Functional Electrical Stimulation of the Lateral Knee Muscles Can Reduce Peak Knee Adduction Moment during Stepping: A Pilot Study

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The paper systematically analyzes the application effectiveness of FES in improving biceps brachii muscle function recovery in stroke patients. The introduction extensively and systematically reviews existing research on FES in the fields of rehabilitation and exercise physiology, providing readers with background understanding and research motivations. The methods section details the experimental design and methodologies used, including the application of FES and measurement techniques, enabling readers to understand how the experiments were conducted and data collected. However, the paper has some shortcomings. It fails to discuss in detail potential confounding factors that may affect experimental results, such as participants' physiological differences and exercise states, which could impact result interpretation and generalizability. The discussion section lacks an in-depth exploration of the clinical significance of the experimental results, future research directions, or practical applications, thereby lacking in prospects and stimulating further research interests. In conclusion, I would recommend the authors focus on enhancing the depth of result interpretation, controlling potential confounding factors, and further revising the discussion to improve the academic quality and readability of the paper.

Specific comments are shown below:

1. The introduction mentions some background information and related research but does not clearly state the specific research question or objective of the current study. It is recommended to clearly articulate the specific objectives and problems to be addressed by the current study at the end of the introduction.

2. The introduction contains repetitive or unnecessarily detailed information, which may distract the reader. For example, the presentation of some research results that have already been mentioned can be simplified, focusing instead on the innovation and necessity of the current study.

3. Lines 50-53: “Biomechanically, alterations in the normal knee kinematics and kinetics…”. Lines 59-61: “Considerable literature provided strong evidence…”. The reviewer acknowledges these views, however there is a lack of relevant literature to support them. The authors may consider citing the following relevant literature for further clarification: (1) Accurately and effectively predict the ACL force: Utilizing biomechanical landing pattern before and after-fatigue (https://doi.org/10.1016/j.cmpb.2023.107761); (2) New insights optimize landing strategies to reduce lower limb injury risk (https://doi.org/10.34133/cbsystems.0126).

4. More details on how to randomize different FES conditions should be provided in the Methods section to ensure the reliability and reproducibility of the results.

5. Lines 204-211: Please clarify that this is an incorrect expression.

6. Suggest providing more detailed background information and data for comparison with results from other studies in the Discussion section. For example, clarify what 'functional activity differences' in Xu et al.'s study entail, and why these differences might lead to varying research outcomes.

7. The authors are advised to thoroughly explore possible reasons for statistically non-significant results and consider the impact of these findings on the overall conclusions of the study.

8. The authors are encouraged to further discuss the issue of small sample size in the KOA group, specifically detailing how inadequate sample size can influence study outcomes. Additionally, consider exploring individual differences more comprehensively, analyzing variations in FES response among different individuals and their underlying reasons.

9. While potential benefits of FES and elliptical machine training are mentioned, practical application suggestions are lacking. It is recommended to include practical clinical application recommendations, detailing how these findings can be translated into clinical practice to assist patients.

Comments on the Quality of English Language

no

Author Response

Please see the second attachment that was submitted, as we made further revisions to the formula that was used in the manuscript and included them in the second letter. Sorry for the inconvenience. 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Dear editor, I would like to thank you for your kind invitation to review the article entitled “Functional Electrical Stimulation of the Lateral Knee Muscles Can Reduce Peak Knee Adduction Moment During Stepping .

The authors aimed to investigate the effects of FES applied to the biceps femoris and lateral gastrocnemius on knee joint moments during elliptical stepping by healthy adults and individuals with KOA.

First of all, I would like to congratulate the researchers for their efforts research idea.

Since the number of cases included in the study was small, it can be called a pilot study.

I suggest that they write the introduction a little more summarized, making it simpler for readers.

The authors included 16 healthy and 5 individuals diagnosed with knee osteoarthritis. However, when the characteristics of the cases are analyzed, it is presented in Table 1 that the age group of healthy participants is younger and BMI values are lower. In addition, there were more male participants in the healthy group. I think that these differences may change the interpretation of the results.

The authors' sentence below may not be concluded by the results of this study.

“Potentially, the combination of multiple forces and loads modifying approaches  known to reduce pKAM may slow down the progression of osteoarthritic changes. “

I think that the authors' study will contribute a lot to rehabilitation processes, and I think that their study will be very valuable. Increasing the number of individuals diagnosed with OA or redesigning the study by including individuals of similar age and clinical characteristics will provide us with data to interpret the correct results.

From this point of view, I suggest that the discussion section should also be rewritten.

Comparing the outcomes of patients with OA and healthy controls can also provide us with important information

Author Response

Please see the attachment. 

Author Response File: Author Response.pdf