A Proposed Method for Evaluating Drop Jump Performance with One Force Platform
Round 1
Reviewer 1 Report
The manuscript is very interesting and very well written. I have some minor concerns though.
The text did not mention any exclusion criteria. Knee or hip previous surgery, injuries?
Please, provide a sample size calculation.
"Following a brief (~10 minutes) warm-up comprised of dynamic stretching and sub-maximal jumping (countermovement jumps and rebound jumps)" - Please, provide a reference. Could this 10 min warm-up change the performance during the actual test? Please, state this possible limitation in your methods.
"Touchdown 142 velocity was then estimated from box height based on the conservation of mechanical energy principle as the square 143 root of 2 × 9.81 × box height (in m)." Please, provide a reference.
The authors might explore the results during the text. A single paragraph seems to provide less information than necessary for readers' flow.
Please, expand your limitation paragraph. Only male participants were assessed. No reports of injury were provided. Are the results valid for any population?
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
General Comments
This is an interesting study, assessing the criterion validity of evaluating drop jump (DJ) performance with one force platform (1FP). The authors hypothesised that the 1FP method would be a valid alternative to the criterion of two force platform (2FP) method. The participants were 26 male sports science students with a mean age of 24 years from a variety of sports. They performed three DJs, from a 0.30 m and 0.40 m high box, on two adjacent force platforms. The drop height, touchdown velocity and several performance variables were calculated using the 2FP and 1FP methods. The results of this study demonstrated no fixed or proportional bias between for any variable reported for DJs performed from both box heights. The mean drop height was, on average 10% and 14% lower, respectively, than the 0.30 m and 0.40 m box height that the participants started on. The authors suggested that this discrepancy highlights the importance of accounting for drop height when conducting DJ assessments. The main conclusion of this study was that the 1FP method of evaluating DJ performance is a valid alternative to the criterion 2FP method and could be embedded into automated force analysis software for researchers and practitioners to utilise.
The manuscript is generally well written. However, the design of this paper should be little improved before publishing.
1. The authors should be to describe more detail the participants (sports science students) – In which sports they were involved?; Did they have preliminary experience to use DJs?; Exclusion criteria (acute and chronic injuries, low back pain, etc.).
- I suggest to restructure the Material and Methods as follows: 2.1. Participants; 2.2. Experimental Design; 2.3. Statistical Analysis.
- In my opinion, it is obligatory to add as a limiting factor of the study the fact, that only young male, trained (sports science students) were measured in this study, and, therefore, the results of this study cannot be transferred to females, physically less active and older subjects. This notice should be mentioned and analyzed at the end of DISCUSSION.
Specific Comments
Abstract
Page 1, line 39.
- Please add information that participants were young males.
- Materials and Methods
- Please restructure the Material and Methods as follows: 2.1. Particiapants; 2.2. Experimental Design; 2.3. Statistical Analysis
- Please describe more detail the participants (see General Comments).
- Statistical Analysis. Please add that data were mean ± SD.
- Discussion
Please describe more detail the limitations of this study at the end of Discussion (see General Comments).
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
