Hamstring stiffness and injury risk factors during the handball season in female players.

Monitoring the muscle mechanical properties and functions of female athletes throughout their training season is relevant to understand the relationships between these factors and to predict noncontact injuries, which are prevalent among female athletes. The first aim of this study was to determine whether female handball players' passive stiffness of the hamstring muscles is associated with hamstring extensibility, strength of knee flexors and extensors, and lower limb stiffness. Additionally, the study monitored fluctuations in these factors over 25 weeks. The study utilized an isokinetic dynamometer to record hamstring passive stiffness, extensibility, and hamstring and quadriceps strength of 18 young handball players. Lower limb stiffness was determined from a countermovement vertical jump conducted on a force plate. The countermovement jump involved the calculation of the peak force during the eccentric phase and the mean force during the concentric phase. The results showed a positive correlation between hamstring passive stiffness and lower limb stiffness (r = 0.660, p < 0.01), knee flexion and extension strength (r = 0.592, p < 0.01 and r = 0.497, p < 0.05, respectively), and eccentric peak force (r = 0.587, p < 0.01) during jumping. The strength of knee extensors increased significantly after 6 weeks, and hamstring stiffness after 12 weeks of training. In conclusion, the increased hamstring stiffness following training did not match other factors associated with injury risk. Therefore, preventing multifactorial injury risk requires a comprehensive approach, and monitoring one factor alone is insufficient to predict noncontact injuries in female handball players.

Relationship Between External and Internal Load Measures in Youth Beach Handball.

PURPOSE: Assessing the relationship between external load (EL) and internal load (IL) in youth male beach handball players. METHODS: A total of 11 field players from the Lithuanian U17 beach handball team were monitored across 14 training sessions and 7 matches. The following EL variables were assessed by means of inertial movement units: PlayerLoad™, accelerations, decelerations, changes of direction, and jumps and total of inertial movements. IL was assessed objectively and subjectively using the summated heart rate zones and training load calculated via session rating of perceived exertion, respectively. Spearman correlations (ρ) were used to assess the relationship between EL and IL. The interindividual variability was investigated using linear mixed models with random intercepts with IL as dependent variable, PlayerLoad™ as the independent variable, and players as random effect. RESULTS: The lowest significant (P < .05) relationship was for high jumps with objective (ρ = .56) and subjective (ρ = .49) IL. The strongest relationship was for PlayerLoad™ with objective (ρ = .9) and subjective (ρ = .84) IL. From the linear mixed model, the estimated SD of the random intercepts was 19.78 arbitrary units (95% confidence interval, 11.75-33.31); SE = 5.26, and R2 = .47 for the objective IL and 6.03 arbitrary units (95% confidence interval, 0.00-7330.6); SE = 21.87; and R2 = .71 for the subjective IL. CONCLUSIONS: Objective and subjective IL measures can be used as a monitoring tool when EL monitoring is not possible. Coaches can predict IL based on a given EL by using the equations proposed in this study.

Fitness, Technical, and Kinanthropometrical Profile of Youth Lithuanian Basketball Players Aged 7-17 Years Old.

Optimizing basketball performance during the stages of long-term athlete development require to identify the trainability and variation of specific technical skills, when adjusting for anthropometric changes. The aim of this study was to describe differences in height, body mass, arm span, and technical-related fitness (movement, dribbling, shooting) along the long-term development of 7-17 years Lithuanian basketball players. This cross-sectional analysis involved a total of 1051 basketball players from the Sabonis Basketball Center in Lithuania. Testing sessions were performed during 1 day of the competition period in an indoor court. The participants performed technical-related fitness tests to assess dribbling (control dribble, 20 m dribble, two balls of 20 m dribble, Illinois agility dribble), shooting (30 free-throw shoots, 1 min shooting, modified medium and long-range shots, close range shots) and defensive movements. The dribbling skills had substantial improvements (7 to 8-years-old: 20 m sprint with dribbling, effect size = 1.86; control dribble effect size = 2.18; 9 to 10-year-old: 20 m sprint with dribbling, effect size = 1.85; Illinois agility test with dribbling effect size = 1.82). Changes in defensive movement occurred mostly at the 14-15-age period. The best periods to develop dribbling and shooting skills were between 7-10 and 12-13 years, whereas defensive movements can be trained in later adolescent years. Current results and consequent normative profiles, presented as percentile tables, allow to accurately follow the players' development.

Quantification of external and internal match loads in elite female team handball.

To assess concurrently the external and internal match loads in elite female team handball players and to verify the differences in match loads between matches characterized by different durations. Eight elite female court handball players (mean±SD; age 23.0±2.1 years; stature 173.5±4.9 cm; body mass 67.8±6.8 kg) belonging to the same elite female handball team were investigated. Individualized internal and external match loads were monitored during seven 1st Division Lithuanian Women's Handball League [Lietuvos Moteru Rankinio Lyga (LMRL)] matches and seven Women's Baltic Handball League (WBHL) matches during the 2017/18 season. The LMRL and WBHL matches were characterized by different durations (two 30-min halves and two 20-min halves for LMRL and WBHL, respectively). The investigated external load measures were total player load (PL) and PL per minute (PL.min-1), while internal load measures were match load calculated from session rating of perceived exertion (S-RPE) and percentage of maximum heart rate (%HRmax). The main outcomes revealed a PL. min-1 of ~9 AU and ~84% of HRmax per match. Moreover, significantly higher total PL (p<0.001; ES (effect size) = Moderate) and match load calculated from S-RPE (p<0.05; ES= small to moderate) were found in LMRL compared to WBHL. Conversely, no statistically significant differences were found for PL.min-1 and %HRmax between the two leagues. The main results indicate that elite female handball matches require high physical and physiological demands. Additionally, a longer match time corresponded to dissimilar responses in external and internal match loads, suggesting that coaches should monitor match loads with different strategies.