# Comparison of Countermovement and Preferred-Style Jump Biomechanics in Male Basketball Players
## 4 Discussion
This interpretation is consistent with previous studies that found inadequate evidence about correlations between jump performance of soccer- or basketball-specific jumping tasks and the CMJ [15; 16; 17]. These findings may have practical implications for settings where the CMJ is used as a measure of neuromuscular performance or readiness in basketball players [23] and suggest that the ecological validity of the CMJ in the context of assessing and monitoring neuromuscular performance of these athletes should be critically examined and further scrutinized in future studies. Another primary finding of the current study was that the Pref] was characterized by greater magnitudes of several joint-level kinetic parameters. More specifically, the Pref] exhibited much larger peak extension NJM and positive NJP magnitudes than the CMJ, regardless of whether the comparison involved the lead of trail leg during the Pref]. Since NJM during jumping tasks are largely created by muscles that produce moments of force at a specific joint, peak NJM values are often used to obtain insight about the mechanical demands that are imposed at the respective joint [14]. Although, the ability to generate NJM during any task are subject to constraints imposed by the moment-angle-velocity relationships [24], joint kinematic differences between the CMJ and Pref] were not as prominent or consistent as joint kinetic differences. Notably, some of the kinematic differences varied across the respective legs during Pref], which appeared to be the result of its asymmetric movement pattern [18]. Specifically, hip and knee peak flexion angles of the lead leg during the Pref] were greater than during the CMJ, whereas peak ankle dorsiflexion of the trail leg was smaller. In contrast, peak hip extension velocity of the trail leg during the Pref] was smaller than during the CMJ, but peak knee extension velocity was greater. It is therefore difficult to ascribe the differences in joint kinetic to differences in joint kinematics. The discrepancy between CMJ and Pref] peak joint kinetics may suggest that the NJM magnitudes during the CMJ do not reflect the maximal absolute moment-generating capacity of the extensor muscle groups during dynamic jumping tasks. In addition, the differences in positive and negative NJW would indicate that the athletes used distinctly different movement strategies during the two types of jumps [4; 11]. The general lack of correlations between positive and negative NJW during the Pref] and CMJ supports this conclusion. The jump-dependent difference in movement strategy may help partially explain the smaller NJM and associated lower GRF, COM velocities, and jump heights observed during the CMJ [14], especially if one considers that the task constraints of the CMJ prevent an athlete from using their preferred coordination pattern. The only study to have investigated joint-level differences between a sport-specific jump (i.e., volleyball spike jump) and the CMJ found that the jump heights of both types of jumps were correlated with each other [18]. Although, the authors suggested that this correlation demonstrated that performance of the sport-specific jump is influenced by general jumping ability, they did not investigate correlations between any of the kinematic variables nor did they investigate any kinetic variables. It is therefore not clear if the reported correlation extends beyond general jump performance and to joint-level biomechanics. Like the results and interpretations of the whole-body biomechanical data of the current study, the joint-level biomechanical data suggest that kinematic and kinetic data from the CMJ may only provide limited information with respect to either maximal absolute neuromuscular capacity or movement strategies, which again may have practical implications for using the CMJ as a basketball-specific assessment or monitoring tool in the applied setting. The results of the current study should be interpreted in light several limitations.