Ultrasonographic examination of plantar fasciitis: a comparison of patient positions during examination

BACKGROUND Musculoskeletal ultrasound is a non-invasive and low-cost modality for real-time visualisation of the plantar fascia. Ultrasound examination for plantar fasciitis is generally performed with the patient in a prone position, although the rational for using a prone position has not been validated. The aim of the study was to investigate if ultrasound examination in a supine position, which is more comfortable than the prone position, is valid. METHODS We conducted a prospective study of 30 participants with plantar fasciitis, 8 men (27 %) and 22 women (73 %), with a mean age of 53.9 ± 12.6 (range, 32 to 77) years, and an equal distribution of left and right feet. The plantar heel was divided into three portions for ultrasound examination: medial, central and lateral. Two measurements of plantar fascia thickness were obtained for each portion, with participants in 2 positions (supine and prone) and for 2 ankle postures (neutral and 15° of plantarflexion). Mean measurements of plantar fascia thickness were compared between the two positions (Wilcoxon signed rank tests for non-normally distributed data and paired t-tests for normally distributed data). Participants were asked to report their preferred position for examination, supine or prone. RESULTS The measured thickness was comparable for both supine and prone positions, for both ankle postures, neutral and 15° of plantarflexion (p > 0.05). A specific self-reported preferred position was not identified. CONCLUSIONS Ultrasound examination of plantar fasciitis can be performed in the supine position without any significant difference in measurement compared to examination in the conventional prone position. TRIAL REGISTRATION The Catholic Medical Center Office of Human Research Protection Program (CMC-OHRP)/Institutional Review Board approved the current study (Approval No. KC12DISI0338), and all participants provided their written informed consent for participation and publication.