Neuromuscular Performance Thresholds to Support Player Development in a Professional Soccer Academy

Purpose: We aimed to compare neuromuscular performance between academy soccer players (U-17, U-19, and U-21 categories) and first-team players, and to establish neuromuscular performance thresholds associated with the first-team level. Methods: Ninety-four male players participated and were followed over two seasons. Neuromuscular performance was assessed using force-plate and force-sensing frame technologies, including isometric hip adduction and abduction, Nordic hamstring exercise, countermovement jump (CMJ), and isometric squat hold. Peak force, eccentric and concentric peak force, rate of force development, impulse, modified reactive strength index (RSI-modified), dynamic strength index (DSI) and limb asymmetry were analyzed. Linear mixed models, binary logistic generalized estimating equations (GEE), and receiver operating characteristic (ROC) curve analyses were performed. Results: The neuromuscular variables that best discriminated between soccer academy and first-team were maximal hip pull force (OR = 2.53, p < 0.001), concentric peak force (OR = 2.42, p < 0.001), eccentric peak force (OR = 1.31, p = 0.046), modified RSI (OR = 2.00, p < 0.001), RFD at 200 ms (OR = 1.46, p = 0.004), and DSI (OR = 2.13, p < 0.001). ROC analysis identified practical cutoff values for maximal hip abduction force (442 N), maximal concentric and eccentric forces during the CMJ (1856 and 1804 N, respectively), modified RSI (0.58 m·s−1) and DSI (0.57). Conclusions: First-team players demonstrate superior neuromuscular performance to academy players. The identified cutoff values should be considered exploratory benchmarks for distinguishing current competitive levels and require external, prospective validation in independent cohorts from other clubs before practical application.