# Measurement of the Impact Loads to Reduce Injuries in
## 1 Introduction
The landing should be performed to safely reduce all body moment to zero, which can be done with simultaneous placement of both feet on the ground [27]. There are several studies, including reviews, which have found that the landing load induced in gymnastics has a great influence on the possibility of injuries in athletes, in addition to being able to alter gymnasts' performance [28; 29]. The loading platform is one of the most common tools in the analysis of reaction forces during human movement [30]. It is used both for sports performance analysis and for studying the behavior of patients suffering from some pathology, with a focus on health improvement [31]. This device allows the measurement of the action/reaction load exerted on the platform [32], which can help a sports coach to quantitatively evaluate the athlete's performance [33]. The number of repetitions of the exercises and the number of hours of training cause various injuries. To avoid injuries, it is important to identify the forces involved in each jump by trying to replicate the jumps performed in a training session. The need to evaluate the forces induced in the lower limbs during sports has led several researchers to try to develop a force platform adapted to the specific objective [34; 35]. After studying what existed on the market, they did not identify any platform with the required dimensions. Thus, due to the specificity of acrobatic gymnastics, the coaches asked us to develop a platform with dimensions defined by them. Thus, the aim of this study was to build a platform that is a replica of a gymnastics federation-approved practice surface and allows for force values when making the jump. The development of a platform with a similar landing surface is very important because, according to [PERSON] et al. [36], specific injuriescan result from falls and incomplete landing, which may also depend on the type of landing surface. This work uses two load platforms, one commercial, and one specific in-house-built, to measure the vertical landing load of acrobatic gymnasts when landing after a specific jump in acrobatic gymnastics. As is known, landing is a common athletic activity in the practice of gymnastics, which can induce impact forces with a magnitude of 2 to 12 times the body weight, often inducing injuries in the lower limbs. According to [PERSON] et al. [10], the highest percentage of injuries in acrobatic gymnastics occurred in the lower limbs, mainly due to the landing. Thus, it is important to identify the impact forces on athletes during landings in order to define strategies to reduce the probability of occurrence of injuries. Due to the specificity of this sport and the likely landing area of the athletes, it is necessary, for the correct assessment of the forces transmitted to the athletes' lower limbs, to use a force platform that can replicate exactly what happens during training sessions and competitions; thus arose the challenge posed by athletes and coaches for the authors to develop this specific platform. Therefore, the development of a platform that can correctly assess these forces is clearly an asset for athletes and coaches to protect athletes' health. Therefore, the main goal of this study was the development of a load platform that would respond to the needs of gymnasts and coaches by identifying the forces exerted by the lower limbs, together with the way landing was performed. The intention is, by evaluating the landing load values, as well as the type of landing in terms of foot position at the moment of the first contact with the ground, to help athletes and coaches define training strategies to eliminate, or reduce, the risk of injury, specifically, as referred before, in the lower limbs, namely muscle and ligament injuries, as the most frequent.