Absolute Reliability and Concurrent Validity of the Modified Goniometric Platform for Measuring Trunk Rotation in the Sitting Position

Round 1

Reviewer 1 Report

The main objective of this paper is to evaluate some parts of the reliability and validity of a transversal goniometer for evaluation of the rotational movement of the trunk. The subject could be of interest, but there are very important methodological weaknesses, both in the methodology design and in the analyses and interpretation of the results, which do not counsel its publication in the present form.

 

Specific comments:

Title: What type of reliability (absolute, relative…) and what type of validity (convergent, construct, concept…) were studied?

 

Abstract: The abstract should be rewritten according to new text.

 

Introduction:

- In general, this section should be summarized. The paragraphs are too long according to the purpose of each of them.

- Lines 77-81: I do not agree. The method of assessing trunk rotation with a goniometric platform needs standardized procedures and training (the Familiarisation and testing subsection is a good example).

- Lines 82-84: Please, detail the data (example: what is reliability of 0.80?). Also, if the reliability of the goniometric platform has been demonstrated, what is the justification for the current research?

 

Materials and methods:

- No a priori sample size, based on the data analyses, was estimated. This is a very important weakness of the research. Furthermore, the external validity of the sample is questionable. Movement features depend on sex, and it is hard to assume that 8 male or 9 female can represent a broad target population. It is insufficient to include this as a limitation of the study.

Finally, the clinical applicability of the results is unknown. All volunteers were healthy, and the background of the paper was based on the pathological characteristics of a modified trunk rotation. It is insufficient to include this as a limitation of the study.

The inclusion/exclusion criteria must be specified.

- Lines 97-98: Why only 40 minutes between the evaluations? Please, explain the consequences of this approach for the interpretation of the results and their application in clinical setting. It is insufficient to include this as a limitation of the study.

- Lines 107-114: This reviewer was unable to identify the distance between the MGP and the camera. In general, more information about the validity protocol is required.

- Lines 111-113: Please, explain what r = 0.94 is and how it was determined.

- Figure 1: Parts of the hands and trunk cannot be observed.

- Line 130: How many are several trunk rotations?

- Figure 2: Again, some parts cannot be seen. For example, the assistant.

- Statistical analysis: This is one of the main weaknesses of the paper.

Koo and Li's reference and classification system (reference 18) can be relocated here.

SEM and MDC values should be provided.

How were the Bland-Altman plots analyzed?

- Figure 3: Is it necessary? It can be removed, in my opinion.

 

Results:

- Subsection 3.3: Is the title “Validity of the two instruments” correct? I thought that validity was studied only for MGP.

- Bland-Altman plots: Please, report and interpret the limits of agreement, some possible outliers, possible bias for higher range of motion values (see Figure 3 on the right).

 

Discussion:

- In general, this section should add information according to new results and this review.

- The first paragraph should be removed or replaced.

- Lines 285-288: The authors support the clinical application of these results, but this approach should be reinterpreted according to this review.

- The difficulties in achieving high reliability in the transverse plane movements are well documented. Please, check these papers: doi: 10.3390/diagnostics10020080 , doi: 10.3390/s19071555

- Lines 289-292: As previously commented, I do not agree with these advantages. In my opinion, the protocol should be well known and explained, prior knowledge is crucial in clinical settings,…

 

Conclusion:

The conclusion should be rewritten according to the review.

 

For these reasons, I cannot recommend publication of the article in is present version.

Author Response

Applied Science,

Absolute Reliability and Concurrent Validity of the Modified Goniometric Platform for Measuring Trunk Rotation in the Sitting Position

Dear Reviewers,

Thank you for your useful comments and suggestions on the language and structure of our manuscript. We have carefully modified this manuscript according to each comment given, and detailed corrections are listed below point by point:

1. Title: What type of reliability (absolute, relative…) and what type of validity (convergent, construct, concept…) were studied?

In this research, absolute reliability (absolute agreement) and concurrent validity were studied. According to the suggestion, we changed the title “Reliability and Validity of the Modified Goniometric Platform for Measuring Trunk Rotation in the Sitting Position” to “Absolute Reliability and Concurrent Validity of the Modified Goniometric Platform for Measuring Trunk Rotation in the Sitting Position”.

2. Abstract: The abstract should be rewritten according to the new text.

In the abstract, we did a little revision. We did not add new information which is beyond the abstract.

3. Introduction:

1) In general, this section should be summarized. The paragraphs are too long according to the purpose of each of them.

According to the comments, we did some revisions in this part.

2) Lines 77-81: I do not agree. The method of assessing trunk rotation with a goniometric platform needs standardized procedures and training (the Familiarisation and testing subsection is a good example).

Yes, we agreed with this suggestion, and we did some revisions. We changed “The goniometric platform is an easy, intuitive reading instrument that does not require ‘handholding’. Sarioglu and Pekyavas [17] initially used it to assess trunk rotation in the sitting position. Compared to previous instruments, the goniometric platform has two apparent strengths as a novel tool for measuring trunk rotation. First, it is straightforward and can easily be applied without in-depth anatomical knowledge. Second, it is cheaper.” to “The goniometric platform, as a novel tool, is an easy-to-use and low-cost equipment to assess trunk rotation in the sitting position, which was initially used by Sarioglu and Pekyavas [17].”

3) Lines 82-84: Please, detail the data (example: what is the reliability of 0.80?). Also, if the reliability of the goniometric platform has been demonstrated, what is the justification for the current research?

① We checked back the paper which we cited, it is Cronbach’s Alpha coefficient(α), α = 0.8. However, it did not report the type of reliability. We revised lines 82-84. Please check it.

② The current research was aim to provide the reliability and validity evidence of the goniometric platform which has been modified by our research team. In lines 83 and lines 84-87, we mentioned the limitation of the application of the goniometric platform in practice, such as validity missing, ergonomic effects not a consideration and negative feedback from the participants. Therefore, the instrument need further improvement.

4. Materials and methods:

1）No a priori sample size, based on the data analyses, was estimated. This is a very important weakness of the research. Furthermore, the external validity of the sample is questionable. Movement features depend on sex, and it is hard to assume that 8 male or 9 female can represent a broad target population. It is insufficient to include this as a limitation of the study.

① The sample size was calculated based on the fixed n = 3 (number of measurements), ?₀ = 0.7(above 0.7 would be considered acceptable), ?₁ = 0.80 (above 0.8 would be considered good), α =0.05 and β =0.8 in this study, therefore, we got the sample size from the 12.8 (13) to 79.7 (80) by referring the table [1]. The minimum sample size of 13 was considered in this research. Seventeen participants were recruited in the final, and all findings showed good to excellent evidence based on this sample. In addition, Furness mentioned that a sample size of at least 15–20 is considered adequate for reliable studies which collect continuous data [2], and this was consistent with our sample size.

② Yes, I agreed with the opinion that women are more flexible than male in general. However, gender was not a factor which should be considered in this research based on our research purpose. The primary purpose of this study is to compare between and within raters by using the same instrument to measure the trunk rotation as well as to compare the concurrent validity of this novel instrument. We may consider it in future research.

③ Yes, I agreed with the opinion of “8 males or 9 females is not insufficient to represent a broad target population” duo to the population is very huge with different age groups. However, we want to explain that gender or even age group were not the factors we considered here. Therefore, we considered it a limitation of this research. Our point was supported by the previous studies [2, 3].

2)Finally, the clinical applicability of the results is unknown. All volunteers were healthy, and the background of the paper was based on the pathological characteristics of a modified trunk rotation. It is insufficient to include this as a limitation of the study.

Yes, the clinical applicability of the results is unknown, but it may be worth doing further study. We are very sorry to make you confused about it. According to the suggestions, we rewrite the first paragraph of the background, so it could help improve clarity.

3)The inclusion/exclusion criteria must be specified.

According to the comments, we added the related below information:

The participants were excluded from this study if they had (1) a history of fracture or traumatic injuries of the spine and upper limbs; (2) a history of orthopedic surgery in the upper body; (3) any orthopedic or neurological problems in the upper body.

This information can be found in lines 93-95.

4) Lines 97-98: Why only 40 minutes between the evaluations? Please, explain the consequences of this approach for the interpretation of the results and their application in clinical setting. It is insufficient to include this as a limitation of the study.

① In previous evidence, there was no exact evidence about how long should use between the test session and the re-test session. Some studies pointed to 5-15 minutes within day test [4], and even some study even examined the between days reliability (48h, 72h) [5]. In this study, 17 participants were tested in the test session. The re-test session was performed after all participants did the test session, and the interval of each participant was around 40 minutes.

② Reliability can be tested within a day and between days. In this study, we only did reliability within days, but we could know whether it could get a similar result between days. Therefore, this could be considered one limitation of the study [4]. 

5) Lines 107-114: This reviewer was unable to identify the distance between the MGP and the camera. In general, more information about the validity protocol is required.

Actually, the distance between the MGP and the camera will not affect the angle. The key components are that the camera should set perpendicular to the table and cover the MGP, the participant’s maximum left and right trunk rotation, an extension of both arms and hands at different angles, and the table and goniometric platform., and that information we have mentioned in the text.

6) Lines 111-113: Please, explain what r = 0.94 is and how it was determined.

① r is the correlation coefficient, r= 0.94 means that there is a strong and positive relationship between the two measurements by the video analyst.  

② 17 samples was analysed twice by the video analyst, then the Pearson correlation was conducted between these two sets of data. 

7) Figure 1: Parts of the hands and trunk cannot be observed.

According to the suggestion, we picked up another image and changed it. Participants were instructed to sit upright. The trunk has been captured by the vertical camera, so it may shield by the head and shoulder. 

8) Line 130: How many are several trunk rotations?

Each participant practised three trunk rotations [6]. According to the comment, the information was added in the text (please check line 163).

9) Figure 2: Again, some parts cannot be seen. For example, the assistant.

The whole body of the assistant is not our interest, and the critical part is their hands which are put on the area of participants’ pelvic. Therefore, our camera setting was on purpose to set about this.

-Statistical analysis: This is one of the main weaknesses of the paper.

10) Koo and Li's reference and classification system (reference 18) can be relocated here.

According to the suggestion, we relocated it.

11) SEM and MDC values should be provided.

According to the comment, we provided the SEM and MDC in the inter and intra-reliability table. The detailed information can be checked in Table 1 and Table 2.

12) How were the Bland-Altman plots analyzed?

In statistical analysis, all quantitative data in this study were analysed using version 22 of SPSS statistical software (IBM, Chicago, IL, USA). The difference and mean were computed at first, and then we performed a simple scatter plot perform.

13) Figure 3: Is it necessary? It can be removed, in my opinion.

According to the comment, we removed it.

5. Results:

1) Subsection 3.3: Is the title “Validity of the two instruments” correct? I thought that validity was studied only for MGP.

Yes, I agreed with this opinion. We revised it to “Validity”.

2) Bland-Altman plots: Please, report and interpret the limits of agreement, some possible outliers, possible bias for higher range of motion values (see Figure 3 on the right).

 According to the suggestions, we added the 95% limits agreement in lines 270-271.

Figure 3 graphically demonstrates the majority of data points close to the mean difference and within the 95% limits agreement even though 1-2 points are over the range of 95% level of agreement.

6. Discussion:

1)In general, this section should add information according to new results and this review.

According to the comment, we did a revision in this part. We did not add the new result which is beyond the discussion.

2) The first paragraph should be removed or replaced.

According to the comment, we removed it.

3) Lines 285-288: The authors support the clinical application of these results, but this approach should be reinterpreted according to this review.

According to the comment, we changed our expression to “The MGP is valid, and it also shows a smaller variance than that observed using other digital goniometers. Therefore, the MGP may have more possibility to be applied in assessing the trunk rotation.” This information can be found on lines 413-415.

 

4) The difficulties in achieving high reliability in the transverse plane movements are well documented. Please, check these papers: doi: 10.3390/diagnostics10020080, doi: 10.3390/s19071555

Yes, we agreed with it. We carefully checked this paper, and this paper was focused on the range of motion of the neck. Even if it has difficulties in achieving high reliability in the transverse plane movements, the result also showed that high correlations were detected between methods in both groups on the sagittal and frontal planes (r > 0.9) in this paper.

5) Lines 289-292: As previously commented, I do not agree with these advantages. In my opinion, the protocol should be well known and explained, prior knowledge is crucial in clinical settings.

According to the comment, we rephrased this sentence to “The advantage of the MGP is that it is a cost-effective, instantly read, portable tool. It is a relatively straightforward tool that can be used by trained individuals with or without anatomical or related knowledge.”

7.Conclusion:

The conclusion should be rewritten according to the review.

According to the suggestion, we did a revision in this part.

1. Walter, S.; Eliasziw, M.; Donner, A. Sample size and optimal designs for reliability studies. Statistics in medicine. 1998, 17, 101-110.
2. Furness, J.; Schram, B.; Cox, A.J.; Anderson, S.L.; Keogh, J. Reliability and concurrent validity of the iPhone® Compass application to measure thoracic rotation range of motion (ROM) in healthy participants. PeerJ. 2018, 6, e4431.
3. Feijen, S.; Kuppens, K.; Tate, A.; Baert, I.; Struyf, T.; Struyf, F. Intra-and interrater reliability of the ‘lumbar-locked thoracic rotation test’in competitive swimmers ages 10 through 18 years. Phys Ther Sport. 2018, 32, 140–144.
4. Getnet, M.G.; Jember, G.; Janakiraman, B. Inter-and intra-observer reliability of scoliogauge app to assess the axial trunk rotation of scoliosis: Prospective reliability analysis study. Int J Surg. 2020, 27, 5–9.
5. Johnson, K.D.; Kim, K.; Yu, B.; Saliba, S.A.; Grindstaff, T.L. Reliability of thoracic spine rotation range-of-motion measurements in healthy adults. J Athl Train. 2012, 47, 52–60.
6. Cools, A.M.; De Wilde, L.; Van Tongel, A.; Ceyssens, C.; Ryckewaert, R.; Cambier, D.C. Measuring shoulder external and internal rotation strength and range of motion: comprehensive intra-rater and inter-rater reliability study of several testing protocols. Journal of shoulder and elbow surgery. 2014, 23, 1454-1461.

 

 

 

 

 

 

Author Response File: Author Response.docx

Reviewer 2 Report

1. There were 17 participants in this study.

Please provide the basis for calculating the research sample size.

 

 

2. With convenient sampling, it is difficult to generalize the study. 

 

3. For statistical methods, please provide a reference for previous studies on lines 153 to 159.

4. In Figure 1, please provide a scientific rationale for why you need to do a 40-minute interval re-test.

 

 

5. Reorder the names of the x- and y-axes for Figure 3 and Figure 4.

 

 

 

Author Response

Applied Science,

Absolute Reliability and Concurrent Validity of the Modified Goniometric Platform for Measuring Trunk Rotation in the Sitting Position

Dear Reviewers,

Thank you for your useful comments and suggestions on the language and structure of our manuscript. We have carefully modified this manuscript according to each comment given, and detailed corrections are listed below point by point:

1. There were 17 participants in this study.

Please provide the basis for calculating the research sample size.

1)The sample size was calculated based on the fixed n = 3 (number of measurements), ?₀ = 0.7(above 0.7 would be considered acceptable), ?₁ = 0.80 (above 0.8 would be considered good reliability), α =0.05 and β =0.8 in this study, therefore, we got the sample size from the 12.8 (13) to 79.7 (80) by referring the table [1]. The minimum sample size of 13 was considered in this research. Seventeen participants were recruited in the final, and all findings showed good to excellent evidence basin on this sample.

2) In addition, Furness mentioned that a sample size at least 15–20 is considered adequate for reliable studies which collect continuous data [2], and this was consistent with our sample.

2. With convenient sampling, it is difficult to generalize the study. 

 Yes, I agree with this point. It is difficult to generalize this study to the vast population (different age groups and gender) by using convenient sampling. However, we want to explain that the primary purpose of this study is to compare between and within raters by using the same instrument to measure the trunk rotation as well as to compare the concurrent validity of this novel instrument.

In a previous study, this factor could be considered one of the limitations. Our point was supported by the previous studies [2, 3].

3. For statistical methods, please provide a reference for previous studies on lines 153 to 159.

According to the comment, we added the reference. This can be found on line 188.

4. In Figure 1, please provide a scientific rationale for why you need to do a 40-minute interval re-test.

In previous evidence, there was no exact evidence about how long should use between the test session and the re-test session. Some studies pointed 5-15 minutes within day test [4], and even some studies even examined the between days reliability (48h, 72h) [5]. In this study, 17 participants were tested in the test session. The re-test session was performed after all participants did the test session, and the interval each participant went through the test and re-test session was around 40 minutes.

5. Reorder the names of the x- and y-axes for Figure 3 and Figure 4.

According to the comment, we reordered the name of the x- and y-axes for Figure 3 and Figure 4.

Dear reviewer,

We noticed that your moderate English change is required according to your comments. We had gone through the proofreading procedure (Elsevier author services) before we submitted this manuscript to the Journal of Applied Science. Is it possible to give us specific comments if some language still needs to improve? We will be appreciated it.

Thanks!

 

Shanshan wei

2^nd August 2022

1. Walter, S.; Eliasziw, M.; Donner, A. Sample size and optimal designs for reliability studies. Statistics in medicine. 1998, 17, 101-110.
2. Furness, J.; Schram, B.; Cox, A.J.; Anderson, S.L.; Keogh, J. Reliability and concurrent validity of the iPhone® Compass application to measure thoracic rotation range of motion (ROM) in healthy participants. PeerJ. 2018, 6, e4431.
3. Feijen, S.; Kuppens, K.; Tate, A.; Baert, I.; Struyf, T.; Struyf, F. Intra-and interrater reliability of the ‘lumbar-locked thoracic rotation test’in competitive swimmers ages 10 through 18 years. Phys Ther Sport. 2018, 32, 140–144.
4. Getnet, M.G.; Jember, G.; Janakiraman, B. Inter-and intra-observer reliability of scoliogauge app to assess the axial trunk rotation of scoliosis: Prospective reliability analysis study. Int J Surg. 2020, 27, 5–9.
5. Johnson, K.D.; Kim, K.; Yu, B.; Saliba, S.A.; Grindstaff, T.L. Reliability of thoracic spine rotation range-of-motion measurements in healthy adults. J Athl Train. 2012, 47, 52–60.

 

 

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The paper has improved and the authors were careful with the changes. Some minor weaknesses remain.

- Regarding the sample size, the authors stated “The sample size was calculated based on the fixed n = 3 (number of measurements), ?0 = 0.7(above 0.7 would be considered acceptable), ?1 = 0.80 (above 0.8 would be considered good), α =0.05 and β =0.8 in this study, therefore, we got the sample size from the 12.8 (13) to 79.7 (80) by referring the table [1]. The minimum sample size of 13 was considered in this research. Seventeen participants were recruited in the final, and all findings showed good to excellent evidence based on this sample. In addition, Furness mentioned that a sample size of at least 15–20 is considered adequate for reliable studies which collect continuous data [2], and this was consistent with our sample size”. This information should be included in the paper.

- An explanation of how SEM and MDC were calculated should be included in the Statistical analysis section.

- At least, reinforce Bland-Altman plot analysis with a bibliographic reference in the Statistical analysis section.

Author Response

Applied Science,

Absolute Reliability and Concurrent Validity of the Modified Goniometric Platform for Measuring Trunk Rotation in the Sitting Position

Dear Reviewers,

Thank you for your valuable comments and suggestions on the language and structure of our manuscript. We have carefully modified this manuscript according to each comment given, and detailed corrections are listed below point by point:

1. Regarding the sample size, the authors stated “The sample size was calculated based on the fixed n = 3 (number of measurements), ���0 = 0.7(above 0.7 would be considered acceptable), ���1 = 0.80 (above 0.8 would be considered good), α =0.05 and β =0.8 in this study, therefore, we got the sample size from the 12.8 (13) to 79.7 (80) by referring the table [1]. The minimum sample size of 13 was considered in this research. Seventeen participants were recruited in the final, and all findings showed good to excellent evidence based on this sample. In addition, Furness mentioned that a sample size of at least 15–20 is considered adequate for reliable studies which collect continuous data [2], and this was consistent with our sample size”. This information should be included in the paper.

According to suggestions, this information was added to the 2.4 sample size.

2. An explanation of how SEM and MDC were calculated should be included in the Statistical analysis section.

 

According to suggestions, this information on how to calculate SEM and MDC was added the related reference in the statistical analysis section.

 

3. At least, reinforce Bland-Altman plot analysis with a bibliographic reference in the Statistical analysis section.

 

According to suggestions, I added the related reference in this part.

 

 

Thanks!

Shanshan Wei

20^th August 2022

 

 

 

 

Author Response File: Author Response.docx

Reviewer 2 Report

I read the revised manuscript.

1.   But the manuscript was big problem for the convenient sampling.

2. With convenient sampling, it is difficult to generalize the study. 

Author Response

Applied Science,

Absolute Reliability and Concurrent Validity of the Modified Goniometric Platform for Measuring Trunk Rotation in the Sitting Position

Dear Reviewers,

Thank you for your comments and suggestions on the language and structure of our manuscript. We have carefully modified this manuscript according to each comment given, and detailed corrections are listed below point by point:

1.But the manuscript was big problem for the convenient sampling. With convenient sampling, it is difficult to generalize the study. 

1) Our research team showed different opinions about it. We insist that convenient sampling should not be considered the “big problem” in this study design. Meanwhile, we agreed with the part of the comments about convenient sampling that cannot be generalised. Our reasons are listed below:

① The probability (random sampling) and non-probability (convenient sampling) sampling were selected  depending on the different objectives of the study specific [1]. In this study, our purpose is to compare the between and within raters by using the same novel instrument to measure the trunk rotation as well as to compare its validity to the other valid instrument. Our research team first modified this goniometer platform, and it is very urgent to prove whether this novel instrument can be used first. Therefore, the aim of this study is not first considered to generate the population’s result.

② Although convenient sampling has drawbacks, it was considered the more suitable sampling method in this study. Etikan et al. mentioned that “convenient sampling is practical especially when randomisation is impossible like when the population is vast; it can be helpful when the researcher has limited resources, time and workforce; it can also be used when the research does not aim to generate results that will be used to create generalisations pertaining to the entire population.[2]” In this study, our research team considered the resources, the time, the research purpose, and thus the convenient sampling was finally considered.

③ In addition, our research team considered convenience sampling cannot be generalised to the population as a limitation, supported by previous studies [3-4]. We mentioned this limitation in the final part of the discussion.

Thanks!

Shanshan Wei

20^th August 2022

 

Reference

1. Farrokhi, F. and A. Mahmoudi-Hamidabad, Rethinking convenience sampling: Defining quality criteria.Theory & Practice in Language Studies, 2012. 2(4).
2. Etikan, I., S.A. Musa, and R.S. Alkassim, Comparison of convenience sampling and purposive sampling.American journal of theoretical and applied statistics, 2016. 5(1): p. 1-4.
3.          Furness, J.; Schram, B.; Cox, A.J.; Anderson, S.L.; Keogh, J. Reliability and concurrent validity of     the iPhone® Compass application to measure thoracic rotation range of motion (ROM) in healthy participants. PeerJ. 2018, 6, e4431.
4.          Feijen, S.; Kuppens, K.; Tate, A.; Baert, I.; Struyf, T.; Struyf, F. Intra-and interrater reliability of the ‘lumbar-locked thoracic rotation test’in competitive swimmers ages 10 through 18 years. Phys Ther Sport. 2018, 32, 140–144.

 

 

Author Response File: Author Response.docx