anatomic reduction. JRF were measured using a quadricortical technique with a single or double screw configuration. The syndesmosis was malreduced by anteriorly displacing the fibula 5 mm. After each step, the resultant JRFs were determined using a distraction Force across the tibiotalar Joint. Results: Force displacement curves obtained from multiple measurements from each specimen with a mean ankle JRF of 31.4 + 2.6 N. Syndesmotic injury resulted in a 35% decrease in tibiotalar JRF (20.3 + 3.0 N, p=0.002). Fixation of the injury using one syndesmotic screw resulted in significant increase in JRF compared to injury JRF (28.7 + 1.4 N, p=0.02). Syndesmotic fixation with 2 screws also demonstrated a trend towards restoration of tibiotalar JRF (28.3 + 2.2 N, p=0.06). There was no statistical difference between fixation of one versus two syndesmotic screws. The JRF for the malreduced syndesmosis was 31.5 + 1.8 N (p=0.03,) resulting in increased Forces approaching the baseline JRF. Conclusion: This study demonstrates a non-destructive model by which to measure Joint reactive Forces (JRF) across the tibiotalar Joint and that these Forces are diminished as a result of a syndesmotic injury, suggesting Joint instability. Surgical stabilization with either 1 or 2 screws creates JRF that are similar to the normal JRF. Even with a malreduced syndesmosis, there appeared to be a JRF similar to baseline tibiotalar Joint Forces. However malreduction of the syndesmosis may alter the Joint dynamics of the ankle in ways that were not measured in this study.
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Distal radioulnar Joint Reaction Force following ulnar shortening: Diaphyseal osteotomy versus wafer resection
The Journal of hand surgery, 2015Co-Authors: Colin D. Canham, Mark Olles, Michael J. Schreck, Noorullah Maqsoodi, Susan Messing, John C. ElfarAbstract:Purpose To compare how ulnar diaphyseal shortening and wafer resection affect distal radioulnar Joint (DRUJ) Joint Reaction Force (JRF) using a nondestructive method of measurement. Our hypothesis was that ulnar shortening osteotomy would increase DRUJ JRF more than wafer resection. Methods Eight fresh-frozen human cadaveric upper limbs were obtained. Under fluoroscopic guidance, a threaded pin was inserted into the lateral radius orthogonal to the DRUJ and a second pin was placed in the medial ulna coaxial to the radial pin. Each limb was mounted onto a mechanical tensile testing machine and a distracting Force was applied across the DRUJ while Force and displacement were simultaneously measured. Data sets were entered into a computer and a polynomial was generated and solved to determine the JRF. This process was repeated after ulnar diaphyseal osteotomy, ulnar re-lengthening, and ulnar wafer resection. The JRF was compared among the 4 conditions. Results Average baseline DRUJ JRF for the 8 arms increased significantly after diaphyseal ulnar shortening osteotomy (7.2 vs 10.3 N). Average JRF after re-lengthening the ulna and wafer resection was 6.9 and 6.7 N, respectively. There were no differences in JRF among baseline, re-lengthened, and wafer resection conditions. Conclusions Distal radioulnar Joint JRF increased significantly after ulnar diaphyseal shortening osteotomy and did not increase after ulnar wafer resection. Clinical relevance Diaphyseal ulnar shortening osteotomy increases DRUJ JRF, which may lead to DRUJ arthrosis.
Thay Q. Lee - One of the best experts on this subject based on the ideXlab platform.
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Biomechanical effects of kneeling after total knee arthroplasty.
The Journal of bone and joint surgery. American volume, 2007Co-Authors: Kenneth J Wilkens, Long V. Duong, Michelle H. Mcgarry, William C. Kim, Thay Q. LeeAbstract:Background: Kneeling following total knee arthroplasty can be a difficult task, impairing the activities of patients to varying degrees. Little is known about the biomechanical effects of kneeling following total knee replacement. The objective of this study was to quantify the effects of kneeling on patellofemoral Joint contact areas and pressures, knee Joint Reaction Force, and patellar kinematics. Methods: Total knee arthroplasties were performed on eight fresh-frozen cadaveric knees, and they were tested with use of a custom knee jig, which permits the simulation of physiologic quadriceps loading as well as the application of an anterior Force to simulate kneeling. The knees were tested at flexion angles of 90°, 105°, 120°, and 135° with no anterior Force (mimicking a squatting position) and with an anterior Force application simulating double-stance kneeling and single-stance kneeling. Patellofemoral Joint contact areas and pressures were measured with pressure-sensitive film, and the knee Joint Reaction Force was measured with use of a six-degree-of-freedom load cell. Patellar kinematics were assessed with use of digital photographs tracking fixed markers on the patella. Results: Compared with the condition without kneeling, both single-stance and double-stance kneeling demonstrated significant increases in patellofemoral contact area (p < 0.05) and pressure at all flexion angles (p < 0.05), with the exception of double-stance kneeling at 135° of flexion. The resultant knee Joint -Reaction Force increased with kneeling at all flexion angles. The compressive component of this Force increased with kneeling for most conditions, while the lateral component of this Force decreased significantly (p < 0.05) with kneeling only at 90°, and the anterior component of this Force increased significantly at all knee flexion angles (p < 0.05). Overall, kneeling had minimal changes on patellar tilt, with significant changes in patellar tilt seen only with kneeling at 120° (p = 0.02 for double stance, and p = 0.03 for single stance). Conclusions: The findings of this study suggest that kneeling at a higher flexion angle (135°) after total knee arthroplasty has a smaller effect on patellofemoral Joint contact area and pressure than kneeling at lower flexion angles (≤120°). Clinical Relevance: These findings suggest that if greater than 120° of knee range of motion can be achieved following total knee arthroplasty, kneeling may be performed with less risk than was previously believed to be the case.
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A novel cadaveric model for anterior-inferior shoulder dislocation using forcible apprehension positioning.
Journal of rehabilitation research and development, 2003Co-Authors: Patrick J. Mcmahon, Bruce Y. Yang, Stephen Chow, Laura N. Sciaroni, Thay Q. LeeAbstract:A novel cadaveric model for anterior-inferior shoulder dislocation using forcible apprehension positioning is presented. This model simulates an in vivo mechanism and yields capsulolabral lesions. The scapulae of 14 cadaveric entire upper limbs (82 +/- 9 years, mean +/- standard deviation) were each rigidly fixed to a custom shoulder-testing device. A pneumatic system was used with pulleys and cables to simulate the rotator cuff and the deltoid muscles (anterior and middle portions). The glenohumeral Joint was then positioned in the apprehension position of abduction, external rotation, and horizontal abduction. A 6-degree-of-freedom load cell (Assurance Technologies, Garner, North Carolina) measured the Joint Reaction Force that was then resolved into three orthogonal components of compression Force, anteriorly directed Force, and superiorly directed Force. With the use of a thrust bearing, the humerus was moved along a rail with a servomotor-controlled system at 50 mm/s that resulted in horizontal abduction. Force that developed passively in the pectoralis major muscle was recorded with an independent uniaxial load cell. Each of the glenohumeral Joints dislocated anterior-inferior, six with avulsion of the capsulolabrum from the anterior-inferior glenoid bone and eight with capsulolabral stretching. Pectoralis major muscle Force as well as the Joint Reaction Force increased with horizontal abduction until dislocation. At dislocation, the magnitude of the pectoralis major muscle Force, 609.6 N +/- 65.2 N was similar to the compression Force, 569.6 N +/- 37.8 N. A cadaveric model yielded an anterior dislocation with a mechanism of forcible apprehension positioning when the appropriate shoulder muscles were simulated and a passive pectoralis major muscle was included. Capsulolabral lesions resulted, similar to those observed in vivo.
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Effects of anteroinferior capsulolabral incision and resection on glenohumeral Joint Reaction Force.
Journal of rehabilitation research and development, 2002Co-Authors: Patrick J. Mcmahon, Vance C. Eberly, Bruce Y. Yang, Thay Q. LeeAbstract:Successful outcome of a Bankart procedure depends on knowledge of the effects of capsulolabral lesions on Joint biomechanics. The Joint Reaction Force, through "concavity compression," is integral to glenohumeral stability. In this study, we applied loads to the tendons of the rotator cuff and deltoid (anterior and middle portions) of five cadaver upper limbs. The Joint Reaction Force was measured with a 6 degrees of freedom load cell for the intact condition and each of two test conditions: (1) incision and (2) partial resection of the anteroinferior capsulolabrum. We used analysis of variance to compare Joint Reaction Forces resolved into that which is directed perpendicular (compression Force), anterior, and superior to the glenoid. Compression Force for the two different capsulolabral lesions of the glenohumeral Joint was the same, 133 N +/- 13 N, a small 12% decrease compared to the intact condition (151 N +/- 13 N). This difference was not statistically significant. Results were similar for the components of the Joint Reaction Force directed anterior and superior. Joint Reaction Force was not meaningfully altered after anteroinferior capsulolabral lesions were simulated. Because glenohumeral Joint stability involves complex interplay of static and dynamic restraints, additional shoulder injuries may be necessary for the Joint Reaction Force to be abnormal.
Haluk Darendeliler - One of the best experts on this subject based on the ideXlab platform.
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THE EFFECT OF ACTIVATOR TREATMENT OF SKELETAL CLASS 2 MALOCCLUSIONS ON THE TEMPOROMANDIBULAR Joint Reaction Force
Turkish Journal of Orthodontics, 1998Co-Authors: Oktay Üner, Nilüfer Darendeliler, Haluk DarendelilerAbstract:ABSTRACT A change in the pattern of condylar loading might lead to an increase in the amount of condylar/mandibular growth. In this study, the effect of activator treatment of skeletal Class 2 malocclusions on the magnitude and direction of the temporomandibular Joint Reaction Force has been investigated. The treatment group for this study consisted of 12 patients, 8 girls and 4 boys, with an average age of 11.42 ± 0.29 years and skeletal age of 11.02 ± 0.29 years. An Andresen type activator was used for a mean period of 11 months. Electromyographic (EMG) activity of the masseter and anterior temporal muscles were measured and lateral cephalometric radiographs were taken at the beginning and at the end of the study. A two-dimensional model is described on the lateral cephalometric radiographs which uses the intregated EMG (IEMG) activity of the muscles and bite Force as the input data and a computer program has been developed to calculate the magnitude and direction of the temporomandibular Joint Reaction...
Javid Mostamand - One of the best experts on this subject based on the ideXlab platform.
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Reliability testing of the patellofemoral Joint Reaction Force (PFJRF) measurement during double-legged squatting in healthy subjects: a pilot study.
Journal of bodywork and movement therapies, 2012Co-Authors: Javid Mostamand, Dan L. Bader, Zoe HudsonAbstract:Summary Introduction Anterior knee pain or patellofemoral pain syndrome (PFPS) is supposed to be related to patellofemoral Joint Reaction Forces (PFJRF). Measuring these Forces may therefore provide reliable evidence for conservative treatments to correct probable malalignment in subjects with PFPS. The aim of the present study was to examine the reliability of PFJRF measurements during double-legged squatting in healthy subjects. Methods Using a motion analysis system and one Forceplate, PFJRF of 10 healthy subjects were assessed during double-legged squatting. Data were collected from superficial markers taped to selected landmarks. This procedure was performed on the right knees, at three different knee flexion angles of 30, 45 and 60° during three separate double-legged squats. Subjects were then requested to repeat this test procedure on two separate test sessions at different occasions. The PFJRF was calculated using a biomechanical model of the patellofemoral Joint. Results The data reveal an increase in PFJRF values (from mean, SD of 425.2, 35.5N to 1075.4, 70.1N)with an increase in the tibiofemoral Joint angle during double-legged squatting. The CV (coefficient of variation) values during within and between session tests, revealed the high repeatability and reproducibility of PFJRF measurements, while the ICC (intra class correlation coefficient) values showed the low reliability of these measurements. Conclusion The low reliability of PFJRF measurements suggests that the PFJRF measurement during double-legged squatting should be performed with caution with improving the method of kinetic measurement of the patellofemoral Joint in healthy subjects.
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Does leg predomination affect the measurement of patellofemoral Joint Reaction Force (PFJRF) during single leg squatting?: a reliability study
Journal of bodywork and movement therapies, 2012Co-Authors: Javid Mostamand, Dan L. Bader, Zoe HudsonAbstract:Summary Introduction Although measuring patellofemoral Joint Reaction Forces (PFJRF) may provide reliable evidence for conservative treatments to correct probable malalignment in subjects with patellofemoral pain syndrome (PFPS), it may be necessary to determine whether the inherent properties of the dominant leg influences the reliability of measuring PFJRF. The aim of the present study was to examine the effect of leg predomination on reliability testing of the PFJRF measurement during single leg squatting in healthy subjects. Methods Using a motion analysis system and one Force plate, PFJRF of 10 healthy subjects with a right dominant leg was assessed during single leg squatting. Data was collected from superficial markers taped to selected landmarks. This procedure was performed on the both right and left legs, during three separate single leg squats from a neutral position to a depth of approximately 30° of knee flexion. Subjects were then asked to repeat the test procedure after a minimum of a week’s interval. The PFJRF was calculated using a biomechanical model of the patellofemoral Joint. Results There was significant difference between the PFJRF mean values of paired test of right (mean, SD of 1887.7, 325.1 N) and left knees (mean, SD of 2022.6, 270.5 N) ( p Conclusion The high reliability of PFJRF measurements on both dominant and non-dominant legs of healthy subjects suggests that the PFJRF measurement would not be influenced by the leg predomination during single leg squatting.
