## 1 Introduction  
Strength assessment is of critical importance in sports medicine during the injury management and return-to-play process. Identifying inadequate strength levels or muscle imbalance may assist in reducing the injury risk [1; 2]. In addition, strength measurements are widely advocated for assessing injury severity and prognosis, and as an effective assessment for controlling injury rehabilitation success [3; 4]. Specifically, strength imbalance between knee flexor (hamstring) and extensor (quadriceps) muscles has been suggested as a risk factor marker for an acute hamstring injury and re-injury [5; 6; 7]. Furthermore, a recent review pointed out that lower limb injuries, such as anterior cruciate ligament tears, can occur when hamstrings are limited to produce force enough for the slow rotation or high shear of the anterior tibia in the extended movements of the knee, which are induced by the maximum strength of the quadriceps [8]. It is well-known that isokinetic dynamometers are the gold standard for strength assessments in clinical settings; however, they are expensive and difficult to transport, which limits their use in the field. On the other hand, at present, one can easily and automatically collect force metrics while providing real-time visual feedback using force plates or portable force sensors attached to a bench, a post or a table [9; 10; 11]. This opens a window to provide physicians and coaches with more practical and user-friendly tools for strength assessment and injury risk screening. Muscle strength in the lower limb is commonly tested through the maximum voluntary isometric contraction (MVIC) as the highest force the individual can produce during an isometric test [12; 13]. MVIC is a reliable variable during isometric knee flexion and extension tests using hand-held dynamometers [14; 15] and fixed force sensors [16; 17; 18]. However, whereas MVIC can be useful to determine the force production in the late phase of the muscle contraction (300 ms after the contraction onset), it seems limited to check the players' ability to produce force immediately after the contraction onset (0 to 200 ms) [12; 19]. An alternative to the MVIC, the rate of force development (RFD) emerged as a more accurate measure to screen the force production at rapid events, which may describe better players' performance during football match-specific movements [20]. Importantly, RFD measurements taken with the knee near full extension (\(\sim\)30\({}^{\circ}\) of knee flexion) can provide important information about the recruitment of the posterior chain muscles [21] which is related to the anterior cruciate ligament and hamstring strain injury mechanism [22; 23]. RFD has an important neural component, as it requires the player to perform ballistic actions as fast and strongly as possible; therefore, robust procedures need to be employed to achieve sufficient reliability [20; 24]. Previous studies have examined RFD metrics with different equipment during isometric knee extension [16; 25] and flexion [26]. However, there is still no data available about RFD reliability at nearly extended knee positions. This is important given the aforementioned potential relationship with the injury mechanism. Another metric of interest to monitor muscle imbalances and knee joint stability [8] is the hamstring-to-quadriceps muscle strength ratio (H:Q). Previous findings suggested that deficits in the H:Q strength ratio may increase the risk of hamstring strain injury in football players [27]. The H:Q ratio has shown high reliability for RFD and MVIC in elite football players using sophisticated equipment such as an isokinetic dynamometer [28]. However, to the best of our knowledge, no study has analysed hamstring and quadriceps force production and H:Q ratio in a near-extended knee position with a field-based test. The existence of a reliable field test to measure these variables may be key to avoiding the cost and limitations of laboratory-based measurements (e.g., isokinetic dynamometer).