Arch Height Research Articles

Efficacy of Tibialis Posterior Strengthening Exercise with Obesity Reduction Program in Flexible Flatfoot among Obese School Children

Background: Flat foot (Pes Planus), is characterized by a reduced or absent medial longitudinal arch.Flat foot can be caused by many factors, including obesity, wearing shoes, weakness of muscles. Flat foot in obese children is mainly caused by the presence of a plantar fatty pad under the medial longitudinal arch of the foot.Objective: To compare the Efficacy of Tibialis Posterior Strengthening Exercise with Obesity reduction program In Flexible Flatfoot among Obese School Children.Methodology: A Randomized control trial (RCT) was conducted on 50 obese subjects with flexible flat foot. Experimental group received both the intervention, and control group received only obesity reduction programme. The tibialis posterior strengthening exercise is performed for 30 minutes per day for 5 days a week for a period of 6 weeks. Obesity reduction programme performed for 30 minutes for 5 days a week for a period of 6 weeks. Result: There was a significant difference was noted within the Group- A and Group B. Hence, TPSE with ORP was found to be more effective compared to ORP to improve foot arch and physical activity level among obese school children with flexible flat foot.Conclusion: Tibialis posterior strengthening exercise with obesity reduction program was found superior to only obesity reduction program in improving foot arch height and physical activity level among obese school children with flexible flat foot

BIOMECHANICAL CHANGES IN THIRD TRIMESTER OF PREGNANT FEMALES IN COMPARISON WITH NON PREGNANT FEMALES OF SAME AGE GROUP


 Abstract 
 Background: During pregnancy, women experience several changes in the body’s physiology, morphology, and hormonal system which lead to biomechanical changes for example range of motion at cervical, lumbar, gait patterns and foot position, which is considered as a part of normal postural adaptations.
 Objective: To determine biomechanical variations between third trimester pregnant women and the non-pregnant women in terms of range of motion at the cervical and the lumbar spine, step length, stride length, speed and number of steps, arch height and anatomic position of foot.
 Methodology: It was a comparative cross sectional had a sample size 210 comprising of 69 pregnant females and 141 non pregnant females aging between 18 to 35 yrs. Assessment was done by using an iPhone®5S I handy level© app for measuring the range of motion at the cervical and lumbar spine. A 6” by 6” POP sheet for measuring step length, stride length, number of steps and speed and navicular drop test for arch height and anatomic position of foot respectively.
 Results: In the assessment of cervical and lumbar flexion and extension range of motion the non-pregnant females group had greater range in both flexion and extension than pregnant females with the P value <0.01. Pregnant females presented with the low arch height, pronated foot, decreased step length, stride length and speed than non-pregnant having P <0.001.
 Conclusion: Pregnant females had reduced range of motion at cervical and lumbar spine, a drop in arch height, pronated foot position, a decrease in speed, step and stride length was observed in comparison to the non-pregnant females of the same age group.

Increased toe flexor strength does not relate to altered postural sway during static upright standing after 12 weeks of multicomponent exercise training

ABSTRACT This study investigated whether an increase in toe flexor strength influenced postural control during static upright standing after 12 weeks of multicomponent exercise training in healthy young men. Twelve men (18–23 yrs) performed multicomponent exercise 3 days per week for 12 weeks. Twelve additional age-matched men were recruited for the untrained control group. The multicomponent exercise training consisted of strengthening and balance exercises for the foot and leg muscles. Toe flexor strength, foot arch height and postural control were assessed before, during, and after exercise training. Postural control was evaluated using the path of the centre of pressure, which was obtained with a force plate under three standing conditions: double-leg standing with eyes open, double-leg standing with eyes closed, and single-leg standing with eyes open. The dominant leg was used for single-leg standing. After exercise training, toe flexor strength increased by approximately 32% (p < 0.01), whereas the foot arch height did not change. The centre of pressure variables during double-leg standing did not change after exercise training; however, these variables decreased during single-leg standing. None of the variables in the control group changed after exercise training. The relative increase in toe flexor strength was not correlated with the relative improvement in the centre of pressure variables during single-leg standing after 12 weeks of exercise training (total length, r = 0.1734; mean velocity, r = 0.1734; sway area, r = −0.1372). These findings suggest that increased toe flexor strength has no significant effect on static postural control ability after exercise training in young men. Highlights Twelve weeks of multicomponent exercise training aimed at strengthening foot and leg muscles increased toe flexor strength. Multicomponent exercise training did not alter postural stability during double-leg standing, but improved postural stability during single-leg standing. Increased toe flexor strength did not relate to altered postural stability during static upright standings after 12 weeks of exercise training.

Ability of the Posterior Tibial Tendon to Restore Foot Alignment in Progressive Collapsing Foot Deformity: A Computational Study

Category:Ankle; Midfoot/Forefoot; OtherIntroduction/Purpose:Progressive collapsing foot deformity (PCFD) is a degenerative disorder of ligaments and tendons that encompasses a wide range of deformities, including arch height loss, hindfoot valgus, and forefoot abduction. The posterior tibial tendon (PTT) is the main active stabilizer of the arch. We hypothesize that it may become injured secondarily as it attempts to maintain foot stability when the ligaments, passive stabilizers, are attenuated. Several cadaveric studies have been conducted on the role of the PTT in PCFD, but the ability of the PTT to compensate for the loss of the ligamentous stabilizers has not been clearly characterized. We developed a high-fidelity finite element model of the foot to determine the PTT's ability to maintain foot stability when the principle ligamentous stabilizers are attenuated.Methods:The encapsulating soft tissue (EST), cartilage, and cortical and trabecular bones were reconstructed in Mimics from CT scan images of a female cadaveric foot weighing 60 kg. Tension-only spring elements were used to reflect all the ligaments in ANSYS. Bodyweight and tendon forces were applied using force vectors in the direction of their lines of action. The proximal tibia was fixed only in the vertical direction, allowing it to translate and rotate in all other degrees of freedom. Nonlinear frictional contacts were used between the EST and the ground, and between the cartilages. The flatfoot was simulated by removing all of the ligaments. We measured the foot alignment angles for the flatfoot and the foot with ruptured spring/deltoid ligament, while we gradually increased the force within the PTT. The measured angles were then compared to the intact foot to evaluate the ability of the PTT to restore foot alignment.Results:The models were validated by comparing the Meary's (MA), calcaneal pitch (CPA), hindfoot alignment (HAA), and talonavicular coverage angles (TCA) to clinically-derived values. In the flatfoot, an increase of the PTT force to approximately 700% of normal ('7 ×25.71 N=180 N') led to a nearly complete restoration of foot alignment (Fig. 1). The angles associated with arch height (MA/CPA) were restored to a lesser extent than those associated with hindfoot and forefoot alignment (HAA/TCA). For the foot with ruptured deltoid ligament, increasing force within the PTT by 500% led to a restoration of near normal hindfoot alignment (Fig. 1c). For the foot with ruptured spring ligament, the forefoot abduction was completely compensated only when the PTT force was increased to 1100% of normal (Fig. 1d).Conclusion:Almost seven times the normal PTT force is required to restore the foot to neutral alignment. Augmentation of PTT force to this extent is unrealistic. However, a lesser increase in PTT force provides partial alignment compensation.Furthermore, the restoration achieved by overloading the PTT primarily impacts the alignment of the hindfoot and forefoot rather than the arch. Because the PTT can partially restore foot alignment, it may become secondarily injured when the ligaments are torn. Strengthening of the PTT through therapeutic exercise can improve its ability to restore foot alignment and should be a cornerstone of non-operative treatment of PCFD.

Force-Chain-Based Analysis of Factors Influencing Pressure Arch Around Tunnel Under Earthquake

The force chain method is a powerful tool to analyze the pressure arch of a tunnel, which has important influence on the seismic stability of tunnel structures. The force distribution around the tunnel before and after an earthquake was observed with numerical simulation and shaking table test, and then some parameters related to the pressure arch around the tunnel were analyzed. The discrete element method software PFC was used to numerically simulate the variation of shape and height of pressure arch with tunnel depth before and after an earthquake. The effect of tunnel depth, span, section shape, lining stiffness, seismic spectrum, and seismic amplitude on the shape and height of pressure arch was numerically simulated. The numerical results show that the tunnel depth, span, section shape, and seismic amplitude have great effect on the pressure arch shape, while the lining stiffness and seismic spectrum has little effect on the pressure arch shape. In addition, the shaking table tests were conducted to observe the pressure arch shape before and after an earthquake, and the experimental results were applied to verify the numerical simulation results.

GENERAL CHARACTERISTICS OF RENAL CALICES OF A MATURE AND ELDERLY HUMAN

The use of non-invasive and minimally invasive diagnostic and treatment methods in modern urological practice dictates the need to study the location of the initial section of the extrarenal urinary tract. The aim of the study was to describe general characteristics of renal calices of a mature and elderly human. Material and methods. The study included 175 corrosive preparations of human pyelocalyceal complexes. Organometric study of number, shape of arches, linear parameters, volumes, ranking place in the ranking distribution of renal calyces volumes was performed. Results. The upper renal is characterized by a large height (14.8±9.2 mm) and a wide neck (7.2±2.3 mm) and the largest volume 1202-1246 mm3. The anterior superior renal calyx has round vault of medium diameter (6.7±2.3 mm) and medium height (7.2±3.1 mm), a narrow neck (5.0±1.6 mm) and a small stable volume (14.8 mm3). The anterior middle calyx has a round vault of medium diameter (7.4±2.2 mm) and height (10.7±5.1 mm) and a narrow neck (4.8±1.6 mm); its volume is 348.4 mm3. The anterior inferior renal calyx has medium diameter (7.2±2.3 mm) and height (8.9±4.6 mm) with a narrow neck (4.8±1.8 mm); its volume is 275.2-307.1 mm3. The posterior superior renal calyx has medium arch diameter (8.4±3.0 mm) and height (8.6±4.5 mm) with a narrow neck (5.7±2.1 mm) and a small stable volume (less than 500.0 mm3). The posterior middle renal calyx has medium diameter (7.2±2.3 mm) and height (10.7±5.1 mm) with a narrow neck (5.1±1.9 mm), medium volume (402.1 mm3). The posterior inferior renal calyx has medium diameter (7.2±2.2 mm) and height (7.0±3.6 mm) with a narrow neck (5.3±2.3 mm), small stable volume (402.1 mm3). The lower renal calyx has medium diameter (7.4±2.4 mm) and height (8.6±4.6 mm) with a narrow neck (5.7±2.2 mm) and medium volume (402.1 mm3). Conclusions. As a result of the study, we determined the general characteristics of the renal calyces of a person of mature and elderly ages. New morphological information about the structure of the pyelocalyceal complex can be used to improve the diagnosis and treatment of the kidneys extrarenal urinary tract.

Measuring the Degree of Feet Arches Curvature for Male and Female Physical Education Students as a Function of Sitting and Standing Positions

The study aimed to identify the degree of curvature of the feet arches for male and female Physical Education students at Al-Quds University (AQU) and Palestine Technical University – Kadoorie (PTUK), as a function of sitting and standing positions, as well as to identify the difference in the degree of curvature of the right and left feet due to sitting and standing positions attributed to the variables of university type, subjects’ gender and weight. Both measurement and analysis methods were used; the study sample consisted of (151) male and female students from both Physical Education Departments distributed as follows: (58) male and (45) female students from AQU and (48) female students from PTUK-Ramallah selected randomly. To answer the study questions, the scientific and statistical coefficients have been used. Our results showed that the differences in the left foot arch curvature for AQU students are at an average rate of (44.71%) compared to that of female students at PTUK by (49.78%) which is very close to the level before and in the absence of statistically significant differences at the level of significance (0.05≥α) in difference of degree of curvature of the right and the left feet from the two positions between students at Physical Education Departments attributed to the institution, gender and weight. The researchers recommend conducting a footprint examination for all students as a requirement to join the physical education departments and not to rely on the naked eye as an evaluation tool, since the height of the feet arches does not mean that student is fit to join the physical education program. It is possible that the height of the arches exceeds the normal limit and therefore will be a disorder similar to flat foot

Changes of Anterior Chamber Angle Parameters and Its Effect on Arch Height after ICL V4c Surgery

Changes of Anterior Chamber Angle Parameters and Its Effect on Arch Height after ICL V4c Surgery

Characteristics and Evolution of Tunnel Collapse in Fully-Weathered Coastal Red Sandstone Strata

Xu, H.; Shao, Z.; Chen, C.; Wang, Z.; Cai, L.; Li, Z., and Huang, C., 2022. Characteristics and evolution of tunnel collapse in fully-weathered coastal red sandstone strata. Journal of Coastal Research, 38(2), 289–301. Coconut Creek (Florida), ISSN 0749-0208. Understanding characteristics of tunnel collapse and its evolution is the premise of effective prevention and control. Fully-weathered coastal red sandstone is widely distributed in coastal areas, and the characteristics of tunnel collapse under this stratum are not clear. This paper studies characteristics of tunnel collapse and its evolution by conducting a model test of tunnel excavation in fully-weathered coastal red sandstone with digital image processing, where the whole process of rock mass failure, displacement, and strain variations are studied. The results show that: (1) the instability failure of the fully-weathered coastal red sandstone rock mass is a progressive process under the load. Three major collapses occur consecutively, where the first and the second start at the arch foot and arch waist, respectively; both manifested as cracks developing upward to the middle until the cracks penetrate. The third is mainly manifested as the collapse of rock mass block above the tunnel crown. (2) The displacement and shear strain around the tunnel increase first with the load and then stabilize. The vertical displacement is more significant than the horizontal displacement. Tunnel crown is where the vertical displacement increases the fastest and accumulates the most, which directly threatens the rock mass stability and thus deserves special attention. The arch waist has the most intense change of shear strain. (3) All three collapses end up forming a stable balanced arch. The three collapses show the evolution that the foot of the balanced arch gradually moves horizontally outward, and the height of the balanced arch gradually expands upward. The shape of the balanced arch can be well fitted by a parabolic function. Practical suggestions on tunnel collapse prevention and control of fully-weathered coastal red sandstone are also put forward.

Differences in Foot Characteristics Between Bharatanatyam Dancers and Age-Matched Non-Dancers.

The ankle-foot complex is the third most common site of pain in Indian dancers. In Bharatanatyam dance, rhythmic stamping performed barefoot at varying speeds may influence the height of the medial longitudinal arch, causing structural alteration of the ankle-foot complex. As little information is available on the ankle-foot complex of Bharatanatyam dancers, the present study was conducted to test the hypothesis that foot characteristics of Bharatanatyam dancers differ from those of non-dancers. Female professional Bharatanatyam dancers (n=21), aged 18-30 years, with a minimum of 8 years of performance experience after completing formal dance training, and 21 control non-dancers participated in this study. Physical foot examination included navicular drop test and Feiss line. Foot geometry and pedobarography were recorded as participants walked barefoot at self-selected walking pace over a pressure-platform. An average of five gait cycles was computed to analyse maximum peak pressure (MPP), pressure time integral, contact time, and foot geometry of the midfoot, forefoot, great toe, and second to fifth toes. Analysis of covariance was performed for intergroup comparison of all variables with gait speed as a covariate. During walking, dancers presented a higher medial-longitudinal-arch, wider midfoot, and wider forefoot (cm) (p<0.001), indicating an over-pronated foot due to lower medial longitudinal arch height. Total plantar peak pressure (kPa) was 37% higher among dancers, whereas MPP was 24% higher on midfoot and 13% higher on forefoot, indicating greater plantar loading during walking. Greater plantar loading and an over-pronated foot during the most commonly performed weight-bearing activity of daily living (e.g., walking) explain the common prevalence of ankle and foot pain among dancers. These findings will inform clinicians and Bharatanatyam dancers on dancer's foot function and guide strategies for prevention and management of foot pain.

Comparison of Leg Muscle Activity During Level and Uphill Walking in Individuals with Flat Foot and Normal Foot: A Cross-Sectional Study

Abstract Introduction. Arches of the foot play a significant role in lower limb function and impairments in the arches are correlated to increased injury risk. The aim of this study was to identify the difference in muscles activity in individuals with a flat foot as compared to those with normal foot arch using surface electromyography (sEMG) while walking on at different speeds and gradients (slope of the treadmill). Material and Methods. Sixty healthy subjects were recruited by convenience sampling method and equally divided into two groups: short arch group (n = 30) and normal arch group (n = 30) by measuring arch height. All the subjects were made to walk on a treadmill at varying speeds (2.7, 4.5, and 6.3 km/h) and gradients (0%, 3%, 6% and 9%). The sEMG activity was recorded for medial gastrocnemius (GM) muscle and peroneus longus (PL) muscle while walking on the treadmill. Results. 2 x 3 x 4 split-plot ANOVA revealed a significant group effect for GM activity (p &lt; 0.001), whereas PL activity was not able to show a significant group effect (p = 0.109). Increasing speeds led to a significant difference in the sEMG activity of PL and GM muscles (p &lt; 0.001) in the two groups. Increasing gradient of treadmill also showed a significant difference in the sEMG activity in the two groups for PL and GM muscle (p &lt; 0.05). Conclusions. The findings of this study demonstrated that subjects with flat feet had a lesser activation in PL muscles as compared to subjects with normal foot curvature. Therefore, it is necessary to incorporate strategies to improve the strength of these muscles to improve the arches of the foot.

Novel values in the radiographic diagnosis of ligamentous Lisfranc injuries

BackgroundLigamentous Lisfranc instability is commonly missed on unilateral radiographs. However, measurement protocols for bilateral weightbearing radiographs have not been standardized. The primary aim of this study was to investigate the optimal cut-off values for diagnosing Lisfranc instability by evaluating the side-to-side differences of preoperative bilateral weightbearing radiographs among patients with surgically-confirmed ligamentous Lisfranc instability. A secondary aim was to investigate whether the midfoot measurements for detecting Lisfranc injury could also be used in patients with a pre-existing bilateral Hallux Valgus (HV) deformity by evaluating whether the Lisfranc measurements could be affected by a foot deformity as HV. Patients and methodsPatients who underwent surgical repair of ligamentous Lisfranc instability, as well as a separate cohort with bilateral hallux valgus deformity, were included in this multicenter retrospective cohort study. A standardized radiographic measurement protocol was used to assess the midfoot and a receiver operator correlation (ROC) analysis was used to identify the optimal cut-off value for measurements. Interclass Correlation (ICC) scores were calculated to assess the interrater reliability of the Lisfranc area measurement. ResultsForty-seven patients were included in the Lisfranc group with a mean age of 33 (± 15) years and 25 patients were included in the HV group with a mean age of 51 (± 15) years. For the Lisfranc group, measurements that demonstrated a significant side-to-side difference included; increased C1M2 diastasis of 2.4 mm (± 1.4, P<0.001), increased C1M2 surface area of 24 mm2 (± 15, P<0.001), C2M2 malignment by 1.7 mm (± 1.2, P<0.001), second tarsometatarsal joint dorsal step-off sign by 0.8 mm (± 0.7, P<0.001), and arch height by 2.5 mm (± 6.4, P<0.048), all greater on the injured side. In the HV group, side-to-side measurements were not significantly different. There was no significant difference comparing the M1M2 measurement in the HV group with the injured (P = 0.16) or uninjured (P = 0.08) foot in the Lisfranc group. The optimal cut-off points were between the injured and uninjured foot in the Lisfranc group were 2.1 mm for C1M2 diastasis, 0.7 mm for the C2M2 alignment, and 30 mm2 for the C1M2 surface area. The ICC-score for the second C1M2 area measurement was 0.88. ConclusionBilateral foot weightbearing radiographs can effectively diagnose ligamentous Lisfranc instability using a standardized measurement protocol. Malalignment of the medial aspect of the second metatarsal base ≥0.3 mm relatively to the intermediate cuneiform offers a high sensitivity, and distance ≥2.1 mm between the second metatarsal base and the medial cuneiform has a high specificity. Intermetatarsal distance between the first and second metatarsal base has a low sensitivity and specificity and should not be used in solitary for diagnosis. Level of evidenceLevel III, retrospective comparative study

The influence of age and gender on normalized foot arch height of Korean children and adolescents: a cross-sectional study

Both the non-normalized and normalized arch height have been used to compare foot arch height among children. This study measured changes in foot dimensions, including length and the non-normalized and normalized arch height, among children and adolescents aged 8–19 years. Three-dimensional scanning data of 1451 children and adolescents were obtained. Four normalized arch height indices were calculated: the navicular height/total foot length, navicular height/instep length, instep height/total foot length and instep height/instep length. The current study found a significant positive relationship between foot length and non-normalized arch height. The normalized arch height increased linearly up to the age of 16 years. The proportion of pes planus also decreased with age. Current findings shed light on normative foot development in children and adolescents.

Foot morphology influences the change in arch index between standing and walking conditions.

Human foot morphology has been of interest to anatomists, clinicians, and paleontologists for a century due to its importance in bipedal walking. Foot shape changes as forces move through it from the body to the substrate. Although the arch of the foot has been extensively evaluated, the role of foot morphology in the change of the arch height in walking is less explored. To remedy this lacuna, the Arch Indices (AIs) of the left and right feet of 77 people were calculated in double and single stance standing and walking (dynamic) conditions. The feet were categorized into clinical foot types (cavus, normal, planus). The change in static AI between double and single stance was used to predict dynamic AI and the difference between predicted and observed dynamic AI was examined. As expected, AIs increased (i.e., arch height decreased) with increasing load on the foot for the entire sample and each foot type (p's&gt;.001), but the ability of change in static AIs to predict dynamic AI varied among foot types, implicating the possibility of variability in foot mechanics among foot types. While planus feet change stiffness during walking, presumably due to muscular action, cavus feet are more variable in their response to load. Static and dynamic AIs are effective in reflecting the changes in foot stiffness that occur in walking and future work should examine the role of extrinsic muscle activation in this stiffness change.

An Iterative Computing Method for Load Effect of Bidirectional Reinforced Embankment

Bidirectional reinforced embankment (BRE) technology, pile supporting in vertical and geosynthetic reinforcement in horizontal, has been widely adopted in engineering practice to control total and/or differential settlement. In design, the load distribution of BRE is essential for determining pile size (i.e., diameter and length), pile spacing, pile cap details (if any), and properties of geosynthetic reinforcement, et al. Several methods have been proposed in previous studies to investigate the load bearing mechanism in the BRE platform. However, resistance of foundation soil is typically neglected, which implies that the load on piles would be overestimated if the resistance of foundation soil is neglected or over weakened. The reason for this overestimation is that larger geosynthetic deflection would be expected without the reaction of foundation soil, which would cause a more significant soil arching and thus more load would be transferred to piles. To minimize this overestimation, a method for analyzing load transfer mechanism in the BRE was proposed, considering the subsoil resistance as well as the existence of neutral plane (i.e., zero skin friction). An equal settlement was assumed for soils at the embankment bottom and the foundation top. The iteration process was adopted to solve equations to determine the load shared by piles and soils. In derivation, the soil arch height in the embankment was calculated instead of being assumed in existing methods. A flow chart was developed to solve equations of the proposed method and two case histories from literatures were used to compose the rationality verification. Compared with the field measurement and numerical calculation, this study can be more effective in calculating loads shared by piles and soils in the BRE for the working condition with better pile end bearing stratum.

Configuration Design and Dynamic Characteristics Analysis of Spacecraft Membrane Sunshield.

To meet the needs of large space telescopes, such as light weight, high folding ratio, and low manufacturing cost, a flexible deployable regular hexagonal membrane sunshield is proposed in this paper. Firstly, the dynamic equation of the membrane plane is established by the micro-element method. Then, the response surface method is used to obtain the mathematical model of the fundamental frequency of the membrane sunshield. The factors influencing this model, such as the corner pulling force, the effective circle radius, and the edge arch height, are analyzed. By combining the formula of the fundamental frequency of the membrane sunshield and the effective area ratio of the sunshield, the multi-objective optimization function of the fundamental frequency of the membrane sunshield is obtained. A scaled-down experimental prototype of the membrane sunshield is built, and the modal test is performed on the thin membrane plane with a circular fixed boundary in the middle. Comparing the experimental results with the finite element simulation results, the mode shape and the fundamental frequency are highly consistent. This proves that the model can be used to solve the fundamental frequency of the membrane sunshield under the same boundary.

Effect of Longitudinal and Transverse Foot Arch on the Position of the Hallux and Fifth Toe in Preschool Children in the Light of Regression Analysis.

The aim of the study was to analyze the development of foot structure and the impact of longitudinal and transverse arching of the foot on the position of the hallux and fifth toe in preschool children. The study was carried out among 200 children aged 6 (100 G, 100 B). The research tool was the podoscope CQ-ST. The collected research results were analyzed with the use of the Mann–Whitney U test, Pearson Chi-square test and regression analysis. A statistically significant influence of the heel angle on the value of the varus angle of the fifth toe of the right (girls: p = 0.032; boys: p = 0.001) and left foot (girls: p = 0.004; boys: p = 0.005) was found. Boys’ feet are longer and wider than girls’ feet; moreover, they have a lower longitudinal arch. The frequency of longitudinal and transverse arch deformities of the feet, as well as valgus of the hallux and varus of the fifth toe do not depend on gender. In both sexes, decreasing the transverse arch of the foot has an influence on the severity of varus of the fifth toe. Changes in the height of the longitudinal foot arch does not affect the position of the hallux and fifth toe.

Three-Dimensional Carpal Arch Morphology Using Robot-Assisted Ultrasonography.

The morphology of the carpal arch implicates the available space for the median nerve within the carpal tunnel. The purposes of this study were to 1) reconstruct the three-dimensional (3D) carpal arch by robot-assisted ultrasonography with a linear array transducer using cadaveric hands, and 2) investigate the 3D morphological properties of the carpal arch. An ultrasound probe with two-dimensional (2D) linear array was integrated on a robotic arm and maneuvered over the cadaveric carpal tunnels to scan the entire transverse carpal ligament and its osseous attachments to carpal bones. The acquired series of 2D ultrasound images together with robot positioning were utilized to reconstruct the 3D carpal arch for morphometric analyses. Total carpal arch volume was 1099.4 ± 163.2 mm3 with the distal, middle, and proximal regions contributing 18.2 ± 1.5%, 32.7 ± 1.2%, and 49.1 ± 2.3%, respectively. The ligament surface area was 420.1 ± 63.9 mm2. The carpal arch width, height, curvature, length, area, and palmar bowing index progressively increased from the distal to proximal locations within the tunnel (p < 0.01). The incorporation of the robot technology with the ultrasound system advanced the applications of traditional 2D ultrasound imaging for a 3D carpal arch reconstruction, allowing for comprehensive morphological assessment of the carpal arch. The developed workflow can be used for the reconstruction and analysis of other anatomical features in vivo.

Elliptical-Shaped Fresnel Lens Design through Gaussian Source Distribution

A novel three-dimensional elliptical-shaped Fresnel lens (ESFL) analytical model is presented to evaluate and maximize the solar energy concentration of Fresnel-lens-based solar concentrators. AutoCAD, Zemax and Ansys software were used for the ESFL design, performance evaluation and temperature calculation, respectively. Contrary to the previous modeling processes, based on the edge-ray principle with an acceptance half-angle of ±0.27° as the key defining parameter, the present model uses, instead, a Gaussian distribution to define the solar source in Zemax. The results were validated through the numerical analysis of published experimental data from a flat Fresnel lens. An in-depth study of the influence of several ESFL factors, such as focal length, arch height and aspect ratio, on its output performance is carried out. Moreover, the evaluation of the ESFL output performance as a function of the number/size of the grooves is also analyzed. Compared to the typical 1–16 grooves per millimeter reported in the previous literature, this mathematical parametric modeling allowed a substantial reduction in grooves/mm to 0.3–0.4, which may enable an easy mass production of ESFL. The concentrated solar distribution of the optimal ESFL configuration was then compared to that of the best flat Fresnel lens configuration, under the same focusing conditions. Due to the elliptical shape of the lens, the chromatic aberration effect was largely reduced, resulting in higher concentrated solar flux and temperature. Over 2360 K and 1360 K maximum temperatures were found for ESFL and flat Fresnel lenses, respectively, demonstrating the great potential of the three-dimensional curved-shaped Fresnel lens on renewable solar energy applications that require high concentrations of solar fluxes and temperatures.

Foot arch height, toe flexor strength, and dynamic balance ability in collegiate female dancers and non-dancers.

[Purpose] To characterize the foot arch height, toe flexor strength, and dynamic balance ability of collegiate female dancers and age-matched non-dancers. [Participants and Methods] This study included 20 healthy college-aged female dancers (21.6 ± 0.8 years) and 20 age-matched females (19.7 ± 1.0 years) with no previous experience in sports as non-dancers. Foot arch height was determined by measuring the height of the navicular tuberosity in the standing position using a ruler. Toe flexor strength was measured while seated on a chair using a toe grip dynamometer. Dynamic balance ability was evaluated based on the reach distance measured using a professional Y-balance test kit. [Results] The collegiate dancers had higher foot arches, greater toe flexor strength, and longer Y-balance test reach distance than the non-dancers. [Conclusion] The foot arch height, toe flexor strength, and dynamic balance ability of collegiate female dancers were adapted through years of training and were superior to those of non-dancers.