A Symmetry Evaluation Method, Using Elevation Angle, for Lower Limb Movement Patterns during Sitting-to-Standing†
Round 1
Reviewer 1 Report
The manuscript entitled “Proposal of a symmetry evaluation method for lower limb movement patterns during sit-to-stand using elevation angle” is an important work to study the method to evaluate the improvement of left-right synergy of the impaired lower extremity during STS. However, the manuscript needs to be improved, and much more information about the procedure must be added to allow replication of the study.
Methods :
1. The experimental part needs more detailed description : the demographic indicators of the participants, the location of the experiment, the specific time of the experiment, etc.
2. In line 109, each small picture in Figure 1 should have a more specific description, rather than summary in the overall title.
Discussion :
1. The author should discuss the limitations of the study.
2. The discussion part is too simple, lack of deep thinking. The authors lack the advantages or breakthroughs of this study compared with other studies, or fill the gaps in which field of research. Or the method obtained in the study has a breakthrough contribution to real life.
Conclusion :
1. The authors should refine the importance of research findings and the description of future application scenarios.
2. The conclusions mentioned that the number of participants was too small and MSE did not yield useful conclusions from statistical tests. More explanations or literature support are needed to explain this part in this paper: why such a problem occurs; why research has certain defects, but the research content still has certain theoretical and practical significance; what additional supplements have been made in this study to fill the gaps in this aspect and so on. More detailed descriptions are needed in the article ( which may be added in the discussion section ).
Author Response
■Methods :
- The experimental part needs more detailed description : the demographic indicators of the participants, the location of the experiment, the specific time of the experiment, etc.
<Response>
The physical data of the participants were added as Table.1 on page 3. In addition, details of the experimental location and procedure were added to Chapter 2, "Methods," under "2.2. Experiment" (lines 100-102 and 108-117).
- In line 109, each small picture in Figure 1 should have a more specific description, rather than summary in the overall title.
<Response>
The image in Figure 1 on page 4 was divided into four parts (a) through (d), and explanatory text was added to each figure.
■Discussion :
- The author should discuss the limitations of the study.
<Response>
On pages 12 to 13, lines 337 to 347, the limitations of this study were added within Chapter 4, "Discussion".
- The discussion part is too simple, lack of deep thinking. The authors lack the advantages or breakthroughs of this study compared with other studies, or fill the gaps in which field of research. Or the method obtained in the study has a breakthrough contribution to real life.
<Response>
The advantages and practicality over previous studies were added in Chapter 4, "Discussion" on page 12 (lines 298-312) The greatest advantage of the R-L vector line is the visual ease with which symmetry can be assessed. As noted in the limitations of this study, neurological improvement may be explained by kinematic assessment if measured and compared simultaneously with muscle synergy.
■Conclusion :
- The authors should refine the importance of research findings and the description of future application scenarios.
<Response>
Added a note to Chapter 5, "Conclusion," on page 13, lines 359-371, regarding the significance of the R-L vector line as a symmetry evaluation method. We also added that we are considering the application of the R-L vector line to the walking plane rule, which compresses information into two variables.
- The conclusions mentioned that the number of participants was too small and MSE did not yield useful conclusions from statistical tests. More explanations or literature support are needed to explain this part in this paper: why such a problem occurs; why research has certain defects, but the research content still has certain theoretical and practical significance; what additional supplements have been made in this study to fill the gaps in this aspect and so on. More detailed descriptions are needed in the article ( which may be added in the discussion section )
<Response>
On page 12, in Chapter 4, "Discussion," we added an explanation that the number of participants was small because of the limited duration of the study (lines 327-329).
Also, we have already added an explanation as to why the results of this study are important even though it failed to demonstrate the usefulness of MSE (lines 298 to 312).
Reviewer 2 Report
In this paper, the authors propose a new method to evaluate the asymmetry for lower limb movement patterns during sit-to-stand using elevation angle. In this study, only 8 subjects were included, four healthy and four rehabilitation patients. The experiment is well discussed, and the analysis is clear. However, there are some points that the authors need to provide and/or explain and some issues that need to be addressed.
The authors mentioned that the number of participants in their experiment was small, and they know it is a very significant limitation, especially when they are proposing an evaluation method! Did the author investigate the needed “sample size” for their experiment? It’s hard to draw a conclusion from this small number of subjects!
Have you considered the weight and height of the participants? To my knowledge, STS would be different for different weight groups! I would suggest including the participants' weight information in the paper, so the reader can make an informed decision about your experiment!
What is the gender of your participants? Have you included participants from the same gender? As you know, gait cycle is different between males and females and would at some point affect your results! Please include this information as gender is a very critical factor!
It's better to add a sketch that shows the elevation angles ?? and ?T of the thigh and lower leg and please edit figure 1 as it's not clear and it does not serve its purpose
For the results in figures 3 &4, I would prefer to see all the participants in one figure; For instance: the left thigh of all healthy participants vs unhealthy ones. If authors can add a figure comparing participants to help visualize the elevation changes in the patient group.
Author Response
■Have you considered the weight and height of the participants? To my knowledge, STS would be different for different weight groups! I would suggest including the participants' weight information in the paper, so the reader can make an informed decision about your experiment!
<Response>.
Added to the discussion a comparison of the previous study and this study with respect to the participants in the experiment. This study was conducted within a limited time frame. Only one medical institution was able to cooperate within that time frame, and the number of days of cooperation was only one day. The number of available rehabilitation patients that could be collected under these circumstances was small, resulting in a small number of participants in this study.
As the reviewer points out, it is difficult to draw conclusions from this study alone, but we did find the possibility that symmetry features may differ between healthy and rehabilitation patients in this experiment. We considered it worthy of further reporting.
■What is the gender of your participants? Have you included participants from the same gender? As you know, gait cycle is different between males and females and would at some point affect your results! Please include this information as gender is a very critical factor!
<Response>
We added Table.1 to Chapter 2, “Methods”, as a table summarizing participants' gender, weight, and height.
■It's better to add a sketch that shows the elevation angles ? and ? of the thigh and lower leg and please edit figure 1 as it's not clear and it does not serve its purpose.
<Response>
The four photos in Figure 1 were divided into (a)-(d) and a description was added to each. A new figure defining the thigh elevation angle and shank elevation angle was also added as Figure 3.
■For the results in figures 3 &4, I would prefer to see all the participants in one figure; For instance: the left thigh of all healthy participants vs unhealthy ones. If authors can add a figure comparing participants to help visualize the elevation changes in the patient group.
<Response>
While we understood the content of your review, we chose not to modify the figures.
The Figure 3-4 (already changed to Figure 4-5 in the revised version) that you pointed out is not shown to compare the lower limbs elevation angles between the healthy participant group and the patient group. Nor is it shown to compare lower limbs elevation angles within the same group. This is because the purpose of these figures is to clearly show the difference in elevation angles between the left and right thigh and the left and right lower leg within the same group.
Round 2
Reviewer 1 Report
This paper has been well revised.
Author Response
Thank you for approving the proposed revisions to the manuscript.
Reviewer 2 Report
Added to the discussion a comparison of the previous study and this study with respect to the participants in the experiment. This study was conducted within a limited time frame. Only one medical institution was able to cooperate within that time frame, and the number of days of cooperation was only one day. The number of available rehabilitation patients that could be collected under these circumstances was small, resulting in a small number of participants in this study. As the reviewer points out, it is difficult to draw conclusions from this study alone, but we did find the possibility that symmetry features may differ between healthy and rehabilitation patients in this experiment. We considered it worthy of further reporting.
- Unfortunately, I can not agree with you on this point. The authors have done an excellent job in preparing, performing and presenting their investigation. However, with this small number of participants, we can not say that your proposed symmetry features considered worthy. Your results show clearly that there is a 50% chance in Comparison Of R-L Symmetry By the R-L Vector Line between healthy and patient groups, as you say in your manuscript “In the healthy participants, four ?? values were negative, while in the rehabilitation patient group, two were positive and the remaining two were negative.”.
From your data I can draw a different conclusion that ?? values were negative in male participants and positive in female participants, regardless of being patient or healthy. My conclusion will be more accurate as 66.3% of female subjects were positive and 100% of male subjects were negative!
From that, I suggest including more subjects in the study to be able to draw a conclusion. Also, you can include female healthy subjects as this will not need any cooperation from any medical institution. But having female healthy group vs the female patient group that you already have would give a better conclusion for your proposed method.
We added Table.1 to Chapter 2, “Methods”, as a table summarizing participants' gender, weight, and height.
- Table 1 has critical flows. Your healthy group heights vs weights do not make any sense! How can you explain a normal healthy male with 177cm height can be only 33Kg in weight? Please make sure to check all the numbers in the table and correct the mean±SD! And if you are going to take my previous suggestion of including more subjects into consideration then make sure to have them healthy females with closer weight and age to patient group if possible!
Author Response
【Reviewer comment 1-1】
Your results show clearly that there is a 50% chance in Comparison Of R-L Symmetry By the R-L Vector Line between healthy and patient groups, as you say in your manuscript “In the healthy participants, four ?? values were negative, while in the rehabilitation patient group, two were positive and the remaining two were negative.”.
<Response 1-1>
There is a difference in the frequency of positive and negative ?? values between the healthy and patient groups. However, in this study, the positive and negative ?? values are unrelated to the frequency of symmetric and asymmetric STS movements.
Positive and negative ?? values indicates whether the dominant lower limbs used to achieve STS was the right or left side. "All four ?? values for the healthy group were negative" means that all four of the healthy group used the right lower limbs as their dominant lower limbs during STS movement. "Two of the ?? values in the patient group were positive and the other two were negative" means that two of the patient group used the right lower extremity as the dominant lower extremity during STS and another two used the left lower extremity as the dominant lower extremity during STS. In other words, the result is that the dominant lower limb direction was different between the healthy and patient groups, and the positive or negative ?? value is not an indicator for determining whether STS movements are symmetrical or asymmetrical. This explanation is provided on page 11, lines 284-286 and 289-292.
【Reviewer comment 1-2】
From your data I can draw a different conclusion that ?? values were negative in male participants and positive in female participants, regardless of being patient or healthy. My conclusion will be more accurate as 66.3% of female subjects were positive and 100% of male subjects were negative. From that, I suggest including more subjects in the study to be able to draw a conclusion.
<Response 1-2>
In light of your review, we have modified Tables 1 through 3 and Figures 4 through 7 to make it easier to see the relationship between subject characteristics and experimental results. We made the modification of representing each participant by a code (healthy subjects H-1 to H-4, patients P-1 to P-4) and relating each participant's code to all outcome data.
See Tables 1 and 3. From the two tables you can see: One of the five male participants had a positive ?? value and the other four had a negative ?? value. One of the three female participants had a positive ?? value and the other two had negative ?? values.
However, as discussed in response 1-1, positive and negative ?? values are not indicators of symmetry or asymmetry. Therefore, we do not think it is necessary to discuss whether the factor that determines the positive or negative ?? value is the healthy or patient group, male or female.
【Rvewer comment 2】
Table 1 has critical flows. Your healthy group heights vs weights do not make any sense! How can you explain a
normal healthy male with 177cm height can be only 33Kg in weight? Please make sure to check all the numbers in the table and correct the mean±SD!
<Response 2>
As you pointed out, there was an error in the entries in Table 1. We had entered the opposite weight data for healthy subjects and for patients. Therefore, we have corrected the weight data for both groups correctly. In addition, we verified that the other data were entered correctly.
