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The reasons for the overrepresentation of left-handed players (LHps) in some sports are widely discussed in the literature. In light of this debate, this study aimed to assess the associations between players’ handedness and selected performance indicators in table tennis, where LHps represent 25% of top-level players. A notational analysis was conducted on 20 men’s matches including any combination of players’ handedness. Participants were in the first 150 positions of the ITTF world ranking at the moment the matches were played. The table area of ball bouncing after serving, and the shot type used by the receiving and subsequently the serving player, were recorded for 1515 rallies. Each half of the table was divided into six equal rectangular areas. There was a significant effect of players’ handedness on percentage of ball bouncing in different areas. Specifically, LHps showed a greater capacity (or choice) to adjust the serve (in terms of areas of ball bouncing) than right-handed players (RHps) according to the opponent’s handedness. Furthermore, LHps used offensive shots more frequently. In conclusion, both play strategy and characteristics such as higher offensiveness, together may contribute to the success of LHps in table tennis. These findings emphasise the need for a multifactorial approach in future research aiming to understand why LHps may be advantaged in different sports.

Introduzione Questo studio ha esaminato gli effetti dell’ esercizio fisico combinato aerobico e di forza supervisionato su condizione fisica, profilo metabolico, funzionalità epatica e qualità di vita in trapiantati di fegato (LTR). Metodologia 40 LTR sono stati assegnati al gruppo di esercizio supervisionato (gruppo A, n=20) o al gruppo di controllo (gruppo B; n=20). La potenza aerobica, la forza muscolare, il profilo metabolico, la funzionalità epatica e renale e la qualità di vita sono stati valutati al basale, dopo 6 e 12 mesi. Il gruppoA ha svolto un programma di esercizio fisico combinato supervisionato 3 volte/settimana per 12 mesi. Il gruppoB ha ricevuto solo raccomandazioni generali sull'esercizio senza supervisione. Risultati 29 LTR hanno completato lo studio (gruppoA, n=17, gruppoB, n=12). Interazioni significative sono emerse sulla potenza aerobica (P=0.05), sulla forza generale (P=0.004), sulla forza muscolare degli arti superiori (P=0.025) e sulle scale della salute generale (P=0.014), vitalità (P=0.026) e salute mentale (P=0.014), dove il gruppoA migliora e il gruppo B peggiora nel tempo. È stata rilevata un'interazione significativa per la glicemia (P=0.037) che nel tempo è diminuita nel gruppo A e aumentata nel gruppoB. E’ stato rilevato un significativo incremento nel tempo del BMI (P=0.003) e della forza muscolare degli arti inferiori (P=0.019) in entrambi i gruppi con %massa grassa inferiore nel gruppoA rispetto al gruppoB. Conclusioni L’ esercizio fisico combinato supervisionato per 12 mesi può migliorare la potenza aerobica, la forza muscolare e la qualità di vita nei LTR, riducendo la glicemia senza compromettere la funzionalità epatica e renale.

Ivan Malagoli Lanzoni1, Rocco Di Michele2 and Gabriele Semprini2 1 School of Pharmacy, Biotechnology and Sport Science, University of Bologna, Italy 2 Department of Biomedical and Neuromotor Sciences, University of Bologna, Italy FIFTY YEARS OF TOP-CLASS TABLE TENNIS WORLD RANKING Abstract The aim of this study was to analyse of some aspects of the world table tennis rankings in order to better understand the historical and technical evolution of this sport. One world ranking for every year from 1967 to 2017 was examined by identifying the first 10 male (M) and female (F) players. For each player the, handedness (left- or right-handed), grip (classic or pen-holder), style of play (offensive or defensive), and nationality, were recorded. All data are presented as percentages. Left-handed are overrepresented (M: 25.4; F: 22.6) with respect to the normal population (10-13%). The classic grip is the most used (M: 72.8; F: 72.5). In M players, a slight increase was observed while in F since 1985 until today the classic grip showed an important increase. The predominant playing style is offensive (M: 93.4; F: 88.9) with an increasing trend in M and F. In M the most represented nation is China (39.6) followed by Sweden (12.8), Japan (7.8), Korea (5.1), Germany (4.9), Yugoslavia (4.3). In F: China (50.4), Japan (8.8), Korea (7.3), PRK (4.6), USSR (3.1), Singapore (2.9), and Hungary (2.4). In the last 50 years the Asian athletes have dominated the world rankings (M: 56.5; F: 50.4). This domination started in 2003 for M, after a period of substantial balance with Europeans and for F it constantly increases since 1971. Asians are followed by Europeans (M: 43.3; F: 18.8) and Americans (M: 0.2; F: 0.1).

Purpose: This study aimed to compare the acute effects of uphill repeated sprinting "with long recovery" (RS) and uphill intermittent running (IR) training on heart rate (HR) and blood lactate (BL) responses. Methods: Thirteen young male soccer players randomly performed in two separate occasions, on a slope (10 %), an RS and an IR session. RS consisted of three sets of eight maximal uphill 20-m sprints with long (90 s) recovery between sprints, and 8 min passive rest between sets, whereas IR consisted of 24 repetitions of 22-m sub-maximal (95 % of maximum speed achieved in an incremental test) uphill runs interspersed by a 15-s downhill walking recovery, lasting for a total duration of 8 min. Results: The mean HR, expressed as the percentage of HRMAX, was significantly higher in IR than in RS (86.1 ± 3.1 vs. 77.0 ± 4.5 %, respectively, p < 0.05). Conversely, BL measured after 3 min was significantly higher in RS (5.9 ± 1.1 mmol L-1) than in IR (2.9 ± 1.2 mmol L-1, p < 0.05). Conclusions: The differences found between RS and IR may be attributed to the different work/recovery ratios and speed characteristics. Therefore, uphill IR seems more suitable when the target is to tax the aerobic system, while RS may be more suitable when the focus is on stimulating the speed without increasing the metabolic demand. © 2014 Springer-Verlag Italia.

Tracking of markers placed on anatomical landmarks is a common practice in sports science to perform the kinematic analysis that interests both athletes and coaches. Although different software programs have been developed to automatically track markers and/or features, none of them was specifically designed to analyze underwater motion. Hence, this study aimed to evaluate the effectiveness of a software developed for automatic tracking of underwater movements (DVP), based on the Kanade-Lucas-Tomasi feature tracker. Twenty-one video recordings of different aquatic exercises (n = 2940 markers' positions) were manually tracked to determine the markers' center coordinates. Then, the videos were automatically tracked using DVP and a commercially available software (COM). Since tracking techniques may produce false targets, an operator was instructed to stop the automatic procedure and to correct the position of the cursor when the distance between the calculated marker's coordinate and the reference one was higher than 4 pixels. The proportion of manual interventions required by the software was used as a measure of the degree of automation. Overall, manual interventions were 10.4% lower for DVP (7.4%) than for COM (17.8%). Moreover, when examining the different exercise modes separately, the percentage of manual interventions was 5.6% to 29.3% lower for DVP than for COM. Similar results were observed when analyzing the type of marker rather than the type of exercise, with 9.9% less manual interventions for DVP than for COM. In conclusion, based on these results, the developed automatic tracking software presented can be used as a valid and useful tool for underwater motion analysis. Key PointsThe availability of effective software for automatic tracking would represent a significant advance for the practical use of kinematic analysis in swimming and other aquatic sports.An important feature of automatic tracking software is to require limited human interventions and supervision, thus allowing short processing time.When tracking underwater movements, the degree of automation of the tracking procedure is influenced by the capability of the algorithm to overcome difficulties linked to the small target size, the low image quality and the presence of background clutters.The newly developed feature-tracking algorithm has shown a good automatic tracking effectiveness in underwater motion analysis with significantly smaller percentage of required manual interventions when compared to a commercial software.

Background Walking in water (WW) is frequently used as an aquatic exercise in rehabilitation programs for the elderly. Understanding gait characteristics of WW is of primary importance to effectively design specific water-based rehabilitation programs. Moreover, as walking speed in water is reduced with a possible effect on gait parameters, the age- and environment-related changes during WW have to be investigated considering the effects of instantaneous walking speed. Research question: how do gait kinematic characteristics differ in healthy elderly between WW and on land walking condition (LW)? Do elderly show different walking patterns compared to young adults? Can these kinematic changes be accounted only by the different environment/age or are they also related to walking speed? Methods Nine healthy elderly participants (73.5 ± 5.8 years) were acquired during walking in WW and LW at two different speeds. Kinematic parameters were assessed with waterproofed inertial magnetic sensors using a validated protocol. The influence of environment, age and walking speed on gait parameters was investigated with linear mixed models. Results Shorter stride distances and longer stride durations were observed in WW compared to LW. In the sagittal plane, hip and knee joint showed larger flexion in WW (>10deg over the whole stride and ∼28deg at foot strike, respectively). Furthermore, lower walking speeds and stride distances were observed in elderly compared to young adults. In the sagittal plane, a slightly more flexed hip joint and a less plantarflexed ankle joint (∼9 deg) were observed in the elderly. Significance: The results showed the importance of assessing the walking speed during WW, as gait parameters can vary not only for the effect environment but also due to different walking speeds.

The present study aimed to explore the variability of the arm-stroke temporal descriptors between and within laps during middle-distance swimming event using IMMUs. Eight male swimmers performed a 200-m maximum front-crawl in which the inter-lap and intra-lap variability of velocity, stroke rate, stroke-phases duration and arm-coordination index were measured through five units of IMMU. An algorithm computes the 3D coordinates of the wrist by means the IMMU orientation and the kinematic chain of upper arm biomechanical model, and it recognizes the start events of the four arm-stroke phases. Velocity and stroke rate had a mean value of 1.47 &plusmn, 0.10 m&middot, s&minus, 1 and 32.94 &plusmn, 4.84 cycles&middot, min&minus, 1, respectively, and a significant decrease along the 200-m (p &lt, 0.001, &eta, 2 = 0.80 and 0.47). The end of each lap showed significantly lower stroke rate compared to the start and the middle segment (p &lt, 0.05, 2 = 0.55). No other significant inter-lap and intra-lap differences were detected. The two main findings are: (i) IMMUs technology can be an effective solution to continuously monitor the temporal descriptors during the swimming trial, (ii) swimmers are able to keep stable their temporal technique descriptors in a middle-distance event, despite the decrease of velocity and stroke rate.

The present study aims to assess the position of the racket, and racket height with respect to the floor, during the table tennis top spin stroke. A stereophotogrammetric system (Smart-D, BTS, 8 cameras, 550 Hz) was used to track the table tennis racket during cross-court (CC) and long-line (LL) shots. Ten national level players completed ten CC and ten LL top spin strokes responding to a robot machine. The racket motion throughout the shot showed specific technical characteristics: the minimum height of the racket was detected during the backswing phase, racket height at the end of backswing phase (maximal distance racket/table) was higher than the minimum, height at the racket maximum velocity (ball/racket impact) was greater than the net’s height. Furthermore, the maximum height of the racket occurred at the end of the forward swing. No differences in these kinematic variables between CC and LL were found. Conversely, a higher inclination of the racket at the moment of maximum speed was detected in LL vs. CC. From a practical perspective, the present findings suggest that table tennis players need to introduce specific exercises in order to increase the height of the racket during the forehand top spin stroke, to improve its effectiveness.

The passive drag (Dp) during swimming is affected by the swimmer&rsquo, s morphology, body density and body position. We evaluated the relative contribution of morphology, body composition, and body position adjustments in the prediction of a swimmer&rsquo, s Dp. This observational study examined a sample of 60 competitive swimmers (31 male and 29 female) with a mean (&plusmn, SD) age of 15.4 &plusmn, 3.1 years. The swimmer&rsquo, s Dp was measured using an electro-mechanical towing device and the body composition was assessed using a bioelectrical impedance analyser. Body lengths and circumferences were measured in both the standing position and the simulated streamlined position. Partial correlation analysis with age as a control variable showed that Dp was largely correlated (p &lt, 0.05) with body mass, biacromial- and bi-iliac-breadth, streamline chest circumference and breadth. Body mass, Body Mass Index, chest circumference and streamline chest circumference showed a significant and moderate to strong effect (&eta, 2 &gt, 0.55) on Dp. Body mass was the best predictor of Dp explaining 69% of the variability. These results indicate that swimmers with lower Dp values were: (i) slimmer, with lower fat and fat-free mass, (ii) thinner, with lower shoulder breadth, chest circumference, and streamline trunk diameters (iii), shorter, with lower streamline height. These findings can be used for talent identification in swimming, with particular reference to the gliding performance.

The current study examined how sleep may be influenced by the scheduling of training and match load within 10 youth-soccer players. Sleep was measured over a 14-day in-season period using a commercially available wireless sleep monitor. Each collected sleep variable; lights out, sleep latency, total sleep time wake after sleep onset and final awakening, was compared for the specific day within the training schedule (e.g. match day [MD], day after match [MD + 1]) and to training/match load (high-speed distance (>5.5 m/s) [HSD] and rating of perceived exertion. The data were analysed using mixed models and effect sizes, to describe the magnitude of effects that training schedule and training load may have on sleep. A reduction of sleep duration was observed on the day after the match (MD + 1) in relation to the training days preceding the match (MD-2: −65 min, ES: 0.89 ± 0.79; MD-1 −61 min, ES: 0.82 ± 0.64) and reduction on match day (+45 min; ES: 1.91 ± 1.69). This may suggest youth-soccer players actively change their sleep scheduling behaviours in relation to the imposed soccer schedule. Increased high-speed running (for every 100 m) showed a small increase to total sleep time (+9 min; ES: 0.48 ± 0.31). This may suggest that increases in training load may be associated with small increases in sleep quantity. Such observations may highlight that the type of day and the associated load within the training microcycle may have important consequences for sleep within youth-soccer players.

Background and aims Despite the excellent long-term outcomes in liver transplant (LT) recipients, several medical complications related to lifestyle still represent an issue. This study examined the effects of a 12-month supervised aerobic and strength training program on the aerobic capacity, muscle strength, metabolic profile, liver function, and quality of life of a cohort of LT recipients. Methods LT recipients with stable liver function were assigned to interventional exercise (group A) or usual care (group B). Aerobic capacity, muscle strength, metabolic profile, liver and kidney function, and health-related quality of life were assessed at baseline and after 6 and 12 months. Group A attended supervised training sessions 3 times per week for 12 months. Group B received general recommendations about home-based exercise. Results Forty patients from 6 Italian LT centers were randomized. Twenty-nine (72.5%, men-to-women ratio 23:6, mean age, 52 ± 8 years) LT recipients completed the study. Baseline characteristics were similar between groups except for body mass index and time from LT. No episode of acute rejection nor increase of transaminases occurred. Maximum workload and body mass index increased in both groups over time, but fasting glucose significantly decreased in group A (94.0 ± 15.0 mg/dL vs 90.0 ± 17.0 mg/dL; P = .037) and increased in controls (95.0 ± 24.0 mg/dL vs 102.0 ± 34.0 mg/dL, P = .04). Upper limb muscle strength increased only in supervised LT recipients. Vitality and general and mental health domains significantly improved after physical exercise. Conclusions Supervised combined training was safe and effective in increasing aerobic capacity, muscle strength, and quality of life and in improving glucose metabolism in stable LT recipients.

Context:Kinematic asymmetry is believed to be associated with elevated risk for muscle injury, but little is known about the links between hamstring injuries and asymmetry of sprinting mechanics.Objective:To evaluate the value of kinematic analysis of sprinting for the detection of injury-related asymmetry in athletes with a history of hamstring strain.Participants:Six sub-elite male sprinters, including two who sustained a hamstring strain injury.Outcome Measures:Absolute differences between left and right symmetry indices and symmetry angles were both calculated for ground contact time and selected angular displacements. Measurements were acquired at foot strike, during the stance phase, and at toe-off.Results:At toe-off, injured athletes exhibited greater knee flexion and less hip extension for the injured extremity compared to the uninjured extremity. Symmetry indices for these variables markedly exceeded an established 15% threshold for clinically relevant asymmetry. Each of the uninjured athletes exhibited a high degree of symmetry for all parameters, with mean values for symmetry indices significantly lower than the 15% threshold (P < 0.05).Conclusions:Kinematic analysis of sprinting asymmetry appears to be valuable for identification of elevated risk for hamstring injury.

Previous studies indicate that the kinesthetic differentiation ability is crucial in different sports (Pakosz, 2013), in motor control (Grsegorz, 2011), in sports performance (Bankosz, 2015) and requires a specific education (Ziemowit, 2012).The extreme diffusion of extensive multilateral approach in primary school, compared with children who are increasingly sedentary, doesn't seem enough to develop specific ability of motor coordination (balance, kinesthetic differentiation, rhythmic control, etc.).This study aimed to compare, in primary school children (mean age: 9 yrs), the effects of a multilateral extensive activity programme (MED), oriented to dexterity, and multilateral intensive activity programme (MIK), oriented to kinaesthetic differentiation. 77 boys (MED:39; MIK:38) and 76 girls (MED:38; MIK:38) were involved. In both groups, the activity consisted of one 2-hr sessions/week throughout the school year. The following test battery was administered: BrikTest differentiation (BTD), Generic throw at a fixed distance (GTF), Generic throw on increasing distances (CTI), Generic blindfolded throw (BTF), Basket Throw (SBT). The tests were administered in T1 (October), T2 (January) and T3 (May).There has been a significant enhancement in MIK Group both in T2 (GTF, CTI, BTF) that in in T3 (BTD, GTF, CTI, BTF SBT). BTD and SBT improved in T3 only in older children (grade 5), while SBT improved in T3 only in younger children (grade 3 and 4) but not in the oldest (grade 5). Gender differences occurred only in CTI.The ability to transfer generic throw (GTF, CTI) to specific throw (SBT) appears effective from the age of 10 years but not at previous ages. The study seems to suggest the idea that the MED if supplemented by MIK and enlarged to other abilities (balance, rhythm, etc), can be a good strategy to develop the motor skills of children nowadays as they have little time to exercise quantitative but also qualitative physical activity. Keywords: multilateral activities, Physical Education, children, primary school, motor skills

This study aimed to compare, in high-school students (mean age: 15 yrs), the effects of a traditional (TR) and a highly emotional (HE) physical education program. 96 boys (TR:46; HE:50) and 69 girls (TR:34; HE:35) were involved. The activity consisted of two hour/week throughout the school year. HE included pre-acrobatics, climbing, diving, skating, frisbee, beach tennis, and sailing. In TR, typical activities characterising the national PE programs were proposed. The following test battery was administered: standing broad jump (SBJ), hand-grip strength (HG), endurance (Leger), dynamic balance, sit&reach (SR). Furthermore, the students completed the following questionnaires: Self-Efficacy, Psychobiosocial states (PBS), Physical Activity Enjoyment Scale (PACES), Physical Self-Description Questionnaire (PSDQ). Boys of both groups significantly increased HG strength (2.6 kg), and girls of the TR group. Both groups and sexes showed slightly (1-5 cm) increased SBJ, slightly decreased endurance, and improved balance (0.5-0.7 m/s). SR showed a significant improvement (3 cm) in the TR group (both sexes). Self-Efficacy decreased in boys of the HE group, and increased in girls of the TR group. Boys showed increased scores in the PBS and PACES, whereas girls showed small improvements in the PBS. Boys of the TR group improved in the PSDQ (self-esteem factor), whereas girls of the TR group showed a worsened score. Finally, in the TR group, all students improved the score in the PSDQ activity scale. In summary, varied effects of PE were observed on physical fitness and psychosocial variables, according to the sex of students and the type of proposed activity.