Relationships between static foot alignment and dynamic plantar loads in runners with acute and chronic stages of plantar fasciitis: a cross-sectional study

BACKGROUND: The risk factors for the development of plantar fasciitis (PF) have been associated with the medial longitudinal arch (MLA), rearfoot alignment and calcaneal overload. However, the relationships between the biomechanical variables have yet to be determined. OBJECTIVE: The goal of this study was to investigate the relationships between the MLA, rearfoot alignment, and dynamic plantar loads in runners with unilateral PF in acute and chronic phases. METHOD: Cross-sectional study which thirty-five runners with unilateral PF were evaluated: 20 in the acute phase (with pain) and 15 with previous chronic PF (without pain). The MLA index and rearfoot alignment were calculated using digital images. The contact area, maximum force, peak pressure, and force-time integral over three plantar areas were acquired with Pedar X insoles while running at 12 km/h, and the loading rates were calculated from the vertical forces. RESULTS: The multiple regression analyses indicated that both the force-time integral (R2=0.15 for acute phase PF; R2=0.17 for chronic PF) and maximum force (R2=0.35 for chronic PF) over the forefoot were predicted by an elevated MLA index. The rearfoot valgus alignment predicted the maximum force over the rearfoot in both PF groups: acute (R2=0.18) and chronic (R2=0.45). The rearfoot valgus alignment also predicted higher loading rates in the PF groups: acute (R2=0.19) and chronic (R2=0.40). CONCLUSION: The MLA index and the rearfoot alignment were good predictors of plantar loads over the forefoot and rearfoot areas in runners with PF. However, rearfoot valgus was demonstrated to be an important clinical measure, since it was able to predict the maximum force and both loading rates over the rearfoot.

Tradução e adaptação cultural do Foot Function Index para a língua portuguesa: FFI - Brasil / Translation and cross-cultural adaptation of FFI to Brazilian Portuguese version: FFI - Brazil

RESUMOObjetivo:Realizar a tradução e a adaptação cultural do questionário Foot Functional Index (FFI), que avalia a funcionalidade do pé, para a versão em língua portuguesa do Brasil.Métodos:A versão brasileira do FFI foi baseada no protocolo proposto por Guillemin. O processo aplicado consistiu em: (1) tradução; (2) retrotradução; (3) análise do comitê de especialistas; (4) pré-teste. A versão brasileira foi aplicada em 40 pessoas, homens e mulheres com idade superior a 18 anos, com fasciíte plantar e metatarsalgia, para verificar o nível de compreensão do instrumento. A versão final foi definida após se obter menos de 15% de “não compreensão” em cada item.Resultados:Foram alterados termos e expressões para obter equivalência cultural do FFI. As alterações feitas foram baseadas nas sugestões dos pacientes.Conclusão:Após a tradução e adaptação cultural do questionário, foi concluída a versão da língua portuguesa do Brasil do FFI.

ABSTRACTObjective:Perform the translation and cultural adaptation of the questionnaire Foot Functional Index (FFI), which assesses the functionality of the foot, to the Brazilian Portuguese version.Method:The Brazilian version development of FFI questionnaire was based on the guideline proposed by Guillemin. The applied process consisted of: (1) translation; (2) back-translation; (3) committee review; (4) pretesting. The Portuguese version was applied to 40 patients, both genders, aged over 18 years old, with plantar fasciitis and metatarsalgia to verify the level of the instrument comprehension. The final Brazilian version of the FFI was set after getting less than 15% of “not understanding” on each item.Results:Some terms and expressions were changed to obtain cultural equivalence for FFI. The terms that were incomprehensible were changed in accordance of patient suggestions.Conclusion:After the translation and cultural adaptation of the questionnaire, the final Portuguese version of FFI was concluded.

Rearfoot alignment and medial longitudinal arch configurations of runners with symptoms and histories of plantar fasciitis

OBJECTIVE: To evaluate and compare rearfoot alignment and medial longitudinal arch index during static postures in runners, with and without symptoms and histories of plantar fasciitis (PF). INTRODUCTION: PF is the third most common injury in runners but, so far, its etiology remains unclear. In the literature, rearfoot misalignment and conformations of the longitudinal plantar arch have been described as risk factors for the development of PF. However, in most of the investigated literature, the results are still controversial, mainly regarding athletic individuals and the effects of pain associated with these injuries. METHODS: Forty-five runners with plantar fasciitis (30 symptomatic and 15 with previous histories of injuries) and 60 controls were evaluated. Pain was assessed by a visual analogue scale. The assessment of rearfoot alignment and the calculations of the arch index were performed by digital photographic images. RESULTS: There were observed similarities between the three groups regarding the misalignments of the rearfoot valgus. The medial longitudinal arches were more elevated in the group with symptoms and histories of PF, compared to the control runners. CONCLUSIONS: Runners with symptoms or histories of PF did not differ in rearfoot valgus misalignments, but showed increases in the longitudinal plantar arch during bipedal static stance, regardless of the presence of pain symptoms.