Effects of insoles adapted in flip-flop sandals in people with plantar fasciopathy: a randomized, double-blind clinical, controlled study

Abstract

Objective: To evaluate the effects of insoles adapted into flip-flop sandals on pain and function in individuals with plantar fasciopathy (PF). Design: Randomized, double-blind controlled study. Setting: Physiotherapy clinic of the Faculty of Health Sciences of Trairi, Federal University of Rio Grande do Norte, Santa Cruz, Brazil. Subjects: Sixty-six patients of both genders with PF were randomized into two groups: sandal insole group (SI; n = 34), which received a pair of custom flip-flop sandals with insoles covered with smooth synthetic leather; and plain sandal group (PS; n = 32), which received an identical pair of flip-flop sandals, but without the insoles. Interventions: Patients were instructed to wear the flip-flops for 12 weeks for at least 4 hours/day. Main measures: Pain (visual analogue scale—VAS) in the morning and at the end of the day were considered primary outcomes. Function (Foot Function Index—FFI and Foot and Ankle Ability Measure—FAAM) and functional capacity (6-minute walk test—6MWT) were considered secondary outcomes. The outcomes were evaluated at baseline and immediately after the intervention by a blind assessor. Results: Between-group differences were observed in terms of morning pain (mean difference (MD) = –1.82 cm; 95% confidence interval (CI) = –3.3 to −0.3; P = 0.016) and function (MD = –0.10; 95% CI = –0.19 to −0.01; P = 0.023) after the interventions with the SI group showing superior improvements in comparison to the PS group. Conclusion: The use of insoles adapted in flip-flop sandals for 12 weeks was effective at improving pain and function in individuals with PF. Level of evidence: 1b.

Effects of insoles adapted in flip-flop sandals for persistent heel pain: a protocol for a sham-controlled randomised trial

“…A previous study observed that insoles adapted in flip-flop sandals were superior to flat flip-flop sandals after a 12-week use in individuals with heel pain caused by plantar fasciitis. 15 Another study observed that flip-flop sandals with moulded foot-bed improved foot pain and function of individuals with foot pain in the short term (12 weeks) compared with normal sandals. 17 Vicenzino et al 16 compared the effects of a contoured sandal for plantar heel pain with flat flip-flops and contoured in-shoes insole orthosis.…”

“…14 Insole-type orthoses are generally restricted to closed footwear (eg, shoes and sneakers), which may be an obstacle in hot climates. [15][16][17] Thus, adapting insoles into flip-flop sandals may be a practical and comfortable alternative for individuals with persistent heel pain living in tropical regions. A recent clinical trial 15 demonstrated that insoles adapted in flip-flop sandals (support or filling for plantar arches according to foot type) improved morning pain intensity of individuals with persistent heel pain after 12 weeks of intervention compared with flipflop sandals with sham insoles (flat insole).…”

“…18 19 Intervention time is another relevant aspect, and the effects of a 12-week treatment using insoles adapted to flip-flop sandals are still unknown. [15][16][17] Therefore, we present a protocol for a pragmatic study to investigate the short-term and medium-term effects of insoles adapted in flip-flop sandals on pain intensity, foot function, functional walking capacity and pain catastrophising of individuals with persistent heel pain. We hypothesise that insoles adapted in flip-flop sandals will reduce pain intensity and improve foot function, functional walking capacity and pain catastrophising in individuals with compared with sham insoles in individuals with persistent heel pain.…”

“…This strategy ensures that individuals will not wear the sandals for less than 4 hours. 15 Use of other analgesic modality Register of usage of other analgesic modalities: before each assessment, individuals will be asked about the use of therapeutic resources for heel pain control (eg, ice or heat packs, massage) or any analgesic medication they might have used the day before the assessment, either for heel pain or general pain. Figure 5 presents primary and secondary outcomes and instruments used at each assessment (T0 -baseline, T6, T12 and T16).…”

“…The sample size was calculated based on the NRPS from a previous study. 15 The statistical power of 80% was used to detect a mean difference of 1.8 points in pain, based on a difference found between groups in a study by Costa et al 15 Each group will need 36 individuals considering an estimated SD of 3.2 points and a 5% significance level. However, a sample loss of 10% was added, leading to a sample of 40 individuals per group.…”