Spatiotemporal Gait Variability in Children Aged 2 to 10 Decreases throughout Pre-Adolescence

Round 1

Reviewer 1 Report

Review to the biomechanics-2709835

Dear, Author(s)

Congratulations! You have achieved another scientific milestone through your dedication and hard work. This study was to analyze the development of gait dynamics and gait variability in children ranging from 2-10 years old. The study aims to understand how children’s gait changes as they grow older and to determine if there is a pattern of maturation and stability in their gait. The study also aims to provide insights into neurological issues and gait pathology by focusing on the maturation of children’s gait and gait variability. The gait dynamics were measured by analyzing the variability of stride time and stride length and gait variability was also measured both linear measures (mean, standard deviation, coefficient of variation) and nonlinear measures (sample entropy, detrended fluctuation analysis) of gait variability.

Specific comments

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Major comments.

1. In terms of human body mechanics, the ankle joint is compensated for by the knee and hip joints, with the knee joint also compensated for by the hip joint. For example, when walking, if there is a rock underfoot, the foot adjusts through movements such as inversion, eversion, dorsiflexion, and plantar extension, to continue movement without falling or affecting gait variables such as gait velocity, stride length, cadence and so on. If the impact of the rock cannot be compensated for by the movements of the foot and ankle, the knee and hip joints will compensate. Thus, walking is influenced by ground reaction forces and vectors. On the other hand, Vicon estimates the axis of the hip joint based on the pelvis and the axis of the knee joint based on the movement of the hip joint. In other words, Vicon estimates the movement of lower limb joints using body vectors, which is contrary to human body mechanics. Therefore, when performing gait analysis with Vicon, the placement of the marker is of utmost importance and must remain consistent during each measurement period. As shown in the provided photo, a marker was placed on the clothes. If the clothes move, the marker's position will change. The researcher must first clarify how this potential issue was corrected.

2. Secondly, how was the child's gaze treated during measurement? The position of a subject's head while walking directly affects gait characteristics. A more detailed explanation is needed on how this aspect was managed consistently throughout the experiment.

3. Regarding your research results, why were gait variables chosen? It is common to consider kinetic and kinematic characteristics as variables of gait. Yet, you compared standard deviation, coefficient of variation, sample entropy, etc., as single variables. Please elaborate on the reasoning behind this choice and its clinical significance.

Minor comments.

Introduction

Your introduction currently cites only four references, none of which are from the last 10 years. Additionally, approximately two-thirds of the fourth paragraph and all of the fifth paragraph lack citations. Typically, an academic study of around 3,000 words would include about 12 references in the introduction alone. It is recommended to add more recent literature, specifically from the past 5 to 10 years, to your bibliography. Furthermore, if the original works are not crucial to this study, you should consider replacing the four cited works with more contemporary references from within the last decade.

Methods

There is a difference between sex (biologic) and gender (social) so be clear what you measured, use the right terminology and be consistent in using sex because you were evaluating biologic differences/traits, gait dynamics.

The name of SPSS 18.0 version is PASW, and this version was produced by SPSS, not IBM.

Please use the symbols (Footnotes) in the Table in the order of general use based on the researchers’ agreement.

^{*   †   ‡   §   ‖   ¶   #   **   ††   ‡‡}

Discussion

Typically, an academic study of around 3,000 words would also include about 12 references in the discussion section. It is also recommended to add more recent literature, specifically from the past 5 to 10 years, to your bibliography.

Your research is undoubtedly of high quality. The research topic suggests that significant effort was needed to collect and process the data. However, a more detailed explanation of your methods and efforts is recommended. Please show your strong job ethics.

Author Response

Thank you for taking the time to review my manuscript. I appreciate the feedback and criticisms you have provided and hope to have addressed all of your concerns with my submission. Please see the responses in the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Thank you for the opportunity to review this manuscript, my considerations on the manuscript are described below:

Abstract:

- Well written and clear.

Introduction:

- Authors must place the article in the Biomechanics rules, where citations are in Vancouver style, using subscript numbers in brackets for citations.

- The introduction is well written, with a logical and temporal sequence of the study problem.

- The objective at the end of the introduction is very clear.

Methods:

- What is the design/type of the study?

- How was the sample recruited? Where was the sample recruited from? Was there a calculation to estimate the sample size, or is it a convenience sample? The authors need to further detail how the sample for this study was recruited.

- Authors must inform the exact location where the markers were placed on the child, so that this method can be a reproductive method for other future investigations.

- It would be interesting to include photos of these markers on the volunteer's body, outside the treadmill, with photos in front, back and profile views, to clearly demonstrate where the markers were placed. This increases the chances of the article being cited and this method being used in other studies.

- The image of the child on the treadmill needs to be named Figure 1, and it needs a title in its footer. What the authors call Figure 1 would actually be Figure 2, and the current Figure 2 needs to be changed to Figure 3.

Results:

- Suitable for what the authors proposed.

Discussion:

- I suggest authors divide the discussion into topics, this helps the reader understand where the part of the text they are looking for is. As the authors evaluated several gait parameters, I believe it will make the discussion cleaner for those who read the study, dividing the discussion by topics, in relation to the parameters evaluated.

- I missed in the discussion an expansion of the discussion on the maturation of motor control systems and gait performance in children. However, it would be worthwhile to better explain which motor control systems changes occur with age and how these changes could justify the findings. I believe it would further justify the results of the study, giving the authors theoretical-scientific support for the findings found.

Conclusion:

- Adequate and in accordance with the results found.

References:

- Old and outdated. The most current reference in the study is from 2005. I strongly suggest that the authors update the study references.

Author Response

Thank you for taking the time to review my manuscript. I appreciate the feedback and criticisms you have provided and hope to have addressed all of your concerns with my submission. Please see the responses in the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Thank you for your revised manuscript. 

Reviewer 2 Report

Dear editor, thank you for the opportunity to review this article once again, all my considerations were accepted and modified by the authors in the text, with the exception of one, in which the authors placed the citations in parentheses, for example: (2-5) and in fact, according to Biomechanics standards, citations are in brackets, example: [2-5].

Therefore, I believe that the authors did a good job and that the article should be accepted for publication, with the condition of correcting the references throughout the article, so I decided to accept the article after minor revisions.