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

Flatfoot Reconstruction for Painful Pediatric Idiopathic Flexible Flatfoot: Prospective Study Demonstrates Improved Alignment, Function, and Patient-reported Outcomes

BACKGROUND

This prospective study was undertaken to report outcomes following reconstructive surgery for patients with painful pediatric idiopathic flexible flatfoot.

METHODS

Twenty-five patients with pediatric idiopathic flexible flatfoot were evaluated pre- and post flatfoot reconstruction with lateral column lengthening (LCL). All patients had lengthening of the Achilles or gastrocnemius, while 13 patients had medial side soft tissue (MSST) procedures, 7 underwent medial cuneiform plantarflexion osteotomy (MCPO), and 5 had medializing calcaneal osteotomy. Measures of static foot alignment-both radiographic parameters and clinical arch height indices-were compared, as were measures of dynamic foot alignment and loading, including arch height flexibility and pedobarography. Preoperative and postoperative patient-reported outcome (PRO) scores were compared between those treated with or without MSST procedures.

RESULTS

The median subject age was 13.8 years (range: 10.3 to 16.5) at the time of surgery. All radiographic parameters improved with surgery ( P <0.001). The mean sitting arch height index showed a modest increase after surgery ( P =0.023). Arch height flexibility was similar after surgery. The mean center-of-pressure excursion index increased from 14.1% to 24.0% ( P <0.001), and the mean first metatarsal head (MH) peak pressure dropped ( P <0.001), while the mean fifth MH peak pressure increased ( P =0.018). The ratio of peak pressure in the fifth MH to peak pressure in the second MH increased ( P =0.010). The ratio of peak pressure in the first MH to peak pressure in the second MH decreased when an MCPO was not used ( P <0.002), but it remained stable when an MCPO was included. Mean scores in all PRO domains improved ( P <0.001). Patients treated without MSST procedures showed no difference in PROMIS Pain Interference scores compared to those without MSST procedures.

CONCLUSIONS

Flatfoot reconstruction surgery using an LCL with plantarflexor lengthening results in improved PROs. LCL changes but does not normalize the distribution of MH pressure loading. The addition of an MCPO can prevent a significant reduction in load-sharing by the first MH.

A deep learning method for foot-type classification using plantar pressure images

Background: Flat foot deformity is a prevalent and challenging condition often leading to various clinical complications. Accurate identification of abnormal foot types is essential for appropriate interventions. Method: A dataset consisting of 1573 plantar pressure images from 125 individuals was collected. The performance of the You Only Look Once v5 (YOLO-v5) model, improved YOLO-v5 model, and multi-label classification model was evaluated for foot type identification using the collected images. A new dataset was also collected to verify and compare the models. Results: The multi-label classification algorithm based on ResNet-50 outperformed other algorithms. The improved YOLO-v5 model with Squeeze-and-Excitation (SE), the improved YOLO-v5 model with Convolutional Block Attention Module (CBAM), and the multilabel classification model based on ResNet-50 achieved an accuracy of 0.652, 0.717, and 0.826, respectively, which is significantly higher than those obtained using the ordinary plantar-pressure system and the standard YOLO-v5 model. Conclusion: These results indicate that the proposed DL-based multilabel classification model based on ResNet-50 is superior in flat foot type detection and can be used to evaluate the clinical rehabilitation status of patients with abnormal foot types and various foot pathologies when more data on patients with various diseases are available for training.

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.

Interobserver Reliability in the Radiological Evaluation of Flatfoot (Pes Planus) Deformity: A Cross-Sectional Study

This study was planned for analyzing the interobserver reliability on the diagnosis of flatfoot. This study aims to evaluate the interobserver reliability of the digital radiography of flatfoot patients. Eight parameters were used in digital x-rays within the as statistically in 2 groups. Study group includes 34 patients. Two groups were formed four medical specialists as 2 orthopedists and 2 radiologists. Two orthopedists made measurements on x-ray viewing as calcaneal pitch (CP) as CP floor, calcaneus-1 metatarsal angle, calcaneus-5 metatarsal angle; longitudinal arch angles (LAAs) as medial and lateral LAAs, Tomeno-Meary angle (TMA), anteroposterior and lateral CYMA line. The intraclass correlation coefficient (ICC) analysis was performed. Fleiss Kappa and Kappa was used to investigate the reliability of qualitative data between 2 observers. ICCs were in high levels for CP floor, calcaneus-1 metatarsal angle, calcaneus-5 metatarsal angle. ICCs of TMA was in high levels, also. ICCs of LAA-medial and LAA-lateral were not in high levels as other measurements. In the CYMA line (anteroposterior and lateral) Kappa was 0.140 for right feet in the quadruple group (p = .045; .458; and .314). Kappa was 0.197 for left feet in the quadruple group (p = .005; .146; .377). The ICCs was excellent for CP angles and TMA in all groups. LAAs as medial and lateral longitudinal arch angle had not high ICC's. CYMA line had significant p values in the quadruple group. But not in orthopedists and radiologists.

Risk Factors of Flatfoot in Children: A Systematic Review and Meta-Analysis

Background: This study aimed to explore the risk factors for flatfoot in children and adolescents to provide a reference basis for studying foot growth and development in children and adolescents. Methods: We examined the cross-sectional research literature regarding flatfoot in children and adolescents published in the past 20 years, from 2001 to 2021, in four electronic databases: PubMed, Web of Science, EBSCO, and Cochrane Library. Two researchers independently searched the literature according to the inclusion and exclusion criteria and evaluated the literature quality of the selected research; from this, a total of 20 articles were included in our review. After the relevant data were extracted, the data were reviewed using Manager 5.4 software (The Cochrane Collaboration, Copenhagen, Denmark), and the detection rate and risk factors for flatfoot in children were analyzed. Results: In total, 3602 children with flatfoot from 15 studies were included in the analysis. The meta-analysis results showed that being male (OR = 1.33, 95% CI: 1.09, 1.62, p = 0.005), being aged <9 years (age <6, OR = 3.11, 95% CI: 2.47, 3.90, p < 0.001; age 6−9 years, OR = 0.54, 95% CI: 0.41, 0.70, p < 0.001), joint relaxation (OR = 4.82, 95% CI: 1.19, 19.41, p = 0.03), wearing sports shoes (OR = 2.97, 95% CI: 1.46, 6.03, p = 0.003), being a child living in an urban environment (OR = 2.10, 95% CI: 1.66, 2.64, p < 0.001) and doing less exercise (OR = 0.25, 95% CI: 0.08, 0.80, p = 0.02) were risk factors for the detection of flatfoot. Conclusion: In summary, the detection rate of flatfoot in children in the past 20 years was found to be 25% through a meta-analysis. Among the children included, boys were more prone to flatfoot than girls, and the proportion of flatfoot decreased with age.

Validity and Diagnostic Accuracy of the Clarke's Angle in Determining Pediatric Flexible Flatfoot Using Radiographic Findings as a Criterion Standard Measure: A Cross-sectional Study

BACKGROUND

Clinical diagnosis of pediatric flexible flatfoot is still a challenging issue for health-care professionals. Clarke's angle (CA) is frequently used clinically for assessing foot posture; however, there is still debate about its validity and diagnostic accuracy in evaluation of static foot posture especially in the pediatric population, with some previous studies supporting and others refuting its validity. The present study aimed to investigate the validity and diagnostic accuracy of the CA using radiographic findings as a criterion standard measure to determine flexible flatfoot between ages 6 and 18 years.

METHODS

A cross-sectional study of 612 participants (1224 feet) with flexible flatfoot aged 6 to 18 years (mean ± SD age, 12.36 ± 3.39 years) was recruited. The clinical measure results were compared with the criterion standard radiographic measures and displayed on the receiver operating characteristic curve, and the area under the curve was computed. Intrarater reliability, sensitivity, specificity, predictive values, and likelihood ratios were calculated for the CA. A Fagan nomogram was used to detect post-test probability.

RESULTS

The CA demonstrated higher intrarater reliability (intraclass correlation coefficient = 0.997), sensitivity (98.4%), specificity (98.8), positive predictive value (97.3), negative predictive value (99.3), positive likelihood ratio (84), and negative likelihood ratio (0.02). The area under the curve was 0.98. The positive likelihood ratio yielded a post-test probability of 97%, and the negative likelihood ratio yielded a post-test probability of 0.02.

CONCLUSIONS

The CA is a valid measure with high diagnostic accuracy in the diagnosis of flexible flatfoot between ages 6 and 18 years.

Comparing Validity and Diagnostic Accuracy of Clarke's Angle and Foot Posture Index-6 to Determine Flexible Flatfoot in Adolescents: A Cross-Sectional Investigation

OBJECTIVE

Clinically, the foot posture index-6 (FPI-6) and Clarke's angle (CA) are widely utilized to assess static foot posture; however, due to scarcity of scientific evidence, clinicians continue to debate the validity and diagnostic accuracy of these measures in children and adolescents. This study aimed to evaluate and compare the validity and diagnostic accuracy of the FPI-6 and CA in determining adolescents' flexible flatfoot between ages of 12 and 18 years, considering radiographic investigation as a reference standard measure.

DESIGN

Cross-sectional study.

SETTING

Governmental hospitals.

PARTICIPANTS AND METHODS

A sample of 460 people (920 feet) with flexible flatfoot between the ages of 12 and 18 (15.23 ± 0.84 years) was enrolled in the study. The findings of the investigated measures were compared to the reference standard radiographic measure and plotted on the receiver operating characteristic (ROC) curve. The area under the ROC curve (AUC) was determined as a measure of FPI-6 and CA diagnostic accuracy. Intra-rater reliability, sensitivity, specificity, predictive values, and likelihood ratios of FPI-6 and CA were calculated and compared. The post-test probability of flatfoot was determined using the Fagan nomogram.

RESULTS

CA had a substantially higher intra-rater reliability (ICC=0.99) than the FPI-6 (ICC=0.96), with p-value of 0.001. CA has greater sensitivity (98%) than FPI-6, as well as a superior specificity (99%), positive predictive value (98%), negative predictive value (98.9%), positive likelihood ratio (97), and a lower negative likelihood ratio (0.02). CA had such an area under ROC curve of 0.98 with a 95% confidence interval of 0.95-1.00, while FPI-6 had an area under ROC curve of 0.80 with a 95% confidence interval of (0.77-0.85).

CONCLUSION

FPI-6 and Clarke's angle are both valid and diagnostically accurate clinical tests for flatfoot detection, with Clarke's angle outperforming FPI-6 in adolescents aged 12 to 18 years with a normal BMI.

Comparison of the degree of pes planovalgus and muscle mass of the ankle joint and foot muscles between children with Down syndrome and children with typical development

We aimed to compare the degree of pes planovalgus and muscle mass of the ankle joint and foot muscles between children with Down syndrome (DS) and children with typical development (TD). We also examined the association of the degree of pes planovalgus with muscle mass of the ankle joint and foot muscles in children with DS and children with TD. The subjects were 24 children with TD (control [CTR] group) and 23 children with DS (DS group). To assess pes planovalgus, the Arch Height Index (AHI) in the standing position was measured. Muscle thickness of the ankle joint and foot muscles was measured using an ultrasound imaging device. The AHI and thickness of the soleus and tibialis posterior muscles were significantly lower in the DS group than those in the CTR group. The thickness of the flexor digitorum longus muscle was significantly greater in the DS group than that in the CTR group. Stepwise regression analysis revealed that the thickness of the flexor digitorum longus muscle was a significant and independent factor of the AHI in children comprising the CTR and DS groups. The thickness of the flexor digitorum longus muscle increased with decreasing AHI. The results of this study suggest that the AHI and muscle mass of the soleus and tibialis posterior muscles decrease, while muscle mass of the flexor digitorum longus muscle increases in children with DS. The results also indicate that decreased AHI is associated with increased muscle mass of the flexor digitorum longus muscle in children.

A Narrative Review on the Tests Used in Biomechanical Functional Assessment of the Foot and Leg: Diagnostic Tests of Deformities and Compensations

BACKGROUND

To date, scientific literature has not as yet come up with any review showing the diagnostic tests used for functional assessment of the foot and leg.

METHODS

A literature review was conducted of electronic databases (MEDLINE, PEDro, DOAJ, BioMed Central, PLOS, and Centre for Reviews and Dissemination at the University of York) up to December 8, 2018. The biomechanical tests, which have adequate supportive literature, were divided into qualitative tests that provide a dichotomy/trichotomy-type answer to clinical diagnostic questions; semiquantitative tests that provide numerical data to clinical diagnostic questions; and quantitative tests that record continuous numerical data (in analogue or digital form).

RESULTS

These tests produce a useful functional evaluation model of the foot and leg for different purposes: evaluation of lower limb deficits or abnormalities in healthy patients and in athletes (in sports or other physical activities); assessment of tissue stress syndromes caused by pathomechanics; evaluation of lower limb deficits or abnormalities in rheumatic disease and diabetic foot patients; and to determine the appropriate functional or semifunctional foot orthotic therapy and therapeutic path used in gait rehabilitation.

CONCLUSIONS

Many of these tests have adequate diagnostic reliability and reproducibility and therefore can be considered diagnostic. Few of these are validated, and some have initiated the validation process by determining their sensitivity and specificity. The widespread use of these tools in clinical practice (diagnosis of function) lacks scientific evidence and in-depth analysis of their limitations.

Validity and diagnostic accuracy of foot posture Index-6 using radiographic findings as the gold standard to determine paediatric flexible flatfoot between ages of 6-18 years: A cross-sectional study

BACKGROUND

Diagnosis of flexible flatfoot is usually based upon radiographic or clinical measures. Radiographic measures pose a potential risk of radiation exposure especially in Paediatric population. Clinicians need a valid, accurate, easily used, noninvasive and cost effective measure to evaluate static foot posture clinically. Although, foot posture index-6 (FPI-6) are commonly used in clinical practice, its validity and diagnostic accuracy in evaluation of paediatric flexible flatfoot have not been fully proven yet.

OBJECTIVES

To investigate validity and diagnostic accuracy of FPI-6 to determine Paediatric flexible flatfoot between ages of 6-18 years using radiographic findings as the gold standard measure.

STUDY DESIGN

Cross-sectional study.

METHODS

A cross-sectional study conducted on 612 participants (1224 feet) with flexible flatfoot aged 6-18 years (mean age ± standard deviation of 12.36 ± 3.39 years). The results of FPI-6 were compared to the gold standard radiographic measures and displayed on the receiver operating characteristic curve. Intra-rater reliability, sensitivity, specificity, predictive values and likelihood ratios were calculated. Posttest probability was calculated from Fagan nomogram.

RESULTS

FPI-6 demonstrate high intra-rater reliability (ICC = 0.96) with p value < 0.001. FPI-6 showed a sensitivity of 83.7%, a specificity of 80.4, a positive predictive value of 64.7, a negative predictive value of 92, a positive likelihood ratio of 4.62 and a negative likelihood ratio of 0.20. FPI-6 shows moderate diagnostic accuracy [AUC = 0.82; 95%CI (0.78-0.85)].

CONCLUSION

FPI-6 is valid with moderate diagnostic accuracy to determine paediatric flexible flatfoot between ages of 6-18 years.

International normative data for paediatric foot posture assessment: a cross-sectional investigation

OBJECTIVES

The foot posture index (FPI) is an observational tool designed to measure the position of the foot. The objective of this study was to establish international reference data for foot posture across childhood, and influence of body mass index (BMI) on paediatric foot posture.

DESIGN

Cross-sectional study.

SETTING AND PARTICIPANTS

The dataset comprised 3217 healthy children, aged from 3 to 15 years. Contributing data were acquired from Spain, UK and Australia.

INTERVENTIONS

Foot posture was described by means and z-score of the FPI and the height and weight of each subject was measured and the BMI was calculated.

RESULTS

The foot posture of 3217 children were reviewed. A pronated (FPI ≥+6) foot posture was found in 960 (29.8%) children, a normal (FPI 0 to +6) foot posture in 1776 (55.2%) and a highly pronated (FPI +10) foot posture was found in 127 children (3.9%) (range -4 to +12 FPI). Less than 11% were found to have a supinated foot type (n=354). Approximately 20% of children were overweight/obese, but correlation between BMI and FPI was weak and inverse (r=-0.066, p<0.01), refuting the relationship between increased body mass and flatfeet.

CONCLUSIONS

This study confirms that the 'flat' or pronated foot is the common foot posture of childhood, with FPI score of +4 (3) the average finding. Trend indicated a less flatfoot with age, although non-linear. A wide normal range of foot posture across childhood is confirmed.

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.