###### Abstract  
Aims: To determine the intrasession and intersession reliability of the isometric force at three different starting block positions, to compare the intrasession and intersession reliability of the peak and average isometric force of three different starting block positions, and to compare the intrasession and intersession reliability of three different starting block positions. Methods: Eighteen male college students participated in this study. A repeated measures design was used to evaluate the intrasession and intersession reliability of isometric force in three different starting block positions. Results: Very high and extremely high reliability of the average and peak isometric force of the three positions of the starting blocks were obtained, with ICC ranging from 0.63 to 0.91 and a CV close to 10%. Peak force was able to determine the outcomes of the bilateral position with higher reliability than the mean force, and the dominant was the most reliable position for assessing the starting blocks. Conclusion: The functional electromechanical dynamometer can be used with a high level of reliability to assess the force exerted in the starting blocks. athletic performance; reproducibility of results; athletes; muscle strength; resistance training +
Footnote †: journal: Applied sciences  
optimizing the mechanical profile in the application of force and velocity in the propulsion for sprinting [7]. Therefore, monitoring and assessing the force applied under specific conditions is essential [8]. This helps identify the athlete's strengths and weaknesses. Consequently, it allows for better performance prediction in competitions and enables personalized training programs to enhance sporting performance. However, numerous studies in the scientific literature have focused on analyzing measurement devices to predict strength performance in sprimters. These studies typically employ non-specific movements such as countermovement jumps [9; 10] or squat strength assessments [11]. Moreover, a systematic review by [PERSON] et al. [12] demonstrated the transferability of squat strength to sprint performance. Currently, few studies in the scientific literature assess the kinetic parameters of performance during the application of force in a specific cueing gesture. This is because no technology currently exists to assess this particular gesture [13]. The functional electromechanical dynamometer (FEMD) is an innovative tool that addresses this gap. It allows us to quantify, control, and manipulate the training load or manifestations of strength. This can be done directly and immediately, both in average and peak forces, using its different assessment modes [14]. Several authors have contributed to their studies on the reliability of this device by reproducing different sporting gestures [15; 16]. In addition, a previous study determined that the maximum isometric force (MIF) exerted on the starting blocks using FEMD had a very high correlation with performance in the first 5 m of the sprint [13]. Considering that the starting blocks are a sporting gesture with a high horizontal component, performing the most functional assessment of strength possible is necessary. The assessment with FEMD makes it possible to specifically assess the gesture because of the different possibilities it offers for the assessment and development of the strength of a specific movement or sporting gesture, such as the starting blocks [13]. This study addresses a critical gap in the literature regarding the assessment of force application in sport-specific movements, such as the starting block phase in sprinting. Although the force and technique during the start are pivotal for sprint performance, existing technologies have been limited in their ability to accurately and specifically assess this action. By utilizing a FEMD, our study aims to provide reliable data on isometric force across different starting block positions. Ultimately, these advancements may lead to improvements in sprint times and performance assessments.