Studio pilota su ¿stop and go¿ attesi e inattesi in una popolazione di atleti, attraverso l'utilizzo di un nuovo dispositivo indossabile che integra IMU e EMG.

Background. In latest years a growing interest in training load measurement is recognized both in the scientists and practitioners community. Furthermore, a large amount of devices and methods have been developed in order to help coaches and medical teams during the training process, also in a preventive way. Yet, different features expose the soccer player to a high injury risk. High physical efforts, unexpected conditions and fatigue are thought to be some risk factors particularly for knee injury. The aim of the current study were (1) to test a new wearable device integrating IMU and EMG (Remo, Morecognition, Turin, Italy) in a sport setting, (2) to detect the biometrical and neuromuscular differences between pre-planned (PP) and UN condition while performing the one-leg stop and go task, (3) in pre and post fatigue induction. Methods. 12 male youth soccer players (16 y, 176,2 ± 5,8 cm, 64,2 ±6,5 kg) were randomly assigned to PP or UN group. The experimental protocol consist of a circuit in wich different running velocities and the OLSG (5m sprint- OLSG- 5m sprint- 12.5m active recovery- 15m sprint- 12.5m active recovery) were performed until exhaustion. In UN condition the athlete made the stop in response to a visual stimulus. For the data analysis the HR trend, the time till exhaustion (TTE), the number of laps (n°L), the RPE (every 3 laps on the circuit), the myoelectric trace of 4 upper leg compartments (anterior, posterior, lateral, medial) and the global IMU information through the entire protocol were recorded, in each condition. Results. HR trend show no significant difference between condition, even though UN shown a higher SD between the measurements. On average, in PP the TTE and n°L were higher when compared to UN, meaning in an earlier maximal exertion achievement in the second condition. Thanks to the IMU and EMG device it has been possible to reconstruct the running path of the athlete on the testing protocol. PP shown no differences between pre (first rep) to post (last rep) fatigue in muscular activation. On the contrary in UN a tendency to decrease the EMG activity was found. This effect was appreciable also in A/P ratio. Discussion and conclusion. These findings suggest that UN and fatigue, which are conditions close to real game situation, could expose the knee to high injury risk. Therefore, a neuromuscular training, even after fatigue induction, could be consider in a preventive protocol. In conclusion, we can affirm that our EMG and IMU wearable device really helps us in the evaluation, even though the validation protocol are going to be run in the following months.