Fall Risk in Older Adults Transitioning between Different Flooring Materials

Round 1

Reviewer 1 Report

The last paragraph of introduction before the statement of the aims/purposes of the study should be moved to discussion. Just provide a more general overview of the literature, without detailing results, p-values, statistical significances and related stuff. 

May I have missed it, but it is not clear to me the kind of sample recruitment authors performed. Also the sample size: is there a scientific rational for it (for instance, an a priori sample size power analysis)? Authors should demonstrate that their study is sufficiently powered to capture an adequate effect size. 

Could authors provide their results also in terms of effect sizes?

Author Response

1. The last paragraph of introduction before the statement of the aims/purposes of the study should be moved to discussion. Just provide a more general overview of the literature, without detailing results, p-values, statistical significances and related stuff. Revision: Thanks for the review. The last paragraph includes the arguments that three has been lack of understanding of the gait characteristics of older adults transitioning between different flooring coverings, which is a critical information to explain to a reader why this study needs to be conducted (i.e., rationale of this study). Yet, the paragraph includes the numerical values (i.e., participants’ age Mean and SD) that come from other studies. Although the data are not directly associated with gait characteristics, a reader may be confused to consider them as statistical analysis results. Therefore, we revised it to delete the numerical values so that the introduction section appears to include general information only. 2. May I have missed it, but it is not clear to me the kind of sample recruitment authors performed. Also the sample size: is there a scientific rational for it (for instance, an a priori sample size power analysis)? Authors should demonstrate that their study is sufficiently powered to capture an adequate effect size. Revision: We appreciate your advice. A convenience sampling method was used, and a sample size justification has been added accordingly. 3. Could authors provide their results also in terms of effect sizes? Revision: Thanks! We added the effect sizes.

Reviewer 2 Report

Many thanks for the clear presentation of the research objectives. However, some justifications can be added to your valuable topic. 

1- Can you provide stronger justification of why the sample size is (14) for both the older and younger participants? 

2- Have you checked the statistical distribution of the time in the stages throughout the experiment? (i.e. also the slip and trip probability).

3- some of the paragraphs require editing to fix some grammatical issues  

Good luck in your publication. 

Author Response

1. Can you provide stronger justification of why the sample size is (14) for both the older and younger participants? Revision: Thanks for your review. A sample size justification has been added accordingly. 2. Have you checked the statistical distribution of the time in the stages throughout the experiment? (i.e. also the slip and trip probability). Revision: We appreciate your comment. We measured the time while the participants were transitioning/walking on each floor condition, which contributed to calculating the velocity of heel contact and the transitional acceleration of the whole body center-of-mass (COM). The revised result section includes detailed descriptions of the velocity and the likelihood of slipping for different walking floor conditions. 3. Some of the paragraphs require editing to fix some grammatical issues. Revision: Thank you for your advice. It has been done accordingly.

Round 2

Reviewer 1 Report

Authors have addressed all comments in a satsfactory way. 

Reviewer 2 Report

Thanks to the authors as they have addressed most of the comments. However, I didn’t find any type(s) of injuries that can be caused from the transitioning movement from carpet-vinyl or vinyl-carpet and what are the precautions to mitigate  any anticipated injuries. The paragraph after Table 2 had indicated a statistical significance with regards the slipping (The ANOVA results indicated statistically significant differences (F3,73=6.25, P=0.0008,η2=0.149) in the heel contact velocity between the different floor conditions). However, in section 3.4, it was indicated the opposite. Can you please provide a clear justification for this contradiction. Thanks

Author Response

Reviewer 2: I didn’t find any type(s) of injuries that can be caused from the transitioning movement from carpet-vinyl or vinyl-carpet and what are the precautions to mitigate any anticipated injuries. Authors: We did not encounter any research participants falling or getting fall-related injuries while conducting the study in the lab. All participants were instructed to wear safety harness. The primary research objective is to advance knowledge about how the transitions affect the gait characteristics, instead of how people actually fall on the floor. Thus, we have no fall accident/injury report to include in this paper; yet, the literatures about fall-related injuries on various floor coverings have been added in the discussion section instead. Ideas for fall prevention interventions (including “the precautions to mitigate any anticipated injuries”) were adequately addressed in the discussion section. Please refer to the discussion section. Discussing further detailed, extended intervention ideas would lead to overstating this study’s findings and go beyond the scope of this study. Reviewer 2: The paragraph after Table 2 had indicated a statistical significance with regards the slipping (The ANOVA results indicated statistically significant differences (F3,73=6.25, P=0.0008,η2=0.149) in the heel contact velocity between the different floor conditions). However, in section 3.4, it was indicated the opposite. Can you please provide a clear justification for this contradiction? Authors: They are not contradictory results as they are just different measurements; “the paragraph after Table 2” is for the objective data (walking characteristics) and “the section 3.4” is for the subjective data (participants’ perceived risk of slipping/tripping). The relationship between the objective data and the subjective data of the participants was adequately addressed in the discussion section. Please refer to the following excerpts: “Although the increasing probability of a slip or trip accident was found throughout the changes in gait parameters, the older participants were not aware of the danger posed by transitioning between floor surfaces as indicated by their subjective ratings (i.e., perception of slipping, tripping and falling). Therefore, older adults should be made aware of the danger of slipping and tripping while transitioning between different floor surfaces, perhaps through use of a caution sign or exercise programs. For future research, it would be beneficial to investigate how much the safety interventions (e.g., a caution sign and training) influence the gait parameters and the perception of danger during transitioning….” Thank you for reviewing this manuscript.

Round 3

Reviewer 2 Report

Thanks for your consideration to my comments. 
Good luck for your next scientific research.