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This study aimed to evaluate developmental patterns in athletic performance during youth and determine their association with changes in physical fitness. The testing included three athletic performance (i.e. ball speed in pitching, swing velocity in batting, 30-metre sprint time) and two physical fitness tests (i.e. medicine ball [MB] back throw and modified star excursion balance test [SEBT]). Data from 235 players (557 measurements) aged 6 to 14 were eligible for a longitudinal evaluation. The statistical analysis was based on the latent growth curve models of the athletic performance development process and the random-effect panel data multivariate regression analysis for ball speed, swing velocity, and 30-metre sprint time. The 30-metre sprint time showed a small curvature but an accelerated increase around 12‒13 years old. However, the ball speed, swing velocity, and modified SEBT demonstrated a slower or less accelerated change in the developmental pattern starting around 12‒13 years old. Multivariate longitudinal analysis revealed that developmental change in athletic performance was positively associated with age and MB back throw. Our findings highlight the developmental patterns of athletic performance associated with baseball exhibiting stagnation as well as acceleration, which may help develop effective age-appropriate strategies for improving performance in youth baseball players. [ABSTRACT FROM AUTHOR]

Background: Kinematic parameters predictive of pitch velocity have been evaluated in adolescent and collegiate baseball pitchers; however, they have not been established for high school or professional pitchers. Purpose: To create multiregression models using anthropometric and kinematics features most predictive for pitch velocity in high school and professional pitchers and compare them with prior multiregression models evaluating other playing levels. Study Design: Descriptive laboratory study. Methods: High school (n = 59) and professional (n = 337) baseball pitchers threw 8 to 12 fastballs while being evaluated with 3-dimensional motion capture (480 Hz). Using anthropometric and kinematic variables, multiregression models for pitch velocity were created for each group. A systematic review was conducted to determine previous studies that established kinematic models for ball velocity in youth, high school, and collegiate pitchers. Results: Leg length was predictive of pitch velocity for high school and professional pitchers (P <.001 for both). When compared with previously established models for pitch velocity, almost all groups were distinct from one another when assessing age (P maximum <.001), weight (P max =.0095), and pitch velocity (P max <.001). Stride length was a significant predictor for the youth/high school pitchers, as well as the current study's high school and professional pitchers (P <.001 for all). Maximal shoulder external rotation (collegiate: P =.001; professional: P <.001) and maximal elbow extension velocity (high school/collegiate: P =.024; collegiate: P <.001; professional: P =.006) were shared predictors for the collegiate and current study's professional group multiregression models. Trunk flexion at ball release was a commonly shared predictor in the youth/high school (P =.04), high school/collegiate (P =.003), collegiate (P <.001), and the current study's professional group (P <.001). Conclusion: Youth, high school, collegiate, and professional pitchers had unique, predictive kinematic and anthropometric features predictive of pitch velocity. Leg length, stride length, trunk flexion at ball release, and maximal shoulder external rotation were predictive features that were shared between playing levels. Clinical Relevance: Coaches, clinicians, scouts, and pitchers can consider both the unique and the shared predictive features at each playing level when attempting to maximize pitch velocity. [ABSTRACT FROM AUTHOR]

Mg5Zn0.2Ca is a promising alloy for medical tools owing to its excellent biocompatibility and biodegradability. This study presents the impact of surface mechanical attrition treatment (SMAT) parameters, explicitly colliding balls velocity (1, 5, and 10 m/s), and surface coverages (500, 1000, and 2000%), on the microstructure, hardness, and residual stress. SMAT forms a layer with a gradient in hardness, crystallite size, and twins. The surface hardness, which ranges between 68 and 118 HV0.05, increases with increased ball velocity and surface coverage. High ball velocity (10 m/s) and surface coverage (2000%) induce high compressive residual stress of about −175.5 MPa at ~600 µm depth. The specimens SMATed with a ball velocity of 5 m/s exhibit the higher surface compressive residual stress for all surface coverages. The maximum compressive residual stress of about −153.5 MPa is observed at the surface for the specimens SMATed at 5 m/s ball velocity and 500% coverage. The overall analysis reveals that the specimen treated at 10 m/s ball velocity and 2000% surface coverage exhibits the most refined grain structure, finely and densely distributed twins, maximum SMAT-induced thickness (~3000 µm), highest surface hardness (~2.1 times the non-SMATed specimen's hardness), and maximum compressive residual stress. [ABSTRACT FROM AUTHOR]

Purpose: In elite team handball, talent identification and selection of the best young players is a fundamental process in several national federations and clubs; however, literature addressing the specific game-based performance in team handball is almost nonexistent. Consequently, the aim of the study was to assess and compare the team-handball-specific game-based performance of elite male team handball players of different ages. Methods: Twelve under-23, 10 under-19, 10 under-17, and 10 under-15 elite male players performed the team-handball game-based performance test. During testing, oxygen uptake, heart rate, sprinting time in defense, offense, fast breaks, and fast retreats, as well as ball velocity and jump height in the jump shot, were measured. Results: Significant differences (P <.05) between under-23, under-19, under-17, and under-15 players were found for absolute peak oxygen uptake, defense, offense and fast break time, ball velocity, and jump height in the game-based performance test, as well as in body weight and height. Conclusion: The results revealed that with increasing age, elite male team handball players are heavier and taller (body weight and height); faster (team-handball offense, defense, and fast break); jump higher and throw faster (in the team-handball jump shot); and perform better aerobically (absolute peak oxygen uptake). The better performance in the under-23 and under-19 players compared with male adult players competing in a lower National Federation league (not on top-elite level) demonstrates that highly specific game-based physical performance determines the potential for developing young male team handball players for competition at the top level. [ABSTRACT FROM AUTHOR]

The tennis serve is closely related to the quality of the tennis match. However, the isokinetic parameters associated with the tennis serve are still unclear. The aim of this study was to investigate the relationships between ball velocity and isokinetic shoulder strength in tennis serve and to determine isokinetic strength parameters that can predict tennis serve velocity. A total of 13 elite male athletes (16.8 ± 1.5 years) voluntarily participated in the study. The athletes’ shoulder internal-external rotation, extension-flexion and abduction-adduction strengths were measured with 5-5-15 repetitions at 60°/s, 180°/s, 240°/s angular velocities. Later, the athletes’ 1st, 2nd, and average serve ball speeds were determined using a handheld radar gun. Significant correlations were found between ball speed and isokinetic tennis serve strength (r = 0.556–0.819; p < 0.05). The correlations between ball speed and isokinetic strength performance were higher at 180°/s and 240°/s angular velocities. Extension (240°/s; r = 0.819), flexion (180°/s; r = 0.755), abduction (240°/s; r = 0.733), adduction (240°/s; r = 0.684) and internal rotation (180°/s; r = 0.803) were highly correlated with ball velocity. These findings suggest that strength training to increase the ball speed of the tennis serve should be performed fast at high angular velocities and planning should focus on the strength of extension, flexion, abduction, adduction and internal rotation. [ABSTRACT FROM AUTHOR]

Abstract Background Although softball players are often required to play in hot environments, scarce evidence is available regarding the effects of ice slurry ingestion on body temperature and pitching performance in softball pitchers in a hot environment. Thus, this study investigated the effects of ice slurry ingestion before and between innings on body temperature and softball pitching performance in a hot environment. Methods In a randomized crossover design, seven heat-acclimatized amateur softball pitchers (four males and three females) completed simulated softball games consisting of 15 best-effort pitches per inning for seven innings with between-pitch rest intervals of 20 s. Participants were assigned to either a control trial (CON: ingestion of 5.0 g·kg−1 of cool fluid [9.8 ± 2.2 °C] before simulated softball games and 1.25 g·kg−1 of cool fluid between inning intervals) or an ice trial (ICE: ingestion of ice slurry [− 1.2 ± 0.1 °C] based on the same timings and doses as the CON). Participants performed both trials in an outdoor ground during the summer season (30.8 ± 2.7 °C, 57.0 ± 7.9% relative humidity). Results Ice slurry ingestion before the simulated softball game (pre-cooling) resulted in a greater reduction in rectal temperature compared with cool fluid ingestion (p = 0.021, d = 0.68). No significant differences were observed between the trials in rectal temperature changes during the simulated softball game (p > 0.05). Compared to the CON, heart rate during the game was significantly decreased (p

The purpose of this study was to compare the effects of plyometric training and mixed-methods power training on the ball velocity and kinematic parameters of the instep kick after muscle fatigue in university futsal players. The study recruited 42 futsal players with an average age of 20.2 years, weight of 66.04 kg, and height of 172.7 cm. The subjects were divided into three groups comprising a control group (regular futsal training), a plyometric training group, and a mixed-methods training group. The training program was conducted for 8 consecutive weeks, with two training sessions per week. The researchers measured ball and ankle velocities, as well as hip and knee angular velocities, before the training program, after 8 weeks of training, and after inducing muscle fatigue. Collected data were analyzed using multivariate analysis of variance (MANOVA). The results showed that after the 8-week training program, both the plyometric training group and the mixed-methods training group showed an increase in mean ball and ankle velocities, as well as hip and knee angular velocities. However, there was no significant difference between the plyometric and mixed-methods training groups. Both training groups exhibited significantly higher values compared to the control group (p < .05). Similarly, the study found no significant differences between the plyometric training group and the mixed-methods training group in these variables after inducing muscle fatigue. However, both training groups had significantly higher values compared to the control group (p < .05). In summary, the study suggests that both plyometric training and mixed-methods power training can improve the ball velocity and kinematic parameters of the instep kick in foot athletes after muscle fatigue. The findings of this study have implications for training programs aimed at enhancing the performance of futsal players. [ABSTRACT FROM AUTHOR]

Aim: To analyse the validity of the mobile application (Athla Velocity) used to measure ball speed. Method: A total of 67 volunteer male tennis players with a mean age of 24.94 ± 4.91 years participated in the study. In all measurements, the successful 10 service strike velocity made by the athletes in the determined area were evaluated. Each service strike was measured concurrently using both the Stalker Solo 2 radar device and the Athla Velocity application. Bland-Altman and regression analyses were used to determine the validity. Results: A high positive correlation was found between the radar device and Athla Velocity Application measurements (ICC = 0.970, r² = .989). In addition, according to the Bland-Altman analysis, the measurement results of the two methods were found to be within the calculated limited area to a large extent. Conclusion: It has been determined that the Athla Velocity application can measure 98% close to the Stalker Pro 2 device in ball velocity measurement. As a result, it can be said that the Athla Velocity application can be used validly in ball velocity measurements. [ABSTRACT FROM AUTHOR]

Background: Although softball players are often required to play in hot environments, scarce evidence is available regarding the effects of ice slurry ingestion on body temperature and pitching performance in softball pitchers in a hot environment. Thus, this study investigated the effects of ice slurry ingestion before and between innings on body temperature and softball pitching performance in a hot environment. Methods: In a randomized crossover design, seven heat-acclimatized amateur softball pitchers (four males and three females) completed simulated softball games consisting of 15 best-effort pitches per inning for seven innings with between-pitch rest intervals of 20 s. Participants were assigned to either a control trial (CON: ingestion of 5.0 g·kg−1 of cool fluid [9.8 ± 2.2 °C] before simulated softball games and 1.25 g·kg−1 of cool fluid between inning intervals) or an ice trial (ICE: ingestion of ice slurry [− 1.2 ± 0.1 °C] based on the same timings and doses as the CON). Participants performed both trials in an outdoor ground during the summer season (30.8 ± 2.7 °C, 57.0 ± 7.9% relative humidity). Results: Ice slurry ingestion before the simulated softball game (pre-cooling) resulted in a greater reduction in rectal temperature compared with cool fluid ingestion (p = 0.021, d = 0.68). No significant differences were observed between the trials in rectal temperature changes during the simulated softball game (p > 0.05). Compared to the CON, heart rate during the game was significantly decreased (p < 0.001, d = 0.43), and handgrip strength during the game was significantly increased (p = 0.001, d = 1.16) in the ICE. Ratings of perceived exertion, thermal comfort, and thermal sensation were improved in the ICE compared to those in the CON (p < 0.05). Ball velocity and pitching accuracy were not affected by ICE. Conclusions: Ice slurry ingestion before and between innings reduced thermal, cardiovascular, and perceptual strain. However, it did not affect softball pitching performance compared to cool fluid ingestion. [ABSTRACT FROM AUTHOR]

This study compared differences in pitching kinematics between normal-weight and overweight high school baseball pitchers. Twenty male pitchers were included in the study. According to the 2020 guidelines on the Body Mass Index (BMI) standard for children and adolescents by the Korean Society for the Study of Obesity, 10 participants with BMI below the 85% percentile were assigned to the normal-weight group, and 10 participants with BMI above the 85% percentile were assigned to the overweight group. The two groups threw 10 trials for a fastball with maximum effort. Out of 10 trials, three pitches thrown in the strike zone with the fastest velocity were extracted. The mean ball velocity was measured, and the mean and maximum angle and angular velocity of the knee, pelvis, trunk, shoulder, and elbow joints were calculated. The differences in the ball velocity, angle, and angular velocity between the two groups were compared using an independent t-test (p<0.05). There were no differences in mean ball velocity between the two groups. However, compared with the normal-weight group, the overweight group showed smaller knee flexion, trunk forward tilt, trunk rotation, maximum trunk angular velocity, shoulder external rotation and maximum shoulder external rotation, while shoulder abduction and maximum elbow flexion were greater. These results suggest that the overweight group may have a high risk of soft tissue damage in the knee, shoulder, and elbow joints caused by limited movement of the trunk and inefficient movement between the extremities during power pitching [ABSTRACT FROM AUTHOR]

Background: It has previously been speculated that baseball pitchers who display excessive forearm pronation at foot contact (FC) have a higher propensity toward ulnar collateral ligament injury and subsequent surgery. Purpose: To evaluate the association between degree of forearm pronation/supination at FC and throwing arm kinetics in high school and professional pitchers, at both the individual (intrapitcher) and the group (interpitcher) level. Study Design: Descriptive laboratory study. Methods: High school (n = 41) and professional (n = 196) pitchers threw 8 to 12 fastballs while being assessed with a 3-dimensional motion-capture system (480 Hz). Pitchers at each playing level were divided into a supination or pronation subgroup depending on degree of forearm pronation at FC. Regression models were built to observe the relationship between forearm pronation at FC and kinetic and kinematic parameters of interest. Results: At both the individual and the group level of high school and professional pitchers, there was no significant correlation between forearm pronation at FC and elbow varus torque (P min =.21). For every 10° increase in forearm pronation at FC in the individual high school pitcher, elbow flexion at FC decreased by 5°, whereas maximum elbow extension velocity was achieved 0.6% later in the pitch. In addition, elbow medial force increased by 4.1 N and elbow varus torque increased by 0.8 N·m for every 10° increase in forearm supination at FC. For every 10° increase in forearm supination in the individual professional pitcher, ball velocity increased by 0.5 m/s, shoulder external rotation at FC decreased by 11°, and elbow medial force decreased by 5.5 N. Conclusion: Supination- or pronation-predominant forearm motion during the pitch did not significantly differ between playing levels. Excessive forearm pronation at FC was not a significant risk factor for increased throwing arm kinetics for high school or professional pitchers. There was a weak positive association between forearm supination at FC and elbow varus torque in the individual high school pitcher. Ultimately, coaches and pitchers may be better served by redirecting their focus to other mechanical aspects of the pitch that may have stronger associations with injury risk implications as well as performance. [ABSTRACT FROM AUTHOR]

In overhead throwing, core muscles play a role in transferring momentum from the trunk to the arm. Yet, studies evaluating various core exercise programs on core muscle function and ball-throwing velocity yield varying results. The objective of this systematic review was to synthesize the effects of these programs on ball-throwing velocity and trunk muscle function based on the focus of the training program. Searches were conducted using MEDLINE on November 24, 2020, and updated on April 27, 2022. Articles were included if the training was administered to overhead-throwing athletes, targeted the core musculature, and had at least 1 comparison group. Of a total of 875 articles retrieved, 11 were selected for analysis. The synthesis of evidence suggests that (a) commonly used spinal stabilization exercises may improve trunk muscle endurance and isometric strength, but not ball-throwing velocity; (b) advanced spinal stabilization exercises performed on a sling suspension system can improve ball-throwing velocity; and (c) trunk plyometrics using medicine balls can improve trunk rotational strength, power, and ball-throwing velocity. More challenging core exercises that incorporate unstable surfaces, higher resistance, and dynamic trunk movement seem necessary to promote improvement in ball-throwing velocity. [ABSTRACT FROM AUTHOR]

Ball throwing velocity is essential for scoring goals in handball; the crucial question is how to develop throwing velocity in highly trained handball players. Therefore, this systematic review aims to summarize effective conditioning strategies to improve throwing velocity in elite male players and to perform a meta-analysis on which training system can provide the highest increase in throwing velocity. The literature was analyzed using the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) in PubMed, Scopus, and Web of Science. Thirteen studies (sample n = 174) were included: five resistance training studies, one core training study, one study on repeated shuffle sprint training with small-sided games, and one on eccentric overload training. Effect size comparison showed that resistance training is the most effective strategy for improving throwing velocity in elite handball players (d > 0.7). Core training showed a small effect (d = 0.35). Small-sided game (SSG) training showed different results, from a significant positive effect (d = 1.95) to a negative effect (d = -2.03), and eccentric overload training showed a negative effect (d = -0.15). Resistance training is the most effective strategy for improving throwing velocity in elite handball players, while core training and SSGs can improve throwing velocity in youth athletes. Due to the small number of studies focusing on elite handball players, there is a need for more studies on advanced resistance training methods, e.g., contrast, complex, ballistic training, because much greater demands are placed on handball performance assumptions. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the differences in golf swing execution in terms of the parameters of the pelvis and thorax movement between the sexes in junior golfers and their relation to the golf club velocity. Elite female and male players (age: 15.4 ± 1.0 and 15.8 ± 1.7 years, respectively) performed 10 golf swings with a driver under laboratory conditions. Pelvis and thorax movement parameters and golf club velocities were measured using a three-dimensional motion capture system. Statistical parametric mapping analysis of pelvis–thorax coupling revealed a significant difference (p < 0.05) between boys and girls during backswing. Analysis of variance showed a significant effect of sex on the parameters of maximal pelvic rotation (F = 6.28, p = 0.02), X-factor (F = 5.41, p = 0.03), and golf club velocity (F = 31.98, p < 0.01). No significant relationship was found between pelvis and thorax movement parameters and golf club velocity in the girls. We found a significant negative relationship between the parameters of maximal thorax rotation and golf club velocity (r = −0.941, p < 0.01) and between X-Factor and golf club velocity (r = −0.847, p < 0.05) in the boys. We suggest that these negative relationships in males were caused by the influence of hormones during their maturation and biological development, where there is decreased flexibility (lower shoulders rotation and X-factor) and growth of muscle strength (higher club head velocity). [ABSTRACT FROM AUTHOR]

Aim: To analyse the validity of the mobile application (Athla Velocity) used to measure ball speed. Method: A total of 67 volunteer male tennis players with a mean age of 24.94 ± 4.91 years participated in the study. In all measurements, the successful 10 service strike velocity made by the athletes in the determined area were evaluated. Each service strike was measured concurrently using both the Stalker Solo 2 radar device and the Athla Velocity application. Bland-Altman and regression analyses were used to determine the validity. Results: A high positive correlation was found between the radar device and Athla Velocity Application measurements (ICC = 0.970, r2 = .989). In addition, according to the Bland-Altman analysis, the measurement results of the two methods were found to be within the calculated limited area to a large extent. Conclusion: It has been determined that the Athla Velocity application can measure 98% close to the Stalker Pro 2 device in ball velocity measurement. As a result, it can be said that the Athla Velocity application can be used validly in ball velocity measurements.

In this study the effect of level of opposition on throwing performance and coping strategies in the jump throw was examined in elite, amateur, and adolescent players in team handball. Twenty four participants consisting of 13 female elite junior handball players (age: 15.5 ± 0.7 years; height: 1.72 ± 0.07 m; body mass: 64.2 ± 7.0 kg; years of handball experience: 8.4 ± 1.76 years) and 11 senior recreational female handball players (age: 19.5 ± 1.04 years; height: 1.68 ± 0.08 m; body mass: 65.2 ± 9.3 kg; years of handball experience: 11 ± 2.61 years) performed ten jump throws under four conditions: (1) without opposition; (2) with a passive opponent; (3) with an opponent moving sideways; and (4) with a defender who was instructed to be unpredictable without physical contact with the thrower. Ball velocity and accuracy were measured for every throw together with answering a questionnaire consisting of 18 questions after each condition to investigate if coping strategies changed with increasing difficulty of task and if this was different for playing level. The main findings were that ball velocity and accuracy decreased when opposition was introduced, but with no differences when the opposition moved only sideways or unpredictably (forwards and/or sideways), similarly for both groups. Furthermore, the level had no influence on the coping strategies or a relationship with either of these coping strategies, but the avoidance coping strategy scored lower than the other two categories for both groups. It was concluded that level of opposition had a negative effect on throwing velocity and accuracy in elite junior and recreational level senior players which was probably caused by the change of given attention to one target (overcome opponent), which leaves less available for others (throwing velocity and accuracy). Furthermore, coping strategies did not change or have any correlation with throwing performance, indicating that these strategies seem to be influenced by trait and that most players mainly used problem- and emotional-focused coping strategies and less avoidance strategies when dealing with the level of opposition.

Excessive elbow valgus stress can often cause pitching elbow injuries, and rehabilitation is usually required before an athlete can resume playing. However, there is a lack of information on the partial load rehabilitation of pitching elbow injuries caused by valgus extension overload based on elbow valgus stress. The purpose of this study was to clarify how quantitative partial elbow valgus stress while pitching affects ball velocity and subjective pitch-effort. Forty-six male baseball pitchers participated in this study. Each player wore a wearable device on the elbow that collected their pitch parameters. Ball velocity was measured using a radar gun. Each elbow valgus stress was measured while each player was instructed to throw 5 fastballs at full effort. Then, based on the average stress of the 5 throws (100% partial valgus stress), the 75% and 50% stresses were calculated (75% and 50% partial valgus stress, respectively). Each pitcher continued to pitch until the number of pitches thrown at the targeted elbow stress reached 5. Each player was asked about their subjective pitch-effort after completing each type of partial valgus stress pitch. Outcomes were statistically evaluated using either a 1-way repeated measures analysis of variance or 2-way analysis of variance. The ball velocity was 72% (95% confidence interval [CI], 69%-75%) and 58% (95% CI, 55%-61%) during the 75% and 50% partial valgus stress, respectively (P <.001). Subjective pitch-effort was 41% (95% CI, 38%-44%) and 19% (95% CI, 16%-22%) while pitching at 75% and 50% partial valgus stress, respectively (P <.001). It may be desirable to instruct pitchers to throw at less than 20% subjective pitch-effort of the max if they want to pitch at 50% partial valgus stress. Elbow valgus stress might correlate with ball velocity at 75% partial valgus stress pitch. These results could enable clinicians and coaches to perform safer return-to-throwing programs and prevent excessive load on the elbow. [ABSTRACT FROM AUTHOR]

OBJECTIVES This study examined the effects of clubbell exercises in a pitcher training program on the range of motion (ROM), muscle function, and its subsequent influence on pitching velocity. Additionally, this study aimed to develop an optimal training program to prevent injury while improving pitcher performance. METHODS Eighteen pitchers were included and equally divided into clubbell exercise and control groups. Clubbell training was conducted through 60-minute sessions twice a week for 12 weeks. Internal/external rotational (IR/ER) ROM, IR/ER muscle strength, muscle endurance, muscle power, and pitching velocity were measured before and after the intervention. RESULTS The IR (p = 0.051) and total ROM (TROM; p = 0.05) of the throwing arm decreased in the control group but increased in the clubbell exercise group, with an observed tendency of interaction. In the non-throwing arm, the ER ROM was significantly different between the two groups (p

The aim of this study was to discriminate the effect of five increases of 15% in the mass of the ball on the most significant kinematic variables that determine the throwing performance. The sample was comprised of twelve male players specializing in front-line throws and belonging to the Spanish Asobal Handball League. Every throw was recorded by two video cameras temporally synchronized at 250 Hz, which allowed us to obtain the spatial coordinates of a model made up of five body markers and the geometric center of the ball. From these coordinates, the components of the positions and linear velocity of the ball were determined, in addiction, the angular positions and velocities of vertical rotation of the upper trunk, shoulder flexion, external / internal rotation of the shoulder, and flexion / extension of the elbow were also obtained. The results indicate that the velocity of the ball decreases with the increase in the mass of the ball and the angular velocity of internal rotation of the shoulder is the most affected factor, followed by the extension of the elbow. The throwing time increases when the mass of the ball increases due to the longer backward movement time of the ball. It is estimated that a 15% increase in the ball mass has no effect on the kinematics of the throw.

Simple Summary: Goalball is a dynamic sport for visually impaired people, where attack and defense situations alternate during the game. In attack situations, the throwing performance could be dependent on several variables such as the anthropometry, the core stability, or the balance of the athletes. In defense situations, the reaction time to an acoustic stimulus could be also considered as a performance factor. All these variables have been analyzed in this pilot study assessing the ball velocity and accuracy in throwing, analyzing the relationship with the previous parameters. New evaluation tests have been proposed in this research, suggesting a more specific evaluation test battery for this sport. Goalball is a sport for visually impaired athletes, where the roles of attack and defense change continuously during the game. Performance evaluation should consider the variables that determine the throwing and the stop and clearance of the ball. The aim of this study is to evaluate the precision and velocity of the ball throwing in goalball, besides core stability and balance as variables that determine an optimal throwing. Moreover, a novel acoustic reaction time is applied to analyze the defense performance. Eight goalball players (33 ± 9 years old; 77.8 ± 22.7 kg; 174 ± 13 cm; 10 ± 5 years of experience) were recruited to assess ball velocity, with a radar gun, and throwing accuracy. Anthropometry, static balance, and core stability were assessed using a computerized pressure platform. Acoustic reaction time was measured with a photoelectric system. A significant positive correlation was found between throwing speed and the years of experience (Ƿ = 0.714, p = 0.047), height (Ƿ = 0.786, p = 0.021), dominant leg surface area of the stabilogram (Ƿ = 0.738, p = 0.037), and non-dominant leg center of pressure mean velocity (Ƿ = 0.714, p = 0.017). In the present pilot study, height and years of experience are correlated to throwing velocity. This is also the first test proposal to assess throwing precision and complex acoustic reaction in goalball players, which could be used to assess the level of performance in future studies. [ABSTRACT FROM AUTHOR]

The aim of this study is to analyze the relationship between ball velocity thrown from two different positions, parameters of upper body anthropometrics and hand grip strength as a marker of upper body strength. Twelve well-trained female handball players (age, 22.47±4.57 years; body mass, 66.70±11.05 kg; height, 167.33±7.41 cm; handball experience, 9.91±3.47 years), playing in a team that competes in the first division of the Handball League of Turkey joined this study. Body weight, height, body mass index (BMI), body fat percent and trunk muscle mass, hand length and breadth, sitting height, arm span index and dominant hand grip strength measured by using a stadiometer, bioelectric impedance device, anthropometric set, fiberglass measuring tape and hand grip dynamometer respectively. Ball velocity was measured with a speed radar for both throwing positions (throws are made from a sitting position either with a non-throwing hand on the floor (RP) or non-throwing arm free (RS). According to hierarchical multiple regression analysis carried out; the original contribution of fat percentage, trunk muscle mass, BMI and handgrip strength included in the model in the first step is not significant within the model and both RP and RS were not able to predict ball velocity (p gt;0.05). It was also determined that hand length, hand breadth, sitting height and arm span index which were included in the model in the second step were not significant and did not predict the ball velocity for both RP and RS as well (p gt;0.05). However, there was a positive relationship between trunk muscle mass and ball velocity with RP (r = 0.831; p lt;0.05). No relationship was found between other variables and ball velocity for both RP and RS. According to the results of the study, handball players and their coaches might consider designing resistance training programs that put an emphasis on increasing trunk muscle mass to increase the ball velocity during over arm throws.

The purpose of this study was to measure the effect of body size, gender, and their interaction on the ball velocity of the drag-flick performance of Pakistani elite field hockey players. Sixteen elite players (male=8, female=8) from recognized National Hockey Clubs were selected and their drag flick performance was recorded through the VICON motion capturing system. Descriptive statistics, general linear model (univariate), and factor analysis were used for statistical analysis. The average ball velocities of the male and female players were 21.31±3.20 m/s and 15.01±3.75 m/s, respectively. The body size explained 22.4% and gender explained 52.5% variability in the ball velocity of the drag-flick. The gender, body size, and their interaction had a significant (p<0.05) effect on the ball velocity. It was concluded that gender had a significant effect on the ball velocity even after controlling the effect of body size. Players should synchronize their body size in an optimum way to attain high ball velocity in drag-flick performance. [ABSTRACT FROM AUTHOR]

Background: The relationships between shoulder abduction and external rotation with peak kinetic values at the shoulder and elbow in professional baseball pitchers are not well established. Methods: Professional pitchers (n = 322) threw 8–12 fastballs under 3D motion analysis (480 Hz). Pitchers were stratified into quartiles by shoulder abduction and external rotation at distinct timepoints. Regression analyses were performed to quantify associations between shoulder position and kinetics. Results: Shoulder abduction remained relatively consistent throughout the pitch (foot contact–ball release: 85.5 ± 11.1–90.7 ± 8.4°); shoulder external rotation increased dramatically (foot contact–ball release: 30.8 ± 24.6–165.2 ± 9.7°). For every 10° increase in maximum shoulder rotation, shoulder superior force increased by 2.3% body weight (p < 0.01), shoulder distraction force increased by 5.9% body weight (p < 0.01), and ball velocity increased by 0.60 m/s (p < 0.01). Shoulder abduction was significantly associated with shoulder superior force at all timepoints but not with ball velocity (p > 0.05). For every 10° increase in shoulder abduction at ball release, shoulder superior force increased by 3.7% body weight (p < 0.01) and shoulder distraction force increased by 11.7% body weight (p < 0.01). Conclusion: Increased shoulder abduction at ball release and increased maximum shoulder external rotation were associated with greater superior and distraction forces in the shoulder. Pitchers can consider decreasing shoulder abduction at later stages of the pitch to around 80° in order to minimize shoulder superior force, with no impact on ball velocity. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the differences in golf swing execution in terms of the parameters of the pelvis and thorax movement between the sexes in junior golfers and their relation to the golf club velocity. Elite female and male players (age: 15.4 ± 1.0 and 15.8 ± 1.7 years, respectively) performed 10 golf swings with a driver under laboratory conditions. Pelvis and thorax movement parameters and golf club velocities were measured using a three-dimensional motion capture system. Statistical parametric mapping analysis of pelvis–thorax coupling revealed a significant difference (p < 0.05) between boys and girls during backswing. Analysis of variance showed a significant effect of sex on the parameters of maximal pelvic rotation (F = 6.28, p = 0.02), X-factor (F = 5.41, p = 0.03), and golf club velocity (F = 31.98, p < 0.01). No significant relationship was found between pelvis and thorax movement parameters and golf club velocity in the girls. We found a significant negative relationship between the parameters of maximal thorax rotation and golf club velocity (r = −0.941, p < 0.01) and between X-Factor and golf club velocity (r = −0.847, p < 0.05) in the boys. We suggest that these negative relationships in males were caused by the influence of hormones during their maturation and biological development, where there is decreased flexibility (lower shoulders rotation and X-factor) and growth of muscle strength (higher club head velocity).

Problem Statement: The drag-flick performance can be improved by understanding the effect of kinematic and anthropometric factors on the ball velocity of the drag-flick shot in field hockey. Purpose: The purpose of this study was to identify the association and influence of the selected kinematic and anthropometric factors on the ball velocity of the drag-flick in field hockey. Methods: The kinematic factors of 64 drag-flicks of 16 (female = 8, male = 8) national elite hockey players were measured through 3D biomechanical analysis using VICON motion capturing system and MATLAB software. Pearson correlation and regression analysis were used for statistical analysis. Results: The ball velocity had significant correlation with drag length (r = 0.70, p < 0.01), drag time (r = 0.29, p < 0.05), drag velocity (r = 0.59, p < 0.01), stance width (r = 0.53, p < 0.01), average right knee angle (r = -0.36, p < 0.01), average left elbow angle (r = -0.31, p < 0.05), age (r = -0.32, p < 0.05), weight (r = 0.36, p < 0.01), and height (r = 0.39, p < 0.01). Drag length (β1 = 4.63), stance width (β2 = 8.19), average right knee angle (β3 = -0.07), age (β4 = -1.62), and height (β5 = 0.15) had significant (p < 0.05) influence on the ball velocity of the drag-flick. Conclusion: To make a drag-flick with high ball velocity, the players maximize their ball drag length and stance width while minimizing their average right knee angle. In addition, the players' height had a significant and positive contribution towards the ball velocity. The coaches should focus on the drag length and stance width of the flickers to increase their performance. [ABSTRACT FROM AUTHOR]

BACKGROUND Despite increased awareness of factors related to athletic performance and injury prevention, youth and adolescent baseball players continue to report injuries at alarming rates. Upper extremity muscle strength is an integral part of physical assessment and injury prevention in baseball players, however minimal data exists in youth populations. Changes in anthropometric measures, inherent in physically developing athletes, have been shown to impact strength measures, however normalization methodology is rarely reported. PURPOSE The purposes of this study were to 1) compare the measurement properties of five potential methods for normalizing isometric shoulder strength in a cohort of 9-12 year old male baseball players and 2) examine the relationship between normalized isometric shoulder strength and ball velocity in a cohort of 9-12 year old male baseball players. STUDY DESIGN Prospective cohort study (n=159) METHODS Baseline and follow up height, weight and bilateral ulnar length measurements were assessed followed by isometric strength in both the dominant and non-dominant shoulders. Strength measures included scapular plane abduction (scaption), external rotation (ER) at 0°, ER and internal rotation (IR) at 90°. Ball velocity was assessed as a measure of throwing performance. Intraclass correlation coefficients (ICC2,1), standard errors of measurement (SEM) and minimal detectable change (MDC95) were calculated for all strength measures. Repeated measures ANOVA were conducted comparing changes in normalized strength using five separate anthropometric measures: weight, height, body mass index, ulnar length and % of non-dominant shoulder strength. Linear regression models were used to examine the relationships between normalized isometric shoulder strength and ball velocity. Statistical significance was set a priori at a =0.05. RESULTS Shoulder strength normalized using ulnar length was the only method that demonstrated excellent reliability (ICC2,1 0.98-0.99) and detected significant changes between strength in each of the four measures tested (SEM 0.39-0.69 Nm). Modest but significant correlations were observed between scaption and ball velocity (r2 = 0.27, p < 0.001) and ER at 0° and ball velocity (r2 = 0.23, p < 0.001). CONCLUSION Ulnar length was the most stable and reliable normalization method for assessing isometric shoulder strength in youth baseball players. In addition, normalized scaption strength was the most significant predictor of ball velocity, followed by ER at 0° strength in this population. [ABSTRACT FROM AUTHOR]

Shooting velocity is one of the most important features that influence successful shooting performance in handball. Therefore, the aim of this study was to determine differences in shooting velocity between shooting positions in top level handball. A total of 784 shots were analyzed. Shooting velocity was measured with iBall (SELECT, Denmark), that has a built-in chip for tracking and distributing data in real time regarding ball velocity, shot detection, shot position and the position of the ball in the goal (Kinexon, Germany). Shooting position (SP) is defined as a geometrical point and a tactical situation from which a shot was taken. Differences between shooting positions were calculated using the Kruskal-Wallis test. Significant difference in shooting velocity was noticed between shooting positions (Chi-Square=95.83). Post-hoc analysis revealed that shots executed outside the nine meter perimeter are significantly faster than from other shooting positions. Shots taken outside the 9-meter perimeter require the fastest shots since players cannot outsmart goalkeepers with modified slow shots (e.g. lob shot, shot with rotation or "dry leaf" shot). Modified slow shots are commonly used in closer distance shots like wing shot, fast break shot, breakthrough shot or penalty shot. In these situations, players have more demanding angle in which shooting velocity is not always an advantage.

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Supplemental Digital Content is Available in the Text. Müller, C and Zentgraf, K. Neck and trunk strength training to mitigate head acceleration in youth soccer players. J Strength Cond Res 35(12S): S81–S89, 2021—Heading in soccer involves repetitive head accelerations that may be detrimental for brain health. One way to mitigate adverse effects may be to increase head-neck stabilization and thus reduce the kinematic response after intentional headers. This study aimed to (a) assess associations between neck strength and head kinematics and (b) evaluate an exercise intervention designed to increase strength and attenuate head acceleration during intentional heading in youth soccer players. In 22 athletes, we used accelerometers to assess associations between neck strength and peak linear acceleration (PLA). We attached the accelerometers to the occiput and sternum, allowing us to differentiate between total, trunk, and head PLA. Longitudinally, we evaluated the effects of a 14-week twice-weekly resistance training in a subsample of 14 athletes compared with regular soccer training (N = 13). Results showed that female athletes had lower isolated neck strength (p ≤ 0.004), lower functional neck strength (p ≤ 0.017), and higher total PLA during purposeful headers compared with males (17.2 ± 3.5 g and 13.0 ± 2.3 g , respectively, at 9.6 m·s−1 ball velocity during impact; p = 0.003). The intervention group showed moderate to large strength gains ( η p 2 = 0.16–0.42), resulting in lower PLA (total −2.4 g , trunk −0.8 g , and head −1.5 g) during headers. We conclude that a resistance training focusing on cervical and trunk musculature is practicable in youth soccer, elicits strength gains, and helps to mitigate PLA during purposeful heading. Results should encourage youth strength and conditioning professionals to incorporate neck exercises as a risk reduction strategy into their training routine. [ABSTRACT FROM AUTHOR]

Supplemental Digital Content is Available in the Text. Sorbie GG, Glen J, and Richardson AK Positive relationships between golf performance variables and upper body power capabilities. J Strength Cond Res 35(12S): S97–S102, 2021—The importance of lower body and trunk strength and power, as well as upper body strength in golf is well documented; however, the relationship between upper body power and golf performance has yet to be determined. Therefore, the purpose of the study was to investigate the relationships between golf performance and upper body power. Thirteen golfers (mean ± SD : age: 30 ± 7 years and handicap: 6.1 ± 4.9) participated in the study. Club head velocity (CHV) and ball velocity were measured during the golf test. To assess upper body power, subjects completed a ballistic bench press and upper body Wingate test. Pearson product-moment correlations were used to assess the relationships between golf performance and upper body power. The results demonstrated that there were strong relationships between ballistic bench press and CHV and ball velocity when using the driver (r > 0.6–0.7), and moderate-to-strong relationships (r > 0.4–0.6) when using the 7-iron. Strong relationships were found between the upper body Wingate test and CHV and ball velocity (r > 0.5–0.8) when using the driver and 7-iron. As a result of the findings, strength and conditioning coaches may use both the ballistic bench press test and the Wingate test as a primary assessment to measure the effectiveness of upper body training interventions with the aim of improving golf performance. Although, when performing the golf swings at higher velocities (i.e., with the driver), the ballistic bench press may be more beneficial. [ABSTRACT FROM AUTHOR]

Goalball is a sport for visually impaired athletes, where the roles of attack and defense change continuously during the game. Performance evaluation should consider the variables that determine the throwing and the stop and clearance of the ball. The aim of this study is to evaluate the precision and velocity of the ball throwing in goalball, besides core stability and balance as variables that determine an optimal throwing. Moreover, a novel acoustic reaction time is applied to analyze the defense performance. Eight goalball players (33 ± 9 years old; 77.8 ± 22.7 kg; 174 ± 13 cm; 10 ± 5 years of experience) were recruited to assess ball velocity, with a radar gun, and throwing accuracy. Anthropometry, static balance, and core stability were assessed using a computerized pressure platform. Acoustic reaction time was measured with a photoelectric system. A significant positive correlation was found between throwing speed and the years of experience (Ƿ = 0.714, p = 0.047), height (Ƿ = 0.786, p = 0.021), dominant leg surface area of the stabilogram (Ƿ = 0.738, p = 0.037), and non-dominant leg center of pressure mean velocity (Ƿ = 0.714, p = 0.017). In the present pilot study, height and years of experience are correlated to throwing velocity. This is also the first test proposal to assess throwing precision and complex acoustic reaction in goalball players, which could be used to assess the level of performance in future studies.

The purpose of this study was to investigate the effect on throwing performance (velocity and accuracy) of experienced female handball players when throwing at four different targets in a handball goal. Thirteen experienced female handball players (age 18.2 ± 1.7 years, height 1.7 ± 0.10 m, mass 68.1 ± 19.6 kg, and training experience 9.5 ± 3.7 years) performed 10 throws from a 7 m distance at each corner of the handball goal with maximal effort. Maximal ball velocity was recorded with a radar gun together with mean radial error, centroid error, and bivariate variable error, as measurements of accuracy. The main findings were that the ball velocity was higher when throwing at targets at the ipsilateral side, compared with the contralateral side, while throwing consistency (bivariate variable error) decreased when throwing at the contralateral side upper corner. No velocity-accuracy trade-off was found between the four targets. Based upon the findings, it is suggested that players throw to the (upper) ipsilateral side of the goal when performing a penalty throw, dependent on the goalkeepers’ position, since the ball velocity is the highest here, without losing accuracy. This gives the goalkeeper less time to react and stop the ball, thereby giving the player the highest chance of scoring.

This study aimed to identify the effects of different kick types on the relationship between kicking leg muscle activation and ball velocity. The muscle activation of selected knee extensor and flexor muscles of 10 amateur soccer players were measured using electromyography during the performance of six maximal soccer kick types. The highest ball velocity was achieved by the instep kick (96.2 km/hr-1), followed by the lofted kick, the inside curve kick, the outside kick, the outside curve kick, and finally the inside kick (81.3 km/hr-1). There were significant positive correlations between muscle activation and ball velocity for the vastus lateralis and lofted (0.765), inside curve (0.792) and instep kicks (0.788), and for the gastrocnemious with the outside kick (0.796). Non-significant correlations between muscle activation and ball velocity exhibited a trend such that they were positive for the vastus medialis and vastus lateralis but negative for the biceps femoris and gastrocnemious for inside-foot-dominated kicks, while this trend was reversed for outside-foot-dominated kicks. According to results, the noted trends can be explained by the change in muscle activation patterns required to orientate the foot for each type of kick; this has implications for players’ training activities.

Ball velocity is considered an important performance measure in baseball pitching. Proper pitching mechanics play an important role in both maximising ball velocity and injury-free participation of baseball pitchers. However, an individual pitcher’s characteristics display individuality and may contribute to velocity imparted to the ball. The aim of this study is to predict ball velocity in baseball pitching, such that prediction is tailored to the individual pitcher, and to investigate the added value of the individuality to predictive performance. Twenty-five youth baseball pitchers, members of a national youth baseball team and six baseball academies in The Netherlands, performed ten baseball pitches with maximal effort. The angular velocity of pelvis and trunk were measured with IMU sensors placed on pelvis and sternum, while the ball velocity was measured with a radar gun. We develop three Bayesian regression models with different predictors which were subsequently evaluated based on predictive performance. We found that pitcher’s height adds value to ball velocity prediction based on body segment rotation. The developed method provides a feasible and affordable method for ball velocity prediction in baseball pitching.

The purpose of this study was to investigate a baseball catcher's throwing time to second base using three throwing motion types. The subjects were professional (n = 4) and college (n = 12) baseball catchers. Two high-speed cameras were set to capture the throwing motion, while one was set to capture the net on second base. The throwing time of quick throw (throwing motion to release the ball immediately after catching the ball rather than usual throwing motion) was significantly shorter than those of usual throw (throwing motion used during games and practice) and fast ball throw (throwing motion to increase the ball velocity than usual throwing motion). From this result, it became clear that quick throw is the optimal throwing motion when judged by time. Thus, with respect to correlations between variables, there were significant positive correlations between throwing and motion times (usual throw: r = 0.760; fast ball throw: r = 0.719; quick throw: r = 0.767), and between throwing and airborne times (usual throw: r = 0.784; fast ball throw: r = 0.744; quick throw: r = 0.806), for all three throwing motions. However, negative correlations were shown between throwing and release times in usual throw and fast ball throw. The results suggest that, to shorten the throwing time, it is necessary to shorten the hold and stride times and to improve the ability to throw the ball as fast as possible with a shorter motion time. [ABSTRACT FROM AUTHOR]

The objectives of this study were: (i) to analyse anthropometric parameters, physical fitness, and throwing velocity of youth elite male handball players of different ages; and (ii) to develop a multivariate model that explains throwing velocity. Fifty-three male handball players (17.99±1.68 years old), members of the Icelandic national teams, participated in the study. The participants were classified into the U21 (n=12), U19 (n=17), and U17 (n=24) national teams. All were evaluated by basic anthropometry (body height, body mass, body mass index), physical fitness tests (counter movement jump, medicine ball throw, hand dynamometry, 10 m and 30 m sprint, Yo-Yo IR2 test) and ball velocity after various handball throws at goal (a 7-m throw, a 9-m ground shot after a three-step run-up, and a 9-m jump shot after a three-step approach). A one-way analysis of variance with a Bonferroni post-hoc test was used to establish the differences between the teams. Multiple linear regression was used to predict speed of the ball from each of the three shots taken for each team. There were no differences between the U21 and U19 teams except for the medicine ball throw, but the U19 team scored better than the U17 team in almost all variables. Ball speed after a handball shot was predicted (between 22% and 70% of accuracy) with only one or two physical fitness variables in each model medicine ball throw (in four models), counter movement jump (in two models), and 10 m sprint (in two models), being the variables that were most selective. [ABSTRACT FROM AUTHOR]

Although it is well established that velocity of execution is an important performance factor in ball sports and the presence of opposition influences it, there has been no research done to date on ball velocity in padel shots. The overhead smash is one of the most successful shots in this sport, and the present study aimed to study the effect of opposition on smash performance in semi-professional and amateur padel players. Forty-four semi-professional (n=14) and amateur (n=30) players volunteered to participate in this study. The overhead smash velocity was recorded for both groups of players with and without opposition using a radar gun. Ball velocity decreased in both groups of players in the presence of opposition (from 133.1±8.2 km·h-1 to 120.72±9.8 km·h-1 in semi-professional players; and from 124.6±9.2 km·h-1 to 104.5±10.0 km·h-1 in amateurs, p<.001). Although the semi-professional players achieved a greater velocity in both situations (p<.001) compared to amateurs, the reduction of velocity in the presence of opposition was greater in the amateurs (p<.001). The greater velocities for the semi-professional padel players could be attributed to a technical and tactical superiority due to their greater experience and higher level of competition. Simulating conditions of opposition could help reduce the velocity-precision trade-off, helping the players increase their overhead smash velocities. [ABSTRACT FROM AUTHOR]

Six university soccer players were selected for a correlational and comparative study. The correlation between squat jump height and 10-metre sprints, 30-metre sprints, arrowhead agility test, static balance test and velocity ofball during instep kickwereinvestigated. The comparative study involved comparisons between ball velocityandbetween the muscle activity of vastus lateralis, rectus femoris, biceps femoris and tibialis anterior of kicking limb and supporting limbduring instep soccer kick from 0-degree, 45-degree and 60-degree angle of approach from the target with the dominant limb and non-dominant limb. A significant association was found between squat jump height and 10-metre sprints (r = -0.93, p = 0.007) and 30-metre sprints (r = -0.88, p = 0.021). Also, significantly greater ball velocities were attained from 45-degree angle of approach with the dominant limb(= 7.49, p = 0.010, partial 37.50, p = 0.002, partial = 0.88). Greater muscle activity was found in tibialis anterior of kicking limb(= = 0.60)as well as non-dominant limb(= 6.52, p = 0.015, partial = 0.57) when the dominant limbwas used for instep kick and in rectus femoris of supporting limb(= 5.536, p = 0.024, partial = 0.52) when non-dominant limbwas used from 0-degree approach. [ABSTRACT FROM AUTHOR]

Background: The variability of throwing metrics, particularly elbow torque and ball velocity, during structured long-toss programs is unknown.Hypotheses: (1) Elbow torque and ball velocity would increase as throwers progressed through a structured long-toss program and (2) intrathrower reliability would be high while interthrower reliability would be variable.Study Design: Descriptive laboratory study.Level Of Evidence: Level 3.Methods: Sixty healthy high school and collegiate pitchers participated in a structured long-toss program while wearing a validated inertial measurement unit, which measured arm slot, arm velocity, shoulder rotation, and elbow varus torque. Ball velocity was assessed by radar gun. These metrics were compared within and between all pitchers at 90, 120, 150, and 180 ft and maximum effort mound pitching. Intra- and interthrower reliabilities were calculated for each metric at every stage of the program.Results: Ball velocity significantly changed at each progressive throwing distance, but elbow torque did not. Pitching from the mound did not place more torque on the elbow than long-toss throwing from 120 ft and beyond. Intrathrower reliability was excellent (intraclass correlation coefficient >0.75) throughout the progressive long-toss program, especially on the mound. Ninety-one percent of throwers had acceptable interthrower reliability (coefficient of variation <5%) for ball velocity, whereas only 79% of throwers had acceptable interthrower reliability for elbow torque.Conclusion: Based on trends in elbow torque, it may be practical to incorporate pitching from the mound earlier in the program (once a player is comfortable throwing from 120 ft). Ball velocity and elbow torque do not necessarily correlate with one another, so a degree of caution should be exercised when using radar guns to estimate elbow torque. Given the variability in elbow torque between throwers, some athletes would likely benefit from an individualized throwing program.Clinical Relevance: Increased ball velocity does not necessarily equate to increased elbow torque in long-toss. Some individuals would likely benefit from individualized long-toss programs for rehabilitation. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the kinematics in throwing with a regular weighted handball with 20% lighter and heavier balls in female experienced handball players. In total, eight joint movements during the throw were analyzed. The analysis consisted of maximal angles, angles at ball release, and maximal angular velocities of the joint movements and their timings during the throw. Results on 24 experienced female team handball players (mean age 18.2 ± 2.1 years) showed that the difference in ball weight affected the maximal ball velocity. The difference in ball release velocity was probably a result of the significant differences in kinematics of the major contributors to overarm throwing: elbow extension and internal rotation of the shoulder. These were altered when changing the ball weight, which resulted in differences in ball release velocity. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the contribution of upper extremity, trunk, and lower extremity movements in overarm throwing in team handball. In total, 11 joint movements during the throw were analyzed. The analysis consists of maximal angles, angles at ball release, and maximal angular velocities of the joint movements and their timing during the throw. Only the elbow angle (extension movement range) and the level of internal rotation velocity of the shoulder at ball release showed a significant relationship with the throwing performance. Also, a significant correlation was found for the timing of the maximal pelvis angle with ball velocity, indicating that better throwers started to rotate their pelvis forward earlier during the throw. No other significant correlations were found, indicating that the role of the trunk and lower limb are of minor importance for team handball players. [ABSTRACT FROM AUTHOR]

Background: During rehabilitation throwing programs, baseball players are commonly asked to throw at reduced levels of effort (ie, 50% effort, 75% effort, etc) to moderate stress to healing tissues. It is currently unknown how changes in players’ perceived exertion compares with changes in actual exertion during structured long-toss programs. Purpose: To determine whether decreased effort correlates with decreased throwing metrics, whether metrics decrease proportionally with reductions in perceived effort, and to quantify intrathrower variability. Study Design: Descriptive laboratory study. Methods: Sixty male high school and collegiate baseball pitchers participated in a structured throwing program. A motusBASEBALL sleeve was worn by all players, which measured elbow varus torque, arm velocity, arm slot, and shoulder rotation. Ball velocity was measured with a radar gun. Each pitcher threw 5 throws a distance of 120 ft with 3 efforts: maximum effort, 75% effort, and 50% effort. Throwing metrics were compared among the 3 levels of effort to see if each 25% decrease resulted in proportional decreases in elbow varus torque and ball velocity. Intrathrower variability was determined for each throwing metric at each degree of effort. Results: All throwing metrics decreased as players decreased their perceived effort (P < .001). However, these observed decreases were much smaller in magnitude than the decreases in perceived effort. During the 75% effort throws, elbow varus torque was only reduced to 93% of maximum and velocity dropped to 86% of maximum. Similarly, for the 50% effort throws, elbow varus torque remained 87% of max effort torque, while velocity remained 78% of max. Intrathrower reliability was considered excellent for most metrics (intraclass correlation coefficient, >0.75). Conclusion: For every 25% decrease in perceived effort, elbow varus torque only decreased 7% and velocity only decreased 11%. Thus, when players throw at what they perceive to be reduced effort, their actual throwing metrics do not decrease at the same rate as their perceived exertion. Clinical Relevance: Measured effort decreased with decreasing perceived effort, but these were not proportional. This has significant implications for physical therapists, physicians, trainers, coaches, and athletes to understand and monitor elbow stress during the rehabilitation process. [ABSTRACT FROM AUTHOR]

Objectives: Performance factors in the volleyball spike jump are well known for male players; however, technical-coordinative differences for female players are known only marginally. The objective of this study was to investigate the relationship between movement characteristics and female' spike jump performance and to identify the most relevant aspects of jump height and ball velocity.Design: Single group correlation and regression.Methods: Fifteen elite female volleyball players performed spike jumps by striking a stationary ball at maximal jump height. Data were collected via twelve MX13 Vicon cameras (250Hz), two AMTI force plates (2000Hz), and controlled via Visual3D software.Results: Ten out of 42 characteristics correlated with jump height and none of 22 correlated with ball velocity. A stepwise regression model (adjusted R2=0.82, p<0.001) predicted jump height based on orientation step length and maximal angular velocity of dominant knee extension. For ball velocity, stepwise regression analysis was not feasible; however, an alternative model yielded adjusted R2=0.55, p<0.01.Conclusions: Key aspects for jump height were (1) optimised approach and energy conversion, (2) wide dynamic arm swing allowing for a forceful countermovement and, thus, increased range of motion in lower limbs, and (3) large angular velocities in ankles and knees, especially on the dominant side. These aspects strongly determined jump height in females and should be included in technical and strength-related training. For ball velocity, upper body anthropometrics and angular joint velocities emerged as the most important criteria. The importance of specific joints may depend on variations in striking technique. [ABSTRACT FROM AUTHOR]

The relationship between dynamic postural control, functional mobility and team handball throwing performance, velocity and accuracy, is largely unknown. The hand reach star excursion balance test (HSEBT) is a full kinetic chain assessment tool of these factors. Specifically, L135 and R135 (extension) reaches elicit joint movement combinations similar to the cocking and acceleration phase, while the L45 and R45 (flexion) reaches elicit joint movement combinations similar to the follow-through. The purpose of this study was to determine if specific HSEBT reach measures correlate with team handball throwing performance. Eleven elite female team handball players (21.7 ± 1.8 years; 71.3 ± 9.6 kg; 1.75 ± 0.07 m) executed selected HSEBT reaches before performing five valid step-up overhead throws (1x1m target) from which throwing velocity (motion capture) and accuracy (mean radial error) were quantified. Significant relationships between HSEBT measures and mean radial error, but not throwing velocity were established. Specifically, extension composite scores (L135+R135) for the dominant (150.7 ± 17.4cm) and nondominant foot (148.1 ± 17.5 cm) were correlated with mean radial error (p < 0.05). Also, specific reaches on the dominant (L135: 87.4 ± 5.6 cm; R135: 63.4 ± 11.8 cm) and non-dominant (R135: 87.0 ± 6.1 cm) foot were correlated with throwing error (p < 0.05). The lack of significant findings to throwing velocity might be due to a ceiling effect of both L135 and R135 and of throwing velocity. We conclude that while there may be other reasons for handball players to train and test functional mobility and dynamic postural control as measured in the HSEBT, no beneficial effect on throwing performance should be expected in an elite group of handball players. [ABSTRACT FROM AUTHOR]

Kicking ability in soccer has been evaluated predominantly by the maximum ball velocity. The kicking deficit (KD) may be defined as the percentage of the difference between the maximum ball velocity each player achieved by the non-preferred leg kick in relation to the preferred leg kick. This study aimed to compare: side-to-side kicking velocity, vertical jumps and anthropometrics between the younger (G-14) and older (G+14) than 14 years soccer players. An additional aim was to investigate associations among these variables. Participants were 92 young elite soccer players from the development programme of a top Spanish division club. They were divided into two age groups according to their growth and motor development stages (10.80-13.55 years, n=46; 14.02-16.39 years, n=46). Student's t-test showed that the maximum kicking velocity with the preferred and non-preferred leg, jumping performance, and all anthropometric measurements were significantly (p<.01) higher in G+14 compared with G-14. In contrast, KD values remained stable (15.31%-15.83%) without significant differences between the groups. Pearson's correlation analysis revealed that vertical jump tests and anthropometric measurements correlated with kicking ball velocity produced by the preferred and non-preferred leg. Our results demonstrate that kicking skills are still not consolidated and power factors may be determinant for kicking performance in young soccer players. In addition, the KD may be a constant element for both the under and above 14 years soccer players and could result from an unequal and greater use of the preferred leg in comparison with the non-preferred leg. [ABSTRACT FROM AUTHOR]