The Māori foot exhibits differences in plantar loading and midfoot morphology to the Caucasian foot

The question being addressed in the current study was whether the diabetic Māori foot was more or less prone to ulceration than the diabetic New Zealand Caucasian (NZC) foot. Harris mat and pedobarographic analyses were employed to assess static and dynamic foot morphology and plantar loading in 40 Māori and NZC diabetic and non-diabetic participants. Significantly higher peak pressures were exhibited by the diabetic Māori participants compared to their NZC peers at the central forefoot. Significantly higher static and dynamic arch index values and significantly higher sub-arch angle values were exhibited by the non-diabetic Māori participants compared to their NZC peers. The latter findings suggest that healthy Māori may have a predisposition towards having a flatter foot than healthy NZC, which may have footwear design implications.

Preliminary baropodometric analysis of young soccer players while walking: geometric morphometrics and comparative evaluation

AIM

The plantar support and its modifications are widely studied because of their bearing on posture. In particular, past studies have focused on the support modification during specific athletic tasks to highlight the eventual correlations between foot type and the most frequent sport injuries, due to intrinsic and extrinsic components that involve the structural and functional dynamics that act on the plantar vault during static and dynamic condition. These studies have been conducted by analyzing the morphological variation of the footprint during the performance.

METHODS

In the present study the variation in shape of the baropodometrical footprint of young soccer players, has been analyzed using geometric morphometrics. This approach permits a quantification of the morphological variation of the subjects using Cartesian coordinates placed at specific points on the footprint outline, and to correlate them with physical variables.

RESULTS

In the present study the young soccer players displayed a narrowing of the footprint due to a transversal variation on the isthmus, when compared to children of the same age who did not play soccer. These results suggest a physiological and biomechanical organization of the foot type in soccer due to the specific athletic tasks involved.

CONCLUSION

As the foot type, in sport, is strictly associated to recurrent injuries, the result obtained in this study should be considered as indicative for future analysis. In fact, a clear and univocal knowledge of this phenomenon would be useful in the planning of a training protocol to reduce the incidence of sport related injuries.

Hierarchical scale-based multiobject recognition of 3-D anatomical structures

Segmentation of anatomical structures from medical images is a challenging problem, which depends on the accurate recognition (localization) of anatomical structures prior to delineation. This study generalizes anatomy segmentation problem via attacking two major challenges: 1) automatically locating anatomical structures without doing search or optimization, and 2) automatically delineating the anatomical structures based on the located model assembly. For 1), we propose intensity weighted ball-scale object extraction concept to build a hierarchical transfer function from image space to object (shape) space such that anatomical structures in 3-D medical images can be recognized without the need to perform search or optimization. For 2), we integrate the graph-cut (GC) segmentation algorithm with prior shape model. This integrated segmentation framework is evaluated on clinical 3-D images consisting of a set of 20 abdominal CT scans. In addition, we use a set of 11 foot MR images to test the generalizability of our method to the different imaging modalities as well as robustness and accuracy of the proposed methodology. Since MR image intensities do not possess a tissue specific numeric meaning, we also explore the effects of intensity nonstandardness on anatomical object recognition. Experimental results indicate that: 1) effective recognition can make the delineation more accurate; 2) incorporating a large number of anatomical structures via a model assembly in the shape model improves the recognition and delineation accuracy dramatically; 3) ball-scale yields useful information about the relationship between the objects and the image; 4) intensity variation among scenes in an ensemble degrades object recognition performance.

Superhydrophobic gecko feet with high adhesive forces towards water and their bio-inspired materials

Functional integration is an inherent characteristic for multiscale structures of biological materials. In this contribution, we first investigate the liquid-solid adhesive forces between water droplets and superhydrophobic gecko feet using a high-sensitivity micro-electromechanical balance system. It was found, in addition to the well-known solid-solid adhesion, the gecko foot, with a multiscale structure, possesses both superhydrophobic functionality and a high adhesive force towards water. The origin of the high adhesive forces of gecko feet to water could be attributed to the high density nanopillars that contact the water. Inspired by this, polyimide films with gecko-like multiscale structures were constructed by using anodic aluminum oxide templates, exhibiting superhydrophobicity and a strong adhesive force towards water. The static water contact angle is larger than 150° and the adhesive force to water is about 66 μN. The resultant gecko-inspired polyimide film can be used as a "mechanical hand" to snatch micro-liter liquids. We expect this work will provide the inspiration to reveal the mechanism of the high-adhesive superhydrophobic of geckos and extend the practical applications of polyimide materials.

Bioinspired structured surfaces

Nature has evolved objects with desired functionality using commonly found materials. Nature capitalizes on hierarchical structures to achieve functionality. The understanding of the functions provided by objects and processes found in nature can guide us to produce nanomaterials, nanodevices, and processes with desirable functionality. Various natural objects which provide functionality of commercial interest have been characterized to understand how a natural object provides functionality. We have modeled and fabricated structures in the lab using nature's route and developed optimum structures. Once it is understood how nature does it, optimum structures have been fabricated using smart materials and fabrication techniques. This feature article provides an overview of four topics: Lotus effect, rose petal effect, gecko feet, and shark skin.

Flatfoot in children: anatomy of decision making

Concern about a child's foot posture is a common reason for frequent consultations for an array of health care professionals; sports medicine specialists are often the first to recognize and advise on foot pathology. In the decision making process, it is essential to distinguish between the different types of flatfoot deformity: paediatric or adult, congenital or acquired, flexible or rigid. Although flatfoot in children is a common finding, evidence for the techniques of the reliable and reproducible assessment of the foot posture is scant. This general review presents the factors involved in the forming and supporting of the foot arches, discusses the protocols useful in the evaluation of the foot posture, and indicates how to differentiate between flatfoot cases needing treatment and cases that need only reassurance.

Optimal principle of bone structure

Bone modeling and remodeling is an optimization process where no agreement has been reached regarding a unified theory or model. We measured 384 pieces of bone in vivo by 64-slice CT and discovered that the bone's center of mass approximately superposes its centroid of shape. This phenomenon indicates that the optimization process of non-homogeneous materials such as bone follows the same law of superposition of center of mass and centroid of shape as that of homogeneous materials. Based upon this principle, an index revealing the relationship between the center of mass and centroid of shape of the compact bone is proposed. Another index revealing the relationship between tissue density and distribution radius is followed. Applying these indexes to evaluate the strength of bone, we have some new findings.

Developmental differences in peripheral glabrous skin mechanosensory nerve receptive field and intracellular electrophysiologic properties: phenotypic characterization in infant and juvenile rats

Developmental differences in peripheral neuron characteristics and functionality exist. Direct measurement of active and passive electrophysiologic and receptive field characteristics of single mechanosensitive neurons in glabrous skin was performed and phenotypic characterization of fiber subtypes was applied to analyze developmental differences in peripheral mechanosensitive afferents. After Institutional approval, male Sprague-Dawley infant (P7: postnatal day 7) and juvenile (P28) rats were anesthetized and single cell intracellular electrophysiology was performed in the dorsal root ganglion (DRG) soma of mechanosensitive cells with receptive field (RF) in the glabrous skin of the hindpaw. Passive and active electrical properties of the cells and RF size and characteristics determined. Fiber subtype classification was performed and developmental differences in fiber subtype properties analyzed. RF size was smaller at P7 for both low and high threshold mechanoreceptor (LTMR and HTMR) with no differences between A- and C-HTMR (AHTMR and CHTMR). The RF size was also correlated to anatomic location on glabrous skin, toes having smaller RF. Conduction velocity (CV) was adequate at P28 for AHTMR and CHTMR classification, but not at P7. Only width of the action potential at half height (D50) was significantly different between HTMR at P7, while D50, CV and amplitude of the AP were significant for HTMR at P28. RF size is determined in part by the RF distribution of the peripheral neuron. Developmental differences in RF size occur with larger RF sizes occurring in younger animals. This is consistent with RF size differences determined by measuring RF in the spinal cord, except the peripheral RF is much smaller, more refined, and in some cases pinpoint. Developmental differences make CV alone unreliable for neuron classification. Utilizing integration of all measured parameters allows classification of neurons into subtypes even at the younger ages. This will prove important in understanding changes that occur in the peripheral sensory afferents in the face of ongoing development and injury early in life.

Multiscale phenomena related to diabetic foot

Diabetes is a group of metabolic diseases causing a system disorder, i.e.; it cannot be explained or understood by phenomena on single material scale. The diabetic foot is studied as flexible multibody structure by nonlinear finite element method. The physical and geometrical multiscale heterogeneity is solved by multilevel finite element approach. The diabetic tissue is described by internal coordinate's formalism, as complex multiscale process in tissue. The accompanying problem of the axisymetric wound healing is solved numerically. Some results related to foot deformity, stress and strain concentration and wound healing are presented.

Intra- and interobserver reliability of quantitative ultrasound measurement of the plantar fascia

PURPOSE

To determine intra- and interobserver reliability and measurement precision of sonographic assessment of plantar fascia thickness when using one, the mean of two, or the mean of three measurements.

METHODS

Two experienced observers scanned 20 healthy subjects twice with 60 minutes between test and retest. A GE LOGIQe ultrasound scanner was used in the study. The built-in software in the scanner was used to measure the thickness of the plantar fascia (PF). Reliability was calculated using intraclass correlation coefficient (ICC) and limits of agreement (LOA).

RESULTS

Intraobserver reliability (ICC) using one measurement was 0.50 for one observer and 0.52 for the other, and using the mean of three measurements intraobserver reliability increased up to 0.77 and 0.67, respectively. Interobserver reliability (ICC) when using one measurement was 0.62 and increased to 0.82 when using the average of three measurements. LOA showed that when using the average of three measurements, LOA decreased to 0.6 mm, corresponding to 17.5% of the mean thickness of the PF.

CONCLUSIONS

The results showed that reliability increases when using the mean of three measurements compared with one. Limits of agreement based on intratester reliability shows that changes in thickness that are larger than 0.6 mm can be considered actual changes in thickness and not a result of measurement error.

Sex-related differences in foot shape of adult Caucasians--a follow-up study focusing on long and short feet

The study's purpose was to substantiate findings on sex-related differences in foot morphology focusing on fringe sizes. Altogether, 287 Caucasian adults with long or short feet were scanned. Data were analysed together with data from 847 subjects from a previous study with comparable inclusion criteria and anthropometric data by: (1)comparing absolute measures within 237-277 mm foot length (FL); (2) comparing averaged measures across sizes in % of foot length for 203-323 mm FL; (3) reclassifying the additional subjects into a previously defined foot type classification. Male feet were wider and higher for the same FL. Averaged across sizes, no relevant differences between sexes were found for widths and heights. Slender or flat-pointed foot types were more common in longer feet, shorter feet tended to be bigger. Definitions for 'long' and 'short' are sex-related with an offset of three shoe sizes (EU). Results of this follow-up study on long and short feet can substantiate previous findings mainly described for the most common sizes. STATEMENT OF RELEVANCE: Improper footwear can cause pain and injury and proper fit is a major criterion for shoe buyers. Knowledge about sex-related differences in foot shape is important for shoe design. This study supplements the field of knowledge for very small and large feet.

Didactyl tracks of paravian theropods (Maniraptora) from the ?Middle Jurassic of Africa

Background

A new dinosaur tracksite from ?Middle Jurassic sediments of the Irhazer Group on the plains of Agadez (Rep. Niger, northwest Africa) revealed extraordinarily well preserved didactyl tracks of a digitigrade bipedal trackmaker. The distinct morphology of the pes imprints indicates a theropod trackmaker from a paravian maniraptoran closely related to birds.

Methodology/Principal Findings

The early age and the morphological traits of the tracks allow for description of the new ichnotaxon Paravipus didactyloides. A total of 120 tracks are assigned to 5 individual trackways. The ‘medium-sized’ tracks with an average footprint length of 27.5 cm and footprint width of 23.1 cm are deeply imprinted into the track bearing sandstone.

Conclusions/Significance

A comparison with other didactyl tracks gives new insights into the foot morphology of advanced maniraptoran theropods and contributes to knowledge of their evolutionary history. The new ichnotaxon takes an important position in the ichnological fossil record of Gondwana and the mid-Jurassic biota worldwide, because it is among the earliest known records of paravian maniraptorans and of didactyl theropod tracks from Africa.

['No naturally shaped human foot would end in wedged-in, pointed toes" (Knud Ahlborn)--Wandervögel, youth movement and movement for rational footwear]

The nineteenth century "movement for rational clothing" not only aimed at reforming women's clothes (leaving behind corset-fashion), it set out to improve women's rights in general. Few people know that footwear also was modernized in the second half of the nineteenth century. After shoes had been made for 350 years on the basis of a symmetry pattern, without or with almost invisible distinction between left and right feet, scientists around the Frankfurt born professor of anatomy Georg Hermann von Meyer (1815-1892) demanded with him radical reform of footwear--for both sexes--using new lasts that were modelled on the natural shape of feet. Around the turn of the century, after physicians, shoemakers and hygienists had spent decades debating new ideas, members of the Wandervogel movement adopted the issue for their own purposes and chose anatomic over fashionable yet unhealthy fits which tended to be pointed, slim and--above all--symmetrical. Once the Wandervogel movement had split into several smaller groupings in 1904 and become part of the Jugendbewegung (youth movement), some of its members wanted clothing to also carry symbolic meaning. Naturally-shaped hygienic boots should no longer just allow for walking without damage to the feet: they should become the embodiment of a new spirit and, beyond that, of a reformed society. A new "lay practice" and "do-it-yourself"-shoemaking replaced former academic programs for new natural footwear. Interestingly enough, alongside those quite radical concepts, a kind of "footwear reform light" established itself in the market: on the surface only slightly different from the old-fashioned, symmetrical shoes, these "modern" pairs, which consisted of a right and left shoe, remained successful even after the world wars and became the new standard in the twentieth century, because the shoes made according to this pattern lasted longer, fitted better and were more comfortable.

[Relationship of the flexor hallucis longus and flexor digitorum longus tendons in the plantar midfoot. An anatomical cadaver study]

PURPOSE OF THE STUDY

To verify, in cadaver specimens, the precise anatomic structure of cross-connection between the flexor hallucis longus (FHL) and flexor digitorum longus (FDL) tendons and to identify its position in relation to orientation points in the foot in view of the surgical technique for tendon transfer, including the necessity of subsequent tendon suture.

MATERIAL AND METHODS

A hundred cadaver legs (50 cadavers of 29 men and 21 women, all Caucasians) were dissected by an extensive medio-plantar approach. The anatomical relationship of the FHL and FDL tendons was studied. The distances measured were as follows: between the first metatarsophalangeal joint line and the FHL origin of a tendinous slip; between the slip and the calcaneal tubercle; and the total distance between the first metatarsophalangeal joint line and the calcaneal tubercle.

RESULTS

In all cadaver legs, a cross-connection between the FHL and FDL tendons was present in the plantar midfoot. There was always a tendinous slip branching from the FHL tendon and running lateral and distal to the FDL tendon. The slip was attached to the FDL tendon distal to its branching for the toes; it either attached to only the FDL tendon for the second toe or it split to attach to the FDL tendon branches for the second and the third toe. The two configurations were referred to as type II and type II,III, respectively. Type II was found in both legs of 31 cadavers (62 %), and type II,III in 14 cadavers (28 %). In five cadavers (10 %) attachment was different in the right and the left foot. Expressed in absolute numbers, there were 67 type II attachments (two-thirds of the findings) and 33 type II,III attachments (one-third of the findings). The average distance between the first metatarsophalangeal joint line and the origin of an FHL tendinous slip was 7.3 (± 0.9 ) cm, the average distance between the origin of an FHL tendinous slip and the calcaneal tubercle was 9.2 (± 1.1) cm and the average distance between the first metatarsophalangeal joint line and the calcaneal tubercle was 16.5 (± 1.6) cm.

DISCUSSION

Various presentations of the anatomical relationship between the FHL and FDL tendons in the midfoot are found in the literature. Some describe it as a mere cross-connection between the tendons; others report certain forms of attachment. Only two papers on this issue have recently been available in the international literature and their findings markedly differ from our observations made on a significantly higher number of specimens.

CONCLUSIONS

The FHL and FDL tendons in the midfoot are cross-connected with a tendinous slip branching proximal to the FHL tendon to be attached to the FDL tendon distal to its branching for the second or the third toe. Transfer of the FHL and FDL tendons is often used in the treatment of tibialis posterior muscle dysfunction, extensive inveterated ruptures of the Achilles tendon and, less frequently, posterior foot balancing in neuromuscular foot deformities. The anatomic pattern of a tendon cross-connection in relation to orientation points in the foot varies to such an extent that, during surgery, it is impossible to keep strictly to the recommended halves of the distances between the calcaneal tubercle and the first metatarsophalangeal joint. The length of a FDL graft is limited by the level of tendon branching for the toes; it is not necessary to cut through the slip. Because of the anatomical structure of tendon cross-connection, we consider it necessary to suture the distal stump of one tendon to the other tendon to retain their correct function.

Rearfoot alignment and medial longitudinal arch configurations of runners with symptoms and histories of plantar fasciitis

OBJECTIVE

To evaluate and compare rearfoot alignment and medial longitudinal arch index during static postures in runners, with and without symptoms and histories of plantar fasciitis (PF).

INTRODUCTION

PF is the third most common injury in runners but, so far, its etiology remains unclear. In the literature, rearfoot misalignment and conformations of the longitudinal plantar arch have been described as risk factors for the development of PF. However, in most of the investigated literature, the results are still controversial, mainly regarding athletic individuals and the effects of pain associated with these injuries.

METHODS

Forty-five runners with plantar fasciitis (30 symptomatic and 15 with previous histories of injuries) and 60 controls were evaluated. Pain was assessed by a visual analogue scale. The assessment of rearfoot alignment and the calculations of the arch index were performed by digital photographic images.

RESULTS

There were observed similarities between the three groups regarding the misalignments of the rearfoot valgus. The medial longitudinal arches were more elevated in the group with symptoms and histories of PF, compared to the control runners.

CONCLUSIONS

Runners with symptoms or histories of PF did not differ in rearfoot valgus misalignments, but showed increases in the longitudinal plantar arch during bipedal static stance, regardless of the presence of pain symptoms.

The influence of foot geometry on the calcaneal osteotomy angle based on two-dimensional static force analyses

BACKGROUND

Malalignment of the hindfoot can be corrected with a calcaneal osteotomy (CO). A well-selected osteotomy angle in the sagittal plane will reduce the shear force in the osteotomy plane while walking. The purpose was to determine the presence of a relationship between the foot geometry and loading of the calcaneus, which influences the choice of the preferred CO angle.

METHODS

A static free body force analysis was made of the posterior calcaneal fragment in the second half of the stance phase to determine the main loads: the plantar apeunorosis (PA) and Achilles tendon (AT). The third load is on the osteotomy surface which should be oriented such that the shear component of the force is zero. The force direction of the PA and AT was measured on 58 MRIs of the foot, and the force ratio between both structures was taken from the literature. In addition the PA-to-AT force ratio was estimated for different foot geometries to identify the relationship.

RESULTS

Based on the wish to minimize the shear force during walking, a mean CO angle was determined to be 33° (SD8) relative to the foot sole. In pes planus foot geometry, the angle should be higher than the mean. In pes cavus foot geometry, the angle should be smaller.

CONCLUSION

Foot geometry, in particular the relative foot heights is a determinant for the individual angle in performing the sliding calcaneal osteotomy. It is recommended to take into account the foot geometry (arch) when deciding on the CO angle for hindfoot correction.

Lucy's flat feet: the relationship between the ankle and rearfoot arching in early hominins

BACKGROUND

In the Plio-Pleistocene, the hominin foot evolved from a grasping appendage to a stiff, propulsive lever. Central to this transition was the development of the longitudinal arch, a structure that helps store elastic energy and stiffen the foot during bipedal locomotion. Direct evidence for arch evolution, however, has been somewhat elusive given the failure of soft-tissue to fossilize. Paleoanthropologists have relied on footprints and bony correlates of arch development, though little consensus has emerged as to when the arch evolved.

METHODOLOGY/PRINCIPAL FINDINGS

Here, we present evidence from radiographs of modern humans (n = 261) that the set of the distal tibia in the sagittal plane, henceforth referred to as the tibial arch angle, is related to rearfoot arching. Non-human primates have a posteriorly directed tibial arch angle, while most humans have an anteriorly directed tibial arch angle. Those humans with a posteriorly directed tibial arch angle (8%) have significantly lower talocalcaneal and talar declination angles, both measures of an asymptomatic flatfoot. Application of these results to the hominin fossil record reveals that a well developed rearfoot arch had evolved in Australopithecus afarensis. However, as in humans today, Australopithecus populations exhibited individual variation in foot morphology and arch development, and "Lucy" (A.L. 288-1), a 3.18 Myr-old female Australopithecus, likely possessed asymptomatic flat feet. Additional distal tibiae from the Plio-Pleistocene show variation in tibial arch angles, including two early Homo tibiae that also have slightly posteriorly directed tibial arch angles.

CONCLUSIONS/SIGNIFICANCE

This study finds that the rearfoot arch was present in the genus Australopithecus. However, the female Australopithecus afarensis "Lucy" has an ankle morphology consistent with non-pathological flat-footedness. This study suggests that, as in humans today, there was variation in arch development in Plio-Pleistocene hominins.

A study of correlation of hand and foot dimensions for personal identification in mass disasters

The identification of isolated extremities is an issue of great significance in the investigation of the identity of victims of mass disasters and fatal assaults. In forensic investigations, the dimensions of the hand and foot have been used for determination of sex, age and stature of an individual. However, the data on correlation within and between hand and foot dimensions are very limited. The present research aims at analysing the anthropometrical relationships within and between hand and foot dimensions. The study was conducted on 240 Rajputs (120 males and 120 females) from North India. The results showed a significant correlation between and within the dimensions of hands and feet. Multiplication factors, linear and multiple regression models are derived to reconstruct the hand and foot even when a single dimension is available from the extremities. Besides medico-legal implications, the study may have significance in plastic and reconstructive surgery.

Laetoli footprints preserve earliest direct evidence of human-like bipedal biomechanics

Background

Debates over the evolution of hominin bipedalism, a defining human characteristic, revolve around whether early bipeds walked more like humans, with energetically efficient extended hind limbs, or more like apes with flexed hind limbs. The 3.6 million year old hominin footprints at Laetoli, Tanzania represent the earliest direct evidence of hominin bipedalism. Determining the kinematics of Laetoli hominins will allow us to understand whether selection acted to decrease energy costs of bipedalism by 3.6 Ma.

Methodology/Principal Findings

Using an experimental design, we show that the Laetoli hominins walked with weight transfer most similar to the economical extended limb bipedalism of humans. Humans walked through a sand trackway using both extended limb bipedalism, and more flexed limb bipedalism. Footprint morphology from extended limb trials matches weight distribution patterns found in the Laetoli footprints.

Conclusions

These results provide us with the earliest direct evidence of kinematically human-like bipedalism currently known, and show that extended limb bipedalism evolved long before the appearance of the genus Homo. Since extended-limb bipedalism is more energetically economical than ape-like bipedalism, energy expenditure was likely an important selection pressure on hominin bipeds by 3.6 Ma.

Euarchontan affinity of Paleocene Afro-European adapisoriculid mammals and their origin in the late Cretaceous Deccan Traps of India

The controversial family Adapisoriculidae, a group of shrew-sized Paleocene mammals, had proposed relationships with insectivores, marsupials and more recently to plesiadapiforms. Adapisoriculid remains are numerous in the early Paleocene locality of Hainin, Belgium, and allow us a test of these different phylogenetic hypotheses. Here, we identify the first tarsal bones of adapisoriculid mammals. The highly specialised bones indicate an arboreal mode of life with euarchontan affinity. Moreover, the tarsal bones are morphologically very close to those of the late Cretaceous Deccanolestes from the Deccan intertrappean beds of India, and also share several characters with the Paleocene plesiadapiforms and the extant cynocephalid dermopterans. The adapisoriculid affinities of Deccanolestes are also confirmed by tooth morphology, indicating that Deccanolestes is a primitive member of this family. These phylogenetic affinities suggest a paleobiogeographic scenario for the family with dispersal either via East Africa or across the Tethys area.

[Measurements using projection moiré of the length and width of feet in standing females and males aged 4 to 18 years]

INTRODUCTION

The foot changes with age from wide and short in neonates to intermediate in teenagers.

OBJECTIVE

To describe changes in mean length and width of the foot during fast and slow phases of growth between the age of 4 and 18 years in the female and male population.

MATERIAL AND METHODS

The study was done in 9804 girls and 8699 boys aged 4 to 18 years, randomly selected from kindergartens and schools of the Warmia and Mazury region. The computerized body posture station and the projection moiré technique were used. The results are presented graphically.

CONCLUSIONS

1. The rate of increase in the length and width of the foot in the female and male population is steady between the age of 4 and 18 years but shows a trough at the age of 14 years. 2. The mean foot length and width values were significantly greater in 2003 than in 1990.

UV-assisted capillary force lithography for engineering biomimetic multiscale hierarchical structures: From lotus leaf to gecko foot hairs

This feature article provides an overview of the recently developed two-step UV-assisted capillary force lithography and its application to fabricating well-defined micro/nanoscale hierarchical structures. This method utilizes an oxygen inhibition effect in the course of UV irradiation curing and a two-step moulding process, to form multiscale hierarchical or suspended nanobridge structures in a rapid and reproducible manner. After a brief description of the fabrication principles, several examples of the two-step UV-assisted moulding technique are presented. In addition, emerging applications of the multiscale hierarchical structures are briefly described.

Kd-Jump: a path-preserving stackless traversal for faster isosurface raytracing on GPUs

Stackless traversal techniques are often used to circumvent memory bottlenecks by avoiding a stack and replacing return traversal with extra computation. This paper addresses whether the stackless traversal approaches are useful on newer hardware and technology (such as CUDA). To this end, we present a novel stackless approach for implicit kd-trees, which exploits the benefits of index-based node traversal, without incurring extra node visitation. This approach, which we term Kd-Jump, enables the traversal to immediately return to the next valid node, like a stack, without incurring extra node visitation (kd-restart). Also, Kd-Jump does not require global memory (stack) at all and only requires a small matrix in fast constant-memory. We report that Kd-Jump outperforms a stack by 10 to 20% and kd-restart by 100%. We also present a Hybrid Kd-Jump, which utilizes a volume stepper for leaf testing and a run-time depth threshold to define where kd-tree traversal stops and volume-stepping occurs. By using both methods, we gain the benefits of empty space removal, fast texture-caching and realtime ability to determine the best threshold for current isosurface and view direction.

Automatic transfer function generation using contour tree controlled residue flow model and color harmonics

Transfer functions facilitate the volumetric data visualization by assigning optical properties to various data features and scalar values. Automation of transfer function specifications still remains a challenge in volume rendering. This paper presents an approach for automating transfer function generations by utilizing topological attributes derived from the contour tree of a volume. The contour tree acts as a visual index to volume segments, and captures associated topological attributes involved in volumetric data. A residue flow model based on Darcy's Law is employed to control distributions of opacity between branches of the contour tree. Topological attributes are also used to control color selection in a perceptual color space and create harmonic color transfer functions. The generated transfer functions can depict inclusion relationship between structures and maximize opacity and color differences between them. The proposed approach allows efficient automation of transfer function generations, and exploration on the data to be carried out based on controlling of opacity residue flow rate instead of complex low-level transfer function parameter adjustments. Experiments on various data sets demonstrate the practical use of our approach in transfer function generations.

Combining prehension and propulsion: the foot of Ardipithecus ramidus

Several elements of the Ardipithecus ramidus foot are preserved, primarily in the ARA-VP-6/500 partial skeleton. The foot has a widely abducent hallux, which was not propulsive during terrestrial bipedality. However, it lacks the highly derived tarsometatarsal laxity and inversion in extant African apes that provide maximum conformity to substrates during vertical climbing. Instead, it exhibits primitive characters that maintain plantar rigidity from foot-flat through toe-off, reminiscent of some Miocene apes and Old World monkeys. Moreover, the action of the fibularis longus muscle was more like its homolog in Old World monkeys than in African apes. Phalangeal lengths were most similar to those of Gorilla. The Ardipithecus gait pattern would thus have been unique among known primates. The last common ancestor of hominids and chimpanzees was therefore a careful climber that retained adaptations to above-branch plantigrady.

A new approach to children's footwear based on foot type classification

Current shoe designs do not allow for the comprehensive 3-D foot shape, which means they are unable to reproduce the wide variability in foot morphology. Therefore, the purpose of this study was to capture these variations of children's feet by classifying them into groups (types) and thereby provide a basis for their implementation in the design of children's shoes. The feet of 2867 German children were measured using a 3-D foot scanner. Cluster analysis was then applied to classify the feet into three different foot types. The characteristics of these foot types differ regarding their volume and forefoot shape both within and between shoe sizes. This new approach is in clear contrast to previous systems, since it captures the variability of foot morphology in a more comprehensive way by using a foot typing system and therefore paves the way for the unimpaired development of children's feet. Previous shoe systems do not allow for the wide variations in foot morphology. A new approach was developed regarding different morphological foot types based on 3-D measurements relevant in shoe construction. This can be directly applied to create specific designs for children's shoes.

Foot surface area database and estimation formula

The purpose of this study is to establish a foot surface area (FSA) database and estimation formula based on 3-D foot scan data. For each gender, 135 subjects stratified in five statures and three body weights were drawn. The foot was measured using a high-resolution 3-D foot scanner, of which the precision and accuracy is within 1%. The FSA was computed by the triangular mesh summation method and five 1-D foot measurements were extracted automatically to be used as candidate estimators for FSA estimation formula. The results of the FSA measurements are tabulated on fifteen strata for the Male, the Female and the Total (the two genders combined). The comparison of these FSA measurements with previous studies shows that previous studies underestimated the FSA approximately 4.06% for the Total (for the Male, 6.93%; for the Female, 0.82%). Regression analyses using these five 1-D foot measurements were performed. The results show that foot-length and ball-girth are effective estimators of FSA for the total (FSA=1.043 x foot-length x ball-girth, R(2)=95.4%). A test on the necessity of gender-specific formula indicated that no gender-specific formula is needed, and the formula for the total is good for both genders.

Surgical anatomy for a new minimally invasive approach to harvest the flexor digitorum longus tendon: a cadaver study

AIM

The purpose of this cadaver study was to test feasibility and safety of a new technique for harvesting the FDL tendon through a plantar incision placed directly overlying the FDL division and to define the relevant surgical anatomy.

METHODS

In eight cadaver feet the FDL tendon was exposed in the midfoot through a plantar incision. In four of these feet this was done after localization of the FDL division site using a probe inserted through a wound in the hindfoot within the sheath of FDL tendon. The exact location was measured in relation to the geometry of the foot and was found to be midway between the back of the heel and the base of the second toe and about 4 cm medial to the lateral border of the foot. Using these determinants FDL was exposed on the contralateral matching four feet without use of the probe. The FDL tendon was divided and pulled proximally and the length of the tendon was determined.

RESULTS

The FDL division lies midway between the back of the heel and the base of the second toe and about 3.7 cm medial to the lateral border of the foot. The medial and the lateral plantar neurovascular bundles are, respectively, about 0.43 cm and 0.86 cm away from the FDL division. The average length of the retrieved tendon was about 9 cm.

CONCLUSIONS

This cadaver study suggests that the FDL tendon can be safely harvested through a plantar incision. The adjacent neurovascular structures remained undamaged. Plantar surface anatomy guides placement of the plantar incision so that the incision can overlie directly over the FDL division.

Oriented active shape models

Active shape models (ASM) are widely employed for recognizing anatomic structures and for delineating them in medical images. In this paper, a novel strategy called oriented active shape models (OASM) is presented in an attempt to overcome the following five limitations of ASM: 1) lower delineation accuracy, 2) the requirement of a large number of landmarks, 3) sensitivity to search range, 4) sensitivity to initialization, and 5) inability to fully exploit the specific information present in the given image to be segmented. OASM effectively combines the rich statistical shape information embodied in ASM with the boundary orientedness property and the globally optimal delineation capability of the live wire methodology of boundary segmentation. The latter characteristics allow live wire to effectively separate an object boundary from other nonobject boundaries with similar properties especially when they come very close in the image domain. The approach leads to a two-level dynamic programming method, wherein the first level corresponds to boundary recognition and the second level corresponds to boundary delineation, and to an effective automatic initialization method. The method outputs a globally optimal boundary that agrees with the shape model if the recognition step is successful in bringing the model close to the boundary in the image. Extensive evaluation experiments have been conducted by utilizing 40 image (magnetic resonance and computed tomography) data sets in each of five different application areas for segmenting breast, liver, bones of the foot, and cervical vertebrae of the spine. Comparisons are made between OASM and ASM based on precision, accuracy, and efficiency of segmentation. Accuracy is assessed using both region-based false positive and false negative measures and boundary-based distance measures. The results indicate the following: 1) The accuracy of segmentation via OASM is considerably better than that of ASM; 2) The number of landmarks can be reduced by a factor of 3 in OASM over that in ASM; 3) OASM becomes largely independent of search range and initialization becomes automatic. All three benefits of OASM ensue mainly from the severe constraints brought in by the boundary-orientedness property of live wire and the globally optimal solution found by the 2-level dynamic programming algorithm.

Effects of surface characteristics on the plantar shape of feet and subjects' perceived sensations

Orthotics and other types of shoe inserts are primarily designed to reduce injury and improve comfort. The interaction between the plantar surface of the foot and the load-bearing surface contributes to foot and surface deformations and hence to perceived comfort, discomfort or pain. The plantar shapes of 16 participants' feet were captured when standing on three support surfaces that had different cushioning properties in the mid-foot region. Foot shape deformations were quantified using 3D laser scans. A questionnaire was used to evaluate the participant's perceptions of perceived shape and perceived feeling. The results showed that the structure in the mid-foot could change shape, independent of the rear-foot and forefoot regions. Participants were capable of identifying the shape changes with distinct preferences towards certain shapes. The cushioning properties of the mid-foot materials also have a direct influence on perceived feelings. This research has strong implications for the design and material selection of orthotics, insoles and footwear.

[Diagnosis of human lifetime height using foot length in forensic medical examination of corpse fragments]

This review of domestic and foreign literature concerns methods for the rough estimation of human height based on the results of foot measurement. The efficiency of all these methods appears to be very low since they yield differing and mostly unreliable information. Their main drawback is attributable to the poor dependence between the foot length and the height. This situation necessitated a new study in the search for more accurate estimates of the anatomic relationship between the two variables. The comprehensive anthropometric examination included a total of 3457 subjects (2073 men and 1384 women). It was shown that the two genders differ in terms of the height-to-foot length ratio; moreover, the mean value of this ratio varies depending on the foot length of individual subjects in the range from 6.2 to 7.1 (for women) and from 6.54 to 7.49 (for men). The length of the foot is negatively correlated with the coefficient describing its relationship to the height; the coefficient decreases with increasing foot length. Also, it may differ at a constant length of the foot within 0.6 and 0.62 in men and women respectively.

[Structural and functional changes of the foot after cyclic centrifugal physical loads in sports runners]

Foot structural and functional peculiarities after cyclic centrifugal physical loads in sports runners were studied. The work demonstrates the results of computer morphometry of 120 athlete runners (50 boys and 70 girls) aged 15-17 years--the students of Volgograd School of Olympic Reserve and Volgograd State Academy of Physical Education. Cyclic centrifugal loads of shock-type (long run on an inclined plane) resulted in significant reduction of the foot arch hight. In female runners, the reduction was found mainly in the longitudinal foot arch, while in male runners it was detected in transverse foot arch. Two basic types of foot arch reaction to prolonged cyclic loads were detected. This allowed us, for the first time, to divide the static flat-footedness into two major categpries: compensated, or dynamic, and true. In compensated static flat-footedness, the structural and functional foot parameters returned to their initial levels after the rehabilitation, while in true flat-footedness the complex rehabilitation measures could not restore the initial morpho-functional parameters: foot arches remained reduced.

[Functional stability of the vertical posture in children depending on foot arch condition]

Functional stability of the vertical posture was evaluated in 112 children aged 7-10 years with normal or flattened arch of foot and platypodia. The following parameters were measured in each child during 20 s by a Stabilan 01 computerized stabilograph: stabilogram, average frequency of centre of pressure changes, mean dispersion (R), oscillation period, and ellipse area (S). Children with flattened foot arch had lower vertical posture stability (estimated from amplitude characteristics of changes of the foot pressure centre, R and S) than those with normal foot arch or platypodia. Children of the latter group showed the highest stability and the minimal oscillation period. It is supposed that difference in functional stability of the vertical posture in children with different foot arch conditions is due to different mechanisms of its regulation. The above findings can be used to design orthopedic footwear compensating for impaired stability of the vertical posture in children with flattened arch of the foot.

Elements of morphology: standard terminology for the hands and feet

An international group of clinicians working in the field of dysmorphology has initiated the standardization of terms used to describe human morphology. The goals are to standardize these terms and reach consensus regarding their definitions. In this way, we will increase the utility of descriptions of the human phenotype and facilitate reliable comparisons of findings among patients. Discussions with other workers in dysmorphology and related fields, such as developmental biology and molecular genetics, will become more precise. Here we introduce the anatomy of the hands and feet and define and illustrate the terms that describe the major characteristics of the hands and feet.

A simple, anatomically based correction to the conventional ankle joint center

BACKGROUND

Conventional motion analysis studies define the ankle joint center as the midpoint between the most medial and lateral aspects of the malleoli, yet research points toward a more distal joint center location. The purpose of this study was to develop and evaluate an anatomically based correction that would move the conventional ankle joint center to a more accurate location.

METHODS

Lower extremity radiographs from 30 pediatric patients were analyzed retrospectively. An offset between the conventional and more accurate ankle joint centers was measured and correlated to other common anatomical measures based on conventional skin mounted marker positions. The best correlated measure was used to define a simple correction factor, which was subsequently evaluated by its effect on six degree-of-freedom ankle joint translations during normal gait (n=8).

FINDINGS

Shank length was found to have the highest bivariate linear correlation (r=0.89) with the offset. Adjusting the ankle joint center using a percentage of shank length (2.7%) was also as accurate as the regression equation in predicting offset (mean error 0.6mm, or 6% offset). Adjusting the ankle joint center using this simple percentage resulted in a 25% reduction in mean ankle joint translations during normal gait.

INTERPRETATION

The accuracy of the ankle joint center can be increased through a simple, anatomically based correction. This correction may prove beneficial in some kinematic and kinetic applications requiring increased anatomical fidelity.

The validity and reliability of a simple semantic classification of foot posture

INTRODUCTION

The Simple Semantic Classification (SSC) is described as a pragmatic method to assist in the assessment of the weight bearing foot. It was designed for application by therapists and technicians working in underdeveloped situations, after they have had basic orientation in foot function.

OBJECTIVE

To present evidence of the validity and inter observer reliability of the SSC.

METHOD

13 physiotherapists from LEPRA India projects and 12 physical therapists functioning within the National Programme for the Elimination of Hansen's Disease (PNEH), Brazil, participated in an inter-observer exercise. Inter-observer agreement was gauged using the Kappa statistic. The results of the inter-observer exercise were dependent on observations of foot posture made from photographs. This was necessary to ensure that the procedure was standardised for participants in different countries. The method had limitations which were partly reflected in the results.

RESULTS

The level of agreement between the principle investigator and Indian physiotherapists was Kappa = 058. The level of agreement between Brazilian physical therapists and the principle investigator was Kappa = 0.70.

CONCLUSION

The authors opine that the results were sufficiently compelling to suggest that the Simple Semantic Classification can be used as a field method to identify people at increased risk of foot pathologies.

Phylogenetic variation in flexor digitorum brevis: a Nepalese cadaveric study

Understanding muscle architecture of the foot may assist in the design of surgical procedures such as tendon transfer, biomechanical modeling of the foot, prosthesis design, and analysis of foot function. Flexor digitorum brevis (FDB) is the most superficial intrinsic muscle of the sole of the foot. When compared to the little finger, the little toe has less function and opposition is absent in humans. Hence, the muscles acting on the little toe are undergoing evolutionary changes. The objective of this study was to review the phylogenetic variation occurring in FDB in the Nepalese cadavers. Sixty soles in 20 male and 10 female adult embalmed cadavers were dissected and attachments of FDB observed. It was noted that the tendon for the fifth toe was missing in all sixty soles. The action of FDB can be compensated by other long flexors of the foot. This could have resulted due to gradual reduction in the usage of the little toe as the bipedal posture evolved. Variations of FDB are clinically important because FDB musculocutanous flap is used in the reconstruction of the heel pad.

Foot ulcer risk and location in relation to prospective clinical assessment of foot shape and mobility among persons with diabetes

AIMS

We assessed baseline clinical foot shape for 2939 feet of diabetic subjects who were monitored prospectively for foot ulceration.

METHODS

Assessments included hammer/claw toes, hallux valgus, hallux limitus, prominent metatarsal heads, bony prominences, Charcot deformity, plantar callus, foot type, muscle atrophy, ankle and hallux mobility, and neuropathy. Risk factors were linked to ulcer occurrence and location via a Cox proportional hazards model.

RESULTS

Hammer/claw toes (hazard ratio [HR] (95% confidence interval [CI])=1.43 (1.06, 1.94) p=0.02), marked hammer/claw toes (HR=1.77 (1.18, 2.66) p=0.006), bony prominences (HR=1.38 (1.02, 1.88), p=0.04), and foot type (Charcot or drop foot vs. neutrally aligned) (HR=2.34 (1.33, 4.10), p=0.003) were significant risk factors for ulceration adjusting for age, body mass index, insulin medication, ulcer history and amputation history. With adjustment for neuropathy only hammer/claw toes (HR=1.40 (1.03, 1.90), p=0.03) and foot type (HR=1.76 (1.04, 3.04), p=0.05) were significantly related to ulceration. However, there was no relationship between ulcer location and foot deformity.

CONCLUSIONS

Certain foot deformities were predictive of ulceration, although there was no relationship between clinical foot deformity and ulcer location.

Sex-related differences in foot shape

The purpose of the study was to investigate sex-related differences in foot morphology. In total, 847 subjects were scanned using a 3-D-footscanner. Three different analysis methods were used: (1) comparisons were made for absolute foot measures within 250-270 mm foot length (FL); (2) and for averaged measures (% FL) across all sizes; (3) the feet were then classified using a cluster analysis. Within 250-270 mm FL, male feet were wider and higher (mean differences (MD) 1.3-5.9 mm). No relevant sex-related differences could be found in the comparison of averaged measures (MD 0.3-0.6% FL). Foot types were categorised into voluminous, flat-pointed and slender. Shorter feet were more often voluminous, longer feet were more likely to be narrow and flat. However, the definition of 'short' and 'long' was sex-related; thus, allometry of foot measures was different. For shoe design, measures should be derived for each size and sex separately. Different foot types should be considered to account for the variety in foot shape. Improper footwear can cause foot pain and deformity. Therefore, knowledge of sex-related differences in foot measures is important to assist proper shoe fit in both men and women. The present study supplements the field of knowledge within this context with recommendations for the manufacturing of shoes.