Developmental changes in straight gait in childhood

Saori Miyagishima; Hiroki Mani; Yui Sato; Takahiro Inoue; Tadayoshi Asaka; Naoki Kozuka

doi:10.1371/journal.pone.0281037

Peer Review History

Original SubmissionJuly 25, 2022
7 Sep 2022 Decision Letter - Laura-Anne Marie Furlong, Editor PONE-D-22-20977Developmental changes in straight gait in childhood aged 3-10 yearsPLOS ONE Dear Dr. Mani, 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 Oct 22 2022 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. 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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 ******** 2. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: I Don't Know Reviewer #2: Yes ****** 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: No ****** 4. 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 ****** 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: The aim of this paper was to investigate the age related changes in, or development of, straight gait. The authors used goal index and actual progress index to examine and quantify this. The authors state they developed both indices but it is not clear if the P-index is as previously used in studies? I have concerns regarding the G index as a measure of stability. The p-index makes sense and is a measure of body sway from the direction of progress. The G-index than also incorporates deviation between the direction of progress and the target direction. The authors conclude that pace and stability may contribute to the g-index. However, as mentioned by the authors this measure also "reflects the ability to accurately focus on the target...". This potentially incorporates a large array of variables that have not been considered, some of which may also change with age (attention, ability to follow commands, eye-sight, other distractions in the room etc..). Its not clear from the Methods what instructions were given, how definite these instructions were and what the target was. All of this may impact of the g-index. it is also not clear what this index adds in comparison to just looking at the deviation of one, appropriate VICON marker from the A-P axis for example? The findings in terms of the p-index confirm previous findings that stability is reached at about age 7. Other points: Abstract: Line 30: typically developing might be better than normally developing Line 39: CV not defined on first use Introduction Line 59: Need a reference for statement in first sentence Line 69: Spell error- 'clearly' Line 77 and line 69: I think 'meandering gait' and 'straight gait' need to be more clearly defined and then use one term consistently (if they are same thing?) Methods: more information needed on instructions and gait procedures given the young population and that walking towards target is one of the measured variables. How much instruction? What target? etc.. The middle 4 meters was recorded but then 2m was used for defining straight. Why only 2/4 and which 2? Line 159: HC is presumably heel-contact but needs to be defined on first use Line 195: don't think SD is defined on first use Table 3: DEfine SV in legend (or table). p<0.05 is shown for differences compared to adult group but not clear if there were differences between other groups also or not? Table 4: difficult to follow with all abbreviations and full variable names could easily be included Discussion Line 282: Am not sure it can be said that SV,SW etc contribute to the XCOM variables? They correlate with them which is different. This is maybe a bigger point that needs discussion and is a concern. The two XCOM variables are correlated with a host of other variables all (or at least many) of which are possibly age related so a correlation is not surprising and not sure what it tells us? If XCOM-G and XCOM P were correlated with height for example there may well be a correlation but that just reflects that both change with age/growth? Reviewer #2: Developmental changes in straight gait in childhood aged 3-10 years This is an interesting piece of research which explores meandering gait in childhood and adds more data to the growing field of children's gait biomechanics. I would however recommend some re-positioning of the article in terms of the introduction and rationale to make the justification of the research clearer. Positioning and rationale of the study The specificity of this statement to Japan sold be introduced in the first sentence. This also requires further referencing to justify the latter statement, as does the prevalence of low birth weight and it’s relationship to meandering gait. The link between DCD and meandering gait is confusing – is this research driven and justified by children with DCD or those with meandering gaits? The inclusion criteria suggest that those with typical gait development were included only and therefore this meandering gait is typical in younger ages and not driven by birth weight or DCD, but just related to age and typical development. The second paragraph of the introduction appears to be method heavy as opposed to introducing the topic. In it’s current format I am not sure that the introduction fits the rest of the manuscript, more references and description of typically developing gait and the development of stability would feel like it introduces the topic and additionally adds rationale to the participants and age groups being compared. The purposes and hypothesise are confusing, particularly purpose 2. Methods The methods are generally clear and provide enough detail to be repeatable. The use of the XCOM measures for a whole trial (multiple gait cycles) as opposed to within step appears to be different to the intended use by Hof (2005) and Hallemans et al. (2018), this is not clear within the introduction and has not been fully justified within the manuscript. The descriptions of the variables XCOMg and XCOMp describe an integral, however this is not apparent in Figure 1. It looks like you have tried to take a single point in time as an example, but the figure could be improved and/or described properly. Furthermore the ‘Goal axis’ should be added to this figure along x = 0. The latter descriptions of these indies on line 277-279 are far clearer than any earlier description so I would suggest using this terminology for the method and the figure to support the understanding of the terms. The variables were defined over a period of 2 m with at least 2 gait cycles recorded: How were these selected from the 6 m walkway? Due to the evident range in COM position and XCOM over the gait cycle (from figure 1), should the number of gait cycles analysed for each individual have been standardised? Results, discussion and conclusions The Results section is clear with well-presented tables, but would benefit from a statement of results prior to the table introduction. Again the discussion section would benefit from an introductory sentence or two which summarise the study findings prior to a sub-heading. Line 257: is this supported by both of these variables or XCOMg only? I don’t think the second and third hypothesis are addressed directly in the discussion. The statement which concludes your paper: “The two indices presented in this study are effective parameters for evaluating meandering and postural stability during gait”. This feels like it requires further justification and presentation of data. To link with the introduction, gait which is defined as meandering should have been assessed and defined using your two parameters to compare to gait which isn’t meandering. Minor comments: Line 115: suggest ‘reduces to’ Line 117: ‘involved’ doesn’t make sense her as a term Line 119: what are control mechanisms? Line 132: who provide written consent? The guardian or the child? Line 158: two gait cycles per trial or in total? Line 220: I don’t think a % is an appropriate level and this should be reported as a decimal. Line 258: please clearly define which age groups this statement is true for. Table 1: sex should read ‘male’ or ‘female’ Table 3: check title – Figure 1 title should define the two factors fully in the title. ****** 6. 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: No 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". 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Revision 1
17 Oct 2022 Author Response We thank the reviewers for the meticulous review of our manuscript and the thoughtful comments. We have tried our best to address all the points raised. We have provided point-by-point responses to the reviewers’ comments. In the manuscript, the modified parts are shown in red. Response to Reviewers: Reviewer #1: The authors state they developed both indices but it is not clear if the P-index is as previously used in studies? I have concerns regarding the G index as a measure of stability. The p-index makes sense and is a measure of body sway from the direction of progress. The G-index than also incorporates deviation between the direction of progress and the target direction. The authors conclude that pace and stability may contribute to the g-index. However, as mentioned by the authors this measure also "reflects the ability to accurately focus on the target...". This potentially incorporates a large array of variables that have not been considered, some of which may also change with age (attention, ability to follow commands, eye-sight, other distractions in the room etc..). Its not clear from the Methods what instructions were given, how definite these instructions were and what the target was. All of this may impact of the g-index. it is also not clear what this index adds in comparison to just looking at the deviation of one, appropriate VICON marker from the A-P axis for example? Response: We deeply appreciate the valuable comments of the reviewer. As far as we know, there is no previous research focused on the P index, but we believe that this should be a completely novel index. The G index is as described in the manuscript and is based on previous research. As you suggest, the G-index also incorporates the deviation between the direction of travel and the direction of the target, and is influenced by various factors. We have modified the purpose and hypothesis of this research more clearly (Line 102), and added detailed instructions to the methods section (Line 127). It is clear that various factors are involved in postural control. Therefore, it is required to evaluate straight progress including that element. We believe that it is not possible to consider various factors of attitude control by simply looking at the deviation of one suitable VICON marker from the AP axis. other points: Abstract: Line 30: typically developing might be better than normally developing Response: Thank you for your advice. As you pointed out, I changed it to “typically”. (Line 30) Line 39: CV not defined on first use Response: Thank you for pointing this out. As you said, I defined the first "CV". (Line 39) Introduction Line 59: Need a reference for statement in first sentence Response: Thank you very much for your pointing out. I decided that this part was not appropriate and deleted it. Line 69: Spell error- 'clearly' Response: Thank you very much for your pointing out. This has been corrected accordingly. (Line 63) Line 77 and line 69: I think 'meandering gait' and 'straight gait' need to be more clearly defined and then use one term consistently (if they are same thing?) Response: Thank you for your appropriate remarks. Since "meandering" and "straight" are confusing, I decided to use the term "straight gait" as a unified term. Methods: more information needed on instructions and gait procedures given the young population and that walking towards target is one of the measured variables. How much instruction? What target? etc.. Response: The explanation was certainly inadequate. As you pointed out, I added detailed instructions to methods (line 127). The middle 4 meters was recorded but then 2m was used for defining straight. Why only 2/4 and which 2? Response: Due to the experimental environment, we had no choice but to limit the analysis range for defining straight movement to 2m. The reason is that the maximum range for recording all marker data of all participants was 2m. I wrote about it in Line 148. Line 159: HC is presumably heel-contact but needs to be defined on first use Response: Thank you for your advice. ``Heel contact'' was added. (Line 150). Line 195: don't think SD is defined on first use Response: This has been defined in introduction section (Line 93). Table 3: DEfine SV in legend (or table). p<0.05 is shown for differences compared to adult group but not clear if there were differences between other groups also or not? Response: Thanking for pointing that out. It is indicated as “Step velocity” in the table. In addition, I added below the table that there was no difference from the non-adult group. Table 4: difficult to follow with all abbreviations and full variable names could easily be included Response: Thanks to your point, I defined the abbreviations other than SI and CV in the table, and defined SI and CV below the table. Discussion Line 282: Am not sure it can be said that SV, SW etc contribute to the XCOM variables? They correlate with them which is different. This is maybe a bigger point that needs discussion and is a concern. The two XCOM variables are correlated with a host of other variables all (or at least many) of which are possibly age related so a correlation is not surprising and not sure what it tells us? If XCOM-G and XCOM P were correlated with height for example there may well be a correlation but that just reflects that both change with age/growth? Response: Thank you for your very important remarks. Our previous study (Mani et al., reference [7]) reported that individual gait variables such as SV and SW were not perfectly correlated with age, indicating different developmental characteristics. We thought that by examining the relationships between these five gait functional domains and the straight gait indices could help us understand the kind of control functions that are required for straight gait. In this study, we showed that the ability for straight gait develops with age (Table 3) and further showed the gait variables that are associated with two indices of straight gait (Table 4). Reviewer #2: About positioning and rationale of the study Response: Thank you for your very useful remarks. Certainly, the link between DCD and meandering gait is confusing. So, we decided to remove the content of the first paragraph of the original manuscript from the revised manuscript because it was less relevant to this study. Instead, we clarified the motivation for this study by citing previous studies on the development of gait stability. The purposes and hypotheses are confusing, particularly purpose 2. Response: Thanks for pointing it out. It's certainly confusing, so I changed the hypothesis from 3 to 2 (Line 103). Then, I revised the two hypotheses so that they were clearly stated in the discussion (Line 262 and 282). Methods The use of the XCOM measures for a whole trial (multiple gait cycles) as opposed to within step appears to be different to the intended use by Hof (2005) and Hallemans et al. (2018), this is not clear within the introduction and has not been fully justified within the manuscript. Response: Thank you for pointing this out. This study was carried out using a modified method, referring to references 6 and 7. Since there may be an effect of arranging it a little, I added it as a research limit (line 330). The descriptions of the variables XCOMg and XCOMp describe an integral, however this is not apparent in Figure 1. It looks like you have tried to take a single point in time as an example, but the figure could be improved and/or described properly. Furthermore the ‘Goal axis’ should be added to this figure along x = 0. Response: Thank you for your advice. It is true that Fig1 is difficult to understand, so I corrected Fig1 and added the explanation of the figure, referring to what you pointed out. The latter descriptions of these indies on line 277-279 are far clearer than any earlier description so I would suggest using this terminology for the method and the figure to support the understanding of the terms. Response: Thank you for your advice. Based on your advice, I decided to add the corresponding part to the introduction. (Line 80) The variables were defined over a period of 2 m with at least 2 gait cycles recorded: How were these selected from the 6 m walkway? Due to the evident range in COM position and XCOM over the gait cycle (from figure 1), should the number of gait cycles analysed for each individual have been standardised? Response: Thank you for your advice. The maximum range for recording all marker data of all participants was 2m. We were concerned that the measurement range (distance) of each subject would change if we used the walking cycle; hence, we decided to analyze by setting the distance to 2 m. This has been described in Line 148. Normalization was done for each individual's COM height. Results, discussion and conclusions The Results section is clear with well-presented tables, but would benefit from a statement of results prior to the table introduction. Again the discussion section would benefit from an introductory sentence or two which summarise the study findings prior to a sub-heading. Response: Thank you for your useful advice. I added a short heading on line 220 as per your advice. Line 257: is this supported by both of these variables or XCOMg only? I don’t think the second and third hypothesis are addressed directly in the discussion. The statement which concludes your paper: “The two indices presented in this study are effective parameters for evaluating meandering and postural stability during gait”. This feels like it requires further justification and presentation of data. To link with the introduction, gait which is defined as meandering should have been assessed and defined using your two parameters to compare to gait which isn’t meandering. Response: Thank you for your comment. The first sentence of the discussion indicated two variables. However, I thought the original text was difficult to understand, so as you pointed out, I decided to consider each hypothesis separately. As shown earlier, the hypotheses were changed into two (Line 103), and the discussion was modified to link with the introduction (Line 262 and 283). Minor comments: Line 115: suggest ‘reduces to’ Response: Thank you for your advice. I changed it as you pointed out (line 104). Line 117: ‘involved’ doesn’t make sense her as a term Response: Thank you for pointing this out. As you pointed out, I corrected the sentence to be appropriate for deletion. (Line 105). 119: what are control mechanisms?　 Response: Thanks for your questions. This has been changed to “Control function.” This indicates an element related to postural control during walking, as shown by Mani et al. Line 132: who provide written consent? The guardian or the child? Response: Thank you for pointing this out. The guardians provided consent. This has been added accordingly (Line 120). Line 158: two gait cycles per trial or in total? Response: Thanks for your questions. It is two gait cycles per trial were recorded. Line 220: I don’t think a % is an appropriate level and this should be reported as a decimal. Response: Thank you for pointing this out. We have corrected this accordingly (Line 216). Line 258: please clearly define which age groups this statement is true for. Response: Thank you for pointing this out. We have clearly defined the relevant age group. (Line 263). Table 1: sex should read ‘male’ or ‘female’ Response: Thank you for pointing this out. We have corrected this accordingly (Table 1). Table 3: check title Response: Thank you for pointing this out. I made some changes to the title. Figure 1 title should define the two factors fully in the title. Response: Thank you for pointing this out. I have modified Figure 1 and its description. Attachments Attachment Submitted filename: Response to Reviewers.docx https://doi.org/10.1371/journal.pone.0281037.r002
23 Nov 2022 Decision Letter - Laura-Anne Marie Furlong, Editor PONE-D-22-20977R1Developmental changes in straight gait in childhoodPLOS ONE Dear Dr. Mani, 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 Jan 07 2023 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: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols. We look forward to receiving your revised manuscript. Kind regards, Laura-Anne Marie Furlong Academic Editor PLOS ONE Journal Requirements: Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice. [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: All comments have been addressed ******** 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: I Don't Know 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: Yes Reviewer #2: No ****** 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: This sentence in Introduction is not clear- 103 changes in straight gait and the control mechanisms involved. We hypothesized that: 104 (a) straight gait reduces to at younger ages and reaches the adult level around the age 105 of 7 years [4]; is it "ability to walk in straight line is reduced at younger ages"? Methods 139 the same position. After practicing the task several times, the results were recorded 140 five times Was a mean of teh 5 trials then used for analysis or one representative? Reviewer #2: We acknowledge the substantial amendments to the manuscript made by the authors and think that the paper is far improved, but would recommend some further changes and clarification prior to publication. Introduction: Line 58-59: This still feels a little undefined and not fully justified as a reference to a theme/topic. Also the justification that there is not enough research feels very subjective. To link and lead onto the following paragraph there at least needs to be a description of the relevance of DCD to meandering gait. Line 86-88: this sentence needs rewording: I am not sure what it is trying to say, it doesn’t make sense. Line 104: hypothesis 1 needs rewording as ‘reduces to at younger’ does not make sense Line 128: ‘calling’ would be better described as encouraging them forwards Line 129: was the walking path painted/drawn on the floor? Line 160/161: I think earlier this was defined as the position of the researcher? It may be better defined as the start and end point of the walking bouts? This might be better used throughout as opposed to the current reference as ‘start position to parents’ such as line 173 also. Line 219: these statements feel highly cemented in the outcomes of the statistical tests and without any real consideration of magnitude of effect or what is a meaningful difference. IN Table 3 we can see substantial differences in XCOMG between Adults and 7-8 and 9-10 and I think this should be considered. Discussion: The XCOMG variable has been discussed with relevance to other data and studies but this has not been compared or contrasted in terms of numerical outcomes in the discussion. In particular Hallemans Please check the references: I am not sure that they align; Hallemans for example is 6 in the list and 7 in the text. ****** 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: No 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. https://doi.org/10.1371/journal.pone.0281037.r003
Revision 2
22 Dec 2022 Author Response Response to Reviewers We thank you for your peer review and comments on our second submitted manuscript. We have done our best to address all points raised. Provided a point-by-point response to the reviewer's comments. In the manuscript, the changed parts are shown in red. Response to Reviewers: Reviewer #1: This sentence in Introduction is not clear- changes in straight gait and the control mechanisms involved. We hypothesized that: (a) straight gait reduces to at younger ages and reaches the adult level around the age of 7 years [4]; is it "ability to walk in straight line is reduced at younger ages"? →Thank you for your advice. We decided the first half of this sentence was confusing, so we fixed it. (Line 114) Methods the same position. After practicing the task several times, the results were recorded five times Was a mean of the 5 trials then used for analysis or one representative? →Thank you, you are right. We have added an explanation to Line 152. Reviewer #2: Introduction: Line 58-59: This still feels a little undefined and not fully justified as a reference to a theme/topic. Also the justification that there is not enough research feels very subjective. To link and lead onto the following paragraph there at least needs to be a description of the relevance of DCD to meandering gait. →Thank you for your advice. We discussed the topic of walking in children with developmental disorders, and deepened the content so that the purpose of this research would be linked. (Line 58-69) Line 86-88: this sentence needs rewording: I am not sure what it is trying to say, it doesn’t make sense. →Thank you for pointing this out. We fixed the wording. (Line 96-98) Line 104: hypothesis 1 needs rewording as ‘reduces to at younger’ does not make sense →Thank you for your advice. We decided the first half of this sentence was confusing, so we fixed it. (Line 114) Line 128: ‘calling’ would be better described as encouraging them forwards →Thank you for pointing out. I have corrected it as you pointed out. (Line 138) Line 129: was the walking path painted/drawn on the floor? →Yes, you are correct. I added a photo (Fig 1). (Line 157-159) Line 160/161: I think earlier this was defined as the position of the researcher? It may be better defined as the start and end point of the walking bouts? This might be better used throughout as opposed to the current reference as ‘start position to parents’ such as line 173 also. →Thank you for pointing out. Sorry, this is the part I forgot to correct in the first review. I decided to define the start and end points of the walk as you suggested. (Line 150-151, 177 and 190) Line 219: these statements feel highly cemented in the outcomes of the statistical tests and without any real consideration of magnitude of effect or what is a meaningful difference. IN Table 3 we can see substantial differences in XCOMG between Adults and 7-8 and 9-10 and I think this should be considered. →Thank you for pointing out. Certainly, the values in the 7-8 years group and the 9-10 years group were still small compared to the adult group, which may be due to the growth process. However, it is true that there were no statistically significant differences between the 7-8years group compared to the adult group. So I mentioned it in the discussion, not the result. Discussion: The XCOMG variable has been discussed with relevance to other data and studies but this has not been compared or contrasted in terms of numerical outcomes in the discussion. →Thank you for your advice.Based on the results of comparison by age, we added what kind of abilities can be acquired by what age (Line 306-309). In particular Hallemans Please check the references: I am not sure that they align; Hallemans for example is 6 in the list and 7 in the text. →Thank you for pointing this out. We rechecked and revised the reference list and manuscript. Attachments Attachment Submitted filename: Response to Reviewers.docx https://doi.org/10.1371/journal.pone.0281037.r004
17 Jan 2023 Decision Letter - Dimitrios Sokratis Komaris, Editor Developmental changes in straight gait in childhood PONE-D-22-20977R2 Dear Dr. Mani, 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. An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org. If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org. Kind regards, Dimitrios Sokratis Komaris, Ph.D Academic Editor PLOS ONE Additional Editor Comments (optional): Both reviewers have made editorial comments, kindly review them below and make appropriate corrections before submitting your final manuscript. Discussion; page 16; line 305: "Thus, this index expresses one of the ability to walk straight." This is not clear. Would/should it be better written as: "Thus, this index expresses one COMPONENT of the ability to wall straight." And Line 66 remove or reword ‘it shows’ Figure 3 add years to x axis. 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: All comments have been addressed ******** 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: 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: Thank you for the work in addressing comments to date and eh manuscript is significantly improved and clear. I have one remaining query regarding a sentence which is unclear and needs to be clarified: Discussion; page 16; line 305: "Thus, this index expresses one of the ability to walk straight." This is not clear. Would/should it be better written- "Thus, this index expresses one COMPONENT of the ability to wall straight." Reviewer #2: The authors have responded to the revisions and added further description to the introduction which helps identify the rationale for the work and other research in this field. The method is now also clearer with further description and a figure which supports the interpretation of the text and helps reproducibility. Minor comments which could be amended to support the readability: Line 66 remove or reword ‘it shows’ Figure 3 add years to x axis ****** 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: No Reviewer #2: No ******** https://doi.org/10.1371/journal.pone.0281037.r005
Formally Accepted
31 Jan 2023 Acceptance Letter - Dimitrios Sokratis Komaris, Editor PONE-D-22-20977R2 Developmental changes in straight gait in childhood Dear Dr. Mani: 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 onepress@plos.org. If we can help with anything else, please email us at plosone@plos.org. Thank you for submitting your work to PLOS ONE and supporting open access. Kind regards, PLOS ONE Editorial Office Staff on behalf of Dr. Dimitrios Sokratis Komaris Academic Editor PLOS ONE https://doi.org/10.1371/journal.pone.0281037.r006

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