engleski

THE INFLUENCE OF FATIGUE ON KINEMATIC PARAMETERS OF BASKETBALL FUNDAMENTAL SKILLS – PASSING, SHOOTING AND DRIBBLING

Purpose: The main aim of this doctoral thesis was to determine the influence of fatigue on kinematic parameters in basketball fundamental skills. Within this doctoral thesis, five independent studies (Study 1-passing, Study 2, Study 3, and Study 4-shooting, Study 5-dribbling) were investigated. Study 1 set out to exam the influence of fatigue on kinematic parameters and accuracy in basketball passing. Study 2 aimed to assess the influence of fatigue on kinematic parameters and accuracy in female basketball shooting. Study 3 set out to determine the influence of progressive physiological load on kinematic parameters and accuracy in young male basketball shooting. Study 4 aimed to compare the kinematic parameters of 2-point and 3-point jump shots and ascertain the differences between elite male under 16 and 18 and female under 16 and 18 basketball players. Study 5 set out to investigate the influence of fatigue on kinematic parameters and the speed in basketball dribbling. Methods: In study 1, Eleven Croatian basketball players who are members of the youth national program (age: 18.36 ± 0.67 years ; height: 192.32 ± 9.98 cm ; weight: 83.35 ± 11.19 kg ; body fat: 15.00 ± 4.40%, arm span: 194.34 ± 10.39 cm) participated in the study. 3D motion analysis using inertial sensor technology (Xsens suit) was used to analyze the kinematic parameters of push passing ; a radar gun was used to determine ball speed ; heart rate and blood lactate concentration were used to identify fatigue and non-fatigue condition. In study 2, thirty-two professional female basketball players volunteered to take part in the study (age: 22.11 ± 4.92 years ; height: 173.99 ± 7.06 cm ; weight: 67.89 ± 5.65 kg). The Xsens suit and smart ball were used for measuring the kinematic parameters. A shooting machine was used to standardize each pass, directly influencing the shooting efficiency, and to minimize the interference from external factors. To monitor the fatigue level, the blood lactate concentration and rating of perceived exertion were conducted during the testing. In study 3, one player (age: 17.36 years) who is a member of the Croatian U18 Men’s National Team was evaluated as a case study. To measure kinematic parameters during the jump shot, the SIMI Motion system with eight cameras and a smart ball were used. The progressive physiological loads were determined by blood lactate concentration. Forty-eight young male and female basketball players participated in study 4. To assess the kinematic parameters of 2-point and 3-point shooting, Xsens suit was used with the addition of a smart ball. In study 5, fourteen Croatian senior basketball players excluding power forwards and centers (age: 21.16 ± 3.43 years ; height: 188.81 ± 6.88 cm ; weight: 87.81 ± 6.06 kg ; body fat: 13.34 ± 3.52 %) participated in the study. Each player performed two types of change of direction with dribbling: front change of direction and spin move. Xsens suit and Novel pressure insoles were used to measure the kinematic and kinetic parameters respectively. Heart rate and blood lactate concentration were employed to monitor players’ fatigue level. Results: In study 1, there was significant difference in angular velocities of shoulder (p = 0.01), elbow (p = 0.04), and wrist (p = 0.01), ball speed (p = 0.00), pelvis position (p = 0.00), and velocity of the pelvis in X-axis (p = 0.00) between fatigue and non-fatigue condition. Additionally, the passing accuracy significantly decreased when players were under the influence of fatigue (p = 0.01). In study 2, the results demonstrated that there were no significant differences in angular velocities of ankle, knee, and hip joints between fatigue and non-fatigue condition. Conversely, differences in angular velocities of elbow (p = 0.036) and wrist (p = 0.002) were detected. Furthermore, the results showed that the release height and entry angle of the ball significantly decreased under the influence of fatigue. Moreover, the shooting accuracy did not noticeably decrease when players were under the influence of fatigue. In study 3, the obtained results indicated certain differences in angular velocities of the upper and lower extremities regarding different fatigue levels, as well as in the height at the moment of releasing the ball under the influence of progressive fatigue. In study 4, players in male categories shot for 2-point with a higher center of mass difference in the vertical direction, with higher release shoulder angle, and with a higher entry angle of the ball when compared to female categories (p < 0.001). In the 3-point shooting, there were differences between male and female categories in the shoulder angle when releasing the ball (p < 0.001). In the players’ shooting speed, there were differences between U16 male vs U18 female and U16 female vs U18 female (p = 0.02) players. Male categories shot 3-point shots with a smaller center of mass difference in the horizontal direction when compared to 2-point shots (p < 0.001). The entry angle was higher in successful shooting attempts compared to unsuccessful shooting attempts when shooting for 3-point (p = 0.02). Player shooting speed was higher in all categories (except U18 female) when shooting for 3-point (p < 0.001). In study 5, in terms of the front change of direction, the results demonstrated that the maximum angular velocities in knee joint (p=0.028), wrist joint (p=0.007), and maximum force (p=0.004) significantly decreased under the influence of fatigue ; the pelvis position and minimum angle in knee joint were higher under the influence of fatigue compared to the non-fatigue condition, but there was no significant difference. In terms of the spin move, the results showed that there were significant differences in pelvis velocity (p=0.000), maximum angular velocity in knee joint (p=0.020), and first step velocity (p=0.010) ; however, no significant difference was detected in the pelvis position, minimum angle in the knee joint and maximum force. Importantly, the dribbling speed significantly decreased in the fatigue condition (p=0.002). Conclusions: In general, fatigue has negative influence on kinematic parameters and players performance in basketball fundamental skills. To be specific, (1) The major conclusion drawn from study 1 showed that fatigue affects the kinematic parameters and accuracy in basketball passing. The findings of this study suggest that players need to adopt the correct motor structure of passing to create an automatism during the training process of learning. Additionally, coaches need to conduct as many drills as possible in situational conditions that are similar to the conditions during the basketball game. As a result, the players’ passing performance will ultimately not change even under the influence of fatigue. (2) The results of study 2 indicated that elite female basketball players can maintain the efficiency through readjusting the neuromuscular system to make a successful jump shot when they were under the influence of fatigue. Furthermore, the results of current study showed that the release height and entry angle of the ball significantly decreased under the influence of fatigue, suggesting that coaches need to include in the training process exercises that are similar in terms of fatigue and performance to the situational conditions during the game as these two variables play an important role in determination of the shooting accuracy. (3) The major conclusion drawn from study 3 was that fatigue impacts certain changes in the kinematic parameters of the jump shot in terms of young male players. The angular velocities of joints in the lower extremities noticeably increased, while the mentioned parameters in the upper extremities decreased when physiological load increased. Additionally, the height of releasing the ball decreased. Despite the changes in the above- mentioned parameters, the action performed on the ball remained unchanged, considering that the shooting speed, as well as the angle at which the ball entered the basket, demonstrated no changes. Even though the action performed on the ball did not alter from the biomechanical standpoint, the reduction of shooting accuracy under the influence of a higher level of fatigue still suggests that certain deviations occurred in the overall pattern of performing the examined motor skill. Therefore, coaches are required to design appropriate training sessions to resist the influence of fatigue on jump shot performance. (4) The results of study 4 showed that female and male basketball players used different shooting techniques. Additionally, players in male categories shot with a higher center of mass difference in the vertical direction, with a higher release shoulder angle, and with a higher entry angle of the ball. Moreover, the entry angle of the ball increases in all categories when shooting for 3-point, which means that players need more time for 3-point shots after receiving a pass when compared to 2- point shots. Therefore, the players are using excessive movements to optimize the shooting technique when shooting for 3-point. Basketball coaches and players should work to minimize the kinematic differences between 2-point and 3-point shots to increase the successfulness of shooting from longer distances. (5) The major conclusion drawn from study 5 is that fatigue affects the kinematics and kinetics of basketball dribbling. Additionally, the dribbling speed significantly decreased when the players were under the influence of fatigue. From the result point of view, the higher pelvis position, the lower angular velocity in knee and wrist joint, and the lower force when the players are under the influence of fatigue may induce that they are not able to take advantage of the defender successfully. Additionally, the decrease of the dribbling speed under the influence of fatigue will cause the players’ inability to pass by the defender quickly during the fast break and transition period, which consequently makes them lose the opportunity of scoring. Therefore, the findings of this study suggest that coaching staff is required to design appropriate training sessions to optimize players’ ability to resist fatigue when dribbling in real game speed conditions.

accuracy, efficiency, angular velocity, pelvis velocity, ball speed, female basketball, youth basketball, kinematic analysis, kinetic analysis, Xsens, change of direction, spin move, joint angle, center of mass, pass, jump shot, dribble

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