Damir Knjaz

Prof. Dr. Damir Knjaz

Faculty of Kinesiology, University of Zagreb

Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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PŠPeter Šagát
Peter Šagát
Peter BartikPeter Bartik
Peter Bartik
ALAnja Lazić
Anja Lazić
DTDragos Ioan Tohanean
Dragos Ioan Tohanean
VKVasilios Koronas
Vasilios Koronas
ICIoana Maria Curitianu
Ioana Maria Curitianu
On the basis of the integrative concept of self-esteem discussed in sport-related literature, various studies refer to its importance in the context of sports activities. Self-esteem is often understood as a personality trait because it tends to be durable and stable. No accurate description is available regarding the types of sports in which subjects participated. The main purpose of the research was to identify and compare the levels of self-esteem and self-confidence of athletes practicing individual and team sports. The self-esteem and self-confidence levels were measured by the Rosenberg Self-Esteem Scale (Rosenberg 1979) and the Self-Confidence Test (Romek, 2000). All participants were males. Subjects were divided into two categories: 40 for individual sports and 40 for team sports. There were two evaluation periods: P1, the beginning of the preparation period, and P2, the beginning of the competition period. There were statistically significant differences for P1 (p < 0.002) and P2 (p < 0.003). The differences between the average values of the two periods were 5.8 points and 3.8 points, both favorable to the group of athletes who practiced individual sports. There were significant differences between the individual and team athletes in self-esteem level. Individual athletes presented a higher level of self-esteem.

Tomáš VencúrikTomáš Vencúrik
Tomáš Vencúrik
JNJiří Nykodým
Jiří Nykodým
DBDominik Bokůvka
Dominik Bokůvka
TRTOMISLAV Rupčić
TOMISLAV Rupčić
Damir KnjazDamir Knjaz
Damir Knjaz
ISIvan Struhár
Ivan Struhár
This work aimed to identify the influence of selected endogenous (internal load) and exogenous (possession duration, game quarter, and defensive pressure) factors in natural game conditions on the efficiency of dribbling and passing skills. Dribbling and passing skills were assessed during four games of U19 female basketball players and five games of senior (2nd division) female basketball players. In total, 551 dribbling and 914 passing executions were evaluated. Binary logistic regression identified defensive pressure of the opponent as a predictor of dribbling and passing skills effectivity. When the defensive pressure of the opponent was medium, the chances for the ineffective pass were 1.997 times more likely (95% CI; 1.179–3.383), as it is at the minimum defensive pressure. When the defensive pressure of the opponent was high, the chances for ineffective dribbling were 7.45 times more likely (95% CI; 3.672–15.113) and for ineffective pass were 8.419 times more likely (95% CI; 4.6–15.409), as it is at minimum defensive pressure. The game quarter and the internal load were not identified as the predictors influencing the dribbling and passing effectivity. Possession duration was also an insignificant predictor of dribbling and passing skills effectivity. However, the passing skill effectivity decreases when the shot clock is winding down. These findings confirm the importance of transferring game situations into the training process. Coaches should take into account these factors when they want to stimulate determinants of player performance in a balanced and systematic way.

Tomáš VencúrikTomáš Vencúrik
Tomáš Vencúrik
Damir KnjazDamir Knjaz
Damir Knjaz
TRTOMISLAV Rupčić
TOMISLAV Rupčić
Goran SporišGoran Sporiš
Goran Sporiš
Feng LiFeng Li
Feng Li
Basketball shooting is one of the most important offensive skills in basketball. Winning or losing a game mostly depends on the shooting effectiveness. The study aims to compare the selected kinematic variables of 2-point (2-pt) and 3-point (3-pt) jump shots (after making a cut and receiving the ball) and ascertain the differences between elite male under 16 and 18 (U16M, U18M) and female under 16 and 18 (U16F, U18F) basketball players. Overall, forty-eight young male and female basketball players participated in the study. 3D motion analysis using an inertial suit with the addition of utilizing a smart ball was performed for assessing the 2-pt and 3-pt shooting techniques. Players in male categories shot for 2-pt with a higher center of mass difference in the vertical direction (U16M 5.7 cm, U18M 3.9 cm vs. U16F 1.4 cm, U18F 0.6 cm), with higher release shoulder angle (U16M 110.9, U18M 113.8 vs. U16F 103, U18F 105), and with a higher entry angle of the ball (U16M 34, U18M 32 vs. U16F 30, U18F 30) when compared to female categories (p < 0.001). In the 3-pt 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 U16M vs. U18F (0.95 ± 0.1 vs. 0.88 ± 0.1; p = 0.03) and U16F vs. U18F (0.96 ± 0.06 vs. 0.88 ± 0.1; p = 0.02) players. Male categories shot 3-pt shots with a smaller center of mass difference in the horizontal direction when compared to 2-pt shots (p < 0.001). The entry angle was higher in successful shooting attempts compared to unsuccessful shooting attempts when shooting for 3-pt (p = 0.02). Player shooting speed was higher in all categories (except U18F) when shooting for 3-pt (p < 0.001). It appears that performers show difference in kinematic variables based on distance from the basket. Basketball coaches and players should work to minimize the kinematic differences between 2-pt and 3-pt shooting and to optimize the shooting technique.

1 January 2021 in Kinesiology
Verified
Journal Article
Closed access
PDF file
Feng LiFeng Li
Feng Li
TRTOMISLAV Rupčić
TOMISLAV Rupčić
Damir KnjazDamir Knjaz
Damir Knjaz
Basketball dribbling is one of the key elements in basketball game. There is a lack of studies investigating the effect of fatigue on kinematics and kinetics in basketball dribbling. There are two primary aims of this study: (1) to explore the effect of fatigue on kinematics and kinetics in dribbling with the change of directions; (2) to determine the effect of fatigue on dribbling speed. Fourteen Croatian senior male basketball players, not power forwards or centers (age: 21.16±3.43 years; body height: 188.81±6.88 cm; body mass: 87.81±6.06 kg; body fat: 13.34±3.52%) participated in the study. Each player performed two types of change of direction (COD) while dribbling: front COD and spin move in the non-fatigued and then in the fatigued state. Xsens suit and Novel insoles were used to measure the kinematic and kinetic parameters. In terms of the front COD, the results of this study demonstrated that the maximum angular velocity in the knee (p=.028) and wrist joint (p=.007) as well as maximum force (p=.004) significantly decreased in the fatigued state. In terms of the spin move, the results showed that there were significant differences in pelvis velocity (p=.000), the maximum angular velocity in the knee joint (p=.020), and the first step velocity (p=0.010) between the fatigued and non-fatigued states. No significant difference was found in the pelvis position, minimum angle in the knee joint and maximum force. Importantly, dribbling speed significantly decreased in the fatigued state (p=.002). The findings of this study suggest that coaching staff should design appropriate training programs to optimize players’ ability to resist fatigue when dribbling under real game speed conditions.

IBIvan Bon
Ivan Bon
MOMateja Očić
Mateja Očić
VCVjekoslav Cigrovski
Vjekoslav Cigrovski
TRTOMISLAV Rupčić
TOMISLAV Rupčić
Damir KnjazDamir Knjaz
Damir Knjaz
There are numerous programs worldwide adapted for alpine ski beginners and they all share the same primary goal—inclusion of skiing beginners in alpine ski schools. The final elements of ski school taught in the parallel skiing technique are parallel turn and short turn. Synchronized analysis of kinetic and kinematic parameters of the parallel turn (PT) and short turn (ST) was conducted to determine the main biomechanical differences from a standpoint of foot pressure and lower limb angles. Both elements were performed by nine male ski instructors (age 33.4 ± 8.62, height 179.52 ± 5.98 cm, weight 78.6 ± 8.88 kg). Kinetic and kinematic analysis was conducted on 180 turns, 90 for each element. Differences in kinetic and kinematic parameters between parallel and short turns were tested by a paired t-test. The main findings of our study are determined differences in the ratio of pressure distribution on the inside and the outside foot and differences in kinematic parameters of the outside leg between elements. The mentioned analysis can provide an objective insight into the complexity of each element and provide guidelines for teaching process of those elements. This study determined the reasons for higher complexity of ST compared to PT based on the objective evaluation of biomechanical factors.

21 October 2024 in Applied Sciences
Verified
Journal Article
Open access
PDF file
Feng LiFeng Li
Feng Li
VDVedran Dukarić
Vedran Dukarić
MOMateja Očić
Mateja Očić
ZLZheng Li
Zheng Li
Damir KnjazDamir Knjaz
Damir Knjaz
This study examines the influence of fatigue and defensive pressure on the kinematic parameters of the three-point jump shot in basketball. Fourteen male collegiate basketball players (age: 21 ± 3 years old, body height: 186.35 ± 7.02 cm, body mass: 82.20 ± 10.99) participated in the study. Each participant performed three-point jump shots under four conditions: without defense, with defense, without defense after a fatigue protocol, and with defense after a fatigue protocol. Kinematic data were collected using the Xsens MVN inertial suit system and the OptoJump Next system. The analysis focused on various parameters including jump height, center of mass, release height, shoulder angle, and segment velocities. The repeated-measures ANOVA was used to observe the differences between each shot condition (fatigue, defense). Results indicated significant changes in the kinematic parameters due to both fatigue and defensive pressure. Fatigue notably changed shooting performance, affecting jump height and release mechanics. The defensive pressure altered shooting technique, leading to quicker ball release and higher release points. These findings highlight the importance of incorporating fatigue and defensive scenarios in training, suggesting that coaches develop more targeted training plans to improve performance under conditions of fatigue and defensive pressure.