The Foot Posture Index: Rasch Analysis of a Novel, Foot-Specific Outcome Measure

A four-week minimalist shoe walking intervention influences foot posture and balance in young adults-a randomized controlled trial

INTRODUCTION

Minimalist shoes (MS) are beneficial for foot health. The foot is a part of the posterior chain. It is suggested that interventions on the plantar foot sole also affect the upper segments of the body. This study aimed to investigate the local and remote effects along the posterior chain of four weeks of MS walking in recreationally active young adults.

METHODS

28 healthy participants (15 female, 13 male; 25.3 ± 5.3 years; 70.2 ± 11.9 kg; 175.0 ± 7.8 cm) were randomly assigned to a control- or intervention group. The intervention group undertook a four-week incremental MS walking program, which included 3,000 steps/day in the first week, increasing to 5,000 steps/day for the remaining three weeks. The control group walked in their preferred shoe (no MS). We assessed the following parameters in a laboratory at baseline [M1], after the four-week intervention [M2], and after a four-week wash-out period [M3]: Foot parameters (i.e., Foot Posture Index-6, Arch Rigidity Index), static single-leg stance balance, foot-, ankle-, and posterior chain range of motion, and muscle strength of the posterior chain. We fitted multiple hierarchically built mixed models to the data.

RESULTS

In the MS group, the Foot Posture Index (b = -3.72, t(51) = -6.05, p < .001, [-4.94, 2.51]) and balance (b = -17.96, t(49) = -2.56, p = .01, [-31.54, 4.37]) significantly improved from M1 to M2, but not all other parameters (all p >.05). The improvements remained at M3 (Foot Posture Index: b = -1.71, t(51) = -2.73, p = .009, [-4,94,0.48]; balance: b = -15.97, t(49) = -2.25, p = .03, [-29.72, 2.21]).

DISCUSSION

Walking in MS for four weeks might be advantageous for foot health of recreationally active young adults but no chronic remote effects should be expected.

Effects of foot exercises and customized arch support insoles on foot posture, plantar force distribution, and balance in people with flexible flatfoot: A randomized controlled trial

BACKGROUND

Exercises strengthening foot muscles and customized arch support insoles are recommended for improving foot posture in flexible flatfoot. However, it is not known what the effects of exercises and insoles on plantar force distribution obtained during walking at different speeds. Also, randomized controlled trials comparing the effects of exercises and insoles are limited.

RESEARCH QUESTION

What are the effects of foot exercises, customized arch support insoles, and exercises plus insoles on foot posture, plantar force distribution, and balance in people with flexible flatfoot? Do exercises, insoles, and exercises plus insoles affect outcome measures differently?

METHODS

Forty-five people with flexible flatfoot were randomly divided into three groups and 40 of those completed the study. The exercise group performed tibialis posterior strengthening and short foot exercises three days a week for six weeks. The insole group used their customized arch support insoles for six weeks. The exercise plus insole group received both interventions for six weeks. The assessments were performed three times: before the interventions and at the 6th and 12th weeks. Outcome measures were (1) foot posture, (2) plantar force distribution in the following conditions: static standing, barefoot walking at different speeds, and walking immediately after the heel-rise test, and (3) balance.

RESULTS

Foot posture improved in all groups, but insole was less effective than exercise and exercise plus insole (p<0.05). Plantar force variables obtained during standing and walking changed in all groups (p<0.05). The superiority of the interventions differed according to the plantar regions and walking speed conditions (p<0.05). Static balance improved in all groups, but limits of stability improved in the exercise plus insole and exercise groups (p<0.05).

SIGNIFICANCE

The superiority of the interventions differed according to the assessed parameter. The management of flexible flatfoot should be tailored based on the assessment results of each individual.

Reliability and measurement error of a maximal voluntary toe plantarflexion measurement process

Despite the growing interest, information regarding the psychometric properties of maximal voluntary isometric toe plantarflexion force and rate of force development (RFD) is lacking. Hence, we investigate the test-retest reliability and measurement error of these outcome measurement instruments measured with a custom-built dynamometer. Twenty-six healthy adults participated in a crossed design with four sessions separated by 5-7 days. RFD was quantified using manual onset and calculating the impulse and the slope in the following time windows: 0-50 ms, 0-100 ms, 0-150 ms, 0-200 ms, 0-250 ms. We estimated the systematic bias of the mean, the intraclass correlation coefficient (ICC) and standard error of measurement (SEM) from the agreement and consistency models. The ICC and the SEM agreement for maximal voluntary isometric toe plantarflexion force along the perpendicular axis were respectively 0.87 (95%CI: 0.76, 0.93) and 27 N (22, 32), while along the resultant of the perpendicular and anterior posterior axis they were 0.85 (0.73, 0.92) and 29 N (23, 35). The results of the consistency model were similar as the estimated variance for session was closer to zero. A systematic bias of the mean between session 1 and 3 was found. For the RFD variables, the ICC agreement ranged from 0.35 to 0.65. The measurement process was found to be reliable to assess maximal voluntary isometric toe plantarflexion force but not RFD. However, a familiarization session is mandatory and these results need to be confirmed in less coordinated (e.g. aging population) individuals.

Toward subtalar joint axis-driven computer-aided design and computer-aided manufacturing foot orthoses: Reliability of a noninvasive clinical scanning protocol

BACKGROUND

The subtalar joint axis (STJA) occupies a key role in the dynamics of the lower limb kinetic chain, and its location has a wide interindividual variability. It has been suggested that considering the STJA location when designing foot orthoses may help to apply the required mechanical dose. However, the evidence is more anecdotal than empirical.

OBJECTIVE

This study aimed to evaluate the reliability of the STJA digitization, a procedure combining the clinical determination of the functional STJA location and its subsequent 3-dimensional (3D) scanning.

STUDY DESIGN

Two examiners identified the posterior and anterior exit points of the functional STJA on the skin of 15 healthy participants using a clinical method in a repeated-measure design.

METHODS

A handheld 3D scanner was used to scan the feet and the skin markers. The 3D coordinates of the skin markers were subsequently quantified and (1) STJA digitization intratester within-session, (2) STJA digitization intratester between-session, and (3) STJA digitization intertester between-session reliabilities were evaluated.

RESULTS

When pooling all skin marker 3D coordinates, intraclass correlation coefficients (ICCs) for the STJA intratester within-session reliability ranged from 0.74 to 0.98. ICCs for the STJA digitization intratester between-session reliability ranged from 0.58 to 0.94. ICCs for the STJA digitization intertester reliability ranged from 0.56 to 0.81. Standard error of measurement for the mediolateral position of the talus marker (anterior exit point of the STJA) was substantially higher than that for the other coordinates.

CONCLUSIONS

Overall, the STJA digitization demonstrated a good intratester between-session reliability and may be used in a computer-aided design and computer-aided manufacturing workflow to create foot orthoses. However, further efforts should be considered to improve the scanning process and intertester reliability.

A randomised controlled trial investigating the effect of foot orthoses for the treatment of chronic nonspecific low back pain

OBJECTIVES

The primary aim was to investigate the effect of prefabricated foot orthoses on pain and function in people with chronic nonspecific low back pain (LBP). Secondary aims were to report on the recruitment rate, adherence to and safety of these interventions, and the relationship between physical activity and pain and function.

DESIGN

A two-arm parallel group (intervention vs. control) randomised (1:1) controlled trial.

SUBJECTS

Forty-one participants with chronic nonspecific LBP.

INTERVENTION

Twenty participants were randomised to the intervention group (prefabricated foot orthotic and The Back Book) and 21 to the control group (The Back Book). The primary outcomes for this study were change in pain and function from baseline to 12 weeks.

RESULTS

No statistically significant difference in pain was found between the intervention and control group (adjusted mean difference -0.84, 95% CI: -2.09 to 0.41, p = 0.18) at the 12-week follow-up. No statistically significant difference in function was found between the intervention and control group (adjusted mean difference -1.47, 95% CI: -5.51 to 2.57, p = 0.47) at the 12-week follow-up.

CONCLUSION

This study found no evidence of a significant beneficial effect of prefabricated foot orthoses for chronic nonspecific LBP. This study demonstrated that the rate of recruitment, intervention adherence and safety, and participant retention is acceptable and supportive of conducting a larger randomised controlled trial. Australian and New Zealand Clinical Trials Registry (ACTRN12618001298202).

Translation, Cross-Cultural Adaptation, and Validation of the Foot Posture Index (FPI-6)-Italian Version

Since foot posture is one of the main predictors of lower limb musculoskeletal injuries, it is crucial to use appropriate tools to define the foot's posture. The Foot Posture Index is, therefore, a reliable method to measure foot posture and is widely known and used in clinics and research. This study aimed to translate the Foot Posture Index 6 (FPI6) into Italian and to assess its psychometric properties. Translation and cross-cultural adaptation were obtained using a popular guideline. Two examinators assessed 68 subjects, and data were collected to test intra/inter-rater reliability, internal consistency and cross-cultural validity. The Italian version of FPI6 showed excellent inter- and intra-rater reliability (ICC 0.96 and 0.97), and Cronbach's alpha coefficient was 0.9, thus showing excellent internal consistency. The FPI-6 version has proved to be reliable in terms of inter- and intra-rater reliability and can, therefore, be used in clinical practice and scientific research.

The Use of Visual Analysis for Gait and Foot Posture in Children with Developmental Dysplasia of the Hip

BACKGROUND

Developmental dysplasia of the hip (DDH) is recognized as a leading cause of significant long-term complications, including inaccurate gait patterns, persistent pain, and early regressive joint disorder, and it can influence families functionally, socially, and psychologically.

METHODS

This study aimed to determine foot posture and gait analysis across patients with developmental hip dysplasia. We retrospectively reviewed participants referred to the pediatric rehabilitation department of KASCH from the orthopedic clinic between 2016 and 2022 (patients born 2016-2022) with DDH for conservative brace treatment.

RESULTS

The foot postural index for the right foot showed a mean of 5.89 (n = 203, SD 4.15) and the left food showed a mean of 5.94 (n = 203, SD 4.19). The gait analysis mean was 6.44 (n = 406, SD 3.84). The right lower limb mean was 6.41 (n = 203, SD 3.78), and the left lower limb mean was 6.47 (n = 203, SD 3.91). The correlation for general gait analysis was r = 0.93, presenting the very high impact of DDH on gait. Significant correlation results were found between the right (r = 0.97) and left (r = 0.25) lower limbs. Variation between the right and left lower limb p-values was 0.88 (p < 0.05). DDH affects the left lower limb more than the right during gait.

CONCLUSION

We conclude that there is a higher risk of developing foot pronation on the left side, which is altered by DDH. Gait analysis has shown that DDH affects the right lower limb more than the left. The results of the gait analysis showed gait deviation in the sagittal mid- and late stance phases.

Incidence and risk factors for patellofemoral dislocation in adults with Charcot-Marie-Tooth disease: An observational study

BACKGROUND AND PURPOSE

Patellofemoral (PF) dislocation is frequently encountered in clinical practice among people with Charcot-Marie-Tooth disease (CMT), but the frequency and risk factors for PF dislocation in adults with CMT are unknown. This study aimed to establish the incidence of PF dislocation in adults with CMT and to explore the risk factors associated with PF dislocation.

METHODS

This is a cross-sectional study involving adults with a diagnosis of CMT, attending their outpatient clinics at a specialist neuromuscular centre in the United Kingdom. Eighty-one individuals were interviewed about any PF dislocation and underwent a lower-limb assessment, with a focussed knee examination, to identify possible risk factors for PF dislocation. The incidence of PF dislocation was expressed as a percentage (number of individuals with a positive history of patellar dislocation/overall sample) and the association between different risk factors and PF dislocation was explored using logistic regression analysis.

RESULTS

The incidence of PF dislocation was 22.2% (18/81). PF dislocation was associated with a younger age at the time of the assessment (p = 0.038) and earlier disease onset (p = 0.025). All people bar two who dislocated had CMT1A (88.9%), but there was no difference in terms of CMT distribution with the non-dislocation group (p = 0.101). No association was found between PF dislocation and CMT severity measured by CMTSS (p = 0.379) and CMTES (p = 0.534). Patella alta (p = 0.0001), J-sign (p = 0.004), lateral patellar glide (p = 0.0001), generalised joint hypermobility (p = 0.001) and knee flexors weakness (p = 0.008) were associated with an increased risk of dislocation. Patella alta (p = 0.010) and lateral patellar glide (p = 0.028) were independent PF dislocation predictors.

CONCLUSIONS

PF dislocation was common in this cohort with CMT and was associated with multiple risk factors. Future studies should be conducted to confirm the present findings so that the identified risk factors may be addressed by clinicians through preventive, supportive and corrective measures.

Reliability of foot posture index (FPI-6) for evaluating foot posture in patients with knee osteoarthritis

Objective: To determine the reliability of FPI-6 in the assessment of foot posture in patients with knee osteoarthritis (KOA). Methods: Thirty volunteers with KOA (23 females, 7 males) were included in this study, assessed by two raters and at three different moments. Inter-rater and test-retest reliability were assessed with Cohen's Weighted Kappa (Kw) and Intraclass Correlation Coefficient (ICC). Bland-Altman plots and respective 95% limits of agreement (LOA) were used to assess both inter-rater and test-retest agreement and identify systematic bias. Moreover, the internal consistency of FPI-6 was assessed by Spearman's correlation coefficient. Results: FPI-6 total score showed a substantial inter-rater (Kw = .66) and test-retest reliability (Kw = .72). The six items of FPI-6 demonstrated inter-rater and test-retest reliability varying from fair to substantial (Kw = .33 to .76 and Kw = .40 to .78, respectively). Bland-Altman plots and respective 95% LOA indicated that there appeared no systematic bias and the acceptable agreement of FPI-6 total score for inter-rater and test-retest was excellent. There was a statistically significant positive correlation between each item and the total score of FPI-6, which indicated that FPI-6 had good internal consistency. Conclusion: In conclusion, the reliability of FPI-6 total score and the six items of FPI-6 were fair to substantial. The results can provide a reliable way for clinicians and researchers to implement the assessment of foot posture in patients with KOA.

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.

Reliability and validity of Foot Posture Index (FPI-6) for evaluating foot posture in participants with low back pain

Previous studies have demonstrated that Foot Posture Index (FPI-6) is a valid and moderately reliable tool to evaluate foot posture. However, data about reliability and validity of FPI-6 in the assessment of foot posture in people with low back pain (LBP) is lacking. To investigate reliability and validity of FPI-6 in the assessment of foot posture in people with LBP. Thirty volunteers with LBP, aged 20-64 years, were recruited for the research and assessed by two raters. The data measured by different raters on the same day were used to calculate the inter-rater reliability. The data measured by the same rater on different dates were used to calculate the test-retest reliability. The reliability of FPI-6 was tested with intraclass correlation coefficient (ICC), and absolute reliability with standard error of measurement (SEM), minimal detectable change (MDC) and Bland-Altman analysis. The validity of FPI-6 was tested with Exploratory Factor Analysis (EFA) and Spearman's correlation coefficients. The FPI-6 indicated excellent inter-rater and test-retest reliability in the evaluation of foot posture in people with LBP (ICC = 0.97 and 0.95). The agreement for inter-rater and test-retest was excellent based on the SEM (SEM = 0.12) and MDC value (MDC = 0.33). Bland-Altman plots showed that there was no significant systematic bias for the agreement on the ground of low mean difference (< 1). The EFA suggested that the fit indices were considered acceptable according to the Kaiser-Meyer-Olkin (KMO) value (KMO = 0.620) and Bartlett's sphericity test (P < 0.01). There was a statistically significant positive correlation between each item and total score of FPI-6 because the Spearman's correlation coefficient of six items were all > 0.3 (P < 0.01). The inter-rater and test-retest reliability and validity of FPI-6 on people with LBP were proved reliable. It might be considered a reliable and valid adjunctive tool to detect possible changes of foot posture after interventions in patients with LBP.

Evaluation methods to assess the efficacy of equinovarus foot surgery on the gait of post-stroke hemiplegic patients: A literature review

Introduction

The aim of this study was to realize a systematic review of the different ways, both clinical and instrumental, used to evaluate the effects of the surgical correction of an equinovarus foot (EVF) deformity in post-stroke patients.

Methods

A systematic search of full-length articles published from 1965 to June 2021 was performed in PubMed, Embase, CINAHL, Cochrane, and CIRRIE. The identified studies were analyzed to determine and to evaluate the outcomes, the clinical criteria, and the ways used to analyze the impact of surgery on gait pattern, instrumental, or not.

Results

A total of 33 studies were included. The lack of methodological quality of the studies and their heterogeneity did not allow for a valid meta-analysis. In all, 17 of the 33 studies involved exclusively stroke patients. Ten of the 33 studies (30%) evaluated only neurotomies, one study (3%) evaluated only tendon lengthening procedures, 19 studies (58%) evaluated tendon transfer procedures, and only two studies (6%) evaluated the combination of tendon and neurological procedures. Instrumental gait analysis was performed in only 11 studies (33%), and only six studies (18%) combined it with clinical and functional analyses. Clinical results show that surgical procedures are safe and effective. A wide variety of different scales have been used, most of which have already been validated in other indications.

Discussion

Neuro-orthopedic surgery for post-stroke EVF is becoming better defined. However, the method of outcome assessment is not yet well established. The complexity in the evaluation of the gait of patients with EVF, and therefore the analysis of the effectiveness of the surgical management performed, requires the integration of a patient-centered functional dimension, and a reliable and reproducible quantified gait analysis, which is routinely usable clinically if possible.

Reliability and Validity of the Knee Injury and Osteoarthritis Outcome Score in Patients Undergoing Unicompartmental Knee Arthroplasty

BACKGROUND

The Knee Injury and Osteoarthritis Outcome Score (KOOS) was developed to document outcomes from knee injury, including the impact of osteoarthritis on knee function. The purpose of this study is to determine the reliability and validity of the KOOS subscales for evaluating outcomes following unicompartmental knee arthroplasty (UKA).

METHODS

KOOS Pain, Activities of Daily Living (ADL), Sport, Symptoms, and Quality of Life (QoL) scores collected from 172 patients who underwent UKA were used in the analysis. KOOS subscales were tested for reliability and validity of scores through a Rasch model analysis.

RESULTS

KOOS Sport, KOOS ADL, and KOOS QoL had good evidence of reliability with acceptable person reliability, person separation, and item reliability. For overall scale functioning, KOOS Pain, Symptoms, and ADL all had 1 question that did not have an acceptable value for infit or outfit mean square value. Questions in KOOS Sport and QoL all had acceptable values. There was a positive, linear relationship between the Short-Form 12 Physical Component Summary and the KOOS subscales which indicated good evidence of convergent validity. These associations were also seen when the cohort was separated in medial and lateral UKA.

CONCLUSION

Two of the 5 KOOS subscales (KOOS Sport and KOOS QoL) were considered adequate in measuring outcomes, as well as reliability. The KOOS ADL had borderline values; however, it had adequate infit and outfit values. The KOOS Pain and Symptom score performed poorly in this analysis. For documenting outcomes following UKA, this study supports the use of KOOS ADL, Sport, and QoL.

The relationship between foot and ankle joint flexibility measures and barefoot plantar pressures in healthy older adults: a cross-sectional study

BACKGROUND

Restriction in foot and ankle joint range of motion, such as an ankle equinus, has been associated with increased plantar pressure and its complications. However, previous research is limited by its scope of measures and study populations. The aim of this study was to investigate the relationship between foot and ankle joint range of motion on barefoot plantar pressures during walking in healthy older adults.

METHODS

This cross-sectional study recruited 49 older adults. Participants underwent measures of foot (first metatarsophalangeal dorsiflexion range of motion, and navicular drop and drift) and ankle joint range of motion, foot posture, body mass index, and plantar pressure during barefoot walking. Spearman Rank Order Correlations were used to explore the relationship between foot and ankle measures, body mass index, and plantar pressure, with significant correlations explored in a hierarchical regression analysis. A Mann-Whitney U test was performed to compare plantar pressure values between those with and without ankle equinus per region of the foot.

RESULTS

Mean (SD) age and BMI were 72.4 years (5.2) and 29.8 kg/m² (5.9) respectively. A total of 32 of the 49 participants (65%) identified as female sex. Mean (SD) ankle joint range of motion was 32.7 (6.4) degrees with 17/49 (34.7%) participants classified as having an ankle equinus (defined as < 30 degrees of ankle joint dorsiflexion range of motion). We found that an ankle equinus predicted a statistically significant amount of peak forefoot plantar pressure (p = 0.03). Participants with an ankle equinus displayed significantly higher forefoot peak pressure 677.8 kPa (589.9 to 810.4) compared to those with no equinus 565.58 kPa (447.3 to 651.2), p = 0.02. A statistically significant correlation was found between body mass index and midfoot peak pressure (p < 0.01) and pressure-time integral (p < 0.01). No other significant correlations were found.

CONCLUSION

Clinicians should consider screening for an ankle equinus and body mass index as a simple way to identify which healthy older adults may be at risk of pressure-related complications in the mid- and forefoot.

Foot Assessment Clinical Scales in Charcot-Marie-Tooth Patients: A Scoping Review

Introduction

Charcot-Marie-Tooth disease (CMT) is a slow and progressive peripheral motor sensory neuropathy frequently associated with the cavo-varus foot deformity. We conducted a scoping review on the clinical scales used to assess foot deviations in CMT patients and analyzed their metric properties.

Evidence Acquisition

A first search was conducted to retrieve all scales used to assess foot characteristics in CMT patients from the Medline, Web of Science, Google Scholar, Cochrane, and PEDro databases. A second search was conducted to include all studies that evaluated the metric properties of such identified scales from the same databases. We followed the methodologic guidelines specific for scoping reviews and used the PICO framework to set the eligibility criteria. Two independent investigators screened all papers.

Evidence Synthesis

The first search found 724 papers. Of these, 41 were included, using six different scales: “Foot Posture Index” (FPI), “Foot Function Index”, “Maryland Foot Score”, “American Orthopedic Foot & Ankle Society's Hindfoot Evaluation Scale”, “Foot Health Status Questionnaire”, Wicart-Seringe grade. The second search produced 259 papers. Of these, 49 regarding the metric properties of these scales were included. We presented and analyzed the properties of all identified scales in terms of developmental history, clinical characteristics (domains, items, scores), metric characteristics (uni-dimensionality, inter- and intra-rater reliability, concurrent validity, responsiveness), and operational characteristics (normative values, manual availability, learning time and assessors' characteristics).

Conclusions

Our results suggested the adoption of the six-item version of the FPI scale (FPI-6) for foot assessment in the CMT population, with scoring provided by Rasch Analysis. This scale has demonstrated high applicability in different cohorts after a short training period for clinicians, along with good psychometric properties. FPI-6 can help health professionals to assess foot deformity in CMT patients over the years.

Effect of low back pain on clinical-functional factors and its associated potential risk of chronicity in adolescent dancers of classical ballet: cross-sectional study

BACKGROUND

Low back pain (LBP) is a common symptom in classical ballet dancers, which can limit their daily activities and dance training routines. The purpose of the study was to verify the association and comparison of clinical-functional outcomes (spine flexibility and foot posture) between different levels of intensity low back pain in adolescents of classical ballet and the potential risk of chronicity using the STarT back tool.

METHODS

Cross-sectional study.

PARTICIPANTS

78 adolescent girls who practice classical ballet were evaluated and divided into groups according to level of low back pain: mild (n = 21), moderate (n = 17), and high (n = 20), and a control group (n = 20).

MAIN OUTCOME MEASURES

Pain, flexibility of the spine (thoracic and lumbosacral), risk of chronicity for low back pain, and foot posture were assessed using the visual analogue scale, clinical tests, STarT back screening tool (SBST) questionnaire, and foot posture index (FPI), respectively.

RESULTS

Dancers with high-intensity low back pain showed a potential risk of chronicity by the SBST. The spine pain intensity was not different considering thoracic and lumbosacral flexibility in the sagittal plane, but was different with greater supine FPI when compared to control dancers. Mild low back pain was associated with greater supine FPI. The SBST score was associated with higher exposure time-frequency and time of dancing.

CONCLUSION

Adolescents of classical ballet with high-intensity low back pain showed a potential risk of chronicity by the SBST. The level of intensity low back pain did not influence the clinical-functional aspects of spine flexibility in the sagittal plane, but the level of intensity moderate pain promoted changes in foot posture (more supinated). The potential risk of chronicity using the SBST was also associated with higher exposure time-frequency and time of dancing, in adolescents of classical ballet.

Spatiotemporal parameters and gait variability in people with psoriatic arthritis (PsA): a cross-sectional study

Background

Foot involvement is a major manifestation of psoriatic arthritis (PsA) and can lead to severe levels of foot pain and disability and impaired functional mobility and quality of life. Gait spatiotemporal parameters (STPs) and gait variability, used as a clinical index of gait stability, have been associated with several adverse health outcomes, including risk of falling, functional decline, and mortality in a wide range of populations. Previous studies showed some alterations in STPs in people with PsA. However, gait variability and the relationships between STPs, gait variability and self-reported foot pain and disability have never been studied in these populations. Body-worn inertial measurement units (IMUs) are gaining interest in measuring gait parameters in clinical settings.

Objectives

To assess STPs and gait variability in people with PsA using IMUs, to explore their relationship with self-reported foot pain and function and to investigate the feasibility of using IMUs to discriminate patient groups based on gait speed-critical values.

Methods

Twenty-one participants with PsA (age: 53.9 ± 8.9 yrs.; median disease duration: 6 yrs) and 21 age- and sex-matched healthy participants (age 54.23 ± 9.3 yrs) were recruited. All the participants performed three 10-m walk test trials at their comfortable speed. STPs and gait variability were recorded and calculated using six body-worn IMUs and Mobility Lab software (APDM®). Foot pain and disability were assessed in participants with PsA using the foot function index (FFI).

Results

Cadence, gait speed, stride length, and swing phase were significantly lower, while double support was significantly higher, in the PsA group (p < 0.006). Strong correlations between STPs and the FFI total score were demonstrated (|r| > 0.57, p < 0.006). Gait variability was significantly increased in the PsA group, but it was not correlated with foot pain or function (p < 0.006). Using the IMUs, three subgroups of participants with PsA with clinically meaningful differences in self-reported foot pain and disability were discriminated.

Conclusion

STPs were significantly altered in participants with PsA, which could be associated with self-reported foot pain and disability. Future studies are required to confirm the increased gait variability highlighted in this study and its potential underlying causes. Using IMUs has been useful to objectively assess foot function in people with PsA.

Trial registration

ClinicalTrials.gov, NCT05075343, Retrospectively registered on 29 September 2021.

Is there a relationship between lower-extremity injuries and foot postures in professional football players? A prospective cohort study

BACKGROUND

Lower extremity injuries are an ongoing concern for professional football players. This study aims to evaluate the relationship between foot posture and lower extremity injuries in professional football players.

METHOD

In this prospective cohort study, 420 male players of the Iran Premium football league were evaluated during the 2015-2016 season. The players were assessed for their foot types based on optical and static foot scans and foot posture index (FPI). The trained club physicians recorded all injuries during the season.

RESULT

The analyzed data of 244 players showed the highest rate of lower extremity injury in hamstrings, ankle, and groin, respectively. These injuries led to 46% of time loss. The probability of hamstrings injuries was higher among pronated players based on static, optic, FPI, and visual examination, 2.1, 1.8, 1.8, and 2.3, respectively. Medial Collateral Ligament (MCL) injuries were associated with subtalar joint abnormality defined by visual observation. An increased relative risk of leading-to-absence injuries among the flat foot group was significant based on optic scanning, FPI, and visual observation.

CONCLUSION

Abnormal foot postures in professional football players may increase the risk of hamstring and MCL injuries and time loss due to lower extremity injuries.

Comparison of ankle force, mobility, flexibility, and plantar pressure values in athletes according to foot posture index

Objectives

This study aims to compare ankle force, mobility, flexibility, and plantar pressure distribution of athletes according to foot posture index (FPI).

Patients and methods

Between September 2016 and May 2018, a total of 70 volunteer male athletes (mean age: 21.1±2.3 years; range, 18 to 25 years) were included. The athletes were divided into three groups according to their FPI as follows: having supinated feet (Group 1, n=16), neutral/normal feet (Group 2, n=36), or pronated feet (Group 3, n=18). Ankle range of motion (ROM), muscle flexibility, ankle joint strength, and plantar pressure distribution were measured.

Results

There were significant differences among the three groups in both right and left ankle dorsiflexion ROM (p=0.009 and p=0.003, respectively). Group 1 had significantly smaller dorsiflexion ROM than the other groups. Group 1 also showed significantly less flexibility in the gastrocnemius and soleus muscles than the other foot posture groups. Groups 2 and 3 exhibited significant differences in the maximum torque (p=0.018), maximum work (p=0.008), and total work (p=0.008) of the right plantar flexor muscles at 60°/sec angular velocity. Peak pressure measurements of the right foot were higher in Group 1, compared to Groups 2 and 3 (p<0.001).

Conclusion

The results of this study may help to enhance athletic performance by providing a guide for designing training programs appropriate for athletes with different foot types to address their specific muscle flexibility and strength deficiencies.

The Association Between Foot Structure and Foot Kinematics During Slow Running

BACKGROUND

Clinicians routinely assess foot posture as part of their assessment and management of foot pathologies. Flat or high-arched foot postures have been linked to kinematic deviations and increased risk of foot injuries. The Foot Posture Index (FPI) is a valid clinical tool used to classify feet into high-arched, normal-arched, and flat foot groups and predicts foot function during walking well. Walking and running are distinct locomotion styles, and studies have not been performed to correlate FPI to foot function during running. This study aims to investigate the association of FPI scores to foot kinematics during running. The results will further inform clinicians who perform static assessment of feet of individuals who are runners.

METHODS

Sixty-nine participants had their feet assessed using the FPI scoring system. Based on these scores, the feet were categorized as flat foot, normal-arched, and high-arched. Rearfoot eversion and forefoot dorsiflexion (arch flattening) of the foot were analysed during slow running between 1.4 and 2.2 m/sec. The Pearson correlation was used to analyse the FPI scores on an interval scale, with Cohen's d used to report effect size. One-way analysis of variance and a Bonferroni post hoc test was used to analyze data by category. Level of significance was set at P < .05.

RESULTS

Thirty-four flat feet, 26 normal-arched feet, and nine high-arched feet were analyzed. The FPI scores correlated significantly with rearfoot eversion (moderate effect size) and forefoot dorsiflexion (low effect size). Rearfoot eversion was greatest in the flat foot, followed by the normal-arched foot and the high-arched foot. Forefoot dorsiflexion was significantly higher in the flat foot compared with the high-arched group.

CONCLUSIONS

Foot Posture Index scores are positively correlated with rearfoot eversion and forefoot dorsiflexion during running. Clinicians can use this information to aid their foot assessment and management of individuals who are runners.

Risk Factors Influencing the Incidence of Ankle Sprain Among Elite Football and Basketball Players: A Prospective Study

Introduction. The objective of the present study was to investigate whether certain intrinsic factors (foot hyperpronation, generalized joint laxity) and clinical tests (anterior drawer and talar tilt tests, single-leg balance test and star excursion balance test, ankle and first metatarsophalangeal range of motion) could predict the incidence of lateral ankle sprains among elite football and basketball players during a full year. Method. In a prospective cohort study, 106 elite basketball and football players were recruited. During the preseason period, players underwent baseline measurements. Team physicians in following year reported occurrence of new ankle sprains. Results. Ankle sprain was more frequent among basketball players (P = .01). The history of recurrent (P = .001) and acute ankle sprain (P = .01) and each 5-year increase in age (P = .039) were predictive factors for ankle sprain. No evidence for relationship between other risk factors and occurrence of ankle sprain were achieved. Conclusion. In our study, the history of recurrent and acute ankle sprain was the strongest predictor for ankle injuries. Considering the limitations of this study, it seems mandatory to conduct more prospective studies with a larger sample size and longer follow-up period.Levels of Evidence: Level II: Prognostic.

Long-term training on sand changes lower limb muscle activities during running in runners with over-pronated feet

BACKGROUND

Running on sand could be a promising exercise intervention for the treatment of over-pronated feet. However, there is a lack of knowledge about the effects of running on sand on muscle activities. Therefore, this study aims to evaluate the long-term effects of running on sand on the activities of selected lower limb muscles in individuals with OPF compared with healthy controls.

METHODS

Sixty recreational adult male runners with over-pronated feet (foot posture index > 10) were divided into two equal groups (intervention and control). Participants ran barefoot at a pre-defined speed (⁓3.3 m/s) over level stable ground both before and after long-term training on the sand. Muscle activities were recorded using a surface bipolar electromyography system.

RESULTS

For the intervention group, we found a reduced foot posture index (p < 0.001; d = 2.00) and significant group-by-time interactions for gluteus medius activity during the mid-stance phase (p < 0.028; d = 0.59). Significantly higher gluteus medius activity (p = 0.028, d = 0.569) was found during the post-test. We also observed significant group-by-time interactions for medial gastrocnemius activity during the push-off phase (p < 0.041; d = 0.54). Significantly larger medial gastrocnemius activity (p = 0.041; d = 0.636) was found during the post-test compared to the pre-test.

CONCLUSIONS

Long-term running on sand resulted in reduced pronation, increased medial gastrocnemius activity, and improved frontal plane pelvic stability due to higher gluteus medius activity.

TRIAL REGISTRATION

IRCT20191211045704N1. Registered 25 February 2020. Retrospectively registered.

Transfer of distal peroneus longus tendon to tibialis anterior by retrograde fixation to treat spastic equinovarus foot in adults: Surgical Technique and Preliminary Results

We describe a retrograde transfer of the distal tendon of the peroneus longus (PL) onto the tibialis anterior (TA) tendon to treat spastic equinovarus foot (SEVF) in adults. The fact that the distal tendon insertions of the PL and TA are a mirror image makes them antagonists. The aim is to divert the distal tendon in front the inactive distal PL tendon, by fixing to the TA in the middle third of the lower leg. This transforms it into a dorsiflexor and reinforces its eversion ability. The suture level helps to avoid skin impingement when wearing shoes, and the complications inherent to transosseous fixation. In a preliminary case series of 10 patients, we found no complications at a mean follow-up of 4.7 years. The Foot Posture Index-6 improved by an average of 2.4 points. Four patients had regained active dorsiflexion. All patients reduced their use of orthotics. All patients improved according to Goal Attainment Scaling.

A Retrospective Study of Foot Biomechanics and Injury History in Varsity Football Athletes at the U.S. Naval Academy

INTRODUCTION

The six-item Foot Posture Index (FPI-6) was previously developed as an assessment tool to measure the posture of the foot across multiple segments and planes. It was derived from a criterion-based observational assessment of six components of each foot during static standing. The association between abnormal foot posture and musculoskeletal injuries remains unclear and is in of need further exploration.

HYPOTHESIS/PURPOSE

The purpose of this study was to assess the association between foot biomechanics and self-reported history of musculoskeletal pain or injury.

STUDY DESIGN

Retrospective, cross-sectional study of collegiate football players at the U.S. Naval Academy.

MATERIALS AND METHODS

For each athlete, data were recorded on height, weight, self-reported history of pain or injury, and foot posture, which was measured using a FPI-6 with each item measuring the degree of pronation/supination. The primary outcome was each athlete's maximum deviation from neutral posture across the six-item index (FPImax). The prespecified primary analysis used generalized linear models to measure the association between FPImax and self-report history of pain or injury. Exploratory analyses measured the association using penalized regression (L1-norm) and a type of tree-based ensemble known as extreme gradient boosting (XGBoost).

RESULTS

Data were collected on 101 athletes, 99 of whom had sufficient body mass index (BMI) data to be included for analysis. Among the 99 athletes, higher FPImax was associated with a prior history of musculoskeletal pain (odds ratio [OR] 1.15, 95% confidence interval [CI] 0.97 to 1.35), although the sample size was too small for the association to be significant with 95% CI (P = .107). FPImax was not associated with a history of knee injury/pain (OR 0.98, 95% CI 0.83 to 1.15, P = .792), nor with a history of ankle/foot injury or pain (OR 1.04, 95% CI 0.90 to 1.21, P = .599). From the L1-penalized model, the FPI components with the strongest linear associations were the L6, R2, R1-squared, and FPImax. From the XGBoost model, the most important variables were FPItotal, BMI, R1, and R2.

CONCLUSIONS

The U.S. Naval Academy football players whose foot postures deviated from neutral were more likely to have reported a previous history of musculoskeletal pain. However, this deviation from normal was not strongly associated with a specific history of pain or injury to the knee, ankle, or foot.

CLINICAL RELEVANCE

The information ascertained from this study could be used to better inform clinicians about the value of the FPI in predicting or mitigating injuries for varsity football athletes.

Chronic Plantar Heel Pain Is Principally Associated With Waist Girth (Systemic) and Pain (Central) Factors, Not Foot Factors: A Case-Control Study

OBJECTIVE

To determine the independent associations of potential clinical, symptom, physical activity, and psychological factors with chronic plantar heel pain.

DESIGN

Case-control.

METHODS

We investigated associations by comparing 220 participants with chronic (more than 3 months in duration) plantar heel pain to 100 age- and sex-matched controls, who were recruited randomly from the electoral roll. Exposures measured were waist girth, body mass index, body composition, clinical measures of foot and leg function, physical activity via accelerometry, depression and pain catastrophizing, symptoms of prolonged morning stiffness anywhere in the body, and multisite pain. Data were analyzed using multivariable conditional logistic regression.

RESULTS

Waist girth (centimeters) (odds ratio [OR] = 1.06; 95% confidence interval [CI]: 1.03, 1.09), ankle plantar flexor strength (kilograms) (OR = 0.98; 95% CI: 0.97, 0.99), pain at multiple sites (pain at 1 other site: OR = 2.76; 95% CI: 1.29, 5.91; pain at 4 or more other sites: OR = 10.45; 95% CI: 3.66, 29.81), and pain catastrophizing status (none, some, or catastrophizer) (some: OR = 2.91; 95% CI: 1.33, 6.37; catastrophizer: OR = 6.79; 95% CI: 1.91, 24.11) were independently associated with chronic plantar heel pain. There were univariable but not independent associations with morning stiffness, first metatarsophalangeal joint extension range of motion, depression, and body mass index. There were no significant associations with physical activity or body composition (bioelectrical impedance analysis).

CONCLUSION

Waist girth, ankle plantar flexor strength, multisite pain, and pain catastrophizing, but not foot-specific factors, were independently associated with chronic plantar heel pain. Of these 4 factors, 3 (waist girth, multisite pain, and pain catastrophizing) were central or systemic associations. J Orthop Sports Phys Ther 2021;51(9):449-458. Epub 7 May 2021. doi:10.2519/jospt.2021.10018.

Effects of taping techniques on arch deformation in adults with pes planus: A meta-analysis

Objective

To investigate effects of taping techniques on arch deformation in adults with pes planus.

Methods

The following databases were searched up to March 2020, including Web of Science, Pubmed, EBSCO, CNKI and Cochrane Library. Heterogeneity and publication bias were assessed by I² index and funnel plots, respectively. In addition, Cochrane scale was used to evaluate the quality of research.

Results

Navicular height for three antipronation taping techniques significantly increased immediately post tape compared with baseline (mean difference = 4.86 mm, 95% CI = 2.86–6.87 mm, Z = 4.75, p < 0.001). The highest increase was observed in Augmented low-Dye (ALD). Modified low-Dye (MLD) was second only to ALD (p<0.001). Navicular height after walking for 10 min was much higher than baseline (p<0.001), with MLD decreased smaller than ALD.

Conclusions

ALD was the most effective taping technique for controlling foot arch collapse immediately post tape compared with baseline, followed by MLD. By contrast, MLD could possibly performed better than ALD in maintaining immediate navicular height after walking for 10 min. Low-Dye could make resting calcaneal stance position closer to neutral position. Although positive effects of Navicular sling, low-Dye and Double X taping interventions were observed, they could not maintain this immediate navicular height effect after a period of higher intensity weight-bearing exercise.

A Rasch analysis of the self-administered Foot Health Assessment Instrument (S-FHAI)

Background

Reliable and valid measurement is the foundation of evidence-based practice. The self-administered Foot Health Assessment Instrument (S-FHAI) was recently developed to measure patients’ evaluations of their own foot health. Evidence regarding the psychometric properties of the S-FHAI is limited. The aim of this study was to investigate those properties by using a Rasch analysis.

Methods

This methodological study analysed secondary data that was collected from nurses (n = 411) in 2015. The psychometric properties of the S-FHAI were evaluated using the Rasch model. Unidimensionality was analysed first, followed by item functioning, person misfit and differential item functioning (DIF).

Results

The S-FHAI demonstrated evidence of unidimensionality, with an acceptable item fit according to the Rasch model. Person fit and person separation were low, however, indicating restricted separation among different respondents. Item separation was high, demonstrating clear discrimination between the items. No DIF was detected in relation to gender, but significant DIF was demonstrated in relation to age for 6 of the 25 items.

Conclusions

The S-FHAI has potential for use in investigating self-reported foot health. The Rasch analysis revealed that the psychometric properties of the instrument were acceptable, although some issues should be addressed to improve the scale. In future, it may be beneficial to analyse the sensitivity of the items and to test the S-FHAI in more diverse patient populations.

Effects of Typical Athletic Shoes on Postural Balance According to Foot Type

BACKGROUND

The effects of shoes and foot type on balance are unclear. We aimed to investigate the differences between static and dynamic balance among three foot types and the changes in postural balance while wearing typical athletic shoes.

METHODS

Based on the Foot Posture Index, the feet of 39 participants were classified as pronated, neutral, or supinated by a physiatrist. Static and dynamic balance function were assessed by center of gravity (COG) sway velocity with eyes open and eyes closed and a modified Star Excursion Balance Test in a random order with participants either barefoot or wearing shoes.

RESULTS

The COG sway velocity was significantly higher in the supinated foot group than in the neutral foot group (barefoot: eyes open, P = .004, eyes closed, P = .001). Normalized composite reach distance (NCRD) was significantly lower in the pronated and supinated foot groups (barefoot: P = .039, P = .008; shoes: P = .018, P = .018). In all three foot type groups, COG sway velocity was significantly decreased (P < .05) and NCRD was significantly increased (P < .05) while wearing typical athletic shoes.

CONCLUSIONS

The medial longitudinal arch of the foot affects postural balance. Typical athletic shoes improve postural balance regardless of foot type. However, the pronated and supinated foot groups still had lower dynamic postural balance compared with the neutral foot group, even when wearing athletic shoes. People with pronated and supinated feet may need additional interventions, such as foot orthoses or balance training.

Foot deformities in patients with diabetic mellitus (with and without peripheral neuropathy)

BACKGROUND

Diabetic peripheral neuropathy (DPN) is one of the most common complications in diabetes mellitus. It is the disorder that most commonly affects the feet of people with diabetes. The aim of the present study is to determine the relationship between DPN and the presence of deformities in the foot.

MATERIAL AND METHODS

A descriptive observational study was conducted of 111 patients diagnosed with Diabetes Mellitus (DM) type 1 or 2. All participants were aged at least 18 years and were previously informed in detail about the aims and procedures of the study.

RESULTS

Regarding the presence of DPN, the only significant relationships were found for the right foot with the deformity of the second toe (claw, hammer or mallet) (p = 0.017, OR 0.29 [0.10-0.83]) and for the left foot with the deformity of the second toe (p = 0.048; OR: 0.37 [0.14-1.01]), third toe (p = 0.012; OR: 0.29 [0.11-0.79]) and the presence of hallux extensus (p = 0.05; OR: 8.27 [1.05-64.98]).

CONCLUSIONS

A significant number of foot deformities were observed among these patients with DM, regardless of the presence of DPN. These deformities should be carefully evaluated in order to determine the most appropriate treatment at an early stage, which will reduce the risk of ulceration. Although it should be use with caution to be transferrable to the general population with peripheral neuropathy.

Clinical measures of foot posture and ankle joint dorsiflexion do not differ in adults with and without plantar heel pain

Foot posture and ankle joint dorsiflexion have long been proposed to be risk factors for plantar heel pain, however body mass may be a confounder when investigating these factors. The aim of this study was to determine if clinical measures of foot posture and ankle joint dorsiflexion differ in adults with and without plantar heel pain after accounting for body mass. This was a cross-sectional observational study that compared 50 participants with plantar heel pain to 25 control participants without plantar heel pain who were matched for age, sex and body mass index. Foot posture was assessed using the Foot Posture Index and the Arch Index. Ankle joint dorsiflexion was assessed with a weightbearing lunge test with the knee extended and with the knee flexed. No significant differences (P < 0.05) were found between the groups for foot posture, whether measured with the Foot Posture Index or the Arch Index. Similarly, no significant differences were found in the weightbearing lunge test whether measured with the knee extended or with the knee flexed. Clinical measures of foot posture and ankle joint dorsiflexion do not differ in adults with and without plantar heel pain when body mass is accounted for. Therefore, clinicians should not focus exclusively on foot posture and ankle dorsiflexion and ignore the contribution of overweight or obesity.

Morphological and Postural Changes in the Foot during Pregnancy and Puerperium: A Longitudinal Study

The aim of this study is to observe the morphological and postural changes to the foot that take place during pregnancy and the puerperium. Method: In this descriptive, observational, longitudinal study, we analysed 23 pregnant women, with particular attention to morphological and postural aspects of the foot, at three time points during and after pregnancy: in weeks 9-13 of gestation, weeks 32-35 of gestation and weeks 4-6 after delivery. The parameters considered were changes in foot length, the Foot Posture Index (FPI) and the Hernández Corvo Index, which were analysed using a pedigraph and taking into account the Body Mass Index (BMI). The same procedure was conducted in each review. Results: The statistical analyses obtained for each foot did not differ significantly between the three measurement times. A pronator-type footprint was most frequently observed during the third trimester of pregnancy; it was predominantly neutral during the postpartum period. Statistically significant differences between the measurement times were obtained in the right foot for cavus vs. neutral foot type (between the first and third trimesters and also between the first trimester and the puerperium) (in both cases, p < 0.0001). Conclusions: Foot length increases in the third trimester and returns to normal in the puerperium. According to FPI findings, the third trimester of pregnancy is characterised by pronation, while the posture returns to neutrality during the postpartum period. During pregnancy, the plantar arch flattens, and this persists during the puerperium. The incidence of cavus foot increases significantly in the third trimester and in the puerperium.

Fatigue in Children with Pronated Feet After Aerobic Exercises

BACKGROUND

Sports have a strong influence on current society. Foot posture has been postulated to be a risk factor for overuse injuries; however, the link between foot posture and injuries is unclear. This study aimed to determine whether children with pronated feet become more fatigued after participating in sports tests than those with normal feet.

METHODS

One hundred five children aged 10 to 12 years (mean ± SD age, 10.46 ± 0.78 years) participated in the sports tests, which were aerobic-type resistance exercises with six stations at which each child remained for 30 sec. The posture of the foot was evaluated via the Foot Posture Index and the plantar footprint via the arch index and the Clarke angle before and after aerobic-type resistance exercises. Perceived tiredness was evaluated with the Pictorial Children's Effort Rating Table (PCERT) and whether there was pain during or after physical activity.

RESULTS

The variables used to measure foot posture and the plantar arch changed more in the pronated feet, suggesting that the feet undergo more pronation after physical exercise. The neutral feet obtained a mean ± SD PCERT score of 5.46 ± 1.89 and the pronated feet a score of 7.60 ± 1.92.

CONCLUSIONS

Children with pronated feet showed more fatigue and foot pain during and/or after physical exercise than those with neutral feet. Foot type could be responsible for the lack of enthusiasm of children toward undertaking healthy activities, and this problem might be solved via appropriate orthopedic treatment.

Gluteus medius muscle activity during gait in people with and without chronic nonspecific low back pain: A case control study

BACKGROUND

Research investigating differences in gluteus medius muscle activity in those with and without chronic nonspecific low back pain is both limited and conflicting. Additionally, in these populations the relationship between gluteus medius muscle activity, foot type, and transversus abdominis muscle thickness is unclear.

RESEARCH QUESTION

We aimed to investigate gluteus medius muscle activity during gait in those with and without chronic nonspecific low back pain. Secondarily, we aimed to explore the association between gluteus medius muscle activity, foot type, and transversus abdominis muscle thickness within groups.

METHODS

This case control study recruited 30 people with and 30 people without chronic nonspecific low back pain and matched participants by age (±5 years), sex, and body mass index (±2 BMI units). Gluteus medius muscle activity was measured with surface electromyography during walking gait, with foot type and transversus abdominis muscle thickness measured with the Foot Posture Index and ultrasound respectively. The Mann-Whitney U test was used to investigate differences in gluteus medius muscle activity between groups. Spearman rank order correlation was performed to explore the association between gluteus medius muscle activity, foot type, and transversus abdominis thickness within each group. A linear regression was used to analyse significant correlations (P < 0.05).

RESULTS

We found no significant differences in gluteus medius muscle activity between groups. However, there was a moderate correlation between the Foot Posture Index score and gluteus medius peak amplitude (P = 0.04) for those with mild to moderate chronic nonspecific low back pain.

SIGNIFICANCE

Clinicians should be aware that patients with mild to moderate chronic nonspecific low back pain may not demonstrate significant differences in gluteus medius muscle activity compared to those without back pain. Additionally, higher peak gluteus medius muscle activity is likely to occur in people with mild to moderate chronic nonspecific low back pain and planus feet.

Kinesiotaping Techniques to Alter Static Load in Patients With Foot Pronation

Objective

This study aimed to assess the effect of kinesio tape (KT) application on foot pronation using the laser postural alignment system.

Methods

Twenty participants (10 females and 10 males, mean age 19.7 ± 1.2 years) with foot pronation were included in the study. The laser line projected on the participant by the laser postural alignment system showed the joint load carrying line. The location of the joint load carrying line was assessed during barefoot static standing with one foot on the force plate before KT application, immediately after application, then 24 and 48 hours later. Displacement of the load-carrying line was measured using a ruler placed tangentially to the patella and ankle joint at the level of the joint line. Weight bearing on the barefoot was assessed before KT application, immediately after, then 24 and 48 hours later.

Results

Weight bearing was not significantly changed after KT application. The load-carrying line measured using KT did not notably move with KT versus without KT in the ankle joint. Immediately after KT application, significant lateral knee joint movement was measured, but this change was not importantly 24 and 48 hours later.

Conclusion

KT was not altered in changing weight bearing or moving the lower extremity load-carrying line in people with foot pronation. KT of the foot can amplify sensory input and improve perceived comfort; therefore, it can be used with an orthotic insole in footwear.

Plantar pressure distribution and wearing characteristics of three forefoot offloading shoes in healthy adult subjects

Forefoot offloading shoes are used to reduce pressure on specific regions of the foot. Aim of the pressure reduction is to aid healing of the soft and bony tissues and prevent complications by treating foot disorders. A great variety of forefoot offloading shoes are available. In a first step to investigate the appropriate use of these footwear in orthopedic settings, we studied plantar pressure distribution and wearing characteristics of three forefoot offloading shoes namely the Mailand, OrthoWedge and Podalux in a healthy population. Twenty subjects walked in a randomized order wearing three forefoot offloading shoes and a reference shoe for six minutes. The Pedar system was used to measure the pressure in 7 regions. Peak pressure and pressure time integral were analyzed as measures of pressure distribution. Furthermore, wearing characteristics were addressed using a Numeric Rating Scale. Pressure distribution and wearing characteristics of the forefoot offloading shoes were compared to a reference shoe. The Mailand and OrthoWedge shoes significantly reduced peak pressure with more than 80% under the hallux and more than 45% under MTH1 (p<.001). The Podalux did not show significant peak pressure reduction under the forefoot compared to the reference shoe. Under the lesser toes, the MTH4-5 region and heel region the Podalux shoe showed even a significant increase in peak pressure (p=.001). Looking at wearing characteristics, the Podalux and reference shoe scored significantly better than the other two forefoot offloading shoes (p<.01). In this study the differences between different forefoot offloading shoes was assessed. The Mailand and OrthoWedge shoes gave the best pressure reduction in the forefoot but are less comfortable in use. The Podalux rocker shoe showed opposite results. Next step is a patient study to compare our results in a patient population.

Foot Core Training to Prevent Running-Related Injuries: A Survival Analysis of a Single-Blind, Randomized Controlled Trial

BACKGROUND

Running-related injuries (RRIs) are a pervasive menace that can interrupt or end the participation of recreational runners in this healthy physical activity. To date, no satisfactory treatment has been developed to prevent RRIs.

PURPOSE

To investigate the efficacy of a novel foot core strengthening protocol based on a ground-up approach to reduce the incidence of RRIs in recreational long-distance runners over the course of a 1-year follow-up.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

The participants, 118 runners, were assessed at baseline and randomly allocated to either an intervention group (n = 57) or a control group (n = 61). The intervention group received an 8-week training course focused on the foot-ankle muscles, followed by remotely supervised training thereafter. Assessments consisted of 3 separate biomechanical evaluations of foot strength and foot posture and a weekly report on each participant's running distance, pace, and injury incidence over 12 months.

RESULTS

The control group participants were 2.42 times (95% CI, 1.98-3.62) more likely to experience an RRI within the 12-month study period than participants in the intervention group (P = .035). Time to injury was significantly correlated with Foot Posture Index (P = .031; r = 0.41) and foot strength gain (P = .044; r = 0.45) scores. This foot exercise program showed evidence of effective RRI risk reduction in recreational runners at 4 to 8 months of training.

CONCLUSION

Recreational runners randomized to the new foot core strengthening protocol had a 2.42-fold lower rate of RRIs compared with the control group. Further studies are recommended to better understand the underlying biomechanical mechanisms of injury, types of injuries, and subgroups of runners who might benefit maximally.

REGISTRATION

NCT02306148 (ClinicalTrials.gov identifier).

An exploratory study investigating the effect of foot type and foot orthoses on gluteus medius muscle activity

Background

Abnormal gluteus medius muscle activity is associated with a number of musculoskeletal conditions. Research investigating the effect of foot type and foot orthoses on gluteus medius muscle activity is both conflicting and limited. The primary aim was to investigate the relationship between foot type and gluteus medius muscle activity during shod walking. The secondary aims of this study were to explore the effect and amount of usage of a pair of unmodified prefabricated foot orthoses on gluteus medius muscle activity during shod walking.

Methods

Foot type was determined using the foot posture index and gluteus medius muscle activity was measured with surface electromyography in 50 healthy adults during shod walking. Participants were then fitted with prefabricated foot orthoses and required to return after 4 weeks. Pearson’s correlation and one-way ANOVA were used to determine effect of foot type. Paired t-tests and ANCOVA were used to determine effect of foot orthoses.

Results

Participants with a cavus foot type demonstrated significantly more gluteus medius mean (p = 0.04) and peak amplitude (p = 0.01), and a greater range in amplitude (p = 0.01) compared to participants with a neutral foot type. Compared to a planus foot type, participants with a cavus foot type demonstrated significantly larger mean (p = 0.02) and peak amplitude (p = 0.01), and a greater range in amplitude (p = 0.01). Prefabricated foot orthoses did not change the gluteus medius muscle activity.

Conclusion

When assessing healthy adults with a cavus foot type, clinicians and researchers should be aware that these participants may display higher levels of gluteus medius muscle activity during gait compared to neutral and planus type feet. Additionally, clinicians and researchers should be aware that the type of prefabricated foot orthoses used did not change gluteus medius muscle activity over 4 weeks. Future research should aim to explore this relationship between foot type and gluteus medius muscle activity in larger sample sizes, consider the potential role of other lower extremity muscles and biomechanical variables, and investigate if these findings also occur in people with pathology.

The effect of modifying foot progression angle on the knee loading parameters in healthy participants with different static foot postures

BACKGROUND

Studies have found that toe-in gait reduced the peak knee adduction moment (KAM) during early stance, while toe-out gait reduced the peak KAM during late stance. However, some other studies found that toe-in or toe-out gait could reduce the KAM throughout stance phase. There is still a divergence of opinion on the use of toe-in or toe-out gait for reducing the KAM.

RESEARCH QUESTION

This study aimed to investigate whether static foot posture affected participants' biomechanical responses to three self-selected foot progression angles (FPA): neutral, toe-out and toe-in.

METHODS

Twenty-seven healthy participants were recruited for this FPA gait modification experiment and classified into three groups: neutral (n = 8), supination (n = 9) and pronation (n = 10), based on the Foot Posture Index (FPI). The kinematic and kinetic data were recorded with Vicon motion capture system and three force plates. The knee adduction moment and ankle eversion moment were calculated using an inverse dynamics model. The effect of the FPA modification on the knee loading parameters was analysed by the Friedman non-parametric test.

RESULTS

The KAM results in the neutral group showed that the toe-in gait modification reduced the first peak of the KAM (KAM1), while the KAM1 was increased in the supination group. The effect of the FPA modification on the KAM1 did not reach significance in the pronation group. The toe-out gait modification reduced the second peak (KAM2) regardless of the static posture.

SIGNIFICANCE

Different static foot postures were correlated with different peak KAM during the early stance phase due to FPA modification. These data suggest that the assessment of static foot posture provides a reference on how to offer adequate FPA modification for knee OA patients with different foot postures.

Hallux valgus severity, great toe pain, and plantar pressures during gait: A cross-sectional study of community-dwelling adults

BACKGROUND

Hallux valgus (HV) is a common disabling condition affecting 36% of adults aged 65 years and over. Identifying whether the severity of the deformity alters weight-bearing patterns during walking may assist clinicians optimize offloading interventions. Therefore, we examined how plantar pressure distributions during walking are affected by HV severity.

METHODS

Plantar pressures and maximum forces in ten regions of the foot were obtained from 120 participants (40 men, 80 women) aged ≥50 years using a pressure platform (RSscan® International, Olen, Belgium). HV severity was documented using a validated line-drawing instrument with participants separated into four groups: none (n = 30), mild (n = 30), moderate (n = 30) and severe (n = 30). Pressure and force values were compared across HV severity, stratified by the presence or absence of great toe pain.

RESULTS

Participants with severe HV were more likely to have great toe pain. More severe HV was associated with significant reductions in peak pressure and maximum force under the hallux but not at other sites of the foot. This association appeared strongest in those reporting great toe pain.

CONCLUSIONS

Greater HV severity is associated with great toe pain and reduced loading under the hallux when walking. These observed changes in plantar pressure and maximum force may reflect a pain avoidance mechanism.

Reliability of Different Clinical Techniques for Assessing Foot Posture

OBJECTIVE

The aim was to determine the interrater and intrarater reliability of navicular drop (NDP), navicular drift (NDT), and the Foot Posture Index-6 (FPI-6), and test-retest reliability of the static arch index (SAI) and dynamic arch index (DAI).

METHODS

Sixty healthy individuals were assessed for intrarater and test-retest reliability. From 60 participants, 30 individuals were assessed for interrater reliability. A digital caliper was used to measure NDP and NDT. Electronic pedography was used to calculate SAI and DAI. The FPI-6 was also performed. All assessments were performed on the dominant foot. The NDP, NDT, SAI, and DAI were repeated 3 times. The NDP and NDT were analyzed separately using both first measurement and the average, but the SAI and DAI were analyzed using only the average. The NDP, NDT, and FPI-6 were conducted by 2 raters to determine interrater reliability and were repeated by a single rater after 5 days from initial assessment to determine intrarater reliability. The SAI and DAI were also repeated after 5 days to determine test-retest reliability.

RESULTS

Intrarater intraclass correlation coefficients (ICCs) were 0.934 and 0.970 for NDP, 0.724 and 0.850 for NDT, and 0.945 for FPI. Interrater ICCs were 0.712 and 0.811 for NDP, 0.592 and 0.797 for NDT, and 0.575 for FPI. Test-retest ICCs of the SAI and DAI were 0.850 and 0.876, respectively.

CONCLUSION

Navicular drop is relatively more reliable than other traditional techniques. Also, the FPI-6 has excellent intrarater reliability, but only moderate interrater reliability. The results can provide clinicians and researchers with a reliable way to implement foot posture assessment.

Development and evaluation of a dual density insole for people standing for long periods of time at work

BACKGROUND

Appropriate footwear is important for those who stand for prolonged periods of time at work, enabling them to remain comfortable, healthy and safe. Preferences for different footwear cushioning or hardness are often person specific and one shoe or insole will not be the choice for all. The aim of this study was to develop a range of insole options to maintain comfort during long periods of standing at work and test insole material preferences in the workplace.

METHODS

The study consisted of two parts. Part one evaluated 9 insoles of the same geometry that varied in hardness under 2 different plantar regions (n = 34). Insole preference, plantar pressure and selected anthropometric foot measures were taken. Three insole designs based on the most preferred options were identified from this part. In part two, these three insoles were evaluated with 22 workers immediately after trying them on (1 min) and after a working day. Foot anthropometric measures and subjective questions concerning material hardness preferences and self-reported foot characteristics were used to investigate whether either had a relationship with insole preference.

RESULTS

Part one found insole preference predominantly varied according to material hardness under the medial arch rather than the heel/forefoot. Softer material under the heel and forefoot was associated with a reduction in peak pressures in these regions (p < 0.05). The most preferred insole had lower pressures under the hallux and first metatarsal phalangeal joint, and greater pressures and contact area under the medial midfoot (p < 0.05) compared to the least preferred insole. Height and foot anthropometrics were related to insole preference. In part two, under real world conditions, insole preference changed for 65% of participants between the immediate assessment (1 min) and after a whole workday, with dorsum height related to the latter (p < 0.05). Subjective questions for self-assessed arch height and footwear feel identified 66.7% of the insole preferences after 1 day at work, compared to 36% using immediate assessment of insole preference.

CONCLUSION

Preference for material hardness varies underneath the medial arch of the foot and is time dependent. Simple foot measures and questions about comfort can guide selection of preferred insoles.

Relationship between foot posture index and weight bearing computed tomography 3D biometrics to define foot alignment

BACKGROUND

The Foot Posture Index (FPI) was originally validated only against two dimensional radiographic imaging at the time of its inception since weight bearing three dimensional (3D) imaging did not exist. This technology is now widely available but it is not known if the FPI will continue to correlate well against it.

RESEARCH QUESTION

How does the clinical assessment tool of FPI correlate against 3D biometrics of foot alignment assessed on weight bearing computerised tomography (WBCT)?

METHODS

The FPI and 3D biometrics of 66 feet in 33 patients presenting to a single foot and ankle unit were assessed by two observers independently. All measurements were assessed for intra-rater and inter-rater reliability, and the association between the clinically assessed FPI and radiologically assessed 3D biometrics was identified.

RESULTS

The FPI demonstrated excellent intra-rater and good inter-rater reliability. All 3D biometric measures demonstrated excellent intra-rater and inter-rater reliability. A strong and significant correlation was identified between the FPI and 3D biometrics overall although subgroup analysis revealed the strength of association dropped when the hindfoot had a valgus alignment.

SIGNIFICANCE

This study confirmed that the FPI is a valid tool for assessing foot position. However, correlation between the FPI and 3D biometrics fell in the valgus aligned hindfoot so caution must be used when the FPI is used for assessment in this population.

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.

Rasch Analysis of Reliability and Validity of Scores From the Foot and Ankle Ability Measure (FAAM)

BACKGROUND

The purpose of this study was to determine the reliability and validity of scores from the Foot and Ankle Ability Measure (FAAM) Activities of Daily Living (ADL) and Sports scales in patients who have a variety of ankle injuries.

METHODS

All patients who underwent surgical treatment for an ankle injury and completed the FAAM ADL and Sport scales were included in this study (n = 456; 192 females, 264 males). The average age was 47.6 years (range, 18-79 years). The average time to follow-up was 3.8 years (range, 2.0-7.7 years). All data were collected prospectively and reviewed retrospectively. A reliability and validity analysis, utilizing the Rasch measurement model, a special case of item response theory (IRT), was conducted.

RESULTS

Reliability was very good. For FAAM ADL, person reliability was 0.87 and item reliability was 0.99. For FAAM Sport, person reliability was 0.89 and item reliability was 1.0. Infit mean square (MNSQ) values, which assess internal scale validity, were examined. For FAAM ADL, items 11 (coming up on your toes) and 10 (squatting) were high (2.27 and 2.08, respectively). All other infit values were within the acceptable range of 0.5 to 1.7. For FAAM Sport, all infit values were within the acceptable range. Outfit MNSQ values, which assess the FAAM ADL and Sport rating scale function, were examined. Three items from FAAM ADL were beyond the acceptable range. Items 10 and 11 from FAAM ADL had high outfit MNSQ values (2.15 and 1.98, respectively). Item 19 (light to moderate work) item had a marginally low outfit MNSQ of 0.48. For FAAM Sport, all outfit values were within the acceptable range.

CONCLUSION

There was very good evidence of the reliability and validity of FAAM ADL and FAAM Sport scores. Two FAAM ADL items may indicate the need for further scale development for use in a diverse surgical ankle population.

LEVEL OF EVIDENCE

Level III, comparative series.

Is There Any Association Between Foot Posture and Lower Limb-Related Injuries in Professional Male Basketball Players? A Cross-Sectional Study

BACKGROUND

Several studies have shown that foot posture is related to the incidence of ankle sprains in athletes and in nonathletic populations, but this association has not previously been considered in basketball players. This study investigates the relationship between foot posture and lower limb injuries in elite basketball players.

DESIGN AND METHOD

Two hundred twenty participants were recruited as a convenience sample. The players had a mean age of 22.51 ± 3.88 years and a body mass index of 23.98 ± 1.80. The players' medical records were accessed from the preceding 10 years, and injuries were recorded according to their location (knee, foot, and/or ankle). In addition, the Foot Posture Index (FPI) was scored for each player, and their playing positions were noted.

RESULTS

An average FPI score of 2.66 was obtained across all players, with guards presenting a significantly lower average FPI of -0.48 (P < 0.001) compared with the rest of playing positions, indicating a more supinated foot. However, center players presented an average FPI of 5.15 (P < 0.001), indicating a more pronated foot. The most common injuries observed were lateral ankle sprain (n = 214) and patellar tendinopathy (n = 126). Patellar tendinopathy was more common in supinated feet (30.08%) compared with 20.7% and 19.8% in pronated and neutral feet, respectively.

CONCLUSIONS

The most common lower limb injuries observed in basketball players were lateral ankle sprain and patellar tendinopathy. Patellar tendinopathy was more commonly associated with the supinated feet. Guard players tended to have a more supinated foot, whereas centers presented a more pronated foot.

Foot Shape and Asymmetry in the Charcot Foot: Assessment Using the Foot Posture Index

BACKGROUND

Charcot neuroarthropathy (CN), or the Charcot foot, is a complication usually associated with diabetes that frequently results in changes in foot shape and structure that have an effect on function and risk of ulceration. This study aimed to assess foot shape and asymmetry in CN using the Foot Posture Index (FPI-6).

METHODS

Case notes of patients with CN seen in a diabetic orthotic clinic were reviewed, and available FPI-6 data were analyzed. A comparison group of patients with diabetes without CN was also identified. Groups were compared according to published ranges of foot posture and asymmetry using the Fisher exact test.

RESULTS

Twenty-seven patients with CN with 28 affected feet and a comparison group of 27 patients with diabetes only were identified. There was large variation in FPI-6 scores in affected (1 to 12) and unaffected (-1 to 10) feet. Mean scores for affected feet (6.82) and unaffected feet (5.05) differed significantly (P = .005). Considering all FPI-6 scores as positive numbers to indicate mean absolute difference between affected and unaffected feet, CN-affected feet differed by a mean of 3.00 points from unaffected feet. Patients in the CN group were less likely to have asymmetry in the normal range than the comparison group (P = .0146).

CONCLUSIONS

This study provides new data on foot shape after CN. Patients with CN have feet that are significantly asymmetrical, and the affected foot may be more pronated or supinated. Feet affected by CN are characterized by shape, which is more frequently outside the normal range. The FPI-6 may be suitable for more widespread use in assessment and outcome measurement.

Coexistence of plantar calcaneal spurs and plantar fascial thickening in individuals with plantar heel pain

Objectives

To examine associations between plantar calcaneal spurs, plantar fascia thickening and plantar heel pain (PHP), and to determine whether tenderness on palpation of the heel differentiates between these presentations.

Methods

Adults aged ⩾50 years registered with four general practices were mailed a Health Survey. Responders reporting foot pain within the last 12 months underwent a detailed clinical assessment. PHP in the past month was documented using a foot manikin. Plantar calcaneal spurs were identified from weight-bearing lateral radiographs and plantar fascia thickening (defined as >4 mm) from ultrasound. Tenderness on palpation of the plantar fascia insertion was documented. Associations between these factors and PHP were explored using generalized estimating equations.

Results

Clinical and radiographic data were available from 530 participants (296 women, mean [s.d.] age 64.9 [8.4] years), 117 (22.1%) of whom reported PHP. Plantar calcaneal spurs and plantar fascia thickening were identified in 281 (26.5%) and 501 (47.3%) feet, respectively, but frequently coexisted (n = 217, 20.4%). Isolated plantar calcaneal spurs were rare (n = 64, 6.0%). Participants with PHP were more likely to have a combination of these features compared with those without PHP (odds ratio 2.16, 95% CI 1.24, 3.77, P = 0.007). Tenderness on palpation of the heel was not associated with plantar calcaneal spurs or plantar fascia thickening, either in isolation or in combination, in those with PHP.

Conclusion

Plantar calcaneal spurs and plantar fascial thickening are associated with PHP, but frequently coexist. Tenderness on palpation of the heel does not appear to differentiate between clinical presentations of PHP.

The relationship between foot posture index and resting calcaneal stance position in elementary school students

BACKGROUND

Static foot assessment is commonly performed in clinical practice to classify foot type for prescribing therapeutic interventions. Foot posture index is known to be a reliable indicator for foot position. Resting calcaneal stance position angle is used widely to determine foot posture and manufacture orthoses for pediatric flat foot patients. However, the relationship between foot posture index and resting calcaneal stance position angle in elementary school students is currently unclear.

RESEARCH QUESTION

To investigate the relationship between foot posture index and resting calcaneal stance position angle in elementary school students.

METHODS

Between January 2016 and December 2017, 208 elementary school students (average age, 10.3 years; range, 8-13 years) were enrolled for this study. All students were examined physically by one practitioner to measure foot posture index and resting calcaneal stance position angle. Age, gender, and body mass index were analyzed for factors associated with flat foot prevalence. This study was conducted as a retrospective comparative study. Associations between foot posture index and resting calcaneal stance position angle were determined by Pearson's correlation analysis.

RESULTS AND SIGNIFICANCE

When measured by foot posture index and resting calcaneal stance position angle, the overall prevalence of flatfoot was 29% and 24% in the right foot and 26% and 23% in the left foot, respectively. Resting calcaneal stance position angle and foot posture index score showed moderate correlation in Pearson's correlation analysis (left side foot: kappa value = 0.710; right side foot: kappa value = 0.704).

CONCLUSION

There is a moderate correlation between foot posture index and resting calcaneal stance position angle in elementary school students. Thus, both foot posture index with proven validity and reliability and resting calcaneal stance position widely used in the manufacture of insoles can be used as important biomechanical evaluation tools for feet in clinical settings.

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.