The authors have declared that no competing interests exist.
Plantar fasciitis is one of the common foot complaints that is chronic and can induce dysfunction. Total contact insole (TCI) is simple but effective in treating plantar fasciitis. Despite its effect, the cost and long duration for production have been the major flaws. Therefore, we developed a newly designed three-spike insole (TSI) that can be commercially productive and compared its clinical outcomes to TCI.
Patients with plantar fasciitis refractory to conservative treatment for more than 6 weeks were candidates. We produced insoles with hardness of 58 ± 5 Shore-A. Twenty-eight patients were randomized with equal allocation to either TSI or TCI. The following assessment tools were used: visual analog scale (VAS), American Orthopaedic Foot and Ankle score, Foot and Ankle Outcome Score, Karlsson-Peterson (KP) score, Short Form-36 for quality of life, and Foot Function Index. Non-inferiority was declared if VAS was within the statistical variability of minimal important difference. A blinded assessor evaluated the groups at baseline and after 6, 12, and 24 weeks.
The groups were homogenous for majority of variables at baseline. Overall patient-reported satisfaction showed improvement from mean 5.2 (range, 1–12) weeks of wearing and all clinical outcome scores showed significant improvements in both groups over time on Friedman test (p ≤.032). TSI showed non-inferiority to TCI at each time point. Post hoc analysis revealed that many scales showed significant superiority of TSI at 3 month (p ≤.008) and KP score at 6 month (p < .001).
We reaffirmed that semi-rigid insole is effective in refractory plantar fasciitis and showed TSI restores pedal function more rapidly than TCI. TSI can be not only effective in deriving better clinical outcomes but also be manufactured for popularization to lower the price and producing time of orthosis.
Plantar fasciitis is one of the common foot complaints that is chronic and can induce dysfunction. Approximately 10% of population develops heel pain during lifetime [
Foot orthosis is simple but effective in treating plantar fasciitis. It can be beneficial to patients in that population vulnerable to plantar fasciitis who tend to have a job with a long time walking or standing and not have enough time spent on treatment including stretching exercise or visiting a clinician [
Previous biomechanical studies have proposed that the medial surface of orthosis should stabilize the apical bony structure to effectively support the medial longitudinal arch. The studies have also proposed that the optimal insole contact surface should be over 54% of the plantar fascia to lessen the fascial stress and peak pressure [
A parallel double-blinded randomized controlled study with a 6-month follow-up duration was carried out from February 2019 to April 2020. This study was approved by our institution. Prior to inclusion, all participants voluntarily participated in this study and gave written informed consent; and rights of participants were protected. Patients over 19-year-old with plantar fasciitis refractory to conservative treatment including stretching, resting, ice bag, and extracorporeal shock wave treatment (ESWT) etc. other than orthotics for more than 6 weeks were candidates for this study. Furthermore, patients with visual analog scale (VAS) of 5 or higher pain when taking the first step were included. Exclusion criteria were previous insole use, injection around the foot and ankle within 3 months, pulselessness of dorsalis pedis and posterior tibial artery, other systemic inflammatory diseases, comorbidities that can mimic symptom such as Achilles tendinitis and subtalar arthritis, history of foot and ankle fracture, and hindfoot deformity. This study was registered on the clinical trials registry system and the manuscript was prepared according to the CONSORT statement. This study was approved by the Catholic Kwandong University International St. Mary’s Institutional Review Board (IS18OISI0072) and registered in Clinical Research Information Service (KCT0004737, first registration (14/02/2020)). We retrospectively registered this study because we did not know the existence and necessity of the public registration. However, the authors confirm that all ongoing and related trials for this intervention are registered. All methods were carried out in accordance with relevant guidelines and regulations.
Twenty-eight patients were enrolled from the outpatient clinic and informed consents were obtained. An excel-generated four block randomization list, which was created by a clinician not involved in this trial for concealment, was used to randomly allocate patients to the newly designed three-spike insole (TSI) group or total contact insole (TCI) group. A blinded physician assessed the outcome data.
The sample size was calculated for a non-inferiority trial of 2 independent means between the groups using VAS as the main variable. For determination of the minimal important difference (MID) of 2-cm on a 10-cm pain VAS, a 5% alpha set, 20% beta error, and standard deviation of 1.9 cm were established [
We used a 3-dimensional (3D) printer (Mandme, ®PLABS) to produce an insole. Both feet of all patients were copied with Copyfoam and the copies were sent to a manufacturer. All insoles were manufactured from thermoplastic polyurethane (TPU, density 12 g/cm3) and had a 58 ± 5 Shore-A hardness filling up to 30% of the insole with TPU. Newly designed insole had three hemispheric spikes along the longitudinal medial arch starting from the center of plantar fascia. If a person’s foot was 28.5 cm long, the measured length of plantar fascia in Copyfoam was about 12 cm. Therefore, each spike was designed to have a 2 cm diameter to support approximately 50% of the medial longitudinal arch; height of the first and third spike was 0.8 cm and that of the middle one was 1.2 cm. The first and the third spikes were placed at the most distal and proximal points of the medial longitudinal arch that were thought to be appropriate for stimulating the fascia based on foot posture on Copyfoam. The distance between the spikes differed among the patients depending on the length of the patient’s arch. Based on the initial copied foam, the total contact insole was manufactured to have structures supporting the arch on its medial border like the general customized total contact orthosis (
At baseline, all participants were given either of the above-mentioned insoles according to the randomization for daily use for 6 months. They were instructed to wear it on shoes or slippers as much as they could in a day and were not allowed to have more intervention including stretching exercise during the research. All participants were assessed by a blinded physician at baseline, 6 weeks, 3 months, and 6 months after wearing the insole.
Symptoms, pedal function, and foot and ankle related quality of life were the target evaluation. Clinical outcomes were assessed using maximal pain VAS in a day, American Orthopaedic Foot and Ankle Society (AOFAS) score, Foot and Ankle Outcome Score (FAOS), Karlsson-Peterson (KP) score, Medical Outcomes Study Short Form-36 (SF-36) for quality of life, and Foot Function Index (FFI).
An intention to treat analysis was used—for the patients who were dropped out from further evaluations, the last data collected were used in the subsequent evaluations. Patient demographics and clinical outcomes are presented as mean ± SD or count (percentage). We used Mann-Whitney test for quantitative variables and Fisher’s exact test for categorical variables for comparison between the groups. Non-inferiority test was used to assess the VAS between 2 groups. Friedman test was used for comparison between two groups over time. Post hoc analysis with Mann-Whitney test was conducted with a Bonferroni’s correction, resulting in a significance level set at p < .0125. The level of statistical significance was set at p < .05. The Statistical Package for the Social Sciences (SPSS, version 21.0, IBM Corp., Armonk, NY, USA) was used for all statistical analyses. Non-inferiority test was used to investigate if the newly designed insole would not be inferior to the existing total contact insole.
Twenty-eight patients were randomized to two groups with equal probability; a CONSORT flowchart is shown in
Twenty-eight participants were distributed to 2 groups and 4 participants were lost to follow-up thoroughly. Finally, twelve participants were evaluated in each group.
TSI (N = 14) | TCI (N = 14) | P value | |
---|---|---|---|
Age (years) | 48.2 ± 9.9 | 48.2 ± 8.8 | .999 |
Male gender | 4 (28.6%) | 4 (28.6%) | .999 |
Side (right: left: both) | 5: 2: 7 | 6: 3: 5 | .663 |
Height (cm) | 162.9 ± 6.9 | 162.5 ± 8.2 | .787 |
BMI (kg/m2) | 25.2 ± 2.6 | 25.1 ± 2.7 | .965 |
Symptom duration (months) | 25.3 ± 18.7 | 16.3 ± 11.5 | .173 |
Previous treatment duration (months) | 20.1 ± 19.9 | 8.4 ± 2.9 | .068 |
Insole usage time (hour/day) | 4.8 ± 2.6 | 3.4 ± 3.0 | .875 |
Time to feel improvement with insole (weeks) | 5.6 ± 2.2 | 4.8 ± 2.8 | .630 |
TSI, three spike insole; TCI, total contact insole; BMI, body mass index.
The bending moments of two insoles are drawn in
A) When we assume that the plantar fascia is simply attached at the ends and the load (W, person’s weight) is uniformly distributed, the bending moment at some point (s) can be calculated as formula M(s). Bending moments at each point of B-D would be 0.8dW, 1.25dW, and 0.8dW if we assume that the point B and D are 2d away from each end. B) If multiple three concentrated loads are weighed on, the bending moments at each point of B-D would be 1.0dW, 1.45W, and 1.0dW, respectively. RA, reaction force at point A; RE, reaction force at point E (each RA and RE can be calculated as ‘0.5W’ here).
Mean differences of VAS with 95% confidential interval (CI) at each time point of 6 weeks, 3 months, and 6 months were 0.6 (95% CI 0.6–2.6), 0.8 (95% CI -1.7–0.9), and 0.4 (95% CI -1.6–0.6), respectively. All value differences except for that of 6 weeks were within MID. The scale at 6 weeks showed superiority of TSI. These indicate that the TSI shows non-inferiority to TCI according to VAS.
Almost all parameters except for KP score, Sport/Rec subscale in FAOS, and PCS in SF-36 showed significant improvement at 6 weeks in all participants (p ≤.027). Comparison between the groups are shown in
TSI, three spike insole; TCI, total contact insole. * Significant p value < .05 between the groups. Horizontal brackets indicate overall significant improvement of the whole participants from the baseline.
Baseline | 6 weeks | 3 months | 6 months | Friedman test | ||||||
---|---|---|---|---|---|---|---|---|---|---|
TSI | TCI | TSI | TCI | TSI | TCI | TSI | TCI | Chi square | P value | |
VAS | 6.2(1.5) | 6.3(1.5) | 3.4(2.1) | 4.8(2.3) | 3.4(1.7) | 3.1(1.5) | 2.4(1.3) | 1.9(1.5) | 61.1 | |
AOFAS score | 59.2(13.0) | 56.6(19.3) | 77.5(10.1) | 77.5(6.8) | 77.0(11.2) | 63.5(11.1) | 75.4(11.6) | 77.3(8.4) | 23.7 | |
KP score | 47.1(22.3) | 57.1(25.9) | 69.0(22.7) | 66.1(17.4) | 25.0 | |||||
FFI | 85.3(30.3) | 89.4(35.6) | 70.6(39.9) | 64.0(21.8) | 44.0(37.7) | 54.5(31.2) | 33.6 | |||
FAOS subscales | ||||||||||
Pain | 38.7(18.3) | 51.5(25.1) | 63.5(21.6) | 72.1(11.6) | 74.0(5.8) | 83.7(4.1) | 25.7 | |||
Symptoms | 78.2(8.4) | 76.6(7.3) | 86.1(9.0) | 85.0(5.9) | 89.3(4.6) | 86.5(4.3) | 20.6 | |||
ADL | 74.8(14.4) | 83.0(14.7) | 87.0(10.5) | 86.7(8.2) | 88.7(7.9) | 87.7(4.5) | 85.5(4.5) | 87.0(3.9) | 10.6 | |
Sport/Rec | 57.9(13.2) | 69.6(28.5) | 68.3(16.9) | 78.0(8.8) | 69.3(14.1) | 73.4(5.2) | 65.2(7.7) | 67.7(11.6) | 8.8 | |
QOL | 24.0(18.4) | 28.6(16.5) | 41.7(24.5) | 53.6(14.9) | 43.8(31.9) | 19.9(10.0) | 57.8(21.1) | 59.4(18.6) | 32.7 | |
SF-36 subscales | ||||||||||
PCS | 54.1(18.1) | 56.8(15.8) | 60.9(18.7) | 63.3(12.9) | 64.5(8.8) | 71.8(8.1) | 17.0 | |||
MCS | 64.3(18.0) | 61.5(9.2) | 78.0(12.7) | 68.6(12.8) | 79.6(4.2) | 75.6(3.5) | 20.5 |
Boldface indicates statistical significance between the groups by post hoc analysis using Mann-Whitney test conducted with a Bonferroni correction (p < .0125). TSI, three spike insole; TCI, total contact insole; VAS, visual analog scale; AOFAS, American Orthopaedic Foot and Ankle Society; KP, Karlsson-Peterson; FFI, foot function index; FAOS, foot and ankle outcome score; ADL, activities of daily living; Sport/Rec, sport and recreational function; QOL, quality of life; SF-36, medical outcomes study short form-36; PCS, physical component summary; MCS, mental component summary.
This study showed that a newly designed TSI showed non-inferiority to conventional TCI according to VAS and a relatively rapid functional improvement during the 6-month follow up. Both types of insoles were effective enough to reduce pain and increase pedal function and foot-related quality of life at mean 5.2 weeks of put on. Pain scale did not show significant differences at every time point between the groups and value differences of VAS were within MID. Moreover, KP score, FFI, pain and symptom subscales in FAOS, and SF-36 scores at 3 months were significantly superior in TSI group compared to TCI group. The KP score at 6 months in TSI group was significantly higher as well. These results imply that total contact support of medial longitudinal arch is not essential for symptom relief in plantar fasciitis. Previous biomechanical studies mentioned the requisitions of a proper insole for plantar fasciitis. Kogler et al. suggested that orthosis must lower the strain of the foot and the medial surface of the orthosis must stabilize the apical bony structure of the medial longitudinal arch to support it effectively [
We can explain why sham orthoses have shown inferior results to custom or prefabricated orthoses with the above-mentioned reasons. Sham orthoses lack sufficient supportive structure for medial longitudinal arch. Landorf et al. compared sham orthosis, prefabricated orthosis, and customized orthosis in their randomized trial [
On the other hand, there have been many debates whether prefabricated orthosis is comparable to custom orthosis. Wrobel et al. compared custom foot orthoses, prefabricated foot orthoses, and sham insole on 77 patients in their randomized control study [
Therefore, the clinical results of this study are quite interesting. Newly designed TSI showed not only a non-inferiority but also a significantly exceptional functional improvement and foot-related quality of life during a 6-month follow up. We postulate that these results came from the differences of bending moments in each model. Bigger bending moments in TSI would have added more pressure on plantar fascia and would have led to consequent functional improvements. This multiple concentrated load distribution is easy to position according to the length of the patient’s plantar fascia. Therefore, mass production of therapeutic insoles would be possible if three spikes are placed along the medial plantar arch of the insole for each size of readymade shoes.
Our study has some limitations. First, the sample size is quite small to draw further differences or identities between the groups in this non-inferiority study model. However, similar demographic distribution to both groups and blinded physician who interpreted the patient outcomes could have offset the possible bias. Although there was a 14.3% loss to follow-up over the course, it was equally allocated between the groups; and the remainders were followed up for a long period of 6 months. Furthermore, KP score, FFI, FAOS, and SF-36 used in this study are validated scores that effectively represent the physical activities and quality of life of the patients. Second, lack of biomechanical study or a reliable plantar pressure measuring system could attenuate our explanation of functional superiority in TSI group. However, different bending moments between the groups according to the above-mentioned structural analysis could explain the reason. Further biomechanical study of this design is needed to support the results of this investigation. Third, 3 persons in 24 participants (12.5%) dropped out because of the inconvenience of the 3D printed insole. The insole was somewhat inevitably rough and bulky to fit inside the patient’s own shoes that could have led them to give up. An intention to treat analysis was performed but this could have lessened the strength of this study.
The present study assessed the effectiveness of a newly designed TSI compared to TCI in refractory plantar fasciitis. We reaffirmed that semi-rigid insole is effective in plantar fasciitis and showed a non-inferiority of TSI based on VAS. In addition, TSI more rapidly restored the pedal function compared to TCI. We assume that high bending moments in TSI model would have added more power on plantar fascia and have led consequent functional improvements. This newly designed TSI model can not only be effective in deriving better clinical outcomes but also be manufactured for popularization due to its reproducible design.
(DOC)
(DOC)
(DOC)
(SAV)
PONE-D-21-05601
Superior pedal function recovery of newly designed three spike insole over total contact insole in refractory plantar fasciitis; a randomized, double-blinded, non-inferiority study
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Reviewer #1: A randomized controlled noninferiorty clinical trial was conducted to compare VAS scores of the total contact sole (TCS) with a newly designed three-spike insole (TSI). The study results indicated that the experimental design was noninferior to the standard insole design. Improvements over time were noted in both groups.
Minor revisions:
1- Abstract: Rephrase to improve clarity: “Twenty-eight patients were randomized with equal allocation to either TSI or TCI.”
2- Express numerical p-values more precisely, rather than p < 0.0xx.
3- Line 112: Specify the block size used in the randomization.
4- Line 162: Use standard phrasing: “Twenty-eight patients were randomized, with equal probability, to two groups.”
5- For normally distributed variables, summarize with mean and standard deviation. For nonparametric variables, summarize using median, first, and third quartiles.
6- Indicate if any adverse events occurred during the course of the study.
Reviewer #2: The authors conducted a randomized controlled trial comparing the effect of newly designed insole and total contact insole on plantar fasciitis symptoms. Overall, this study seems well-conducted with reasonable designs and results. I have a few comments.
Introduction
In the first paragraph, please include some data from Korea, if available. For example, the prevalence of plantar fasciitis in Korea, economic cost, etc.
The primary aim is to test new spike insole, and yet it is not very clear to me what are the problems or limitations with conventional insoles. Is the problem just the cost and the duration of fabrication? Also, why did the authors come up with the spike, that is why did the authors believe the spiky design would address the limitations of conventional insoles?
The purpose statement needs to be added.
Methods
In the figure 1, please add a side view photo so that readers can see the height of spikes.
Also, by any chance, did the authors have any data from patients' perceive satisfaction for the new insole? If so, please add the results.
Why did the authors use Mann-Whitney? All the variables were non-parametric? Please confirm.
Results
The figure 2 is difficult to understand. What exactly the asterisk represent? Significant difference in the spike insole group or total contact insole? Do the asterisks represent time x group effect or just time effect?
No new figure should be introduced in discussion so please move figure 4 to results section, and describe the results in this section.
Discussion and conclusion seems to be fine.
Reviewer #3: The authors present a well designed and written study evaluating the efficacy of a novel “3-spike” design shoe insert for the treatment of plantar fasciitis recalcitrant to prior treatment.
To evaluate efficacy the authors enrolled 14 patients to each arm of a non-inferiority comparison between standard orthotic device and novel interventional device. Patients were tracked for 6 months and evaluated using multiple validated subjective scoring systems.
The interventional inserts were created using molds of the patient’s feet, and were 3-D printed to match the patient's weightbearing medial arch.
Utilizing prior experience and observational information regarding the nature of the mold the length and position of the medial arch band of the plantar fascia was interpreted and insoles were either made to be A: load bearing along the full length (Control), or B: fitted with three 2cm diameter elevated “spikes” at center point and distal/proximal along the medial band.
Ultimately the authors found the patient's pain and functional capacity were normalized faster utilizing novel design as compared to standard of care design (control). In this regard the author’s conclude this novel technique to be at minimum non-inferior and likely superior to standard of care.
The authors chose to craft booth insoles using similar methodology to control for variations in design other than the interventional modification. The authors state their believed limitations of this study regarding limited treatment group size and lack of biomechanical or pressure data to support hypothesis of function and loading on novel device. Despite these limitations the authors have designed and executed a well-developed study with novel implications for clinical management of a frequently encountered condition.
I recommend this article for acceptance with minor grammatical revision and look forward to future work from these authors in this field.
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→ Thank you for your reminder. We have checked listed references once again and they are complete and correct.
Additional Editor Comments:
Thanks for contributing your original study to PLOS One. It was reviewed by three independent reviewers with complementary expertise in podiatric medicine, biomechanics, and wearables. All reviewers agreed that this study has scientific merits but could be improved further and provided excellent comments. These comments should be addressed before I could recommend acceptance of your manuscript for publication in PLOS One.
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Reviewers' comments:
5. Review Comments to the Author
Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)
Reviewer #1: A randomized controlled noninferiorty clinical trial was conducted to compare VAS scores of the total contact sole (TCS) with a newly designed three-spike insole (TSI). The study results indicated that the experimental design was noninferior to the standard insole design. Improvements over time were noted in both groups.
Minor revisions:
1- Abstract: Rephrase to improve clarity: “Twenty-eight patients were randomized with equal allocation to either TSI or TCI.”
→ We thank you for your clarification. We have amended it as you have guided.
2- Express numerical p-values more precisely, rather than p < 0.0xx.
→ We thank you for these very important comments. We have proposed more precise ones as you have commented. (Line 51, 53, 190, 192, 195)
3- Line 112: Specify the block size used in the randomization.
→ We thank you for these pertinent comments. We used four block randomization and added it as you have recommended. (Line 103)
4- Line 162: Use standard phrasing: “Twenty-eight patients were randomized, with equal probability, to two groups.”
→ We thank you for your clarification. We revised it as you have recommended. (Line 154)
5- For normally distributed variables, summarize with mean and standard deviation. For nonparametric variables, summarize using median, first, and third quartiles.
→ We thank you for this perceptive comment. We added standard deviation of each value right after mean value. (Line 158-160)
6- Indicate if any adverse events occurred during the course of the study.
→ Thank you for your comment. There was no adverse effect except for the dropped cases as we described in CONSORT flowchart. We specified the absence of adverse event (Line 197)
Reviewer #2: The authors conducted a randomized controlled trial comparing the effect of newly designed insole and total contact insole on plantar fasciitis symptoms. Overall, this study seems well-conducted with reasonable designs and results. I have a few comments.
Introduction
In the first paragraph, please include some data from Korea, if available. For example, the prevalence of plantar fasciitis in Korea, economic cost, etc.
→ Thank you for your comment. Unfortunately, there was no study on prevalence of plantar fasciitis in Korea. However, we added the information of the economic cost in Korea in accordance with National Health Insurance Service. (Line 63-65)
The primary aim is to test new spike insole, and yet it is not very clear to me what are the problems or limitations with conventional insoles. Is the problem just the cost and the duration of fabrication? Also, why did the authors come up with the spike, that is why did the authors believe the spiky design would address the limitations of conventional insoles?
The purpose statement needs to be added.
→ Thank you for your pertinent question. As you have mentioned again, the conventional insoles are quite expensive and take time for customized production. However, we focused on that partially arch supporting structured insole could have a comparable load distribution effect on plantar fascia. Moreover, we postulated that if it has stimulation effect on both ends of fascia, the fascia releasing effect could be maximized. That is why we initially designed the three-spike insole. This design has the merit over conventional TCI on that the three spikes can be easily located uniformly along the plantar fascia. It can be applied to the insoles commonly used in the market with the effect of fascial stretching, saving time and money compared to a TCI and thus allowing mass production of therapeutic insole with the above design. However, the purpose does not contain the exact content as you pointed. We revised it. (Line 82)
Methods
In the figure 1, please add a side view photo so that readers can see the height of spikes.
→ Thank you for your recommendation. We added the lateral view of each insole in Fig 1.
Also, by any chance, did the authors have any data from patients' perceive satisfaction for the new insole? If so, please add the results.
→ Thank you for your question. Unfortunately, we did not check the patient reported satisfaction scale for each insole.
Why did the authors use Mann-Whitney? All the variables were non-parametric? Please confirm.
→ We thank you for your perceptive comment. We used Mann-Whitney and Fisher’s exact test conservatively because many but not all values showed non-parametric distribution.
Results
The figure 2 is difficult to understand. What exactly the asterisk represent? Significant difference in the spike insole group or total contact insole? Do the asterisks represent time x group effect or just time effect?
→ We are grateful for you pointing out this ambiguity. We guess you are pointing Figure 3. Captions might have insufficient explanation. Individual asterisk points significant difference between the groups. And the bar indicates the overall improvement from baseline in both groups. We removed the asterisk over the bar since it was confusing.
No new figure should be introduced in discussion so please move figure 4 to results section, and describe the results in this section.
→ Thank you for your recommendation. We stated the calculation of bending moments at the end of the Material and Methods section (Line 127-128) and moved the figure and results to the Result section. (Line 169-180)
Discussion and conclusion seems to be fine.
Reviewer #3: The authors present a well designed and written study evaluating the efficacy of a novel “3-spike” design shoe insert for the treatment of plantar fasciitis recalcitrant to prior treatment.
To evaluate efficacy the authors enrolled 14 patients to each arm of a non-inferiority comparison between standard orthotic device and novel interventional device. Patients were tracked for 6 months and evaluated using multiple validated subjective scoring systems.
The interventional inserts were created using molds of the patient’s feet, and were 3-D printed to match the patient's weightbearing medial arch.
Utilizing prior experience and observational information regarding the nature of the mold the length and position of the medial arch band of the plantar fascia was interpreted and insoles were either made to be A: load bearing along the full length (Control), or B: fitted with three 2cm diameter elevated “spikes” at center point and distal/proximal along the medial band.
Ultimately the authors found the patient's pain and functional capacity were normalized faster utilizing novel design as compared to standard of care design (control). In this regard the author’s conclude this novel technique to be at minimum non-inferior and likely superior to standard of care.
The authors chose to craft booth insoles using similar methodology to control for variations in design other than the interventional modification. The authors state their believed limitations of this study regarding limited treatment group size and lack of biomechanical or pressure data to support hypothesis of function and loading on novel device. Despite these limitations the authors have designed and executed a well-developed study with novel implications for clinical management of a frequently encountered condition.
I recommend this article for acceptance with minor grammatical revision and look forward to future work from these authors in this field.
→ We are sincerely grateful for your compliments. We are preparing the subsequent large cohort study and hope to introduce it to you in the future.
Submitted filename:
Superior pedal function recovery of newly designed three spike insole over total contact insole in refractory plantar fasciitis; a randomized, double-blinded, non-inferiority study
PONE-D-21-05601R1
Dear Dr. Shim,
We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.
Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.
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Bijan Najafi
Academic Editor
PLOS ONE
Additional Editor Comments (optional):
Thanks for your efforts in addressing the initial voiced concerns raised by reviewers. One of the reviewers voiced additional concern. However, since this concern is minor, to avoid further delay in the review process I recommend acceptance of your manuscript with condition that this concern is addressed in revising your proof.
Reviewers' comments:
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Reviewer #1: (No Response)
Reviewer #2: All comments have been addressed
Reviewer #3: All comments have been addressed
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Reviewer #1: Yes
Reviewer #2: Yes
Reviewer #3: Yes
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Reviewer #2: Yes
Reviewer #3: Yes
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The
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Reviewer #2: No
Reviewer #3: Yes
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Reviewer #2: Yes
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6. Review Comments to the Author
Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)
Reviewer #1: Line 151: Clarify how the non-inferiority test was used. Specifically state the hypothesis it tested.
Thoroughly proofread the manuscript to ensure proper grammar.
Reviewer #2: I thank the authors for addressing my comments. The manuscript looks good. I have no additional comments.
Reviewer #3: Thank you for contributing your original study to PLOS One & making revisions as described by reviewers and editors. After further review of revised materials I recommend acceptance of your manuscript for publication in PLOS One, and look forward to further work from this group.
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Reviewer #2: No
Reviewer #3: No
PONE-D-21-05601R1
Superior pedal function recovery of newly designed three spike insole over total contact insole in refractory plantar fasciitis; a randomized, double-blinded, non-inferiority study
Dear Dr. Shim:
I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department.
If your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact
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on behalf of
Dr. Bijan Najafi
Academic Editor
PLOS ONE