scholarly journals Comparison of the kinematics, repeatability, and reproducibility of five different multi-segment foot models

2022 ◽  
Vol 15 (1) ◽  
Author(s):  
Hyo Jeong Yoo ◽  
Hye Sun Park ◽  
Dong-Oh Lee ◽  
Seong Hyun Kim ◽  
Gil Young Park ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Statistical Parametric Mapping ◽  
Standard Errors ◽  
Foot And Ankle ◽  
Multiple Correlation ◽  
Experimental Conditions ◽  
Repeatability And Reproducibility ◽  
Goniometric Measurements ◽  
Frame Construction ◽  
Acceptable Reliability

Abstract Background Multi-segment foot models (MFMs) for assessing three-dimensional segmental foot motions are calculated via various analytical methods. Although validation studies have already been conducted, we cannot compare their results because the experimental environments in previous studies were different from each other. This study aims to compare the kinematics, repeatability, and reproducibility of five MFMs in the same experimental conditions. Methods Eleven healthy males with a mean age of 26.5 years participated in this study. We created a merged 29-marker set including five MFMs: Oxford (OFM), modified Rizzoli (mRFM), DuPont (DFM), Milwaukee (MiFM), and modified Shriners Hospital for Children Greenville (mSHCG). Two operators applied the merged model to participants twice, and then we analysed two relative angles of three segments: shank-hindfoot (HF) and hindfoot-forefoot (FF). Coefficients of multiple correlation (CMC) and mean standard errors were used to assess repeatability and reproducibility, and statistical parametric mapping (SPM) of the t-value was employed to compare kinematics. Results HF varus/valgus of the MiFM and mSHCG models, which rotated the segment according to radiographic or goniometric measurements during the reference frame construction, were significantly more repeatable and reproducible, compared to other models. They showed significantly more dorsiflexed HF and plantarflexed FF due to their static offset angles. DFM and mSHCG showed a greater range of motion (ROM), and some models had significantly different FF points of peak angle. Conclusions Under the same conditions, rotating the segment according to the appropriate offset angle obtained from radiographic or goniometric measurement increased reliability, but all MFMs had clinically acceptable reliability compared to previous studies. Moreover, in some models, especially HF varus/valgus, there were differences in ROM and points of peak angle even with no statistical difference in SPM curves. Therefore, based on the results of this study, clinicians and researchers involved in the evaluation of foot and ankle dysfunction need an understanding of the specific features of each MFM to make accurate decisions.

Design and Marker-Based Validation of a Biplane Fluoroscopy System for Studying the Foot and Ankle

2012 ◽  
Author(s):  
Joseph M. Iaquinto ◽  
Richard Tsai ◽  
Michael J. Fassbind ◽  
David R. Haynor ◽  
Bruce J. Sangeorzan ◽  
...  
Keyword(s):  
Precise Measurement ◽  
Three Dimensional ◽  
The Body ◽  
Initial Evaluation ◽  
Foot And Ankle ◽  
Research Groups ◽  
The Past ◽  
Model Based ◽  
Biplane Fluoroscopy ◽  
Model Based Analysis

The ability to accurately measure three dimensional (3D) bone kinematics is key to understanding the motion of the joints of the body, and how such motion is altered by injury, disease, and treatment. Precise measurement of such kinematics is technically challenging. Biplane fluoroscopy is ideally suited to measure bone motion. Such systems have been developed in the past for both radiographic stereo-photogrammetric analysis (RSA) [1] and the more challenging model-based analysis [2]. Research groups have studied the knee [3,4], shoulder [5] and ankle [6] motion with similar techniques. The work presented here is an initial evaluation of the performance of our system, i.e., a validation that this in-house system can detect magnitudes of motion on-par with other existing systems.

scholarly journals Repeatability and reproducibility of landmarks--a three-dimensional computed tomography study

2011 ◽  
Vol 34 (3) ◽  
pp. 276-286 ◽  
Author(s):  
I. Titiz ◽  
M. Laubinger ◽  
T. Keller ◽  
K. Hertrich ◽  
U. Hirschfelder
Keyword(s):  
Computed Tomography ◽  
Three Dimensional ◽  
Repeatability And Reproducibility

scholarly journals Numerical and experimental study on turbulence statistics in a large fan-stirred combustion vessel

2021 ◽  
Vol 62 (5) ◽  
Author(s):  
M. E. Morsy ◽  
J. Yang
Keyword(s):  
Isotropic Turbulence ◽  
Burning Velocity ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Turbulence Models ◽  
Initial Pressure ◽  
Dynamics Modeling ◽  
Turbulence Statistics ◽  
Experimental Conditions ◽  
Measured Velocity

Abstract Particle image velocimetry (PIV) has become a popular non-intrusive tool for measuring various types of flows. However, when measuring three-dimensional flows with two-dimensional (2D) PIV, there are some uncertainties in the measured velocity field due to out-of-plane motion, which might alter turbulence statistics and distort the overall flow characteristics. In the present study, three different turbulence models are employed and compared. Mean and fluctuating fields obtained by three-dimensional computational fluid dynamics modeling are compared to experimental data. Turbulence statistics such as integral length scale, Taylor microscale, Kolmogorov scale, turbulence kinetic energy, dissipation rate, and velocity correlations are calculated at different experimental conditions (i.e., pressure, temperature, fan speed, etc.). A reasonably isotropic and homogeneous turbulence with large turbulence intensities is achieved in the central region extending to almost 45 mm radius. This radius decreases with increasing the initial pressure. The influence of the third dimension velocity component on the measured characteristics is negligible. This is a result of the axisymmetric features of the flow pattern in the current vessel. The results prove that the present vessel can be conveniently adopted for several turbulent combustion studies including mainly the determination of turbulent burning velocity for gaseous premixed flames in nearly homogeneous isotropic turbulence. Graphic abstract

Secondary motion in convection layers generated by lateral heating of a solute gradient

2002 ◽  
Vol 455 ◽  
pp. 1-19 ◽  
Author(s):  
CHO LIK CHAN ◽  
WEN-YAU CHEN ◽  
C. F. CHEN
Keyword(s):  
Stability Analysis ◽  
Linear Stability ◽  
Linear Stability Analysis ◽  
Fluid Motion ◽  
Three Dimensional ◽  
Convection Cell ◽  
Experimental Conditions ◽  
Longitudinal Plane ◽  
Secondary Motion ◽  
Solute Gradient

The three-dimensional motion observed by Chen & Chen (1997) in the convection cells generated by sideways heating of a solute gradient is further examined by experiments and linear stability analysis. In the experiments, we obtained visualizations and PIV measurements of the velocity of the fluid motion in the longitudinal plane perpendicular to the imposed temperature gradient. The flow consists of a horizontal row of counter-rotating vortices within each convection cell. The magnitude of this secondary motion is approximately one-half that of the primary convection cell. Results of a linear stability analysis of a parallel double-diffusive flow model of the actual ow show that the instability is in the salt-finger mode under the experimental conditions. The perturbation streamlines in the longitudinal plane at onset consist of a horizontal row of counter-rotating vortices similar to those observed in the experiments.

scholarly journals Effects of additional load at different heights on gait initiation: A statistical parametric mapping of center of pressure and center of mass behavior

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0242892
Author(s):  
Marcus Fraga Vieira ◽  
Fábio Barbosa Rodrigues ◽  
Alfredo de Oliveira Assis ◽  
Eduardo de Mendonça Mesquita ◽  
Thiago Santana Lemes ◽  
...  
Keyword(s):  
Time Series ◽  
Center Of Pressure ◽  
Center Of Mass ◽  
Statistical Parametric Mapping ◽  
Gait Initiation ◽  
Experimental Conditions ◽  
Distributed Load ◽  
Uniformly Distributed Load ◽  
Reaction Forces ◽  
Controlled Object

The purpose of this study was to investigate the effects of different vertical positions of an asymmetrical load on the anticipatory postural adjustments phase of gait initiation. Sixty-eight college students (32 males, 36 females; age: 23.65 ± 3.21 years old; weight: 69.98 ± 8.15 kg; height: 1.74 ± 0.08 m) were enrolled in the study. Ground reaction forces and moments were collected using two force platforms. The participants completed three trials under each of the following random conditions: no-load (NL), waist uniformly distributed load (WUD), shoulder uniformly distributed load (SUD), waist stance foot load (WST), shoulder stance foot load (SST), waist swing foot load (WSW), and shoulder swing foot load (SSW). The paired Hotelling’s T-square test was used to compare the experimental conditions. The center of pressure (COP) time series were significantly different for the SUD vs. NL, SST vs. NL, WST vs. NL, and WSW vs. NL comparisons. Significant differences in COP time series were observed for all comparisons between waist vs. shoulder conditions. Overall, these differences were greater when the load was positioned at the shoulders. For the center of mass (COM) time series, significant differences were found for the WUD vs. NL and WSW vs. NL conditions. However, no differences were observed with the load positioned at the shoulders. In conclusion, only asymmetrical loading at the waist produced significant differences, and the higher the extra load, the greater the effects on COP behavior. By contrast, only minor changes were observed in COM behavior, suggesting that the changes in COP (the controller) behavior are adjustments to maintain the COM (controlled object) unaltered.

scholarly journals Outcomes of Tibiotalocalcaneal Arthrodesis using a Custom Three-Dimensional Printed Titanium Truss Implant

2020 ◽  
Vol 5 (4) ◽  
pp. 2473011420S0017
Author(s):  
Daniel Corr ◽  
Jared Raikin ◽  
Joseph T. O’Neil ◽  
Steven M. Raikin
Keyword(s):  
Postoperative Complications ◽  
Short Form ◽  
Three Dimensional ◽  
Functional Improvement ◽  
Salvage Procedure ◽  
Foot And Ankle ◽  
Hindfoot Alignment ◽  
Average Patient ◽  
Osseous Defects

Category: Ankle; Hindfoot Introduction/Purpose: Tibiotalocalcaneal (TTC) arthrodesis (fusion) is considered a salvage procedure for patients with severe hindfoot and ankle pathology. Several techniques have been described for TTC fusion, including the use of an intramedullary rod, plate and screw constructs, screws only, and external fixation/frames. Recently, 3D printing technology has allowed for a new technique to treat large hindfoot and ankle osseous defects with a custom three-dimensional (3D) titanium truss implant. These implants are specifically designed based on preoperative patient computed tomography (CT) scans. Early studies have shown promising radiographic and functional results, though these have been limited largely to expert opinions and case reports. The purpose of this study is to evaluate the clinical, radiographic, and functional outcomes of TTC arthrodesis using a custom 3D titanium truss implant. Methods: A retrospective review of patients who have undergone TTC arthrodesis utilizing a custom 3D-printed titanium truss implant (4WEB Medical, Inc., Frisco, TX) with a fellowship-trained orthopaedic foot and ankle surgeon at a single institution was performed. Patients <18 years old, and those undergoing TTC arthrodesis using any other primary method of filling osseous defects (i.e. femoral head allografts, autografts) were excluded. Patient demographics including age, sex, body mass index (BMI), smoking status, laterality of surgery, co-morbidities (diabetes mellitus, rheumatoid arthritis), preoperative diagnosis, previous hindfoot or ankle surgeries, and any postoperative complications were collected. Patients at least one year removed from the procedure were contacted to complete the Foot and Ankle Ability Measure (FAAM) Activities of Daily Living (ADL) subscale, along with the Visual Analog Scale for pain (VAS) and the Short Form-12 questionnaire (SF-12). Postoperative radiographs were reviewed to assess ankle and hindfoot alignment, implant integrity and any osseous abnormalities. Results: Eighteen patients underwent TTC fusion using custom titanium truss implants and were eligible for follow-up and analysis. Average patient age at the time of surgery was 58.7 years, and average BMI was 30.25 kg/m2. Seven patients (38.9%) were either current or former smokers, and 3 patients (16.7%) were diabetic. On average, patient FAAM ADL scores improved from 33.23 preoperatively to 59.56 (p=0.023), while VAS pain scores decreased from 59.07 to 34.22 (p<0.001). SF-12 Mental Health scores increased from 45.45 to 56.42 (p=0.031), while Physical Health scores improved mildly from 28.78 to 31.75 (p=0.110). Two patients (11.1%) had significant postoperative complications; one patient went on to require below knee amputation, and one patient demonstrated incomplete healing with implant loosening at their most recent follow-up. Conclusion: We have shown that custom titanium truss implants are viable and effective for use in TTC fusion. Use of such implants resulted in significant functional improvement among the cohort with low rates of complications and subsequent surgical interventions.

scholarly journals Three-Dimensional Flow Characteristics in Slit-Type Permeable Spur Dike Fields: Efficacy in Riverbank Protection

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 964 ◽  
Author(s):  
Shampa ◽  
Yuji Hasegawa ◽  
Hajime Nakagawa ◽  
Hiroshi Takebayashi ◽  
Kenji Kawaike
Keyword(s):  
Shear Stress ◽  
Longitudinal Velocity ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Efficient Solutions ◽  
Staggered Grid ◽  
Bed Shear Stress ◽  
Experimental Conditions ◽  
Alluvial Rivers ◽  
Spur Dike

This paper focuses on finding efficient solutions for the design of a highly permeable pile spur (or slit type) dike field used in morphologically dynamic alluvial rivers. To test the suitability of different arrangements of this type of permeable pile spur dike field, laboratory experiments were conducted, and a three-dimensional multiphase numerical model was developed and applied, based on the experimental conditions. Three different angles to the approach flow and two types of individual pile position arrangements were tested. The results show that by using a series of slit-type spurs, the approach velocity of the flow can be considerably reduced within the spur dike zone. Using different sets of angles and installation positions, this type of permeable spur dike can be used more efficiently than traditional dikes. Notably, this type of spur dike can reduce the longitudinal velocity, turbulence intensity, and bed shear stress in the near-bank area. Additionally, the deflection of the permeable spur produces more transverse flow to the opposite bank. Arranging the piles in staggered grid positions among different spurs in a spur dike field improves functionality in terms of creating a quasi-uniform turbulence zone while simultaneously reducing the bed shear stress. Finally, the efficacy of the slit-type permeable spur dike field as a solution to the riverbank erosion problem is numerically tested in a reach of a braided river, the Brahmaputra–Jamuna River, and a comparison is made with a conventional spur dike field. The results indicate that the proposed structure ensures the smooth passing of flow compared with that for the conventional impermeable spur structure by producing a lower level of scouring (low bed shear stress) and flow intensification.

Intraluminal three-dimensional optical coherence tomography – a tool for imaging of the Eustachian tube?

2019 ◽  
Vol 133 (2) ◽  
pp. 87-94 ◽  
Author(s):  
R Schuon ◽  
B Mrevlje ◽  
B Vollmar ◽  
T Lenarz ◽  
G Paasche
Keyword(s):  
Optical Coherence Tomography ◽  
Eustachian Tube ◽  
Cross Sections ◽  
Ex Vivo ◽  
Three Dimensional ◽  
Diagnostic Value ◽  
Optical Coherence ◽  
Experimental Conditions ◽  
Non Invasive ◽  
Tube Dysfunction

AbstractObjectivesThe cause of Eustachian tube dysfunction often remains unclear. Therefore, this study aimed to examine the feasibility and possible diagnostic use of optical coherence tomography in the Eustachian tube ex vivo.MethodsTwo female blackface sheep cadaver heads were examined bilaterally. Three conditions of the Eustachian tube were investigated: closed (resting position), actively opened and stented. The findings were compared (and correlated) with segmented histological cross-sections.ResultsIntraluminal placement of the Eustachian tube with the optical coherence tomography catheter was performed without difficulty. Regarding the limited infiltration depth of optical coherence tomography, tissues can be differentiated. The localisation of the stent was accurate as was the lumen.ConclusionThe application of optical coherence tomography in the Eustachian tube under these experimental conditions is considered to be a feasible, rapid and non-invasive diagnostic method, with possible diagnostic value for determining the luminal shape and superficial lining tissue of the Eustachian tube.

scholarly journals Spastic diparetic does not directly affect the capacity to ascend and descend access ramps: three-dimensional analysis

2017 ◽  
Vol 30 (3) ◽  
pp. 537-547 ◽  
Author(s):  
Tainá Ribas Mélo ◽  
Ana Tereza Bittencourt Guimarães ◽  
Vera Lúcia Israel
Keyword(s):  
Imaging System ◽  
Three Dimensional ◽  
Control Group ◽  
Initial Contact ◽  
Experimental Conditions ◽  
3 Dimensional ◽  
Flexion Extension ◽  
Posterior Trunk ◽  
Hip Flexion ◽  
Study Participants

Abstract Introduction: Diplegic children have difficulties in gait and therefore ramps are used as strategies of accessibility. Objective: The present study investigated the influence of an inclined surface (ascending and descending) on the kinematic characteristics during gait of the diplegic group (DG) when compared to typically developing children of the control group (CG). Methods: Study participants included 20 children (10 with DG and 10 CG) matched by age, which were evaluated in three experimental conditions (horizontal and inclined ascending and inclined descending surfaces of 7º) through an optoelectronic imaging system. Results: Among the linear kinematic variables, only step width differed among groups, however, without influence of the surface. The foot height differed among the groups only in the descending phase, where DG had greater difficulty in raising the foot. The 3-dimensional gait analyses could not provide more evidences of differences in kinematics variables, especially in transverse plane, between DG and CG, but provide some evidence to support that hip range of motion (ROM) during the gait cycle, hip flexion-extension in initial contact, knee ROM and the 2nd anterior-posterior trunk peak amplitude of the DG were influenced on descent by their flexor pattern. Conclusion: The DG was most affected by the inclination plane than CG especially on descent. Although a hip and knee flexor pattern is evident for DG on inclination of 7º, this angle is accessible since it allows independent gait functional activity.

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