Reliability of a Field-Based Test for Hamstrings and Quadriceps Strength Assessment in Football Players

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