Three dominant techniques are used for downhill turning in cross-country skiing. In this study, kinematic, kinetic, and temporal characteristics of these techniques are described and related to skier strength and power. Twelve elite female cross-country skiers performed six consecutive turns of standardized geometry while being monitored by a Global Navigation Satellite System. Overall time was used as an indicator of performance. Skiing and turning parameters were determined from skier trajectories; the proportional use of each technique was determined from video analysis. Leg strength and power were determined by isometric squats and countermovement jumps on a forceplate. Snow plowing, parallel skidding, and step turning were utilized for all turns. Faster skiers employed less snow plowing and more step turning, more rapid deceleration and earlier initiation of step turning at higher speed (r=0.80-0.93; all P(0.01). Better performance was significantly correlated to higher mean speed and shorter trajectory (r=0.99/0.65; both P(0.05) and to countermovement jump characteristics of peak force, time to peak force, and rate of force development (r=-0.71/0.78/-0.83; all P(0.05). In conclusion, faster skiers used step turning to a greater extent and exhibited higher maximal leg power, which enabled them to combine high speeds with shorter trajectories during turns.
COBISS.SI-ID: 4343473
This paper presents a new squash specific method for categorizing court locations in which the ball was played, a novel techniques for assessing the reliability of this method and presents typical shots responses in these new areas controlled for preceding shot as well as the time between shots and the handedness of the players. Twelve games were viewed using the SAGIT/Squash software and 2907 shots viewed a second time from a video image taken from behind the court with an overall agreement of 88.90% for the court location data and 99.52% for shot type.
COBISS.SI-ID: 4504497
Basketball is a team sport involving several types of players who differ in terms of body height and other morphological dimensions. This study aimed to establish and analyse the morphological characteristics of top young female European basketball players, the development levels of the morphological characteristics of three basic types of such players and any differences among them. The sample of subjects comprised 115 female basketball players aged 14.64 (±0.48) years. They were divided into three groups according to their playing position: guard (N=51), forward (N=33) and centre (N=31). The study applied 23 morphological measures, based on which the somatotype components, percentages of bone, muscle and fat tissue and other morphological indexes were calculated. Statistically significant differences (P(0.05) were established between individual types of players in terms of their body height, body mass and the three somatotype components, by using a one-way analysis of variance, whereas no such differences were identified in terms of their bone, muscle and fat tissue percentages. There were no differences even after the effect of body height was eliminated by using a multivariate analysis of covariance.
COBISS.SI-ID: 4524465
The objective of this cross sectional laboratory study was to evaluate shoulder strength asymmetry and a history of shoulder injury in a large sample of professional volleyball players of both sexes across different playing positions and skill levels. A sample of 183 volleyball players (99 men, 84 women) participated in the study. We analyzed shoulder internal-rotator and external-rotator concentric strength at 60°/s and strength ratios using repeated-measures analyses of variance. Internal-rotation strength was asymmetric in favor of the dominant side in both sexes, regardless of previous shoulder injury status. Male volleyball players had a lower shoulder strength ratio on the dominant side, regardless of previous shoulder injury status. However, this finding was valid only when hand dominance was taken into account. Female volleyball players playing at a higher level were 3.43 times more likely to have an abnormal strength ratio. Playing position was not associated with an abnormal shoulder strength ratio or strength asymmetry. In male volleyball players, the external-rotation/internal-rotation strength ratio of the dominant shoulder was lower, regardless of playing position, skill level, or a previous shoulder injury. In female players, the ratio was less only in those at a higher skill level. Isokinetic shoulder testing may reveal important information about the possible risk factors for shoulder injuries, so we recommend including it in the functional screening of volleyball players.
COBISS.SI-ID: 4503473
The objective of this cross-sectional laboratory study was to examine the influence of isokinetic-knee flexor/extensor strength measures on spike-jump (offensive) and block-jump (defensive) performance among high-level female volleyball players. The study included 82 female volleyball athletes that volunteered to participate in this study. The athletes were clustered into three achievement-groups based on their spike-jump and block-jump performances. Each group was examined vs. the isokinetic strength parameters of the knee. Discriminant canonical analysis showed that the isokinetic-strength variables were more associated with block-jump then spike-jump-performance. The eccentric isokinetic measures were relatively less important determinants of block-jump than for the spike-jump performance. Data support the hypothesis of the importance of isokinetic strength measures for the expression of rapid muscular performance in volleyball.
COBISS.SI-ID: 4536753