# Applied Biomechanics in Sports Performance, Injury Prevention, and Rehabilitation
## 2 An Overview of the Published Articles  
Biomechanical analysis plays a crucial role in understanding and optimizing sports performance. This Special Issue compiles research addressing various aspects of the application of biomechanics to sports, covering topics ranging from movement variability in skiers to the integration of concurrent training into the development of swimmers and young soccer players. In the study on slalom skiing, [PERSON] et al. (contribution 6) assessed how slope steepness and gate configurations influence movement variability (MV) and performance in elite skiers. By measuring MV through entropy and by analyzing total race time, the researchers found that steeper slopes and curved courses significantly increased MV, while better race times were correlated with lower MV. These findings underscore the role of motor control in technical skiing performance. On the other hand, [PERSON] et al. (contribution 8) explored the effects of a concurrent training program combining maximum strength or muscular endurance with sprint interval training (SIT) in swimming. After six weeks, improvements in stroke rate (SR) were observed in groups incorporating dryland training, while no significant changes were noted in stroke length or stroke index. These findings suggest that concurrent training can enhance specific biomechanical components, particularly stroke rate, improving efficiency in front crawl swimming. In their study on the interaction between strength training and running performance, [PERSON] et al. (contribution 9) compared velocity-based training (VBT) squat protocols to evaluate their acute effect on the maximal aerobic speed (MAS). All protocols reduced MAS compared to the control condition, with the greatest decrease observed with higher velocity loss during sets. These results indicate that the immediate application of VBT before endurance tests can negatively affect aerobic performance due to the induction of fatigue. [PERSON] et al. (contribution 12) examined the impact of a combined balance and multidirectional pylemetric training program in U-13 soccer players. Although no significant changes in postural stability were recorded after six weeks, a trend towards improvement was identified with regard to lower-limb explosive performance. However, visual restrictions impaired postural control, highlighting the importance of evaluating challenging conditions during training. Two recent studies addressing biomechanical aspects related to muscle activation and isometric strength assessment offer new insights with utility in rehabilitation and training. In the first study, [PERSON] et al. (contribution 2) investigated antagonist muscle coactivation in thighs and ankles during the sit-to-stand task in post-stroke and healthy subjects. Dysfunctional coactivation was more pronounced in ankle muscles than in thigh muscles, suggesting that the distal segment may better reflect central nervous system dysfunction in post-stroke patients. These findings highlight the importance of conducting further studies to clarify the spatiotemporal variability in coactivation levels in this population. In the second study, [PERSON] et al. (contribution 5) assessed the between-session reliability and concurrent validity of using the FysioMeter H-station to measure isometric quadriceps, hamstring strength, and the hamstring-to-quadriceps (H/Q) ratio compared to the values obtained with an isokinetic dynamometer (ID). The H-station demonstrated excellent relative reliability and moderate to strong concurrent validity for hamstring and quadriceps strength compared to the ID. These results indicate that the H-station is a reliable tool for tracking relative changes in isometric strength, providing a practical alternative to the ID for clinical and sports environments. Biomechanics is also a crucial discipline in terms of understanding how athletes perform and how they can reduce the risk of injuries.