Search

Right ventricular (RV) (dys)function determines outcomes in pulmonary hypertension (PH). We previously found that asymmetric RV myocardial work (MW) corresponds with inefficient RV function in experimental PH models. We therefore aimed to investigate regional distribution of RV MW and its correlation with catheter hemodynamics in children with PH. RV MW was calculated by longitudinal strain and simultaneous catheter pressure measurements in 14 patients with PH. Wasted MW was defined as the ratio of inappropriate myocardial lengthening to favorable shortening work. Segment‐wise and averaged MW and wasted MW were evaluated at baseline and during pulmonary vasodilation therapy with oxygen and nitric oxide, and their relationship to hemodynamic measurements was analyzed. We found that MW was higher for the lateral wall than the septum: 1013 ± 374 mmHg · % versus 532 ± 190 mmHg · % at baseline. Wasted MW ratio did not differ significantly between wall regions. Pulmonary vasodilators slightly reduced mean pulmonary artery pressure and was accompanied by a more symmetrical MW distribution. Averaged MW correlated with the rate of RV pressure development (dP/dt maximum) and decay (dP/dt minimum) at all conditions (p ≤ $\le $ 0.047). The results suggest that MW contribute to, and may be used as a marker of, systolic and diastolic efficiency in the PH RV. [ABSTRACT FROM AUTHOR]

Introduction. Swimming is an athletic discipline that largely involves the upper limbs. Due to the driving and propulsive function, there is a heavy involvement of almost all muscles of the arm. Painful shoulder syndrome (PSS) is considered to be one of the main causes of interference with an effective and correct movement of the underwater stroke, which is a fundamental element of functionality in this discipline. The aim of this study was to evaluate whether PSS affects upper limb function in competitive swimmers. Material and methods. Thirty-two swimmers aged 17-24 years with at least 2nd sport class participated in the study. The swimmers were divided into two groups: group I - the experimental group, with subjects reporting pain in the shoulder area, and group II - the control group (sub-jects without pain in the shoulder area). Isokinetic tests at 60°/s, 180°/s, and 300°/s, hand grip strength tests, and upper limb power measurements on a swim ergometer were performed. The standard visual analogue pain scale (VAS) was used to assess the severity of pain. Results. There were significant relationships between hand grip and pulling force. Hand grip also strongly correlated with peak torque in all considered limb movements. The other examined parameters did not show statistical significance. Conclusions. Despite the significant results of the study component, there was no significant in-fluence of painful shoulder syndrome on performance levels. [ABSTRACT FROM AUTHOR]

This study aimed to determine changes in the kinematics of sprint steps based on progressive muscular fatigue during high-intensity 350-m and 500-m trials. Twelve elite healthy male 400-m sprinters with a minimum of six years of regular sprint training experience were recruited. They were divided into two groups for the experiment: a 350-m and a 500-m trial group. Time and kinematics of sprinting step motion for specific segments, i.e., starting to final stages of each trial, were obtained using the Opto Jump-Microgate optical measurement system. The starting phase of each sprint was defined as the section without muscular fatigue (noF), and the final phase was the sprint under muscular fatigue (onF). Each last 25 m of the 50-m evaluated section containing ten complete running steps was selected for detailed statistical analysis. Various patterns of temporal and spatial variables of sprinting efforts were observed between 350-m and 500-m trials. Each trial result was influenced by significant individual changes (p < 0.05). All variables indicated that the two distances differed significantly in terms of running kinematics. This was confirmed by significant differences in the mean step frequency (p < 0.001), which presented a difference of 11.75%, and the mean step speed (p < 0.001). As a result of these changes, a hierarchical intermittent endurance training pattern was defined. The research concluded that special endurance (intermittent sprints) based on 350 m differed significantly in kinematics from sprints over 500 m. Therefore, it should be assumed that the distance of 350 m is more similar in its kinematics to the 400-m competition. This should encourage coaches and athletes to apply a 350-m distance in training developing special endurance, especially in the pre-competitive and competitive periods. [ABSTRACT FROM AUTHOR]

In elite volleyball, the serve takes an offensive form, aiming to directly score a point or significantly hinder the opponent from launching an attack. Which is why the research aimed to compare the type and effectiveness of the serve in the main round of Tauron and PlusLiga in the 2021/2022 season and update the current knowledge on the types of serves by function and gender. The study analysed observation consisted of 314 women's and men's matches. VolleyStation Pro v 1.29.5; Volleystation z o. o. Poland. Data from the main round matches that took place in the 2021/2022 season in the Polish elite league PlusLiga (182 men's matches) and Tauron Liga (132 women's matches) were used, and the regular season consisted of 2 rounds. The average percentage effectiveness of the serve in women was higher (E = 22%) than in men (E = 15%). In women, only 3 types were observed (JS, JF and W), as much as 86% of all the serves were JF serves. In men, as many as 5 types (JS, JF, FJS, FJF and W), of which over 67% were dynamic JS serves (jumping serve). The serve element has been modified over the years to obtain better effects conducive to winning. Ranging from increasing the speed of the serve, eliminating the serves from the spot in favor of the jump serves, to the use of serves to hide the correct hit of the ball ("Fake"—FFJ, FJS). [ABSTRACT FROM AUTHOR]

This study aimed to investigate an acute effect of foam rolling and tissue flossing of the Triceps Surae muscle on Achilles tendon stiffness, jump height and sprint performance at different time points. The participants were academic athletes (n = 32) aged between 22 and 24 years; randomly allocated into two groups: foam rolling (ROLL) and tissue flossing (FLOSS). The participants were tested at baseline and 5-min, 15-min, 30-min, 45-min, and 60-min after ROLL and FLOSS for Achilles tendon stiffness (ATstiffeness) at three reference locations: (1) tendon's origin, (2) ankle joint height and (3) intermuscular septum of the gastronomies muscle; countermovement jump (CMJ); and sprint performance at 15-m (SPRINT15 m). The analysis of stiffness revealed a significant decrease in ATstiffness from baseline to Post-60 (p ≤ 0.001) for three locations in the FLOSS group (p ≤ 0.001). In FLOSS, a significant increase was observed from Post-15 to Post-60 (all p≤0.001) in CMJ. We found also a significant decrease in SPRINT15 m in FLOSS in all-time points (p ≤ 0.001), however, SPRINT15 m decreased in Post-5 min, Post-15 min, and Post-30 min (p ≤ 0.001 for all) in ROLL. The current study suggested that both groups enhanced performance up to 60 min after the intervention, caused by mitigating excessive stiffness. [ABSTRACT FROM AUTHOR]

Introduction: The research examines the relationship between marathon performance and muscle stiffness changes from pre to marathon in recreational runners aged 50+ years. Methods: Thirty-one male long-distance runners aged 50-73 years participated in the experiment. The muscle stiffness of quadriceps and calves was measured in two independent sessions: the day before the marathon and 30 min after the completed marathon run using a Myoton device. Results and Discussion: The 42.195-km run was completed in 4.30,05 h ± 35.12 min, which indicates an intensity of 79.3% ± 7.1% of HRmax. The long-term, lowintensity running exercise (marathon) in older recreational runners and the low level of HRmax and VO2max showed no statistically significant changes in muscle stiffness (quadriceps and calves). There was reduced muscle stiffness (p = 0.016), but only in the triceps of the calf in the dominant (left) leg. Moreover, to optimally evaluate the marathon and adequately prepare for the performance training program, we need to consider the direct and indirect analyses of the running economy, running technique, and HRmax and VO2max variables. These variables significantly affect marathon exercise. [ABSTRACT FROM AUTHOR]

This study attempts to assess the distribution of service reception and defense, which are understood as intentional directing of the ball into specific areas of the court. The authors determined the size, location, and shape of the optimal area to which the ball should be set after the team's first touch duringservice reception and defense. The basis of analysis wasthe men's beach volleyball matches of the Swatch FIVB World Tour 2012. The authors assume that there is a common optimal area for various beach volleyball teams to which the ball is directed during service reception and defense. The study sample consisted of 64 professional beach volleyball players from the top-level teams ranked by the International Volleyball Federation (FIVB). The players' actions were observed during 32 matches from three component tournaments of the Swatch FIVB World Tour 2012. Data werecollected with a KINOVEA 0.8.15 motion tracking system. Visualizations of players' actions in different areas of the court were made. The observation and statistical analysis revealed that duringservice reception, the ball was most often directed into a 2 m x 4 m area (OA2) close to the net, near the center of the court. Thus, the court area OA2 is theoptimal area to which the balls are most often set after service reception during top-level beach volleyball matches. In defensive play, the players also directed the ball close to the net and near the center of the court; however the optimal area for defense, unlike for service reception, cannot be delineated. [ABSTRACT FROM AUTHOR]