Arch-supports and plantar fasciitis: A prospective study incorporating patient-reported outcomes and finite element analysis.

Abstract

Arch-support insoles are used to reduce symptoms in patients with plantar fasciitis. However, the evidence supporting their clinical effectiveness is mixed. This study evaluated the clinical effects of arch-support insoles by assessing changes in symptom relief (primary outcome), radiographic foot alignment and plantar pressure distribution. A single-arm, prospective study was conducted, and patients aged 18-65 years with a diagnosis of plantar fasciitis were included. Participants received arch-support insoles at baseline and were evaluated for changes in pain, foot alignment, and plantar pressure distribution. Pain outcomes were measured using Patient-Reported Outcome Measurement Information System scores for pain intensity and interference at baseline, 4, 8 and 12 weeks. Weight-bearing computed tomography and x-rays were obtained at baseline to assess foot alignment with and without insoles. Finite Element analysis was performed using baseline scans to evaluate heel plantar pressure. Statistical tests, Wilcoxon signed-rank, with statistical significance set at <i>p</i> = 0.05. Results are reported as medians with interquartile ranges. Twenty-nine patients (median age = 36 years, body mass index = 26 kg/m²) were enroled, with a female-to-male ratio of 18:11. Pain scores showed improvement from 4 weeks onward (<i>p</i> < 0.001). Radiologic assessment revealed increased navicular height on computed tomography (<i>p</i> = 0.003) and heightened medial longitudinal arch on radiographs. Finite element analysis (<i>n</i> = 12) showed reduced heel stress by 34.7% (peak) and 14.6% (average) (<i>p</i> = 0.002). Follow-up response rates were 87% at Weeks 4 and 12 and 63% at the eighth week. Our findings underscore the short-term effect of arch-support insoles in the treatment of plantar fasciitis. The therapeutic benefit might be correlated with anatomical foot realignment and pressure redistribution, as supported by radiological and biomechanical data. Studies with longer follow-up and controlled designs are needed to determine the durability and causal nature of these effects beyond 3 months. Level IV.