Development of the infant foot as a load bearing structure: study protocol for a longitudinal evaluation (the Small Steps study)

BACKGROUND

An improved understanding of the structural and functional development of the paediatric foot is fundamental to a strong theoretical framework for health professionals and scientists. An infant's transition from sitting, through crawling and cruising, to walking is when the structures and function of the foot must adapt to bearing load. The adaptation of skin and other hard and soft tissue, and foot and gait biomechanics, during this time is poorly understood. This is because data characterising the foot tissue and loading pre-walking onset does not exist. Of the existing kinematic and plantar pressure data, few studies have collected data which reflects the real-life activities of infants with modern equipment.

METHODS

This is a longitudinal study and part of the Great Foundations Initiative, a collaborative project between the University of Brighton and the University of Salford, which is seeking to improve foot health in children. Two cohorts of 50 infants will be recruited at the two sites (University of Brighton, Eastbourne, UK and University of Salford, Salford, UK). Infants will be recruited when they first reach for their feet and attend four laboratory visits at milestones related to foot loading, with experienced independent walking being the final milestone. Data collection will include tissue characteristics (skin thickness, texture, elasticity, pH and tendon thickness and cross-sectional area), plantar pressures and kinematics captured during real world locomotion tasks.

DISCUSSION

This study will provide a database characterising the development of the infant foot as it becomes a weight bearing structure. The data will allow effective comparison and quantification of changes in structure and function due to maturation and loading by measuring pre and post established walking. Additional variables which impact on the development of the foot (gender, ethnicity and body weight) will also be factored into our analysis. This will help us to advance understanding of the determinants of foot development in early childhood.

Multivariate analysis of variations in intrinsic foot musculature among hominoids

Comparative analysis of the foot muscle architecture among extant great apes is important for understanding the evolution of the human foot and, hence, human habitual bipedal walking. However, to our knowledge, there is no previous report of a quantitative comparison of hominoid intrinsic foot muscle dimensions. In the present study, we quantitatively compared muscle dimensions of the hominoid foot by means of multivariate analysis. The foot muscle mass and physiological cross-sectional area (PCSA) of five chimpanzees, one bonobo, two gorillas, and six orangutans were obtained by our own dissections, and those of humans were taken from published accounts. The muscle mass and PCSA were respectively divided by the total mass and total PCSA of the intrinsic muscles of the entire foot for normalization. Variations in muscle architecture among human and extant great apes were quantified based on principal component analysis. Our results demonstrated that the muscle architecture of the orangutan was the most distinctive, having a larger first dorsal interosseous muscle and smaller abductor hallucis brevis muscle. On the other hand, the gorilla was found to be unique in having a larger abductor digiti minimi muscle. Humans were distinguished from extant great apes by a larger quadratus plantae muscle. The chimpanzee and the bonobo appeared to have very similar muscle architecture, with an intermediate position between the human and the orangutan. These differences (or similarities) in architecture of the intrinsic foot muscles among humans and great apes correspond well to the differences in phylogeny, positional behavior, and locomotion.

The three-dimensional shapes of underground coal miners' feet do not match the internal dimensions of their work boots

Mining work boots provide an interface between the foot and the ground, protecting and supporting miners' feet during lengthy coal mining shifts. Although underground coal miners report the fit of their work boots as reasonable to good, they frequently rate their boots as uncomfortable, suggesting that there is a mismatch between the shape of their feet and their boots. This study aimed to identify whether dimensions derived from the three-dimensional scans of 208 underground coal miners' feet (age 38.3 ± 9.8 years) differed from the internal dimensions of their work boots. The results revealed underground coal miners wore boots that were substantially longer than their feet, possibly because boots available in their correct length were too narrow. It is recommended boot manufacturers reassess the algorithms used to create boot lasts, focusing on adjusting boot circumference at the instep and heel relative to increases in foot length. Practitioner Summary: Fit and comfort ratings suggest a mismatch between the shape of underground coal miners' feet and their boots exists. This study examined whether three-dimensional scans of 208 miners' feet differed from their boot internal dimensions. Miners wore boots substantially longer than their feet, possibly due to inadequate width.

Appropriate Area for Operative Procedures Near Tibialis Anterior Tendon Insertion: A Cadaveric Study

BACKGROUND

The tibialis anterior tendon has its insertion sites on both the medial and plantar surfaces of the medial cuneiform and the base of the first metatarsal. Operative procedures near those areas, especially at the first metatarsocuneiform joint, may disturb tendon insertions and cause irritation or functional impairment of the tendon.

METHODS

Tibialis anterior tendons and their insertion sites were dissected and examined from 46 cadaveric feet (19 female and 27 male cadavers, aged between 33 and 86 years, with a mean of 68.5 ± 14.3 years). The greatest lengths and widths of the tendon attachments on the bony surface of the medial cuneiform and base of the first metatarsal, on both the medial and plantar surfaces, were measured and analyzed. The measurement reliability was evaluated by using the intraclass correlation coefficient.

RESULTS

Most of the tibialis anterior tendon insertions were found to be longer at the medial cuneiform than at the base of the first metatarsal (mean, 8.3 and 5.4 mm; P < .001), but the widths were almost similar (mean, 11.0 and 10.4 mm; P = .079). When focusing on each bone, the widths of the tendon attachments on the medial and plantar surfaces of the medial cuneiform were equivalent (mean, 5.4 and 5.6 mm; P = .584). At the base of the first metatarsal, the tendon attachment on the plantar surface was found to be wider than on the medial surface (mean, 7.0 and 3.4 mm; P < .001).

CONCLUSION

The widths of the tibialis anterior tendon insertions on the medial and plantar surfaces of the medial cuneiform were equal, as were the total widths of insertions on the medial cuneiform and on the base of the first metatarsal. However, the width of insertions on the medial surface of the first metatarsal was significantly smaller than on the plantar surface, and the total length of insertions at the medial cuneiform was longer than at the first metatarsal.

CLINICAL RELEVANCE

This study provides information about characteristics of the tibialis anterior tendon insertions, particularly details of the dimensions on each surface of the bones. This knowledge enables surgeons to minimize the risk of irritation or tendon injuries during operations near the base of the first metatarsal and medial cuneiform area.

A new RF transmit coil for foot and ankle imaging at 7T MRI

A four-channel Tic-Tac-Toe (TTT) transmit RF coil was designed and constructed for foot and ankle imaging at 7T MRI. Numerical simulations using an in-house developed FDTD package and experimental analyses using a homogenous phantom show an excellent agreement in terms of B1+ field distribution and s-parameters. Simulations performed on an anatomically detailed human lower leg model demonstrated an B1+ field distribution with a coefficient of variation (CV) of 23.9%/15.6%/28.8% and average B1+ of 0.33μT/0.56μT/0.43μT for 1W input power (i.e., 0.25W per channel) in the ankle/calcaneus/mid foot respectively. In-vivo B1+ mapping shows an average B1+ of 0.29μT over the entire foot/ankle. This newly developed RF coil also presents acceptable levels of average SAR (0.07W/kg for 10g per 1W of input power) and peak SAR (0.34W/kg for 10g per 1W of input power) over the whole lower leg. Preliminary in-vivo images in the foot/ankle were acquired using the T2-DESS MRI sequence without the use of a dedicated receive-only array.

How foot morphology changes influence shoe comfort and plantar pressure before and after long distance running?

PURPOSE

Prolonged running has been popularized globally in recent decades. This study was aimed to reveal information about foot morphology, shoe comfort and plantar loading among recreational heel-strike runners.

METHODS

Twenty-six runners participated in foot morphology, perceived scores and peak pressure tests after 10- and 20-km track running. The foot morphology was measured using a 3D foot scanner, perceived scores were recorded using a visual analogue scale and plantar pressure was measured via insole plantar pressure measurement system. The statistical significance level was set at 0.05.

RESULTS

The heel midsole materials properties were measured before and after 20 km. Significant changes were observed in ball width and girth, arch height and foot volume. The perceived scores showed significance in overall, forefoot and heel comfort, arch support and forefoot width. Peak pressure to the heel, medial mid-foot and metatarsal greatly increased. The first metatarsal showed consecutive increase from static to 10 km, and 20 km, while big-toe showed a decrease.

CONCLUSIONS

The morphology variations and forefoot loading concentration may lead to discomfort and possibly imply dermatological problems and metatarsal bone stress, particularly on the first metatarsal. Combining changes of heel midsole property, knowledge of foot shape, shoe perception and plantar pressure is of great value for recreational long-distance running shoes design and materials selection.

The potential of ultrasonography in the evaluation of foot orthotics therapy

Foot orthotics prescription is based on the foot functioning paradigms with tissue stress theory being in avant-garde. The main goal of orthotic therapy is to reduce the internal tissue's pathological stresses in the foot structures. Traditionally, ultrasound scanning technique depicts anatomic related data of both common and uncommon pathology encountered in the clinical practice, helping in diagnosing, treating and evaluating, which are equally important for the practitioners. Its accessibility, compared to biomechanical modelling, makes this technique a valuable tool in the field of foot and ankle disorders. Despite its user-dependent limitation, the ongoing technical progress improves the ability of ultrasonography as a highly advanced procedure in musculoskeletal imaging, being also a valuable searching tool for musculotendinous mechanics or morphological changes as a result of a conservative intervention. The aim of the present work was to perform a review of the state of the art concerning the usefulness of ultrasonography in the study of foot orthotic therapy and to analyze its effectiveness.

Medial Longitudinal Arch Angle Presents Significant Differences Between Foot Types: A Biplane Fluoroscopy Study

The structure of the medial longitudinal arch (MLA) affects the foot's overall function and its ability to dissipate plantar pressure forces. Previous research on the MLA includes measuring the calcaneal-first metatarsal angle using a static sagittal plane radiograph, a dynamic height-to-length ratio using marker clusters with a multisegment foot model, and a contained angle using single point markers with a multisegment foot model. The objective of this study was to use biplane fluoroscopy to measure a contained MLA angle between foot types: pes planus (low arch), pes cavus (high arch), and normal arch. Fifteen participants completed the study, five from each foot type. Markerless fluoroscopic radiostereometric analysis (fRSA) was used with a three-dimensional model of the foot bones and manually matching those bones to a pair of two-dimensional radiographic images during midstance of gait. Statistically significant differences were found between barefoot arch angles of the normal and pes cavus foot types (p = 0.036), as well as between the pes cavus and pes planus foot types (p = 0.004). Dynamic walking also resulted in a statistically significant finding compared to the static standing trials (p = 0.014). These results support the classification of individuals following a physical assessment by a foot specialist for those with pes cavus and planus foot types. The differences between static and dynamic kinematic measurements were also supported using this novel method.

Histological and functional characterizations of the digital cushion in Quarter horses

The digital cushion (DC) plays a role in absorbing and dampening forces applied to the foot and therefore supports internal structures such as navicular bone; yet, its architecture is not well-known. The goal of this study was to characterize the microanatomical structure of the DC in horses with clinically sound hooves. Both forefeet from the cadavers of 12 adult Quarter horses were cut and sectioned and samples of the following 4 regions of the DC were obtained: axial proximal (AxProx), axial distal (AxDis), abaxial lateral (AbxLat), and abaxial medial (AbxMed). The samples were processed and stained with hematoxylin and eosin, Masson's trichrome, and Weigert's elastic stains. On each slide, 2 central 3- × 3-mm areas were microscopically assessed and all measurements were done within the 9-mm² area. The number of detected collagen bundles, nerve fascicles, vessels, and the diameter of wall thickness and lumen of blood vessels were measured. Elastic fiber profiles were categorized based on relative density of elastic fibers detected in the field. The percentage of samples in which chondrocytes and adipose tissues were either present or absent was calculated. Significant structural differences were identified among the 4 regions of the DC. The AxDis region contained more collagen bundles (P < 0.0001) and less elastic fiber profiles than the AxProx region (P < 0.0001). The AxDis also contained more collagen bundles than the AbxMed and AbxLat (P < 0.0001) regions. Our findings provide insight into the structure of the DC of mature Quarter horses. The structural differences in the various regions of the DC are presumably related to the different functional properties of those regions; yet more research is warranted.

The typically developing paediatric foot: how flat should it be? A systematic review

BACKGROUND

All typically developing children are born with flexible flat feet, progressively developing a medial longitudinal arch during the first decade of their lives. Whilst the child's foot is expected to be flat, there is currently no consensus as to how flat this foot should be. Furthermore, whilst feet are observed to decrease in flatness with increasing age, it is not known how flat they should be at each age increment. The objective of this systematic review is to define the postural characteristics of the 'typically' developing paediatric foot.

METHODS

The PRISMA protocol was applied to compare all data currently published describing the typical development of the paediatric foot. The Epidemiological Appraisal Instrument (EAI) was used to assess the risk of bias of the included studies.

RESULTS

Thirty four epidemiological papers pertaining to the development of the paediatric foot were graphically compared. Sixteen different foot posture assessments were identified of which footprint based measures were the most reported outcome.

CONCLUSION

Firstly, the use of the term normal in relation to foot posture is misleading in the categorisation of the paediatric foot, as indeed a flat foot posture is a normal finding at specific ages. Secondly, the foot posture of the developing child is indeed age dependent and has been shown to change over time. Thirdly, no firm conclusion could be reached as to which age the foot posture of children ceases to develop further, as no two foot measures are comparable, therefore future research needs to consider the development of consensus recommendations as to the measurement of the paediatric foot, using valid and reliable assessment tools.

Correlation of Stature with Foot Length in 5-10 Years Aged Bangladeshi Children

This cross sectional, descriptive and analytic type study was conducted among 5-10 years aged Bangladeshi children at different areas of Mymensingh district (Fulpur, Muktagacha, Fulbaria, Trisal and Haluaghat) on 109 Bangladeshi children (70 male and 39 female) from January 2016 to December 2016. Sample collection was done by nonrandom purposive sampling technique. Any kind of foot deformity resulting either from congenital or physical injury were excluded to construct standard measurement. The present anthropometric study was designed to construct data of 5 to 10 years aged Bangladeshi children regarding foot length, to measure correlation of stature with foot length and an attempt has been made out to grow interest among the researchers for future study and also to compare the data with the data of the people of other races. Stature of the subject was measured with the stadiometer and foot length was measured using slide calipers. The children were asked to stand with weight distributed equally on both feet. The legs were perpendicular to the feet. The mean foot length of 5, 6, 7, 8, 9 and 10 years aged male were 16.72±1.11cm, 17.12±.72cm, 19.04±1.27cm, 19.10±.76cm, 20.11±1.25cm and 20.88±1.01cm respectively and those of same aged female were 16.44±1.2cm, 17.85±0.50cm, 18.53±0.76cm, 19.14±0.58cm, 19.87±1.88cm and 20.95±1.36cm respectively. Correlation between stature and foot length was made. Foot length showed non- significant positive correlation with stature in 5 years old male and female, 6 years old male, 7 years old male and female, 8 years old male and female, 9 years old and 10 years old female. In case of 9 years and 10 years old male, it showed significant positive correlation with stature. Comparison of foot length between male and female children was done by Unpaired Students 't' test which was statistically non-significant.

Foot shape in arboreal birds: two morphological patterns for the same pincer-like tool

The feet are the only contact between the body and the substrate in limbed animals and as such they provide a crucial interface between the animal and its environment. This is especially true for bipedal and arboreal species living in a complex three-dimensional environment that likely induces strong selection on foot morphology. In birds, foot morphology is highly variable, with different orientations of the toes, making it a good model for the study of the role of functional, developmental, and phylogenetic constraints in the evolution of phenotypic diversity. Our data on the proportions of the phalanges analyzed in a phylogenetic context show that two different morphological patterns exist that depend mainly on habitat and toe orientation. In the anisodactyl foot, the hallux is the only backward-oriented toe and is enlarged in climbing species and reduced in terrestrial ones. Moreover, a proximo-distal gradient in phalanx size is observed depending on the degree of terrestriality. In the two other cases (heterodactyl and zygodactyl) that have two toes that point backward, the hallux is rather small in contrast to the other backward-pointing toe, which is enlarged. The first pattern is convergent and common among tetrapods and follows rules of skeletal development. The second pattern is unique for the clade and under muscle-morphogenetic control. In all cases, the functional result is the same tool, a pincer-like foot.

Anatomical Footprint of the Tibialis Anterior Tendon: Surgical Implications for Foot and Ankle Reconstructions

This study aimed to analyze precisely the dimensions, shapes, and variations of the insertional footprints of the tibialis anterior tendon (TAT) at the medial cuneiform (MC) and first metatarsal (MT1) base. Forty-one formalin-fixed human cadaveric specimens were dissected. After preparation of the TAT footprint, standardized photographs were made and the following parameters were evaluated: the footprint length, width, area of insertion, dorsoplantar location, shape, and additional tendon slips. Twenty feet (48.8%) showed an equal insertion at the MC and MT1, another 20 feet (48.8%) had a wide insertion at the MC and a narrow insertion at the MT1, and 1 foot (2.4%) demonstrated a narrow insertion at the MC and a wide insertion at the MT1. Additional tendon slips inserting at the metatarsal shaft were found in two feet (4.8%). Regarding the dorsoplantar orientation, the footprints were located medial in 29 feet (70.7%) and medioplantar in 12 feet (29.3%). The most common shape at the MT1 base was the crescent type (75.6%) and the oval type at the MC (58.5%). The present study provided more detailed data on the dimensions and morphologic types of the tibialis anterior tendon footprint. The established anatomical data may allow for a safer surgical preparation and a more anatomical reconstruction.

Morphological evaluation of Merkel cells and small lamellated sensory receptors in the equine foot

OBJECTIVE To examine the equine foot for the presence of sensory receptors including Merkel cells and small lamellated Pacinian-like corpuscles (SLPCs). SAMPLE Forefeet obtained from 7 horses following euthanasia for reasons other than foot disease. PROCEDURES Disarticulated feet were cut into either sagittal sections or cross sections and immersed in neutral-buffered 4% formalin. Following fixation, samples were obtained from the midline of the dorsal aspect of the hoof wall and from the frog (cuneus ungulae) between the apex and central sulcus. The formalin-fixed, paraffin-embedded hoof wall and frog sections were routinely processed for peroxidase immunohistochemistry and stained with H&E, Alcian blue, and Masson trichrome stains for histologic evaluation. RESULTS Sensory myelinated nerves and specific receptors were identified within the epidermal and dermal tissues of the equine foot including the hoof wall laminae, coronet, and frog. Merkel cells were identified with specific antisera to villin, cytokeratin 20, and protein gene product 9.5 in coronet epidermis and hoof wall. These cells were interspersed among basilar keratinocytes within the frog, coronary epidermis, and secondary epidermal laminae. The SLPCs were present within the superficial dermis associated with the central ridge of the frog (ie, frog stay). Numerous S100 protein and protein gene product 9.5 immunoreactive sensory nerves in close proximity to these receptors were present throughout the dermal tissues within both the frog and hoof wall. CONCLUSIONS AND CLINICAL RELEVANCE The presence of Merkel cells and SLPCs that are known to detect tactile and vibrational stimuli, respectively, further defined the diverse range of neural elements within the equine foot.

Histological, chemical and behavioural evidence of pedal communication in brown bears

Most mammals rely upon scent for intraspecific communication. As most bear species have large home ranges and are non-territorial, scent deposit while walking could be an effective way to communicate with conspecifics. Here, we investigate the existence of pedal glands in brown bears and their role in chemical communication from a histological, biochemical and behavioural perspective. We found eccrine glands in footpads, and prominent apocrine and sebaceous glands in the interdigital, metacarpal and metatarsal skin sections. Pedal scent contained 26 compounds including carboxylic acids, important constituents of mammalian secretions. Six of these compounds were exclusive for males. Finally, we describe a specific marking gait recorded in the field, mostly performed by males. Our study supports the existence of chemical communication through pedal marking in brown bears and suggests sex-coding potential of pedal scent.

Multiple regression based imputation for individualizing template human model from a small number of measured dimensions

Individual human models are usually created by direct 3D scanning or deforming a template model according to the measured dimensions. In this paper, we propose a method to estimate all the necessary dimensions (full set) for the human model individualization from a small number of measured dimensions (subset) and human dimension database. For this purpose, we solved multiple regression equation from the dimension database given full set dimensions as the objective variable and subset dimensions as the explanatory variables. Thus, the full set dimensions are obtained by simply multiplying the subset dimensions to the coefficient matrix of the regression equation. We verified the accuracy of our method by imputing hand, foot, and whole body dimensions from their dimension database. The leave-one-out cross validation is employed in this evaluation. The mean absolute errors (MAE) between the measured and the estimated dimensions computed from 4 dimensions (hand length, breadth, middle finger breadth at proximal, and middle finger depth at proximal) in the hand, 2 dimensions (foot length, breadth, and lateral malleolus height) in the foot, and 1 dimension (height) and weight in the whole body are computed. The average MAE of non-measured dimensions were 4.58% in the hand, 4.42% in the foot, and 3.54% in the whole body, while that of measured dimensions were 0.00%.

The relationship between arch height and foot length: Implications for size grading

OBJECTIVE

Medial longitudinal Arch Height is synonymous with classifying foot type and conversely foot function. Detailed knowledge of foot anthropometry is essential in the development of ergonomically sound footwear. Current Footwear design incorporates a direct proportionate scaling of instep dimensions with those of foot length. The objective of this paper is to investigate if a direct proportional relationship exists between human arch height parameters and foot length in subjects with normal foot posture.

METHOD

A healthy convenience sample of 62 volunteers was recruited to participate in this observational study. All subjects were screened for normal foot health and posture. Each subject's foot dimensions were scanned and measured using a 3D Foot Scanner. From this foot length and arch height parameters were obtained. Normalised ratios of arch height with respect to foot length were also calculated. The arch height parameters and the normalised arch ratios were used interchangeably as the dependent variables with the foot length parameters used as the independent variable for Simple Linear Regression and Correlation.

RESULTS

Analysis of foot length measures demonstrated poor correlation with all arch height parameters.

CONCLUSION

No significant relationships between arch height and foot length were found. The predictive value of the relationship was found to be poor. This holds significant implications for the current method of proportionate scaling of footwear in terms of fit and function to the midfoot region for a normative population.

Estimation of stature from radiographic measurement of foot dimensions: Truncated foot length may be more reliable than full foot length

Foot length has been shown to be a reliable dimension for estimation of stature. However, phalanges of the foot are very small bones and their length may not be proportional to person's stature. Thus, we hypothesized that foot length measured excluding the phalanges, the truncated foot length, may be more reliable in stature estimation than full foot length. This study, therefore, aimed at comparing the accuracy of the regression equations derived from the truncated foot length and the full foot length. The study recruited a sample of 32 young adults (16 males and 16 females) aged from 20 to 35 years. Lateral radiographs of the right feet were obtained for each subject in a bilateral standing position while maintaining equal weight on both feet. Standing height of the participants was measured with a stadiometer. Truncated foot length and full foot length were measured on the lateral radiographs of the foot. Independent t-test was used to check for mean differences in the dimensions between genders. Linear regression analysis was used to determine the equations for stature estimation. Intra and inter-observer reliability were calculated from four precision estimates: absolute technical error of measurement (aTEM), relative technical error of measurement (rTEM), coefficient of reliability (Rr) and coefficient of variation (Cv). All the dimensions measured were significantly larger in males than females. Linear regression equations were derived for estimation of stature using both the truncated foot length and full foot length. The regression equations derived from truncated foot length have larger correlation coefficient, coefficient of determination, adjusted coefficient of determination as well as smaller standard error of estimation than those derived from full foot length. All the precision estimates showed that the measurement errors are within acceptable limits. This study suggests that even if the full foot length is available, excluding the phalanges may give more accurate stature estimation.

Biological significance of dermal Merkel cells in development of cutaneous nerves in human fetal skin

We detected epidermal Merkel cells in 12-week fetuses with monoclonal antibodies (MAb) against simple epithelium keratin and epithelial membrane antigen. In 15-week fetuses these Merkel cells began to descend into the dermis and expressed nerve growth factor receptors (NGF-R). At approximately the same time, cutaneous nerves, as detected with an MAb against neurofilaments, extended from the subcutaneous trunk and branched to form the subepidermal nerve plexus. The expression of NGF-R on dermal Merkel cells preceded their connection with immunoreactive small nerves. Initially, most of these fine nerve endings were directed towards dermal Merkel cells. In 23-week fetuses the subepidermal nerve plexus was well developed and immunoreactive dermal Merkel cells began to disappear. At all stage of fetal development the epidermal Merkel cells did not strongly express NGF-R. We postulate that dermal Merkel cells play an inductive and a promotional role in development of the cutaneous nerve plexus in the upper dermis.

Unusually High Calcaneal Speed of Sound Measurements in Children with Small Foot Size

The purpose of this clinical note is to describe the performance of the Lunar Achilles Insight device in assessing bone quality at the calcaneus in 142 children between the ages of 5 and 11 y accessing healthcare in Johannesburg, South Africa. We observed an asymmetric bimodal distribution in speed of sound (SOS). The minor mode consisted of unusually high SOS values (≥1625 m/s), which were primarily observed among children with foot size <19 cm and height <119 cm. Cortical regions of the bone may have been inadvertently included in the region of interest for smaller feet, causing unusually high SOS values. The unusually high SOS values indicate that the validity of SOS in this device, as it is currently used for measuring bone quality in young children, is questionable. Future studies using this device in young children should develop new methodology to account for smaller foot size.

Correlation between Foot Arch Index and the Intensity of Foot, Knee, and Lower Back Pain among Pregnant Women in a South-Eastern Nigerian Community

OBJECTIVES

The aim of this study was to assess the arch height index of pregnant women and its correlation with foot pain, anterior knee pain, and lower back pain.

SUBJECTS AND METHODS

Two hundred and fifteen consenting pregnant women participated in this cross-sectional study. The arch height index was assessed from their foot prints, while pain intensity was rated on a numerical rating scale. Data were summarized with descriptive statistics and the Pearson correlation was used to determine correlations between the variables at p < 0.05.

RESULTS

Of the 215 pregnant women, 123 (57.2%) and 127 (59.9%) had low arch heights on the right and left feet, respectively, and the mean arch height indices were 0.27 ± 0.71 for the right foot and 0.28 ± 0.07 for the left foot. The prevalence of foot, knee, and lower back pain was 65 (30.2%), 43 (20.0%), and 93 (43.3%), respectively. The Pearson correlation analysis did not reveal any significant relationship (p > 0.05) between foot pain and each of the right (r = -0.010, p = 0.886) and left (r = 0.004, p = 0.955) arch indices as well as between knee pain and each of the right (r = 0.042, p = 0.536) and left (r = 0.045, p = 0.515) arch indices. A similar trend was observed for the lower back, which also did not show any significant relationship to each of the right (r = 0.026, p = 0.703) and left (r = 0.097, p = 0.157) arch indices.

CONCLUSION

The study participants had a high prevalence of low foot arches, indicating pes planus. Lower back pain was more common than foot and knee pain. The foot arch heights did not show any relationships between the intensities of foot, anterior knee, and lower back pain.

[Anatomical aspects of formation of corona phlebectatica]

The data concerning the anatomy of perforant veins of the foot can by no means be referred to as insufficiently known. At the same time, these descriptions are encountered rather rarely in the educational-and-methodical literature. To a certain degree, this may be explained by low pathogenetic significance of perforant veins of the foot; however, these data are required for the surgeon in carrying out both standard phlebectomy and sclerotherapy of subcutaneous varicose veins, especially if the zone of surgical intervention is situated immediately on the foot. Also, these data may be important for explaining clinical manifestations of chronic venous insufficiency. The present study was aimed at specifying the anatomical ground of formation of the corona phlebecatica and topography of perforant veins of the foot. The material for the study consisted of 15 lower extremities (cadaveric material) with no evidence of chronic venous diseases. The method of the study - anatomical dissection. From 4 to 6 perforant veins were found on the medial surface of the foot. They directly connected the medial marginal vein and vv. plantaris medialis. From 2 to 3 perforant veins were found on the lateral surface of the foot. They connected directly the lateral marginal vein and vv. plantaris lateralis. Topographically perforant veins pass behind the muscles of the lateral group of the foot, along the lateral intermuscular septum. Perforant veins of each group were found to have lateral affluents part of which independently drained the integumentary tissues of the lateral surfaces of the foot, and part formed anastomoses with the superficial venous plantar net. This makes it possible to characterize perforant veins not only as anastomoses connecting subcutaneous rear venous net with deep veins of the foot and with the superficial plantar net, but also as independently draining vessels. Besides, in the majority of cases, nearby a perforant vein we managed to isolate an artery and a nerve branchlet, originating from a. plantaris and n. plantaris. Hence, perforant veins of the medial and lateral surfaces of the foot constitute the anatomical ground for formation of the corona phlebectatica and are component parts of the neurovascular bundle (vein-artery-nerve).

Estimation of stature by using the dimensions of the right hand and right foot in Han Chinese adults

The Han Chinese people are the main ethnic group in China and the largest ethnic group in the world. The dimensions of the hands and feet have been successfully used for the estimation of stature. A total of 26,927 healthy adult subjects, comprising 13,221 men and 13,706 women, were recruited. The survey samples were chosen through random cluster sampling. The mean values were significantly higher in men than those in women for all measurements (P<0.001). All the measurements showed a statistically significant correlation with stature (P<0.01). The combination of the right hand length and the right foot length was the best predictor of stature because it had the lowest standard error of estimate. The use of multiple regression equations yielded better results than did the use of linear regression equations. The accuracy of stature prediction ranged from ±4.81 to ±6.39 cm. The present study was of great importance with regards to improving the physical anthropology database of ethnic groups in China.

Perception of Large Change in Distribution of Heel Pressure during Backward Leaning

We investigated the perception of the large change in distribution of heel pressure during backward leaning. Subjects were 12 healthy adults who reported perceiving a large change in distribution of heel pressure by a handheld switch while leaning voluntarily backward on a sole pressure analyzer and on a heel force plate. The large change was indicated at the center of heel pressure. Morphological features of the foot were measured on an X-ray film. The position of heel pressure center and the morphological locations were represented as relative distance (%) from the hindmost point of the heel, where foot length represented 100%. Center of heel pressure changed largely during backward leaning, and the position at which large change occurred was the same as that of the peak of the distribution. Large change in distribution of heel pressure was perceived at a position 1.3% posterior from that at which the large change actually occurred. The correlation between perceived and actual positions was significant ( r = .91). Significant correlations were found between position of a large change of center and locations of heel pressure of both the lateral process of the calcaneal tuberosity and the top of the talar trochlea ( r = .86; r = .11, respectively). The results indicate that subjects accurately perceive large changes in distribution of heel pressure and that the morphological features of the foot contribute to these changes.