Inter-Segmental Coordination during a Unilateral 180° Jump in Elite Rugby Players: Implications for Prospective Identification of Injuries

Round 1

Reviewer 1 Report

General comments:

Revise the use of punctuation, which somewhat impedes the reading. The organisation and presentation of the paper requires serious improvement. Lack of rigour in reporting the results. In the discussion, there are some assumptions made with regards to energy dissipation and force generation. This somewhat tends to draw the reader away from the main focus of this study, that is, kinematic analysis. Hence, a more comprehensive interpretation and more robust discussion of the results are warranted. In particular, it would be relevant to discuss how the kinematics of the different body parts that were measured affect postural stability during landing phase, and if one could argue any underlying strategy within this context.

Specific comments:

Line 61: Replace semicolon with comma.

Line 85: The purpose of the study could be rewritten to clearly separate research problem from objectives of the study.

Line 89: The hypothesis contains an interpretation of expected results: compensation for high torsional energy transfer – it is not clear where this is proposed to be measured in the objectives.

Line 95: Period is missing in the subheading.

Line 109: How high were the participants instructed to jump? If no instructions were given as to how high to jump, could this have an impact on the kinematics?

Line 114: How long was the rest period between trials? Did this allow for any fatigue effect to be controlled?

Line 132: Data analysis – An account of the complex process is given. It is noted that there is a broad range of heights of participants (indicated by the standard deviation). Therefore, was jump height normalised with respect to height of participants, which could be a methodological flaw if not taken into account in the data analysis?

Line 218: The legend to the Table 1 could be more explicit. For example, what is referred to knee motion, while the table is showing ICCs? Hence, it should be made clear in a subsection (data analysis or statistical analysis) how ICC translate knee motion.

Line 240: It is not clear what the values in the left and right columns stand for.

Lines 250-251: This description could be clearer if the authors had inserted markers on the graphs to delineate the landing phase. Participant A Non-Dominant Limb also seems to be out of phase during the landing phase when compared with Participant B Dominant Limb. The graphs in Figure 1 show much intra-individual and inter-individual variability; was this accounted for and/or controlled?

Lines 253-255: The legend to Figure 1 seems incomplete and requires attention to detail. The legend needs to be more informative.

Line 257: “principal” instead of “principle”.

Line 289-290: Could this be discussed within the context of motor control of postural stability during the loading phase?

Line 363: Reference 6 – typo in journal title.

Author Response

"Please see the attachment"

Author Response File: Author Response.pdf

Reviewer 2 Report

Thank you for giving me the opportunity to review this manuscript. I think that, with the exception of some minor presentation issues, the authors have done an excellent job and should be commended. 

However, i do think that more could be made of some parts of the review and these are highlighted - in addition to the minor presentation points I mentioned above - in the attached PDF.

One relatively large clanger that has been dropped however is that I could not see where your reliability data were presented or discussed - please revise this accordingly.

Comments for author File: Comments.pdf

Author Response

"Please see the attachment."

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Dear Authors,

Thank you for the opportunity to read your project. I am pleased with how you have addressed my comments and suggestions. I have read the revised version with the same interest and the points you have clarified, as well as the additions, contribute to enhance the quality of your paper. The background to the research and the discussion have been improved, and your revised version now reflects more attention to detail. Your paper will be a useful contribution to the field.

There are a couple of typos in the reference list of the revised version that I would like to flag up.

24. Mclean S, Walker, K., Ford, KR., Myer, GD., Hewett, TE., Van Den Bogert, AJ. Evaluation of a two dimensional analysis method as ligament injury a screening and evaluation tool for anterior cruciate ligament injury. Br J Sports Med. 2005;39:355-362.

25. G, Saliba, E., Diduch, DR., Hurwitz, SR., Ball, DW. Lower extremity 469 compensations following anterior cruciate ligament reconstruction. Phys Ther. 470 2000;80:251-260.

I wish you well with your research.

Author Response

Thank you again for taking the time to conduct a comprehensive review for this manuscript.  Additionally, thank you for catching these minor typos in the references, the appropriate changes have been made to rectify them.