## 4 Discussion
These biases exceed the Standard Error of Measurement (SEM) of the ad hoc Excel/VBA spreadsheet, whether using take-off velocity or flight time to estimate jump height. The MCD\({}_{90}\) and MCD\({}_{95}\) confirm that the spreadsheet is capable of detecting most of the changes discussed, as it can detect changes in jump height of 1.28 or 1.52 cm and 0.16 or 0.19 cm when using the take-off velocity or the flight time, respectively. Regarding propulsive impulse, fewer studies have focused on this variable, possibly due to the relative ease and interpretability of measuring jump height. Since the MARS 4.0 software does not provide a propulsive impulse measurement directly, the force impulse from maximal force to take-off was used as an approximation. Given that propulsive impulse directly determines take-off velocity and consequently flight height, it is arguably a more direct and potentially less error-prone variable than flight time [34]. An observational study reported propulsive-concentric impulses of 171.18 \(\pm\) 38.6 N \(\cdot\) s in females and 254.1 \(\pm\) 37.46 N \(\cdot\) s in males [35], so the ad hoc Excel/VBA spreadsheet could detect these differences, because it showed a margin of error of 5 N \(\cdot\) s. In other related research, the platform recorded concentric impulse values of approximately 230 \(\pm\) 50 N \(\cdot\) s in CMJs [16]. This standard deviation (50 N \(\cdot\) s), encompassing both random and systematic errors, is significantly higher than the Excel/VBA spreadsheet's 5 N \(\cdot\) s error, indicating that this can be considered a minimal error. Furthermore, the use of arm swing on concentric impulse allows for a gain in propulsive impulse of about 30 N \(\cdot\) s [15], a difference also detectable by the Excel/VBA spreadsheet. In this case, the MDC\({}_{90}\) and the MDC\({}_{95}\) indicated that a change greater than 4.55 or 5.41 N \(\cdot\) s would be required to be certain that the change is not due to measurement error when using the spreadsheet. These values are also below the differences in the means of the studies used as examples, confirming the sensitivity of the measurement. The present study was not exempt from limitations. Firstly, this study's focus on young, healthy male participants limits its applicability to other groups. Although the Bland-Altman plots did not show any kind of tendency on the residuals, it would be necessary to study whether the template is still accurate with lower jump heights, achieved, for example, by children or sedentary people or even with athletic jumpers reaching greater jump heights. Although no statistical power study was conducted, the sample size was similar to that of studies analysing jumping assessment instruments or procedures [8; 25; 26; 28]. In addition, the events are marked based on visual observation of the signal and there exists a human error that has to be considered. Manual marking of CMJ phases could introduce subjectivity and inconsistencies, particularly for inexperienced users. Such error can be assessed by comparing the marking of events with a fully automatic system and also by performing intra- and inter-rater reliability studies. Nevertheless, the sheet includes calculations that attempt to minimize such error. In particular, three subtractions of force impulses are calculated which should be the closest possible to zero, explained at the end of the Section 2.2.1. On the other hand, considering its wide use in research, only one brand and one force platform software (Kistler and MARS 4.0) was used, and it would be interesting to analyse whether other systems could provide similar accurate results. Finally, a fourth-order, zero-phase-shift Butterworth low-pass filter was selected, based on a previous study [28], but perhaps other types of filters would have been more appropriate (e.g., an adaptive filter [23] or a residual-based filter). Despite these limitations a notable advantage of the custom Excel/VBA spreadsheet is its adaptability and ease of use.