Effects of Progressive Elastic Resistance on Kinetic Chain Exercises Performed on Different Bases of Support in Healthy Adults: A Statistical Parametric Mapping Approach

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

I have received the original research article entitled “Effects of Progressive Elastic Resistance on Kinetic Chain Exercises Performed on Different Bases of Support: A Statistical Parametric Mapping Approach,” which is under consideration for publication in Medical Journal Biomechanics. In my opinion, the article is generally well-prepared and presents scientific value. I would like to suggest a major corrections and clarifications, as outlined below:

1. The title could be clarified to specify that the study was conducted in “healthy adults” to avoid giving the impression that the results are directly applicable to rehabilitation patients.

2. The sample size (36 participants) may be insufficient to detect subtle exercise × resistance interaction effects. It would be helpful to include a statistical power analysis.

3. The manuscript does not provide a sample size calculation.

4. The term “convenience sampling” should be clarified — how were participants specifically recruited?

5. Exclusion criteria are not explicitly listed and should be provided.

6. A limitation is the absence of a comparison or control group, which could strengthen the study.

7. The description of the TheraBand® resistance could be more precise — for example, specifying the resistance in Newtons or as a percentage of body mass for each band color. Although this is mentioned in the discussion, it would be clearer in the Methods section.

8. Randomization of exercise order is not described. This could affect results due to fatigue or learning effects.

9. Effect sizes (e.g., η²) are not reported; currently, only p-values are provided.

10. Clinical interpretation of the results is limited; it would be useful to include more direct clinical relevance in the Results section rather than postponing it entirely to the Discussion.

11. The Discussion occasionally repeats the Results section; it could be condensed to improve clarity and flow.

Overall, the manuscript provides valuable insights into scapular kinematics during kinetic chain exercises, but addressing the points above would strengthen its clarity and scientific rigor.

Author Response

Response 1: Thank you for pointing this out. I/We agree with this comment. Therefore, I/we have….[1 - The title was updated to explicitly state “healthy adults”. This wording reflects the reviewer’s recommendation and ensures clarity regarding the characteristics of the study population. No additional modifications were made to the title beyond this inclusion. – Line 1.]
“[“Effects of Progressive Elastic Resistance on Kinetic Chain Exercises Performed on Different Bases of Support in Healthy Adults: A Statistical Parametric Mapping Approach.”]”

….[2 - An a priori sample size calculation was added using G*Power. Based on the selected statistical model, the analysis indicated a power of 0.92, confirming that the sample size was adequate for detecting the expected effects. – Lines 109-115.]
“[An a priori sample size calculation…]”

…[3 - Recruitment procedures were clarified in the Methods. Participants were recruited through “convenience sampling from the academic community”, ensuring transparency regarding sample origin. – line 97.]
“[Participants were recruited through convenience sampling from the academic community]”

….[4 - All exclusion criteria were rewritten and clearly listed. The exclusion criteria have been rewritten and are now clearly stated as a dedicated list to enhance transparency and reproducibility of participant selection. – Lines 99–101.]
“[Individuals were excluded if they reported any of the following: (1) shoulder or neck issues for the past 6 months, (2) a history of shoulder fractures, or (3) previous shoulder surgeries]”.

….[5 - This limitation has been explicitly acknowledged in the revised manuscript. We clarified that although no external control group was included, the comparison between exercises and resistance conditions serves as an internal control, and this has been discussed as a methodological limitation. – Lines 357–362.]
“[Second, the cross-sectional design does not allow inferences about causal relationships or long-term adaptations. Third,…]”.

….[6 - A new table (Table 2) was added including force values at 100% elongation and corresponding percentages of body mass for each TheraBand® colour used. Additional explanation regarding resistance determination was incorporated into the Methods section. – Lines 184–185.]
“[Table 2]”.

….[7 - The Methods section now explicitly states that the order of the resistance conditions was randomized to minimize potential fatigue or learning effects. – Lines 165–166.]
“[All three conditions were performed in a randomized order.]”.

….[8 - We have added partial eta-squared (η²p) as the effect size measure for all SPM analyses, following standard reporting guidelines. – Lines 208–275.]
“[Results section]”.

….[9 - We expanded the Discussion to more explicitly articulate the clinical implications of the observed scapular adaptations across exercise types and resistance conditions, ensuring stronger translational relevance. – Lines 276–362.]
“[Discussion section]”.

….[10 e 11 - The Discussion was thoroughly reorganized. Redundant descriptions were removed, and the narrative was refined to improve clarity, analytical depth, and flow. – Lines 276–362.]
“[Entire Discussion section]”.

Reviewer 2 Report

Comments and Suggestions for Authors

First of all, I would like to thank you for invited to read the document.

The authors have done an excellent job. Each of the comments shared are intended to improve the study.

The comments can be found in the PDF document.

Also, some of the comments on some of the points that need to be reworded in the paper are shared below:

Abstract

It´s suggest reviewing the following comments in the abstract:

- In the methodology section, it is necessary to specify the type of research (experimental, cross-sectional, longitudinal, etc.).

- Specify or mention the main characteristics of the participants.

- Expand on the conclusions of the study.

Introduction

The introduction needs to be strengthened, especially when referring to the assessment of progressive elastic resistance in adults. In addition, the concepts (elastic resistance, kinetic chain) need to be defined more precisely.

Furthermore, the introduction does not mention the different bases of support in sufficient detail.

Revision and adjustment are suggested.

Line 36-37. To begin providing context on the problem to be solved, we suggest briefly discussing the effects reported in these studies and how they were investigated.

Line 43-44. There are studies that have reported injury prevention from this type of exercise. It is suggested that these be reported.

Line 53-54. Which ones and what have all these studies reported?

Material and method

In the section on materials and methods, some clarifications are necessary

- Detail the study methodology in terms of the design used
- It is suggested that an image be added to illustrate movement 1 (OHS) and movement 2 (KP)
- The procedure is quite confusing. It is suggested that a diagram be designed to illustrate the evaluation and that a step-by-step description be provided.
- The type of warm-up and the load to be moved are not reported.
- It´s suggested that other criteria taken into account be reviewed.
- Although the sampling was done for convenience, was any power test performed to define the sample size?

Results

In the results section, some clarifications are necessary

- The statistical values with p-values in the methods section with the participants are not understood.

- Other tables are needed to show the data at a descriptive and inferential level for better understanding. Refer to the data that showed statistically significant differences.

- The results section shows several results that were different, but they are not reported in any table to aid understanding.

- It is mentioned to see tables 2 and 3, however, only one table is reported in the study.

- Figures 2d, 1a, and 3c are confusing; it would be necessary to add some explanation before them.

- It is suggested to review the quality of the images so that the results can be seen better.

Discussion

If only one type of band was used, how were the results discussed with other studies that used other band colors?

Furthermore, neither the study itself nor other studies reported the weight shifted in the movement assessment. 

The number of repetitions may affect or hinder the assessment. These results were compared with other protocols from previous studies.

Finally, it is unclear whether the studies discussed were related in any way to the participants in the present study. 

It´s suggested that the discussion be revised and restructured to provide more support for the main findings of the study.

Line 275-282. This section appears to be an extension of the results. It is suggested that it be reviewed and compared with the available scientific evidence.

Line 283-287. It´s suggested that the limitations and perspectives of the study be reviewed in depth, especially in relation to sample size, study design, population characteristics, type of exercise, etc.

Conclusions

It´s suggested that the conclusions should state that these findings were made in a specific population.

References

It´s recommended to review the references used, as a large part of them are from studies conducted in the last 5 years.

 

Finally, the comments made are intended to improve the quality of your work

Comments for author File: Comments.pdf

Author Response

Comments 1: [Abstract
It´s suggest reviewing the following comments in the abstract:
1 - In the methodology section, it is necessary to specify the type of research (experimental, cross-sectional, longitudinal, etc.).
2 - Specify or mention the main characteristics of the participants.
3 - Expand on the conclusions of the study.]

Response 1: Thank you for pointing this out. We agree with this comment. Therefore, we have…[1 - We appreciate this suggestion. The abstract now clearly specifies the study design: “This is a cross-sectional study…”. Lines 15–17.]
“[This cross-sectional study analyzed three-dimensional shoulder kinematics in 36 healthy adult male participants during the overhead squat and kneeling position exercises.]”
…[2 - The abstract was updated to include the main participant characteristics: “36 healthy adult male participants.”. Lines 16–17.]
“[…36 healthy adult male participants during the overhead squat and kneeling position exercises.]”
…[3 - The conclusions in the abstract were expanded to better summarize the key differences observed between exercise types and resistance conditions.”. Lines 29–31.]
The resistance and exercises demonstrated different kinematic strategies that helped maintain scapular stability during movement.]”
Comments 2: [Introduction
1 - The introduction needs to be strengthened, especially when referring to the assessment of progressive elastic resistance in adults. In addition, the concepts (elastic resistance, kinetic chain) need to be defined more precisely.
2 - Furthermore, the introduction does not mention the different bases of support in sufficient detail.
3 - Revision and adjustment are suggested.
4 - Line 36-37. To begin providing context on the problem to be solved, we suggest briefly discussing the effects reported in these studies and how they were investigated.
5 - Line 43-44. There are studies that have reported injury prevention from this type of exercise. It is suggested that these be reported.
6 - Line 53-54. Which ones and what have all these studies reported?]
Response 2: Thank you for pointing this out. We agree with this comment. Therefore, we have. [1 - The Introduction was strengthened by adding clearer and more comprehensive definitions of elastic resistance and kinetic chain, providing a stronger conceptual foundation for the study. Elastic resistance lines 42-45 and Kinetic Chain Lines 49-54.]
“[Elastic resistance, commonly delivered through elastic bands, rubber bands, and tubing, provides a mechanical load that increases linearly with elongation. It is considered an effective and accessible tool for rehabilitation, showing activation levels comparable to isoinertial resistance [6], free weights, or training machines [7].] and “[In recent years, growing attention has been directed toward exercises that integrate the kinetic chain (KC) concept [10-12], which emphasizes the coordinated transfer of force and motion among the lower limb, trunk, and shoulder complex. The KC encompasses the sequential activation of body segments during daily and sports-specific tasks[10,13], progressing through the hip and trunk, and ultimately influencing upper-limb movement [11,14].]”

…[2 - A definition of base of support (BoS) and its biomechanical relevance was added to improve conceptual clarity.”. Lines 68–75]
[Body positioning, particularly the base of support (BoS), may also influence scapular control. The BoS refers to the area between a body segment or an external support surface in contact with the ground, which determines postural stability [22]. A wider BoS enhances stability, whereas a narrower BoS increases postural demand and may consequently modify KC involvement and neuromuscular activation patterns [23]. Previous studies comparing exercises with different BoS configurations have demonstrated changes in kinematics and muscle recruitment, suggesting that BoS plays a relevant role in how elastic resistance affects scapular motion [24,25].]”

…[3 - The Introduction was reorganized and refined to improve readability, coherence, and alignment with the study aims.”. Lines 36–92]
“[Several studies have examined the effects of exercise on scapular kinematics in both healthy individuals and those with shoulder disorders [1,2], supporting the use of scapular-focused exercise therapy...]”

…[4 - We added a concise summary of the key findings from previously cited studies, clarifying the context and relevance to the current research.”. Lines 37–38.]
“[…supporting the use of scapular-focused exercise therapy.]”

…[5 - We added studies demonstrating the preventive effects of kinetic chain–based exercises.”. Lines 47.]
“[…for preventing injuries such as scapular dyskinesis and subacromial pain syndrome.]”

…[6 - We expanded this section by explicitly describing which studies were referenced and the specific findings reported.”. Lines 61–67.]
“[Previous studies have reported changes in scapular upward rotation, posterior tilt, and internal/external rotation depending on resistance direction and trunk posture [18-20], providing limited insight into how resistance direction and body positioning influence scapular motion within the KC [11,21]. Existing evidence also shows that integrating elastic resistance into the KC alters load transmission pathways from the lower limbs and trunk to the upper limb [11,21], which subsequently modifies scapular control strategies [10,13].

Comments 3: [Material and method
In the section on materials and methods, some clarifications are necessary
1 - Detail the study methodology in terms of the design used
2 - It is suggested that an image be added to illustrate movement 1 (OHS) and movement 2 (KP)
3 - The procedure is quite confusing. It is suggested that a diagram be designed to illustrate the evaluation and that a step-by-step description be provided.
4 - The type of warm-up and the load to be moved are not reported.
5 - It´s suggested that other criteria taken into account be reviewed.
6 - Although the sampling was done for convenience, was any power test performed to define the sample size?
]
Response 2: Thank you for pointing this out. We agree with this comment. Therefore, we have. [1 - The study design is now clearly identified as cross-sectional in the Methods section. – Line 96.]
“[...cross-sectional study]”

[2 - Images illustrating the initial and final positions of the OHS and KP exercises were added. – Lines 184-185.]
[Table 2]”

[3 - A procedural flow diagram and clearer step-by-step description were added to improve methodological transparency. – Lines 135–136.]
[Figure 1]”

[4 - The Methods section now includes a description of the warm-up protocol and details regarding the elastic resistance load. – Lines 142.]
[The warm-up consisted of 5 repetitions of OHS or KP.]”

[5 - We clarified additional protocol criteria, including functional screening tests and required movement patterns. – Lines 101-102.]
[To ensure the absence of functional alterations in the lower limbs, KC, all participants completed…]”

[6 - Yes. A full a priori sample size calculation using G*Power was added to justify the sample size. – Lines 108-115.]
[An a priori sample size calculation was …]”

Comments 4: [Results
In the results section, some clarifications are necessary
1 - The statistical values with p-values in the methods section with the participants are not understood.
2 - Other tables are needed to show the data at a descriptive and inferential level for better understanding. Refer to the data that showed statistically significant differences.
3 - The results section shows several results that were different, but they are not reported in any table to aid understanding.
4 - It is mentioned to see tables 2 and 3, however, only one table is reported in the study.
5 - Figures 2d, 1a, and 3c are confusing; it would be necessary to add some explanation before them.
6 - It is suggested to review the quality of the images so that the results can be seen better.]
Response 2: Thank you for pointing this out. We agree with this comment. Therefore, we have. [1 - Independent and dependent variables were clearly defined to improve clarity in the statistical methods – Lines 181–184.]
“[The independent variables included exercise…]”

[2 and 4 - We exclude the tables and include the angular range together the significant percentage of the circle.]
“[...main effect of exercise from 25.7% to 32.8% of the cycle (31–39˚, p = 0.04, η²ₚ = 0.57),…]”

[3 - We clarified that SPM is a continuous time-series analysis, for which pointwise tabulation is not appropriate. Instead, suprathreshold regions and effect statistics are reported comprehensively in figures and text.]
“[Results]”

[5 - Figures were revised, relabelled, and reorganized to enhance clarity.]
“[Figures 3–5]”

[6 - All images have been exported at higher resolution and improved for clarity.]
“[Figures 3–5]”
Comments 5: [Discussion
1 - If only one type of band was used, how were the results discussed with other studies that used other band colors?
2 - Furthermore, neither the study itself nor other studies reported the weight shifted in the movement assessment. 
3 - The number of repetitions may affect or hinder the assessment. These results were compared with other protocols from previous studies.
4 - Finally, it is unclear whether the studies discussed were related in any way to the participants in the present study. 
5 - It´s suggested that the discussion be revised and restructured to provide more support for the main findings of the study.
6 - Line 275-282. This section appears to be an extension of the results. It is suggested that it be reviewed and compared with the available scientific evidence.
7 - Line 283-287. It´s suggested that the limitations and perspectives of the study be reviewed in depth, especially in relation to sample size, study design, population characteristics, type of exercise, etc.]
Response 2: Thank you for pointing this out. We agree with this comment. Therefore, we have. [1 - We clarified that previous studies with the same sample demonstrated no significant kinematic differences across TheraBand® colours. This rationale was added to justify band selection. – Lines 178–181.]
“[Elastic resistance was applied using color-coded bands, with the specific band assigned to each exercise shown in Table 2…]”

[2 - We clarified that weight-shifting is inherent to kinetic chain–based exercises and provided supporting references. – Lines 50-51 and 64-67.]
“[…which emphasizes the coordinated transfer of force and motion among the lower limb, trunk, and shoulder complex.] and [Existing evidence also shows that integrating elastic resistance into the…]”

[3 - We noted that our protocol aligns with established methodologies using five repetitions, ensuring consistency with prior literature. – Lines 179–181.]
“[Our previous work demonstrated no significant differences between blue and black bands during OHS [24], nor between red and black bands during KP [25].]”

[4 - We clarified that earlier studies referenced in the manuscript were conducted with the same participant sample. – Lines 181–182.]
“[Therefore, these color combinations were adopted to maintain consistency across resistance conditions.]”

[5 - The Discussion was reorganized to strengthen interpretation, coherence, and connection to the main findings.]
“[Entire Dicussion]”

[6 - Redundancies were removed and the section was rewritten to focus on interpretation supported by prior evidence.]
“[corrected]”

[7 - The Limitations section was expanded to more thoroughly address study design constraints, sample characteristics, and generalizability. - Lines 357–362.]
“[Second, the cross-sectional design does not allow inferences about causal relationships or long-term adaptations. Third,…]”
Comments 6: [Conclusions
It´s suggested that the conclusions should state that these findings were made in a specific population.]
Response 2: Thank you for pointing this out. We agree with this comment. Therefore, we have. [1 - We clarified that previous studies with the same sample demonstrated no significant kinematic differences across TheraBand® colours. This rationale was added to justify band selection. – Lines 364–366.]
“[The exercises revealed that they contribute to scapulohumeral rhythm and stabilization during the overhead moment, highlighting their effectiveness as kinetic chain–integrated exercises]”
Comments 7: [References
It´s recommended to review the references used, as a large part of them are from studies conducted in the last 5 years.]
Response 2: Thank you for pointing this out. We desagree with this comment. Therefore, we have. [keeped the references]”

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Thank you for the detailed and comprehensive revisions provided in response to my comments. I have carefully reviewed the updated manuscript as well as the point-by-point responses. The authors have addressed all previously raised concerns thoroughly and adequately.

Overall, the manuscript has been significantly improved in clarity, methodological transparency, and scientific rigor. The authors have satisfactorily addressed all major and minor issues.

I recommend the manuscript for publication in its current form.

Reviewer 2 Report

Comments and Suggestions for Authors

First of all, I would like to thank you for invited to read the document.

The authors have done an excellent job. The authors have been able to resolve all of my concerns and observations.

He considered that substantial modifications had been made to the document, which improved its methodological quality. 

I believe the document meets the quality standards for publication in the journal.