###### Abstract
From the ground reaction forces measured, jump height can be estimated using different parameters: flight-time, impulse-momentum, and work-energy. Flight-time is determined from the contactless interval with the FP [7]. The impulse-momentum and work-energy methods both permit the calculation of the instantaneous take-off velocity, where jump height is calculated from the equations of motion of a projectile [7]. The author found that flight-time is the most accurate, and the work-energy method is the least accurate. For better accuracy when using the impulse-momentum method, a positive displacement must be added to account for the contribution of ankle extension in the final period before take-off [10; 11]. [PERSON] [10] compared the results from double integration of vertical ground reaction force, time in the air, and take-off velocity methods and found that take-off velocity, obtained from impulse-momentum, led to more reliable results when a positive displacement was added. [PERSON] et al. [6] validated jump height measurements obtained with FP's and Vertec (height reaching/marking) devices by comparison with a motion capture system. [PERSON] et al. [14] found that applying flight-time and double integration methods to the FP measurements leads to systematic errors. A high degree of linearity existed when compared with the video-based measurement method. The study revealed better results for the double integration than for the flight-time method considering both the validity and reliability of the jump height calculation. The search for simple and accurate ways to assess jump height in field-testing means new technologies continue to emerge, although typically employing only a few simple mechanical principles. Switch-mat tests were introduced [15], with the Ergojump (EJ) device widely used for vertical jump measurement [16; 17]. Their main advantage compared to laboratory devices is that they do not require extensive preparation or analysis time and are simple to operate. Furthermore, this allows for a large volume of participants to be measured in a small period of time. The jump mat approach uses flight-time (the duration without contact between participant and mat) and kinematic equations of uniform acceleration to assess jump height. [PERSON] [18] questioned the validity of jump height measurementscalculated from flight-time since the jump height could be artificially increased due to the athlete's joint configuration at landing, which without clear instruction is typically more flexed to attenuate impact forces at landing. In addition, ankle extension during the two jump phases underestimates the maximum height attained during the jump [19; 20]. The accuracy of flight-time given by a jump mat was analysed by comparing it with the FP, and it was found that flight-time was consistently larger for the jump mat than for FP [19]. More recently, a new generation of technologies has gained wide-reaching use. Accelerometers are increasingly used for assessing human movement [21]. Using an accelerometer (MP) device, the vertical acceleration is measured during the jump and is integrated over time to determine the vertical velocity. Jump height is derived from flight time, which is determined by considering the time interval between maximum and minimum vertical velocities. Due to small differences between MP and FP measurements, MP has been proposed to be a valid tool to assess jump height [20], although other studies have identified an overestimation of the jump height from this type of device [8]. Jump height validity, based on flight-time obtained through MP and Optojump systems, was also assessed concerning the FP measurements [22], concluding that both systems can be accurately used for field-based measurements. [PERSON] et al. [22] analysed the validity and reliability of MP measurements, obtained with flight-time and an alternative approach of using the vertical take-off velocity to calculate jump height. They concluded that a flight-time method was reliable for field-based jump assessment.