Effects of insoles adapted in flip-flop sandals in patients with persistent plantar heel pain: A sham-controlled randomised trial

Abstract

Objective To evaluate the use of custom-made insoles adapted to flip-flops on pain intensity, foot function, and functional walking ability in individuals with persistent plantar heel pain in the short and medium term. Design Randomised controlled trial. Setting Flip-flop sandals in patients with persistent plantar heel pain. Main measures Participants (n = 80) were assessed at baseline, six and 12 weeks after the intervention, and 4 weeks post-intervention. Results For the primary outcomes, after 6 weeks of intervention, no between-group difference was observed in the intensity of morning pain or pain with walking, mean difference = −0.4 (95% confidence intervals = −1.5 to 0.8). Similarly, after 12 weeks of intervention, no between-group difference was observed in the intensity of morning pain or pain with walking, mean difference = −0.7 (95% confidence intervals = −1.9 to 0.6). Finally, at 4 weeks after the end of the intervention, there was no between-group difference in morning pain or pain on walking, mean difference = 0.01 (95% confidence intervals = −1.4 to 1.4). All differences and confidence intervals were smaller than the minimum clinically important difference for pain (2 points). There were no differences between the groups for the secondary outcomes. In addition, the mean differences were smaller than the minimum clinically important differences for pain intensity, foot function and functional walking ability. Conclusion Custom-made insoles fitted to flip-flops did not differ from flip-flops with sham insoles in improving pain intensity, foot function and functional walking ability in people with persistent heel pain. Trial registration: ClinicalTrials.gov (Identifier: NCT04784598). Data of registration: 2023-01-20