Optoelectronic systems represent the gold standard of technologies used in the motion analysis for the evaluation of kinematics. Trials, a specialty of mountain biking, differ a lot from other cycling specialties, because in addition to pedaling, they require jumping techniques to overcome obstacles that involve the whole body. In this sport, more than in others, the evaluation of technical movements using optoelectronic systems goes far beyond simply assessing the biomechanics of pedaling or the correct positioning on the bike. Starting from a previous study conducted with video analysis technique applied to the lateral jumping technique, two versions of this technique were compared, considering the kinematics of the act, taking into account both the data relating the subject and the bicycle. The joint angles of the lower limbs and the angles described by the bicycle on the three space plane were considered. The major differences have been found in the "leap over" phase, about the bending of the lower limbs and the angles described by the bicycle.

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This research aims to provide data on explosive and reactive strength characteristics of Italian elite Trials athletes, through vertical jump tests. Five elite athletes (age: 19.6±3.3 y; height: 1.80±0.04 m; body mass: 71.7±7.4 kg) all participating in the Trials World Cup, performed the squat jump and the countermovement jump tests. The height of the jumps was measured using the OptoJump Next (Microgate, Bolzano, Italy). The height of the jump was obtained, then the eccentric utilization ratio (EUR) was calculated as a ratio between the heights of CMJ and SJ, mean and standard deviation of the sample were obtained through a descriptive statistical analysis. Furthermore, a comparison was made between the values obtained and values found in the scientific literature for elite athletes from other sports. From research carried out exclusively data on high-level athletes and performed with OptoJump technology were collected, all studies not corresponding to these criteria were excluded from the analysis. The results show that the Italian elite Trials athletes have good explosive and reactive strength as shown in the SJ (41.0 ± 2.4cm) and in the CMJ (44.0 ± 4.5cm), they also display good performance in comparison to athletes of the same level in other sports, similar to those of hurdlers and volleyball players, also the EUR above 1 (1.07 ± 0.5) suggests that they are well-trained athletes. The results obtained, although on a small sample, provide useful data to describe the athletic profile of Italian elite Trials athletes and could help coaches to structure training programs adapted to the specific demands of this sport.

Aerobic gymnastics is a competitive sport originating from traditional aerobics in which complex, highintensity movement patterns and elements of varying difficulty are performed to music. A fundamental technique in this sport is the Push Up performed with different variations, in an explosive way and as a landing position from a jump. Given the importance of this technique and therefore of the strength of the upper limbs, the aim of this study is to apply the jump tests normally used for the evaluation of the lower limbs to the upper limbs. The study involved two gymnasts (age 16) Gold level of Italian Gymnastics Federation. Three specific tests have been performed: Push Up Jump Test (PUJT); Explosive Push Up Test (EPUT); Free Fall Test (FFT). Two force platforms were used to obtain the vertical component of the ground reaction force (GRF). Peak force (Fmax), rate of force development (RFD), symmetry index (SI), contact time (CT) and flight time (FT) were calculated. This type of analysis can provide useful information on the way in which the force is expressed by the upper limbs, furthermore the comparison between the two limbs can help to identify any asymmetries in pushing or in the management of the impact on landing. It is necessary to carry out further studies on a larger sample aimed at validating this type of test, however the information obtained can be used both to prevent injuries and to monitor and improve performance.

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This study presents the results of quantitative analysis of the karate jump technique. The aim of the study is to investigate the correlation (r) between kinematic and kinetic parameters of the jump from the Unsu Kata. These parameters were identified during the initial phase of the jump (performance indicators), and critical elements were detected during the final phase of the jump (error indicators). The study involved an athlete with the Kata specialty. A six-camera opto-electronic system and two force platforms were used. Statistical correlation was determined between performance indicators and error indicators. The analysis and interpretation of the data reveal that contributions of the forces (ground reaction force and torque) are the most influential parameters on the other variables, which are involved in the evaluation of the jump during its final phase. It appears that the search for the adequate balance between the force components during the takeoff phase, in particular the effects of the forces generated by the torque of the limbs on the body, can be considered as one of the most influential conditions for the success of the jump. The performed analysis of the only participant of the study and the complexity of the technique constitute a starting point for a future study.

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