The measurement of the medial longitudinal arch in children

Predictors of flatfoot in 11-12-year olds: a longitudinal cohort study

BACKGROUND

The structures around the navicular bones, which constitute the medial longitudinal arch, develop by 10 years of age. While navicular bone height is often emphasized in the assessment of flatfoot, three-dimensional (3D) evaluations, including those of structural parameters during inversion, have rarely been investigated. If the development of flatfoot during the growth process could be predicted, appropriate interventions could be implemented. Therefore, in this longitudinal cohort study, we developed a system, utilizing smartphones, to measure the 3D structure of the foot, performed a longitudinal analysis of changes in midfoot structures in 124 children aged 9-12 years, and identified factors influencing the height of the navicular bone. The foot skeletal structure was measured using a 3D system.

RESULTS

Over 2 years, foot length and instep height increased during development, while navicular height decreased. The 25th percentile of the instep height ratio and navicular height ratio at ages 9-10 years did not exceed those at ages 11-12 years, with percentages of 17.9% and 71.6%, respectively, for boys, and 15.8% and 49.1%, respectively, for girls. As the quartiles of the second toe-heel-navicular angle (SHN angle) increased at ages 9-10 years, the axis of the bone distance (ABD) and SHN angles at ages 11-12 years also increased, resulting in a decrease in the navicular height ratio. A significant inverse correlation was found between changes in SHN angle and navicular height ratio. These findings indicate that the navicular bone rotation of the midfoot is a predictor of the descent of the navicular bone.

CONCLUSIONS

This study revealed that some children exhibit decreases in navicular bone height with growth. As a distinct feature, the inversion of the navicular bone promotes flattening of the midfoot. Thus, this study provides insights into changes in midfoot development in children and provides an effective evaluation index.

Biomechanical investigation of a custom-made insole to decrease plantar pain of children with flatfoot: A technical note

OBJECTIVE

The abnormal plantar pressure of flatfoot patients is a common condition. The main objective of the present study was to investigate the effect of custom-molded insole on the plantar pain of flatfoot METHODS: 105 patients (representing 174 feet) participated in evaluating a custom-made orthotic insole from June 2018 to March 2019. The height of the navicular tubercle (HNT) and the deflection angle of calcaneus (DAC) in flatfoot patients after using orthotic insoles for 6 months were recorded by X-ray imaging and scanning measurements. Plantar pressure on metatarsals 1-5 was measured by using an RSscan system RESULTS: Without the use of an orthotic insole, mean HNT was 0.99±0.34 cm and mean DAC was 20.0 ± 3.78 ° during the bearing weight. After using the insole, mean HNT and DAC values reduced to 0.87±0.30 cm and 14.3 ± 3.45 °, respectively (P < 0.05). Hindfoot plantar pressure did not change significantly (P > 0.05). Furthermore, pressure at metatarsals 1-3 decreased by 48.5 %, 45.6 %, and 14.3 %, respectively; that at metatarsals 4-5 increased by 33.3 % and 137.5 %, separately, when using the custom-made insole CONCLUSIONS: Visual analog scale score for plantar pain was significantly reduced. These findings indicate that metatarsal pain of flatfoot patients might be the cause of load imbalance in plantar foot.

Foot morphology and correlation with lower extremity pain in Japanese children: A cross-sectional study of the foot posture Index-6

BACKGROUND

Abnormal foot morphology in children and adolescents is a possible risk factor for lower extremity pain. Foot posture index-6 (FPI-6) is a valid and reliable tool to assess foot morphology. However, the normative data on the age distribution for FPI-6 in Asian children and adolescents are still minimal. Further, the correlation of FPI-6 with lower extremity pain is poorly understood. We aimed to investigate the normative distribution for FPI-6 and the relationship between FPI-6 scores and knee and heel pain in Japanese children.

METHODS

We included 2569 Japanese children, aged 9-15 years, at a single school from 2016 to 2018. We summarized the age distribution of children and their mean bilateral FPI-6 scores. Additionally, we assessed the tenderness at the apophysis or tendon insertions at the knee and heel. We performed a cross-sectional analysis to investigate the correlations between FPI-6 scores and sex, age, and knee and heel pain for the data obtained each year.

RESULTS

The mean FPI-6 score was 3.1 ± 2.4, 3.4 ± 2.0, and 3.2 ± 1.9 for the left foot and 3.0 ± 2.4, 3.2 ± 1.9, and 3.1 ± 1.9 for the right foot in 2016, 2017, and 2018, respectively. Boys tended to have higher scores than girls, and the FPI-6 score of the left foot was significantly higher than that of the right foot (p < 0.05). There was no correlation between FPI-6 scores and knee and heel pain.

CONCLUSION

Children and adolescents between 9 and 15 years of age have neutral to slightly pronated foot morphology and an average FPI-6 score of 3.0-3.4. In addition, there was no relationship between foot morphology and knee and heel pain. This normative distribution for FPI-6 in Japanese children could serve as a reference value for future research and clinical evaluation.

Children's foot parameters and basic anthropometry - do arch height and midfoot width change?

The aims of this study were as follows: (1) to assess how foot posture and morphology assessments change according to body mass index (BMI) status; (2) to determine which body composition parameter (BMI or waist circumference) correlates better with the foot posture index (FPI), arch height index (AHI), and midfoot width (MFW) in children. Foot morphometry (FPI, AHI, and MFW) and body composition (BMI and waist circumference (WC)) were assessed in a cross-sectional study of 575 children (mean age = 7.42 ± 1.67 years; 53.27% female). When comparing BMI groups, an increase of 8.3% in AHI and 13.6% in MFW (both p < 0.0001) was seen. In linear regression analyses, BMI and WC were positively associated with MFW explaining together 64.8% of its variance. Noteworthy, MFW is the most related to body composition parameters.

CONCLUSION

Foot morphology assessed by FPI, AHI, and MFW differs among BMI categories in children. Noteworthy, WC correlates better with foot measures than does the more commonly used BMI, and more importantly the MFW is the foot measure best explained by children's body weight. Since foot morphometry is different among different BMI groups, children would benefit from shoes with different patterns (thinner and wider), as well as a good system to adjust midfoot height.

WHAT IS KNOWN

• Children who are overweight and obese have flatter feet, when assessed using footprints. • Up to 72% of people have incorrectly fitted shoes.

WHAT IS NEW

• Children with underweight have thinner and flatter feet than children with normal weight, while children with overweight and obesity have wider and higher arched feet. • Body weight is related to foot shape, which has relevance for footwear manufacturers.

Age-related changes in three-dimensional foot motion during barefoot walking in children aged between 7 and 11 years old

BACKGROUND

The biomechanical complexity of children's feet changes throughout childhood, yet kinematic development of the feet is poorly understood. Further work exploring the kinematic profile of children's feet would be beneficial to help inform our understanding of the typical development of children's feet.

RESEARCH QUESTION

Do three-dimensional segmental kinematics of the feet during gait relate to age in a sample of children age 7-11 years?

METHODS

This study was a secondary analysis of an existing database representing one hundred and twenty-one children age 7 - 11 years (90 male, 31 female; mean ± SD: age 9.57 ± , 1.17 years, height 1.37 ± 0.08 m, body mass 35.61 ± 9.33 kg). Fifteen, 9 mm retroreflective markers were attached to the right shank and foot of each participant in, line with the 3DFoot model. Multi-segmental joint kinematics were collected during barefoot walking. Sagittal, frontal, and transverse planar motion was described for the shank-calcaneus, calcaneus-midfoot, and midfoot-metatarsals segment of the right foot. Principal component analysis (PCA) was used to reduce the major modes of variation in the data to fully explore foot segment motion over the entire gait cycle. Correlations and multiple regression between PCA outputs with age, and potential confounding factors are presented.

RESULTS

Significant positive correlations were found between age and greater calcaneus, dorsiflexion, midfoot inversion and adduction, and metatarsal dorsiflexion, plantarflexion and abduction. There were no significant confounding effects of height, body mass, walking speed or gender on the relationships between age and PCA outputs.

SIGNIFICANCE

The findings from this study demonstrated a relationship between foot kinematics and age suggesting that the development of foot kinematics is ongoing until at least the age of 11 years. This work offers a comprehensive data set of inter-segmental kinematics which helps to advance understanding of the development of the pediatric foot.

Measurement of the Developing Foot in Shod and Barefoot Paediatric Populations: A Narrative Review

The theory that footwear may change foot shape dates back 100 years. Since this period, research has revealed the anatomical and functional consequences that footwear can cause to the foot. Children’s feet remain malleable as they undergo developmental changes until adolescence, which is why childhood is arguably a crucial period to understand how footwear can affect natural foot development. This review explored the development of the foot in children and adolescents and the methods used to measure the different foot structures; it comments on the key issues with some of these methods and gives direction for future research. Various internal and external factors can affect foot development; the main factors are age, gender, ethnicity, body mass index (BMI) and footwear habits. Research on how footwear can affect foot development has increased over the years and the final section of this review aimed to unpick the findings. Studies investigating the influence of footwear habits on foot length and width have established inconsistent findings. Many of the studies in the review did not control for internal and external factors that can affect foot development. There was also a limited number of studies that investigated hallux valgus angle and muscle strength differences in those with different footwear habits. Moreover, multiple studies in the final section of this review did not successfully examine the footwear habits of the participants and instead used observations or self-assessments, which is a major limitation. Future research should examine footwear behaviors and other confounding factors when investigating the development of the foot in children and adolescents. Moreover, researchers should critically evaluate the methods used to quantify the different structures of the foot to ensure valid and reliable parameters are being used.

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

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

Paediatric flat foot and foot dimension in Central Anatolia

Background

Information on the foot structures of Central Anatolian children is limited. Foot structures of children aged 6–10 years were shown to be different according to sex and increasing age.

Objective

This study aimed to compare the foot anthropometric values by age and sex and collect the foot anthropometric data to reveal the relationship between pes planus and pes cavus in the arches of children according to age.

Methods

Footprints of 335 children (180 boys and 155 girls) aged 6–10 years were taken by the pedigraph method and evaluated using 18 different parameters. The TFL (Truncated foot length), FL (foot length), Arch Index, Chippaux Smirak Index, Staheli Arc Index, and foot rotation values of the children were examined. To examine the relationship between the parameters, normality values were examined. Independent samples t-test was used to analyze sex differences in terms of foot size and shape.

Results

Correlations between other parameters were determined using the correlations analysis method. TFL, metatarsal circumference, and FL were strongly correlated with age in the children. Foot rotation increased with body mass index in the girls compared to that in the boys. According to the evaluation results with the classification made with the Staheli arch index, 63.3% pes planus, 9.8% pes cavus and 27.7% of the normal arch structure were identified.

Conclusions

Planning shoe production accordingly will contribute to the development of healthy feet in children. This article focused on foot structures of in Central Anatolia and to identify early foot deformities in children. This study found that the length of the TFL was smaller in boys than in girls.

Importance of toe flexor strength in vertical jump performance

This study investigated whether toe flexor strength and foot arch height were related to force components during the ground contact phase in vertical jump performance. The toe flexor strength, foot arch height and vertical jump performance were studied in 31 healthy young men. For the measurement of toe flexor strength, participants explosively exerted maximum force on a toe grip dynamometer. The maximum isometric force (Fmax) and the rate of force development (RFD) of the toe flexor strength were evaluated. Foot arch height was assessed as the distance between the navicular tuberosity and the floor. Fmax and foot arch height were normalized by body mass (rFmax) and height, respectively. Three types of vertical jumps without arm swing were performed on a force plate: a squat jump (SJ), a countermovement jump (CMJ), and a rebound jump (RJ). Fmax, rFmax and RFD of the toe flexor strength were positively correlated with the vertical jump height in the SJ (r = 0.408, r = 0.452, r = 0.514) and CMJ (r = 0.377, r = 0.444, r = 0.548) and the rebound jump index in the RJ (r = 0.549, r = 0.582, r = 0.575); however, foot arch height was not correlated with the vertical jump performance, and it was only significantly correlated with the minimum ground reaction force relative to body weight during the unloading phase of the CMJ (r = -0.366). These results suggest that the toe flexor strength is an important parametre for enhancing the jump performance.

Evaluation of the paediatric foot using footprints and foot posture index: A cross-sectional study

AIM

Footprints have long been used as proxy measures of foot morphology, yet there is little consensus regarding footprints versus measures of foot posture, which address foot anatomy directly. Foot posture in children can be a confusing clinical presentation, with previous studies both supporting and refuting the relationship between childhood obesity and flat feet. The aim of this study was to determine the relationship between footprints and foot posture in children.

METHODS

A total of 316 school children (153 boys, 163 girls) from Spain, aged 6-9 years, were assessed for both footprint (Clarke's angle (CA)), by Tecniwork Pedrograph Plate, and foot posture (foot posture index (FPI)) measures, with participants barefoot, in a relaxed standing position, on a 50-cm elevated platform.

RESULTS

A negative correlation was found between FPI and footprints (CA) (rho = -0.505 left, P < 0.001) and by gender (rho = -0.457 for the left foot in girls, P < 0.001; rho = -0.548 for the left foot in boys, P < 0.001). The children with pes cavus according to the CA (73.3%) had normal feet according to FPI, and the children with severe pes planus according to the CA (78.98%) had pronated feet according to the FPI. A χ² test showed these results to be statistically significant (P > 0.001).

CONCLUSIONS

An inverse relationship between CA and FPI was identified, that is, the greater the FPI, the smaller the CA, but not all pronated foot are planus feet and not all cavus feet are supinated feet. Footprints may overestimate and misguide paediatric foot posture concerns.

Three-dimensional foot shape analysis in children: a pilot analysis using three-dimensional shape descriptors

BACKGROUND

Existing clinical measures to describe foot morphology are limited in that they are commonly two-dimensional, low in resolution and accuracy, and do not accurately represent the multi-planar and complex changes during development across childhood. Using three-dimensional (3D) scanner technology provides the opportunity to understand more about morphological changes throughout childhood with higher resolution and potentially more relevant 3D shape measures. This is important to advance the prevailing arguments about the typical development of children's feet and inform the development of appropriate clinical measures. 3D shape descriptors derived from 3D scanning can be used to quantify changes in shape at each point of the 3D surface. The aim of this study was to determine whether 3D shape descriptors derived from 3D scanning data can identify differences in foot morphology between children of different ages.

METHODS

Fifteen children were recruited from three age groups (2, 5, and 7 years of age). Both feet were scanned in bipedal stance, using the Artec Eva (Artec Group, Luxembourg, Luxembourg) hand-held scanner. Three dimensional shape descriptors were extracted from the 3D scans of the right foot, to create histograms for each age group and heat maps of representative participants for comparison.

RESULTS

There were changes to the dorsal, medial and lateral surfaces of the feet with age. The surfaces became less round along with an increase in indented areas. This is supported by the heat maps which demonstrated that the surfaces of the anatomical landmarks (e.g. the malleoli and navicular tuberosity) became more rounded and protruding, with indented surfaces appearing around these landmarks. On the plantar surface, the concavity of the midfoot was evident and this concavity extended into the midfoot from the medial aspect as age increased.

CONCLUSIONS

The findings of this study indicated that with increasing age the foot becomes thinner in 3D, with bony architecture emerging, and the medial longitudinal arch (MLA) increases in area and concavity. Three-dimensional shape descriptors have shown good potential for locating and quantifying changes in foot structure across childhood. Three-dimensional shape descriptor data will be beneficial for understanding more about foot development and quantifying changes over time.

Toe flexor strength is not related to postural stability during static upright standing in healthy young individuals

BACKGROUND

The human foot has adapted specifically to support body weight when standing upright. At the base of the postural control system, the unique arch structure of the foot still has an uncertain role in human upright standing. Because the toe flexor muscles help to support the foot arches, they might be an important contributor to postural stability. However, no research has identified the influence of the toe flexor strength or the foot arch height on postural stability in static upright standing.

RESEARCH QUESTION

The aim of this study was to examine whether the toe flexor strength and the foot arch height were related to postural stability in static standing in healthy young individuals.

METHODS

Fifty healthy young individuals were recruited into this cross-sectional study. Toe flexor strength was measured using a toe grip dynamometer, and it was normalised by body mass (rTFS). Foot arch height was assessed as the distance between the navicular tuberosity of the foot and the floor, and it was normalised by height (rFAH). Postural stability was evaluated using the path of the centre of pressure (COP) during double-leg standing with eyes open and single-leg standing with eyes open.

RESULTS

rTFS and rFAH were 2.6 ± 0.8 N/kg and 2.8 ± 0.4%, respectively, and they were not significantly correlated (r = 0.094), indicating that they were independent variables. The results of Pearson's correlation analysis revealed that any body size related variables (height, body mass, BMI) were not significantly correlated with COP variables under either double-leg or single-leg standing, rTFS was not significantly correlated with COP variables under either double-leg or single-leg standing and rFAH was not significantly correlated with COP variables under double-leg standing.

SIGNIFICANCE

Toe flexor strength has no significant role in maintaining postural stability during static upright standing.

PREVALENCE OF FOOT DEFORMITIES IN YOUNG SCHOOLCHILDREN IN SLAVONIA

The aim of this study was to determine the occurrence of foot deformity in urban children, as well as possible generational and gender differences using graphic and angular methods. The sample of study subjects included 426 1^st to 4^th grade schoolchildren (7 to 10 years of age). Out of the total number of schoolchildren, 181 children (88 boys and 93 girls) were measured in 2005, and 244 children (122 boys and 123 girls) in 2011. The results indicated that the largest number of children had no noticeable foot deformity, flat foot in particular. Likewise, there were no gender differences in the occurrence of flat foot and no statistically significant differences in the incidence between the children measured in 2005 and 2011. Due to the problems that foot deformities could cause, it is necessary to continue monitoring foot arches of young schoolchildren in order to intervene on time and prevent the occurrence of deformities by appropriate therapeutic procedures.

Understanding the foot's functional anatomy in physiological and pathological conditions: the calcaneopedal unit concept

BACKGROUND

A thorough review of the available orthopaedic literature shows significant controversies, inconsistencies and sparse data regarding the terminology used to describe foot deformities. This lack of consensus on terminology creates confusion in professional discussions of foot anatomy, pathoanatomy and treatment of deformities. The controversies apply to joint movements as well as static relationships between the bones.

DESCRIPTION

The calcaneopedal unit (CPU) is a specific anatomical and physiological entity, represented by the entire foot excepted the talus. The calcaneus, midfoot and forefoot are solidly bound by three strong ligaments that create a unit that articulates with the talus. The movement of the CPU is complex, as it rotates under the talus, around the axis of Henke that coincides with the talo-calcaneal ligament of Farabeuf.This calcaneopedal unit is deformable. It is compared with a twisted plate, able to adapt to many physiological situations in standing position, in order to acheive a plantigrade position.Moreover, the calcaneopedal unit and the talo-tibiofibular complex are interdependent; rotation of the latter produces morphologic modifications inside the former and vice versa.

PURPOSE

This paper is a review article of this concept and of its physiopathological applications.

Evaluating the Medial Longitudinal Arch of the Foot: Correlations, Reliability, and Accuracy in People With a Low Arch

BACKGROUND

The medial longitudinal arch of the foot is a variable structure, and a decrease in its height could affect several functions and increase the risk of injuries in the lower limbs. There are many different techniques for evaluating it.

OBJECTIVE

The objective of this study was to evaluate the correlations of the Navicular Drop Test, several footprint parameters, and the Foot Posture Index-6 in people with a low medial longitudinal arch. Intrarater reliability and interrater reliability were also estimated.

DESIGN

This was a repeated-measures, observational descriptive study.

METHODS

Seventy-one participants (53.5% women; mean age = 24.13 years; SD = 3.41) were included. All of the parameters were collected from the dominant foot. The correlation coefficients were calculated. The reliability was also calculated using the intraclass correlation coefficient, 95% CI, and kappa coefficient.

RESULTS

Statistically significant correlations were obtained between the Navicular Drop Test and the footprint parameters, with r absolute values ranging from 0.722 to 0.788. The Navicular Drop Test and the Foot Posture Index-6 showed an excellent correlation (Spearman correlation coefficient = 0.8), and good correlations (Spearman correlation coefficient = |0.663-0.703|) were obtained between the footprint parameters and the Foot Posture Index-6. Excellent intrarater reliability and interrater reliability were obtained for all of the parameters.

LIMITATIONS

Radiographic parameters, the gold standard for evaluating the medial longitudinal arch height, were not used. In addition, the results of this research cannot be generalized to people with normal and high medial longitudinal arches.

CONCLUSIONS

In participants with a low medial longitudinal arch, the Navicular Drop Test showed significant correlations with footprint parameters; correlations were good for the arch angle and Chippaux-Smirnak Index, and excellent for the Staheli Index. The Foot Posture Index-6 showed an excellent correlation with the Navicular Drop Test and a good correlation with the footprint parameters evaluated. All of the parameters showed high reliability.

Force-generating capacity of the toe flexor muscles and dynamic function of the foot arch in upright standing

The muscle and tendon complex of the foot helps to support the foot arch and generates the muscle force of the foot. The present study investigated the force-generating capacity of the toe flexor muscles and the dynamic function of the foot arch when standing upright, and the relationships between these indices. The maximum toe flexor force and foot arch height in the sitting and standing positions were studied in the left and right feet of 224 healthy young individuals. To measure the maximum isometric force of the toe flexor muscles, the subjects exerted maximum force on a toe grip dynamometer. Measurements were repeated three times with at least a 1-min rest period between bouts, and the maximum value among the measurements for each foot was used for further analysis. The absolute value of the toe flexor strength was normalised by body mass. The foot arch height was measured the distance between the tuberosity of the navicular bone and the floor, and normalised by height. The relative foot arch height difference between the sitting and standing positions was evaluated as the foot arch dynamics. The maximum isometric toe flexor strength was 42% higher in the standing position than in the sitting position. There was no relationship between the relative toe flexor strength and the relative foot arch height in either the sitting or standing positions; however, the relative increase in toe flexor strength from sitting to standing (the force amplification factor) was related to the foot arch dynamics, and the flexible foot arch showed a greater increase in the toe flexor strength from sitting to standing compared with the strength in the stiff foot arch. The results of this study suggest that the force-generating capacity of the toe flexor muscles is augmented by bodyweight bearing in upright standing. Additionally, the force amplification mechanism is mechanically regulated by the dynamic function of the foot arch in conjunction with the stretching of the muscle-tendon complex of the foot.

Medial Longitudinal Arch: Accuracy, Reliability, and Correlation Between Navicular Drop Test and Footprint Parameters

OBJECTIVE

The purpose of this study was to evaluate the correlation among the navicular drop test, the arch angle, the Staheli index and the Chippaux-Smirak index. The reliability and the correlation among the footprint parameters were also estimated.

METHODS

A cross-sectional study (n = 86; 59.3% women; 27.8 years, standard deviation: 4.8 years) was carried out. The navicular drop test was evaluated and footprint parameters using a plantar pressure platform were recorded in the dominant foot. Pearson correlation coefficients, intraclass correlation coefficient, standard error of measurement, and minimum detectable change were calculated.

RESULTS

Both intrarater and interrater reliability were excellent for all the parameters evaluated (intraclass correlation coefficients > 0.880). Statistically significant correlations existed between the navicular drop test and footprints parameters (arch angle = 0,643; Staheli index = 0.633; Chippaux-Smirak index = 0.614). The footprint parameters had excellent correlation with each other (0.838-0.881). The navicular drop test and the footprint parameters studied were reproducible and thus had excellent reliability.

CONCLUSION

The correlations obtained between the navicular drop test and the footprint parameters evaluated were good. The navicular drop test appears to be a reproducible, valid, and simple test for evaluating medial longitudinal arch height, having fewer disadvantages than using footprint parameters.

Estimation of stature and body weight in Slovak adults using static footprints: A preliminary study

The stature and the body weight as part of the biological profile can aid the personal identification. The dimensions of the human foot, as well as the footprint, can be used for the prediction due to the existence of its positive correlation with the stature and body weight. Five diagonal axes and ball breadth of bilateral static footprints of 132 young Slovak adults were obtained. All diameters were larger in a male group than female group. No bilateral differences were found except the first diagonal axis and ball breadth. A positive correlations between the selected footprint diameters with the stature (r = 0.37-0.64) and the body weight (r = 0.29-0.71) were confirmed. The linear and multiple regression prediction equations were developed. A stature prediction equation using the most lateral diameters (the fourth and fifth diagonal axis) exhibited the highest accuracy ranging from 4 to 7.5 cm. Similar results were found for the body weight estimation of the male and mixed group. In the female group, the most medial axis (first and second) exhibited the highest accuracy. The body weight estimation accuracy ranges from 9.09 to 11.09 kg. The real and predicted stature and body weight were compared and found differences were lower than calculated SEEs. Thresholds and prediction trend of under- or overestimation was identified. The results of the present study show that selected measurements of static footprints could be used to predict stature and body weight but should be applied only for Slovaks due to population specificity.

Paediatric flexible flat foot: how are we measuring it and are we getting it right? A systematic review

BACKGROUND

Flexible flat foot is a normal observation in typically developing children, however, some children with flat feet present with pain and impaired lower limb function. The challenge for health professionals is to identify when foot posture is outside of expected findings and may warrant intervention. Diagnoses of flexible flat foot is often based on radiographic or clinical measures, yet the validity and reliability of these measures for a paediatric population is not clearly understood. The aim of this systematic review was to investigate how paediatric foot posture is defined and measured within the literature, and if the psychometric properties of these measures support any given diagnoses.

METHODS

Electronic databases (MEDLINE, CINAHL, EMBASE, Cochrane, AMED, SportDiscus, PsycINFO, and Web of Science) were systematically searched in January 2017 for empirical studies where participants had diagnosed flexible flat foot and were aged 18 years or younger. Outcomes of interest were the foot posture measures and definitions used. Further articles were sought where cited in relation to the psychometric properties of the measures used.

RESULTS

Of the 1101 unique records identified by the searches, 27 studies met the inclusion criteria involving 20 foot posture measures and 40 definitions of paediatric flexible flat foot. A further 18 citations were sought in relation to the psychometric properties of these measures. Three measures were deemed valid and reliable, the FPI-6 > + 6 for children aged three to 15 years, a Staheli arch index of > 1.07 for children aged three to six and ≥ 1.28 for children six to nine, and a Chippaux-Smirak index of > 62.7% in three to seven year olds, > 59% in six to nine year olds and ≥ 40% for children aged nine to 16 years. No further measures were found to be valid for the paediatric population.

CONCLUSION

No universally accepted criteria for diagnosing paediatric flat foot was found within existing literature, and psychometric data for foot posture measures and definitions used was limited. The outcomes of this review indicate that the FPI - 6, Staheli arch index or Chippaux-Smirak index should be the preferred method of paediatric foot posture measurement in future research.

Characteristics of Plantar Pressures and Related Pain Profiles in Elite Sprinters and Recreational Runners

BACKGROUND

Plantar pressure measurement is effective for assessing plantar loading and can be applied to evaluating foot performance. We sought to explore the characteristics of plantar pressures in elite sprinters and recreational runners during static standing and walking.

METHODS

Arch index (AI) values, regional plantar pressure distributions (PPDs), and footprint characteristics were examined in 80 elite sprinters and 90 recreational runners using an optical plantar pressure measurement system. Elite sprinters' pain profiles were examined to evaluate their most common pain areas.

RESULTS

In recreational runners, AI values in males were in the normal range and in females were high arch type. The AI values were significantly lower in elite sprinters than in recreational runners. In elite sprinters, particularly males, the static PPD of both feet was higher at the medial metatarsal bone and the lateral heel and lower at the medial and lateral longitudinal arches. Elite male sprinters' PPD of both feet was mainly transferred to the medial metatarsal bone and decreased at the lateral longitudinal arch and the medial heel during the midstance phase of walking. The lateral knee joint and biceps femoris were the most common sites of musculoskeletal pain in elite sprinters.

CONCLUSIONS

Elite sprinters' AI values could be classified as high arches, and their PPD tended to parallel the features of runners and high-arched runners. These findings correspond to the profile of patellofemoral pain syndrome (PFPS)-related plantar pressure. The pain profiles seemed to resonate with the symptoms of high-arched runners and PFPS. A possible link between high-arched runners and PFPS warrants further study.

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.

The Effect of Arch Height and Material Hardness of Personalized Insole on Correction and Tissues of Flatfoot

Flat foot is one of the common deformities in the youth population, seriously affecting the weight supporting and daily exercising. However, there is lacking of quantitative data relative to material selection and shape design of the personalized orthopedic insole. This study was to evaluate the biomechanical effects of material hardness and support height of personalized orthopedic insole on foot tissues, by in vivo experiment and finite element modeling. The correction of arch height increased with material hardness and support height. The peak plantar pressure increased with the material hardness, and these values by wearing insoles of 40° were apparently higher than the bare feet condition. Harder insole material results in higher stress in the joint and ligament stress than softer material. In the calcaneocuboid joint, the stress increased with the arch height of insoles. The material hardness did not apparently affect the stress in the ankle joints, but the support heights of insole did. In general, insole material and support design are positively affecting the correction of orthopedic insole, but negatively resulting in unreasonable stress on the stress in the joint and ligaments. There should be an integration of improving correction and reducing stress in foot tissues.

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.

Reliability of the Arch Height Index as a Measure of Foot Structure in Children

PURPOSE

To determine the intrarater and interrater reliability of the arch height index (AHI) in children developing typically. The AHI is tested with a device that measures foot structure.

METHODS

Thirty children, ages 6 to 12 years, participated for a total of n = 60 feet. The AHI measurements were taken by 2 investigators in sitting and standing and repeated twice by each investigator in a single visit. Intrarater and interrater reliabilities were determined using intraclass correlation coefficient (ICC) (2,1) statistical analysis.

RESULTS

The mean age was 9.61 ± 1.96 years. The intrarater and interrater reliability had an ICC 0.76 or more in both sitting and standing. The average AHI value was 0.36 ± 0.02 in sitting and 0.32 ± 0.02 in standing.

CONCLUSIONS

Pediatric therapists, physicians, and orthotists should consider using the AHI as an objective measure to be used for research, to assess foot structure, monitor change over time, and assist with treatment planning in children.

The effects of being habitually barefoot on foot mechanics and motor performance in children and adolescents aged 6-18 years: study protocol for a multicenter cross-sectional study (Barefoot LIFE project)

Background

Barefoot locomotion has evoked an increasing scientific interest with a controversial debate about benefits and limitations of barefoot and simulated barefoot walking and running. While most current knowledge comes from cross sectional laboratory studies, the evolutionary perspective suggests the importance of investigating the long-term effects. Observing habitually barefoot populations could fill the current gap of missing high quality longitudinal studies. Therefore, the study described in this design paper aims to investigate the effects of being habitually barefoot on foot mechanics and motor performance of children and adolescents.

Methods

This study has a cross-sectional, binational design and is part of the “Barefoot Locomotion for Individual Foot- and health Enhancement (Barefoot LIFE)” project. Two large cohorts (n_(total) = 520) of healthy children and adolescents between 6 and 18 years of age will be included respectively in Germany and South Africa. A barefoot questionnaire will be used to determine habitually barefoot individuals. The testing will be school-based and include foot mechanical (static arch height index, dynamic arch index, foot pliability) and motor performance (coordination, speed, leg power) outcomes. Gender, BMI and level of physical activity will be considered for confounding.

Discussion

The strength of this study is the comparison of two large cohorts with different footwear habits to determine long-term effects of being habitually barefoot on foot mechanics and motor performance.

Electronic supplementary material

The online version of this article (doi:10.1186/s13047-016-0166-1) contains supplementary material, which is available to authorized users.

Foot dimensions and morphology in healthy weight, overweight and obese males

BACKGROUND

Overweight and obesity are increasing in prevalence. However, despite reports of poor foot health, the influence of obesity and overweight on adult foot morphology has received limited attention. The objective of this work is to accurately and appropriately quantify the foot morphology of adults who are overweight and obese.

METHODS

The foot morphology of 23 healthy weight (BMI=22.9kg.m(-2)), overweight (27.5kg.m(-2)) and obese (32.9kg.m(-2)) age (60years) matched males was quantified using a 3D scanner (all size UK 9). Data analysis computed normalised (to foot length) standard anatomical measures, and widths, heights and circumferences of 31 evenly spaced cross-sections of right feet.

FINDINGS

Anatomical measures of foot, ball and heel width, ball and heel circumference and ball height were all greater in the obese group than the healthy weight (P<0.05). Cross-sectional measures were significantly wider than the healthy group for the majority of measures from 14 to 67% (P=0.025-1.000) of heel-to-toe length. Also, the obese group had significantly higher midfoot regions (P=0.024-0.025). This increased foot height was not evident from anatomical measures, which were not sensitive enough to detect dimensional differences in this foot region.

INTERPRETATION

Feet of obese adults differ from healthy and overweight individuals, notably they are wider. Data needs to avoid reliance upon discrete anatomical landmarks to describe foot morphology. In the obese, changes in foot shape do not coincide with traditional anatomical landmarks and more comprehensive foot shape data are required to inform footwear design.

Medial Longitudinal Arch Development of Children Aged 7 to 9 Years: Longitudinal Investigation

BACKGROUND

It is unclear at what age the medial longitudinal arch (MLA) of the foot becomes stable in children. The influence of footwear on MLA development also is unknown.

OBJECTIVE

The purpose of this study was to examine the MLA development of children using a longitudinal approach. The relationship between wearing different types of footwear and MLA development also was explored longitudinally.

DESIGN

This was a longitudinal cohort observational study.

METHODS

The MLA of 111 healthy children (mean age=6.9 years, SD=0.3) was evaluated using 3 parameters (arch index [AI], midfoot peak pressure [PP], and maximum force [MF]) extracted from dynamic foot loading measurements at baseline (t0), 10-month follow-up (t1), and 22-month follow-up (t2). Information on footwear usage was surveyed. Linear mixed modeling was used to test for differences in MLA over time.

RESULTS

The MLA of the children remained stable over time (AI: t0/t1/t2=0.25 [95% confidence interval (CI)=0.24, 0.26]/0.25 [95% CI=0.24, 0.26]/0.25 [95% CI=0.24, 0.26]; P=.95). When the children's sex was considered, the AI of boys decreased (higher arch) with age (0.26 [95% CI=0.24, 0.27]/0.25 [95% CI=0.24, 0.27]/0.25 [95% CI=0.23, 0.27]; P=.02). Boys also displayed a flatter MLA than girls at age 6.9 years (AI: mean difference=0.02 [95% CI=0.01, 0.04]; P=.02). At baseline, children who wore closed-toe shoes displayed the lowest MLA overall (AI: closed-toe shoes/sandals/slippers=0.26 [95% CI=0.24, 0.28]/0.24 [95% CI=0.23, 0.25]/0.25 [95% CI=0.24, 0.26]; P<.01). Children who used slippers at toddlers' age experienced a higher PP (flatter arch) in later childhood than those who wore sandals (mean difference=31.60 kPa [95% CI=1.44, 61.75]; post hoc P=.04).

LIMITATIONS

Information on the type of footwear worn was self-reported and, therefore, may be subjected to recall bias.

CONCLUSIONS

The MLA of children remained stable from 7 to 9 years of age. The child's sex and the type of footwear worn during childhood may influence MLA development.

Toe flexor strength and foot arch height in children

PURPOSE

The aim of this study was to investigate the muscle strength and arch height of the foot in the standing position and the relations between these indices and physical performances involving the lower limbs in children.

METHODS

A total of 301 elementary school children (third grade: n = 158, age = 8.6 ± 0.5 yr; fifth grade: n = 143, age = 10.6 ± 0.5 yr; means ± SD) participated. The maximal isometric toe flexor strength (TFS) in the standing position was measured using a toe flexor dynamometer. Foot arch height was assessed as the distance between the navicular tuberosity of the foot and the floor in the standing position, and foot arch height relative to the foot length was represented by the foot arch index (FAI). For physical performance involving the lower limbs, 50-m sprint, standing broad jump, repeated side step, and rebound jump were measured.

RESULTS

There were no significant correlations between TFS and FAI and between relative TFS (relative TFS = TFS/body mass) and FAI. Relative TFS was significantly correlated with all physical performance tests. No significant correlations among FAI and physical performances were found, except for rebound jump ability in fifth graders. After multiple regression analyses adjusting for gender and body mass, TFS was the only significant correlating factor for all physical performances involving the lower limbs.

CONCLUSIONS

This study showed that TFS was associated with enhancement of some measures of lower limb physical performance in children. These results suggest that foot function should be evaluated with both the muscle strength and arch height of the foot in children.

Effect of Obesity Level on the Longitudinal Arch in 7- to 12-Year-Old Rural and Urban Children

BACKGROUND

We sought to evaluate the influence of obesity level on the medial longitudinal arch (MLA) of the foot in 7- to 12-year-old children.

METHODS

The study group consisted of 925 children (450 girls and 475 boys). All of the children were subjected to podoscopic foot examination and measurement of weight, height, three skinfolds, fat weight, and fat-free body weight.

RESULTS

The most common type of MLA was high-arched foot, which was observed in the left foot of 523 children (56.5%) and in the right foot in 592 children (64%). In almost all of the age groups, high-arched foot was the most common disorder. High-arched foot was more common in girls than in boys, and boys displayed a higher percentage of flatfoot. Also, sex-related differences were more prominent in urban children. There was a strongly positive correlation between obesity level and MLA in the examined group.

CONCLUSIONS

These results suggest that the type of foot arch is influenced by parameters such as age, sex, and obesity level. High-arched foot seemed to be the most frequent pathologic abnormality in the examined group, and flatfoot, which was predominant in boys and obese children, diminished with age. High-arched foot was a more common MLA type than flatfoot regardless of obesity level assessed on the basis of body mass index and sum of three skinfolds.

The relationship between paediatric foot posture and body mass index: do heavier children really have flatter feet?

Background

Several studies have found positive correlation between flatfeet and increased body mass in children. One study, utilizing a differing method of foot posture assessment, found the inverse. The purpose of this study was to further explore the relationship between children’s foot posture and body mass, utilizing the foot posture index in a large study population, as opposed to the footprint based measures of most previous studies.

Methods

Data for both foot posture index (FPI) and body mass index (BMI) for healthy children were acquired from five previous studies. The amalgamated dataset comprised observations for both BMI and FPI-6 in 728 children aged from three to 15 years. Three FPI-6 scores levels defined the range of flatfeet detected: FPI-6 ≥ +6; FPI-6 ≥ +8; FPI-6 ≥ +10. BMI cut-points were used to define overweight for each age group.

Results

In the study population of 728 children, flatfeet (FPI ≥ +6) were found in 290 (40 %) cases and non-flatfeet in 438 (60 %) cases. FPI ≥ +8 yielded flatfeet in 142 (20 %) cases and FPI ≥ +10 yielded flatfeet in 41 (5 %) cases. Whilst 272 (37 %) children were overweight, only 74 (10.1 %) of the overweight children had flatfeet (FPI ≥ +6), which diminished to 36 (4.9 %) at FPI ≥ +8, and 9 (1.2 %) at FPI ≥ +10.

Significant and moderate correlation was found between BMI and age (r = 0.384, p < 0.01). Very weak, but significant, correlation was found between BMI and FPI (r = −0.077, p < 0.05). Significant mean differences between gender and BMI were found (t-test = 2.56, p < 0.05). There was strong correlation between FPI scores on left and right sides (r = 0.899, p < 0.01).

Conclusions

This study found no association between increased body mass and flatfeet in children, a finding in contrast to that repeatedly concluded by many previous studies. Whilst properties of the FPI and BMI are limiting, these findings question the concern about children’s increased body mass as a specific influence on (flatter) foot posture, and also the validity of footprint versus anatomically based foot posture measures.

Automatic Detection of Calcaneal-Fifth Metatarsal Angle Using Radiograph: A Computer-Aided Diagnosis of Flat Foot for Military New Recruits in Taiwan

Flatfoot (pes planus) is one of the most important physical examination items for military new recruits in Taiwan. Currently, the diagnosis of flatfoot is mainly based on radiographic examination of the calcaneal-fifth metatarsal (CA–MT5) angle, also known as the arch angle. However, manual measurement of the arch angle is time-consuming and often inconsistent between different examiners. In this study, seventy male military new recruits were studied. Lateral radiographic images of their right and left feet were obtained, and mutual information (MI) registration was used to automatically calculate the arch angle. Images of two critical bones, the calcaneus and the fifth metatarsal bone, were isolated from the lateral radiographs to form reference images, and were then compared with template images to calculate the arch angle. The result of this computer-calculated arch angle was compared with manual measurement results from two radiologists, which showed that our automatic arch angle measurement method had a high consistency. In addition, this method had a high accuracy of 97% and 96% as compared with the measurements of radiologists A and B, respectively. The findings indicated that our MI registration measurement method cannot only accurately measure the CA–MT5 angle, but also saves time and reduces human error. This method can increase the consistency of arch angle measurement and has potential clinical application for the diagnosis of flatfoot.

The association of foot structure and footwear fit with disability in children and adolescents with Down syndrome

Background

Foot deformity, flat feet, and the use of ill-fitting footwear are common in children and adolescents with Down syndrome (DS). The aim of this study was to determine whether these observations are associated with foot-specific disability in this group.

Methods

A cross-sectional study design. Foot structure (foot posture determined using the Arch Index, presence of hallux valgus and lesser toe deformities) and footwear fit (determined by length and width percentage differences between the participant’s foot and footwear) were assessed in 50 participants with DS (22 females, 28 males) aged five to 18 with a mean (SD) age of 10.6 (3.9) years. Foot-specific disability was determined using the parent-reported Oxford Ankle Foot Questionnaire for Children (OxAFQ-C). Associations between foot structure and footwear fit with the four domains (Physical, School and play, Emotional and Footwear) of the OxAFQ-C were determined using multivariate regression modelling.

Results

The mean (SD) Arch Index was 0.29 (0.08), and the prevalence of flat feet, hallux valgus and lesser toe deformities was 76%, 10% and 12% respectively. Few participants wore footwear that was too short (10%), but the use of footwear that was too narrow was common (58%). The presence of hallux valgus was significantly associated with increased disability for the OxAFQ-C School and play domain scores. The use of narrow-fitting footwear was significantly associated with increased levels of disability for the OxAFQ-C Physical, School and play, and Emotional domains. However, these variables only explained between 10% to 14% of the variance in the OxAFQ-C domain scores. There were no significant associations between foot structure and footwear fit with the OxAFQ-C Footwear domain scores.

Conclusions

Flatter feet and lesser toe deformities are not associated with foot-specific disability in children and adolescents with DS. Hallux valgus is associated with foot-specific disability during school and play activities. Ill-fitting footwear (too narrow) is common and is associated with foot-specific disability. Further research is required to identify if the relationship between narrow-fitting footwear and foot-specific disability is causal, and to identify other factors associated with foot-specific disability in children and adolescents with DS.

Standard growth of the foot arch in childhood and adolescence--derived from the measurement results of 10,155 children

BACKGROUND

The definition of flatfoot remains analytically vague. Toward the purpose of establishing the standard values of the foot length and arch height in childhood and adolescence, large-scale measurement and investigation of the foot arch were conducted using a three-dimensional foot-measuring device.

METHODS

Measurements of foot structure were performed on 5311 boys and 4844 girls, for a total of 20,310 ft. of 10,155 children aged from 6 to 18 years during the 2006-2008 year period. The foot length (FL) and the navicular height (NH) were measured, and the arch height ratio (AHR (%)=NH×100/FL) was calculated.

RESULTS

The FL in boys showed an extension from the age of 6 to 14 and nearly reached a plateau at 14 years old. In girls, the extension was observed from the age of 6 to 13, and the FL came to a plateau at 13 years old. The NH in boys increased from the age of 6 to 13. In girls, the NH increased from the age of 8 to 13. The AHR, presented a normal distribution, and no differences were observed in the distribution for all ages in boys and girls. In boys, the AHR was almost flat until 11 years old, but elevated in the 11-13 year age period. In girls, the AHR was almost flat until 10 years old, but elevated in the 10-12 year age period.

CONCLUSIONS

We are certain that the data demonstrating the normal growth of the foot contribute to the diagnosis and treatment of the failure of the foot to thrive.

Footwear suitability in Turkish preschool-aged children

BACKGROUND

Unsuitable footwear worn in childhood may cause some foot problems by interfering normal development of foot.

OBJECTIVES

To compare footwear suitability rate of indoor and outdoor footwear at all points in preschool children and investigate factors which could affect footwear suitability.

STUDY DESIGN

A cross-sectional survey study.

METHODS

A total of 1000 healthy preschool children (4-6 years old) participated in this study. Indoor and outdoor footwear of children were evaluated through Turkish version of Footwear Assessment Score. Effect of factors like age, sex, number of siblings, educational and occupational situation of parents, and behavior of school management about selecting footwear was investigated.

RESULTS

Children got better footwear score for outdoor than indoor ones (p < 0.001). Boys got statistically better footwear score for both indoor and outdoor ones than girls (p < 0.001). Also significant difference in footwear score was found in favor of children who were going to schools that gave guidance about selecting footwear for both indoor and outdoor in comparison to children going to other schools (p < 0.001).

CONCLUSIONS

For healthy foot development, parents need an education about suitable footwear for their children. Performing education programs and investigation of their effect with comprehensive follow-up studies in future is essential.

CLINICAL RELEVANCE

This study reflects footwear habits of Turkish preschool children and factors affecting this issue. Results may give way to education programs about suitable footwear worn in childhood for healthy foot development.

Maximum toe flexor muscle strength and quantitative analysis of human plantar intrinsic and extrinsic muscles by a magnetic resonance imaging technique

Background

The aims of this study were to investigate the relationships between the maximum isometric toe flexor muscle strength (TFS) and cross-sectional area (CSA) of the plantar intrinsic and extrinsic muscles and to identify the major determinant of maximum TFS among CSA of the plantar intrinsic and extrinsic muscles.

Methods

Twenty six young healthy participants (14 men, 12 women; age, 20.4 ± 1.6 years) volunteered for the study. TFS was measured by a specific designed dynamometer, and CSA of plantar intrinsic and extrinsic muscles were measured using magnetic resonance imaging (MRI). To measure TFS, seated participants optimally gripped the bar with their toes and exerted maximum force on the dynamometer. For each participant, the highest force produced among three trials was used for further analysis. To measure CSA_, serial T1-weighted images were acquired.

Results

TFS was significantly correlated with CSA of the plantar intrinsic and extrinsic muscles. Stepwise multiple linear regression analyses identified that the major determinant of TFS was CSA of medial parts of plantar intrinsic muscles (flexor hallucis brevis, flexor digitorum brevis, quadratus plantae, lumbricals and abductor hallucis). There was no significant difference between men and women in TFS/CSA.

Conclusions

CSA of the plantar intrinsic and extrinsic muscles is one of important factors for determining the maximum TFS in humans.

Association between foot type and lower extremity injuries: systematic literature review with meta-analysis

STUDY DESIGN

Systematic literature review with meta-analysis.

OBJECTIVES

To investigate the association between nonneutral foot types (high arch and flatfoot) and lower extremity and low back injuries, and to identify the most appropriate methods to use for foot classification.

METHODS

A search of 5 electronic databases (PubMed, Embase, CINAHL, SPORTDiscus, and ProQuest Dissertations and Theses), Google Scholar, and the reference lists of included studies was conducted to identify relevant articles. The review included comparative cross-sectional, case-control, and prospective studies that reported qualitative/quantitative associations between foot types and lower extremity and back injuries. Quality of the selected studies was evaluated, and data synthesis for the level of association between foot types and injuries was conducted. A random-effects model was used to pool odds ratio (OR) and standardized mean difference (SMD) results for meta-analysis.

RESULTS

Twenty-nine studies were included for meta-analysis. A significant association between nonneutral foot types and lower extremity injuries was determined (OR = 1.23; 95% confidence interval [CI]: 1.11, 1.37; P<.001). Foot posture index (OR = 2.58; 95% CI: 1.33, 5.02; P<.01) and visual/physical examination (OR = 1.17; 95% CI: 1.06, 1.28; P<.01) were 2 assessment methods using distinct foot-type categories that showed a significant association with lower extremity injuries. For foot-assessment methods using a continuous scale, measurements of lateral calcaneal pitch angle (SMD, 1.92; 95% CI: 1.44, 2.39; P<.00001), lateral talocalcaneal angle (SMD, 1.36; 95% CI: 0.93, 1.80; P<.00001), and navicular height (SMD, 0.34; 95% CI: 0.16, 0.52; P<.001) showed significant effect sizes in identifying high-arch foot, whereas the navicular drop test (SMD, 0.45; 95% CI: 0.03, 0.87; P<.05) and relaxed calcaneal stance position (SMD, 0.49; 95% CI: 0.01, 0.97; P<.05) displayed significant effect sizes in identifying flatfoot. Subgroup analyses revealed no significant associations for children with flatfoot, cross-sectional studies, or prospective studies on high arch.

CONCLUSIONS

High-arch and flatfoot foot types are associated with lower extremity injuries, but the strength of this relationship is low. Although the foot posture index and visual/physical examination showed significance, they are qualitative measures. Radiographic and navicular height measurements can delineate high-arch foot effectively, with only anthropometric measures accurately classifying flatfoot.

LEVEL OF EVIDENCE

Prognosis, level 2a.

Reliability of footprint geometric and plantar loading measurements in children using the Emed(®) M system

This study investigated the between-day reliability of footprint geometric and plantar loading measurements on children utilising the Emed(®) M pressure measurement device. Bilateral footprints (static and dynamic) and foot loading measurements using the two-step gait method were collected on 21 children two days apart (age = 9.9 ± 1.8 years; mass = 34.6 ± 8.9 kg; height = 1.38 ± 0.12 m). Static and dynamic footprint geometric (lengths, widths and angles) and dynamic loading (pressures, forces, contact areas and contact time) parameters were compared. Intraclass correlation coefficients of static geometric parameters were varied (0.19-0.96), while superior results were achieved with dynamic geometric (0.66-0.98) and loading variables (0.52-0.94), with the exception of left contact time (0.37). Standard error of measurement recorded small absolute disparity for all geometric (length = 0.1-0.3 cm; arch index = 0.00-0.01; subarch angle = 0.6-6.2°; left/right foot progression angle = 0.5°/0.7°) and loading (peak pressure = 2.3-16.2 kPa; maximum force = 0.3-3.0%; total contact area = 0.28-0.49 cm(2); % contact area = 0.1-0.6%; contact time = 32-79 ms) variables. Coefficient of variation displayed widest spread for static geometry (1.1-27.6%) followed by dynamic geometry (0.8-22.5%) and smallest spread for loading (1.3-16.8%) parameters. Limits of agreement (95%) were narrower in dynamic than static geometric parameters. Overall, the reliability of most dynamic geometric and loading parameters was good and excellent. Static electronic footprint measurements on children are not recommended due to their light body mass which results in incomplete footprints.

Three-dimensional measurement of foot arch in preschool children

Background

The prevalence of flexible flatfoot is high among preschool-aged children, but the effects of treatment are inconclusive due to the unclear definitions of normal flatfoot. To date, a universally accepted evaluation method of the foot arch in children has not been completely established. Our aims of this study were to establish a new method to evaluate the foot arch from a three dimensional perspective and to investigate the flexibility of the foot arch among children aged from two to six.

Methods

A total of 44 children aged from two to six years of age were put into five age groups in this study. The navicular height was measured with one leg standing, and both feet were scanned separately in both sitting and one leg standing positions to compute the foot arch volume. The arch volume index, which represents the ratio of the difference in volume between sitting and one leg standing positions to the volume when sitting was calculated to demonstrate the flexibility of the foot arch. The differences of measured parameters between each aged group were analyzed by one-way ANOVA.

Results

The arch volumes when sitting and standing were highly correlated with the navicular height. The navicular height ranged from 15.75 to 27 mm, the arch volume when sitting ranged from 6,223 to 11,630 mm³, and the arch volume when standing from 3,111 to 7,848 mm³ from two to six years of age. The arch volume index showed a declining trend as age increased.

Conclusion

This study is the first to describe the foot arch with volume perspective in preschool-aged children. The foot arch volume was highly correlated with the navicular height. Research results show both navicular height index and arch volume index gradually increase with age from two to six. At the same time the arch also becomes rigid with age from two to six. These results could be applied for clinical evaluation of the foot arch and post-treatment evaluation.

Dynamic footprint measurement collection technique and intrarater reliability: ink mat, paper pedography, and electronic pedography

BACKGROUND

Identifying the variability of footprint measurement collection techniques and the reliability of footprint measurements would assist with appropriate clinical foot posture appraisal. We sought to identify relationships between these measures in a healthy population.

METHODS

On 30 healthy participants, midgait dynamic footprint measurements were collected using an ink mat, paper pedography, and electronic pedography. The footprints were then digitized, and the following footprint indices were calculated with photo digital planimetry software: footprint index, arch index, truncated arch index, Chippaux-Smirak Index, and Staheli Index. Differences between techniques were identified with repeated-measures analysis of variance with post hoc test of Scheffe. In addition, to assess practical similarities between the different methods, intraclass correlation coefficients (ICCs) were calculated. To assess intrarater reliability, footprint indices were calculated twice on 10 randomly selected ink mat footprint measurements, and the ICC was calculated.

RESULTS

Dynamic footprint measurements collected with an ink mat significantly differed from those collected with paper pedography (ICC, 0.85-0.96) and electronic pedography (ICC, 0.29-0.79), regardless of the practical similarities noted with ICC values (P = .00). Intrarater reliability for dynamic ink mat footprint measurements was high for the footprint index, arch index, truncated arch index, Chippaux-Smirak Index, and Staheli Index (ICC, 0.74-0.99).

CONCLUSIONS

Footprint measurements collected with various techniques demonstrate differences. Interchangeable use of exact values without adjustment is not advised. Intrarater reliability of a single method (ink mat) was found to be high.

Footprint-based estimates of arch structure are confounded by body composition in adults

Previous research employing indirect measures of arch structure, such as those derived from footprints, have indicated that obesity results in a "flatter" foot type. In the absence of radiographic measures, however, definitive conclusions regarding the osseous alignment of the foot cannot be made. We determined the effect of body mass index (BMI) on radiographic and footprint-based measures of arch structure. The research was a cross-sectional study in which radiographic and footprint-based measures of foot structure were made in 30 subjects (10 males, 20 female) in addition to standard anthropometric measures of height, weight, and BMI. Multiple (univariate) regression analysis demonstrated that both BMI (β = 0.39, t(26) = 2.12, p = 0.04) and radiographic arch alignment (β = 0.51, t(26) = 3.32, p < 0.01) were significant predictors of footprint-based measures of arch height after controlling for all variables in the model (R(2) = 0.59, F(3,26) = 12.3, p < 0.01). In contrast, radiographic arch alignment was not significantly associated with BMI (β = -0.03, t(26) = -0.13, p = 0.89) when Arch Index and age were held constant (R(2) = 0.52, F(3,26) = 9.3, p < 0.01). Adult obesity does not influence osseous alignment of the medial longitudinal arch, but selectively distorts footprint-based measures of arch structure. Footprint-based measures of arch structure should be interpreted with caution when comparing groups of varying body composition.

Screening for foot problems in children: is this practice justifiable?

Podiatry screening of children is a common practice, which occurs largely without adequate data to support the need for such activity. Such programs may be either formalised, or more ad hoc in nature, depending upon the use of guidelines or existing models. Although often not used, the well-established criteria for assessing the merits of screening programs can greatly increase the understanding as to whether such practices are actually worthwhile. This review examines the purpose of community health screening in the Australian context, as occurs for tuberculosis, breast, cervical and prostate cancers, and then examines podiatry screening practices for children with reference to the criteria of the World Health Organisation (WHO). Topically, the issue of paediatric foot posture forms the focus of this review, as it presents with great frequency to a range of clinicians. Comparison is made with developmental dysplasia of the hip, in which instance the WHO criteria are well met. Considering that the burden of the condition being screened for must be demonstrable, and that early identification must be found to be beneficial, in order to justify a screening program, there is no sound support for either continuing or establishing podiatry screenings for children.

The effects of low arched feet on lower limb gait kinematics in children

BACKGROUND

The effects of foot posture on the dynamic function of the lower limb during gait remains relatively unknown.

OBJECTIVES

The purpose of this study was to investigate lower limb kinematics between the normal and low arched foot during the gait cycle, particularly in the transverse plane.

METHOD

Twenty-four children, twelve with normal and twelve with low arched feet, aged 11-12 years underwent a lower limb three dimensional gait analysis. Temporo-spatial parameters and patterns and ranges of motion of kinematic data were examined for the pelvis, hip, knee and ankle throughout the gait cycle.

RESULTS

Overall, there were very few differences found in the kinematics of the lower limbs between the normal and low arched group. Increased external hip rotation (6-7°) in the low arched group was the only bilateral significant difference (p<0.05) between the two foot groups. No significant differences existed in any temporo-spatial parameters between the two groups.

CONCLUSIONS

The increased external hip rotation and greater external foot progression angle in the low arched foot highlights the need to examine gait comprehensively to establish cause or effect of these differences observed and hence determine appropriate treatment.

The influence of body weight, body mass index and gender on plantar pressures: results of a cross-sectional study of healthy children's feet

The purpose of this study was to determine if plantar pressure data in 4-7 year old children with normal development: (1) required normalising by body mass and/or body mass index and (2) should be separated or pooled for boys and girls. The outcome will guide the management of plantar pressure data in future work investigating changes in plantar pressure distribution with increasing age. In a cross-sectional design, 98 British children (45 girls) with no orthopaedic, neurological or developmental disorders provided plantar pressure measurements during walking. Peak plantar pressure and plantar pressure time integrals were obtained from nine areas under the foot: calcaneus, medial and lateral midfoot, each of the five metatarsals and the hallux. Body weight and body mass index demonstrated low and weak degrees of association (r≤0.48, p<0.05) with plantar pressure data. Boys and girls showed no difference in plantar pressures (p<0.05). Plantar pressure data for 4-7 year olds does not require normalisation with body mass or body mass index, and can be pooled for boys and girls.