Pitch Type Research Articles

Setting final target score in T-20 cricket match by the team batting first

The purpose of this paper is to develop a deterministic model for setting the target in T-20 Cricket by the team batting first. Mathematical tools were used in model development. Recursive function and secondary data statistics of T-20 cash rich cricket tournament Indian Premier League (IPL) such as runs scored in different stages, fall wickets in different stages, and type of pitch are used in developing the model. This model was tested at 120 matches held IPL 2016 and 2017. This model had been proved effective by comparing with the models developed earlier. This model can be a useful tool to the stakeholders like coach and captain of the team for adopting better strategy at any stage of the match. For future research, this model can be useful in framing a regulation work by policy makers at both national and international cricket board by deriving the target score during interruptions.

Predictors of elbow torque among professional baseball pitchers

Overuse injuries of the shoulder and elbow continue to be prevalent in elite baseball pitchers. Pitch velocity has been shown to impact medial elbow torque in adolescent baseball pitchers. However, the determinants of medial elbow torque in professional baseball pitchers are not known. To determine the influence of pitch type, velocity, and player characteristics on medial elbow torque in professional baseball pitchers. Professional baseball pitchers were recruited for participation. Height, weight, body mass index (BMI), and throwing arm measurements were obtained for all study participants. While wearing a gyroscopic sensor equipped with an accelerometer, participants were instructed to throw a standard, randomized sequence of fastballs, changeups, and curveballs. Elbow torque, arm slot, arm speed, shoulder rotation, and ball velocity were recorded for each pitch. A linear mixed model was used to evaluate the association of pitch type with each pitch parameter, adjusting for pitchers' demographics. A total of 12 professional baseball pitchers were included in this study. Among the pitch types, medial elbow torque was significantly higher in fastballs than in curveballs (P = .001). An increased BMI value was independently associated with decreased elbow torque in pitchers (P = .035). Fastballs place significantly higher torque on the medial elbow than do curveballs, which is consistent with previous studies done on high school and collegiate populations. Pitchers with a higher BMI experience significantly less torque across the medial elbow.

Effects of Batting Practice and Visual Training Focused on Pitch Type and Speed on Batting Ability and Visual Function.

This study aimed to examine the effects of batting practice and visual training focused on the pitch type and speed on batting ability and visual function. A total of 46 participants took part in 12 training sessions for 4 weeks. The participants were divided into six groups according to the training type as follows: Group 1, batting practice with a fastball at 100 km/h; Group 2, tracking (watching) a fastball at 100 km/h; Group 3, batting practice with a fastball at 115 km/h; Group 4, tracking a fastball at 115 km/h; Group 5, batting practice with a curve ball at 100 km/h; and Group 6, tracking a curve ball at 100 km/h. Dynamic visual acuity, depth perception, hand-eye coordination, and batting ability were measured before and after training. Group 1 showed significant improvement in batting ability in the tests with 100 km/h fastballs and curve balls, while Groups 3 and 5 showed significant improvement in batting ability with 100 km/h fastballs and curve balls, respectively. Group 6 also showed significant improvement in batting ability with 100 km/h fastballs. Moreover, Groups 2 and 4 showed significant improvement in Dynamic visual acuity and hand-eye coordination, respectively. The results of the present study suggest that batting practice and visual training improve batting ability for the same pitch types and speeds as those encountered in practice. Therefore, visual training may be an effective method for improving batting ability and visual function in coaching settings.

Acoustic Pornography Recognition using Fused Pitch and Mel-Frequency Cepstrum Coefficients

The main objective of this paper is pornography recognition using audio features. Unlike most of the previous attempts, which have concentrated on the visual content of pornography images or videos, we propose to take advantage of sounds. Using sounds is particularly important in cases in which the visual features are not adequately informative of the contents (e.g., cluttered scenes, dark scenes, scenes with a covered body). To this end, our hypothesis is grounded in the assumption that scenes with pornographic content encompass audios with features specific to those scenes; these sounds can be in the form of speech or voice. More specifically, we propose to extract two types of features, (I) pitch and (II) mel-frequency cepstrum coefficients (MFCC), in order to train five different variations of the k-nearest neighbor (KNN) supervised classification models based on the fusion of these features. Later, the correctness of our hypothesis was investigated by conducting a set of evaluations based on a porno-sound dataset created based on an existing pornography video dataset. The experimental results confirm the feasibility of the proposed acoustic-driven approach by demonstrating an accuracy of 88.40%, an F-score of 85.20%, and an area under the curve (AUC) of 95% in the task of pornography recognition.

Examining environmental constraints in sport: Spin characteristics of two cricket pitches with contrasting soil properties

In the sport of cricket, the pitch is an organic surface that represents an important environmental constraint. While the soil properties of the pitch are known to influence the pace and bounce of medium and fast deliveries, it is unknown how the soil constructs or the seam of the cricket ball affect the pace, bounce, and deviation of a spinning delivery. A specialised spin bowling machine was used to deliver 276 (139 wrist spin, 137 finger spin) spinning deliveries onto two cricket pitches with contrasting soil properties. The pitches included a bespoke international pitch (BIP; higher sand content at 43.28%) and a common Australian pitch (CAP; lower sand content at 7.44%). Results indicated that the BIP showed significantly slower reflection pace and larger deviation, compared to the CAP. Irrespective of the pitch type, when the seam of the ball impacted the pitch, there was a significantly slower reflection pace and larger deviation. The reflection properties of the BIP resembled that of a “spinning pitch” which can be used as a form of representative practice for conditions similar to those that may be experienced in India. The impact of the seam on the pitch surface significantly altered the reflection of the ball and should be considered in future cricket research.

Impact of shoe and cleat type on youth baseball pitching biomechanics

ABSTRACT Shoulder and elbow injuries among baseball pitchers of various ages and abilities continue to rise despite exhaustive efforts analysing pitch type and count; however, it has yet been determined if footwear plays a role in altering pitching mechanics and subsequently injury susceptibility. Therefore, the purpose of the study was to investigate the effect footwear might have on youth baseball pitching mechanics. Data were collected on eleven youth baseball pitchers wearing two different shoes on two different surface inclinations. A repeated measures ANOVA was utilised to determine differences between upper and lower extremity joint kinematics and kinetics (p < 0.05). Results indicate wearing moulded cleats elicited significantly greater amounts of shoulder internal rotation torque, angle and velocity as well as elbow varus torque. Turf shoes caused an increased plantarflexion joint angle in the stride leg ankle and shoulder external rotation torque, angle and velocity. The findings of this study suggest that the footwear worn by a youth baseball pitcher does alter the shoulder and elbow dynamics in the dominant throwing arm as well as the amount of ankle plantarflexion in the stride leg.

FT-IR and GC–MS analyses of Dressel IA amphorae from the Grand Congloué 2 wreck

This research work is focused on the chemical characterization of the substance present in the internal surfaces of Roman amphorae that made them waterproof and on the identification of their content. The samples come from the wreck of the Grand Congloué 2 that was studied in the Bay of Marseille by Commander Cousteau in 1952. The twenty studied amphorae are of type Dressel 1A and were provided by Cosa in Etruria (Tuscany, Italy). The FT-IR analysis indicated different bands concerning organic matter, as the chemical link O–H from carboxylic acid, C–H of the methylene group and C–O of the methyl ester. The study carried out by GC–MS showed nineteen diterpenoids, such as dehydroabietic acid and retene, which are chemical markers of Pinaceae family. Methyl ester by-products were also characterized and they revealed a pitch pyrogenically prepared from resinous wood (Pinus sp.). Principal Component Analysis allowed to group all of the twenty studied amphorae in two lots indicating two types of pitch. Concerning the content of these amphorae, the results from pitch as well as shards allowed to detect the presence of tartaric and syringic acids which are the main markers of the red wine. The comparison study between pitch and shard samples of same amphorae indicates that pitch analyses has permitted to obtain a high qualitative and quantitative proportion of wine markers.

Effect of column inclination and oscillation on liquid spreading in a trickle bed

Gas–liquid–solid flow in a trickle bed installed on a floating production unit is affected by oscillations imparted by sea waves. The oscillations may affect the spreading of liquid, and in turn, the performance of a reactor. The present work investigates the effect of bed inclination and two types of oscillations (roll and roll+pitch) on the spreading of liquid in a cylindrical trickle bed with a single point liquid injection by using computational fluid dynamics. In the simulations, column tilt varied in a range of 0–15° and three oscillation frequencies (0.1, 0.2 and 0.5Hz) were considered. Initially, a three-phase Eulerian model was validated using the published experimental data for a stationary column. The effect of closure models such as capillary pressure model and Ergun drag model constants on predictions was analyzed for the selection of these closures. In a tilted column, liquid was pushed to flow in the direction of tilt. Increase in tilt angle from 0 to 15° resulted in increase in the flow segregation and ∼20% reduction in pressure drop. Oscillations (both roll and roll+pitch) resulted in more uniform liquid spreading and higher liquid holdup compared to a vertical column. With decrease in oscillation frequency, the index of uniformity in the radial liquid distribution further increased. The higher uniformity and liquid holdup caused by oscillations can be attributed to higher radial velocity of liquid due to the effect of gravity in the radial direction. Compared to the roll type oscillations, the roll+pitch type resulted in higher radial velocity and radial distribution of liquid.

Robert A. Millikan and the Oil Drop Experiment

In 2018, we celebrated the sesquicentennial birthday of Robert A. Millikan, a Nobel laureate in physics who worked among the greats such as Niels Bohr and Albert Einstein. His name, however, is perhaps not as widely known. He was born in 1868 in Morrison, IL, and moved with his family to the small town of Maquoketa, IA, at age nine. It was in this tiny Iowan town that Millikan spent his foundational years. He passed the time playing baseball and cooling off in the Maquoketa River. Millikan’s interest in experimentation showed early on. Local changes to the rules of baseball sparked controversy over a new type of pitch: the curve ball. Silas Millikan, Robert’s father, was a college-educated man and staunchly maintained that the curve ball was simply an optical illusion, but young Millikan knew better. With the help of brothers and cousins, Millikan set up a simple experiment to prove the point. Millikan and his family set up three poles in a line out in the yard and repeatedly pitched curveballs at one another. With careful observation, Silas could see the ball travel straight along the first two poles, then visibly curve and land on the opposite side of the third. This experiment was a small victory for Millikan, and only foreshadowed his later investment in scientific study.

Mean muscle activation comparison between fastballs and curveballs with respect to the upper and lower extremity

Baseball research on muscle activity (upper and lower extremity) during the throwing motion is important to understanding pitching mechanics for the future. Therefore, it is the purpose of this research study to compare the lower extremity muscle and upper extremity muscle activation patterns associated with the curveball pitch and the fastball pitch from the stretch position. Twelve skilled (NCAA collegiate level) pitchers volunteered to be in this study, with a mean age of 22.3 ± 4.53 years, mean height of 1.74 ± 0.13 m, and mean mass of 89.0 k ± 10.97 kg. The pitchers were fitted with six surface electromyography (EMG) bipolar electrodes on the stride leg biceps femoris, medial gastrocnemius, ipsilateral side lower trapezius, upper trapezius, triceps brachii and biceps brachii. Each pitcher underwent maximum voluntary isometric contraction (MVIC) testing and then performed the fastball & curveball pitching sequence. All EMG variables of interest were normalized using MVIC data and compared between pitching type. A repeated measures ANOVA was conducted for all muscle activity as well. If significance was found a pairwise analysis (Bonferroni) was performed between pitch type, using SPSS (p 0.05). Significant differences in the mean muscle activity for the fastball and curveball pitched from the stretch were observed. A higher level of muscle activity was found for the stretch fastball when compared to the stretch curveball. This study was able to provide a baseline measurement of muscle activity; however, kinematics and kinetics should be measured in future studies.

Different pitches for different stages of entrepreneurial development: the practice of pitching to business angels

ABSTRACT In this paper, we draw upon social practice theory as a lens through which to challenge commonly held assumptions about the practice of pitching. This study presents evidence suggesting that the commonly studied investment pitch, may in fact be part of a larger relational practice that plays out across time as entrepreneurs and their new businesses develop. We present findings from twenty-seven months of participant observation in an active angel investment organization located in the United States. Based on our observations, we discuss four types of pitch: developmental, pre-investment, investment, and update.

Manifestations of muscle fatigue in baseball pitchers: a systematic review.

BackgroundFatigue in baseball pitchers is a process linked to lowered physical and mental performance, injury, and changes in kinematics. Numerous studies have associated fatigue with overuse, high ball velocities, lack of rest time, poor mechanics, and degree of self-satisfaction. The aim of this study was to systematically review the literature to identify a theoretical framework for the relationship between outcomes and the manifestation of fatigue on baseball pitching. The synthesized data may identify areas requiring further research.MethodologyThis protocol was registered with PROSPERO (ID: CRD42018114194). SPORTDiscus, Medline, PubMed, Cochrane Database of Systematic Reviews, and Google Scholar were searched, using keywords such as fatigue in pitchers and changes in kinematics (e.g., pitching mechanics, valgus elbow torque), performance (e.g., pitch count, pitch type), and injury (e.g., pain, elbow, and shoulder soreness). Three reviewers independently screened the articles, selected relevant literature based on abstract eligibility, and assessed the methods described therein for final inclusion.ResultsA total of 31,860 articles were screened for eligibility and 25 articles were included for the review. The selected articles included epidemiological, longitudinal, experimental, conference papers, and crossover laboratory studies. Evidence extracted from the 25 studies demonstrates a relationship between fatigue in baseball pitching, and three overarching outcomes: changes in kinematics, a decrease in performance, and an increase in injury risk.ConclusionsFindings show that a co-dependence between changes in kinematics and a decrease in performance, which stems from central and peripheral fatigue, is a contributing factor of injury in baseball pitchers. A large percentage of baseball pitchers exhibit pain or soreness in either their elbow or shoulder, or both at some point in a season. Initially, kinematic changes occur that could maintain performance, but may increase joint and tissue loading. Performance decreased with elevated pitch counts and innings thrown, and pitching further into games or the season. Evidence was found to be consistent across all studies; however, more work is needed in the area of fatigue as an injury mechanism during pitching. With a proof of concept established, the prevention of negative outcomes associated with fatigue must be the focus of future research and performance should not be the only criteria.

The distribution and nature of responses to broadband sounds associated with pitch in the macaque auditory cortex

The organisation of pitch-perception mechanisms in the primate cortex is controversial, in that divergent results have been obtained, ranging from a single circumscribed ‘pitch centre’ to systems widely distributed across auditory cortex. Possible reasons for such discrepancies include different species, recording techniques, pitch stimuli, sampling of auditory fields, and the neural metrics recorded. In the present study, we sought to bridge some of these divisions by examining activity related to pitch in both neurons and neuronal ensembles within the auditory cortex of the rhesus macaque, a primate species with similar pitch perception and auditory cortical organisation to humans. We demonstrate similar responses, in primary and non-primary auditory cortex, to two different types of broadband pitch above the macaque lower limit in both neurons and local field potential (LFP) gamma oscillations. The majority of broadband pitch responses in neurons and LFP sites did not show equivalent tuning for sine tones.

Are Baseball Statistics an Appropriate Tool for Assessing Return to Play in Injured Players: An Analysis of Statistically Variability in Healthy Players Using a Machine Learning Approach

Objectives: Traditional pitching statistics (ERA, WHIP, etc) have been used as surrogates for pitcher performance without being validated. Even amongst healthy pitchers, the normal variability of these parameters has not yet been established. The purpose of this study was to determine the normal variability of basic and advanced pitching statistics in non-injured Major League Baseball (MLB) pitchers. It is our hope that this work will serve as the foundation for the identification and implementation of validated, pitcher dependent statistical measures that can be used to assess return to play performance following injury. Methods: Publicly available data from MLB Statcast and Pitch/Fx databases was used to analyze all non-injured MLB pitchers during 2015 and 2016 seasons who pitcher greater than 100 innings each season without injury. Traditional and advanced baseball pitching statistics were analyzed. The variability of each parameter was assessed by computing coefficient of variation (CV) between individual pitchers and across all pitchers. A CV below 10 is typically indicative of a relatively constant parameter, and parameters with a CV &gt; 10 are generally considered inconsistent and unreliable. Results: A total of 118 pitchers met all inclusion criteria. For each of these healthy pitchers, 38 basic/traditional parameters and 17 advanced parameters were analyzed. Of the traditional pitcher statistics, only 1 (3%) demonstrated a CV value &lt; 10 (average fastball velocity [FBv]; CV 1.5) (Figure 1). In advanced statistics, 9 of 17 (53%) variables demonstrated acceptable consistency as evidenced by a CV value &lt; 10 (Figure 2). Release position from plate (release_pos_y) along with velocity from the plate (vy0) where the two most constant advanced parameters. When separated by pitch type, these two parameters were the most constant (lowest CV) in every pitch type. Conclusion: The validity and variability of baseball statistics as surrogate markers for performance after injury/surgery have not yet been evaluated. It is critical that baseball statistics undergo proper vetting prior to being used to assess recovery. This study reveals average fastball velocity and release position from the plate to be the least variable basic and advanced baseball statistics in MLB pitchers. In total, only 10 of the 55 statistics analyzed demonstrated acceptable consistency and reliability. This study can be further used to determine the minimum time that each of these variables needs to be followed to ensure an appropriate sample size is obtained to detect significant differences in pre- and post- injury performance. [Figure: see text][Figure: see text]

Modifiable Mechanical Factors Associated with Increased Fastball Velocity

Objectives:The advent of motion and kinematic analysis of athletes during sport-specific activities has shed light on mechanical factors associated with improved athletic performance. This is especially true in baseball, where motion analysis has provided a nuanced understanding of the pitching motion. Previously, information from motion analysis has been used to identify risk factors for injury, such as to the medial elbow. However, there is less information regarding modifiable mechanical factors associated with increased performance that are safe and do not place the athlete at increased risk for injury. Identification of such variables would allow medical professionals to counsel pitchers on safe and effective ways to improve performance without risking injury. The goal of this study was to identify modifiable mechanical factors that were specific to pitchers throwing with above average fastball velocities.Methods:All participants were recruited from NCAA Division I and III collegiate baseball programs and all participants were currently pitching for their teams and had no history of injury in the preceding 6 months. Participants pitched from a 10-inch mound towards a target with a designated strike zone 60 feet 6 inches away. Each participant pitched the pitch types that they felt most comfortable pitching in a game setting, and pitches were thrown in random order to simulate a game setting. Motion data were collected at 250 Hz using a Vicon 512, 12-camera motion capture system (Vicon Motion Systems, Los Angeles, CA) using previously described methods. A single fastball pitch was randomly selected from each participant for analysis. The average ball velocity was used to place participants into either the ‘high velocity group’ (above average fastball velocity) or ‘low velocity group’ (below average ball velocity). A two-tailed unpaired t-test was performed to determine statistical significance of the variables measured during motion analysis to determine which mechanical differences between the two groups were associated with increased fastball velocity.Results:99 pitchers (avg. age 19.9 +/- 1.4) were enrolled in the study. The average velocity was 70.2 miles per hour (range 49.1 - 80.9). There were 57participants in the high velocity group and 42 participants in the low velocity group. Variables that were statistically different between the two study groups are listed in Table 1. A The high fastball velocity group showed decreased glenohumeral coronal angle at ball release (more ‘side arm’), increased anterior thoracic tilt at ball release, increased anterior pelvic tilt at ball release, increased pelvic obliquity at maximum glenohumeral external rotation (pelvis tilting up towards throwing arm), increased hip abduction at lead foot contact, and increased knee flexion at lead foot contact.Conclusion:The results indicated a number of modifiable variables that were significantly different between the two study groups. Using this information pitchers can look to modify their pitching motion to improve their performance as defined as increased fastball velocity. This information also provides a foundation for future work to determine which of these performance variables are also associated with increased medial elbow stresses that could lead to an increased risk of injury. Using this data could then allow coaches to optimize training regiments to focus on improving performance while minimizing risk of injury.Table 1:Variables associated with high velocity pitchers and low velocity pitchers with associated p-values. BR = ball release; MER = maximal glenohumeral external rotation; FC = foot contact.VariableHigh VelocityLow VelocityP ValuePitching Mechanics associated with increased VelocityGlenohumeral Coronal Angle at BR64.7°72.1°0.01A more ‘side arm’ position at BRThoracic Tilt at BR32.3°25.3°<0.0001Thorax leading towards home plate at BRPelvic Tilt at BR43.5°38.0°<0.0001Pelvis leading towards home plate at BRPelvic Obliquity at MER4.8°0.9°<0.0001Pelvis tilting up towards the throwing arm at late cocking phaseLead Hip Coronal Angle at FC37.0°33.8°0.03Increased lead hip abduction at FCLead Knee Sagittal Angle at FC43.6°40.3°0.03Increased lead knee flexion at FC

Acceptable timing error at ball-bat impact for different pitches and its implications for baseball skills

In baseball hitting, batters need high precision timing control to hit the ball with bat’s sweet spot. Knowing the acceptable range of timing error for hitting the ball in the aimed direction for various pitch types is helpful to understand whether the cause of the batter's mis-hit is a spatial or temporal error and highlight the motor skills required by the batter. The purpose of this study was to determine the acceptable timing error in different baseball pitches and the impact characteristics of mis-hits. Twenty-six high school baseball players hit a ball launched from a pitching machine with three types of pitches: fastballs, curveballs, and slowballs. We recorded the three-dimensional behavior of the ball, bat, and human body (pelvis) using an optical motion capture system. We then defined the optimal impact location based on timing accuracy, and determined the acceptable range of timing error by the interactive relationship between the horizontal orientation of the bat’s long axis at the time of ball impact and the horizontal direction of the batted ball. The ±30° width in the horizontal direction of the batted ball was set as the precondition for the tolerance of timing. The acceptable timing error was ±7.9 ms for fastballs, ±10.7 ms for curveballs, and ±10.7 ms for slowballs, and the optimal timing for outside pitches was approximately 10 ms later than that for inside pitches. The timing error was also explained 38.1% by variation in the impact location along the long axis of the bat (R2 = 0.381, P < 0.001) and was minimized at a position close to the bat’s sweet spot. These results suggest that the optimal impact location and acceptable range of timing error depend on the pitching course and speed and that timing accuracy is essential to achieve the spatial accuracy required to hit the ball at the bat’s sweet spot.

Differences in PlayerLoad and pitch type in collegiate baseball players

ABSTRACT PlayerLoad is derived from a tri-axial accelerometer device and is a measure of an athlete’s external training load. Tri-axial accelerometers (Optimeye S5, Catapult Sports, Melbourne, Australia) were worn by 25 collegiate pitchers during a pitching session. Pitches included fastballs, curve balls, sliders, and changeups. Peak and sum PlayerLoad were calculated for fastballs, curve balls, sliders, and changeups. Statistical analysis included paired t-tests (p < 0.01) and effect size indexes (ESI). Peak and sum PlayerLoad were higher for fastballs compared to changeups (N = 20; ESIpeak = 0.47, p= 0.001 and ESISum = 0.13, p = 0.001, respectively). Peak and sum PlayerLoad were not different comparing fastball to curveball (N = 12; ESIpeak = 0.24, p = 0.050 and ESISum<0.01, p = 0.106) and fastball to slider (N = 12; ESIpeak = 0.32, p = 0.088 and ESISum = 0.02, p = 0.221). Fastball velocity (37.1 ± 2.1 m/s) differed from the changeup (33.8 ± 1.9 m/s; p < 0.001), curveball (32.2 ± 1.2; p < 0.001), and slider (33.8 ± 1.3 m/s; p < 0.001). Pitching workload may differ based on pitch type. Pitch counts may not capture true player fatigue due to variability in stresses resulting from different pitch types.

Acute and Longitudinal Effects of Pitching on Passive Range of Motion in Division I Athletes

PURPOSE: To assess passive range of motion (ROM) measurements acutely over time and how this acute change alters over the course of a baseball season. METHODS: Seven healthy male NCAA Division I baseball pitchers were measured prior to the start of the season. Each pitcher was assessed for passive shoulder and elbow ROM, with measurements taken after each pitching bout during the season. Pitching bouts were allotted to early season, mid-season, or late season. In addition to ROM measurements, pitch volume, pitch type, and ball velocity were also collected for analysis. RESULTS: Following a pitching bout, passive shoulder external rotation decreased by 7% (p = 0.000) during the early season. However, passive shoulder internal rotation was significantly reduced during the early season (-37%; p = 0.001), mid-season (-30%; p = 0.000), and late season (-42%; p= 0.000). Further, total motion also decreased during the early season (-12%; p= 0.000), mid-season (-6%; p= 0.000), and late season (-9%; p= 0.000). In terms of pitch type, increasing the volume of fastballs thrown had a moderate correlation with loss of passive shoulder external rotation during the late season (r= -0.705). Increasing the volume of curveballs thrown had a moderate correlation with total motion lost during the late season (r= -0.665) as well as with passive elbow extension lost during mid-season (r= -0.760). CONCLUSIONS: Passive ROM is significantly impacted immediately after throwing. This decrease continues to be present throughout all parts of the baseball season. Moreover, a moderate correlation of fastballs and curveballs to losses in passive ROM indicates that attention to pitch type may be warranted, particularly during the middle and latter parts of the baseball season.

Effect of Bogie’s Quadrangular Height Difference on the Operation Safety of a Railway Passenger Coach

In order to study the influence of quadrangular height difference of the bogie on the operation safety of a 25T railway passenger coach, a multi-rigid-body dynamical model is built. In numerical simulations, the quadrangular height difference of a twisted type, a pitch type and a roll type are investigated, respectively. It shows that the quadrangular height difference has a negative effect on the operation safety, namely the derailment coefficient and the wheel unloading rate. It is found that the twist type affects most, followed by the roll type and the pitch type in turn. When the quadrangular height difference increases, the derailment coefficient and the wheel unloading rate increase. When the quadrangular height difference reaches up to 12 mm, the vehicle can be operated safely at 160 km/h on tangent track and at 90 km/h on a curved track with a radius of 500 m as well as passing through a twisted track at a quite low speed.

Professional and Amateur Pitchers' Perspective on the Ulnar Collateral Ligament Injury Risk.

Background:Medial ulnar collateral ligament (UCL) injury is increasingly prevalent in professional baseball pitchers, and significant research has been devoted to understanding the risk factors and prevention strategies associated with it. To date, no study has investigated what the players themselves believe causes and prevents the injury.Purpose:To evaluate the opinions of UCL injuries among pitchers, including professional athletes.Study Design:Cross-sectional study.Methods:A total of 214 baseball pitchers (45 high school/college, 169 Major League Baseball [MLB]/Minor League Baseball) completed a 52-item questionnaire designed to evaluate their opinions on the cause of UCL injuries, injury prevention, and Tommy John surgery. Overall, 51 of the 214 pitchers had previously experienced a UCL injury. The frequency of the selection of each answer option was measured. Additionally, chi-square tests were used to compare (1) responses between professional and nonprofessional pitchers and (2) responses between pitchers with and without a previous UCL injury.Results:Only 45% of pitchers thought that UCL injuries are avoidable in MLB. Additionally, 55% of pitchers with a UCL injury had a history of elbow injuries as an adolescent/child, compared with 18% in the uninjured group (P < .0001). Also, 72% of all surveyed pitchers agreed that fatigue over the course of a season increases the risk of UCL injuries, and the majority of pitchers agreed that inadequate rest from throwing both during the off-season (61%) and the season (59%) increases the risk of UCL injuries. Moreover, 59% of pitchers believed that a 6-man starting rotation would decrease the incidence of UCL injuries. Professional and nonprofessional pitchers significantly differed (P = .005) in the type of pitch most prone to causing UCL injuries.Conclusion:Pitchers with a previous childhood elbow injury had a significantly higher incidence of UCL injuries during their adult career, suggesting possible predisposition to UCL injury and warranting further research. Fatigue and inadequate rest were of greatest concern among all pitchers for an increased risk of UCL injuries. Understanding and acknowledging the opinions that players have regarding UCL injuries are important to improve UCL education, prevention, and treatment.