Batting performance of wood and metal baseball bats

INTRODUCTION/PURPOSE: Although metal baseball bats are widely believed to outperform wood bats, there are few scientific studies which support this. In a batting cage study, Greenwald et al. found that baseballs hit with a metal bat traveled faster than those hit with a wood bat, but the factors responsible for this difference in bat performance remain unidentified. The purpose of this study was to determine the effects of swing speed, impact location, and elastic properties of the bat on batted ball speeds. METHODS: The pitched ball, batted ball, and swings of two wood and five metal baseball bats by 19 different players were tracked in three dimensions at 500 Hz using a passive infrared motion analysis system. RESULTS: Increases in the batted ball speeds of metal bats over those of wood bats resulted from faster swing speeds and higher elastic performance with an apparent increase in the ball-bat coefficient of restitution. The contribution of these variables to batted ball speed differed with metal bat model. The "sweet spot" associated with maximum batted ball speeds was located approximately the same distance from the tip of wood bats as it was from metal bats. CONCLUSIONS: The variables that correlated with differences between metal and wood bat performance, and most notably differences in the percentage of faster batted balls, were identified using a novel kinematic analysis of the ball and bat. These variables and their correlation with bat performance should be applicable to other players and bats, although more skilled players and higher performing bats would likely result in even faster batted ball speeds.     

A numerical model for risk of ball-impact injury to baseball pitchers

INTRODUCTION: Metal baseball bats produce higher ball exit velocity (BEV) than wood bats, increasing the risk of impact injuries to infield players. In this paper, maximum BEV from a wood and a metal bat were determined using the finite element method. METHODS: Three-dimensional (3-D) bat kinematics at the instant of impact were determined from high-speed videography (N = 17 high-performance batters). A linear viscoelastic constitutive model was developed for stiffer and softer types of baseballs. The risk of impact injury was determined using available movement time data for adult pitchers; the data indicate that 0.400 s is required to evade a batted ball. RESULTS: The highest BEV (61.5 m.s(-1)) was obtained from the metal bat and the stiffer ball model, equating to 0.282 s of available movement time. For five impacts along the long axis of each bat, the "best case scenario" resulted from the wood bat and the softer ball (46.0 m.s(-1), 0.377 s). CONCLUSIONS: The performance difference between the bats was attributed to the preimpact linear velocity of the bat impact point and to differences in orientation on the horizontal plane. Reducing the swing moment of the baseball bat, and the shear and relaxation modulii of the baseball, increased the available movement time.     

Catastrophic injuries in high school and college baseball players

BACKGROUND: There are few epidemiologic studies of catastrophic baseball injuries. PURPOSE: To develop a profile of catastrophic injuries in baseball players and to describe relevant risk factors. STUDY DESIGN: Retrospective cohort study. METHODS: The authors reviewed 41 incidents of baseball injuries reported to the National Center for Catastrophic Sports Injury Research from 1982 until 2002. RESULTS: There were an estimated 1.95 direct catastrophic injuries per year, or 0.43 injuries per 100,000 participants. The most common mechanisms of injury were a collision of fielders (9) or of a base runner and a fielder (8), a pitcher hit by a batted ball (14), and an athlete hit by a thrown ball (4). Catastrophic injuries included 23 severe head injuries, 8 cervical injuries, 3 cases of commotio cordis, and 2 cases each of a collapsed trachea and facial fractures. Three athletes sustained a severe head injury and facial fractures. Ten of the 41 injuries were fatalities. CONCLUSIONS: Suggestions for reducing catastrophic injuries in baseball include teaching proper techniques to avoid fielding and baserunning collisions, protecting the pitcher via a combination of screens and/or helmets with faceguards, continued surveillance and modifications of the bat and ball, eliminating headfirst slides, and continued analysis of chest protectors and automatic external defibrillators for commotio cordis.     

A controlled study on batted ball speed and available pitcher reaction time in slowpitch softball

Objectives: To investigate safety risks in slowpitch softball by conducting laboratory and experimental studies on the performance of high tech softball bats with polyurethane softballs. To compare the results with the recommended safety standards.

Methods: ASTM standard compression testing of seven softball models was conducted. Using these seven softball models, bat/ball impact testing was performed using seven adult male softball players and six high tech softball bat models to determine mean batted ball speeds. Over 500 bat/ball impact measurements were recorded and analysed. Available pitcher reaction time was calculated from the mean batted ball speed measurements.

Results: According to the United States Specialty Sports Association and the Amateur Softball Association, the maximum initial batted ball speed should be 137.2 km/h, which corresponds to a minimum pitcher reaction time of 0.420 second. These experiments produced mean batted ball speeds of 134.0–159.7 km/h, which correspond to available pitcher reaction times of 0.409–0.361 second.

Conclusion: The use of high tech softball bats with polyurethane softballs can result in batted ball speeds that exceed the recommended safety limits, which correspond to decreased available pitcher reaction times.

     

The science of softball: implications for performance and injury prevention

Whilst the sport of softball has achieved worldwide popularity over the last 100 years, a consideration of the scientific principles underpinning softball is in its infancy. It is clear that the various motor skills associated with softball, such as pitching, batting and fielding, place considerable perceptual and physical demands upon players. Each of these skill categories are examined in more detail by reviewing the biomechanical principles associated with skilled performance. For pitching, a certain amount of information can be gleaned from baseball research; however, the underarm technique required by softball places the highest loads on the arm and shoulder during the accelerative, downward phase of the swing. Kinematic analyses of the bat swing suggest that elite batters have approximately 200 ms to decide whether to swing, and approximately the same duration to complete the swing (resulting in reported bat speeds of up to 40 m/sec). The research conducted on fielding has been limited to a consideration of throwing styles adopted in games. A variety of throwing techniques are adopted in the course of a typical game but elite players commonly adopt a sidearm technique when returning to base as quickly as possible. Data obtained from the National Athletic Training Association indicate a similar level of injury incidence in softball as in baseball. Approximately 17% of injuries are experienced by the pitcher and approximately 25% of all injuries are located in the forearm/wrist/hand joint segments. Sports science and sports medicine research have the potential to contribute significantly to performance enhancement and injury prevention in the future.     

Head injuries in children′s football—results from two prospective cohort studies in four European countries

Head injuries are considered harmful in children. We analyzed head and neck injuries in organized football in 7‐ to 12‐year‐old children. Data for this analysis were obtained from a prospective cohort study over two consecutive football seasons in two European countries, and a randomized intervention trial over one season in four European countries. Football exposure and injuries were documented through an online database. Detailed information regarding injury characteristics and medical follow‐up was retrieved from coaches, children and parents by phone. Thirty‐nine head injuries and one neck injury (5% of all 791 injuries) were documented during 9933 player‐seasons (total football exposure 688 045 hours). The incidence was 0.25 [95%CI 0.15, 0.35] head/neck injuries per 1000 match hours (N=23 match injuries) and 0.03 [95%CI 0.02, 0.03] per 1000 training hours. Eleven concussions (27.5%), nine head contusions (22.5%), eight lacerations or abrasions (20%), two nose fractures (2.5%), and two dental injuries (2.5%) occurred. The remaining eight injuries were nose bleeding or other minor injuries. Thirty injuries (75%) resulted from contact with another player, and ten injuries were due to collision with an object, falling or a hit by the ball. Whereas 70% of all head injuries (N=28) were due to frontal impacts, 73% of concussions (N=8) resulted from an impact to the occiput. The incidence and severity of head injuries in children′s football are low. Coaches and parents, however, should be sensitized regarding the potential of concussions, particularly after an impact to the occiput.     

Digital ischemia in baseball players

Eight baseball players developed digital ischemia as a result of repetitive ball impact. Symptoms and signs were coolness, numbness, cyanosis, paleness, and a positive reaction to the digital Allen's test. Seven of the eight players developed digital ischemia between the ages of 16 and 17. Angiograms of four patients with an occluded index digital artery are presented. Thermograms of four patients with a cool area of the left index finger are also presented. We investigated the incidence of digital ischemia by administration of a questionnaire. The respondents were 578 players belonging to clubs in junior high schools, high schools, and colleges. No digital ischemia was found in 207 junior high school baseball players. The incidence increased in high school (66 of 299) and college (29 of 72). The probability of developing digital ischemia corresponded to the accumulated playing time. Digital ischemia occurred characteristically in the left index finger.     

Effects of selected softball bat loading strategies on impact reaction impulse

Interior loading strategies to modify the location and size of the effective hitting area of aluminum softball bats were identified. The effects of these strategies on theoretically derived and empirically determined relevant mechanical parameters were compared. Loading strategies consisted of adding 315 g to the interior of three similar (790 g) aluminum softball bats: at the center of mass of the original bat (bat C); at the ends of the bat and distributed so that the center of mass was unchanged, (bat A); and at the ends of the bat and distributed so that the moment of inertia about the swing axis (I1) was the same as that of bat C (bat B). The following parameters were derived theoretically by considering the bat as a physical pendulum and empirically by observing the impact reaction impulse on the axis of suspension: moment of inertia about the suspension axis (I0); moment of inertia about the swing axis; distance from the suspension axis to the center of percussion; and the slope of the impact reaction impulse (P1) relative to the impact impulse (P) as a function of impact location. These values for each bat were compared. Both empirical and theoretically derived data indicated that: the center of percussion of bat B was farther away from the axis than bats A and C; the moment of inertia about the swing axis of bat A was much greater than that of bats B and C; and the slope of the impact reaction regression line as a function of impact location for bat B was significantly less than that of the other bats. Thus, the effective hitting area of bat B was moved toward the barrel end of the bat and enlarged without a substantial increase in the moment of inertia about the swing axis.     

Head and neck injuries in soccer. Impact of minor trauma.

Head injuries have been shown to account for between 4 and 22% of soccer injuries. Clinical and neuropsychological investigations of patients with minor head trauma have revealed organic brain damage. 69 active football (soccer) players and 37 former players of the Norwegian national team were included in a neurological and electroencephalographic (EEG) study to investigate the incidence of head injuries mainly caused by heading the ball. 3% of the active and 30% of the former players complained of permanent problems such as headache, dizziness, irritability, impaired memory and neck pain. 35% of the active and 32% of former players had from slightly abnormal to abnormal EEG compared with 13 and 11% of matched controls, respectively. There were fewer definitely abnormal EEG changes among typical 'headers' (10%) than among 'nonheaders' (27%). The former players were also subjected to cerebral computed tomography (CT), a neuropsychological examination and a radiological examination of the cervical spine. One-third of the players were found to have central cerebral atrophy and 81% to have from mild to severe (mostly mild to moderate) neuropsychological impairment. The radiological examination of the cervical spine revealed a significantly higher incidence and degree of degenerative changes than in a matched control group.     

Baseball and softball sliding injuries. Incidence, and the effect of technique in collegiate baseball and softball players

We prospectively observed seven softball and three baseball Division I collegiate teams to study the incidence of sliding injuries, the types of injuries resulting from the sliding technique, and the amount of time lost from participation. Slides were categorized as either feet- or head-first on the basis of the leading part of the body during the slide. Slides were further stratified depending on whether a diveback technique was performed. We recorded 37 injuries in 3889 slides in 637 games and 7596 athlete game exposures. The overall incidence of sliding injuries was 9.51 per 1000 slides and 4.87 per 1000 game exposures. Softball players had a significantly higher incidence of sliding injuries (12.13 per 1000 slides) than did baseball players (6.01 per 1000 slides). In baseball, the injury rate was higher for feet-first slides (7.31 per 1000 slides) than for headfirst slides (3.53 per 1000 slides) or divebacks (5.75 per 1000 divebacks). In softball, injury rates were higher for head-first slides (19.46 per 1000 slides) than for feet-first slides (10.04 per 1000 slides) or divebacks (7.49 per 1000 divebacks). The majority of injuries sustained were minor, with only four (11%) injuries causing the athlete to miss more than 7 days of participation.     

Effects of bat composition, grip firmness, and impact location on postimpact ball velocity

The purpose of this investigation was to examine the effects of bat composition (aluminum and wooden), impact location [center of percussion (COP), center of gravity (COG), and end of the bat (E)], and grip firmness [tight (T) and no tension (NT)] on postimpact ball velocity. With the bats placed alternately in NT and T conditions, baseballs were delivered at a speed of 27.1 m.s-1 from a pitching machine positioned 1.5 m from the bat. High-speed photography (400 fps) was performed using a Locam camera positioned 7.54 m from and perpendicular to the principal plane of ball movement. A three-way ANCOVA revealed significant (P less than 0.01) differences in postimpact ball velocity between the three impact locations, with the COP yielding the greatest values, followed by the COG and E. Moreover, there was a significant (P less than 0.01) grip vs bat interaction. A simple-effects procedure revealed the following results: 1) the T grip produced greater (P less than 0.01) velocities than the NT grip across the aluminum (Al) bat; 2) there was no difference (P greater than 0.01) between the T and NT grips across the wooden (W) bat; 3) the W bat produced greater (P less than 0.01) velocities than the Al bat across the NT grip; and 4) there was no difference (P greater than 0.01) between the Al and W bats across the T grip.(ABSTRACT TRUNCATED AT 250 WORDS)     

Heading and head injuries in soccer

In the world of sports, soccer is unique because of the purposeful use of the unprotected head for controlling and advancing the ball. This skill obviously places the player at risk of head injury and the game does carry some risk. Head injury can be a result of contact of the head with another head (or other body parts), ground, goal post, other unknown objects or even the ball. Such impacts can lead to contusions, fractures, eye injuries, concussions or even, in rare cases, death. Coaches, players, parents and physicians are rightly concerned about the risk of head injury in soccer. Current research shows that selected soccer players have some degree of cognitive dysfunction. It is important to determine the reasons behind such deficits. Purposeful heading has been blamed, but a closer look at the studies that focus on heading has revealed methodological concerns that question the validity of blaming purposeful heading of the ball. The player's history and age (did they play when the ball was leather and could absorb significant amounts of water), alcohol intake, drug intake, learning disabilities, concussion definition and control group use/composition are all factors that cloud the ability to blame purposeful heading. What does seem clear is that a player's history of concussive episodes is a more likely explanation for cognitive deficits. While it is likely that the subconcussive impact of purposeful heading is a doubtful factor in the noted deficits, it is unknown whether multiple subconcussive impacts might have some lingering effects. In addition, it is unknown whether the noted deficits have any affect on daily life. Proper instruction in the technique is critical because if the ball contacts an unprepared head (as in accidental head-ball contacts), the potential for serious injury is possible. To further our understanding of the relationship of heading, head injury and cognitive deficits, we need to: learn more about the actual impact of a ball on the head, verify the exposure to heading at all ages and competitive levels, determine stable estimates of concussive injury rates across the soccer spectrum, conduct prospective longitudinal studies on soccer players focusing on exposure, injury and cognition, and determine the minimum safe age to begin instruction on the skill of heading. Only then will we be able to speak with some authority on the issue of heading and head injuries in soccer.     

Injuries of the spine sustained during rugby

In 1984 JR Silver reported on 63 patients who had sustained serious injuries of their cervical spine as a result of games of rugby between the years 1952 and 1982. In this paper his results have been brought up to date. A further 19 players who were treated personally are reported, sustaining their injuries between 1983 and 1987. The mechanism of injury was still blows to the head or the head being driven into the ground. Seven injuries occurred in the scrums all were front row forwards. One was injured when the players charged, two players were inexperienced and the other cases all followed a collapse of the scrum after which the second rows continued to push. Five players were injured while tackling, six players were injured in a ruck and maul situation--in each case they were pushed to the ground while stooping to pick up the ball, other players piled on top of them (one player broke from the scrum and he endeavoured to retrieve a low ball and then fell striking his head). Further research was carried out by circularising all the spinal units in the United Kingdom to obtain the overall figures. It has been found that there has been a reduction in the number of injuries from ten in 1983 to five in 1986/7, presumably from a change in the laws. In order to determine whether a further change in the laws was necessary or whether the existing laws were adequate, research was carried out by video recording several games of rugby and analysing the games later in slow motion and determining how injuries occurred. Most of the injuries in these small number of games occurred in the ruck and maul situation. It was concluded that the majority of such injuries were not due to bad luck but were caused by irresponsible actions. The laws were still being broken and not being enforced. The existing laws were adequate since there has been a reduction in the number of injuries overall, particularly at first class and schoolboy levels, but were not enforced at junior levels-they were the main source of injury.     

Theoretical study of the effect of ball properties on impact force in soccer heading

PURPOSE: The objective of this study was to theoretically model, based on the Hertz contact theory, the impact force and contact time, as well as the linear and angular head accelerations during heading in children using two neck stiffness conditions (infinite and negligible stiffness). METHODS: The following mathematical model inputs were obtained: elastic modulus and mass of size three, four, and five balls at inflation pressures of 10, 12, and 14 psi, head modulus, head mass, head length, head and trunk moment of inertia, and the precontact ball velocity. The model outputs consisted of linear and angular head acceleration, impact force, contact time between the ball and head, and head impact criteria (HIC) all at the point of impact. Head mass and length were obtained as a percentage of body weight and height, respectively, based on age. RESULTS: With an increase in head mass, there is a decrease in the linear and angular head acceleration. With an increase in ball size, for the same head mass, there is an increase in the contact time between the head and the ball. Changing ball inflation pressure has little effect on the impact characteristics. Infinite neck stiffness decreased linear and angular head acceleration and HIC. CONCLUSION: Head mass and ball size have an effect on linear and angular head acceleration and contact time, respectively, whereas ball inflation pressure has a minimal effect on the impact characteristics. These results indicate that children should be restricted to using the appropriate ball for their age. Smaller head size within an age group is an underemphasized though important identifier of a player's injury risk.     

Unfälle bei großen Mannschaftsballsportarten

Soccer injuries result primarily from the competitive tackling character of this sports discipline. The predominant injuries are contusion trauma, followed by ankle sprains, knee distortions and heading injuries. Particularly serious injuries are caused by sliding tackles. Because of the smaller distances and space in indoor soccer, more goalkeepers are injured due to parrying than in outdoor soccer. Soccer disability cases are primarily injuries to the knee joint caused by various mechanisms, such as twisting of the knee with and without an external influence, falling injuries, unfortunate collisions and sliding tackles. In principle traumatic deaths may occur in any team ball game sport if there is unfortunate body contact between players. Fatal skull and brain trauma injuries in soccer can be differentiated into unfortunate heading actions, the head being directly hit by the ball and direct head-to-head contact with another player as well as collisions against goalposts and other pieces of equipment. Contusion accidents also dominate in handball. Here the so-called rapid counterattack may result in serious injuries due to the high forces involved. Handball disability cases mainly concern the knee joint and severe invalidity is primarily caused by external influences (i.e. the opponent). In volleyball and basketball ankle sprains are the dominating injury types (in volleyball often when stepping on an opponent’s foot), followed by playing the ball, where primarily the fingers are affected. In the USA eye injuries were frequently registered in basketball, due to finger or elbow contact with the opposing players. Severe injuries in rugby affect the head and neck in approximately one-third of the cases, in rare cases with spinal cord involvement. In American football serious injuries resulted especially from a direct attack on the opponent (tackling). After optimization of the football helmet design in the early 1970s, a clear reduction of skull and brain injuries was observed, but unfortunately a massive increase in neck injuries was also registered, because the helmeted head was now used as a weapon in tackling. After changes to the rules in 1978 these injury mechanisms have now declined again.     

Injuries in team sport tournaments during the 2004 Olympic Games

BACKGROUND: Several authors have analyzed the incidence of injuries in a given sport, but only a few have examined the exposure-related incidence of injuries in different types of sports using the same methodology. PURPOSE: Analysis of the incidence, circumstances, and characteristics of injuries in different team sports during the 2004 Olympic Games. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: During the 2004 Olympic Games, injuries in 14 team sport tournaments (men's and women's soccer, men's and women's handball, men's and women's basketball, men's and women's field hockey, baseball, softball, men's and women's water polo, and men's and women's volleyball) were analyzed. After each match, the physician of the participating teams or the official medical representative of the sport completed a standardized injury report form. The mean response rate was 93%. RESULTS: A total of 377 injuries were reported from 456 matches, an incidence of 0.8 injuries per match (95% confidence interval, 0.75-0.91) or 54 injuries per 1000 player matches (95% confidence interval, 49-60). Half of all injuries affected the lower extremity; 24% involved the head or neck. The most prevalent diagnoses were head contusion and ankle sprain. On average, 78% of injuries were caused by contact with another player. However, a significantly higher percentage of noncontact (57%) versus contact injuries (37%) was expected to prevent the player from participating in his or her sport. Significantly more injuries in male players (46%) versus female players (35%) were expected to result in absence from match or training. The incidence, diagnosis, and causes of injuries differed substantially between the team sports. CONCLUSION: The risk of injury in different team sports can be compared using standardized methodology. Even if the incidence and characteristics of injuries are not identical in all sports, prevention of injury and promotion of fair play are relevant topics for almost all team sports.     

Isolated complete ulnar collateral ligament tear of the elbow in a gymnast: does it need surgery?

Ulnar collateral ligament (UCL) tears can occur from trauma or chronic overuse, and the treatment depends on the type of sport the patient plays and the severity of symptoms. Overuse UCL injuries are most commonly due to micro-trauma in overhead athletes such as baseball players, softball players, and tennis players. Acute complete UCL tears in athletes due to trauma are less common but generally operative treatment is recommended. In gymnastics, elbow dislocations are more common than isolated UCL injuries, and there is sparse literature on the success of non-operative treatment of isolated UCL injuries in this group of athletes. In this case report, we report a high-level competitive gymnast with an UCL tear and a partial tear of the forearm flexor mass, which was confirmed by a thorough careful physical examination and magnetic resonance imaging. The patient was treated non-operatively and successfully returned to gymnastics without symptoms. This case supports the suggestion that UCL tears of the elbow can be treated successfully in some gymnasts without surgery, and that treatment should be individualized in this group of athletes.     

MR imaging of the shoulder in youth baseball players: Anatomy,pathophysiology, and treatment

With an increasing participation in youth sports and a growing popularity of overhead sports, shoulder pain and injuries are common in pediatric baseball players. In contrast to traumatic and collision injuries, which are more frequent with high-impact sports, many of the shoulder injuries are the result of repetitive overuse. Undiagnosed and untreated injury to the growth plates of skeletally immature athletes can lead to remodeling, which can negatively impact the biomechanics of the shoulder and produce long-term morbidity. Recently, there is an increasing emphasis on the association between skeletal maturation and injury patterns. The increasing use of magnetic resonance (MR) imaging has led to a better characterization of the traditionally radiographically-diagnosed growth plate injuries and awareness of other soft tissue and cartilaginous injuries that were previously thought to predominately occur in adult baseball players. The goal of this review is to: 1) highlight the normal anatomic changes that occur in the shoulder girdle during development and maturation; 2) discuss the biomechanical forces that are applied to the shoulder during a pitch; and 3) highlight the various injury patterns and adaptive remodeling that can occur in the shoulders of youth baseball athletes along with the current treatment options. These topics include growth plate injury, osteochondral injury, labral tear, capsular remodeling and rotator cuff tendinopathy.     

Head and neck injuries in college football: an eight-year analysis

The present study documented head and neck injuries in a study group of 342 college football players at a single institution for a period of 8 years. All freshmen players were screened for evidence of: (1) past history of head and neck injuries, and (2) abnormalities of the cervical spine on physical examination and x-ray film. By recording all head injuries and those neck injuries with time loss, incidence rates and patterns of injury incurred in college competition were determined. A total of 175 head and neck injuries were sustained by 100 players over the 8 year period. Those players with abnormal findings on screening examination were twice as likely to have a head or neck injury at some point in their college careers as those players with a normal screening examination. The greater the degree of abnormality on freshman screening examination, the more severe the neck injury in college was likely to be. Twenty-nine percent of all players in the study group sustained a head or neck injury during their college careers. The probability of a subsequent head or neck injury escalated sharply following a single incident. The overall incidence of injury was found to have been dramatically reduced over the 8 years. Influential factors such as legislative rule changes, medical status of recruits, and general coaching philosophies are discussed with regard to injury reduction and prevention of head and neck injuries in college football.