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Abstract: Miralles-Iborra, A, Del Coso, J, De Los Ríos-Calonge, J, Elvira, JLL, Barbado, D, Urban, T, and Moreno-Pérez, V. Deceleration capacity during directional change as a time-efficient (ecological) prescreening of hip adductor force status in amateur soccer players. J Strength Cond Res 38(12): 2114-2120, 2024-Reduced isometric adductor muscle strength has been identified as a modifiable risk factor contributing to injury in soccer players. However, the measurement of hip adductor muscle strength is habitually laboratory-based, with isolated hip movements that do not reflect soccer-specific movements that induce groin injury during match play. This study aimed to determine the usefulness of deceleration capacity during a change of direction (COD) as a time-efficient (ecological) prescreening of hip adductor force status in soccer players. Nineteen amateur soccer players completed unilateral isometric hip adductor strength assessments and a 180° COD test. Isometric hip strength assessment included the maximum peak torque (PT) and maximum rate of torque development (RTDmax) relative to players' body mass. Players' deceleration capacity during the COD test was determined for each leg through maximum deceleration normalized to the linear momentum. A linear regression analysis was performed to associate isometric hip strength variables with the deceleration capacity during the COD test at each leg. There was not a statistically significant association between deceleration capacity and hip isometric maximum PT of the dominant and nondominant legs ( r ≤ 0.14, p > 0.05). Nevertheless, a moderate association was found between deceleration capacity and RTDmax for both legs ( r ≥ 0.58, p < 0.05). The optimal linear regression model suggests that measuring deceleration capacity during a directional change test could explain RTDmax by 33 and 43% for the dominant and nondominant legs, respectively. During a 180° COD test, the deceleration capacity captured through GPS-accelerometer device was limited as a prescreening tool to evaluate hip adductor force status in soccer players., (Copyright © 2024 National Strength and Conditioning Association.)

Purpose: The purpose of this study was to analyse the relationship between several parameters of neuromuscular performance with dynamic postural control using a Bayesian Network Classifiers (BN) based analysis., Methods: The y-balance test (measure of dynamic postural control), isokinetic (concentric and eccentric) knee flexion and extension strength, isometric hip abduction and adduction strength, lower extremity joint range of motion (ROM) and core stability were assessed in 44 elite male futsal players. A feature selection process was carried out before building a BN (using the Tabu search algorithm) for each leg. The BN models built were used to make belief updating processes to study the individual and concurrent contributions of the selected parameters of neuromuscular performance on dynamic postural control., Results: The BNs generated using the selected features by the algorithms correlation attribute evaluator and chi squared reported the highest evaluation criteria (area under the receiver operating characteristic curve [AUC]) for the dominant (AUC = 0.899) and non-dominant (AUC = 0.879) legs, respectively., Conclusions: The BNs demonstrated that performance achieved in the y-balance test appears to be widely influenced by hip and knee flexion and ankle dorsiflexion ROM measures in the sagittal plane, as well as by measures of static but mainly dynamic core stability in the frontal plane. Therefore, training interventions aimed at improving or maintaining dynamic postural control in elite male futsal players should include, among other things, exercises that produce ROM scores equal or higher than 127° of hip flexion, 132.5° of knee flexion as well as 34° and 30.5° of ankle dorsiflexion with the knee flexed and extended, respectively. Likewise, these training interventions should also include exercises to maintain or improve both the static and dynamic (medial-lateral plane) core stability so that futsal players can achieve medial radial error values lower than 6.69 and 8.79 mm, respectively., Competing Interests: The authors have declared that no competing interests exist.

Featured Application: Knee injuries, such as an anterior cruciate ligament tear, may occur when there are deficits in the hamstring and quadriceps strength as the force production of these muscles is key to maintaining dynamic knee stability during athletic manoeuvres. The current study presents a field-based test with acceptable day-to-day reliability for the assessment of hamstring and quadriceps isometric strength. This tool allows simple field assessments of hamstring and quadriceps strength on a custom-built bench which can be employed to detect muscle deficits during injury prevention and management processes of football teams. Background: Field-based tests using portable devices are extremely helpful to assist physicians and coaches in the assessment of athletes' muscle strength and for injury risk screening. The aim of this study was to investigate the reliability of a field-based test to assess unilateral hamstring and quadriceps isometric muscle strength in a nearly extended position (30° knee flexion) in football players. Methods: Nineteen male football players completed the field-based test on two separate occasions, one week apart, to produce a test–retest design. To complete the test, participants performed maximal isometric efforts on a custom-built bench with 30° of knee flexion and 90° of hip flexion while the force applied was measured with a portable load cell at 80 Hz. On each occasion, participants performed two 2 s maximal isometric repetitions intending to flex and extend the knee to assess hamstring and quadriceps strength, respectively. In each repetition, the force developed during the maximum voluntary isometric contraction (MVIC) and rate of force development (RFD) metrics for hamstring (H) and quadriceps (Q) were collected, and the H:Q ratio was calculated afterwards. Results: MVIC showed the highest reliability for the measurement of both hamstring and quadriceps strength (ICC > 0.80, [95% CI: 0.55, 0.96]; CV < 14%, [95% CI: 6.6, 20]) and for H:Q (ICC > 0.75, [95% CI: 0.48, 0.95]; CV < 15%, [95% CI: 8.9, 22.4]). RFD0–150 and RFD0–250 yielded moderate reliability values for hamstring strength (ICC = 0.78–0.86, [95% CI: 0.52, 0.94]; CV = 20–27%, [95% CI: 15, 39.7]). RFD0–50 presented the largest variability (ICC < 0.80, [95% CI: 0.62, 0.95]; CV > 25%, [95% CI: 19.2, 45.3]). Conclusions: The field-based test presented here provided reliable results for the measurement of maximal isometric hamstring and quadriceps strength and for the calculation of the H:Q ratio. However, the measurement of RFD with this test is less reliable. This test allows reliable field-based assessments of hamstring and quadriceps maximal isometric strength which can be helpful to identify muscle strength deficits and imbalances during injury prevention and management processes in football players. [ABSTRACT FROM AUTHOR]