New Training Tasks for Stepwise Loading in Isometric Bodyweight Squat with Active Posture Control

Round 1

Reviewer 1 Report

This is a reasonably well written paper that presents a novel training approach. Unfortunately, the study design did not involve any training intervention and appears to not build upon the research group’s previous findings. Please provide more information concerning the effectiveness of performing the “new training tasks” on muscle performance and function. Please see my other comments below.

 

Line 44: Please provide more information about how the load was increased and where this load was applied? As an example, load on knees.

Line 50: Why is a training programmed based on isometric squats needed? What are the benefits and to what population/s?

Lines 60-67: This reads more like the rationale for the study and should be placed in the Introduction and not Methods section.

Lines 115-118: For the training intervention this information should be included in the Methods section.

Line 149: But how about dynamic squats when it comes to improving function for the elderly or people with mobility issues?

Line 159; What is meant by “appropriate training strength”? Please elaborate.

Lines 170-171: You cannot say that “the new training tasks of isometric bodyweight squat can be useful” because you did not conduct a training intervention.

Author Response

Answer to the Reviewer #1

Thank you very much for your valuable comments and suggestions.

 

• With regard to the reviewer's comment on line 44.

In this study (and our previous study Ref#15), we measured the muscle activities of the right vastus medialis (VM), semitendinosus (ST), lateral head of the gastrocnemius (GL), and tibialis anterior (TA). As these muscles are the main component of lower limb kinetics (and kinematics), with hip, knee, and ankle joints, the activities reflect the training loads for specific muscles. We added sentences as follows.

In the study, we focused on the muscle activities of the vastus medialis (VM), semitendinosus (ST), lateral head of the gastrocnemius (GL), and tibialis anterior (TA). Because these are the main components of lower limb kinetics and kinematics, the activities reflect the training loads for each muscle.  

 

• With regard to the reviewer's comment on line 50.

We believe that isometric bodyweight squat is ideal for the elderly with a risk of frailty. Compared with dynamic training, isometric training provides muscle strengthening without joint motion, indicating gentle joint loading. Further, a bodyweight squat can be performed in a limited space without any equipment. It can be performed at home without supervision. Therefore, we think that program-based training could be an ideal training approach for the elderly.

We added sentences as follows.

Isometric exercises provide moderate muscle strengthening without joint motion [13,14], indicating gentle joint loading.

 

• With regard to the reviewer's comment on lines 60-67.

We agree that these sentences should be placed in the Introduction section. Therefore, we moved this part to the last part of the Introduction section.

 

• With regard to the reviewer's comment on lines 115-118.

We agree that these sentences should be placed in the Method section. Therefore, we moved this part to the Method section (2.1. Subjects).

 

• With regard to the reviewer's comment on line 149.

Dynamic squats have many advantages in improving functions, especially for a healthy population. For the elderly, it would be safe and effective if carefully supervised. On the other hand, several studies warned that it could injure the elderly to perform high flexion activities (e.g., Han SY et al. The Relation of Three-dimensional Knee Kinematics between Walking and Squatting for Healthy Young and Elderly Adults. J Phys Ther Sci 2014,26:465-7). From these kinematic aspects, we think that the isometric exercise would be suitable for the elderly with a risk of frail.  

 

• With regard to the reviewer's comment on line 159.

In this study, we created stepwise loading tasks and confirmed the feasibility with healthy participants. However, we are just at a starting point, and when we apply the tasks for the elderly, appropriate training intensity should be different on the individual conditions.

We changed the word “strength” to “intensity.”       

 

• With regard to the reviewer's comment on lines 170-171.

We understood that we could not say “the new training tasks of isometric bodyweight squat can be useful” because we did not conduct a training intervention. However, as a context we wrote above, we would like to mention a possibility of these tasks for the elderly in various clinical conditions, where dynamic exercise is overload. Therefore, we altered sentences as follows.

The new training tasks of isometric bodyweight squat could be useful for the elderly in various clinical situations wherein closed kinetic chain exercise should be used upon careful physical examination for fatigue or pain in each muscle group.

Reviewer 2 Report

Thanks to the editor for allowing me to review the work.
The work is correct and well set up.
There are two minor revisions to be made. Within the materials and methods insert a population section and then describe it in the results.
I also ask you to include these quotes within the introduction.
Flocco, P., Galeoto, G. Effect of blood flow restriction training on physiological outcomes in healthy athletes: A systematic review and meta-analysis Muscles, Ligaments and Tendons Journal, 2021, 11 (1), pp. 101–117
Miccio, S., Berardi, A., Tofani, M., Galeoto, G. Conservative rehabilitation treatments of iliotibial band syndrome: A systematic review Muscles, Ligaments and Tendons Journal, 2021, 11 (1), pp. 29–40

Author Response

Answer to the Reviewer #2

Thank you very much for your valuable comments and suggestions.

 

• With regard to the reviewer's comment on the materials and methods.

We added a new section as follows.

2.1. Subjects

   Ten healthy men with no history of knee injury, knee pain, or surgery participated in this study. All had squat experience. The content of the experiment was sufficiently explained to the subjects, and only those who voluntarily agreed to participate in the experiment were enrolled. All subjects provided informed consent for the study procedures. Participation was voluntary and in agreement. The study was conducted in accordance with the principles of the Declaration of Helsinki and the laws and regulations of Japan. This study was approved by the ethics committee of Nara Medical University (No. 1969). No subjects had difficulty to hold the squat position for 5 seconds.

 

We also modified sentences in the Results section as follows.

The ten participants performed this study.

 

• With regard to the reviewer's comment on new references as you suggested.

We added a new references as follows.

(Ref.#2) Flocco, P.; Galeoto, G. Effect of blood flow restriction training on physiological outcomes in healthy athletes: A systematic review and meta-analysis Muscles, Ligaments Tendons J., 2021, 11, 101–117.

(Ref.#4) Miccio, S.; Berardi, A.; Tofani, M.; Galeoto, G. Conservative rehabilitation treatments of iliotibial band syndrome: A systematic review Muscles Ligaments Tendons J., 2021, 11, 29–40.

Reviewer 3 Report

This is a well-written pilot study with interesting and valuable results that can contribute to knowledge in the field and aid further research with a higher number of subjects as a sample.

Please consider the following observations:

Line 20 – please change to electromyogram (EMG).

Line 47 – please change to pilot study.

Line 51 – The methods section must include the ethical approval, reference to the approval document, declare if the subjects signed written informed consent or not, according to the Declaration of Helsinki, the inclusion and exclusion criteria and so on.

Line 91 – please change affected to induced.

Line 96 – please change was to were.

Line 98 – please change to differences were found.

Line 103 – Figure 1: The dispersion bars for each column are not visible, especially in the blue ones. Please change to black.

Line 123 – Figure 2: a block diagram similar to a flowchart would be helpful to understand the sequence.

Line 128 – Figure 3: The paper would be improved if a real model performing the exercises was included in this figure rather than the schematics.

Line 132 – The discussion should include the limitations of this pilot study. For example, sample size, heterogeneity, gender, training background and so on.

Lines 169 t0 171 – this sentence should be restructured, for example: The new training tasks... can be useful for the elderly in various... upon...

Author Response

Answer to the Reviewer #3

Thank you very much for your valuable comments and suggestions.

 

• With regard to the reviewer's comment on line 20.     We have changed to “electromygram (ECG).”
• With regard to the reviewer's comment on line 47.
  We have changed to “pilot study.”
• With regard to the reviewer's comment on line 51.                      We added sentences as follows in a new section “2.1. Subjects” in the Methods.

The study was conducted in accordance with the principles of the Declaration of Helsinki and the laws and regulations of Japan. All subjects provided informed consent for the study procedures. Participation was voluntary and in agreement. This study was approved by the ethics committee of Nara Medical University (No. 1969).

• With regard to the reviewer's comment on line 51.      We changed “affected “ to “induced.”
• With regard to the reviewer's comment on line 96.      We changed “was “ to “were.”
• With regard to the reviewer's comment on line 98.      We changed “significant differences were found.”
• With regard to the reviewer's comment on line 103 (Figure 1).

We changed the bars to black.

• With regard to the reviewer's comment on line 123 (Figure 2).

We changed figures to a flowchart style.

• With regard to the reviewer's comment on line 128 (Figure 3).

We changed figures with real models.

• With regard to the reviewer's comment on line 132.

We added sentences as follows. This pilot study has some limitations, including sample size, gender, and training background of participants.

• With regard to the reviewer's comment on lines 169-171.

We restructured the sentences as follows under your suggestion.

The new training tasks of isometric bodyweight squat could (changed based on Reviewer #1 comment) be useful for the elderly in various clinical situations wherein closed kinetic chain exercise should be used upon careful physical examination for fatigue or pain in each muscle group.

 

Round 2

Reviewer 1 Report

The manuscript has been improved.

Author Response

Thank you very much for the comments.

Reviewer 3 Report

This reviewer appreciates the authors effort to improve the manuscript and considers that all the observations were answered satisfactorily.
Best wishes with your publication

Author Response

Thank you very much for the comments.