A Biomechanical Comparison of Therapeutic Footwear and Athletic and Low-Cost Generic Shoes: Effects on Plantar Pressure, Lower Extremity Kinematics, and Kinetics

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors Dear authors, I have read this manuscript with pleasure and it suited my research and clinical interests. This study aimed to investigate the effects of two types of Orthofeet therapeutic footwear in comparison to low‐cost generic as well as participant’s own athletic shoes on plantar pressure and lower extremity kinematics and kinetics. The manuscript was organized well. The results, discussion, and conclusion are consistent with the purpose of the study. The authors fully realise the limitations of this work. Despite the well-organised paper, section particularly Methods require need clarification. Below are detailed comments that the authors should address while revisiting the paper to improve its quality and overall scientific impact.

• What was the specific method for selecting the study participants?
• Who placed the markers? What was their experience level? How many researchers took part in the study? Please report on your lab's quality assurance of accuracy and reliability of marker placement. Please also describe the calibration procedures used to establish the laboratory coordinate system as well as the collection of a static trial for each participant.
• Line 120: “For each footwear condition, participants walked at a self‐paced speed 120 across the walkway (~10 m long) three times. “ Please define exactly how many gait cycles were used and average for each participant; was it the same for all participants? Why only three attempts?
• Sticking markers on the shoes makes some doubts. However it is recommended to add a note in the Discussion section that authors are aware that the foot kinematics are not perfectly determined because the markers are attached to the footwear instead of the defined anatomical points of the subject's body as the model assumes.
• There are doubts about sticking markers on the shoes. It is clear that for the time being there is no other way to make such measurements. The authors should include in the Discussion section that they are aware that the kinematics of the foot are not perfectly determined because the markers were pasted on the footwear and not at defined anatomical points on the subject's body as the model assumes.
• The methodology should be explained in detail to facilitate replicability.
• A figure with the measuring device would help to understand the measurement.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Introduction

Line 33-38: The focus of the study was on the comparison of therapeutic footwear with regular shoes and athletic shoes, but the greater emphasis on diabetic foot ulcers in the previous section may lead readers to believe that the study was conducted on diabetic patients, when in fact the study was conducted on a healthy population. This needs to be clarified in the introduction. In addition, this research is concerned with the biomechanical differences between therapeutic shoes and other shoes, rather than the preventive effect on diabetic foot ulcers. This also needs to be articulated clearly.The following order of writing can be referred to: first, a brief description of the dangers of diabetic foot ulcers and what are the performance needs of patients for footwear? Is it full or partial cushioning under the foot, or? What kind of biomechanical properties do therapeutic shoes have that are different from typical athletic shoes to prevent ulcers?

Lines 39-49: The second paragraph needs to be supplemented with the sole and insole characteristics of therapeutic shoes to improve the coherence of the preceding and following text.

Lines 69-76: What are biomechanical benefits? How do you define biomechanical benefit? Is it greater foot dorsiflexion or less plantar pressure in walking? Are there references? Most importantly what is the hypothesis of this study?

Methods

Line 80-82: Was ethical review approval obtained for this study? Please write the approval number. Does the small sample size affect statistical efficacy? Details of the screening of subjects are suggested to be added, was a structural assessment of the foot carried out to ensure that the foot characteristics of the subjects did not affect the results of the study as high arches and flat feet etc. may affect gait. The subjects in this study were healthy adults and the therapeutic shoes were primarily intended for people with diabetic feet, will this limit the applicability of the findings?

Lines 139-140: The study defaults to the right side as the dominant side, but does not explain how the dominant side of the subject is determined? Since some individuals may be dominant on the left side, a unilateral analysis may affect the generalizability of the findings. It is recommended that additional clarification be provided on how the dominant side was determined and that the limitations of analyzing only the right side be discussed.

Lines 167-170: Pearson's correlation is not explained (is the data normally distributed?). Pearson's correlation is appropriate for normally distributed data; if the data are significantly skewed, Spearman's correlation may be needed.

Discussion

Lines 265-283: The study found that therapeutic shoes reduced heel pressure but increased bunion pressure without delving into the possible long-term effects of this change in pressure distribution on foot health, such as whether it might increase bunion loading leading to potential injury.

References

13, 14, and 30 formatting needs to be adjusted.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The article entitled “Biomechanical Comparison of Therapeutic Footwear, Athletic, and Low‐Cost Generic Shoes: Effects on Plantar Pressure and Lower Extremity Kinematics” is well-written and easy to follow. However, there are some issues that have to be solved before it can be published. The main concerns are the small sample size, the big range of ages, and the reduced time given to get used to the footwear.

Why did the authors decide to report the peak plantar pressure? The PPP is subjected to more variability, the mean plantar pressure should be considered.

The authors must indicate how the sample population was calculated and justify why the range of ages was too high (18-48 years).

In the introduction section, line 69, the authors have to include “$US dollars”. Moreover, the authors have to justify why these shoes are costly, compared to what? Include the reference where the cost was consulted.  

How do the authors validate that the participants did not present foot disorders or pain?

It is known that the insoles play an important role in gait kinematics, then, the insole images of the four types of shoes should be included. Then, the reader can better understand how they contribute to the gait kinematics and kinetics.  

The authors must include an image of a participant with the placed markers. Also, indicate how the markers were attached, double-sided tape or Velcro. This could affect the relative motion of the marker and the skin of the participant. Furthermore, how much time was given to the participants to get used to the shoes, this could affect the outcomes and conclusions. Five minutes is not enough to allow the proprioceptive system to adapt to the different footwear. This system has been adapted to their own shoes for a long time, which is the reason they presented the highest comfort rate.

A comparison of the kinematic and kinetic parameters has to be performed on both lower limbs (left and right) or at least report that the differences were not significant.

The materials and weight of the three types of shoes should be included in a Table. Then the reader could better understand the effect of shoes on the kinematics, kinetics, and plantar pressure distribution.

It is known that the therapeutic shoes for diabetic people are designed considering a bigger ball girth circumference, this is to give more space and comfort to the feet. How were the shoe sizes assigned to the participants? Do the authors take measurements of the foot anthropometry of the participants?  

In the conclusion section, line 323, which are those biomechanical benefits, please be more specific.

The manuscript presents some identical phrases from other sources, please rewrite them. Please revise the iThenticate report.

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

Although the manuscript has been revised, several methodological issues remain unresolved.
First, in the conclusion, the claim that therapeutic shoes provide a biomechanical advantage over low-cost shoes needs further clarification. Is it truly an advantage? Given that this study examines immediate effects, whether the observed differences align with the study’s background discussion requires further consideration.
Additionally, the conclusion states that therapeutic shoes can be replaced with regular athletic shoes, but the study does not specify the characteristics of these regular shoes. This lack of detail does not adhere to basic scientific research principles.
Furthermore, is there a validated reference for the shoe comfort assessment? The participant group has not been clearly defined. The manuscript also seems to lack details on the sampling frequency of the force plate and plantar pressure measurement system, as well as the definitions of key parameters.
In the statistical methods section (line 195), the explanation is unclear. What exactly is being conveyed? How are the statistical differences between MANOVA and ANOVAs determined? Additionally, details regarding the SPSS software version and settings used should be provided.

Author Response

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Reviewer 3 Report

Comments and Suggestions for Authors

No more comments. 

Author Response

We would like to express our sincere gratitude for your positive feedback.

Round 3

Reviewer 2 Report

Comments and Suggestions for Authors

Although the manuscript has generally addressed the previous concerns, as I previously noted, the results do not align well with the stated research objectives and hypotheses. I believe this reflects a fundamental issue with the experimental design. Moreover, I did not find any results related to gender differences as mentioned (see Line 199).

In addition, I recommend that the authors re-evaluate the alignment between the study design and the stated hypotheses, especially since the results do not effectively support the research objectives. Potential limitations and alternative interpretations should be clearly addressed. Furthermore, although sex differences were mentioned as a variable in the study, no corresponding results or discussion were provided. This inconsistency should be resolved by either including relevant data and analysis or explaining why this aspect was not addressed, in order to maintain the overall coherence and completeness of the study.

 

Moreover, what were the original sampling frequencies for the Vicon system and the AMTI force plates? Were all raw data subjected to any form of data smoothing or filtering? If so, what was the cutoff frequency used? Additionally, is there a relevant reference for the method used to calculate joint moments?

Author Response

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