PONE-D-20-05316

The arch support insoles show benefits to people with flatfoot on gait process time, plantar pressure and contact area

PLOS ONE

Dear Dr Chen-Yi Song,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

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Gianluca Vernillo, Ph.D.

Academic Editor

PLOS ONE

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Reviewers' comments:

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Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Partly

Reviewer #2: Partly

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2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: No

**********

3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

**********

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Reviewer #1: Yes

Reviewer #2: Yes

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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: General comments:

I would like to thank the editor for inviting me to review the manuscript entitled “The arch support insoles show benefits to people with flatfoot on gait process time, plantar pressure and contact area”. This study compared various plantar pressure measurements while walking on three slopes and while wearing two different types of insoles. Please find below my comments, which may aid the authors with submitting a revised version of their manuscript.

- I think that the authors made a great attempt to link their variables of interest to measures of importance to people with flatfeet. However, the authors attempted to link simple plantar pressure variables to mobility and walking benefits without describing what is meant by these terms. I would recommend to clearly state what is meant by the terms “mobility” and “benefits” and how improvements in mobility look like.

- One of the authors’ main conclusions, namely that increased midfoot area relative to total area in the arch-support insole is representative of the restoring of a “normal” arch is, in my opinion, an incorrect statement. If the loaded midfoot area increases, it means that more of the midfoot is in contact with the ground. This would mean that the foot is actually in a more flattened position. I would strongly recommend revising the statements made upon these findings.

- Lastly, I would recommend removing figure 1, as it does not provide valuable information to the understanding of the methods of this paper. I would also recommend providing all units within tables 1-4 instead of including them in the table headings. The units in table 1 are unclear. Also, the p-values and Cohen’s d effect sizes should be provided for all comparisons in all tables.

Specific comments:

Line 43: In the introduction of the main text, you have not mentioned any previous study investigating increased pressure at the hip, knee, or ankle joints in people with flat feet; but you talk about it in the background section of the abstract. Please either introduce the observed changes at the hip, knee, and ankle joints from the previous studies in the introduction of the main text or delete this statement from the background section of the abstract. Also, I would strongly recommend to change the wording from “pressure on the lower back, hip, …” to “loading on the lower back, hip, …”.

Line 44: “… and risk serious damage to these joints …”. You have not provided any evidence for this statement in the main text. Please either remove this statement from the abstract or elaborate on this and provide references in the main text.

Line 51: Please consider rephrasing the sentence to “The significance level α was set to 0.05.”

Lines 52-58: Please include Cohen’s d effect sizes for the reported comparisons. Also, please reorder the results section so that you always mention the same insole first in your comparisons. This would make it easier for the reader to follow your findings.

Line 60: It is unclear how your reported findings “provide benefits in mobility”. You cannot make this statement with the results that you presented in the above section unless you clearly demonstrate how these variables are related to benefits in mobility.

Line 74: “… suffers from rigid the flatfoot …”: remove “the” from the sentence

Line 80: Please include a reference at the end of the sentence.

Lines 83-84: This sentence suggests that flatfoot can result in damage to internal organs and the brain. This is incorrect. Please remove this statement from the manuscript.

Line 87: Please include a reference at the end of the sentence.

Line 91: I think using the term “cure rate” is inappropriate for two reasons: 1) leg internal rotation and leg length discrepancy is not a “disease” and therefore cannot be “cured”, 2) wearing insoles does not “cure” anything, it may reduce excessive leg internal rotation or offset leg length discrepancy. Please replace the term “cure rate” with a more appropriate term.

Line 95: the peak vertical ground reaction force is not the propulsion force. They are probably related to each other but they are not the same. Therefore, please remove “(i.e., propulsion)” from the sentence.

Lines 102-104: this sentence is the same as the sentence before that. Please remove this sentence and include its references to the previous sentence.

Lines 106-108: this is not a hypothesis. Clearly state how wearing the arch-insole will affect your variables of interest.

Line 112: remove “with” from the sentence.

Line 116: Consider rephrasing the sentence to: “A priori sample size calculation was performed using GPower (Company, City, Country), …”.

Line 118: Why were the means and standard deviations for the medial-lateral COP used to perform the sample size calculations if these are not the variables of interest in your study?

Line 122: the plural of “index” is “indices”

Line 123: “… were considered to have the flatfoot …”. Remove “the” from the sentence.

Lines 125-127: the review board that approved this study is not affiliated with any institution of any of the authors. Could you please elaborate on that?

Line 134-135: Please consider rephrasing the sentence to: “The insole consists of 960 individual pressure measuring sensors.”

Lines 142-143: Please consider rephrasing the sentence to: “Each subject performed a 3 min warm-up period on the treadmill at self-selected pace.”

Lines 143-147: In one sentence you say that participants walked on all slopes one after the other with a 6 min break in between slopes. In the next sentence, however, you state that walking on different slopes was performed on different days. Those are contradicting statements. Which one is true?

Line 151: How was the hardness measured exactly. More information is needed.

Line 158: “gait process time”. This variable is typically referred to as “stance time” or “ground contact time”. Please consider changing this throughout the manuscript to not confuse the reader.

Line 161: remove “each” from the sentence.

Line 177: Please include a reference for how Cohen’s d effect sizes were calculated.

Line 185: was there a difference in stance times for the other slopes? Even if not, please include a sentence stating so and also include the p-value and effect size for the comparison.

Lines 190-212: Please change the order of reporting your comparisons. Sometimes you first mention the arch-support insole and other times you first mention the flat insole. Please pick one insole that you will always mention first in your comparisons. This would confuse the reader less.

Lines 210-211: please include your p-values and ES right after the slope condition.

Lines 217-219: you said that the arch-support insole shortened the time of each gait cycle. This is incorrect. A gait cycle goes from the heel strike of one foot to the heel strike of the same foot. Your findings showed, however, that the stance times were altered. Please revise.

Line 218: you state that mobility was improved. None of your variables of interest is a measure for mobility. At least you did not make good enough of a case that a variable you investigated actually represents mobility. Please provide more evidence that stance times are a legitimate measure for mobility or remove this statement from the paper.

Line 220: you state that the arch-support insole absorbed the shock associated with the foot contacting the ground. Again, this is a pure speculation and you have not provided any evidence that this is the case. Please provide the evidence or delete this statement from the manuscript.

Lines 238-239: I do not understand this sentence. Please elaborate what you want to say here.

Lines 244-245: It is only a speculation that wearing arch-support insoles will “restore a normal, elastic arch in people with flatfoot, …”. Please clearly state that this is only a speculation or include a reference that has shown this in the past. Also, what is a “normal” arch?

Lines 247-249: You cannot make this statement. You have not demonstrated why reducing peak pressures would be a benefit for people with flatfoot. Please make a better case of how you link peak pressure to substantial benefits in people or remove this statement.

Lines 256-258: How does wearing an arch-support insole restore a “normal”, elastic arch? What do you speculate is the mechanism behind it? Again, what is “normal”? Perhaps, you should not use this term.

Lines 258-265: You have not assessed arch deformation in any way in this study; yet, you discuss the windlass mechanism and how the arch may or may not collapse with these insoles. I would strongly recommend highlighting that these are speculations, only, or remove the entire paragraph from the manuscript.

Lines 269: how would the forefoot play a crucial role in the braking during downhill walking if all participants were striking with the heel? The forefoot will mainly still be in the air during the braking period of the stance phase. Therefore, the forefoot cannot contribute to the braking at all. Again, this is a speculation because you have not assessed forefoot motion. Please remove this statement from the paper.

Lines 276-278: If the area of the midfoot increases relative to the total area, then the foot is flatter compared to when the midfoot area is lower compared to the total area. This is also called the arch index (Cavanagh, 1987). Your conclusion, therefore, does not make sense. Please revise.

Line 281: remove “make” from the sentence.

Lines 293-294: you cannot make the statement that wearing the arch-support insole provided many benefits in mobility. You have not provided clear reasoning as to why this would be the case. Please remove this statement from the paper.

Reviewer #2: The purpose of this study was to determine if persons with flatfoot (i.e., per planus) changed the pressure distribution across the foot while walking uphill, downhill, or on even ground in flat or arch supported insoles. The study indicated that the “gait process time”, the pressure distribution, and contact area were different in the flat or arch support insoles, but seemed to be dependent on the walking condition. I believe there needs to be some improvements in the analysis and interpretation before this manuscript is ready for publication.

I have a number of minor comments, but those may become irrelevant after the major comments are addressed. Here are my major comments.

1. The statistics need to change. There was a comparison of insole condition across different levels of incline. The results seemed to indicate that the variables that were different across insole conditions seemed to be dependent on the level of incline. With this observation in mind, the researchers should re-run the statistics on each dependent variable and instead of conducting multiple uncorrected t-tests, they should conduct a two way repeated measures ANOVA with factors INCLINE (uphill, level, downhill) and INSOLE (flat, arch support). This will indicate if there is an interaction effect for the measured pressure and gait variables.

2. Why did you restrict you sample to only females, particularly when the condition seems to be more common in males? Please provide an explanation why there wasn’t any males.

3. Please provide an explanation as to why your static arch index was representative of flatfoot. My understanding is that flat foot would have something to do with the proportion of the foot that is or is not in contact with the ground in a loaded or unloaded condition. What does the narrowest and widest part of the foot have to do with the arch collapsing or per planus?

4. Where was the pressure insole placed relative to the insoles (i.e., underneath or above)? Please provide an explanation why you used on placement method over the other.

5. How much of the results were due to hardness/stiffness of the insole versus it having arch support or not? For example, there was a difference in midsole hardness in the arch support condition and this condition also presented with an increase contact area. The same results applies to the forefoot area such that the harder condition showed increase contact area.

6. Please change “gait process time” to stance time that would be more consistent with the literature.

7. Please present the data across the dominant and non-dominant leg. If in one leg there was higher peak pressure and lower peak pressure in the other, this would average out to no change in pressure. I don’t think your averaging method avoids discrepancies.

Please incorporate these changes and adjust the discussion accordingly. Once those comments are addressed, I will be able to provide more feedback on the minor, or major, comments that remain.

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Reviewer #1: Yes: Sasa Cigoja

Reviewer #2: No

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files to be viewed.]

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Attachments

Attachment

Submitted filename: PONE-D-20-05316 - Comments.docx

PONE-D-20-05316R1

The arch support insoles show benefits to people with flatfoot on stance time, plantar pressure and contact area

PLOS ONE

Dear Dr. Chen-Yi Song,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

Please submit your revised manuscript by Jul 18 2020 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

• A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.
• A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.
• An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: http://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols

We look forward to receiving your revised manuscript.

Kind regards,

Gianluca Vernillo, Ph.D.

Academic Editor

PLOS ONE

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: (No Response)

Reviewer #2: (No Response)

**********

2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: No

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

**********

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: I have only one question left to the authors addressing my first comment of the first round of revisions:

I think that the authors made a great attempt to link their variables of interest to measures of importance to people with flatfeet. However, the authors attempted to link simple plantar pressure variables to mobility and walking benefits without describing what is meant by these terms. I would recommend to clearly state what is meant by the terms "mobility" and "benefits" and how improvements in mobility look like.

Authors' response:

Thank you for your comment. We have changed the term "mobility" to gait speed. Studenski, et al. (2011) indicated that longer stance time reflects lower gait speed that is predictive of increased mortality in middle-aged and elderly people. The shortened stance time found in the current study was speculated to increase the gait speed because of wearing the arch-support insole. In addition, we have removed this statement from conclusion that "wearing the arch-support insole provided many benefits in mobility". Please refer to lines 242-247. These results imply that wearing an arch-support insole provides benefits in the shortened stance time and generation of propulsion force to the big toe while walking on uphill and level surfaces and to the metatarsals 2-4while walking on the level surface. We have stated these in abstract and conclusion section. Please refer to lines 61-63 and 306-310.

Reference:

Studenski S, Perera S, Patel K, Rosano C, Faulkner K, Inzitari M, et al. Gait speed and survival in older adults. Jama. 2011; 305(1): 50-58. doi:10.1001/jama.2010.1923

New question:

How can gait speed be increased if your participants were walking at a set speed on a treadmill? According to your methods in line 141, your participants were walking at 0.75 m/s. I would hope that their gait speed did not change between conditions. The stance times may have changed but this would infer a change in step frequency or swing time as well. Was this the case?

Reviewer #2: Thank you to the authors for making some of the requested changed. The authors will still need to address the following comments:

1. Please provide the rationale as to why only females were recruited in the text of the manuscript under the methods section.

2. You did not provide a sufficient statement of the hardness of the insoles as a limitation. You need to be specific. You should be stating that the arch support insole did have higher hardness in the midsole and the flat insole was harder in the forefoot and the heel. This difference in stiffness could be a confounding variable to the results in the study and therefore, you cannot conclude that the differences were due to differences in hardness or the presence vs absence of an arch support

3. Your purpose statement reads “the purpose of this study was to investigate the effects of the arch-support insoles on stance time, cadence, peak pressure, and contact area of the foot with the ground while walking uphill, downhill, and on a level surface, respectively.” In the discussion, you did not provide much explanation of the interaction effects that were found. You need to perform a post-hoc analysis on the interaction effects to determine the location of the interaction effect. For example, stance time had an interaction effect across insole and slope. It appears that this difference occurred in level walking, but not uphill and downhill walking. This needs to be determined with the post-hoc analysis and then an interpretation should be provided in the discussion. Please complete this type of analysis and interpretation for each interaction effect.

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7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: Yes: Sasa Cigoja

Reviewer #2: No

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

PONE-D-20-05316R2

The arch support insoles show benefits to people with flatfoot on stance time, plantar pressure and contact area

PLOS ONE

Dear Dr. Song,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

Please make sure to properly address the reviewer's #2 comment. Your revised manuscript must not be open to the criticism that potentially could add confusion. Addressing and properly characterizing your sample is an essential prerequisite. Furthermore, according to the PLOS ONE's policy and the reviewer's #1 comment, please make your data publicly available.

Please submit your revised manuscript by Aug 30 2020 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

• A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.
• A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.
• An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: http://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols

We look forward to receiving your revised manuscript.

Kind regards,

Gianluca Vernillo, Ph.D.

Academic Editor

PLOS ONE

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

Reviewer #2: (No Response)

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2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: No

Reviewer #2: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

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: Thank you for addressing my comments. I would recommend that the paper is accepted for publication once the set of data that is needed to reproduce the findings and conclusions of this study are made publicly available (e.g., online data repository) as per PLOS Data policy.

Reviewer #2: You have addressed two of my comments thoroughly and one partially. For comment 1 with respect to recruiting only females, you need to state this reason explicitly in the methods section after you mention that only females were recruited. In its current form, this selection criteria is unclear. Please insert a comment at the beginning of the methods section that addresses this choice.

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Reviewer #1: No

Reviewer #2: No

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The arch support insoles show benefits to people with flatfoot on stance time, plantar pressure and contact area

PONE-D-20-05316R3

Dear Dr. Song,

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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Kind regards,

Gianluca Vernillo, Ph.D.

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #2: All comments have been addressed

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2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #2: Yes

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3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #2: Yes

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4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #2: Yes

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5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

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 #2: (No Response)

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7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #2: No