Relationships between Body Weight Support and Gait Speed Parameters and Muscle Activity and Torque during Robot-Assisted Gait Training in Non-Neurological Adults: A Preliminary Investigation
Round 1
Reviewer 1 Report (New Reviewer)
Relationships between body weight support and gait speed parameters and muscle activity and torque during robot-assisted gait training in non-neurological adults: A preliminary investigation
Generral comments
Hard to review initial introduction in pdf format and no lines
Introduction
Line 25 statistically significant, ranging from r = 0.480 to -0.510, p < 0.05) omit parenthesis. Is the range really + to _???
Line 27 anterior activation data correlations existed, respectively not clear.
Lines 29-31. How do you know the muscle activation patterns were due to the RACT BWS? Did you compare your findings to the subjects walking without the RACT BWS? Also, you only gathered information on normal healthy subjects and this needs to be included in the conclusion
Lines 129-130
Were all of the Pearson Correlation Coefficients considered independent of each other? If not, you may need to divide your alpha ( 0.05) to represent multiple testing..
Table 1 only describes 17 subjects but methods indicate you recruited 20 subjects
Table 3
How can correlations of 0.132, 0.268, -0.61,-0.168, 0.213, 0.126 be statistically significant? These are not clinically meaningful correlations. 0132 only explains 1.7% of the variance.
Study Limitations
You need to mention that some of the correlations were minimal . Even though they were statistically significant, they made minimal contributions to explaining the variance in the relationships between the variables.
Conclusions
The conclusions at the end of the manuscript are more accurate than the conclusion in the abstract. The abstract conclusion needs to be more accuracte
Author Response
Thank you for your sincere review. Quality of the manuscript has been improved greatly.
Author Response File: 
Author Response.docx
Reviewer 2 Report (Previous Reviewer 1)
This is the second version of the same manuscript that I reviewed on 4/30/2022. Therefore, I reiterate my previous reservations:
20 volunteers participated in the research. There were 9 females in this sample. The gender breakdown was not included in the analysis of the results. Overall, however, the number is small despite the results in the test for statistical power (G * Power).
If the Authors hope that the results of their experiment can be transferred to people with disabilities, it should be immediately emphasized that the signal from surface EMG of the lower extremity muscles differs significantly between healthy people and people with nervous system dysfunction.
In the event of damage to the neuromuscular system, the gait of these patients takes a different form than that of healthy people. In the case of disabled people, the main task is to be able to move around with the use of individual motor abilities. Correctness of gait according to the pattern of healthy people is irrelevant for these patients.
It should be taken into account that biosignals (EMG) from skeletal muscles recorded by surface electrodes are poorly reproducible and very differentiated between individuals during free walking. For this reason, among others, the values “r”of Pearson's correlation coefficients in Table 3 are very low. All significance only at the level of p <0.01. Is there a mistake in the asterisks? In the caption of Table 3 there is a reference to p <0.05.
Lack of information about the normality of the distributions. With such a small number and large diversity of people in terms of sex, age and body morphology parameters, it was better to use the Spearman correlation.
Even on a treadmill of 1 km/h for a healthy person, the walking speed is too low. Normally the speed is about 3-4 km/h.
Author Response
Thank you for your sincere review. Quality of the manuscript has been improved greatly.
Author Response File: Author Response.docx
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
Round 1
Reviewer 1 Report
- The problem of using the exoskeleton for upright standing and gait support in patients with paresis of the lower limbs belongs to the modern trend of supporting the rehabilitation process.
- Scientific works in this field are divided into those aimed at stimulating the neuromuscular structures to stimulate the free walking reflex.
- The second goal of the exoskeleton experimenters was general rehabilitation of patients, aimed at improving muscle strength, intestinal peristalsis, body stabilization and others.
- For this reason, the discussed problem in this experiment should be considered modern and clinically useful.
- There are, however, a few issues that need clarification, namely:
- Twenty community dwelling individuals (10 men and 10 women) participated in the study. If the Authors hope that the results of their experiment can be transferred to people with disabilities, it should be immediately emphasized that the signal from surface EMG of the lower extremity muscles differs significantly between healthy people and people with nervous system dysfunction. For this reason, functional electrostimulation (FES) is still not used to control the movement of the lower limbs in the gait of people with neurological problems.
- In the event of damage to the neuromuscular system, the gait of these patients takes a different form than that of healthy people. In the case of disabled people, the main task is to be able to move around with the use of individual motor abilities. Correctness of gait according to the pattern of healthy people is irrelevant for these patients.
- It should be taken into account that biosignals (EMG) from skeletal muscles recorded by surface electrodes are poorly reproducible and very differentiated between individuals during free walking. For this reason, among others, the values “r”of Pearson's correlation coefficients in Table 3 are very low.
- In lines 128 it is stated that "statistical significance was set as p <0.05". This contradicts the statistical significance given in the description of Table 3.
- It is unclear what "Experimental number vs 4 muscle" means. What exactly is this correlation about in Table 3?
- Lack of information about the normality of the distributions. With such a small number and large diversity of people in terms of sex, age and body morphology parameters, it was better to use the Spearman correlation.
- Even on a treadmill of 1 km/h for a healthy person, the walking speed is too low. Normally the speed is about 3-4 km/h.
Author Response
Response to Reviewer 1 Comments
Point 1: Twenty community dwelling individuals (10 men and 10 women) participated in the study. If the Authors hope that the results of their experiment can be transferred to people with disabilities, it should be immediately emphasized that the signal from surface EMG of the lower extremity muscles differs significantly between healthy people and people with nervous system dysfunction. For this reason, functional electrostimulation (FES) is still not used to control the movement of the lower limbs in the gait of people with neurological problems.
Response 1: this is included in the limitation.
Point 2: In the event of damage to the neuromuscular system, the gait of these patients takes a different form than that of healthy people. In the case of disabled people, the main task is to be able to move around with the use of individual motor abilities. Correctness of gait according to the pattern of healthy people is irrelevant for these patients.
Response 2: This has been elaborated in the limitation
Point 3: It should be taken into account that biosignals (EMG) from skeletal muscles recorded by surface electrodes are poorly reproducible and very differentiated between individuals during free walking. For this reason, among others, the values “r”of Pearson's correlation coefficients in Table 3 are very low.
Response 3: We understand that not all of r values are indicating high correlation. However, some show moderate correlation, and this has been discussed in the discussion section.
Point 4: In lines 128 it is stated that "statistical significance was set as p <0.05". This contradicts the statistical significance given in the description of Table 3.
Response 4: Statistical significance is set at p <0.05, however, some of the results showed higher statistical significance p <0.001, and this has been identified in Table 3.
Point 5: It is unclear what "Experimental number vs 4 muscle" means. What exactly is this correlation about in Table 3?
Response 5: The experimental numbers are described in Table 2, which is related to gait speed and BWS.
Point 6: Lack of information about the normality of the distributions. With such a small number and large diversity of people in terms of sex, age and body morphology parameters, it was better to use the Spearman correlation.
Response 6: I understand that Pearson correlation evaluates the linear relationship between two continuous variables, and Spearman correlation evaluates the monotonic relationship. Kinetic and EMG data are categorized as continuous variables, therefore, I believe Pearson correlation should be used.
Point 7: Even on a treadmill of 1 km/h for a healthy person, the walking speed is too low. Normally the speed is about 3-4 km/h.
Response 7: The maximum gait speed is automatically set according to the individual leg length in the Walkbot. This usually does not exceed 2.3km/h.
Reviewer 2 Report
Congratulations to the authors on the study "Effects of optimal body weight support and gait speed parameters on leg muscle activity during interlimb ankle–knee–hip robotic gait in healthy adults". Overall this is a highly interesting topic that might be beneficial to improve future training regimens.
However there are some aspects to be addressed before considering publication:
Page 3, 38ff please add citation that emphasizes this assumption
Page3, 43ff citation
Page7, delete “Experiments”
Page7/8, add BMI to table 1 for a better overview
Mat.&Methods section – please provide pictures of the experimental setup
Page11,Fig.2 Abbreviations?
Page12,line 230, shank?
Page15,line 297 please rephrase
Conclusion : please provide some suggestions on how the findings can be implemented to improve training
Raw data should be presented - at least as supplementary data
Relatively small participant number
Power analysis?
Author Response
Response to Reviewer 2 Comments
Point 1: Page 3, 38ff please add citation that emphasizes this assumption
Response 1: this has been revised
Point 2: Page3, 43ff citation
Response 2: this has been revised
Point 3: Page7, delete “Experiments”
Response 3: this has been revised
Point 4: Page7/8, add BMI to table 1 for a better overview
Response 4: this has been revised
Point 5: Mat.&Methods section – please provide pictures of the experimental setup
Response 5: this has been revised
Point 6: Page11,Fig.2 Abbreviations?
Response 6: this has been revised
Point 7: Page12,line 230, shank?
Response 7: this has been revised
Point 8: Page15,line 297 please rephrase
Response 8: this has been revised
Point 9: Conclusion : please provide some suggestions on how the findings can be implemented to improve training
Response 9: this has been revised
Point 10: Raw data should be presented - at least as supplementary data
Response 10: raw data is avaiable upon request due to the large number of data set.
Point 11: Relatively small participant number
Response 11: included in the limitation
Point 12: Power analysis?.
Response 12: this has been revised
Reviewer 3 Report
Dear Park et al.,
The manuscript “Effects of optimal body weight support and gait speed parameters on leg muscle activity during interlimb ankle–knee–hip robotic gait in healthy adults” (applsci-1713102) by Park et al. aim to determine the optimal RAGT training parameters (BWS and treadmill speed) for EMG muscle activity and the relationship between EMG muscle activity
and hip and knee torques during RAGT. The topic is interesting, but I think this article should reconsider after proper changes in major revision for publication in Applied Seciences. Some of my specific comments are below:
1. In the abstract section (line 11-32), the authors should add quantitative results rather than only qualitative results.
2. Please change Backgound section (line 37) to Introduction section.
3. Describe the novelty of the article made by the author? From the results of my evaluation, it seems that many similar published works adequately explain what you have raised in the current manuscript related to body weight and speed against gait cycle. If there are something others really new in this manuscript, please highlight it more clearly in the background section (line 37-89).
4. The state of the art and the significance of the current study are not clearly present, the authors should highlight it more advanced in the background section (line 37-89).
5. Can the authors explain the crucial things why the effect of two parameters (body weight and gait speed) needs to be studied during healty adults? Why not unhealthy aduls? Or the effect of person activity level parameter? The reviewer thinks it is more interesting since the literature not explore in-depth about that.
6. Since this manuscript is related to lower extremities and gait, I would encourage and advise the authors to adopt some of the specific additional references related to total hip prsothesis evaluation under gait cycle of healthy adults published by MDPI in the background section (line 37-89) as follow:
• Tresca Stress Simulation of Metal-on-Metal Total Hip Arthroplasty during Normal
Walking Activity. Materials (Basel). 2021, 14, 7554.
https://doi.org/10.3390/ma14247554
7. In the methods section (line 91-234), the authors should add one systematic figure to illustrate the workflow of experimental testing in the present study to make the reader more interested and easier to understand rather than only using dominant text to explain.
8. The author must provide a detailed specification and use condition more detail regarding all tools used in the research carried out so that the reader can estimate the accuracy and differences in the results that the authors describe due to the use of different tools in future studies.
9. In table 1 (line 147) the authors explain about detail sample used on their studies. The Body mass index categories is important to mention based on the reviewer's prespective. I recommended including it.
10. Still related to Table 1, activity level, profession, origin, and other aspects of its subject also affect the results of the investigation, I think the authors should be aware about that.
11. In the Results section (line 236-249), the authors are advised to compare the results they obtain with previous similar/identical studies if it is possible.
12. In the last paragraph before conclusion section (after line 304), the authors should add of one paragraph about the limitations of the presented review.
13. The conclusion (line 306-311) of the present manuscript is not solid. Further elaboration is needed.
14. Further research needs to be explained in the conclusion section (line 306-311).
15. I see some errors on English in some areas of the present manuscript. To improve the quality of English used in this manuscript and make sure English language, grammar, punctuation, spelling, and overall style are correct, further proofreading is needed. As an alternative, the authors can use the MDPI English proofreading service for this issue.
16. In the current form, the authors does not use Applied Sciences, MDPI template. Please make sure the authors have used the Applied Sciences, MDPI format correctly. The authors can download published manuscripts by Applied Sciences, MDPI, and compare them with the present author's manuscript to ensure typesetting is appropriate.
I am pleased to have been able to review the author's present manuscript. Hopefully, the author can revise the current manuscript as well as possible so that it becomes even better. Good luck for the author's work and effort.
Best regards,
The Reviewer
Author Response
Response to Reviewer 3 Comments
Point 1: In the abstract section (line 11-32), the authors should add quantitative results rather than only qualitative results.
Response 1: this has been revised
Point 2: Please change Backgound section (line 37) to Introduction section.
Response 2: this has been revised
Point 3: Describe the novelty of the article made by the author? From the results of my evaluation, it seems that many similar published works adequately explain what you have raised in the current manuscript related to body weight and speed against gait cycle. If there are something others really new in this manuscript, please highlight it more clearly in the background section (line 37-89).
Response 3: We understand that similar research/article has been published in the past. Nevertheless, the type of RAGT exoskeleton varies (i.e. Lokomat and Walkbot) and their systems have differences as to how training parameters are controlled. Our research as its novelty in a fact that no such research has been done in a Walkbot. Also, variation in studied muscle groups exists.
Above contents has been added in the manuscript.
Point 4: The state of the art and the significance of the current study are not clearly present, the authors should highlight it more advanced in the background section (line 37-89).
Response 4: Last paragraph of introduction section highlights the significance of the study. Also, we believe this point is in line with added contents for point 3.
Point 5: Can the authors explain the crucial things why the effect of two parameters (body weight and gait speed) needs to be studied during healty adults? Why not unhealthy aduls? Or the effect of person activity level parameter? The reviewer thinks it is more interesting since the literature not explore in-depth about that.
Response 5: we understand that healthy adults and adults with neurological deficits obviously have differences in their function and movement patterns. Therefore, this was a baseline study for a future research with adults with neurological deficits. This has been noted in the limitation and conclusion section.
Point 6: Since this manuscript is related to lower extremities and gait, I would encourage and advise the authors to adopt some of the specific additional references related to total hip prsothesis evaluation under gait cycle of healthy adults published by MDPI in the background section (line 37-89) as follow:
- Tresca Stress Simulation of Metal-on-Metal Total Hip Arthroplasty during Normal Walking Activity. Materials (Basel). 2021, 14, 7554. https://doi.org/10.3390/ma14247554
Response 6: We have reviewed the above article and noticed they also discussed about normal walking, however, their discussion is more focused on the type of biomaterials used in THA. In addition, they used full gait cycle as to we divided gait cylces in windows regarding the muscle groups we analyzed.
Point 7: In the methods section (line 91-234), the authors should add one systematic figure to illustrate the workflow of experimental testing in the present study to make the reader more interested and easier to understand rather than only using dominant text to explain.
Response 7: this has been added
Point 8: The author must provide a detailed specification and use condition more detail regarding all tools used in the research carried out so that the reader can estimate the accuracy and differences in the results that the authors describe due to the use of different tools in future studies.
Response 8: We believe all tools used were well described in the method section of 2.1 and 2.2.
Point 9: In table 1 (line 147) the authors explain about detail sample used on their studies. The Body mass index categories is important to mention based on the reviewer's prespective. I recommended including it.
Response 9: this has been revised
Point 10: Still related to Table 1, activity level, profession, origin, and other aspects of its subject also affect the results of the investigation, I think the authors should be aware about that.
Response 10: Those informations are not gathered at the time of data collection, therefore unable to be identified.
Point 11: In the Results section (line 236-249), the authors are advised to compare the results they obtain with previous similar/identical studies if it is possible.
Response 11: This is included in the discussion section.
Point 12: In the last paragraph before conclusion section (after line 304), the authors should add of one paragraph about the limitations of the presented review.
Response 12: this has been revised
Point 13: The conclusion (line 306-311) of the present manuscript is not solid. Further elaboration is needed.
Response 13: this has been revised
Point 14: Further research needs to be explained in the conclusion section (line 306-311).
Response 14: this has been revised
Point 15: I see some errors on English in some areas of the present manuscript. To improve the quality of English used in this manuscript and make sure English language, grammar, punctuation, spelling, and overall style are correct, further proofreading is needed. As an alternative, the authors can use the MDPI English proofreading service for this issue.
Response 15: This manuscript has been reviewed and edited by an editing agency. We will provide a editing certificate upon request.
Point 16: In the current form, the authors does not use Applied Sciences, MDPI template. Please make sure the authors have used the Applied Sciences, MDPI format correctly. The authors can download published manuscripts by Applied Sciences, MDPI, and compare them with the present author's manuscript to ensure typesetting is appropriate.
Response 16: this has been revised
Round 2
Reviewer 2 Report
The quality of the manuscript has been improved, however some aspects still need to be addressed properly. Furthermore answering almost every comment by "this has been revised" is inappropriate. Actions need to be taken on the aspects/comments below. Otherwise the quality has been greatly improved, spell check and partial rephrasing as well as proper formatting are required.
page1, line 68: show not showed
page1, line 69: erase additional ";"
page 2, line 176ff rephrase
page 3, line 203 use lower leg
page 3, line 257ff rephrase, they did not volunteer in this number because of the power analysis, unless I'm mistaken; rahter were 20 participants included given the result of the power analysis
page 7, line 401 reformat
page 8, line 444 lower leg
page 8, line 457 reformat - probably the title of the table below???
Author Response
Thank you for your thorough review.
Author Response File: Author Response.docx
Reviewer 3 Report
Dear Park et al.,
After carefully reading the author's revised manuscript entitled "Effects of optimal body weight support and gait speed parameters on leg muscle activity during interlimb ankle–knee–hip robotic gait in healthy adults" (applsci-1713102) by Park et al., The current manuscript does not provide a significant improvement after major revision with very minimum effort. Also, the authors are failing to address all of the fundamental critical comments regarding their manuscript, especially number 3, 5, 10, and 16.
Regarding substantial, there are some crucial flaws in this manuscript. The participant involved in this study is very small which would make biased and invalid results because of the gait from every person is very difference in each other. We need many participants involved with each person measuring at least 10 times to see the average/mean gait pattern.
Still related to the participants involved, current research does not use clear criteria which can lead to unreliable results. Based on the results of internal measurements conducted by the reviewer's research team and several published literature, it is explained that many aspects affect gaits, such as height, weight, body mass index, activity level, profession, and origin. It was found that people with other similar specifications, but with different origins (Japanese and Western) had very different gait patterns. However, this important point is not highlighted by the author in his manuscript.
The author's approach by conducting research aimed at unhealthy people by measuring healthy people is clearly wrong. In the current manuscript, measurements should be made with adults with neurological deficits. And do not forget the two points that have been stated previously, related to the number of participants and the specifications of the participants involved. The reviewer places great emphasis on the participant involved because this greatly affects the results obtained in the study. If the participant involved is incorrect, then it can be ascertained how serious flaws the result will be. If this article is finally accepted, this manuscript is very dangerous for the scientific community, especially gait and related research area.
Also, the originality, state of the art, research novelty, and research significance are questioned and can be said to be non-existent because they have been achieved by published articles based on my best knowledge and expertise in this field. One of which the author has consciously mentioned is scientific literature from Lokomat and Walkbot. This is exacerbated by the author's inability to make a constructive explanation regarding the contribution of the current manuscript by systematically explaining the research gap.
The author also did not use the Applied Science, MDPI template correctly. Whereas in the previous review report I have highlighted this. Unfortunately, this is not taken seriously by the author. In the first version, the authors do not use the template at all. And after revision, the template is not used correctly. The authors can look at the title of the present manuscript, where uppercase and lowercase is not appropriate. Please download the published version of the applied science manuscript, and the authors can compare it with their manuscript. This clearly shows that the author is not serious in responding to my response to his manuscript. From a basic point of view, the template alone is ignored, what about the quality of the content? you can already guess how mediocre it is.
In the end, after the revision, this manuscript is inappropriate for publication, has a serious flaw, and should not be published.
Best regards,
The Reviewer
Author Response
Thank you for your thorough review.
Author Response File: Author Response.docx
Round 3
Reviewer 3 Report
Thank you to the authors for improving their manuscript in review round 2. I have re-read their manuscript and their responses.
The author's response is clearly a mistake. If the results of the research cannot be improved or enhanced to an appropriate condition, such as the author's explanation that the research has been discontinued. Obviously, this manuscript has very dangerous flaws and should be rejected. This is my second rejection of this manuscript.
Manuscripts deviate from low quality as it is presented by the authors if published would bring to create defects in science and the scientific community. Further improvement by addressing all that I previously criticized is urgently needed, otherwise, the research must be repeated and the current manuscript needs to be improved so that the new research results deserve, as simple as that.
For the third time, I informed the authors about the wrong format, on line 10 of the current manuscript for review round 2, the author's email uses blue with an underline, this is clearly not in accordance with the MDPI template. As I said earlier, from the template alone the author is not serious, what about the substance? It can already be seen how mediocre it is.
The result of my evaluation for this manuscript was rejected, it should not be published. It is lack quality, content, and novelty.
