The Effect of Muscles Fatigue on the Knee’s Kinetics and Kinematics Characteristics

Round 1

Reviewer 1 Report

Dear authors,

 

Thank you very much for the effort you put into your research. Your research is very valuable in terms of its subject and scope, I think that after the corrections I will mention below, your research may be suitable for publication in the sustainability journal.

 

Introduction

 

Please delete the general information about the badminton branch between Line35-38. These are already known facts and I don't think they are necessary.

 

Methods

 

-Only 12 subjects were used in your study, is this figure sufficient for power analysis? If it is sufficient, add your power analysis results; if not, indicate this situation as a limitation.

-The procedure you use for fatigue looks like an old procedure. How many repetitions did the subjects do in 3 minutes on average for fatigue? Isokinetic dynamometers can give a fatigue index after 15 repetitions, why did you choose a 3-minute procedure? Also, if possible and if you have data, when did the subjects reach maximum torque in the 3-minute procedure? what was the minimum torque? What were the Fatigue indexes? I would appreciate it if you could give these results as a table.

-In addition, the risk of disability in the extension and flexion phases can be monitored with the H/Q ratio. What were the post-fatigue H/Q ratios that emerged in your research? If you have data, it would be nice if you could provide it.

-also, as you know, con/con contraction is against the main movement structure of the knee in terms of function. I would appreciate it if you add an explanation to the discussion section about why you don't have concentric/eccentric contractions since you measured fatigue with con/con contraction in your research.

 

If you add the reasons I wrote above, it will increase the quality of your research. However, if you do not have these data, your work can be published in its current form. try to provide all the data you can add, if not, reload in as many edits as you can.

 

Yours sincerely

Author Response

Response to Reviewer 1 Comments

Point 1:

Thank you very much for the effort you put into your research. Your research is very valuable in terms of its subject and scope, I think that after the corrections I will mention below, your research may be suitable for publication in the sustainability journal.

Response：We would like to thank the reviewer 1 for the careful analysis he/she has done of our manuscript and the positive evaluation of this paper. His/her comments contributed to a significant improvement to our manuscript. According to your suggestion, we have revised the manuscript according.

 

Point 2:

Introduction

Please delete the general information about the badminton branch between Line35-38. These are already known facts and I don't think they are necessary.

Response: Lines 35-38 mentioned badminton is so popular in the worldwide, so the relative study like this paper is important to prevent injury for players when playing badminton. We think some sentences about the popularity of badminton is useful to strength the necessity of this study, so we keep these sentences.

 

Point 3:

Only 12 subjects were used in your study, is this figure sufficient for power analysis? If it is sufficient, add your power analysis results; if not, indicate this situation as a limitation.

Response: Thank you very much for your advice. We have added the calculation method of sample size, please refer to line 89.

 

Point 4:

The procedure you use for fatigue looks like an old procedure. How many repetitions did the subjects do in 3 minutes on average for fatigue? Isokinetic dynamometers can give a fatigue index after 15 repetitions, why did you choose a 3-minute procedure? Also, if possible and if you have data, when did the subjects reach maximum torque in the 3-minute procedure? what was the minimum torque? What were the Fatigue indexes? I would appreciate it if you could give these results as a table.

Response: As you said, the procedure we use for fatigue is referred to previous studies. We did not count the flexion and extension movement times in three minutes. The isokinetic dynamometer was only used to make athletes tired and calculate the average maximum muscle force value in last three minutes. Three minutes is one group. When the average maximum muscle strength of the knee joint muscles decreased to 50% of the maximum muscle strength in three consecutive groups, we considered the subject fatigued. Please see lines 157-162.

 

Point 5:

In addition, the risk of disability in the extension and flexion phases can be monitored with the H/Q ratio. What were the post-fatigue H/Q ratios that emerged in your research? If you have data, it would be nice if you could provide it.

Response: The use of isokinetic dynamometers was mainly used to quantify the fatigue state of subjects. What we mainly want to discuss is how the kinetic and kinematic indicators of knee joint would change after fatigue. H/Q ratio is not the point we concerned, so we didn’t analyze and discuss it.

 

Point 6:

Also, as you know, con/con contraction is against the main movement structure of the knee in terms of function. I would appreciate it if you add an explanation to the discussion section about why you don't have concentric/eccentric contractions since you measured fatigue with con/con contraction in your research.?

Response: Thank you for the suggestion. We have added some sentences about contraction and centrifugal contraction in the discussion section. Please see lines 238-242.

 

 

 

Author Response File: Author Response.docx

Reviewer 2 Report

The study discusses about the effect of muscles fatigue on the anterior cruciate ligament injury risk of amateur badminton players at the moment of forehand lunge touching the ground. The manuscript is of interest for sport biomechanics experts. However, some information should be added to the manuscript before it can be accepted for publication. My comments are as follows.

 1.      Authors do not show quantitatively the ACL injury risk. Therefore, “the effect of muscles fatigue on the knee’s kinetics and kinematics” would be more suitable for the title of the manuscript.   

2.      Could you provide a figure shows the directions and coordinate systems of the knee.

3.      What are the hatched areas shown in Figure 4?

Author Response

Response to Reviewer 2 Comments

Point：1

The study discusses about the effect of muscles fatigue on the anterior cruciate ligament injury risk of amateur badminton players at the moment of forehand lunge touching the ground. The manuscript is of interest for sport biomechanics experts. However, some information should be added to the manuscript before it can be accepted for publication. My comments are as follows.

Response: We would like to thank the reviewer 1 for the careful analysis he/she has done of our manuscript and the positive evaluation of this paper. His/her comments contributed to a significant improvement to our manuscript. According to your suggestion, we have revised the manuscript according.

 

Point：2

Authors do not show quantitatively the ACL injury risk. Therefore, "the effect of muscles fatigue on the knee's kinetics and kinematics" would be more suitable for the title of the manuscript.

Response: We absolutely agree with your opinion, the change have been made as you suggested.

 

Point：3

Could you provide a figure shows the directions and coordinate systems of the knee.

Response: we have added figure 2 to explain the directions and coordinate systems of the knee. Please see lines 128.

 

Point：4

What are the hatched areas shown in Figure 4?

Response: The hatched areas in Figure 4 is the standard deviation.

 

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Congrats. Your manuscript is ready to publish.

Best.