Upper-Limb and Low-Back Load Analysis in Workers Performing an Actual Industrial Use-Case with and without a Dual-Arm Collaborative Robot

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

1. Please rewrite the Introduction section. Please concise the background introduction “In the industry 4.0 scenario, Human–Robot Collaboration plays a key role in factories to 13 reduce cost, increase production and help aged and/or sick workers maintain their job. However, nowadays there is still a lack of evidence of their benefical effect that needs to be further investigated. Common specific biomechanical risk assessment tools listed in the ISO 11228 series can be hardly applied in industry 4.0, since their mathematical models cannot predict how robotic devices may interact with the human body. The use of wearable technologies and software for biomechanical risk assessment could help us have a more reliable idea on the effectiveness of collaborative robot (coBots) in reducing biomechanical load for workers.”. In the remainder of the introduction from "Eleven participants" to the end, the reviewer would like to see more statistics (obtained from experiments, e.g. 50.2% to 3.0%, 68.4% to 7.4%) to bolster the statement of " using the cobot in this particular industrial scenario, would reduce the biomechanical risk for workers.".

2. At the end of the Introduction section, the authors should introduce the research logic and structure of the rest sections of this paper, facilitating the audiences to have a better understanding of it.

3. For Table 1, Table 2, and Table 3, the data are hard to read and compare. The authors shall consider demonstrate these data in bar chart format to improve readability and comparison among the different groups listed in the first and second columns of each table.

4. In the Conclusion section, clearly state the contributions of this paper and outline future research direction if appliable.

5. For reference section, there exist errors. The reference between lines 532 and 533 was numbered as "A". Citation No. 64 and 65 should be merged and corrected to "Feola E, Refai MI, Costanzi D, Sartori M, Calanca A. A Neuromechanical Model-Based Strategy to Estimate the Operator’s Payload in Industrial Lifting Tasks. IEEE Transactions on Neural Systems and Rehabilitation Engineering. 2023 Nov 20;31:4644-52." Last, ensure all references follow a uniform standard format. 

Comments on the Quality of English Language

There exist some minor issues. For example, "(Varrecchia et al., , 2023" in line 82, "Silvetti, 2021, 2020, 2019, 2016, ; " in line 106. In addition, the sentence between lines 153 and 156 is hard to understand. Please improve clarity of the sentence.

Author Response

Dear Rewiever you can find attached our replies.

Best

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The study compares the performance of a limited number of relatively young participants with near-average BMI in a task that requires mechanical effort of the limbs and may overload the lower back. The task is performed both without support equipment and with it (collaborative robot or CoBot).

INTRODUCTION
The introduction focuses extensively on CoBots themselves, and mentions the method used in the kinematic study (3DSSPP), but largely overlooks the existing literature on the biomechanics of lower-back and limb injuries. While the work is clearly explained and well-designed, it lacks significant innovation and does not lead to particularly interesting conclusions.

MATERIALS AND METHODS
The procedure used is well described in this section, making the paper easy to read. However, a limitation noted is that only kinematic reconstructions from images are made using software, which can have a higher error rate compared to direct measurements with devices placed on the experimental subjects.

RESULTS
The results are clearly explained but are too predictable. The statistical analysis is correct but limited to obtaining p-values, without discussing the underlying distribution of the data. Consequently, there is uncertainty about whether the p-value analysis is entirely adequate.

DISCUSSION
The discussion is primarily a comparative summary of results, with some references to studies using different methodologies, though more comparisons are needed. At the end of the discussion, a pertinent possible limitation or criticism of the methodology is added, which is intellectually honest. However, there is once again a lack of reference to injury biomechanics.

CONCLUSION
The conclusion seems somewhat hasty, as neither the results, methods, nor discussion have explained how the value of certain measured parameters affects biomechanical risk. Although the conclusions seem plausible, the relationship between the parameters and the risks of injury should be better explained in the body of the article.

Author Response

Dear Reviewer you can find attached our replies.

Best

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

The paper presents a current topic of great interest in the field and the investigation techniques used are modern. The paper presents important scientific results from the study of biomechanical parameters using the 3D Static Strenght Prediction Program (3DSSPP) software on workers performing a practical manual material handling task, by comparing a two-armed cobot-assisted scenario with a scenario without cobot.

However, there are still somethings need to be improved and perfected before considered to be acceptance for publication:

1. Please mention in section 2. Materials and methods, subsection 2.1. Participants: Why did you choose only 5 females and 6 males as subjects? Why not an equal number of females and males? Is it possible to repeat the study with a larger number of participants?

2. From a financial standpoint, how profitable would it be to use cobots in an industrial process to minimise such risks? What would be the role of the human compared to the investment required to purchase the cobots? Is the long-term investment justified?

Author Response

Dear Reviewer you can find attached our replies.

Best

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The reviewer is now satisfied with the revised version. 

Reviewer 2 Report

Comments and Suggestions for Authors

The answer provided by the authors adressed most of the questions raised by the reviewer. It is a pity that the statistical study has been extended so little, and the authors have not considered improving the study further. Even so, the paper has merit for publication.

Reviewer 3 Report

Comments and Suggestions for Authors

The authors answered all of my previous comments. The paper has been improved. It is acceptable for publication.