Objective: To construct interval throwing programs followed by a simulated game for collegiate softball players at all positions. The programs are intended to be used as functional progressions within a comprehensive rehabilitation program for an injured athlete or to augment off-season conditioning workouts.
Design and Setting: We collected data over a single season of National Collegiate Athletic Association softball at the University of Delaware and Goldey Beacom College. We observed 220 half-innings of play and 2785 pitches during data collection.
Subjects: The subjects were collegiate-level softball players at all positions of play.
Measurements: We recorded the number of pitches for pitchers. For catchers, we recorded the number of sprints to back up a play, time in the squat stance, throws back to the pitcher, and the perceived effort and distance of all other throws. We also collected the perceived effort and distance of all throws for infielders and outfielders.
Results: Pitchers threw an average of 89.61 pitches per game; catchers were in the squat stance 14.13 minutes per game; infielders threw the ball between 4.28 times per game and 6.30 times per game; and outfielders threw distances of up to 175 feet.
Conclusions: We devised the interval throwing programs from the data collected, field dimensions, the types of injuries found to occur in softball, and a general understanding of tissue healing. We designed programs that allow a safe and efficient progressive return to sport.
simulated game; college softball conditioning; rehabilitation for softball; softball injuries
Participation in high school sports has grown 16.1% over the last decade, but few studies have compared the overall injury risks in girls' softball and boys' baseball.
To examine the incidence of injury in high school softball and baseball players.
Greenville, South Carolina, high schools.
Patients or Other Participants:
Softball and baseball players (n = 247) from 11 high schools.
Main Outcome Measure(s):
Injury rates, locations, types; initial or subsequent injury; practice or game setting; positions played; seasonal trends.
The overall incidence injury rate was 4.5/1000 athlete-exposures (AEs), with more injuries overall in softball players (5.6/1000 AEs) than in baseball players (4.0/1000 AEs). Baseball players had a higher initial injury rate (75.9/1000 AEs) than softball players (66.4/1000 AEs): rate ratio (RR) = 0.88, 95% confidence interval (CI) = 0.4, 1.7. The initial injury rate was higher than the subsequent injury rate for the overall sample (P < .0001) and for softball (P < .0001) and baseball (P < .001) players. For both sports, the injury rate during games (4.6/1000 AEs) was similar to that during practices (4.1/1000 AEs), RR = 1.22, 95% CI = 0.7, 2.2. Softball players were more likely to be injured in a game than were baseball players (RR = 1.92, 95% CI = 0.8, 4.3). Most injuries (77%) were mild (3.5/1000 AEs). The upper extremity accounted for the highest proportion of injuries (63.3%). The incidence of injury for pitchers was 37.3% and for position players was 15.3%. The rate of injury was highest during the first month of the season (7.96/1000 AEs).
The incidence of injury was low for both softball and baseball. Most injuries were minor and affected the upper extremity. The injury rates were highest in the first month of the season, so prevention strategies should be focused on minimizing injuries and monitoring players early in the season.
injury rates; injury epidemiology; athletic injuries
Pain and injuries suffered by youth pitchers are ongoing concerns that have been addressed through the institution of rules and recommendations regarding pitch counts and rest periods. The aim of our study was to see if coaches of youth baseball pitchers in our region were aware of the recommended guidelines and if they followed them.
An Internet-based survey consisting of 18 items including demographic information and questions concerning the USA Baseball Medical and Safety Advisory Committee pitching guidelines was sent to coaches affiliated with a local youth league to assess their knowledge of and reported compliance with these recommendations.
Ninety-five of 228 coaches (41.4%) participated in the survey. On average, coaches answered 43% of questions regarding pitch count and rest periods correctly; 73% reported that they followed the recommendations, while only 53% felt that other coaches in the league abided by the recommendations. Thirty-five percent of coaches stated that their pitchers reported shoulder or elbow pain during the season, and 19% reported that one of their pitchers pitched a game with a sore or fatigued arm during the season. No coaches reported any pitching-related injuries among their players requiring surgery. Fewer than 10% of coaches reported that their players pitched in multiple leagues or participated in showcases, while 91% reported that pitchers attended camps or received specific instruction to improve their pitching form.
This study shows that this subset of youth baseball coaches is deficient with regard to knowledge of the USA Baseball Medical and Safety Advisory Committee pitching guidelines. This situation may put youth pitchers at increased risk for upper extremity pain and injuries.
pediatric; baseball; pitcher; injuries; pitch count
Representative data on typical pitch volume for collegiate pitchers functioning in their specific roles is sparse and is needed for training specificity.
To report pitch volumes in Division I collegiate pitchers. The authors hypothesize that pitcher role will result in different pitch volumes.
Pitchers from twelve Division I collegiate baseball teams pitch volume during the 2009 baseball season was retrospectively reviewed through each team's website. The number of pitches and innings pitched for each pitcher were recorded. Pitchers were categorized based on their role as “Starter-only” (n=15), “Reliever-only” (n=76), or “Combined Starter/Reliever” (n=94) and compared using ANOVA.
“Starter-only” pitchers threw the most pitches (97±10) and pitched the most innings (6.0±1.0) per appearance (p=<.001). “Combined Starter/Reliever” functioning as a starter threw significantly more pitches (68±19) and pitched more innings (4.0±1.3) per appearance compared to “Combined Starter/Reliever” functioning as a reliever and “Reliever-only” pitchers (p=<.001). The cumulative volume during a 13 week regular season revealed that “Starter-only” pitchers threw significantly more total pitches (1204±387) compared to “Combined Starter/Reliever” pitchers (613±182) who threw significantly more than “Reliever-only” pitchers (254±77) (P<.001).
Pitcher's specific roles and representative volumes should be used to design training and rehabilitation programs. Comparison of this data to reported adolescent pitch volumes reveal that adolescent pitch volume per appearance approaches collegiate levels.
Collegiate pitcher roles dictate their throwing volume. Starter-only pitchers (8%) throw the greatest cumulative number of pitches and should be trained differently than the majority of college pitchers (92%) who function primarily as a reliever or in combination starter/reliever roles that on average only requires approximately 40 pitches per appearance.
Overhead Throwing Athletes; Rehabilitation; Pitching
Addressing loss of shoulder range of motion and rotator cuff weakness in injury-prevention programs might be an effective strategy for preventing throwing arm injuries in baseball pitchers. However, the influence of these clinical measures on pitching biomechanics is unclear.
To evaluate the relationships among clinical measures of shoulder rotational motion and strength and 3-dimensional pitching biomechanics and to evaluate the presence of coupling between the shoulder and the elbow during pitching to provide insight into the influence of clinical shoulder characteristics on elbow biomechanics.
Patients or Other Participants:
A total of 27 uninjured male high school baseball pitchers (age = 16 ± 1.1 years, height = 183 ± 7 cm, mass = 83 ± 12 kg).
Main Outcome Measure(s):
Clinical measures included shoulder internal- and external-rotation range of motion and peak isometric internal- and external-rotator strength. Three-dimensional upper extremity biomechanics were assessed as participants threw from an indoor pitching mound to a target at regulation distance. Linear regressions were used to assess the influence of clinical measures on the peak shoulder internal and external rotation moments and the peak elbow-adduction moment.
We found a positive relationship between clinically measured internal-rotator strength and shoulder external-rotation moment (R2 = 0.181, P = .04) during pitching. We also noted an inverse relationship between clinically measured external-rotation motion and the elbow-adduction moment (R2 = 0.160, P = .04) and shoulder internal-rotation moment (R2 = 0.250, P = .008) during pitching. We found a positive relationship between peak shoulder internal-rotation moment and the peak elbow-adduction moment (R2 = 0.815, P < .001) during pitching.
This study provides insight into the effects of shoulder strength and motion on pitching biomechanics and how these clinical measures might contribute to throwing arm injuries in the baseball pitcher. A relationship also was identified between peak shoulder and elbow moments in the throwing arm during pitching, providing biomechanical support for addressing clinical shoulder characteristics as a potential strategy for preventing elbow injury.
upper extremity; overhead athletes; throwing athletes; rehabilitation
Although baseball is a relatively safe sport, numerous reports suggest a rapid rise in elbow injury rate among youth baseball pitchers.
PubMed was searched for epidemiologic, biomechanical, and clinical studies of elbow injuries in baseball (keywords: “youth OR adolescent” AND baseball AND pitching AND “ulnar collateral ligament OR elbow”; published January 2000 – April 2012). Studies with relevance to youth baseball pitchers were reviewed. Relevant references from these articles were also retrieved and reviewed. Original data, insight, and recommendations were added.
The majority of baseball elbow injuries are noncontact injuries to the dominant arm resulting from repetitive pitching. Five percent of youth pitchers suffer a serious elbow or shoulder injury (requiring surgery or retirement from baseball) within 10 years. The risk factor with the strongest correlation to injury is amount of pitching. Specifically, increased pitches per game, innings pitched per season, and months pitched per year are all associated with increased risk of elbow injury. Pitching while fatigued and pitching for concurrent teams are also associated with increased risk. Pitchers who also play catcher have an increased injury risk, perhaps due to the quantity of throws playing catcher adds to the athlete’s arm. Another risk factor is poor pitching biomechanics. Improper biomechanics may increase the torque and force produced about the elbow during each pitch. Although throwing breaking pitches at a young age has been suggested as a risk factor, existing clinical, epidemiologic, and biomechanical data do not support this claim.
Some elbow injuries to youth baseball pitchers can be prevented with safety rules, recommendations, education, and common sense. Scientific and medical organizations have published safety rules and recommendations, with emphasis on prevention of overuse and pitching while fatigued.
Strength-of-Recommendation Taxonomy (SORT):
pitcher; pitch count; ulnar collateral ligament; Tommy John surgery; curveball
Optimal baseball throwing mechanics require a significant contribution of thoracolumbar motion, particularly in the sagittal and transverse planes. This motion is key for proper transmission of forces from the lower to upper extremity, thereby minimizing a throwing athlete's risk of injury and maximizing athletic performance.
To define the active‐assisted thoracolumbar ROM of both baseball pitchers and position players and to compare these motions both within and between groups.
Fifty‐six asymptomatic, collegiate and minor league baseball pitchers and 42 position players volunteered to participate. Active‐assisted thoracolumbar flexion, extension, and bilateral rotation ROM, were measured in a standing position, using two bubble inclinometers. Two‐tailed t tests were used to determine differences in ROM between and within the pitchers and position players.
The pitchers had significantly more rotation to the non‐throwing arm side as compared to the position players (p = .007, effect size = .61). The pitchers also had more rotation to the non‐throwing arm side as compared to their throwing side (p = .006, effect size = .47). There were no other significant differences between the pitchers and the position players (p > .53). Furthermore, the position players did not have a side‐to‐side rotation difference (p = .99).
Pitchers have a greater amount of rotation ROM towards the non‐throwing arm side as compared to position players. Pitchers also have a greater amount of rotation ROM to the non‐throwing arm side as compared to their throwing side rotation. Because pitchers often present with posterior shoulder tightness and subsequent altered shoulder horizontal adduction and internal rotation ROM, the increase in non‐throwing side rotation ROM may occur in response to these adaptations. More specifically, this increase in non‐throwing side trunk rotation ROM may allow such athletes to bring the arm across the body during the follow‐through phase of the throwing motion despite posterior shoulder tightness. However, future research is necessary to investigate this relationship. Based on these results, clinicians should consider these thoracolumbar ROM adaptations in the prevention, evaluation, and treatment of baseball players.
Level of Evidence:
Flexibility; spine; throwing athlete; trunk
Baseball professionals believe that pitching from a mound can increase the stresses placed on the body.
There is no difference in kinematics or kinetics in pitching from a mound versus flat-ground conditions in adolescent baseball pitchers.
The fastball pitching motions of 15 adolescent baseball pitchers, including upper extremity kinematics and kinetics and lead- and trail-leg kinematics, were evaluated while pitching from the mound and flat ground. Student t tests were used to determine the differences between the 2 testing conditions.
Maximum external glenohumeral rotation was similar between the 2 conditions (134° ± 14° mound vs 133° ± 14° flat ground, P = 0.10). Ankle plantar flexion of the lead leg at ball release was greater in the flat-ground condition (−20° ± 10° mound vs −15° ± 12° flat ground, P = 0.01). A statistically significant increase in glenohumeral internal rotation moment (33.6 ± 12.1 Nm mound vs 31.7 ± 11.6 Nm flat ground, P = 0.01) and an increase in elbow varus moment (33.3 ± 12.3 Nm mound vs 31.4 ± 11.8 Nm flat ground, P = 0.02) was measured when pitching from the mound as compared with flat ground.
Pitching from the mound causes increased stress on the shoulder and elbow of adolescent pitchers as compared with that from flat ground.
The differences in kinematics as well as increased moments in the shoulder and elbow are helpful for pitchers and their coaches to know at the beginning of their season or as they return from injury or surgery. Pitchers in these situations should start their pitching progression on flat ground and progress to the mound.
baseball pitching; adolescent athletics; motion analysis
The ability to return to elite pitching, performance, and clinical outcomes of shoulder surgery in elite baseball pitchers are not definitively established.
To determine (1) the rate of return to sport (RTS) in elite pitchers following shoulder surgery, (2) postoperative clinical outcomes upon RTS, and (3) performance upon RTS and to compare RTS rates in different types of shoulder surgery.
Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and checklist, Medline, SciVerse Scopus, SportDiscus, and Cochrane Central Register of Controlled Trials were searched.
Levels I-IV evidence were eligible for inclusion if performance-based (eg, RTS) and/or clinical outcome–based reporting of outcomes were reported following surgical treatment of shoulder pathology in elite pitchers (major or minor league or collegiate).
Subject, shoulder, and pre- and postoperative performance-based variables of interest were extracted. All shoulder surgery types were potentially inclusive (eg, open, arthroscopic, rotator cuff, labrum, biceps, acromioclavicular joint, fracture). Study methodological quality was analyzed using the Modified Coleman Methodology Score (MCMS).
Six studies were analyzed (287 elite male pitchers [mean age, 27 years] who underwent shoulder surgery, with 99% on the dominant, throwing shoulder). MCMS was 38 (poor). Most pitchers were professional, with a mean career length of 6.58 years and postoperative clinical follow-up of 3.62 years. In 5 of 6 studies, multiple diagnoses were addressed concomitantly at surgery. Rate of RTS was 68% at mean 12 months following surgery. Twenty-two percent of Major League Baseball (MLB) pitchers never RTS in MLB. Overall performance did improve following surgery; however, this did not improve to pre-injury levels.
In this systematic review, the rate of return to elite baseball pitching following surgery was established. Performance tended to decrease prior to surgery and gradually improve postoperatively, though not reaching pre-injury levels of pitching.
Level of Evidence:
IV (systematic review of studies level I-IV evidence), therapeutic.
shoulder; surgery; arthroscopy; pitcher; Major League Baseball
Neuromuscular inhibition of the infraspinatus would be greater and external rotation muscle force would be lower after a simulated game compared with pregame values.
Materials and methods
The sample included 21 uninjured, asymptomatic high school–aged baseball pitchers. Maximum volitional shoulder external rotation strength was assessed before and after a simulated game with a clinical dynamometer. Voluntary activation of the infraspinatus was assessed during strength testing by a modified burst superimposition technique. Performance-related fatigue was assessed by monitoring pitch velocity, and global fatigue was assessed by subject self-report before and after the game. Statistical testing included paired and independent t tests, with α ≤ 05.
There was no difference between throwing and non-throwing shoulder external rotation strength (P = .12) or voluntary infraspinatus activation (P = .27) before the game. After the game, voluntary activation was significantly lower in the throwing limb compared with pregame activation levels (P = .01). Lower external rotation strength after the game approached statistical significance (P =.06). Pitch velocity was lower in the final inning compared with first-inning velocity (P = .01), and fatigue was significantly greater after the game (P = .01).
Voluntary infraspinatus muscle activation is a mechanism contributing to external rotation muscle weakness in the fatigued pitcher. Understanding mechanisms contributing to muscle weakness is necessary to develop effective injury prevention and rehabilitation programs. Treatment techniques that enhance neuromuscular activation may be a useful strategy for enhancing strength in this population.
Level of evidence
Basic Science Study, Kinesiology Study.
Baseball; rotator cuff; muscle; neuromuscular
Repetitive overhead throwing motion causes motion adaptations at the glenohumeral joint that cause injury, decrease performance, and affect throwing mechanics. It is essential to define the typical range of motion (ROM) exhibited at the glenohumeral joint in the overhead thrower.
We (1) assessed the glenohumeral joint passive range of motion (PROM) characteristics in professional baseball pitchers; and (2) applied these findings clinically in a treatment program to restore normal PROM and assist in injury prevention.
From 2005 to 2010, we evaluated 369 professional baseball pitchers to assess ROM parameters, including bilateral passive shoulder external rotation (ER) at 45° of abduction, external and internal rotation (IR) at 90° abduction while in the scapular plane, and supine horizontal adduction.
The mean ER was greater for the throwing and nonthrowing shoulders at 45° of abduction, 102° and 98°, respectively. The throwing shoulder ER at 90° of abduction was 132° compared with 127° on the nonthrowing shoulder. Also, the pitcher’s dominant IR PROM was 52° compared with 63° on the nondominant side. We found no statistically significant differences in total rotational motion between the sides.
Although we found side-to-side differences for rotational ROM and horizontal adduction, the total rotational ROM was similar.
The clinician can use these PROM values, assessment techniques, and treatment guidelines to accurately examine and develop a treatment program for the overhead-throwing athlete.
There is an assumption that baseball athletes who reside in warm-weather climates experience larger magnitude adaptations in throwing shoulder motion and strength compared with their peers who reside in cold-weather climates.
(1) The warm-weather climate (WWC) group would exhibit more pronounced shoulder motion and strength adaptations than the cold-weather climate (CWC) group, and (2) the WWC group would participate in pitching activities for a greater proportion of the year than the CWC group, with the time spent pitching predicting throwing shoulder motion and strength in both groups.
Cross-sectional study; Level of evidence, 3.
One hundred uninjured high school pitchers (50 each WWC, CWC) were recruited. Rotational shoulder motion and isometric strength were measured and participants reported the number of months per year they pitched. To identify differences between groups, t tests were performed; linear regression was used to determine the influence of pitching volume on shoulder motion and strength.
The WWC group pitched more months per year than athletes from the CWC group, with the number of months spent pitching negatively related to internal rotation motion and external rotation strength. The WWC group exhibited greater shoulder range of motion in all planes compared with the CWC group, as well as significantly lower external rotation strength and external/internal rotation strength ratios. There was no difference in internal rotation strength between groups, nor a difference in the magnitude of side-to-side differences for strength or motion measures.
Athletes who reside in cold- and warm-weather climates exhibit differences in throwing shoulder motion and strength, related in part to the number of months spent participating in pitching activities. The amount of time spent participating in pitching activities and the magnitude of range of motion and strength adaptations in athletes who reside in warm-weather climates may make these athletes more susceptible to throwing-related injuries.
glenohumeral joint; rotational motion; rotator cuff; throwing; youth athlete
An objective classification system for studying youth baseball players in the U.S.A. was published in 1996. Professional baseball is composed of greater than 25% international players a majority of whom come from five countries. Many youth baseball players are injured in early years play, both in the U.S.A. and internationally. There is no international classification system to study youth baseball pitching injuries, biomechanics, or maturation, but one is needed in order to compare and combine pitchers in multi‐center studies. Uniform domestic and international pre‐injury normative data is optimum. Ideally, data collection should be practical requiring inexpensive equipment and limited time demands.
The mathematical model, developed in 1996 on 853 boys and validated on 114 boys in the Mid‐Atlantic Region, U.S.A., is internationally applicable, allowing easy classification of youth baseball pitchers and levels throughout the world.
Seven‐hundred‐twenty‐one international pitchers, ages 8‐14, threw five full‐speed pitches recorded with a calibrated radar gun and four maximum distance throws on a marked field. Demographics included age, height, weight, and years pitched. Collection sites included foreign national baseball clubs (Dominican Republic, Venezuela, Puerto Rico, Japan and the Philippines), the Mexican national youth tournament, and a multinational tournament (Brazil, Peru and Colombia). The mathematical model developed in 1996 was used to generate predicted distances for this sample for comparison with actual distances. In addition to the overall analysis, adequate sample sizes were available for comparing predicted and actual distances by country for four of the countries.
The correlation between predicted distance using the mathematical model and actual distance was 0.90. The mean of the international players was 1‐2 standard deviations above the USA mean for speed and one standard deviation above the mean for distance. There was no systematic over or under prediction indicating that both relative and absolute fit for the model was excellent.
The mathematical model developed in 1996 on U.S.A. baseball players is robustly generalizable to international youth baseball pitchers.
Pre‐injury distance/speed data allows for classification of youth baseball player of multiple levels between the ages of 8‐14. International and regional comparisons are now possible for multi‐center studies in order to better define risk factors, compare studies, and combine data based upon pre‐injury maximum long toss data. Data collection requires only a field, a few balls, and a tape measure.
Throwing is a vigorous activity that generates large internal loads. There is limited evidence of the effect of these loads on bone adaptation. The aim of this study was to investigate the: 1) magnitude of bone adaptation within the midshaft humerus of female fast-pitch softball players and 2) influence of throwing mechanics (windmill vs. overhand throwing) on the magnitude of adaptation.
Midshaft humeral bone mass, structure and estimated strength were assessed via peripheral quantitative computed tomography in fast-pitch softball players (throwers; n=15) and matched controls (controls; n=15). The effect of throwing was examined by comparing dominant-to-nondominant differences in throwers to controls, while the influence of mechanics was determined by comparing dominant-to-nondominant differences in throwers who primarily play as pitcher (windmill thrower), catcher (overhand thrower) or fielder (overhand thrower).
Throwers had greater dominant-to-nondominant difference in midshaft humeral bone mass, structure and estimated strength relative to controls (all P<0.05). The largest effect was for estimated torsional strength with throwers having a mean dominant-to-nondominant difference of 22.5% (range, 6.7% to 43.9%) compared to 4.4% (range, -8.3% to 17.5%) in controls (P<0.001). Throwing mechanics appeared to influence the magnitude of skeletal adaptation, with overhand throwers having more than double dominant-to-nondominant difference in midshaft humeral bone mass, structure and estimated strength than windmill throwers (all P<0.05).
Throwing induces substantial skeletal adaptation at the midshaft humerus of the dominant upper extremity. Throwing mechanics appears to the influence the magnitude of adaptation as catchers and fielders (overhand throwers) had twice as much adaptation as pitchers (windmill throwers). The latter finding may have implications for skeletal injury risk at the midshaft humerus in throwing athletes.
BIOMECHANICS; BONE; EXERCISE; GROWTH AND DEVELOPMENT; MECHANICAL LOADING; OSTEOPOROSIS
Little is known about pitching performance or lack of it among Major League Baseball (MLB) pitchers who undergo operative treatment of rotator cuff tears.
To assess pitching performance outcomes in MLB players who needed operative treatment of rotator cuff tears and to compare performance in these athletes with that in a control group of MLB players.
Publicly available player profiles, press releases, and team injury reports.
Patients or Other Participants:
Thirty-three MLB pitchers with documented surgery to treat rotator cuff tears and 117 control pitchers who did not have documented rotator cuff tears were identified.
Main Outcome Measure(s):
Major League Baseball pitching attrition and performance variables.
Players who underwent rotator cuff surgery were no more likely not to play than control players. Performance variables of players who underwent surgery improved after surgery but never returned to baseline preoperative status. Players who needed rotator cuff surgery typically were more experienced and had better earned run averages than control players.
Pitchers who had symptomatic rotator cuff tears that necessitated operative treatment tended to decline gradually in performance leading up to their operations and to improve gradually over the next 3 seasons. In contrast to what we expected, they did not have a greater attrition rate than their control counterparts; however, their performances did not return to preoperative levels over the course of the study.
pitching; clinical outcome; shoulder
The magnitude of motion that is normal for the throwing shoulder in uninjured baseball pitchers has not been established. Chronologic factors contributing to adaptations in motion present in the thrower's shoulder also have not been established.
To develop a normative profile of glenohumeral rotation motion in uninjured high school baseball pitchers and to evaluate the effect of chronologic characteristics on the development of adaptations in shoulder rotation motion.
Baseball playing field.
Patients or Other Participants:
A total of 210 uninjured male high school baseball pitchers (age = 16±1.1 years, height = 1.8 + 0.1 m, mass = 77.5±11.2 kg, pitching experience = 6±2.3 years).
Using standard goniometric techniques, we measured passive rotational glenohumeral range of motion bilaterally with participants in the supine position.
Main Outcome Measure(s):
Paired t tests were performed to identify differences in motion between limbs for the group. Analysis of variance and post hoc Tukey tests were conducted to identify differences in motion by age. Linear regressions were performed to determine the influence of chronologic factors on limb motion.
Rotation motion characteristics for the population were established. We found no difference between sides for external rotation (ER) at 0° of abduction (t209 = 0.658, P = .51), but we found side-to-side differences in ER (t209 = −13.012, P<.001) and internal rotation (t209 = 15.304, P<.001) at 90° of abduction. Age at the time of testing was a significant negative predictor of ER motion for the dominant shoulder (R2 = 0.019, P = .049) because less ER motion occurred at the dominant shoulder with advancing age. We found no differences in rotation motion in the dominant shoulder across ages (F4,205 range, 0.451–1.730, P>.05).
This range-of-motion profile might be used to assist with the interpretation of normal and atypical shoulder rotation motion in this population. Chronologic characteristics of athletes had no influence on range-of-motion adaptations in the thrower's shoulder.
shoulder; throwing; range of motion
The purpose of this study was to clarify differences in the kinematic and kinetic profiles of the trunk and lower extremities during baseball pitching in collegiate baseball pitchers, in relation to differences in the pitched ball velocity. The subjects were 30 collegiate baseball pitchers aged 18 to 22 yrs, who were assigned to high- (HG, 37.4 ± 0.8 m·s-1) and low-pitched-ball-velocity groups (LG, 33.3 ± 0.8 m·s-1). Three-dimensional motion analysis with a comprehensive lower-extremity model was used to evaluate kinematic and kinetic parameters during baseball pitching. The ground-reaction forces (GRF) of the pivot and stride legs during pitching were determined using two multicomponent force plates. The joint torques of hip, knee, and ankle were calculated using inverse-dynamics computation of a musculoskeletal human model. To eliminate any effect of variation in body size, kinetic and GRF data were normalized by dividing them by body mass. The maxima and minima of GRF (Fy, Fz, and resultant forces) on the pivot and stride leg were significantly greater in the HG than in the LG (p < 0.05). Furthermore, Fy, Fz, and resultant forces on the stride leg at maximum shoulder external rotation and ball release were significantly greater in the HG than in the LG (p < 0.05). The hip abduction, hip internal rotation and knee extension torques of the pivot leg and the hip adduction torque of the stride leg when it contacted the ground were significantly greater in the HG than in the LG (p < 0.05). These results indicate that, compared with low-ball-velocity pitchers, high-ball-velocity pitchers can generate greater momentum of the lower limbs during baseball pitching.
Key pointsHigh-ball-velocity pitchers are characterized by greater momentum of the lower limbs during pitching motion.For high-pitched-ball velocity, stabilizing lower limbs during pitching plays an important role in order to increase the rotation and forward motion of the trunk.Computation of the lower-extremity kinetics and measurement of lower-extremity strength may help clarify the role of muscle strength in determining knee and hip function in baseball pitching.
Throwing movement; pitching ball velocity; ground-reaction force; lower limbs; pivot and stride legs
The aim of this descriptive epidemiology study was to evaluate the injury incidence, pattern and type as a function of position in one professional baseball organization for one complete season. The study was carried out in a major academic center. Participants were all major/minor league baseball players playing for one professional organization. The disabled/injury list of one single professional baseball organization (major and minor league players) was reviewed for all of the injuries and the number of total days missed secondary to each injury. All injuries were categorized into major anatomic zones that included: shoulder, elbow, wrist/hand, back, abdomen/groin, hip, knee, and ankle/foot. The data was further stratified based on the injury type and the number of days missed due to that particular injury and a statistical analysis was performed. In pitchers, elbow injuries (n=12) resulted in 466 days missed. In catchers, wrist injuries (n=4) resulted in 89 days missed. In position players, abdominal/groin injuries (n=16) resulted in 318 days missed and shoulder injuries (n=9) resulted in 527 days missed. Overall, 134 players were injured and a total of 3209 days were missed. Pitchers had 27 times and 34 times the rate of days missed due to elbow injuries compared to position players and all players, respectively. Abdominal and groin injuries caused the pitchers to have 5.6 times and 6.4 times the rate of days missed than the position and all players, respectively. Both elbow and abdominal/groin injuries are the most disabling injury pattern seen in pitchers. Among the position players, shoulder injuries resulted in the most days missed and knee injuries resulted in the highest rate of days missed in both pitchers and catchers.
MLB baseball; epidemiology; upper body injuries; lower body injuries; abdominal/ groin injuries.
A database describing the range of normal rotator cuff strength values in uninjured high school pitchers has not been established. Chronologic factors that contribute to adaptations in strength also have not been established.
To establish a normative profile of rotator cuff strength in uninjured high school baseball pitchers and to determine whether bilateral differences in rotator cuff strength are normal findings in this age group.
Baseball playing field.
Patients or Other Participants:
A total of 165 uninjured male high school baseball pitchers (age = 16 ± 1 years, height = 1.8 ± 0.1 m, mass = 76.8 ± 10.1 kg, pitching experience = 7 ± 2 years).
Main Outcome Measure(s):
Isometric rotator cuff strength was measured bilaterally with a handheld dynamometer. We calculated side-to-side differences in strength (external rotation [ER], internal rotation [IR], and the ratio of ER:IR at 90° of abduction), differences in strength by age, and the influence of chronologic factors (participant age, years of pitching experience) on limb strength.
Side-to-side differences in strength were found for ER, IR, and ER:IR ratio at 90° of abduction. Age at the time of testing was a significant but weak predictor of both ER strength (R2 = 0.032, P = .02) and the ER:IR ratio (R2 = 0.051, P = .004) at 90° of abduction.
We established a normative profile of rotator cuff strength for the uninjured high school baseball pitcher that might be used to assist clinicians and researchers in the interpretation of muscle strength performance in this population. These data further suggested that dominant-limb adaptations in rotator cuff strength are a normal finding in this age group and did not demonstrate that these adaptations were a consequence of the age at the time of testing or the number of years of pitching experience.
shoulder; muscle physiology; throwing
It is important to understand the loading conditions when considering the pathology of shoulder disorders in overhead athletes. However, because throwing is a complicated motion and methods to directly determine stress distribution are complex, direct measurement of the stress distribution across the glenohumeral joint has not been attempted. Subchondral bone density reportedly reflects the cumulative stress acting on a joint surface under actual loading conditions.
To assess alterations in stress distribution across the glenoid cavity caused by pitching, we investigated the distribution of subchondral bone density in nonathletic volunteers and asymptomatic baseball players, including fielders and pitchers.
We collected CT imaging data from the dominant-side shoulder of 10 nonathletic volunteers (controls), 10 fielders, and 10 pitchers in a competitive college baseball league (all men aged 19–24 years, mean 20.7 years). We measured the distribution of subchondral bone density of the glenoid cavity using CT osteoabsorptiometry. The obtained stress distribution map was divided into four segments: anterosuperior, anteroinferior, posteroinferior, and posterosuperior regions. We quantitatively analyzed the location and percentages of high-density regions on the articular surface.
The percentages of high-density regions, including the anteroinferior and posterior segments, were greater in pitchers and fielders than in controls. The percentages of high-density regions did not differ between pitchers and fielders.
The bicentric density patterns indicated that the cumulative force of pitching activity affected the long-term stress distribution across the glenoid cavity.
Our data should be useful for analyzing pitching activity and clarifying the pathology of shoulder disorders associated with throwing.
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.
Baseball pitching kinematics, kinetics, ball velocity, and injuries at the shoulder and elbow are related.
PubMed and Sport Discus were searched for original studies published between 1994 and 2008. Relevant references in these studies were retrieved. Inferential studies that tested relationships between kinematics and kinetics were included, as were studies that tested relationships between kinematics and ball velocity. Descriptive studies that simply quantified kinematics and/or kinetics were excluded.
Several kinematic parameters at the instant of foot contact were associated with increased upper extremity kinetics: front foot position, front foot orientation, shoulder abduction, and shoulder horizontal adduction. The timing of shoulder external rotation, pelvis rotation, and upper trunk rotation was associated with increased kinetics and decreased ball velocity. Low braking force of the lead leg and a short stride were associated with decreased ball velocity. Decreased maximum shoulder external rotation, shoulder abduction, knee extension, and trunk tilt were also associated with decreased ball velocity. As pitchers develop, kinematic values remain similar, their variability reduces, and kinetic values gradually increase. Slight kinematic variations were seen among pitch types, although the kinetics of fastballs and curveballs were relatively the same; changeup kinetics were the lowest. As pitchers fatigued, kinetic values remained constant, but increases in arm pain were reported.
Several kinematic parameters were related to joint kinetics and ball velocity. To enhance performance and reduce injury risk, pitchers need to learn proper fastball mechanics at an early age. A changeup is recommended as a safe secondary pitch to complement the fastball; the curveball can be added after fastball and changeup mechanics are mastered. Avoiding overuse and pitching while fatigued is necessary to minimize the risk of arm injury.
shoulder; elbow; ball velocity; kinetics; mechanics
To review the literature of the biomechanics of the windmill fast-pitch and its implications for injury. This information may be utilized in treating youth windmill pitchers.
A MEDLINE search was conducted to retrieve articles regarding the windmill pitch. Key terms were then taken from the pilot search and used to conduct a systematic search and review of the literature.
Articles containing information on the windmill pitch and injuries associated with the motion were reviewed. Additional information pertaining to the overhand baseball pitch and overuse injuries in youth were analyzed and synthesized into the body of information.
A complex sequence of actions is required to successfully perform the windmill pitch. Overuse injuries are common in windmill pitchers. A well-designed conditioning schedule and the regulation of the frequency and volume of pitching in youth fast-pitch may assist with managing injury associated with this activity. Further investigation of specific treatment methods is needed.
Biomechanics; Underhand Pitching; Softball; Chiropractic; Shoulder; Elbow
Tissue adaptations in response to pitching are an expected finding
during magnetic resonance imaging (MRI) evaluation of the throwing elbow of
adult pitchers. These changes are considered normal in the absence of
symptom complaints. It is unclear when during the playing career these
tissue adaptations are initiated.
Abnormalities in the appearance of the throwing elbow compared with
the nonthrowing elbow would be visible during MRI assessment of this
asymptomatic population of high school–aged throwers.
Cross-sectional study; Level of evidence, 3.
Twenty-three uninjured, asymptomatic male high school–aged
baseball pitchers (mean age, 16 years) with no history of elbow injury were
recruited for the study. Participants had a minimum of 3 years’
experience with pitching as their primary position (mean experience, 6
years). Bilateral elbow MRI examinations were performed using a standardized
protocol including fast spin-echo proton-density (axial and coronal),
T1-weighted (sagittal), and T2-weighted fat-saturated (axial, sagittal, and
coronal) sequences. Osteoarticular, ligamentous, musculotendinous, and
neural structures were evaluated and compared bilaterally. The images were
reviewed by a musculoskeletal radiologist who was blinded to all the
gathered data on these athletes, including limb dominance.
Three participants (13%) had no abnormalities. Fifteen
individuals (65%) had asymmetrical anterior band ulnar collateral
ligament thickening, including 4 individuals who also had mild sublime
tubercle/anteromedial facet edema. Fourteen participants (61%) had
posteromedial subchondral sclerosis of the ulnotrochlear articulation,
including 8 (35%) with a posteromedial ulnotrochlear osteophyte, and
4 (17%) with mild posteromedial ulnotrochlear chondromalacia. Ten
individuals (43%) had multiple abnormal findings in the throwing
Thickening of the anterior band of the ulnar collateral ligament and
posteromedial subchondral sclerosis of the trochlea are common findings in
the high school–aged pitcher and may be considered normal clinical
findings in the absence of symptom complaints. Other changes in tissue
appearance of the throwing elbow are uncommon in this age group and should
be regarded with a higher level of caution when evaluating for the presence
of injury. An understanding of the MRI appearance of the uninjured youth
pitcher is necessary for clinicians to distinguish between normal
adaptations and the presence of injury.
overhead athlete; MRI; ulnar collateral ligament
Adolescents ranging in age from 11–15 (early‐mid adolescence) comprise the largest percentage of baseball and softball athletes in the United States. Shoulder and elbow injuries are commonly experienced by these athletes with baseball pitchers and softball position players most likely to be injured.
Physeal injury often termed “Little League” shoulder or elbow is common and should be differentiated from soft tissue injuries such as biceps, rotator cuff, or UCL injuries. Regardless of diagnosis, rehabilitation of these athletes’ shoulder and elbow injuries provide a unique challenge given their rapidly changing physical status.
Common impairments include alterations in shoulder range of motion, decreased muscle performance, and poor neuromuscular control of the scapula, core, and lower extremity. A criterion based, progressive rehabilitation program is presented. Discharge from formal rehabilitation should occur only when the athlete has demonstrated a resolution of symptoms, acceptable ROM, muscle performance, and neuromuscular control while progressing through a symptom free return to sport.
Prevention of Reinjury:
Reintegration into the desired level of sport participation should be guided by the sports medicine professional with a focus on long‐term durability in sport performance as well as injury prevention. A prevention program which includes parent, coach, and athlete education, regular screening to identify those athletes at the highest risk, and monitoring athletes for the development of risk factors or warning signs of injury over the course of participation is indicated.
Level of Evidence:
Adolescent; throwing injuries; youth