Review Reports - Resistance Training Improves Physical Fitness and Reduces Pain Perception in Workers with Upper Limb Work-Related Musculoskeletal Disorders: A Pilot Study

Round 1

Reviewer 1 Report (New Reviewer)

I believe the authors tap into an important topic in workers with upper limb work-related musculoskeletal disorders.

This pilot study aims to evaluate the effect of structured resistance and stretching exercises on physical fitness and pain of the upper limb in workers with and without WRMD. This manuscript tries to explain in a positive way when looking at resistance, stretching exercises, and health in workers. I think some things need clarifying for the publication that will help in the overall interpretation and understanding of the results before being published within the scope of Hygiene.

Abstract

Comment 1: line 29 -Why do the authors use capital letters for Bask Scratch Test?

Comment 2: line 35 - Based on study results, the participants improved their physical fitness, but the main conclusion was "could reduce the perception of effort". Are the main conclusion of this study? The conclusion should be written based on the results and variables analysed. Please rewrite the abstract.

Materials and Methods

Comment 3: Please specify the physical fitness test order to avoid fatigue.

Comment 4: The circadian rhythm can influence physical fitness performance. How do the authors avoid this factor?

Comment 5: If the mean age is 48 years old, why do the authors use a Senior Fitness Test battery for older people?

Results

Comment 6: Table 3 – The value “8,41*10^-4” it is correct?

References

Comment 7: From 41 only 4 references with 5 or fewer years were used to justify this study. Please use recent references.

Author Response

Reviewer 1

I believe the authors tap into an important topic in workers with upper limb work-related musculoskeletal disorders.

Abstract

Comment 1: line 29 -Why do the authors use capital letters for Bask Scratch Test?

Authors: there is no reason. We change capital letter.

Authors: as suggest, we change the conclusion of abstract.

Materials and Methods

Comment 3: Please specify the physical fitness test order to avoid fatigue.

Authors: tests were administered in randomized order. the recovery time between tests was 3 minutes. We rewrote the paragraph.

Comment 4: The circadian rhythm can influence physical fitness performance. How do the authors avoid this factor?

Authors: pre- and post- evaluation were performed at the same time of the day. We specify it.

Comment 5: If the mean age is 48 years old, why do the authors use a Senior Fitness Test battery for older people?

Authors: we chose the six-senior fitness tests because it’s easy to perform in work environment; in fact, it’s quickly and require little instrumentations. In addition, the intervention group consisted of women with musculoskeletal disorders, and the six-senior seemed the best tool for evaluation.

Results

Comment 6: Table 3 – The value “8,41*10^-4” it is correct?

Authors: I confirm

References

Comment 7: From 41 only 4 references with 5 or fewer years were used to justify this study. Please use recent references.

Authors: we update the references.

Author Response File: Author Response.pdf

Reviewer 2 Report (New Reviewer)

Thank you for your research. A 14-week program requires effort and patience. I hope my suggestions help.

Comments:

Abstract, T in Test - perhaps t-test.

Please provide Cohen's d with the p=.03 to place the 3.72 value in context of meaningfulness. Abstract, I am not an editor, so please take my suggestions with that in mind, perhaps it should be 14-weeks, two-minute or 2-minute. Manuscript, I believe [ref#] is the style not (ref#). Line 63, perhaps Even so, these aspects... I do not know as I do not know if 'back school' will resonate with readers. Line 82, In light of... not sure that is the best start. It seems The aim.. is the best start and work in your supervised work-based sentence afterwards. Line 90, I am not sure Specific Exercise Training should be capitalized. Line 112, you use a ; when above you use commas. Line 155, seems an extra line space. Line 160, the sentence is awkward. It seems post-hoc should be after CR10, post-hoc. Line 204, I am not sure you need to define correlation. You do not define the other statistics in such detail. Table 2 - confidence intervals and ranges (min, max) seem of more value than SD. I would like to see both in the table. I would like to see a post - pre Cohen's d for the variables. I do see ES (Cohen's d) in some paragraphs and you told us this (lines 207-8). Are all the statistical tests in the tables explained in your methods? It is hard to keep track.

Author Response

Reviewer 2

Thank you for your research. A 14-week program requires effort and patience. I hope my suggestions help.

Comments:

Abstract, T in Test - perhaps t-test.

Authors: thanks. We change it.

Please provide Cohen's d with the p=.03 to place the 3.72 value in context of meaningfulness.

Authors: We are sorry but we do not understand the reason behind this comment.

Abstract, I am not an editor, so please take my suggestions with that in mind, perhaps it should be 14-weeks, two-minute or 2-minute.

Authors: thanks for the suggestion. We uniform in the text with 2-minutes form.

Manuscript, I believe [ref#] is the style not (ref#).

Authors: we correct the style.

Line 63, perhaps Even so, these aspects... I do not know as I do not know if 'back school' will resonate with readers.

Authors: we agree and delete back school.

Line 82, In light of... not sure that is the best start. It seems The aim.. is the best start and work in your supervised work-based sentence afterwards.

Authors: we agree and change the last paragraph.

Line 90, I am not sure Specific Exercise Training should be capitalized.

Authors: as suggest, we change it.

Line 112, you use a ; when above you use commas.

Authors: you agree. We uniform with comma.

Line 155, seems an extra line space.

Authors: we delete it

Line 160, the sentence is awkward. It seems post-hoc should be after CR10, post-hoc.

Authors: we change the paragraph to better explain measures.

Line 204, I am not sure you need to define correlation. You do not define the other statistics in such detail.

Authors: thanks. We agree and delete the sentence.

Table 2 - confidence intervals and ranges (min, max) seem of more value than SD. I would like to see both in the table.

Authors: While we agree that the range can be a useful information, we do not see the point to present the confidence intervals. Table 2 describes the sample characteristics. We do not want to do any kind of inference on these variables. We add only the ranges on table.

I would like to see a post - pre Cohen's d for the variables. I do see ES (Cohen's d) in some paragraphs and you told us this (lines 207-8).

Authors: We are sorry, but we cannot understand the comment. As we stated in the statistics paragraph, we calculated the Cohen’s d for the significant variables. Do you want also ES for non-significant variables?

Are all the statistical tests in the tables explained in your methods? It is hard to keep track.

Authors: I confirm. All statistical tests are explained in methods.

Author Response File: Author Response.pdf

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

The purpose of this pilot study was to 1) evaluate the effect of supervised exercises on physical fitness and pain of the upper limb and 2) evaluate the rate of change in pain and performance. This pilot study demonstrated the potential use of SET to improve pain and enhance performance. However, it is limited in sample (13) for statistical analysis. The use of statistical model (t-test) is questionable when multiple factors were used to discuss the results. The design of training protocol might create additional confounding factors that increase heterogeneity of the results. Additional comments are listed below.

Abstract

-The type of career of those participants should be mentioned.

Introduction

-The term “specific training program” is not well defined. Is it strengthening? Is it stretching? Or both.

-Hypothesis should be stated after the aims of the study.

Methods

-For the resistance training, how many participants used elastic band? How many of them used free weight? Resistance training using elastic band or free weight potentially has different impacts on the effect of training.

-For the exercise training protocol, did different participants receive exercises on different muscles? To modify the intensity, different repetition ranges were prescribed, would this protocol create different exercises efforts/loads to different participants?

-Again, the specific exercise training (SET) is not well defined in the methods. It is likely that the content of the SET was varied due to different body parts were affected by WRMDs across participants. Could the potential confounding variations within the training protocol be controlled in the analysis?

-What is the rationale to perform SET after week 4?

-In the 2.8 Timeline, the SET was started at week 6, which is not the same as in the 2.4 Exercise program section. When was the SET started?

-Why Kruskal-Wallis test was conducted to examine the difference on disability and pain?

-If participants were stratified in respect to the presence or absence of WRMDs, should 2x2 ANOVA be performed instead of separate t-tests?

Discussion

-it is unclear why most of the discussion are only focusing on the effect of SET. For instance, “the improvement in performance and reduction of pain in body area with WRMDs were higher due to the SET”. In the exercise training protocol, both RE and SET were performed, why the portion of the RE is de-emphasized in the discussion? Should the effect of change in performance or pain be due to the combination of RE and SET?

-As participants’ stratification based on the presence of WRMDs seems an important part of the discussion, should 2x2 ANOVA be a better statistical method to analyze the data?

-For the sub-group analysis with participants with upper limb WRMDs, it is unclear if the study has enough samples/power to conduct such analysis and to draw subsequent conclusion?

Conclusions

-Please further explain the statement, “…general variable, as total volume, could be more important than specificity respect to WRMDs.” What does the volume mean in this statement? Did any results provide evidence to support the content?

Minor comments:

-Table 1, the use of “SPE” is confusing. Is SPE the same as SET? If yes, please consider using SET in the table.

Reviewer 2 Report

ijerph-1695258

Reviewer comments

In the submitted manuscript, the author(s) examined the impact of a resistance training program on the physical fitness and pain perception of a group of women with upper limb WRMDs. A group of 16 female workers were submitted to a work-based stretching and resistance training program that lasted for 14 weeks. The major outcome of the study was that the intervention improved the physical fitness of the participants. However, there was a limited effect on WRMDs pain.

The study is an interesting perspective of how work-based physical activity can deal occupational musculo-skeletal disorders. However, there a number of topics that should be considered. These topics are presented in the following comments.

General Comments

English should be improved throughout the text. See, for example L55, L58 & L331 (. However,), L67 (to relief pain), L145 (muscles), L161 (indicate which[?] body part), L230 (flexibility,) L342 (is well), among others.
Parts of the text that can be omitted, i.e. L27 (Differences were verified with T test), L191-193 (The correlation coefficient ranges from -1 to +1. A value of 1 implies the 191 perfect linear relationship between the two variable X and Y, while a 0 value indicates no 192 correlation), L216-217 (Kruskal-Wallis test was conducted to examine the difference on disability and pain 216 according to the physical activity level of participants).
Methods: Participants seem to be a convenience sample examined in a pilot study. However, its size, although evidence is provided about its adequacy, is still small for the design of the study (group comparisons made for lateral differences). In addition, keep a constant terminology: it should be either “injured/non-injured” or “healthy/unhealthy” throughout the manuscript. This applies also for “SET” (L128-129) and “SPE” (L137-138).
Discussion: Further elaboration is needed based on past research findings.

Specific comments

Abstract

See the respective General Comments.

Introduction

See the respective General Comments.
L82: “difference” instead of “rate of change”.
L79-83: Tables 4 and 5 adds more context to the purpose of the study. Thus, the rationale for the study, its purposes and the respective hypotheses should be rewritten.

Methods

See the respective General Comments.
L104-109: Was arm dominance considered? Why?
L123-132: Provide additional details about the “individualized… linear manner” that “…increased volume…throughout the program…”. Furthermore, there is a large range in the prescribed training volume (i.e. from 10 to 30 s). Could this be a limiting factor for the outcome of the study?
L127: Provide also additional details for the warm up.
L127: Where there dynamic or static stretching exercises? Why?
L139-152: Provide the reliability scores of the measurements. About the isometric handgrip strength: which dynamometer was used?
L152: Delete “please refer” and replace with “according”.
L169-174: Merge this subsection into 2.1
L175-201: Initiate the paragraph with the normality tests. In addition, do you refer to Cohen’s d in L194?

Results

See the respective General Comments.
Table 2: Omit sex (it is also defined in Section 2). Also: add count (n) per PA category. Finally, define in the medical history if it is one case per person.
Table 3: Type in 2 decimals in column ‘r Sign’; Upper limb VAS: SD is almost the full range of the VAS; provide the units for the last four parameters depicted in Table 3.
Table 5: Difference data are missing for the middle two parameters.

Discussion

L292-310: See the respective General Comment.
Provide the expected muscular adaptations due to the training stimuli and how these adaptations can interpret the findings of the study.