**1. Introduction**

Handball is an Olympic team sport [1,2], split into two periods (each 30 min long) and consisting of a high degree of body contact and predominantly aerobic activities separated by anaerobic bouts of sprints, jumps, throws, changes of directions in the o ffense (counterattack and attack buildup) and defense [2,3]. Therefore, competition success in elite handball is not only closely related to the technical and tactical skills of each individual or team, but also to the players' anthropometric characteristics, physical performance (e.g., maximal strength and power as measured using strength, sprinting, and jumping tests), and handball shooting performance [3–5].

To date, only a few studies evaluating the physical and physiological demands in handball matches have shown significant di fferences between playing positions [6–8]. Results obtained during gameplay have shown that backcourt players cover larger distances and spend less time standing and walking, and, together with pivots, have higher in-game heart rates and spend longer durations at higher intensities (>80% maximal heart rate) [7]. In contrast, wing players are faster than other playing positions, and pivots endure more body impact than other players [6]. Furthermore, similar di fferences between playing positions were also obtained in anthropometric characteristics [9,10] and physical performance [11–16]. Wings are the shortest, have significantly lower body mass and body mass index (BMI) than other players; pivots are the heaviest, whereas other playing positions do not di ffer in height [9–16]. Research comparing playing positions in sprinting (e.g., sprints on 20–30 m) and jumping performance (squat jump (SJ) and/or countermovement jumps (CMJs)) is relatively scarce, and there are some discrepancies in sprinting times and jump heights among studies [11,14–16]. Nevertheless, backcourt players and wings demonstrated the fastest sprinting times [14,15], while CMJ height was the highest in wings [14], compared to pivots and goalkeepers [15].

Isokinetic dynamometry has long been the gold standard for assessing changes to an athlete's maximal muscle strength/torque during the season [17,18] and risk of injury (measured as imbalances between agonist and antagonist muscles or bilateral di fferences) in di fferent types of a team sport [19]. In the past, only a few studies have evaluated isokinetic maximal knee strength and strength imbalances in male handball players [19–21], with the majority of studies having been performed on female handball players, focusing on shoulder muscle strength, and several on knee muscle strength in relation to shoulder and knee injuries [18,22–25]. Evidence from two studies evaluating isokinetic maximal strength in male handball players has suggested no di fferences between dominant and nondominant lower limb knee extensor and flexor strength, as well as normal hamstring-to-quadriceps ratio on both limbs at 60◦/s and 180◦/s [19,20]. However, no studies in handball have investigated isokinetic maximal strength of the knee joint according to playing position. Furthermore, it also remains to be elucidated the potential role of playing position on development of muscle strength imbalances between and within legs as a product of specific game demands. Such findings would serve as excellent feedback to practitioners to focus on preventing potential injuries and to improve player performance.

Ball velocity has been recognized as one of the most important determinants of game performance [14]. Maximal ball velocity is achieved through a proximal-to-distal manner; this movement allows momentum of force to transfer from the lower limb and/or pelvis through the trunk to the throwing arm, thereby enabling higher velocities of the shot [26]. During the game, the majority of shots are performed using two shooting techniques: a three-step jump shot and a standing set shot from the ground. Both techniques use two di fferent kinetic strategies (braking the body with lead leg in the standing set shot vs. opposed leg movement during the flight phase of the three-step jump shot) [27,28], while ball velocity in both is influenced by an optimal proximal–distal principle, trunk movement, and maximal arm rotation [26,28]. It is well established that elite players are able to maintain an optimal proximal-to-distal principle and arm movement while performing di fferent shooting techniques [27]. Lower ball velocity has been associated with lower strength in the lower and upper limbs, leading to ine fficient transfer of power from the proximal (pelvis, trunk) to distal (shooting arm) parts of the body [29]. Backcourt players and wings shoot the ball faster compared to pivots or goalkeepers [14,15,30]. For overhead throws, only inconsistent correlations have been reported between ball velocity and anthropometric characteristics or physical performance, and this is likely due to the complex nature of this movement [10,11,13,31,32]. Body height and weight were the only anthropometric characteristics significantly correlated with ball velocity of the standing shot [11] and/or three-step running shot [10,13,31], whereas two additional studies reported significant correlations with lower limb strength (1-RM half back squat) [31], standing long jump, 30 m sprint, and maximal oxygen uptake (estimated from 20 m shuttle run) [31]. Other studies have failed to detect such correlations [11,13]; therefore, additional studies are warranted to transfer these findings into training settings.

Based on the identified gaps in the knowledge of the anthropometric characteristics, maximal strength and power performance, and handball shooting performance of elite handball players, our study consisted of three aims. The first aim of the study was to provide further evidence on the isokinetic maximal strength and potential limb imbalances between playing positions in elite male handball players. The second aim was to examine the di fferences in anthropometric characteristics, sprinting and vertical jump performance between playing positions, and the last aim was to investigate the correlations between handball-specific performance (e.g., ball velocity) and selected anthropometric characteristics and physical performance indicators.

#### **2. Materials and Methods**

## *2.1. Study Design*

The study was designed as a cross-sectional study of a sample of elite Kosovo handball players. Measurements were conducted two weeks before the start of a competitive season, at the end of August 2019. Testing procedures were split into three days. On the first day anthropometric characteristics (height, weight, wingspan, and thigh circumference) and body composition (skeletal muscle mass and fat mass) were measured, and familiarization with all testing procedures was conducted. On the second day, following a standardized warm-up procedure, sprinting performance (20 m sprints), vertical jump performance (CMJ and SJ), and shooting performance (shooting velocity of three-step set shot and jump shot) were assessed. Finally, during the last day measurements of unilateral isokinetic knee flexor and extensor torque at 60◦/s and 180◦/s were conducted after the standardized warm-up. Forty-eight hours of rest were given between the second and third testing day to minimize any potential e ffects of fatigue. Testing procedures were performed by experienced strength and conditioning specialists.
