Introduction: Persistent heel pain from plantar fasciitis and calcaneal spurs, as well as metatarsalgia, are very common and prevalent complaints in the Brazilian population. One of the recommended treatments for these conditions in the literature is the use of insoles. However, the use of this feature requires the individual to wear closed shoes and this is an obstacle to treatment in cities with hot weather. Thinking about an alternative treatment, the customized slippers with the corrective elements of the insoles can be an alternative to increase the adhesion to this type of treatment. Objective: To evaluate the effectiveness of the insoles adapted in slippers in the improvement of the pain and the function in individuals with persistent pains in the backfoot of the city of Santa Cruz, RN. Methodology: This is a double-blind, randomized, controlled clinical study in which 66 patients diagnosed with persistent back pain and metatarsalgias will be divided into two groups. The intervention group will receive a customized slipper with foot pieces and synthetic leather cover, and the control group will receive a slipper without customization, only with a synthetic leather cover as used by the intervention group. The evaluator and the patient will be considered blind. Evaluations will be performed at baseline (T0), after 12 weeks of wearing the slippers (T12) and a reassessment at week 16 (T16) for pain monitoring. The evaluation instruments used will be the EVA (visual pain scale) and the algometer in the painful region of the foot; FFI - Foot Function Index questionnaire and FAAM questionnaire - Foot and Ankle Ability Measure for functional evaluation, and finally the 6 - minute walking test for walking performance. Statistical analysis: Data will be analyzed by t-test, Mann-Whitney test, repeated-measures ANOVA and intention-to-treat analysis.

The evaluations for the prescription of the insoles will be made at the Physiotherapy School Clinic of FACISA / UFRN and a podoscope will be used to evaluate the foot typology and other morphological aspects, a pen to print the feet and make a mold for making the insoles. insoles, and different prosthetic parts molded previously.

The volunteers will be invited to participate in the research and, upon accepting, will be informed of the research procedures, sign the informed consent form and only then will be evaluated by the blind evaluator of the study. It will also be informed that it can be drawn for any of the two groups (intervention group or control group). Allocation in groups will be done randomly, by lot.

All volunteers, regardless of groups, will be evaluated individually, in a comfortable room, barefoot and wearing shorts or shorts.

Evaluations will occur at the baseline (T0), after 12 weeks of use of the slippers (T12) and at the follow up 4 weeks after the end of the intervention (T16).

The following evaluation tools will be used:

• Pain by Visual Analog Scale and algometer;
• The function of the foot by the FFI (Foot Function Index) questionnaire;
• Foot and ankle functionality by FAAM (Foot and Ankle Ability Measure);
• Functional ability by the 6-minute walk test;
• After this step, the volunteers will be evaluated on the podoscope using the foot pieces for the postural evaluation (fig 3). In the protocol, the volunteer's posture will be evaluated using the foot pieces to verify their influence on static balance and postural asymmetries. The volunteers will be evaluated in the frontal and sagittal planes.
• Finally, the volunteers will carry out the plantations (fig 4) that will be sent to make the slippers.

6.2 Calculation of the sample The investigators will select 66 patients from the list of patients at the Physiotherapy School Clinic of the FACISA / UFRN, with diagnosis of calcaneal spurs, fasciitis and / or metatarsalgia, according to clinical evaluation criteria. The project will also be broadcast by local radio and media.

The sample size was calculated based on the EVA variable, considering a power of 90%, a significance of 5% and a loss rate of 10%. Based on the study by Chuter, Searle and Spink (2016), where with similar methods they found a difference of 1.3 points, considering the standard deviation of this variable being equal to 1.8. Based on these data, a sample of 66 subjects with 33 in each group was necessary to detect a clinically important difference. The calculation was based on comparisons of two samples by Gpower 3.1 software. The randomization will be through a computer program, and from this result, the chips will be placed in opaque and sealed envelopes to maintain allocation secrecy.

6.3 Inclusion criteria Patients of both sexes with a diagnosis of persistent back pain and / or pain in the head region of the metatarsals for more than 3 months, aged 18-60 years, accustomed to wearing slippers that are not performing other types of physical therapy and sign the ICF.

6.4 Exclusion Criteria Patients with foot wounds, previous foot and ankle surgeries, rheumatic diseases and / or skin diseases and those reporting that they can not wear slippers.

6.5 Interventions Intervention Group (GI) - the intervention group volunteers will receive a pair of custom slippers with perforated synthetic leather cover. They will be advised to wear the slipper for 4 hours in the first week and up to 8 hours after that period. Should any part disturb you, the participant should return immediately to the appropriate adjustments to be made in the slipper.

Control group (CG) - control group volunteers will receive custom slippers with the same coverage as those used by GI. The difference will be that these slippers will not have the elements podais, will be a slipper with smooth surface.

Inclusion Criteria:

• Patients of both sexes with a diagnosis of persistent back pain and / or pain in the head region of the metatarsals for more than 3 months, aged 18-60 years, accustomed to wearing slippers that are not performing other types of physical therapy and sign the ICF.

Exclusion Criteria:

• Patients with foot wounds, previous foot and ankle surgeries, rheumatic diseases and / or skin diseases and those reporting that they can not wear slippers.

there is not a plan to make individual participant data (IPD) available to other researchers.

Participants will be informed that they will be drawn to participate in one of the two groups (intervention group or control group). Allocation in the groups will be done randomly, by lot, following the order of randomization, keeping the confidentiality, ie, one should not know to which group the participant will be sent before he / she agrees to be evaluated and sign the TCLE.