scholarly journals Knee Joint Rotation Axis Is More Laterally Rotated and Valgus Than We Previously Thought

2021 ◽  
Author(s):  
Liwen Zheng ◽  
Deye Song ◽  
Yongheng Luo ◽  
Wanchun Wang ◽  
Xinzhan Mao ◽  
...  
Keyword(s):  
Knee Joint ◽  
Rotation Axis ◽  
Knee Prosthesis ◽  
Research Result ◽  
Three Dimensional ◽  
Contributing Factors ◽  
Chi Square ◽  
Transepicondylar Axis ◽  
Joint Rotation ◽  
Joint Axis

Abstract Background: Currently, the patient satisfaction rate after receiving TKA is around 80% to 90% and there is still room for further improvement. With the aim to provide reference for improving TKA surgery, stereophotogrammetry was used in this study to evaluate knee joint kinematics.Methods: Multiple MRI images of knee joints flexed at 0, 10, 20... to 100 degrees were scanned in bilateral knees of 45 asymptomatic adult volunteers. After three-dimensional alignment of the femur, the displacement and rotation angles of the tibia flexed at different angles were measured. Contributing factors were tested using One-way ANOVA and chi-square test in SPSS 24.Results: 1)No contributing factors was found to influence rotation axis; 2) Within the range of motion at 0-100° of flexion, the rotation axis exhibited no significant displacement relative to the femur. 3) On the horizontal plane, the lateral rotation angle of knee joint axis was 4.91°±1.84°(3°~7°) relative to transepicondylar axis (TEA) and 7.84°±2.09° relative to posterior condylar axis (PCA); on the coronal plane, the valgus angle of knee joint axis was 3.38°±0.82°(2.5°~5°) relative to tibial plateau, and 6.53°±0.91°(5°~8°) relative to the perpendicular line of the lower limb force line. Conclusion: No contributing factors were found, but the rotation axis of the knee joint is more laterally rotated and valgus than previously thought. These findings may explain the research result of some current literatures, and may provide theoretical rationale for further improvement of knee prosthesis design.

INTRA-SESSION RELIABILITY AND REPEATABILITY OF KNEE KINEMATICS IN SUBJECTS WITH ACL DEFICIENCY DURING STAIR ASCENT

2017 ◽  
Vol 17 (06) ◽  
pp. 1750092
Author(s):  
MARYAM HAJIZADEH ◽  
ALIREZA HASHEMI OSKOUEI ◽  
FARZAN GHALICHI ◽  
GISELA SOLE
Keyword(s):  
Knee Joint ◽  
Cruciate Ligament ◽  
Intraclass Correlation ◽  
Force Plate ◽  
Three Dimensional ◽  
Knee Kinematics ◽  
Compensatory Mechanisms ◽  
Joint Rotation ◽  
Stair Ascent ◽  
Acl Deficient

Analysis of knee kinematics and ground reaction forces (GRFs) is widely used to determine compensatory mechanisms of people with anterior cruciate ligament deficiency (ACLD). However, the practicality of the measurements is subject to their reliability during different trials. This study aims to determine the reliability and repeatability of knee joint rotations and GRFs in people with ACLD during stair ascent. Eight participants with unilateral ACL-deficient knees performed five trials of stair ascent with each leg. The movements were captured by VICON motion analysis system, and GRF components were recorded using force plate. Three-dimensional tibiofemoral joint rotations were calculated. Intraclass correlation coefficient (ICC), standard error of measurement (SEM) and coefficient of multiple correlation (CMC) were calculated ACL-deficient legs showed lower absolute reliability during swing ([Formula: see text]–6.4) than stance phase ([Formula: see text]–2.2) for knee joint rotations. Moderate to high average measure ICCs (0.59–0.98), relative reliability, were achieved for injured and uninjured sides. The results also demonstrated high repeatability for the knee joint rotation ([Formula: see text]–0.97) and GRF ([Formula: see text]–0.99). The outcomes of this study confirmed the consistency and repeatability of the knee joint rotations and GRFs in ACL-deficient subjects. Additionally, ACL-deficient legs exhibited similar levels of reliability and repeatability compared to contralateral legs.

scholarly journals Movement of the Distal Carpal Row During Narrowing and Widening of the Carpal Arch Width

2012 ◽  
Vol 134 (10) ◽  
Author(s):  
Joseph N. Gabra ◽  
Mathieu Domalain ◽  
Zong-Ming Li
Keyword(s):  
Carpal Tunnel ◽  
Rotation Axis ◽  
Carpal Tunnel Release ◽  
Three Dimensional ◽  
Joint Rotation ◽  
Ulnar Deviation ◽  
Motion Patterns ◽  
Arch Width ◽  
Complex Joint ◽  
Insight Into

Change in carpal arch width (CAW) is associated with wrist movement, carpal tunnel release, or therapeutic tunnel manipulation. This study investigated the angular rotations of the distal carpal joints as the CAW was adjusted. The CAW was narrowed and widened by 2 and 4 mm in seven cadaveric specimens while the bone positions were tracked by a marker-based motion capture system. The joints mainly pronated during CAW narrowing and supinated during widening. Ranges of motion about the pronation axis for the hamate-capitate (H-C), capitate-trapezoid (C-Td), and trapezoid-trapezium (Td-Tm) joints were 8.1 ± 2.3 deg, 5.3 ± 1.3 deg, and 5.5 ± 3.5 deg, respectively. Differences between the angular rotations of the joints were found at ΔCAW = −4 mm about the pronation and ulnar-deviation axes. For the pronation axis, angular rotations of the H-C joint were larger than that of the C-Td and Td-Tm joints. Statistical interactions among the factors of joint, rotation axis, and ΔCAW indicated complex joint motion patterns. The complex three-dimensional motion of the bones can be attributed to several anatomical constraints such as bone arrangement, ligament attachments, and articular congruence. The results of this study provide insight into the mechanisms of carpal tunnel adaptations in response to biomechanical alterations of the structural components.

scholarly journals 2-Amino-5-chloropyridinium cis-diaquadioxalatochromate(III) sesquihydrate

2012 ◽  
Vol 68 (6) ◽  
pp. m824-m825 ◽  
Author(s):  
Ichraf Chérif ◽  
Jawher Abdelhak ◽  
Mohamed Faouzi Zid ◽  
Ahmed Driss
Keyword(s):  
Rotation Axis ◽  
Three Dimensional ◽  
Octahedral Geometry ◽  
Distorted Octahedral Geometry ◽  
Water Molecules ◽  
Lattice Water ◽  
Compound C ◽  
Hydrogen Bonding Interactions ◽  
Distorted Octahedral ◽  
Independent Lattice

In the crystal structure of the title compound, (C5H6ClN2)[Cr(C2O4)2(H2O)2]·1.5H2O, the CrIII atom adopts a distorted octahedral geometry being coordinated by two O atoms of two cis water molecules and four O atoms from two chelating oxalate dianions. The cis-diaquadioxalatochromate(III) anions, 2-amino-5-chloropyridinium cations and uncoordinated water molecules are linked into a three-dimensional supramolecular array by O—H...O and N—H...O hydrogen-bonding interactions. One of the two independent lattice water molecules is situated on a twofold rotation axis.

scholarly journals Feedback of patient survey on medication improves the management of polypharmacy: a pilot trial

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Yuta Hirose ◽  
Kiyoshi Shikino ◽  
Yoshiyuki Ohira ◽  
Sumihide Matsuoka ◽  
Chihiro Mikami ◽  
...  
Keyword(s):  
Health Professionals ◽  
Questionnaire Survey ◽  
Pilot Trial ◽  
Patient Survey ◽  
Contributing Factors ◽  
Chi Square ◽  
Oral Medications ◽  
Medical Institutions ◽  
Chi Square Test ◽  
Survey Results

Abstract Background Patient awareness surveys on polypharmacy have been reported previously, but no previous study has examined the effects of sending feedback to health professionals on reducing medication use. Our study aimed to conduct a patient survey to examine factors contributing to polypharmacy, feedback the results to health professionals, and analyze the resulting changes in the number of polypharmacy patients and prescribed medications. Methods After conducting a questionnaire survey of patients in Study 1, we provided its results to the healthcare professionals, and then surveyed the number of polypharmacy patients and oral medications using a before-after comparative study design in Study 2. In Study 1, we examined polypharmacy and its contributing factors by performing logistic regression analysis. In Study 2, we performed a t-test and a chi-square test. Results In the questionnaire survey, significant differences were found in the following 3 items: age (odds ratio (OR) = 3.14; 95% confidence interval (CI) = 2.01–4.91), number of medical institutions (OR = 2.34; 95%CI = 1.50–3.64), and patients’ difficulty with asking their doctors to deprescribe their medications (OR = 2.21; 95%CI = 1.25–3.90). After the feedback, the number of polypharmacy patients decreased from 175 to 159 individuals and the mean number of prescribed medications per patient decreased from 8.2 to 7.7 (p < 0.001, respectively). Conclusions Providing feedback to health professionals on polypharmacy survey results may lead to a decrease in the number of polypharmacy patients. Factors contributing to polypharmacy included age (75 years or older), the number of medical institutions (2 or more institutions), and patients’ difficulty with asking their physicians to deprescribe their medications. Feedback to health professionals reduced the percentage of polypharmacy patients and the number of prescribed medications. Trial registration UMIN. Registered 21 June 2020 - Retrospectively registered, https://www.umin.ac.jp/ctr/index-j.htm

Parameterization of Three-Dimensional Rigid Body Guidance Incorporating Planar Gear Connections in a Spatial Closed-Loop Mechanism With Parallel Consecutive Axes

2008 ◽  
Author(s):  
Javier Rolda´n Mckinley ◽  
Carl Crane ◽  
David B. Dooner
Keyword(s):  
Computer Animation ◽  
Closed Loop ◽  
Three Dimensional ◽  
Motion Generation ◽  
Repetitive Motion ◽  
End Effector ◽  
Spatial Mechanism ◽  
Joint Axis ◽  
Position And Orientation ◽  
Six Degree Of Freedom

This paper introduces a reconfigurable closed-loop spatial mechanism that can be applied to repetitive motion tasks. The concept is to incorporate five pairs of non-circular gears into a six degree-of–freedom closed-loop spatial chain. The gear pairs are designed based on given mechanism parameters and a user defined motion specification of a coupler link of the mechanism. It is shown in the paper that planar gear pairs can be used if the spatial closed-loop chain is comprised of six pairs of parallel joint axes, i.e. the first joint axis is parallel to the second, the third is parallel to the fourth, ..., and the eleventh is parallel to the twelfth. This paper presents the synthesis of the gear pairs that satisfy a specified three-dimensional position and orientation need. Numerical approximations were used in the synthesis the non-circular gear pairs by introducing an auxiliary monotonic parameter associated to each end-effector position to parameterize the motion needs. The findings are supported by a computer animation. No previous known literature incorporates planar non-circular gears to fulfill spatial motion generation needs.

BIOMECHANICAL ANALYSIS OF THE STANDING LONG JUMP

2003 ◽  
Vol 15 (05) ◽  
pp. 186-192 ◽  
Author(s):  
WEN-LAN WU ◽  
JIA-HROUNG WU ◽  
HWAI-TING LIN ◽  
GWO-JAW WANG
Keyword(s):  
Knee Joint ◽  
Motion Analysis ◽  
Joint Angle ◽  
Three Dimensional ◽  
The Body ◽  
Initial Angle ◽  
Knee Joint Angle ◽  
Standing Long Jump ◽  
Long Jump ◽  
Arm Motion

The purposes of the present study were to (1) investigate the effects of the arm movement and initial knee joint angle employed in standing long jump by the ground reaction force analysis and three-dimensional motion analysis; and (2) investigate how the jump performance of the female gender related to the body configuration. Thirty-four healthy adult females performed standing long jump on a force platform with full effort. Body segment and joint angles were analyzed by three-dimensional motion analysis system. Using kinetic and kinematic data, the trajectories on mass center of body, knee joint angle, magnitude of peak takeoff force, and impulse generation in preparing phase were calculated. Average standing long jump performances with free arm motion were +1.5 times above performance with restricted arm motion in both knee initial angles. The performances with knee 90° initial flexion were +1.2 times above performance with knee 45° initial flexion in free and restricted arm motions. Judging by trajectories of the center mass of body (COM), free arm motion improves jump distance by anterior displacement of the COM in starting position. The takeoff velocity with 90° knee initial angle was as much as 11% higher than in with 45° knee initial angle. However, the takeoff angles on the COM trajectory showed no significant differences between each other. It was found that starting jump from 90° bend knee relatively extended the time that the force is applied by the leg muscles. To compare the body configurations and the jumping scores, there were no significant correlations between jump scores and anthropometry data. The greater muscle mass or longer leg did not correlated well with the superior jumping performance.

In Vivo Tracking of the Human Patella Using Cine Phase Contrast Magnetic Resonance Imaging

1999 ◽  
Vol 121 (6) ◽  
pp. 650-656 ◽  
Author(s):  
F. T. Sheehan ◽  
F. E. Zajac ◽  
J. E. Drace
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Knee Joint ◽  
Phase Contrast ◽  
Three Dimensional ◽  
Resonance Imaging ◽  
Contrast Magnetic Resonance ◽  
Knee Joint Kinematics ◽  
Cine Phase Contrast

Improper patellar tracking is often considered to be the cause of patellar-femoral pain. Unfortunately, our knowledge of patellar-femoral-tibial (knee) joint kinematics is severely limited due to a lack of three-dimensional, noninvasive, in vivo measurement techniques. This study presents the first large-scale, dynamic, three-dimensional, noninvasive, in vivo study of nonimpaired knee joint kinematics during volitional leg extensions. Cine-phase contrast magnetic resonance imaging was used to measure the velocity profiles of the patella, femur, and tibia in 18 unimpaired knees during leg extensions, resisted by a 34 N weight. Bone displacements were calculated through integration and then converted into three-dimensional orientation angles. We found that the patella displaced laterally, superiorly, and anteriorly as the knee extended. Further, patellar flexion lagged knee flexion, patellar tilt was variable, and patellar rotation was fairly constant throughout extension.

The Subtalar Joint Axis Locator

2006 ◽  
Vol 96 (3) ◽  
pp. 212-219 ◽  
Author(s):  
Simon K. Spooner ◽  
Kevin A. Kirby
Keyword(s):  
Subtalar Joint ◽  
Dynamic Capabilities ◽  
Three Dimensional ◽  
Spatial Location ◽  
Exit Point ◽  
Neck Position ◽  
Dorsal Aspect ◽  
Joint Axis ◽  
Preliminary Study ◽  
Rotational Motions

A new clinical device, the subtalar joint axis locator, was created to track the three-dimensional location of the subtalar joint axis during weightbearing movements of the foot. The assumption was that if the anterior exit point of the subtalar joint axis is stationary relative to the dorsal aspect of the talar neck, then, by performing radiographs of the feet with the subtalar joint axis locator in place on the foot, the ability of the locator to track rotations and translations of the talar neck and thus the subtalar joint axis in space could be approximated. In this preliminary study of two adults, the subtalar joint axis locator accurately tracked the talar neck position during weightbearing rotational motions of the subtalar joint. The device was also used in a series of subjects to determine its dynamic capabilities. It is possible, then, that the subtalar joint axis locator can reliably track the spatial location of the subtalar joint axis during weightbearing movements of the foot. (J Am Podiatr Med Assoc 96(3): 212–219, 2006)

scholarly journals Crystal structure ofcatena-poly[[diaquabis(4-formylbenzoato-κO1)cobalt(II)]-μ-pyrazine-κ2N:N′]

2015 ◽  
Vol 71 (4) ◽  
pp. 339-341 ◽  
Author(s):  
Gülçin Şefiye Aşkın ◽  
Fatih Çelik ◽  
Nefise Dilek ◽  
Hacali Necefoğlu ◽  
Tuncer Hökelek
Keyword(s):  
Hydrogen Bonds ◽  
Rotation Axis ◽  
Three Dimensional ◽  
Water Molecules ◽  
Carboxylate Group ◽  
Polymeric Compound ◽  
Distorted Octahedral Coordination ◽  
Linear Chains ◽  
Dimensional Network ◽  
Distorted Octahedral

In the title polymeric compound, [Co(C8H5O3)2(C4H4N2)(H2O)2]n, the CoIIatom is located on a twofold rotation axis and has a slightly distorted octahedral coordination sphere. In the equatorial plane, it is coordinated by two carboxylate O atoms of two symmetry-related monodentate formylbenzoate anions and by two N atoms of two bridging pyrazine ligands. The latter are bisected by the twofold rotation axis. The axial positions are occupied by two O atoms of the coordinating water molecules. In the formylbenzoate anion, the carboxylate group is twisted away from the attached benzene ring by 7.50 (8)°, while the benzene and pyrazine rings are oriented at a dihedral angle of 64.90 (4)°. The pyrazine ligands bridge the CoIIcations, forming linear chains running along theb-axis direction. Strong intramolecular O—H...O hydrogen bonds link the water molecules to the carboxylate O atoms. In the crystal, weak O—Hwater...Owaterhydrogen bonds link adjacent chains into layers parallel to thebcplane. The layers are linkedviaC—Hpyrazine...Oformylhydrogen bonds, forming a three-dimensional network. There are also weak C—H...π interactions present.

Coaches attitudes about returning to play in youth and varsity sports post- COVID-19

2021 ◽  
Vol 18 (2) ◽  
pp. 292-330
Author(s):  
Joe Deutsch ◽  
Roman Waldera
Keyword(s):  
High School ◽  
Statistical Significance ◽  
Research Result ◽  
Return To Play ◽  
Chi Square ◽  
School Sport ◽  
High School Sport ◽  
Face To Face Instruction ◽  
Athletic Leaders ◽  
Sport Coaches

BACKGROUND: One industry affected by the COVID-19 mandated social distancing policies is sport. In the wake of pressures to return to some normalcy, sport leagues have begun a return to play, many of which include regulations additional to the typical athlete and fan experience. Youth, Middle School, and High School sport leagues are of specific interest in America given the currently inconclusive national plan for returning to face-to-face instruction of students at schools. PURPOSE: The current goal is to identify the perceptions and experiences of current sport professionals throughout the country regarding a return to play. METHODS: The participants of this study were 181 Youth and High School Sport Coaches of various sports. The sample contained males (n = 123) and females (n = 58). The age of respondents ranged from 20 or more years of age. A return to play questionnaire was created and used to collect data for this study. The survey consisted of 12 yes or no questions regarding a return to play during the pandemic, with an opportunity for an open-ended explanation for each. Statistical methods employed to conduct data analysis included frequencies to determine percentages. A crosstabs analysis and Pearson Chi-Square tests of association were utilized to identify statistical significance within the variables. FINDING: No statistically significant association was found at the p ≤ .05 level between age or years of coaching experience and any response to a yes/no question. Percentages for high school coaches who responded "Yes" to each question are presented. Due to the wide variety of responses in these open-ended explanations, statistical expressions were not conducted, and an inclusive list of explanations for each question is provided. CONCLUSION: While the research result is unclear, the information obtained from coaches in the current study presents a small illustration of the current perceptions of athletic leaders in this region regarding the return to play of youth sport coaches and their respective schools' policies.

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