arch height
Recently Published Documents


TOTAL DOCUMENTS

184
(FIVE YEARS 51)

H-INDEX

27
(FIVE YEARS 2)

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 192
Author(s):  
Tao Peng ◽  
Qiuhong Lin ◽  
Bingyan Li ◽  
Ani Luo ◽  
Qiang Cong ◽  
...  

In this paper, the stress superposition method (SSM) is proposed to solve the stress distribution of regular polygon membranes. The stress-solving coefficient and the calculation formula of arbitrary point stress of regular polygon membrane are derived. The accuracy of the SSM for calculating stresses in regular polygonal membranes is verified by comparing the calculation results of the SSM with the finite element simulation results. This article is the first to propose a method to investigate the response of the arch height of the membrane curved edge to the membrane’s mechanical properties while keeping the effective area constant. It is found that the equivalent stress and the second principal stress at the midpoint of the membrane curved edge are effectively increased with the increase of the arch height of the curved edge. The second principal stress at the edge region of the membrane is relatively small, leading to the occurrence of wrinkles. When the stress at the midpoint of the curved edge is equal to that at the center of the membrane, the membrane plane attains the maximum stiffness and reduces the possibility of wrinkling at the edge.


2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Guoyu Yang ◽  
Tao Shang ◽  
Liu Han ◽  
Tao Chen

To study the influence of profile shape on the stability of nonhomogeneous slopes, strip mechanical models of slopes with different profile shapes were established following the simplified Bishop method. Three hundred and seventy slope models with different profile shapes and strata sequences were simulated and analyzed with FLAC3D. The results show that slopes with weaker-to-stronger (WtS) strata sequences are, in most cases, more stable than slopes with stronger-to-weaker (StW) strata sequences when all other conditions are the same. Slopes with linear shapes are the most stable. With increasing arch height, the stability of convex slopes decreases, and the stability of concave slopes first increases slightly and then decreases. When the strata sequences are WtS, the factors of safety (FoSs) of slopes with convex and exterior polyline shapes decrease more slowly. However, when the strata sequences are StW, the FoSs of slopes with concave and interior polyline shapes decrease more slowly. The greatest X-displacements are concentrated in the steeper areas of the slopes. For different strata sequences, the higher the rock strength at the steeper position is, the more stable the slope is, and the opposite trend is also observed. For the same strata sequence, the stability of a polyline-shaped slope is always better than that of a curved slope with the same inflection point.


PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0260398
Author(s):  
Daekyoo Kim ◽  
Cara L. Lewis ◽  
Simone V. Gill

Foot arch structure contributes to lower-limb joint mechanics and gait in adults with obesity. However, it is not well-known if excessive weight and arch height together affect gait mechanics compared to the effects of excessive weight and arch height alone. The purpose of this study was to determine the influences of arch height and obesity on gait mechanics in adults. In this study, 1) dynamic plantar pressure, 2) spatiotemporal gait parameters, 3) foot progression angle, and 4) ankle and knee joint angles and moments were collected in adults with normal weight with normal arch heights (n = 11), normal weight with lower arch heights (n = 10), obesity with normal arch heights (n = 8), and obesity with lower arch heights (n = 18) as they walked at their preferred speed and at a pedestrian standard walking speed, 1.25 m/s. Digital foot pressure data were used to compute a measure of arch height, the Chippaux-Smirak Index (CSI). Our results revealed that BMI and arch height were each associated with particular measures of ankle and knee joint mechanics during walking in healthy young adults: (i) a higher BMI with greater peak internal ankle plantar-flexion moment and (ii) a lower arch height with greater peak internal ankle eversion and abduction moments and peak internal knee abduction moment (i.e., external knee adduction moment). Our results have implications for understanding the role of arch height in reducing musculoskeletal injury risks, improving gait, and increasing physical activity for people living with obesity.


Author(s):  
Megan Balsdon ◽  
Michaela E Khan ◽  
Dillon Richards ◽  
Colin E Dombroski

BACKGROUND: Normative studies on the Arch Height Index (AHI), Arch Rigidity Index (ARI), and arch stiffness have primarily focused on healthy populations, with little consideration of pathology. The purpose of this study was to create a normative sample of the aforementioned measurements in a pathological sample and to identify relationships between arch structure measurements and pathology. METHODS: AHI was obtained bilaterally at 10% and 90% weightbearing conditions using the Arch Height Index Measurement System (AHIMS). ARI and arch stiffness were calculated using AHI measurements. Dependent t-tests compared right and left, dominant and non-dominant, and injured and non-injured limbs. Measurements of the dominant foot were compared between sexes using independent t-tests. Relationships between arch stiffness and age, sex, and AHI were examined using the coefficient of determination (R2). One-way ANOVAs were used to determine differences between arch structure measurements and number of pathologies or BMI. RESULTS: A total of 110 participants reported either one (n=55), two (n=38), or three or more (n=17) pathologies. Plantar fasciitis (n=31) and hallux valgus (n=28) were the most commonly reported primary concerns. AHI, ARI, and arch stiffness did not differ between limbs for any comparisons, nor between sexes. Between subgroups of BMI and number of pathologies, no differences exist in AHI or ARI; however, BMI was found to have an impact on AHI (10%WB) and arch stiffness (p<.05). Arch stiffness showed a weak relationship to AHI, where a higher AHI was associated with a stiffer arch (R2=0.06). CONCLUSIONS: Normative AHI, ARI and arch stiffness values were established in a pathological sample with a large incidence of plantar fasciitis and hallux valgus. Findings suggest relationships between arch stiffness and both BMI and arch height; however, few trends were noted in AHI and ARI. Determining relationships between arch structure and pathology is helpful for both clinicians and researchers.


Author(s):  
Ondřej Laštovička ◽  
Roman Cuberek ◽  
Miroslav Janura ◽  
Tomáš Klein

Background: Foot dimension information is important both for footwear design and clinical applications. In recent years, non-contact three-dimensional foot digitizers/scanners became popular as they are non-invasive and are both valid and reliable for the most of measures. Some of them also offer automated calculations of basic foot dimensions. The study aimed to determine test-retest reliability, objectivity, and concurrent validity of the Tiger full foot 3D scanner as well as the relationship between the manual measures of the medial longitudinal arch of the foot and its alternative parameters obtained automatically by the scanner. Methods: Intraclass correlation coefficients and the values of minimal detectable change were used to assess the reliability and objectivity of the scanner. Concurrent validity and the relationship between the arch height measures were determined by the Pearson's correlation coefficient and the limits of agreement between the scanner and the calliper method. Results: Both the relative and absolute agreement between the repeated measurements obtained by the scanner show excellent reliability and objectivity of linear measures and only good to nearly good test-retest reliability and objectivity of the arch height. Correlations between the values obtained by the scanner and the calliper were generally higher in linear measures (rp{greater than or equal to}0.929). The representativeness of state of bony architecture by the soft tissue margin of the medial foot arch demonstrate the lowest correlations among the all measurements (rp{less than or equal to}0.526). Conclusions: The Tiger full foot 3D scanner offers both excellent reliability and objectivity in linear measures, which correspond to those obtained by the calliper method. However, values obtained by the both methods shouldn't be used interchangeably. The arch height measure is less accurate, which could limit its use in some clinical applications. Orthotists and related professions probably appreciate scanner more than other specialists.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12385
Author(s):  
Ewa Puszczalowska-Lizis ◽  
Karolina Koziol ◽  
Jaroslaw Omorczyk

Background Adequate footwear comfort and functionality are important regardless of age, but they become particularly important in the youngest-old women and men, mainly due to the fact that this age range is the initial period of old age with changes in shoe preferences. The aim of this study was to assess the perception of footwear comfort and its relationship with the feet structure in youngest-old women and men. Methods The cross-sectional study covered community dwellers living on their own aged 65–74 years (50 women; 50 men). The feet characteristics were measured using the CQ-ST podoscope (Electronic System, Ltd, EU), and the perception of footwear comfort was assessed with a visual analogue scale. The assessment took into account gender-specific footwear of a certain brand (Befado Dr orto). Results Statistically significant intergender differences were observed in the perception of footwear comfort with respect to the shoe heel width (p = 0.022), the arch height (p = 0.013), the overall comfort (p = 0.049) and the material properties of the footwear (p = 0.017). In women, there were statistically significant positive relationships among the heel angle (γ) and the perception of footwear comfort in terms of heel cushioning (p = 0.021), forefoot cushioning (p = 0.015), arch height (p = 0.029). In men, there was a statistically significant negative relationship of the left foot Clarke’s angle with the heel height (p = 0.043), and a positive relationship between the right foot width and the arch height (p = 0.044). Conclusions Youngest-old women, compared to men of the same age range, have a higher perception of shoe comfort in terms of the shoe heel width, the arch height, the overall comfort of the footwear and the material properties of the footwear. The appropriate profile and construction of the shoe allows for an increase in the contact surface of the foot with the shoe, hence the improvement in the perception of footwear comfort in people with lowered arch or widened forefoot.


2021 ◽  
Author(s):  
Seon Woong Choi ◽  
Hoon Kim ◽  
Seong Rim Kim ◽  
Ik Seong Park ◽  
Sunghan Kim

ABSTRACTIntroductionTransradial angiography (TRA) has received considerable attention in the field of neurointervention owing to its advantages over transfemoral approaches. However, the difficulty of left internal carotid artery (ICA) catheterization under certain anatomical conditions of the aortic arch and its branches is a limitation of TRA. This study aimed to investigate the anatomical predictors of successful catheterization of the left ICA in TRA.Materials and MethodsFrom January 2020 to October 2020, 640 patients underwent TRA at a single institute. Among them, 263 consecutive patients who were evaluated by contrast-enhanced MRI before TRA were included in our study and assigned to success and failure groups, according to whether left ICA catheterization was possible or not. Anatomical predictors that may affect the success of left ICA catheterization in TRA were investigated for the purposes of our study.ResultsThe multivariable analysis included variables that demonstrated significant univariate associations with ICA catherization (P<0.0001). Variables included in the model were the type of aortic arch, height of right subclavian artery, turn-off angle of the left common carotid artery (CCA), distance between innominate artery to the left CCA, angulation of right subclavian artery, and angulation of the left CCA, which we identified as significant predictors of left ICA catheterization.ConclusionSuccess of left ICA catheterization in TRA was related to the vascular geometry of the aortic arch and its branches. Evaluating the anatomical predictors identified in this study using pre-procedure imaging may enhance the success rate of left ICA catheterization in TRA.


Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5297
Author(s):  
Ka-Wing Cheng ◽  
Yinghu Peng ◽  
Tony Lin-Wei Chen ◽  
Guoxin Zhang ◽  
James Chung-Wai Cheung ◽  
...  

The advancement of 3D printing and scanning technology enables the digitalization and customization of foot orthosis with better accuracy. However, customized insoles require rectification to direct control and/or correct foot deformity, particularly flatfoot. In this exploratory study, we aimed at two design rectification features (arch stiffness and arch height) using three sets of customized 3D-printed arch support insoles (R+U+, R+U−, and R−U+). The arch support stiffness could be with or without reinforcement (R+/−) and the arch height may or may not have an additional elevation, undercutting (U+/−), which were compared to the control (no insole). Ten collegiate participants (four males and six females) with flexible flatfoot were recruited for gait analysis on foot kinematics, vertical ground reaction force, and plantar pressure parameters. A randomized crossover trial was conducted on the four conditions and analyzed using the Friedman test with pairwise Wilcoxon signed-rank test. Compared to the control, there were significant increases in peak ankle dorsiflexion and peak pressure at the medial midfoot region, accompanied by a significant reduction in peak pressure at the hindfoot region for the insole conditions. In addition, the insoles tended to control hindfoot eversion and forefoot abduction though the effects were not significant. An insole with stronger support features (R+U+) did not necessarily produce more favorable outcomes, probably due to over-cutting or impingement. The outcome of this study provides additional data to assist the design rectification process. Future studies should consider a larger sample size with stratified flatfoot features and covariating ankle flexibility while incorporating more design features, particularly medial insole postings.


2021 ◽  
Author(s):  
Lauren Williams ◽  
Sarah Ridge ◽  
A. Wayne Johnson ◽  
Elisa S. Arch ◽  
Dustin A. Bruening

Abstract Background: Previous research shows kinematic and kinetic coupling between the metatarsophalangeal (MTP) and midtarsal joints during gait. Studying the effects of MTP position as well as foot structure on this coupling may help determine to what extent foot coupling during dynamic and active movement is due to the windlass mechanism. This study’s purpose was to investigate the kinematic and kinetic foot coupling during controlled passive, active, and dynamic movements. Methods: After arch height and flexibility were measured, participants performed four conditions: Seated Passive MTP Extension, Seated Active MTP Extension, Standing Passive MTP Extension, and Standing Active MTP Extension. Next, participants performed three heel raise conditions that manipulated the starting position of the MTP joint: Neutral, Toe Extension, and Toe Flexion. A multisegment foot model was created in Visual 3D and used to calculate ankle, midtarsal, and MTP joint kinematics and kinetics. Results: Kinematic coupling (ratio of midtarsal to MTP angular displacement) was approximately six times greater in Neutral heel raises compared to Seated Passive MTP Extension, suggesting that the windlass only plays a small kinematic role in dynamic tasks. As the starting position of the MTP joint became increasingly extended during heel raises, the amount of negative work at the MTP joint and positive work at the midtarsal joint increased proportionally, while distal-to-hindfoot work remained unchanged. Correlations suggest that there is not a strong relationship between static arch height/flexibility and kinematic foot coupling. Conclusions: Our results show that there is kinematic and kinetic coupling within the distal foot, but this coupling is attributed only in small measure to the windlass mechanism. Additional sources of coupling include foot muscles and elastic energy storage and return within ligaments and tendons. Furthermore, our results suggest that the plantar aponeurosis does not function as a rigid cable but likely has extensibility that affects the effectiveness of the windlass mechanism. Arch structure did not affect foot coupling, suggesting that static arch height or arch flexibility alone may not be adequate predictors of dynamic foot function.


2021 ◽  
Author(s):  
Jian-Hai Bai ◽  
Xiao-Xiao Ruan ◽  
Yu Zhang ◽  
Xiao-Min Ding ◽  
Xing-Zhi Yang ◽  
...  

Abstract Objective This study aims to analyze and compare the postoperative ocular parameters of two different types of implantable contact lenses (ICLs) (for retinal detachment) to provide a clinical reference for vitreoretinal surgery. Methods From March 2016 to March 2021, 24 patients (24 eyes) with rhegmatogenous retinal detachment following ICL implantation at the Eye Center of Taizhou Central Hospital were recruited. Based on the different types of ICL, they were divided into the V4 type ICL implantation group (V4 type group) and v4C type ICL implantation group (v4C type group), with 12 cases (12 eyes) in each group. Both groups were treated with pars plana vitrectomy; differences in postoperative ocular complications between the two groups were compared. Results The postoperative uncorrected and best corrected visual acuity for both groups were significantly higher than those preoperatively (P < 0.001); the same applied to the intraocular pressures (P < 0.05). Fluctuation in intraocular pressure was higher in the V4 group than in the v4C group (P < 0.05). The arch height, measured using anterior segment optical coherence tomography on the first day after operation, was lower in the V4 group than in the v4C group (P < 0.05). There was also no significant difference between the two groups before and after the operation (P > 0.05). Conclusion For patients with V4 type ICL implantation and mesh removal, stimulation of the ciliary body and the risk factors for pupil block caused by ciliary muscle spasm should be reduced as much as possible during pars plana vitrectomy. If postoperative complications such as decreased arch height and increased intraocular pressure occur, the application of compound tropicamide eye drops is an effective method to activate the pupil.


Sign in / Sign up

Export Citation Format

Share Document