Dynamic Footprint Research Articles

Foot Progression Angle in Relation to Spatiotemporal Parameters of Gait in Children with Cerebral Palsy

OBJECTIVE: This study assessed the difference in the foot progression angle and measure spatiotemporal parameters of gait of children with diplegic cerebral palsy and to examine the relation among foot progression angle of right and left lower limb and spatiotemporal parameters of gait. DESIGN: Cross-sectional and Correlation study. SUBJECTS: Sixty children with spastic diplegia, aged 5 to 8 years. The participants were categorized into 3 age groups of equivalent number: group A (5 to 6 years), group B (6 to 7 years), as well as group C (7 to 8 years). METHODS: Foot progression angle and spatiotemporal parameters of the gait for both feet were evaluated utilizing a dynamic footprint. RESULTS: a moderate negative significant correlation was noted among left FPA and right step length, and right stride length. There was moderate positive significant correlation among left FPA and cadence . A weak non-significant correlation was observed among right and left FPA and gait parameters among three groups. CONCLUSION: foot progression angle assessment and spatiotemporal measurements and the correlation among them can give objective and quantitative data that could be utilized in rehabilitation and clinical evaluations to identify functional deficiencies.

A preliminary study on the stability of bare footprint linear measurements in four motion states

In some crime scenes, there may be bare footprints. Analyzing and testing the linear measurements of bare footprints in crime scenes can play an important role in personal analysis and individual identification. However, the linear measurements of bare footprints may be influenced by different motion states, leading to changes in length and width or even significant deviations. Previous studies focused on the linear differences between static and dynamic footprints, and failed to take the speed factor into consideration. This paper studied the stability and change regularities of the linear measurements of bare footprints in four different motion states: standing, normal walking, fast walking and trotting. Dust footprints of the right feet were collected from 80 healthy young adults under these four motion states. Seven linear measurements were obtained for each footprint using the Reel method, totaling 2240 data sets. One-way repeated measures ANOVA was used to assess the measurement variations across the four states. The results showed that there were statistically significant variances in the length measurements (A1-A5) between the standing state and other motion states, whereas no statistically significant variances were observed between the three dynamic states. It was found that the mean values of the five length measurements (A1–A5) increased from static to dynamic state, and then gradually decreased slightly as the walking speed increased. Additionally, no significant differences were found in the two width measurements (MPJ Width and Calc Width) between the four motion states. As a preliminary study, this study can provide a reference for the analysis of bare footprints in different motion states extracted from crime scenes.

Static and dynamic footprint analysis among young indigenous Izzi male adults residing in Abakaliki metropolis.

Static and dynamic footprint analysis among young indigenous Izzi male adults residing in Abakaliki metropolis.

The importance of assessing the ghosting phenomenon in dynamic footprints when estimating stature – Forensic implications

In cases where multiple footprints are found at a crime scene, it is unusual that all are static, and some are likely dynamic. Depending on how the footprint was made, we distinguish between dynamic and static footprints. A distinguishing feature that has only recently been associated with dynamic footprints is the fact that dynamic footprints differ from static footprints by the presence of additional markings around the back of the heel and the tops of the toe prints, the so-called ghosting phenomenon. The present study aims to analyse the ghosting phenomenon on dynamic footprints – its occurrence in relation to sex, laterality, and different areas of footprints as well as length features. Additionally, it aims to investigate the assessment of the ghosting phenomenon on dynamic footprints when estimating stature for biological profiling in the forensic field. The study sample comprised of 170 young adults aged 18 – 30 years of both biological sexes. Stature was measured and dynamic footprints were obtained where the ghosting phenomenon was analysed together with length measurements of the same footprint with and without ghosting. In the first and second toes of footprints, the ghosting phenomenon occurred most frequently in both sexes and in the sex-mixed group. Sex differences were not significant in ghosting occurrence on right and left footprints (p > 0.05), except for the area of the left fifth toe (p = 0.045). All the footprints’ lengths with ghosting were significantly higher (p < 0.001) than those without ghosting. Statures calculated from footprint length measurements with ghosting predicted stature more accurately than statures calculated from the same footprint length measurements without ghosting. In the case of finding dynamic footprints at crime scenes, it is necessary to correctly identify and evaluate ghosting of the footprint. This comparison can be helpful in interpreting how ghosting should be taken into account when estimating a person's stature.

Static and dynamic plantar foot shape following long-term use of military boots

Foot structure can be influenced by various factors, such as footwear, body weight and physical activity. A change in foot structure can alter shock absorption and force transition. The main objective of this study is to investigate the effect of the long-term use of military boots on foot shape parameters. Thirty military and thirty non-military subjects participated in this case-control study. All participants had been regularly wearing military boots for the past 12 years. After introducing the experiment, static and dynamic footprints were recorded via paper and ink while standing and walking. The footprints were analysed using ImageJ software to extract foot width indices, area indices, truncated arch index, footprint index and arch angle index. The findings indicated no significant difference in comparison static and dynamic variables in the military and non-military groups (p ≥ 0.05). However, there was a significant difference between the two groups in both static (midfoot area, arch index (AI), truncated arch index, footprint index and arch angle index) and dynamic (midfoot width, Staheli Index (SAI), truncated arch index and arch angle index) conditions, when static and dynamic variable were compared (p &lt; 0.05). Findings revealed the military personnel have low arch, making them susceptible to musculoskeletal disorders. To mitigate this risk, it is recommended that military boots be reassessed or that insoles be used. Furthermore, it is suggested that military boots be limited to specific activities and fewer hours of usage to avoid potential health issues.

Dynamic Footprints of the Specific Artificial Spin Ice Microstate on Its Spin Waves

We present a micromagnetic investigation of the spin dynamics at remanence (zero applied field) in a periodic square artificial spin ice (ASI) prepared four different microstates (i.e., with zero, two or four magnetic charges at the vertex). The ASI elements consist of permalloy elliptical dots with a fixed long axis, and a variable width and interdot separation. For each vertex configuration, we compute the equilibrium ground state at zero applied field by relaxing a previously set magnetic configuration (microstate). After the excitation of such ground state, we perform a Fourier analysis obtaining frequency spectra and space phase profiles. We discuss the behavior of the spectra in changing the system’s microstate and geometry, with reference to the spin mode space profiles, magnetization configuration, and effective internal field. Our results draw a correlation between ASI macrospin orientation at vertex and a few important dynamic properties like a phase-shift in the mode profiles or the frequency gap between the edge and fundamental modes. We suggest a few specific experiments to validate of our predictions, as well as applications in the field of interferometric magnonic devices. We believe that our results can help, from the fabrication stage, in tailoring the appropriate ASI geometry for specific application purposes.

Ghosting phenomenon in static and dynamic footprints in India and the United States

Ghosting is the phenomenon that exists when a footprint has a lighter area around the tip of one or more toes or a shadow-like area at the back of the heel. To date, ghosting has been considered primarily a finding of dynamic (walking) footprints, rather than static (standing) footprints. The prevalence of ghosting in static footprints is unknown, and research on its presence in static and dynamic footprints from the same participant is sparse, as are studies on its occurrence in different geographic populations. This study is among the first to evaluate the occurrence of ghosting in the static and dynamic footprints from a particular individual with participants in two geographic populations.A combination of both inkless and ink footprint collection systems were used to obtain a total of 206 bare footprints from 103 adult participants from the United States and India. The data comprised 103 static and 103 dynamic footprints.Ghosting occurred significantly in static footprints, though less frequently than in dynamic footprints. Ghosting in static footprints was seen most often at the first toe, followed by the third and second respectively. This aspect appeared least at the heel. In dynamic footprints, it occurred most at the first toe, followed by the second and fourth toes, and then the third toe and the heel. The prevalence of ghosting in footprints from the United States and India differed in their locations, notably at the first and second toes in the static footprints and at the heel in the dynamic footprints.

Altitude control of a quadcopter using interval type-2 fuzzy controller with dynamic footprint of uncertainty

Footprint of uncertainty (FOU) characteristics of interval type-2 membership functions (IT2-MFs) play an important role in the performance and robustness of interval type-2 fuzzy controllers (IT2-FCs). In literature, fixed FOU structures are used in almost all IT2-FC designs. In this study, an IT2-FC with dynamic FOU is proposed to provide high performance and robustness in the altitude control of a quadcopter. A proportional–derivative (PD) type FC with Takagi–Sugeno rule structure is used in the design procedure of the proposed controller. Additionally, input variables (error and derivative of error) are defined by using triangular IT2-MFs. To provide a dynamic FOU structure, the height of the lower MF (LMF) of each interval type-2 fuzzy set is defined as a function of the system error. In this way, FOU levels of IT2-MFs are adjusted dynamically since the height value of the LMF directly determines the FOU level of the IT2-MF. To evaluate the effectiveness of the proposed controller, comparison studies are performed under different conditions, including unmodeled measurement noises, an external disturbance, and a system parameter uncertainty. A classical PD, a type-1 fuzzy PD, and an interval type-2 fuzzy PD with fixed FOU controllers are used in the comparisons. The comparison results demonstrate that the proposed interval type-2 fuzzy PD controller with dynamic FOU exhibits better performance and more robustness than the other controllers.

Upscaling Methane Flux From Plot Level to Eddy Covariance Tower Domains in Five Alaskan Tundra Ecosystems

Spatial heterogeneity in methane (CH4) flux requires a reliable upscaling approach to reach accurate regional CH4 budgets in the Arctic tundra. In this study, we combined the CLM-Microbe model with three footprint algorithms to scale up CH4 flux from a plot level to eddy covariance (EC) tower domains (200 m × 200 m) in the Alaska North Slope, for three sites in Utqiaġvik (US-Beo, US-Bes, and US-Brw), one in Atqasuk (US-Atq) and one in Ivotuk (US-Ivo), for a period of 2013–2015. Three footprint algorithms were the homogenous footprint (HF) that assumes even contribution of all grid cells, the gradient footprint (GF) that assumes gradually declining contribution from center grid cells to edges, and the dynamic footprint (DF) that considers the impacts of wind and heterogeneity of land surface. Simulated annual CH4 flux was highly consistent with the EC measurements at US-Beo and US-Bes. In contrast, flux was overestimated at US-Brw, US-Atq, and US-Ivo due to the higher simulated CH4 flux in early growing seasons. The simulated monthly CH4 flux was consistent with EC measurements but with different accuracies among footprint algorithms. At US-Bes in September 2013, RMSE and NNSE were 0.002 μmol m−2 s−1 and 0.782 using the DF algorithm, but 0.007 μmol m−2 s−1 and 0.758 using HF and 0.007 μmol m−2 s−1 and 0.765 using GF, respectively. DF algorithm performed better than the HF and GF algorithms in capturing the temporal variation in daily CH4 flux each month, while the model accuracy was similar among the three algorithms due to flat landscapes. Temporal variations in CH4 flux during 2013–2015 were predominately explained by air temperature (67–74%), followed by precipitation (22–36%). Spatial heterogeneities in vegetation fraction and elevation dominated the spatial variations in CH4 flux for all five tower domains despite relatively weak differences in simulated CH4 flux among three footprint algorithms. The CLM-Microbe model can simulate CH4 flux at both plot and landscape scales at a high temporal resolution, which should be applied to other landscapes. Integrating land surface models with an appropriate algorithm provides a powerful tool for upscaling CH4 flux in terrestrial ecosystems.

Regime identification for stratified wakes from limited measurements: A library-based sparse regression formulation

All objects moving through the atmosphere or the ocean leave behind a fluid dynamic footprint known as a wake. The patterns in this wake are often long-lasting and, moreover, they can contain information about the object that created the wake, e.g., size and speed. In this study, we develop a framework that can identify such information (the ``regime'') based on limited measurements in the wake. Tests using data from simulations as well as laboratory experiments show that this approach holds promise in the development of automated data-driven fluid pattern classifiers.

Estimation of stature and body weight from static and dynamic footprints – Forensic implications and validity of non-colouring cream method

In the present study, the metric properties of dynamic footprints were analysed using non-colouring method in relation with body parameters and compared with static footprint measurements. The results of the study provide a better understanding of the relationship between static and dynamic footprints, which may be useful for biological profiling that allows more accurate identification. Stature, body weight, five length and two width parameters of dynamic (walking) footprints of young Slovak adults (65 females and 68 males) were analysed. Pearson correlation coefficients were calculated and equations for prediction of stature and body weight by linear regression analysis and multiple regression analysis were developed. Intersex differences were confirmed for all parameters and bilateral for some. Statistically significant differences were found in all measurements (p-value>0.05), except for the width of the standing and walking footprint in the mixed group. A positive correlation was found between the selected footprint diameters with stature (max - r = 0.82) and body weight (max - r = 0.70). Stature could be calculated with an accuracy of up to 4.40 cm and body weight with an accuracy of up to 9.56 kg. The results of the present study show that selected measurements of dynamic footprints correlate with stature and body weight. These results could be used in biological profiling in the medical and forensic fields.

Kindlin-3 recruitment to the plasma membrane precedes high-affinity β2-integrin and neutrophil arrest from rolling

AbstractIntegrin-mediated neutrophil adhesion starts by arrest from rolling. Activation of integrins involves conformational changes from an inactive, bent conformation to an extended conformation (E+) with high affinity for ligand binding (H+). The cytoplasmic protein kindlin-3 is necessary for leukocyte adhesion; mutations of kindlin-3 cause leukocyte adhesion deficiency type 3. Kindlin-3 binds the β2-integrin cytoplasmic tail at a site distinct from talin-1, but the molecular mechanism by which kindlin-3 activates β2-integrins is unknown. In this study, we measured the spatiotemporal dynamics of kindlin-3 and β2-integrin conformation changes during neutrophil and HL-60 cell rolling and arrest under flow. Using high-resolution quantitative dynamic footprinting microscopy and kindlin-3–fluorescent protein (FP) fusion proteins, we found that kindlin-3 was recruited to the plasma membrane in response to interleukin-8 (IL-8) before induction of the H+ β2-integrin conformation. Intravital imaging revealed that EGFP-kindlin-3–reconstituted, kindlin-3–knockout neutrophils arrest in vivo in response to CXCL1. EGFP-kindlin-3 in primary mouse neutrophils was also recruited to the plasma membrane before arrest. Upon arrest, we found small clusters of high-affinity β2-integrin molecules within large areas of membrane-proximal kindlin-3 FP. Deletion of kindlin-3 or its pleckstrin homology (PH) domain in neutrophil-like HL-60 cells completely abolished H+ β2-integrin induction. IL-8 also triggered recruitment of the isolated kindlin-3 PH domain to the plasma membrane before arrest. In summary, we showed that the kindlin-3 PH domain is necessary for recruitment to the plasma membrane, where full-length kindlin-3 is indispensable for the induction of high-affinity β2-integrin.

Optimized Laboratory Test Condition to Predict Tire Tread Wear

Laboratory test condition to predict tire tread wear was discussed, using the FPS wear test equipment manufactured by Ueshima Seisakusho Co. Ltd. Sample load was determined based on the sample dynamic footprint and inflation pressure of different tire groups. Most tire groups evaluate wear rate by volume loss per distance with the exception of giant mining tires which evaluate volume loss per hours. In light of truck, bus and passenger tires, the laboratory test in the present paper employed the volume loss per distance. In such case, slip ratio correlated with wear rate better than slip speed. The surface of the worn sample and wear debris indicated that the laboratory wear mechanism was identical to road wear mechanism which was considered plastic wear (P-wear) instead of the conventional elastic wear (E-wear).

Relevant out-of-time-order correlator operators: Footprints of the classical dynamics.

The out-of-time-order correlator (OTOC) has recently become relevant in different areas where it has been linked to scrambling of quantum information and entanglement. It has also been proposed as a good indicator of quantum complexity. In this sense, the OTOC-RE theorem relates the OTOCs summed over a complete basis of operators to the second Renyi entropy. Here we have studied the OTOC-RE correspondence on physically meaningful bases like the ones constructed with the Pauli, reflection, and translation operators. The evolution is given by a paradigmatic bi-partite system consisting of two perturbed and coupled Arnold cat maps with different dynamics. We show that the sum over a small set of relevant operators is enough in order to obtain a very good approximation for the entropy and, hence, to reveal the character of the dynamics. In turn, this provides us with an alternative natural indicator of complexity, i.e., the scaling of the number of relevant operators with time. When represented in phase space, each one of these sets reveals the classical dynamical footprints with different depth according to the chosen basis.

Clinical Assessment of the Medial Longitudinal Arch in Children: Rater Agreement and Relationship to Objective Foot Arch Measurements

The purpose of this study was to (1) investigate the agreement among clinical experts regarding the classification of the medial longitudinal arch in children and to (2) examine the relationship between the expert ratings and the static and dynamic foot arch measurements. Eleven foot experts were asked to identify foot arches of seventy-four children (mean ± SD age of 9.0 ± 1.81 years) using three categories (low, normal, and high arch). Additionally, dynamic footprint data of all children were captured with a pedobarographic platform. For static arch measurements, a specially constructed caliper was used to assess heel-to-toe length and dorsum height. Agreement among raters was determined using the kappa statistic. For comparisons between clinical rating and diagnostic systems, receiver operating characteristic (ROC) curves and ordinal logistic regression were calculated. The combined kappa score for all three arch types (0.422, 32.8%) shows borderline moderate agreement between raters. Area under the curves (AUC) values of the ROC curves ranging from 0.48 to 0.68 show poor relationship between quantitative and qualitative arch height measurements. The highest agreement was found for the dynamic arch index and foot experts’ ratings for low arched vs non-low arched feet (AUC = 0.68) and normal vs low arched feet (AUC = 0.67). The results of this study showed borderline moderate agreement among clinical experts in the clinical assessment of the medial longitudinal plantar arch in children. Also, only a poor relationship between the clinical foot arch assessments and the static and dynamic foot measurements was revealed. Further research is necessary to establish an accurate and consistent diagnostic system for the measurement of the medial longitudinal arch in children.

The contact area of static and dynamic footprints: Forensic implications

When found at crime scenes, footprints may be evidentially valuable and can assist with the identity of a perpetrator based on their features and/or measurements. Footprints can be either static (made while standing) or dynamic (made while walking). While extensive research has been performed on the linear measurements obtained from static and dynamic footprints, research on the comparisons between the contact area of static and dynamic footprints in the forensic context are limited. The present study compares the contact area of static and dynamic bare footprints to determine if statistically significant differences exist between the two. Static and dynamic footprints were obtained from a sample of randomly-selected 461 Jatt Sikh adults (230 males and 231 females) of Indian origin between the ages of 19 and 32 years. The footprint contact area was calculated from each footprint (excluding the toes) using a PedoGRID® sheet. No statistically significant differences were observed between the contact area of static and dynamic footprints for each foot among males and females. However, statistically significant differences between both the sexes were found in the footprint contact areas of both footprint types. The right dynamic footprint contact area was found to be the most predictive measurement for classifying and estimating sex from a footprint’s contact area. The study has implications in the analysis of footprints recovered from crime scenes.

Prevalence and Related Factors of Flexible Flatfoot in School-Aged Children: A Cross-Sectional Study

Category:Other; Midfoot/ForefootIntroduction/Purpose:There is a greater prevalence of flexible flatfoot (FFF) among children; however, most of them are physiological, and the associated factors are still in debate. The purpose of current cross-sectional study was to investigate the FFF prevalence of 6 to 13 years Han nationality children in Northwest China; and to investigate the potential relative factors correlated with FFF.Methods:A total of 1,059 children aged from 6 to 13 years were included. Dynamic footprints according to FootScan system were collected from both feet. The relationship of FFF with age, gender, side, body mass index (BMI), foot length-width ratio (LWR), and contact area were investigated.Results:The percentage of FFF decreased from 39.5% at 6 years to 11.8% at 12 years, and reached a platform at 12 to 13 years. Overweight (OR 1.35, 95%CI 1.03-1.77) and obese (OR 2.43, 95%CI 1.81-3.26) showed positive correlation with percentage of FFF children; but only obese (OR 3.25, 95%CI 2.19-4.82) showed positive correlation in small age group (6 to 9 years). The mean LWR was larger in healthy children, and still larger in small and large age groups (P < 0.01). The mean midfoot contact area percentage was larger in FFF than healthy foot (P < 0.01). No correlation was found between FFF prevalence and gender or side.Conclusion:The prevalence of FFF decreases with age, and reached a platform at 12 to 13 years. The prevalence of FFF is positively correlated with increased BMI, especially in small aged children; and the prevalence of FFF is positively correlated with decreased LWR.

Dynamic energy and carbon footprints of urban transportation infrastructures: Differentiating between existing and newly-built assets

Transportation infrastructures play an important role in building energy-efficient and low-carbon cities. Yet, how existing and newly-built assets contribute differently to the footprints of transportation infrastructures is not clear. In this paper, we develop a life-cycle approach to quantify the energy and carbon footprints of urban transportation infrastructures over time, with a clear differentiation between existing and newly-built assets. Taking Guangzhou, China as a case study, we evaluate the dynamic footprints of various types of urban transportation infrastructure (roads, subway, and railway) across their life-cycle stages until 2017, and perform a scenario analysis to 2035 to explore future pathways of footprint mitigation. We find that the energy and carbon footprints of road assets built prior to 2005 are around 36 times higher than those of the subway and 5 times higher than those of the railway. However, this situation has begun to shift over 2006–2017 as the subway and railway have become more popular means of transportation and bigger contributors to the city’s energy and carbon footprints. The pace of technological advances in building transportation infrastructure needs to exceed that of the average urban economy to steadily reduce the energy and carbon footprints of the new projects planned. These findings offer a dynamic life-cycle approach and tool to evaluate long-term regulatory policies toward a more sustainable transportation infrastructure system in cities.

Chasing ghosts: An investigation of the ghosting phenomenon in footprints

Ghosting is a phenomenon that has been identified in dynamic (walking) footprints. There is sparse research on the occurrence of ghosting; however, due to the forensic value of footprints and their use in other scientific fields, the phenomenon of ghosting warrants further study. Ghosting can be used to determine if a footprint is static (standing) or dynamic, which can help forensic investigators create a sequence of events at a crime scene. Furthermore, this can help in footprint comparisons from this determination, as “like versus like” comparisons of dynamic or static footprints can be made. The purpose of this research was to determine the prevalence and locations of the ghosting phenomena in dynamic footprints.136 dynamic footprints from 68 volunteers were collected using an inkless collection system. Each footprint was visually inspected for ghosting as well as examined using software.Ghosting was present on at least one location in all footprints. The highest prevalence occurred at the tip of the great toe, followed by the second digit and the heel. To a lesser extent, ghosting appeared at the tips of the other three digits. Ghosting often occurred at two or more areas in a given footprint.

Kindlin-3 organizes a ring of clustered high affinity β2 integrins during human neutrophil spreading under flow

Abstract Neutrophils are vital for inflammation and immune defense. Dependent on β2 integrins, spherical neutrophils spread on vascular endothelium after arrest, which is critical for their recruitment from circulation to resist high shear flow and to initiate intravascular crawling. Here, we use high-resolution quantitative dynamic footprinting microscopy to monitor neutrophil spreading on a substrate of recombinant ICAM-1 and P-selectin under flow. A homogenous binding assay using the conformation-reporter antibodies mAb24 (reporting high-affinity β2, H+) and KIM127 (reporting extended β2, E+) showed three conformations of activated β2 integrins. E−H+ β2 integrins increased before E+H− and E+H+ conformations at the beginning of neutrophil spreading. Integrin extension depended on Syk-mediated integrin outside-in signaling. The ring of E−H+ and E+H+, but not E+H− β2 integrins was fully formed during late neutrophil spreading just before migration. Using kindlin-3-GFP fusion proteins, a ring of kindlin-3 was observed before the ring of H+ integrins appeared. These findings show spatially coordinated integrin activation during spreading. The previously unrecognized E−H+ conformation is the pioneer integrin for neutrophil spreading and appears to be organized by kindlin-3.