Custom foot orthoses improve first-step pain in individuals with unilateral plantar fasciopathy: a pragmatic randomised controlled trial

BACKGROUND: Foot orthoses are routinely used to treat plantar fasciopathy in clinical practice. However, minimal evidence exists as to the effect of both truly custom designed foot orthoses, as well as that of the shoe the foot orthoses are placed into. This study investigated the effect of wearing custom foot orthoses and new athletic footwear on first-step pain, average 24-h pain and plantar fascia thickness in people with unilateral plantar fasciopathy over 12 weeks. METHODS: A parallel, three-arm randomised controlled trial with blinding of participants and assessors. 60 participants diagnosed with unilateral plantar fasciopathy were randomised to either custom foot orthoses and new shoes (orthoses group), a sham insole with a new shoes (shoe group) or a sham insole placed in the participant’s regular shoes (control group). Primary outcome was first-step pain. Secondary outcomes were average 24-h pain and plantar fascia thickness measured on ultrasound. Outcomes were assessed at baseline, 4 week and 12 week trial time-points. RESULTS: At 4 weeks, the orthoses group reported less first-step pain (p = 0.002) compared to the control group. At 12 weeks, the orthoses group reported less first-step pain compared to both the shoe (p = < 0.001) and sham (p = 0.01) groups. Both the orthoses (p = < 0.001) and shoe (p = 0.006) groups reported less average 24-h pain compared to the control group at 4 and 12 weeks. The orthoses group demonstrated reduced plantar fascia thickness on ultrasound compared to both the shoe (p = 0.032) and control groups (p = 0.011). CONCLUSIONS: Custom foot orthoses in new shoes improve first-step pain and reduce plantar fascia thickness over a period of 12 weeks compared to new shoes alone or a sham intervention. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (ACTRN 12613000446763). Submitted on the 10th of April 2013 and registered on the 18th of April 2013. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12891-018-2131-6) contains supplementary material, which is available to authorized users.