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Gepubliceerd in: Journal of Foot and Ankle Research 1/2018

Open Access 01-12-2018 | Review

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

Auteurs: Helen A. Banwell, Maisie E. Paris, Shylie Mackintosh, Cylie M. Williams

Gepubliceerd in: Journal of Foot and Ankle Research | Uitgave 1/2018

Abstract

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.
Opmerkingen

Electronic supplementary material

The online version of this article (https://​doi.​org/​10.​1186/​s13047-018-0264-3) contains supplementary material, which is available to authorized users.
Afkortingen
AP
anteroposterior
FGP
foot ground pressure
FPI-6
foot posture index – 6 item
GALLOP
Gait and Lower Limb observations of Paediatrics proforma
ICCs
Intraclass Correlation Coefficient
LAC
longitudinal axis of calcaneus
LAF
longitudinal axis of foot
MLA
medial longitudinal arch
NA
not available
NR
not reported

Background

Flexible flat foot (also known as pes planus or planovalgus) in children, when there is the appearance of a lowered medial longitudinal arch, with or without rearfoot eversion [1] is one of the most frequently reported reasons to seek orthopaedic opinion [2]. Yet, in typically developing children, normative data indicates ‘flat’ is normal for children up to eight years of age [3], due to age appropriate osseous and ligamentous laxity, increased adipose tissue and immature neuromuscular control [4, 5]. Although variable, the ‘flatness’ of this foot posture reduces over the first decade of life [3, 69]. However, some children with a flexible flat foot posture report lower limb pain [10] and have demonstrated reduced lower limb function [11]. Furthermore, adults with flexible flat feet report significantly increased levels of back and lower limb pain [12] and reduced quality of life [13]. The challenge for health professionals is in identifying when a child’s foot is, or isn’t, in keeping with developmental expectations, particularly in relation to foot posture and/or function; in order to reassure, monitor or intervene accordingly [14, 15]. Therefore, the measure used to indicate where a foot posture is outside of the expected flatness in children (i.e. the diagnoses of flat foot) needs to be valid, reliable and appropriate for developing foot posture typically observed.
Flat foot is diagnosed through a variety of measures, including plain film radiographs (e.g. x-ray), static foot posture measures and footprint analysis [16]. Plain film radiographs are considered the reference standard to determine flat foot magnitude; however, this method is costly, involves radiation risk, and is not routinely used in clinical practice [17]. Plain film radiographs, static postures or footprint methods allow flat foot description by analysing different angles or measures and, in many cases, comparing these to known population norms. The prevalence of paediatric flat foot has been reported as low as 0.6% and as high as 77.9% (age range 5 to 14 years and 11 months to 5 years respectively), [18, 19]. Whilst an explanation of this broad variation may be due to the changing foot posture as the child develops, there is concern that the measures of flat foot may not differentiate between what is an expected level of ‘flatness’ in children and abnormal presentations [3]. To the best of the authors knowledge, there is no comprehensive review of the psychometric properties of flat foot measures as they apply to the paediatric population [16].
The two core elements of psychometric properties are reliability and validity [20]. Reliability relates to the inherent variability of a foot posture measure and the error that is attributable to the rater and the tool used, expressed as the stability of the data when measured by: one observer over two or more occasions (i.e. intra-rater reliability); or two or more observers (inter-rater reliability), [21]. Validity relates to the extent to which a tool measures what it is intended to measure [21]. Validity of a foot posture measure can be expressed in several ways. For example, criterion-related validity would be the ability of one measure of flat foot to predict results of another measure of flat foot that is assumed to be valid, such as comparing a foot print indices to a plain film radiograph as the reference standard [20]. Or construct validity, which in broad terms determines if the measure has enough ‘sensitivity’ to detect when the condition exists (e.g. a measure with high sensitivity has a low level of false-positive diagnoses), and ‘specificity’ to detect when the condition does not exist (e.g. a measure with high specificity has a low level of false-negative diagnoses) [22]. To be confident that a diagnosis of flat foot is correct, the measure used needs to be both valid and reliable for the population to which it’s applied.
The primary aim of this systematic review was to investigate how paediatric foot posture is measured and how paediatric flat foot posture is defined. The secondary aim is to identify the psychometric properties of the foot posture measures used to determine if these measures are valid and reliable for this population.

Methodology

Protocol and registration

The systematic review was guided by the PRISMA protocol [23]. The registered protocol is listed on PROSPERO, registration number: CRD42016033237.
The following databases were searched from inception to Jan 2017: MEDLINE [Ovid], CINAHL, EMBASE, The Cochrane Library, AMED, SportDiscus, PsycINFO, and Web of Science. The search terms are outlined within Table 1.
Table 1
Search terms for systematic review of the literature on flexible flat foot in paediatrics
Search Terms
Foot/ OR Feet
AND
Child/ OR Infant/ OR asolescen*/ OR “preschool”/
AND
posture*/ OR “biomech*”/ OR “footprint*”/ OR “morphology*”/ OR “navicular height”/ OR “foot posture ind*”/ OR “p?ediatric flat foot proforma”/ OR “arch ind*”/ OR “arch height ind*”/ OR “foot mobility magnitude”/ OR “hindfoot posture”/ OR “arch insert”/ OR “medial arch”/ OR “foot posture measure*”/ OR “foot function ind*”/ OR “p-ffp” [paediatric flat foot proforma]/ OR “pffp” [paediatric flat foot proforma]/ OR “fpi”/ OR “fmm”/
Medical subject headings (MeSH) were exploded, combined with relevant keywords and truncated as necessary. Searches were limited to English language studies. Further studies were sought from a review of reference lists, conference proceedings and personal communications with content experts (Fig. 1). In addition, studies referenced within the final included articles that cited psychometric properties of the measures and criteria used to define flat foot were sourced (Fig. 1).

Eligibility criteria

Studies were included if published in peer-reviewed journals, participants were aged ≤18 years and the outcomes included a definition and measure of flat foot. Table 2 displays the full inclusion and exclusion criteria.
Table 2
Inclusion and exclusion criteria
Inclusion
Exclusion
Sample included individuals with pes planus
Participants with a history of rigid pes planus
Definition of pes planus, with criteria described
> 18 years of age
Conducted/described measures, which were aimed at diagnosing pes planus (e.g. rearfoot posture, arch height and footprint measures)
Participants who had acutely painful or inflammatory conditions (e.g. juvenile arthritis)
Children (≤18 years of age)
 
Empirical studies
 
English language
 
Title, abstract and full-text screening was independently conducted by two investigators (MP, HB/SM) with a third reviewer (CW) consulted in the event of non-agreement (Fig. 1).

Critical appraisal of bias and data extraction

A priori decision was set to include all studies meeting the criteria regardless of potential risk of bias and include all measures of flat foot where validity and reliability measures reached a moderate or above rating (see data management for rating parametres), [22, 24, 25]. Data extraction was in keeping with the aims of the study and included; study design, participant age range, sample size, ethnicity/country of study, foot posture measure(s), flat foot definition and relevant psychometric data related to QAREL and a purpose-built criterion described below.
The outcomes of interest in validity studies were sensitivity, specificity and correlation with a reference standard (e.g. plain film radiographs). Validity was assessed with a purpose-built criterion (Additional file 1), covering: reported validity of the flat foot measure and definition; age (in years) of the test population; differences in the cited protocol reported and included study protocol; and, a pragmatic determination of whether validity was demonstrated for a paediatric population (yes/no/with caution). For example, a yes was assigned if a paediatric sample was used for validity testing, the study protocol matched the cited protocol and sensitivity / specificity or correlations with reference standard were moderate or above; a no would be assigned if the study population was adult or sensitivity/specificity or correlations with reference standard were below moderate. With caution was assigned if the study population had been paediatric but aspects of sensitivity/specificity or correlation with a reference standard had mixed results (Additional file 1).
The reliability outcome of interest was inter-rater agreement. Inter-rater reliability studies were appraised using the QAREL checklist [26, 27] and a purpose-built assessment (Additional file 1). The 11 item QAREL tool assesses: if the test evaluated a sample of representative subjects; was it performed by raters representative of those standardly using the measure; were raters blinded to i) the findings of other raters, ii) their own prior findings iii) the reference standard outcomes, iv) other clinical information, and v) cues that were not part of the procedure; was the order of examination randomised; was the time interval between measures suitable; did they apply the protocol appropriately; and, was the statistical analysis correctly conducted. Each item was scored as yes, no, unclear or not applicable rating. The QAREL score is the number of items that received a ‘yes’ rating (Additional file 1). The purpose-built criteria covered five criteria; definition of flat foot used, age (in years) of the test population; differences in protocol reported between the cited and included article; inter-rater reliability measure and outcome; and, a pragmatic determinant of whether reliability was demonstrated for a paediatric population (yes/no/with caution). The assignment of yes/no/with caution were based on similar outcomes as for validity ratings (Additional file 1).
Two investigators independently extracted data and assessed articles against the QAREL criteria and purpose-built criteria (HB, MP/CW) with any discrepancies resolved by a fourth reviewer (SM).

Data management

Data were synthesized in table form. Correlations with reference standards and inter-rater reliability outcomes were presented as Intraclass Correlation Coefficients (ICCs) [22], kappa coefficients [27] or sensitivity and specificity data [25]. For consistency, outcomes were rated according to Fig. 2. All other responses displayed as descriptive only or awarded a yes/no/with caution response. Outcomes were required to be deemed valid and reliable to be accepted as appropriate.
Due to the heterogeneity of the included studies, a meta-analysis was not conducted. Instead, a descriptive synthesis of the results was undertaken.

Results

Study selection

The search strategy identified 1101 unique titles (Fig. 1). Following screening, a total of 27 articles were included in the review.

Participants

A total of 15,301 child participants were included within the 27 studies (Table 3). Participants ranged between 3 and 18 years of age. Sample sizes ranged from 22 to 5866 (Table 3). In one study, all participants were male [28]. Four studies separated participants into overweight and normal weight groups for analysis [2932]. Ethnicity or country of study was reported in 26 studies, representing 15 different ethnicities or countries (Table 3).
Table 3
Summary of included studies
Author (date)
Study code
N
Study design
Study aim
Participants
Mean age (SD), range in years*
Ethnicity or Country of study
Foot posture measure used
Abolarin et al. (2011)
[45]
560
Cross-sectional
To determine the role of age and type of foot wear as predictors of flatfoot
School children
6–12
Nigerian
Instep
Aharonson, Arcan & Steinback (1992)
[53]
82
Case-series
To establish foot-ground pressure patterns
Children with flexible flat foot
4–6
Caucasian
Rearfoot eversion
Foot ground pressure
Plantarflexion of talus angle
Calcaneal pitch angle
AP talocalcaneal angle
Bok et al. (2016)
[33]
21
Cohort
To evaluate the effects of different foot orthoses inversion angles on plantar pressure during gait
Children with flexible flat foot
9.9 (1.6), 8–13
South Korean
Rearfoot eversion (plus one of the following)
AP talocalcaneal angle
Lateral talocalcaneal angle
Talus-first metatarsal angle
Calcaneal pitch angle
Chang et al. (2014)
[46]
1228
Cohort
To establish a new classification of flatfoot by characteristics of frequency distribution in footprint indices
School children
7.3 (1.1), 6–10
Taiwanese
Staheli arch index
Chippaux-Smirak index
Chen et al. (2011)
[34]
1319
Cohort
To analyse and compare footprint measures of preschool aged children
Children with flexible flat foot
5.2, 3–6
Taiwan
Clarke’s angle
Chippaux-Smirak Index
Staheli arch index
Chen et al. (2014)
[56]
605
Cohort
To determine the prevalence of flatfoot in children with delayed motor development
Children with & without developmental coordination disorder
4.4, 3–7
Taiwanese
Chippaux-Smirak index
Chen et al. (2015)
[54]
21
Cohort
To investigate the effects of foot wear on joint range of motion, ground reaction forces and muscle activity
Children with & without flat foot
6.3, 5–11
Taiwanese
Arch index
Drefus et al. (2017)
[47]
30
Cross-sectional
To determine the intra and inter-rater reliability of the Arch height index
Children
9.6 (2.0), 6–12
United States
Rearfoot eversion
Arch height index (sitting/standing)
Evans and Karimi (2015)
[29]
728
Cross-sectional
To explore the relationship between foot posture and body mass
Over and normal weight children
9.1 (2.4), 3–15
Australia and United Kingdom
FPI-6
Ezema et al. (2014)
[48]
474
Cross-sectional
To determine associated personal characteristics of flatfooted school children
Children
6–10
Nigerian
Staheli arch index
Galli et al. (2014)
[35]
70
Cohort
To determine if children with Down syndrome were characterised by an accentuated external foot rotation in gait
Children with & without Down syndrome
9.6 (1.7), 4–14
Italy
Arch index
Galli et al. (2015)
[36]
64
Cohort
To characterise quantitatively the foot-ground contact parameters during static upright standing
Children with & without cerebral palsy
8.6 (2.4), 5–13
Italy
Arch index
García-Rodríguez et al. (1999)
[49]
1181
Cross-sectional
To estimate prevalence and number of unnecessary treatments of flatfooted children
School children
4–13
Spanish
Plantar footprint
Kothari et al. (2016)
[50]
95
Cross-sectional
To investigate the relationship between foot posture and the proximal joints
Children with & without flat foot
11 (2.9), 8–15
United Kingdom
Arch height index
Morrison, Ferrari & Smillie (2013)
[28]
22
Quasi-RCT
To report clinical findings of foot posture and lower limb hypermobility and evaluate the impact of foot orthoses on spatio-temporal gait parameters.
Male children with developmental coordination disorder
Median age 7.5, 6–11
United Kingdom
FPI-6
Nikolaidou & Boudolos (2006)
[37]
132
Cohort
To develop a footprint-based classification technique for the rational classification of foot types
School children
10.4 (0.9), 9–11
Greek
Arch index
Chippaux-Smirak index
Martirosov’s K index
Clarke’s angle
Pau et al. (2016)
[30]
130
Cohort
To screen plantar pressures during level walking with a backpack among normal, overweight and obese school children
Overweight, obese and normal weight children
9.3 (2.0), 6–13
Italian
Arch index
Pauk, Ihnatouski & Najafi (2014)
[38]
93
Cohort
To assess differences in plantar pressure distributions and reliability of the Clarke’s angle
Children with & without flat foot
12.6 (1.9), 9–16
Poland
Clarke’s angle
Calcaneal pitch
Calcaneal first metatarsal angle
Pauk & Szymul (2014)
[55]
73
Case-control
Comparing vertical ground reaction force data between flat and neutrally aligned feet
Children with & without flat foot
10.8 (3.6), 4–18
Poland
Clarke’s angle
Rearfoot eversion
Pfeiffer et al. (2006)
[39]
835
Cohort
To establish prevalence and cofactors of flatfoot, and estimate number of unnecessary interventions received
Children
3–6
Austrian
Rearfoot eversion
Reimers, Pedersen & Brodersen (1995)
[40]
759
Cohort
To establish foot deformity and triceps surae length in Danish children
Children and adolescents
3–17
Denmark
Chippaux-Smirak index
Selby-Silverstein, Hillstrom & Palisano (2001)
[41]
26
Cohort
To determine if foot orthoses immediately affected gait of children with Down syndrome or excessively pronated feet
Children with flat foot, with & without Down syndrome
3–6
North American
Rearfoot eversion
Stavlas et al. (2005)
[51]
5866
Cross-sectional
To determine foot morphology evolution in children between 6 and 17 years of age
Children
6–17
Greek
Footprint evaluation
Tashiro et al. (2015)
[52]
619
Cross-sectional
To investigate the relationship between toe grip strength and foot posture
Children
11.2 (0.7), 10–12
Japan
Staheli arch index
Twomey et al. (2010)
[42]
52
Cohort
To investigate differences in kinematics during walking gait
Children with & without flat foot
11.2 (1.2), 9–12
Not reported
Clarke’s angle
Arch index
Navicular height
Villarroya et al. (2009)
[31]
116
Case-control
To evaluate the measures of, and foot arch types, in different weight children using radiographic and footprint indices
Obese & non-obese children
Boys 12.4 (1.6), Girls 11.9 (1.5), 9–16.5
Spanish
Clarke’s angle
Chippaux-Smirak index
Calcaneal pitch
Talus-first metatarsal angle
Yan et al. (2013)
[32]
100
Case-control
To examine changes in dynamic plantar pressure distribution in children of different weight
Obese & non-obese children
10.3 (0.7), 7–12
China
Arch index
*where available
AP – anteroposterior, FPI-6 – foot posture index – 6 item, LAC - longitudinal axis of calcaneus, LAF - longitudinal axis of foot, MLA – medial longitudinal arch, NR – not reported, mm – millimetres
Additional information regarding foot posture parametres can be found in Additional file 2

Study design

The majority of included studies were cohort [30, 3344] and cross-sectional [29, 4552], with a respective 13 and 9 of each study design. Of the other five included articles, three were case control [31, 32, 38], one was a case series [53], and one was a quasi-randomised controlled trial [28].

Primary findings

Foot posture measures and definitions

Across the 27 included studies, 20 foot posture measures were used, involving 40 definitions of flat foot (Table 4). Ten of the 27 studies used multiple measures of flat foot. One study featured a novel method of footprint evaluation [51]. Methodological variations existed across studies, with different parameters and angles assessed following measurement, and different methods for obtaining the footprint/angle and determining flat foot (Table 4, Additional file 2).
Table 4
Rating of reported validity and reliability for foot posture measures and definition of flexible flat foot in paediatric populations
Foot posture measure
Study code
Flat foot definition used
Age range of participants in years
Validity as reported in paediatric population
Reliability as reported in paediatric population
Rating of validity/reliability
(Yes/No/With caution)
Plain film radiograph angles
Calcaneal pitch
[33, 53]
<  20°
4–6 & 8–13
Nil
Nil
No/No
[38]
<  23°
4–18
Nil
Nil
No/No
[31]
≤ 15.4°
7–12
NR [57]
Nil
No/No
AP talocalcaneal
[53]
>  25°
4–6
Nil
Nil
No/No
[33]
>  30°
8–13
Nil
Nil
No/No
Plantarflexion of talus
[53]
>  23°
4–6
Nil
Nil
No/No
Lateral talocalcaneal
[33]
>  45°
8–13
Nil
Nil
No/No
Calcaneal first metatarsal
[38]
145°-170°
4–18
Nil
Nil
No/No
Talus-first metatarsal
[33] [31]
>  4°
7–13
Nil
NR [80], NA [64]
No/No
Foot print indices
Arch index
[35, 54], [36]
≥ 0.26
3–6, 5–13, 4–14
Nil
Nil
No/No
[37]
≥ 0.26
10
NR [58]
Substantial [81], NR [37]
No/Yes
[30, 32, 42]
>  0.26
6–13
Nil
Nil
No/No
Chippaux-Smirak
[46]
≥ 59%
6–9
Nil
Excellent [46]
No/Yes
[34]
>  62.7%
3–7
Moderate [34]
NR [65]
With caution/No
[56]
>  62.7%
3–7
Moderate [34]
Nil
With caution/No
[37],
≥ 45%
10
NR [59]
NR [37]
No/No
[40]
≥ 45%
3–17
Nil
Nil
No/No
[31]
≥ 40%
9–16
Moderate [31]
NR [60]
Nil
With caution/No
Clarke’s angle
[34]
≤ 14.04
3–6
Moderate [34]
Nil
With caution/No
[37]
≤ 20°
10
Nil
NR [37, 59]
No/No
[38]
<  42°
9–16
Excellent [38]
Nil
With caution/No
[55]
<  42°
4–18
Nil
Nil
No/No
[31]
<  29.9°
9–16
Moderate [31],NR [60]
Nil
With caution/No
Staheli arch index
[46]
≥ 1.28
6–9
Nil
Excellent [46]
No/Yes
[34]
>  1.07
3–6
Moderate [34]
NR [65]
With caution/No
[48]
>  1.15
6–10
NR [59, 61]
Nil
No/No
[52]
>  0.89
10–12
Nil
Nil
No/No
Footprint index
[42]
<  0.25
9–12
Nil
Nil
No/No
Martirosov’s K index
[37]
≥ 1.25
10
Nil
NR [37]
No/No
Footprint evaluation
[51]
X > Y
6–17
Nil
NR [66]
No/No
Instep
[45]
100 mm
6–12
Nil
Nil
No/No
Plantar footprint
[49]
≥ 50%
4–13
Nil
Nil
No/No
Static foot measures
Rearfoot eversion
[53]
>  10°
4–6
Nil
Nil
No/No
[33]
≥ 4°
8–13
Nil
Nil
No/No
[47]
≥ 4°
6–13
Nil
NA [67]
No/No
[55]
>  5°
4–18
Nil
Nil
No/No
[39]
>  5°
3–6
Nil
NR [68]
No/No
[41]
> (7° - age)
3–6
Nil
Substantial [41]
No/Yes
Arch Height Index
[47]
≤ 0.37
6–13
NR [62]
Substantial [47]NR [82, 83]
No/Yes
[50]
<  0.31
8–15
Nil
Nil
No/No
FPI-6
[29]
≥ + 6
3–15
Not rated^ [63]
Substantial [69]
With caution/Yes
[28]
≥ + 4
6–11
Nil
Excellent [70]
No/Yes
Navicular height
[42]
<  20 mm
9–12
Nil
Nil
No/No
Other measures
Plantar pressure analysis (FGP)
[53]
54%
4–6
Nil
Nil
No/No
AP – anterioposterior, FPI-6 – foot posture index – 6 item version, NR – not reported in cited text, NA – not available, FGP – foot ground pressure
Notes: See data management for ratings of reliability and validity. *See Additional file 1 for rating parametres. ^RASCH analysis
Of the 20 foot posture measures used, six were plain film radiographs of angles including calcaneal pitch (or calcaneal inclination), anterior-posterior talocalcaneal (AP talocalcaneal), plantarflexion of talus, lateral talocalcaneal, calcaneal-first metatarsal and talus-first metatarsal angles (Table 4). Nine were footprint indices (Chippaux-Smirak index, Arch index, Clarke’s angle [or Footprint angle, Alpha angle], Staheli Arch index, Footprint index, Martirosov’s K index, Footprint evaluation, Instep and Plantar footprint), (Table 4). There were four static foot measures (rearfoot eversion, Arch height index, Foot Posture Index–6 item version [FPI-6] and navicular height) and one plantar pressure study [Foot Ground Pressure], (Table 4).
The Arch index was the most frequently used measure (n = 7), with the Chippaux-Smirak index and rearfoot eversion also frequently employed (n = 6 respectively), (Table 4). A further seven measures were used in more than one study (Clarke’s angle (n = 5), Calcaneal pitch and Staheli arch Index (n = 4), and, AP talocalcaneal, Talus-first metatarsal angle, Arch height index and FPI-6 (n = 2 respectively)), (Table 4). Nine alternate assessment measures were used once across the included studies: plantarflexion of talus, lateral talocalcaneal angle, calcaneal-first metatarsal angle, and; Footprint index; Martirosov’s K Index; instep; Plantar Footprint; navicular height; and, Foot Ground Pressure (Table 4).
The most commonly used flat foot definition was the Arch Index ≥0.26, used four times across the 27 included studies. An Arch index of >0.26 was used twice, and ≥0.28 used once in three further studies. A Chippaux-Smirak Index of ≥45 and >62.70% were used twice (n = 2 respectively). Other definitions used twice across the included studies were talus-first metatarsal angle, rearfoot eversion 5° and 4°, and a Clarke’s Angle of <42° (Table 4).
Thirteen of the included 27 studies did not investigate or report the psychometric properties of the measures used to determine paediatric flat foot [30, 32, 33, 35, 36, 40, 45, 49, 50, 5255], (Table 4), leaving 8 of the 20 foot posture measures used within this systematic review without reported validity or reliability outcomes to justify their use. Specifically; plain film radiograph measures of AP talocalcaneal angle, plantarflexion of talus, lateral talocalcaneal angle, calcaneal first metatarsal angle; the Instep; Plantar footprint; navicular height; and, Foot Ground Pressure, (Table 4, Additional file 1).

Quality and appropriateness of reported psychometric properties for a paediatric population

Two studies investigated the validity of the foot posture measures used with their studies [34, 38], five studies [29, 37, 47, 48, 56] justified their choice by citing seven existing studies [5763] and one study did both [31]. No foot posture measures were assessed with a ‘yes’ ranking in relation to their validity for a paediatric population (Table 4, Additional file 1). The Chippaux-Smirak index, Clarke’s angle, Staheli arch index and the FPI-6 respectively were ranked as relevant to a paediatric population ‘with caution’ (Table 4, Additional file 1).
The quality of the reliability testing, in relation to a paediatric population, was also limited. Four studies investigated the reliability of the measure used to determine flat foot within their studies [37, 41, 46, 47], five studies [28, 29, 34, 39, 51] justified their choice by citing seven existing studies [6470] and three studies did both [31, 37, 47]. Two cited articles were not available to assess [64, 67]. The Arch index, Chippaux-Smirak index, Staheli arch index, rearfoot eversion, Arch height index and the FPI-6 received a ‘yes’ ranking as relevant to their reliability for a paediatric population (Table 4, Additional file 1), with only the Chippaux-Smirak index, the Staheli arch index and rearfoot eversion reported as having almost perfect repeatability within this population (Table 4). However, alternative studies investigating the Chippaux-Smirak index, Staheli arch index and the FPI-6, as well as the Clarke’s angle were assessed as relevant to a paediatric population ‘with caution’ (Table 4, Additional file 1).

Summary of results

From the 27 studies included, data were extracted for 20 foot posture measures involving 40 definitions of flat foot within a paediatric population (Table 3). Eight of the included 27 articles investigated the reliability or validity of the flat foot measures used, six further articles justified their choice of measure by citing existing psychometric data and 13 articles neither justified nor reported psychometric properties for their measures of choice (Table 4). Seven measures, involving 11 definitions of flat foot, were determined to have reported validity or reliability specific for a paediatric population (Table 4). Of these measures, no measure had strong data to support validity and reliability of the measure in paediatric samples, and only three were reported to have moderate or with caution validity data and moderate or above reliability data for a paediatric population. Specifically, these three measures were the Chippaux-Smirak index of >63%, ≥59% and ≥40% (for children aged six to nine, three to seven and nine to 16 years respectively), the Staheli arch index of >1.07 and ≥1.28 (for children aged three to six and six to nine respectively) and the FPI-6 of ≥ + 6 (for children aged three to 15 years), (Table 4).

Discussion

There was a modest body of evidence reporting paediatric specific measures of foot posture. There was no consistently used measure to determine paediatric flexible flat foot in the literature and the choice of foot posture measure, in relation to the validity and reliability, was rarely justified. Within the scope of this review, only three measures of flexible flat foot had any published data to support validity and reliability of the measure within a paediatric population; the Chippaux-Smirak index, Staheli arch index and the FPI-6. However, each of these measures were deemed to have limitations.
The Staheli arch and Chippaux-Smirak, used four and six times respectively across this review, are foot print indices, based on the width of the midfoot compared to the width of the rearfoot (Staheli arch) or metatarsals (Chippaux-Smirak), when the foot is in bipedal weight-bearing relaxed stance, expressed as a ratio (Additional file 2). As the child’s arch develops with age, the ratio should decrease accordingly. This is supported by normative data [3]. The definition of flat foot for the Chippaux-Smirak index within this review did decreased linear to age: 62.7% in 3 to 6 year olds, to ≥40% in 9 to 16 year olds (Table 3). However, the definitions of flat foot for the Staheli arch index did not decrease as expected (e.g. >1.07 in 3 to 6 year olds and ≥1.28 in 6 to 9 year olds, Table 3). This finding is not consistent with existing normative data and suggests these definitions should be used with caution. Furthermore, concerns exist that two-dimensional indices are limited in their ability to assess a three-dimensional construct [71]. It is suggested that categorising the foot posture based on footprint data disregards the complexity and multi-planar motion of the foot [3]. This greatly challenges the validity of the measures using this construct. At a minimum, these measures are reportedly influenced by the weight of the participants [72].
The FPI-6 is a composite tool that assesses multiple components of foot posture, relative to the age of the participant, and presents as an overall score between − 12 to + 12 [73], (Additional file 2). The ‘with caution’ rating assigned to the validity of the FPI-6 was due to the results including an adult population [63]. A flat foot definition ≥ + 6 for a paediatric population is well supported in the literature in terms of normative data [3, 69, 74, 75] and it is considered as the only flat foot scale that accommodates differences between normal and overweight/obese children [29]. Furthermore, only the FPI-6 was tested with a broad age range (i.e. children aged 5 to 16 years old [69, 70]). Interestingly, the FPI-6 was only used in two of the include studies [28, 29], despite being the recommended foot posture measure associated with the GALLOP proforma [76] (an opinion and evidence based proforma for assessment of gait and lower limbs in paediatrics).
The topic of paediatric foot posture remains controversial [39, 77] with little consensus on how this frequently observed foot type should be measured, defined or assessed. Importantly, it is acknowledged that a flat foot posture outside of expected norms may not require management. Clinician’s evaluation of the child, directed by a validated tool such as the paediatric flat foot proforma (p-FFP) [15] assist the clinician in determining when intervention may be required. What this review has highlighted, however, is an issue central to the discourse surrounding this topic. That is, much of the evidence that guides clinician assessment and intervention into paediatric flexible flat foot are potentially based on unsubstantiated measures. It is essential this is addressed in future research. Valid and reliable diagnoses of flat foot appropriate to the paediatric population is required to i) inform the clinician when the foot posture is not in keeping with expected development, and ii) allow research to be appropriate and clinically applicable.
Considering the difficulties associated with static foot print analysis, researchers and clinicians may need to consider the FPI-6 or alternative composite tools (such as the foot mobility magnitude model [78]) or dynamic measurement to better understand paediatric foot structure. Indeed, paediatric based studies have shown a significant difference between static structure and dynamic foot function [79] which may be of clinical relevance. As there was a paucity of dynamic measures in the included studies, further investigation may be beneficial. This extends also to a lack of understanding on the ability of these measures to detect change over time. For researchers to adequately assess development of, and intervention effects in, paediatric flexible flat foot, measures need to be robust and applicable.
There are a number of key limitations in this study. Only English language studies were included in the search strategy and the risk of bias of the included studies was not assessed with a specific critical appraisal tool. Many of the included studies did not cite support for their choice of measure or did not cite appropriately. Indeed, many of the studies reporting existing data assumed it was obtained appropriately and transferrable to their study. For example, Villarroya et al. (2009) quoted psychometric data for the Chippaux-Smirak index from the Kanatli, Yetkin and Cila (2001) article, which relates to the validity of the Staheli arch index; and Mathieson et al. (1999) was quoted in Nikolaidou et al. (2006) even though it obtained data from an adult population. Many studies did not describe their methods or population clearly (Table 2), and two texts were unavailable to the authors [64, 67]. Therefore, these results should be interpreted accordingly. This systematic review was also limited by a paucity of literature in relation to foot posture assessment in the paediatric population. Within the limits of this study, even the reference standard measures (e.g. plain film radiographs) had little psychometric data. Although this review had a broad scope, it did not account for studies which looked solely at the psychometric properties of a measure without a definition of pes planus. Therefore, future studies may search for these measures individually. Furthermore, this systematic review process was underpinned by best practice in the conduct of systematic reviews (PRISMA), however, potential publication and language bias should be acknowledged.

Conclusion

A synthesis of available literature reveals that there is not a universally accepted criterion for diagnosing abnormal paediatric flat foot within existing literature, and psychometric data for the measures and definitions used was limited. Within the limits of this review, only three measures of flexible flat foot had any published data to support validity and reliability of the measure within a paediatric population (Chippaux-Smirak index, Staheli arch index and FPI-6), each with their own limitations. Further research into valid and reliable, clinically relevant foot posture measures, including dynamic measures and the influence of age, gender and body mass on flat foot incidence, specifically for the paediatric population, is required. Furthermore, age-specific cut-off values should be further defined.

Funding

CMW is funded by a National Health and Medical Research Council Early Career Research Health Professional Fellowship.

Availability of data and materials

Data sharing not applicable to this article as no datasets were generated or analysed during the current study.
Not applicable.

Competing interests

The authors declare that they have no competing interests.\

Publisher’s Note

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Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://​creativecommons.​org/​licenses/​by/​4.​0/​), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://​creativecommons.​org/​publicdomain/​zero/​1.​0/​) applies to the data made available in this article, unless otherwise stated.
Literatuur
2.
go back to reference Krul M, van der Wouden JC, Schellevis FG, van Suijlekom-Smit LWA, Koes BW. Foot problems in children presented to the family physician: a comparison between 1987 and 2001. Fam Pract. 2009;26:174–9. CrossRefPubMed Krul M, van der Wouden JC, Schellevis FG, van Suijlekom-Smit LWA, Koes BW. Foot problems in children presented to the family physician: a comparison between 1987 and 2001. Fam Pract. 2009;26:174–9. CrossRefPubMed
3.
4.
go back to reference Nemeth B. The diagnosis and management of common childhood orthopedic disorders. Curr Prob Paediatr Ad. 2011;41:2–28. Nemeth B. The diagnosis and management of common childhood orthopedic disorders. Curr Prob Paediatr Ad. 2011;41:2–28.
5.
go back to reference Sadeghi-Demneh E, Azadinia F, Jafarian F, Shamsi F, Melvin JM, Jafarpishe M, Rezaeian Z. Flatfoot and obesity in school-age children: a cross-sectional study. Clin Obes. 2016;6:42–50. CrossRefPubMed Sadeghi-Demneh E, Azadinia F, Jafarian F, Shamsi F, Melvin JM, Jafarpishe M, Rezaeian Z. Flatfoot and obesity in school-age children: a cross-sectional study. Clin Obes. 2016;6:42–50. CrossRefPubMed
6.
go back to reference Halabchi F, Mazaheri R, Mirshahi M, Abbasian L. Pediatric flexible flatfoot; clinical aspects and algorithmic approach. Iran J Pediatr. 2013;23:247–60. PubMedPubMedCentral Halabchi F, Mazaheri R, Mirshahi M, Abbasian L. Pediatric flexible flatfoot; clinical aspects and algorithmic approach. Iran J Pediatr. 2013;23:247–60. PubMedPubMedCentral
7.
go back to reference Mickle KJ, Steele JR, Munro BJ. Is the foot structure of preschool children moderated by gender. J Paediatr Orthoped. 2008;28:593–6. CrossRef Mickle KJ, Steele JR, Munro BJ. Is the foot structure of preschool children moderated by gender. J Paediatr Orthoped. 2008;28:593–6. CrossRef
8.
9.
go back to reference Tenenbaum S, Hershkovich O, Gordon B, Bruck N, Thein R, Derazne E, Tzur D, Shamiss A, Afek A. Flexible pes planus in adolescents: body mass index, body height, and gender--an epidemiological study. Foot Ankle Int. 2013;34:811–7. CrossRefPubMed Tenenbaum S, Hershkovich O, Gordon B, Bruck N, Thein R, Derazne E, Tzur D, Shamiss A, Afek A. Flexible pes planus in adolescents: body mass index, body height, and gender--an epidemiological study. Foot Ankle Int. 2013;34:811–7. CrossRefPubMed
10.
go back to reference Kothari A, Dixon PC, Stebbins J, Zavatsky AB, Theologis T. The relationship between quality of life and foot function in children with flexible flatfeet. Gait Posture. 2015;41:786–90. CrossRefPubMed Kothari A, Dixon PC, Stebbins J, Zavatsky AB, Theologis T. The relationship between quality of life and foot function in children with flexible flatfeet. Gait Posture. 2015;41:786–90. CrossRefPubMed
11.
go back to reference Lin CJ, Lai KA, Kuan TS, Chou YL. Correlating factors and clinical significance of flexible flatfoot in preschool children. J Paediatr Orthoped. 2001;21:378–82. Lin CJ, Lai KA, Kuan TS, Chou YL. Correlating factors and clinical significance of flexible flatfoot in preschool children. J Paediatr Orthoped. 2001;21:378–82.
12.
go back to reference Kosashvili Y, Fridman T, Backstein D, Safir O, Bar Ziv Y. The correlation between pes planus and anterior knee or intermittent low back pain. Foot Ankle Int. 2008;29:910–3. CrossRefPubMed Kosashvili Y, Fridman T, Backstein D, Safir O, Bar Ziv Y. The correlation between pes planus and anterior knee or intermittent low back pain. Foot Ankle Int. 2008;29:910–3. CrossRefPubMed
13.
go back to reference Shibuya N, Jupiter D, Ciliberti L, VanBuren V, Fontaine J. Characteristics of adult flatfoot in the United States. J Foot Ankle Surg. 2010;49 Shibuya N, Jupiter D, Ciliberti L, VanBuren V, Fontaine J. Characteristics of adult flatfoot in the United States. J Foot Ankle Surg. 2010;49
14.
go back to reference Labovitz JM. The algorithmic approach to pediatric flexible pes planovalgus. Clin Podiatr Med Sur. 2006;23:57–76. viii CrossRef Labovitz JM. The algorithmic approach to pediatric flexible pes planovalgus. Clin Podiatr Med Sur. 2006;23:57–76. viii CrossRef
15.
go back to reference Evans AM. The flat-footed child -- to treat or not to treat: what is the clinician to do? J Am Podiatr Med Assoc. 2008;98:386–93. CrossRefPubMed Evans AM. The flat-footed child -- to treat or not to treat: what is the clinician to do? J Am Podiatr Med Assoc. 2008;98:386–93. CrossRefPubMed
16.
go back to reference Chen KC, Yeh CJ, Tung LC, Yang JF, Yang SF, Wang CH. Relevant factors influencing flatfoot in preschool-aged children. Euro J Paediatr. 2011;170:931–6. CrossRef Chen KC, Yeh CJ, Tung LC, Yang JF, Yang SF, Wang CH. Relevant factors influencing flatfoot in preschool-aged children. Euro J Paediatr. 2011;170:931–6. CrossRef
17.
go back to reference Weimar W, Shroyer J. Arch height index normative values of college-aged women using the arch height index measurement system. J Am Podiatr Med Assoc. 2013;103:213–7. CrossRefPubMed Weimar W, Shroyer J. Arch height index normative values of college-aged women using the arch height index measurement system. J Am Podiatr Med Assoc. 2013;103:213–7. CrossRefPubMed
18.
go back to reference Didia BC, Omu ET, Obuoforibo AA. The use of footprint contact index II for classification of flat feet in a Nigerian population. Foot Ankle. 1987;7:285–9. CrossRefPubMed Didia BC, Omu ET, Obuoforibo AA. The use of footprint contact index II for classification of flat feet in a Nigerian population. Foot Ankle. 1987;7:285–9. CrossRefPubMed
19.
go back to reference Gould N, Moreland M, Alvarez R, Trevino S, Fenwick J. Development of the child's arch. Foot Ankle. 1989;9:241–5. CrossRefPubMed Gould N, Moreland M, Alvarez R, Trevino S, Fenwick J. Development of the child's arch. Foot Ankle. 1989;9:241–5. CrossRefPubMed
20.
go back to reference Golafshani N. Understanding reliability and validity in qualitative research. Qual Rep. 2003;8(4):597–606. Golafshani N. Understanding reliability and validity in qualitative research. Qual Rep. 2003;8(4):597–606.
21.
go back to reference Rothwell PM. External validity of randomised controlled trials: "to whom do the results of this trial apply?". Lancet. 2005;365(9453):82–93. CrossRefPubMed Rothwell PM. External validity of randomised controlled trials: "to whom do the results of this trial apply?". Lancet. 2005;365(9453):82–93. CrossRefPubMed
22.
go back to reference Portney LG, Watkins MP. Foundations of clinical research: applications to practice. 3rd ed. edn. Upper Saddle River. In: N.J: Pearson/prentice hall; 2009. Portney LG, Watkins MP. Foundations of clinical research: applications to practice. 3rd ed. edn. Upper Saddle River. In: N.J: Pearson/prentice hall; 2009.
23.
go back to reference Moher D, Liberati A, Tetzlaff J, Altman DG. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. Brit Med J. 2009;339 Moher D, Liberati A, Tetzlaff J, Altman DG. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. Brit Med J. 2009;339
24.
go back to reference McHugh ML. Interrater reliability: the kappa statistic. Biochem Med (Zagreb). 2012;22:276–82. CrossRef McHugh ML. Interrater reliability: the kappa statistic. Biochem Med (Zagreb). 2012;22:276–82. CrossRef
25.
go back to reference Cicchetti DV. The precision of reliability and validity estimates re-visited: distinguishing between clinical and statistical significance of sample size requirements. J Clin Exp Neuropsychol. 2001;23:695–700. CrossRefPubMed Cicchetti DV. The precision of reliability and validity estimates re-visited: distinguishing between clinical and statistical significance of sample size requirements. J Clin Exp Neuropsychol. 2001;23:695–700. CrossRefPubMed
26.
go back to reference Lucas NP, Macaskill P, Irwig L, Bogduk N. The development of a quality appraisal tool for studies of diagnostic reliability (QAREL). J Clin Epidemiol. 2010;63:854–61. CrossRefPubMed Lucas NP, Macaskill P, Irwig L, Bogduk N. The development of a quality appraisal tool for studies of diagnostic reliability (QAREL). J Clin Epidemiol. 2010;63:854–61. CrossRefPubMed
27.
go back to reference Lucas N, Macaskill P, Irwig L, Moran R, Rickards L, Turner R, Bogduk N. The reliability of a quality appraisal tool for studies of diagnostic reliability (QAREL). BMC Med Res Methodol. 2013;13:111. CrossRefPubMedPubMedCentral Lucas N, Macaskill P, Irwig L, Moran R, Rickards L, Turner R, Bogduk N. The reliability of a quality appraisal tool for studies of diagnostic reliability (QAREL). BMC Med Res Methodol. 2013;13:111. CrossRefPubMedPubMedCentral
28.
go back to reference Morrison SC, Ferrari J, Smillie S. Assessment of gait characteristics and orthotic management in children with developmental coordination disorder: preliminary findings to inform multidisciplinary care. Res Dev Disabil. 2013;34:3197–201. CrossRefPubMed Morrison SC, Ferrari J, Smillie S. Assessment of gait characteristics and orthotic management in children with developmental coordination disorder: preliminary findings to inform multidisciplinary care. Res Dev Disabil. 2013;34:3197–201. CrossRefPubMed
29.
go back to reference Evans AM, Karimi L. The relationship between paediatric foot posture and body mass index: do heavier children really have flatter feet? J Foot Ankle Res. 2015;8:46. CrossRefPubMedPubMedCentral Evans AM, Karimi L. The relationship between paediatric foot posture and body mass index: do heavier children really have flatter feet? J Foot Ankle Res. 2015;8:46. CrossRefPubMedPubMedCentral
30.
go back to reference Pau M, Leban B, Corona F, Gioi S, Nussbaum MA. School-based screening of plantar pressures during level walking with a backpack among overweight and obese schoolchildren. Ergonomics. 2016;59:697–703. CrossRefPubMed Pau M, Leban B, Corona F, Gioi S, Nussbaum MA. School-based screening of plantar pressures during level walking with a backpack among overweight and obese schoolchildren. Ergonomics. 2016;59:697–703. CrossRefPubMed
31.
go back to reference Adoracion Villarroya M, Manuel Esquivel J, Tomas C, Buenafe A, Moreno L. Foot structure in overweight and obese children. Int J Pediatr Obes. 2008;3:39–45. CrossRefPubMed Adoracion Villarroya M, Manuel Esquivel J, Tomas C, Buenafe A, Moreno L. Foot structure in overweight and obese children. Int J Pediatr Obes. 2008;3:39–45. CrossRefPubMed
32.
go back to reference Yan S, Zhang K, Tan G, Yang J, Liu Z. Effects of obesity on dynamic plantar pressure distribution in Chinese prepubescent children during walking. Gait Posture. 2013;37:37–42. CrossRefPubMed Yan S, Zhang K, Tan G, Yang J, Liu Z. Effects of obesity on dynamic plantar pressure distribution in Chinese prepubescent children during walking. Gait Posture. 2013;37:37–42. CrossRefPubMed
33.
go back to reference Bok SK, Lee H, Kim BO, Ahn S, Song Y, Park I. The effect of different foot orthosis inverted angles on plantar pressure in children with flexible flatfeet. PLoS One. 2016;11:e0159831. CrossRefPubMedPubMedCentral Bok SK, Lee H, Kim BO, Ahn S, Song Y, Park I. The effect of different foot orthosis inverted angles on plantar pressure in children with flexible flatfeet. PLoS One. 2016;11:e0159831. CrossRefPubMedPubMedCentral
34.
go back to reference Chen KC, Yeh CJ, Kuo JF, Hsieh CL, Yang SF, Wang CH. Footprint analysis of flatfoot in preschool-aged children. Eur J Pediatr. 2011;170:611–7. CrossRefPubMed Chen KC, Yeh CJ, Kuo JF, Hsieh CL, Yang SF, Wang CH. Footprint analysis of flatfoot in preschool-aged children. Eur J Pediatr. 2011;170:611–7. CrossRefPubMed
35.
go back to reference Galli M, Cimolin V, Rigoldi C, Pau M, Costici P, Albertini G. The effects of low arched feet on foot rotation during gait in children with Down syndrome. J Intellect Disabil Res. 2014;58:758–64. CrossRefPubMed Galli M, Cimolin V, Rigoldi C, Pau M, Costici P, Albertini G. The effects of low arched feet on foot rotation during gait in children with Down syndrome. J Intellect Disabil Res. 2014;58:758–64. CrossRefPubMed
36.
go back to reference Galli M, Cimolin V, Pau M, Leban B, Brunner R, Albertini G. Foot pressure distribution in children with cerebral palsy while standing. Res Dev Disabil. 2015;41-42:52–7. CrossRefPubMed Galli M, Cimolin V, Pau M, Leban B, Brunner R, Albertini G. Foot pressure distribution in children with cerebral palsy while standing. Res Dev Disabil. 2015;41-42:52–7. CrossRefPubMed
37.
go back to reference Nikolaidou ME, Boudolos KD. A footprint-based approach for the rational classification of foot types in young schoolchildren. Foot. 2006;16:82–90. 89p. CrossRef Nikolaidou ME, Boudolos KD. A footprint-based approach for the rational classification of foot types in young schoolchildren. Foot. 2006;16:82–90. 89p. CrossRef
38.
go back to reference Pauk J, Ihnatouski M, Najafi B. Assessing plantar pressure distribution in children with flatfoot arch: application of the Clarke angle. J Am Podiatr Med Assoc. 2014;104:622–32. CrossRefPubMed Pauk J, Ihnatouski M, Najafi B. Assessing plantar pressure distribution in children with flatfoot arch: application of the Clarke angle. J Am Podiatr Med Assoc. 2014;104:622–32. CrossRefPubMed
39.
go back to reference Pfeiffer M, Kotz R, Ledl T, Hauser G, Sluga M. Prevalence of flat foot in preschool-aged children. Pediatrics. 2006;118:634–9. CrossRefPubMed Pfeiffer M, Kotz R, Ledl T, Hauser G, Sluga M. Prevalence of flat foot in preschool-aged children. Pediatrics. 2006;118:634–9. CrossRefPubMed
40.
go back to reference Reimers J, Pedersen B, Brodersen A. Foot deformity and the length of the triceps surae in Danish children between 3 and 17 years old. J Pediatr Orthoped. 1995;4:71–3. CrossRef Reimers J, Pedersen B, Brodersen A. Foot deformity and the length of the triceps surae in Danish children between 3 and 17 years old. J Pediatr Orthoped. 1995;4:71–3. CrossRef
41.
go back to reference Selby-Silverstein L, Hillstrom H, Palisano R. The effect of foot orthoses on standing foot posture and gait of young children with Down syndrome. Neurorehabilitation. 2001;16:183–93. PubMed Selby-Silverstein L, Hillstrom H, Palisano R. The effect of foot orthoses on standing foot posture and gait of young children with Down syndrome. Neurorehabilitation. 2001;16:183–93. PubMed
42.
go back to reference Twomey D, McIntosh AS, Simon J, Lowe K, Wolf SI. Kinematic differences between normal and low arched feet in children using the Heidelberg foot measurement method. Gait Posture. 2010;32:1–5. CrossRefPubMed Twomey D, McIntosh AS, Simon J, Lowe K, Wolf SI. Kinematic differences between normal and low arched feet in children using the Heidelberg foot measurement method. Gait Posture. 2010;32:1–5. CrossRefPubMed
43.
go back to reference Chen K-C, Tung L-C, Tung C-H, Yeh C-J, Yang J-F, Wang C-H. An investigation of the factors affecting flatfoot in children with delayed motor development. Res Dev Disabil. 2014;35:639–45. CrossRefPubMed Chen K-C, Tung L-C, Tung C-H, Yeh C-J, Yang J-F, Wang C-H. An investigation of the factors affecting flatfoot in children with delayed motor development. Res Dev Disabil. 2014;35:639–45. CrossRefPubMed
44.
go back to reference Chen JP, Chung MJ, Wu CY, Cheng KW, Wang MJ. Comparison of barefoot walking and shod walking between children with and without flat feet. J Am Podiatr Med Assoc. 2015;105:218–25. CrossRefPubMed Chen JP, Chung MJ, Wu CY, Cheng KW, Wang MJ. Comparison of barefoot walking and shod walking between children with and without flat feet. J Am Podiatr Med Assoc. 2015;105:218–25. CrossRefPubMed
45.
go back to reference Abolarin T, Aiyegbusi A, Tella A, Akinbo S. Predictive factors for flatfoot: the role of age and footwear in children in urban and rural communities in south West Nigeria. Foot. 2011;21:188–92. CrossRef Abolarin T, Aiyegbusi A, Tella A, Akinbo S. Predictive factors for flatfoot: the role of age and footwear in children in urban and rural communities in south West Nigeria. Foot. 2011;21:188–92. CrossRef
46.
go back to reference Chang C-H, Chen Y-C, Yang W-T, Ho P-C, Hwang A-W, Chen C-H, Chang J-H, Chang L-W. Flatfoot diagnosis by a unique bimodal distribution of footprint index in children. PLoS One. 2014;9:e115808. CrossRefPubMedPubMedCentral Chang C-H, Chen Y-C, Yang W-T, Ho P-C, Hwang A-W, Chen C-H, Chang J-H, Chang L-W. Flatfoot diagnosis by a unique bimodal distribution of footprint index in children. PLoS One. 2014;9:e115808. CrossRefPubMedPubMedCentral
47.
go back to reference Drefus LC, Kedem P, Mangan SM, Scher DM, Hillstrom HJ. Reliability of the arch height index as a measure of foot structure in children. Pediatr Phys Ther. 2017;29:83–8. CrossRefPubMed Drefus LC, Kedem P, Mangan SM, Scher DM, Hillstrom HJ. Reliability of the arch height index as a measure of foot structure in children. Pediatr Phys Ther. 2017;29:83–8. CrossRefPubMed
48.
go back to reference Ezema CI, Abaraogu UO, Okafor GO. Flat foot and associated factors among primary school children: a cross-sectional study. Hong Kong Physio J. 2014;32:13–20. CrossRef Ezema CI, Abaraogu UO, Okafor GO. Flat foot and associated factors among primary school children: a cross-sectional study. Hong Kong Physio J. 2014;32:13–20. CrossRef
49.
go back to reference Garcia-Rodriguez A, Martin-Jimenez F, Carnero-Varo M, Gomez-Gracia E, Gomez-Aracena J, Fernandez-Crehuet J. Flexible flat feet in children: a real problem. Pediatr. 1999;103:e84. CrossRef Garcia-Rodriguez A, Martin-Jimenez F, Carnero-Varo M, Gomez-Gracia E, Gomez-Aracena J, Fernandez-Crehuet J. Flexible flat feet in children: a real problem. Pediatr. 1999;103:e84. CrossRef
50.
go back to reference Kothari A, Dixon PC, Stebbins J, Zavatsky AB, Theologis T. Are flexible flat feet associated with proximal joint problems in children. Gait Posture. 2016;45:204–10. CrossRefPubMed Kothari A, Dixon PC, Stebbins J, Zavatsky AB, Theologis T. Are flexible flat feet associated with proximal joint problems in children. Gait Posture. 2016;45:204–10. CrossRefPubMed
51.
go back to reference Stavlas P, Grivas TB, Michas C, Vasiliadis E, Polyzois V. The evolution of foot morphology in children between 6 and 17 years of age: a cross-sectional study based on footprints in a Mediterranean population. J Foot Ankle Sur. 2005;44:424–8. CrossRef Stavlas P, Grivas TB, Michas C, Vasiliadis E, Polyzois V. The evolution of foot morphology in children between 6 and 17 years of age: a cross-sectional study based on footprints in a Mediterranean population. J Foot Ankle Sur. 2005;44:424–8. CrossRef
52.
go back to reference Yuto T, Takahiko F, Daisuke U, Daisuke M, Shu N, Naoto F, Daiki A, Takayuki H, Saori M, Hidehiko S, et al. Children with flat feet have weaker toe grip strength than those having a normal arch. J Phys Ther Sci. 2015;27:3533–6. CrossRef Yuto T, Takahiko F, Daisuke U, Daisuke M, Shu N, Naoto F, Daiki A, Takayuki H, Saori M, Hidehiko S, et al. Children with flat feet have weaker toe grip strength than those having a normal arch. J Phys Ther Sci. 2015;27:3533–6. CrossRef
53.
go back to reference Aharonson Z, Arcan M, Steinback T. Foot-ground pressure pattern of flexible flatfoot in children, with and without correction of calcaneovalgus. Clin Orthoped Rel Res. 1992:177 - 182. Aharonson Z, Arcan M, Steinback T. Foot-ground pressure pattern of flexible flatfoot in children, with and without correction of calcaneovalgus. Clin Orthoped Rel Res. 1992:177 - 182.
54.
go back to reference Chen J, Chung M, Wu C, Cheng K, Wang M. Comparison of barefoot walking and shod walking between children with and without flat feet. J Am Podiatr Med Assoc. 2015;105:218–25. CrossRefPubMed Chen J, Chung M, Wu C, Cheng K, Wang M. Comparison of barefoot walking and shod walking between children with and without flat feet. J Am Podiatr Med Assoc. 2015;105:218–25. CrossRefPubMed
55.
go back to reference Pauk J, Szymul J. Differences in pediatric vertical ground reaction force between planovalgus and neutrally aligned feet. Acta of Bioengineer Biomech. 2014;16:95–101. Pauk J, Szymul J. Differences in pediatric vertical ground reaction force between planovalgus and neutrally aligned feet. Acta of Bioengineer Biomech. 2014;16:95–101.
56.
go back to reference Chen KC, Tung LC, Tung CH, Yeh CJ, Yang JF, Wang CH. An investigation of the factors affecting flatfoot in children with delayed motor development. Res Dev Disabil. 2014;35:639–45. CrossRefPubMed Chen KC, Tung LC, Tung CH, Yeh CJ, Yang JF, Wang CH. An investigation of the factors affecting flatfoot in children with delayed motor development. Res Dev Disabil. 2014;35:639–45. CrossRefPubMed
57.
58.
go back to reference McCrory JL, Young MJ, Boulton AJM, Cavanagh PR. Arch index as a predictor of arch height. Foot. 1997;7:79–81. CrossRef McCrory JL, Young MJ, Boulton AJM, Cavanagh PR. Arch index as a predictor of arch height. Foot. 1997;7:79–81. CrossRef
59.
go back to reference Mathieson I, Upton D, Birchenough A. Comparison of footprint parameters calculated from static and dynamic footprints. Foot. 1999;9:145–9. CrossRef Mathieson I, Upton D, Birchenough A. Comparison of footprint parameters calculated from static and dynamic footprints. Foot. 1999;9:145–9. CrossRef
60.
go back to reference Kanatli U, Yetkin H, Cila E. Footprint and radiographic analysis of the feet. J Pediatr Orthoped. 2001;21:225–8. Kanatli U, Yetkin H, Cila E. Footprint and radiographic analysis of the feet. J Pediatr Orthoped. 2001;21:225–8.
61.
go back to reference Cavanagh PR, Rodgers MM. The arch index: a useful measure from footprints. J Biomech. 1987;20:547–51. CrossRefPubMed Cavanagh PR, Rodgers MM. The arch index: a useful measure from footprints. J Biomech. 1987;20:547–51. CrossRefPubMed
62.
go back to reference Hillstrom H, Song J, Kraszewski A, Hafer J, Mootanah R, Dudour A, Chow B. Foot type biomechanics part 1: structure and function of the asymptomatic foot. Gait Posture. 2013;37:445–51. CrossRefPubMed Hillstrom H, Song J, Kraszewski A, Hafer J, Mootanah R, Dudour A, Chow B. Foot type biomechanics part 1: structure and function of the asymptomatic foot. Gait Posture. 2013;37:445–51. CrossRefPubMed
63.
go back to reference Keenan A, Redmond AC, Horton M, Conaghan PG, Tennant A. The foot posture index: Rasch analysis of a novel, foot-specific outcome measure. Arch Phys Med Rehab. 2007;88:88–93. 86p. CrossRef Keenan A, Redmond AC, Horton M, Conaghan PG, Tennant A. The foot posture index: Rasch analysis of a novel, foot-specific outcome measure. Arch Phys Med Rehab. 2007;88:88–93. 86p. CrossRef
64.
go back to reference Staheli LT, Chew DE, Corbett M. The longitudinal arch. A survey of eight hundred and eighty-two feet in normal children and adults. J Bone Joint Surg Am. 1987;69:426–8. CrossRefPubMed Staheli LT, Chew DE, Corbett M. The longitudinal arch. A survey of eight hundred and eighty-two feet in normal children and adults. J Bone Joint Surg Am. 1987;69:426–8. CrossRefPubMed
65.
go back to reference Queen RM, Mall NA, Hardaker WM, Nunley JA 2nd. Describing the medial longitudinal arch using footprint indices and a clinical grading system. Foot Ankle Int. 2007;28:456–62. CrossRefPubMed Queen RM, Mall NA, Hardaker WM, Nunley JA 2nd. Describing the medial longitudinal arch using footprint indices and a clinical grading system. Foot Ankle Int. 2007;28:456–62. CrossRefPubMed
66.
go back to reference Forriol F, Pascual J. Footprint analysis between three and seventeen years of age. Foot Ankle. 1990;11:101–4. CrossRefPubMed Forriol F, Pascual J. Footprint analysis between three and seventeen years of age. Foot Ankle. 1990;11:101–4. CrossRefPubMed
67.
go back to reference Joshi R, Smita R, Song J, Backus S, Sootanah R, H H (Eds.): Structure and function of the foot: Wolters Sluwer/Lippincott Williams & Wilkins 2013. Joshi R, Smita R, Song J, Backus S, Sootanah R, H H (Eds.): Structure and function of the foot: Wolters Sluwer/Lippincott Williams & Wilkins 2013.
68.
go back to reference Sobel E, Levitz S, Caselli M, Brentnall Z, Tran MQ. Natural history of the Rearfoot angle: preliminary values in 150 children. Foot Ankle Int. 1999;20:119–25. CrossRefPubMed Sobel E, Levitz S, Caselli M, Brentnall Z, Tran MQ. Natural history of the Rearfoot angle: preliminary values in 150 children. Foot Ankle Int. 1999;20:119–25. CrossRefPubMed
69.
go back to reference Evans AM, Rome K, Peet L. The foot posture index, ankle lunge test, Beighton scale and the lower limb assessment score in healthy children: a reliability study. J Foot Ankle Res. 2012;5(1) Evans AM, Rome K, Peet L. The foot posture index, ankle lunge test, Beighton scale and the lower limb assessment score in healthy children: a reliability study. J Foot Ankle Res. 2012;5(1)
70.
go back to reference Morrison SC, Ferrari J. Inter-rater reliability of the foot posture index (FPI-6) in the assessment of the paediatric foot. J Foot Ankle Res. 2009;2:26. CrossRefPubMedPubMedCentral Morrison SC, Ferrari J. Inter-rater reliability of the foot posture index (FPI-6) in the assessment of the paediatric foot. J Foot Ankle Res. 2009;2:26. CrossRefPubMedPubMedCentral
72.
go back to reference Gijon-Nogueron G, Montes-Alguacil J, Martinez-Nova A, Alfageme-Garcia P, Cervera-Marin JA, Morales-Asencio JM. Overweight, obesity and foot posture in children: a cross-sectional study. J Paediatr Child Health. 2017;53:33–7. CrossRefPubMed Gijon-Nogueron G, Montes-Alguacil J, Martinez-Nova A, Alfageme-Garcia P, Cervera-Marin JA, Morales-Asencio JM. Overweight, obesity and foot posture in children: a cross-sectional study. J Paediatr Child Health. 2017;53:33–7. CrossRefPubMed
73.
go back to reference Redmond AC, Crosbie J, Ouvrier RA. Development and validation of a novel rating system for scoring standing foot posture: the foot posture index. Clin Biomech. 2006;21:89–98. CrossRef Redmond AC, Crosbie J, Ouvrier RA. Development and validation of a novel rating system for scoring standing foot posture: the foot posture index. Clin Biomech. 2006;21:89–98. CrossRef
75.
go back to reference Evans AM, Copper AW, Scharfbillig RW, Scutter SD, Williams MT. Reliability of the foot posture index and traditional measures of foot position. J Am Podiatr Med Assoc. 2003;93:203–13. CrossRefPubMed Evans AM, Copper AW, Scharfbillig RW, Scutter SD, Williams MT. Reliability of the foot posture index and traditional measures of foot position. J Am Podiatr Med Assoc. 2003;93:203–13. CrossRefPubMed
76.
go back to reference Cranage S, Banwell H, Williams CM. Gait and lower limb observation of Paediatrics (GALLOP): development of a consensus based paediatric podiatry and physiotherapy standardised recording proforma. J Foot Ankle Res. 2016;9:8. CrossRefPubMedPubMedCentral Cranage S, Banwell H, Williams CM. Gait and lower limb observation of Paediatrics (GALLOP): development of a consensus based paediatric podiatry and physiotherapy standardised recording proforma. J Foot Ankle Res. 2016;9:8. CrossRefPubMedPubMedCentral
77.
78.
go back to reference McPoil T, Vicenzino B, Cornwall M, Collins N, Warren M. Reliability and normative values for the foot mobility magnitude: a composite measure of vertical and medial-lateral mobility of the midfoot. J Foot Ankle Res. 2009;2:6. CrossRefPubMedPubMedCentral McPoil T, Vicenzino B, Cornwall M, Collins N, Warren M. Reliability and normative values for the foot mobility magnitude: a composite measure of vertical and medial-lateral mobility of the midfoot. J Foot Ankle Res. 2009;2:6. CrossRefPubMedPubMedCentral
79.
go back to reference Barisch-Fritz B, Schmeltzpfenning T, Plank C, Grau S. Foot deformation during walking: differences between static and dynamic 3D foot morphology in developing feet. Ergonomics. 2013;56:921–33. 913p Barisch-Fritz B, Schmeltzpfenning T, Plank C, Grau S. Foot deformation during walking: differences between static and dynamic 3D foot morphology in developing feet. Ergonomics. 2013;56:921–33. 913p
80.
go back to reference Younger AS, Sawatzky B, Dryden P. Radiographic assessment of adult flatfoot. Foot Ankle Int. 2005;26:820–5. CrossRefPubMed Younger AS, Sawatzky B, Dryden P. Radiographic assessment of adult flatfoot. Foot Ankle Int. 2005;26:820–5. CrossRefPubMed
81.
go back to reference Gilmour J, Burns Y. The measurement of the medial longitudinal arch in children. Foot Ankle Int. 2001;22:493–8. CrossRefPubMed Gilmour J, Burns Y. The measurement of the medial longitudinal arch in children. Foot Ankle Int. 2001;22:493–8. CrossRefPubMed
82.
go back to reference Butler RJ, Hillstrom H, Song J, Richards CJ, Davis IS. Arch height index measurement system: establishment of reliability and normative values. J Am Podiatr Med Assoc. 2008;98:102–6. CrossRefPubMed Butler RJ, Hillstrom H, Song J, Richards CJ, Davis IS. Arch height index measurement system: establishment of reliability and normative values. J Am Podiatr Med Assoc. 2008;98:102–6. CrossRefPubMed
83.
Metagegevens
Titel
Paediatric flexible flat foot: how are we measuring it and are we getting it right? A systematic review
Auteurs
Helen A. Banwell
Maisie E. Paris
Shylie Mackintosh
Cylie M. Williams
Publicatiedatum
01-12-2018
Uitgeverij
BioMed Central
Gepubliceerd in
Journal of Foot and Ankle Research / Uitgave 1/2018
Elektronisch ISSN: 1757-1146
DOI
https://doi.org/10.1186/s13047-018-0264-3

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