Physical therapy combined with flip-flops versus physical therapy alone in plantar fasciitis: analysis of clinically meaningful improvements

Abstract

Objective: To compare the effectiveness of physical therapy (PT) combined with flip-flops versus PT alone in plantar fasciitis, focusing on the number of participants achieving clinically significant improvements according to minimum clinically important difference (MCID) criteria.

Materials and Methods: Sixty-six participants (aged 20–60 years) were randomly assigned to either the intervention group (PT with flip-flops, n=33) or the comparative group (PT alone, n=33) for 8 weeks. Both groups received PT (plantar fascia stretching, calf stretching, subtalar mobilization) and performed the same exercises at home as administered by therapists. The intervention group additionally wore Vari-Ving flip-flops, designed with arch support and cushioning features, for ≥4 hours daily. Outcome measures included first-step morning pain, first step post-inactivity pain, average pain, pressure pain threshold, Foot Function Index, Lower Extremity Functional Scale (LEFS), and Global Rating of Change (GRC).

Results: All participants completed the study with 100% adherence. Both groups showed significant improvements across all measures (p<0.01). For first-step morning pain, 54 participants (27 per group) achieved MCID, while for post-inactivity pain, 53 participants (intervention: 27, control: 26) reached MCID, with the intervention group showing marginally greater improvement (p=0.05 with medium effect). Functionally, 34 participants (17 per group) met MCID on LEFS, and 40 participants (20 per group) showed meaningful recovery on GRC, with 11 intervention participants achieving substantial improvements (+5 GRC).

Conclusion: Both interventions demonstrated clinically significant improvements. Home exercises, replicating therapist-administered techniques, effectively reduced pain and improved function, while supportive flip-flops showed potential as a valuable adjunct therapy enhancing overall effectiveness.