Cross-Cultural Adaptation and Validation of the Pain Scale for Plantar Fasciitis to Spanish.

The aim of this study was the validation and transcultural adaptation of the Pain Scale for Plantar Fasciitis to Spanish, following the steps defined by "Guidelines for the process of cross-cultural adaptation of self-report measures." A cross-sectional study was driven in 153 patients with unilateral plantar fasciitis diagnosis. Statistical analysis measured the internal consistency, the test-retest reliability, the construct validity with the Spanish version of Foot and Function Index, and a factorial analysis. The questionnaire Pain Scale for Plantar Fasciitis was also given to a group of 10 people who received a physiotherapy treatment based on manual therapy, therapeutic exercise, and health education, which aim was to determine the questionnaire's sensitivity to changes. The questionnaire showed high internal consistency and test-retest reliability (Cronbach's α = 0.99, intraclass correlation coefficient = 0.98 [0.97-0.98]), good convergent validity with a moderate correlation with the Foot and Function Index (rho = 0.677, p < .0001) and no floor or ceiling effects were detected. The factorial analysis revealed that the first 3 factors showed 42.47% of variance, finding only 1 latent feature. Statistically significant differences were found in those patients who received physiotherapy treatment after 1 month, revealing that the questionnaire was sensitive to changes in the symptoms of subjects with plantar fasciitis. The Spanish version of Pain Scale for Plantar Fasciitis has proved to be a valid, reliable, and change-sensitive tool for patients with plantar fasciitis.