High School Baseball Pitchers Research Articles

고교야구 투수의 투구 속도 차이에 따라 신체조성, 각 관절별 등속성근력 비교

고교야구 투수의 투구 속도 차이에 따라 신체조성, 각 관절별 등속성근력 비교

Relationship Between Glenohumeral Internal Rotation Deficit and Medial Elbow Torque in High School Baseball Pitchers

Background: Alterations in throwing mechanics have been identified as a risk factor for overuse injuries in baseball players. Glenohumeral internal rotation deficit (GIRD) has been found to adversely affect throwing mechanics, but the effect of GIRD on medial elbow torque is unclear. Purpose: To investigate the relationship between GIRD and medial elbow torque in high school–aged baseball pitchers. Study Design: Descriptive laboratory study. Methods: High school baseball pitchers (14-18 years old) were recruited for participation in this study. Players’ height, weight, body mass index, and arm measurements were recorded as well as shoulder and elbow range of motion measurements. GIRD was calculated from the difference between dominant and nondominant shoulder internal rotation. Participants then pitched 5 fastballs at maximum effort while wearing a wireless sensor that recorded elbow torque, arm slot, arm speed, shoulder rotation, and ball velocity. Principal component analysis was performed to determine which variables were associated with elbow torque or ball velocity. Results: Twenty-three high school pitchers participated in this study; 35% (n = 8) of participants exhibited GIRD of at least 20°. The mean GIRD was 15.3°± 11.2° and was not a predictor of medial elbow torque (P = .205) or ball velocity (P = .333). Ball velocity, age, and height were predictors of medial elbow torque (P = .012, P = .003, and P = .024, respectively). Conclusion: In high school baseball pitchers, GIRD was not associated with medial elbow torque during the pitching motion. Instead, ball velocity, player age, and player height carried greater significance. Clinical Relevance: This study suggests that high school pitchers with GIRD do not have an inherently greater risk for increased medial elbow torque during the throwing motion. It is recommended that pitchers instead assess their ball velocity to evaluate for relative differences in medial elbow torque.

Does Perceived Effort Match Actual Measured Effort During Baseball Long Toss Programs?

Objectives: Progressive throwing programs are a mainstay of rehabilitating the throwing athlete after injury or surgery. Athletes are commonly asked to throw at reduced levels of effort (i.e. “50% effort”, ”75%,” etc) to minimize stress to healing tissues. However, it is unknown whether players’ perceived exertion matches actual exertion. The purpose of this study was to determine whether decreased effort correlates with decreased throwing metrics, whether metrics decrease to a predictable degree, and to quantify variability of these metrics within a given athlete when attempting to throw at sub-maximal effort. Methods: Sixty healthy, high school and collegiate baseball pitchers participated in a structured throwing program. After warming up, each pitcher was asked to throw five, max effort long toss throws at a distance of 120 feet. Afterwards, they were asked to give 5 throws at both 75% effort and 50% effort from the same distance. A motusBASEBALL sleeve (Motus Global, Inc.; Massapequa, NY) was worn by all players, which measured arm slot, velocity, shoulder rotation, and elbow varus torque (Nm). Ball velocity was measured in miles per hour (MPH) using a radar gun. The observed changes in throwing metrics were compared to one another across each of the throwing scenarios using a general estimating equation to control for multiple comparisons. They were also compared to the expected change to see if a decrease from 100% effort to 75%, and then to 50% resulted in proportional decreases in elbow torque and ball velocity. Intra-thrower variability was determined for each throwing metric at each degree of effort, and these results are reported using intra-class correlation coefficients (ICC) where an ICC > 0.75 was considered to represent excellent agreement. Results: Mean elbow torque decreased as players decreased their perceived effort from 100% (72.7 Nm) to 75% (67.3 Nm) to 50% (62.s Nm) (p<0.001). Mean ball velocity also decreased as they progressed from 100% effort (77.8 MPH) to 75% effort (66.5) to 50% effort (60.3 MPH) throws (p<0.001). However, these observed decreases in torque and velocity were much smaller in magnitude than the decreases in perceived effort. During the 75% effort throws, torque and velocity were not reduced to 75% of max. Instead, elbow torque was only reduced to 93.3% of max, and velocity dropped to 86.1% of max. Similarly, for the 50% effort throws, torque remained 86.5% of max effort torque, while velocity remained 78.1% of max. Accordingly, for every 25% decrease in perceived effort, torque only decreased 7%, and velocity only decreased 11%. These observed differences were all significantly different than the expected differences (p<0.001 for all). Intra-thrower reliability was considered excellent for all metrics within each throwing scenario: max effort, 75% effort, and 50% effort (ICC>0.75 for all). Conclusion: Measured effort was significantly greater than perceived effort during this standardized throwing program for all metrics tested. This is especially true for ball velocity and varus elbow torque. Ultimately, when players throw at what they perceive to be “reduced effort,” their actual throwing metrics do not decrease at the same rate as their perceived exertion. This has significant implications for throwers during the rehabilitation process as their elbows are likely experiencing more stress than desired. Clinicians and coaches must be aware and may want to consider transitioning to more objective measures of effort during rehabilition.

Glenohumeral-Rotation-Deficits In High School, College, And Professional Baseball Pitchers With And Without An Mucl Injury

Glenohumeral-Rotation-Deficits In High School, College, And Professional Baseball Pitchers With And Without An Mucl Injury

Knee Pain - Baseball

HISTORY: A 16 year old high school hockey player and baseball pitcher noticed lateral knee pain and intermittent swelling for about 2 months prior to presentation. He does not recall any trauma or injury. He did have a viral URI and episode of strep pharyngitis several weeks before this started. He denies radiation of the pain. He does note some catching and locking sensation of the knee. He feels that his knee flexion is limited. He treated the knee with ice, ibuprofen, and acetaminophen through the season and was able to complete his baseball season prior to presenting to his PCP for evaluation. Because no definite etiology was identified in this visit, MRI was ordered, which showed complex loculated effusion, enlarged popliteal lymph nodes, and synovial thickening. There were no structural injuries appreciated. PHYSICAL EXAMINATION: Initial exam in the sports medicine clinic revealed tenderness at the lateral joint line and 1+ knee effusion. There was no erythema or warmth at the joint. He had full active and passive range of motion and full strength. Ligamentous testing was normal. DIFFERENTIAL DIAGNOSIS: PVNS Rheumatologic condition Lymphoma/Leukemia Lyme disease Traumatic hemarthrosis TEST AND RESULTS: Repeat MRI with additional views: Complex loculated effusion; Synovitis/synovial proliferation;No hemosiderin staining with blooming artifact Joint aspiration: 20 cc cloudy yellow synovial fluid; TNC 37,270, Neutrophils 73% Cytology: No malignant cells ANA: 1:80 homogeneous Rheumatoid Factor: Negative Lyme: Negative ESR: 9 CRP: 21.8 CBC: WBC 5.9, Hgb 15.5, Hct 45.4, Plt 287 FINAL WORKING DIAGNOSIS: Juvenile idiopathic arthritis (JIA) TREATMENT AND OUTCOMES: Referred to pediatric rheumatologist Bilateral knee aspiration and corticosteroid injection Prednisone taper Methotrexate therapy Check anti-CCP antibodies Referred to ophthalmology to rule out uveitis

Baseball Pitchers’ Perceived Effort Does Not Match Actual Measured Effort During a Structured Long-Toss Throwing Program

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

Current Workload Recommendations in Baseball Pitchers: A Systematic Review

Background: Several recommendations have been made regarding pitch counts and workload for baseball players of different levels, including Little League, high school, collegiate, and professional baseball. However, little consensus is found in the literature regarding the scientific basis for many of these recommendations. Purpose: The primary purpose of this study was to summarize the evidence regarding immediate and long-term musculoskeletal responses to increasing pitching workload in baseball pitchers of all levels. A secondary purpose of this review was to evaluate the extent to which workload influences injury and/or performance in baseball pitchers. Study Design: Systematic review. Methods: We performed a systematic search in accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for studies addressing physiologic and/or pathologic musculoskeletal changes in response to a quantifiable pitching workload. We included studies examining the effects of pitching workload on performance, injury rate, and musculoskeletal changes in Little League, high school, collegiate, and professional baseball players. Results: We identified 28 studies that met our inclusion and exclusion criteria: 16 studies regarding Little League and high school pitchers and 12 studies regarding collegiate and professional pitchers. The current evidence presented suggests that increased pitching workload may be associated with an increased risk of pain, injury, and arm fatigue in Little League and high school pitchers. However, little consensus was found in the literature regarding the association between pitching workload and physiologic or pathologic changes in collegiate and professional pitchers. Conclusion: Evidence, although limited, suggests the use of pitch counts to decrease injury rates and pain in Little League and high school baseball pitchers. However, further research must be performed to determine the appropriate number of pitches (or throws) for players of different ages. This systematic review reported conflicting evidence regarding the use of pitch counts in college and professional baseball. Future high-quality research is required to determine the role, if any, of pitch counts for collegiate and professional pitchers.

Glenohumeral rotation deficits in high school, college, and professional baseball pitchers with and without a medial ulnar collateral ligament injury

It is unclear how a glenohumeral internal rotation (IR) loss (GIRLoss), a glenohumeral external rotation (ER) gain (GERGain), or a total rotational motion (TRM) deficit (TRMD) predict medial ulnar collateral ligament (MUCL) injury risk among high school (HS), college (COLL), and professional (PRO) baseball pitchers with and without MUCL injury. We hypothesized that pitchers with MUCL injury would have more GIRLoss and TRMD compared with pitchers without MUCL injury, with no differences in IR, ER, TRM, GIRLoss, GERGain, and TRMD. The study equally divided 216 male HS, COLL, and PRO pitchers into the MUCL injury group (n = 108) and a control group (n = 108) without MUCL injury. The control group was matched with the MUCL injury group according to number, level of play, and age. Bilateral shoulder passive IR/ER was measured and GIRLoss, GERGain, TRM, and TRMD calculated. A 2-way analysis of variance (P < .05) was used to assess shoulder rotational differences among the 2 groups and 3 pitching levels. Compared with the control group, the MUCL injured group had more GIRLoss (21° ± 14° vs. 13° ± 8°; P < .001), GERGain (14° ± 9° vs. 10° ± 9°; P = .004), and TRMD (7° ± 13° vs. 3° ± 9°; P = .008). For all pitching levels, approximately 60% of pitchers in MUCL injury group had GIRLoss >18° compared with approximately 30% of those in the control group. Approximately 60% of pitchers in the MUCL injury group had TRMD >5° compared with 50% of pitchers in the control group. No differences were observed among HS, COLL, and PRO pitchers for GIRLoss (16° ± 12°, 17° ± 11°, 19° ± 13°, respectively; P = .131), GERGain (11° ± 9°, 11° ± 10°, 13° ± 10°, respectively; P = .171), TRMD (5° ± 11°, 6° ± 11°, 5° ± 14°, respectively; P = .711), and throwing shoulder ER (111° ± 10°, 111° ± 11°, 113° ± 9°, respectively; P = .427), IR (50° ± 11°, 49° ± 11°, 48° ± 10°, respectively; P = .121), and TRM (162° ± 14°, 160° ± 15°, 161° ± 14°, respectively; P = .770). Greater GIRLoss, GERGain, and TRMD in MUCL injured pitchers compared with uninjured pitchers implies these variables may be related to increased MUCL injury risk, especially because GIRLoss >18° and TRMD >5° demonstrate an increased MUCL injury risk. Shoulder rotational motion and deficits do not vary among HS, COLL, and PRO levels of pitchers.

Segmental Power Analysis of Sequential Body Motion and Elbow Valgus Loading During Baseball Pitching: Comparison Between Professional and High School Baseball Players.

Background:Pitching-related elbow injuries remain prevalent across all levels of baseball. Elbow valgus torque has been identified as a modifiable risk factor of injuries to the ulnar collateral ligament in skeletally mature pitchers.Purpose:To examine how segmental energy flow (power) influences elbow valgus torque and ball speed in professional versus high school baseball pitchers.Study Design:Descriptive laboratory study.Methods:A total of 16 professional pitchers (mean age, 21.9 ± 3.6 years) and 15 high school pitchers (mean age, 15.5 ± 1.1 years) participated in marker-based motion analysis of baseball pitching. Ball speed, maximum elbow valgus torque (MEV), temporal parameters, and mechanical power of the trunk, upper arm, and forearm were collected and compared using parametric statistical methods.Results:Professional pitchers threw with a higher ball speed (36.3 ± 2.9 m/s) compared with high school pitchers (30.4 ± 3.5 m/s) (P = .001), and MEV was greater in professional pitchers (71.3 ± 20.0 N·m) than in high school pitchers (50.7 ± 14.6 N·m) (P = .003). No significant difference in normalized MEV was found between groups (P = .497). Trunk rotation time, trunk power, and upper arm power combined to predict MEV (r = 0.823, P < .001), while trunk rotation time and trunk power were the only predictors of ball speed (r = 0.731, P < .001). There were significant differences between the professional and high school groups in the timing of maximum pelvis rotation velocity (42.9 ± 9.7% of the pitching cycle [%PC] vs 27.9 ± 23.4 %PC, respectively; P < .025), maximum trunk rotation (33 ± 16 %PC vs 2 ± 23 %PC, respectively; P = .001), and maximum shoulder internal rotation velocity (102.4 ± 8.9 %PC vs 93.0 ± 11.7 %PC, respectively; P = .017).Conclusion:The power of trunk motion plays a critical role in the development of elbow valgus torque and ball speed. Professional and high school pitchers do not differ in elbow torque relative to their respective size but appear to adopt different patterns of segmental motion.Clinical Relevance:Because trunk rotation supplies the power associated with MEV and ball speed, training methods aimed at core stabilization and flexibility may benefit professional and high school pitchers in reducing the injury risk and improving pitching performance.

Hip, Trunk, and Shoulder Rotational Range of Motion in Healthy Japanese Youth and High-school Baseball Pitchers

The rotational range of motion (ROM) in the upper extremities, trunk, and lower extremities is important for throwing motion. However, unlike for the shoulders, the differences relating to age and throwing-side in trunk and lower extremity ROMs in baseball pitchers are unknown. This study examined the effects of age and dominance on the ROMs of the trunk and upper and lower extremities. The study included 356 young baseball pitchers aged 9-17 years who participated in off-season baseball camps. The subjects comprised 155 youth pitchers (aged 9-14 years) and 201 high-school pitchers (aged 15-17 years) who were able to throw at full force without pain. The neck, shoulder, trunk, and hip rotational ROMs on the dominant and non-dominant side were measured by well-trained physical therapists. The differences between throwing sides and between age groups were examined using two-way analysis of variance. Shoulder external rotation on the dominant side was greater than that on the non-dominant side. Shoulder external and internal rotational ROMs were maintained regardless of age, whereas the trunk rotational ROM significantly increased with age. The effects of age and dominance on ROMs of the neck, trunk, and upper and lower extremities in Japanese youth and high-school baseball pitchers were clarified. These data could be used as a specific reference and as target values for the rehabilitation of throwing injuries in young athletes.

Relationship between the elbow joint valgus instability and forearm flexor muscle strength in high school pitchers with and without symptom.

Earlier reports describe forearm flexor muscles as active stabilizers of the elbow to valgus stress during throwing motion. Given high school pitchers' history of elbow symptoms, this study assesses its relation to elbow valgus joint instability and forearm flexor muscle strength. Ultrasound examination was made for 132 high school baseball pitchers with and without valgus stress of the medial aspect of the bilateral elbows. They had completed a self-administered questionnaire related to self-satisfaction score (0-100) for pitching performance and throwing-related elbow joint pain sustained during the prior year. Using a digital manual muscle strength meter, we examined the grip strength and muscle strength of the flexor carpi ulnaris (FCU). For participants with and without a history of elbow symptom, we compared differences of ulnohumeral joint space width with and without valgus stress and grip and FCU muscle strength. For ulnohumeral joint width difference with and without valgus stress, pitchers with an elbow symptom and those without elbow symptom history on the throwing side were not significantly different. No difference was found in the grip strength or FCU muscle strength of the throwing side for each group. Positive significant association was found between FCU muscle strength on the pitching side and the self-evaluation score for pitching performance ( r = 0.27, p = 0.002). However, no association was found between the elbow valgus instability and the forearm flexor muscle strength. FCU muscle strength might influence high school baseball pitching performance.

Effect of Fatigue on Medial Elbow Torque in Baseball Pitchers: A Simulated Game Analysis

Background: The incidence of overuse injury to the elbow among baseball pitchers continues to rise, despite extensive efforts at pitch count regulations and emphasis on proper throwing mechanics. Purpose: To determine if the medial elbow experiences increased torque levels as a baseball pitcher fatigues through the course of a simulated game. Study Design: Descriptive laboratory study. Methods: High school and collegiate baseball pitchers were recruited for this simulated game study. Each pitcher completed a simulated game consisting of 6 innings and a standardized pitching scheme of fastballs, curveballs, and changeups. In total, each pitcher threw 90 pitches. Fatigue was reported per inning with a visual analog scale, and pitch velocity was captured per pitch with a radar gun. Outcome measures were assessed with a validated mobile sensor and included medial elbow torque, arm speed, arm rotation, and arm slot. Linear and quadratic regression modeling was used to evaluate the relationship between pitcher fatigue and pitching kinematics. Results: A total of 11 pitchers (mean age, 17.6 years; range, 15-20 years) completed the study. Visual analog scale fatigue scores increased 0.72 points per inning pitched (P < .01, effect size = 0.64). Medial elbow torque also increased beyond inning 3, with an increase of 0.84 N·m each inning (P < .01, effect size = 0.08), while pitch velocity decreased (0.28 mph per inning, P < .01, effect size = 0.27). Fastballs generated the greatest amount of medial elbow torque (49.3 ± 1.4 N·m, P < .01, effect size = 0.24). There were no differences in arm rotation (P = .42) or arm speed (P = .80) as the game progressed. However, arm slot decreased with each successive inning (0.73° on average per inning, P = .03, effect size = 0.12). No adverse outcomes were noted with use of the mobile sensor. Conclusion: In this simulated game analysis, pitchers experienced increased fatigue after each successive inning. While the average pitch velocity declined with each successive inning, the torque on the medial elbow increased after inning 3. These findings signify a possible relationship between fatigue and injury risk.

Effects of weighted baseball throwing during warm-up on ball velocity and upper extremity muscle activation in baseball pitchers.

The objective of this study was to investigate the changes in the muscle activation of high school and college baseball pitchers during throwing of the ball with maximum effort (TBME) using a regular baseball (RB) subsequent to using a light baseball (LB), RB, and overweight baseball (OB) during warm-up (WU) and the resulting changes in the pitch velocity. The study aimed to use the findings in providing basic data for a training program designed to increase the pitch velocity of baseball pitchers. The study population consisted of 12 high school and college baseball players. The study measured and analyzed the upper extremity muscle activation and ball velocity in the stride, arm cocking, and acceleration phases during TBME using an RB subsequent to using an LB, RB, and OB during WU. During WU, the ball velocity was higher when pitching with an LB than with an RB or OB and when pitching with an RB than with an OB. However, there were no significant differences in the ball velocity when pitching with an RB during TBME. In conclusion, WU using weighted baseballs resulted in varying muscle activations, and although the velocity decreased when pitching with an OB, no difference was found during TBME using an RB. Therefore, it is believed that using weighted baseballs during WU does not have an effect on the ball velocity during TBME; future studies are needed on the effects through long-term training.

The Relationship Between the Push Off Ground Reaction Force and Ball Speed in High School Baseball Pitchers.

Oyama, S and Myers, JB. The relationship between the push off ground reaction force and ball speed in high school baseball pitchers. J Strength Cond Res 32(5): 1324-1328, 2018-Baseball pitching is a sequential movement that requires transfer of momentum from the lower extremity to the throwing arm. Therefore, the ground reaction force (GRF) during push off is suggested to play a role in production of ball speed. The purpose of this study was to investigate the correlation between GRF characteristics during push off and ball speed in high school baseball pitchers. A total of 52 pitchers performed fast pitches from an indoor pitching mound. A force plate embedded in an indoor mound was used to capture the push off GRF. The GRF characteristics (peak anterior, vertical, and resultant forces, vertical and resultant forces at the time of peak anterior GRF, and impulse produced by the anterior GRF) from the 3 fastest strike pitches from each pitcher were used for analyses. Spearman's rank correlation coefficients were used to describe the relationships between ball speed and the GRF characteristics. Ball speed was only weakly correlated with peak resultant force (ρ = 0.32, p = 0.02) and vertical (ρ = 0.45, p < 0.001) and resultant (ρ = 0.42, p = 0.002) forces at the time of peak anterior force. The ball speed was not correlated with other variables. The correlation between ball speed and push off force in high school pitchers was weak, especially when compared with what was reported for adult pitchers in other studies. Unlike for adult pitchers, higher push off force is only weakly correlated with ball velocity in high school pitchers, which suggests that training to better use body momentum may help high school pitchers improve ball speed.

Rate of Upper Extremity Injury in High School Baseball Pitchers Who Played Catcher as a Secondary Position

Many high school pitchers play another position after they have finished pitching for the day or on their rest days from pitching. Because of the cumulative demands on the arm, pitchers who also play catcher may have a greater risk of developing a throwing-related shoulder or elbow injury. To compare the rate of throwing-related upper extremity injuries between high school baseball pitchers who also played catcher as a secondary position and those who did not play catcher. Prospective cohort study. Field laboratory. A total of 384 male high school baseball pitchers were recruited from 51 high school teams. Pitchers who reported their secondary position as catcher were classified into the pitcher/catcher group and those who did not report playing catcher as a secondary position were classified into the other group. Participants completed a demographic questionnaire preseason and then athlete participation and injury status were tracked during the subsequent season. Athlete-exposures were monitored and the shoulder and elbow injury proportion rates were calculated. Athlete-exposures did not differ between groups ( P = .488). The pitcher/catcher group's risk of shoulder or elbow injury was 2.9 times greater than that of the other pitchers (15% versus 5%; injury proportion rate = 2.9; 95% confidence interval = 1.03, 8.12). Pitchers who reported also playing catcher were at a greater risk of sustaining a throwing-related shoulder or elbow injury than the other pitchers. These findings suggest that pitchers should consider not playing catcher as their secondary position in order to allow adequate time for recovery and to decrease their overall throwing load. Serial physical examinations of pitchers/catchers during the season may be useful in determining if their physical characteristics are changing during the season because of the cumulative throwing load.

Pain and Overuse in High School Baseball Pitchers During a Season

Pain and Overuse in High School Baseball Pitchers During a Season

The Relationship between the Mechanical Work of the Stride Leg for Knee and Hip and Joint Torque of the Shoulder in Junior High School Baseball Pitcher

The Relationship between the Mechanical Work of the Stride Leg for Knee and Hip and Joint Torque of the Shoulder in Junior High School Baseball Pitcher

Assessment of Elbow Torque and Other Parameters During the Pitching Motion: Comparison of Fastball, Curveball, and Change-up

To assess the precision of a new wearable device in detecting medial elbow torque during the pitching motion in competitive baseball pitchers and to determine the differences in torque across pitch types and thrower demographic characteristics. High school and collegiate baseball pitchers were recruited from August 1, 2016, to January 31, 2017, through direct request by athletic trainers and coaches. Body dimensions and throwing arm measurements of the participants were collected. The sensor was positioned directly over the medial elbow and pitchers were instructed to throw 8 fastballs, 8 curveballs, and 8 change-ups in a standard, randomized sequence. The sensor reported elbow torque, arm speed, arm slot, and shoulder rotation, whereas a radar gun measured peak ball velocity. Precision was calculated by measuring outlier rate, and mixed model regression analysis was performed to detect differences in throwing biomechanics among pitch types. In total, 37 competitive baseball pitchers were included in the study. The device had a precision of 96.9% for fastballs, 96.9% for curveballs, and 97.9% for change-ups. The device was sensitive enough to distinguish pitches according to elbow torque, arm speed, arm slot, and shoulder rotation. Fastballs caused the greatest relative torque across the medial elbow (average= 45.56Nm), compared with change-ups (43.77Nm; P= .006) and curveballs (43.83Nm; P= .01). Ball velocity contributed most to medial elbow torque (P= .003), followed by elbow circumference (P= .021), where smaller elbow circumference predicted greater medial elbow torque. The sensor is a precise and reproducible device for measuring torque across the medial elbow, as well as additional parameters of arm speed, arm slot, and shoulder rotation. Torque was significantly relatively higher in fastballs than curveballs and change-ups. Level III, comparative study.

The Effect of Glenohumeral Internal Rotation Deficit Rehabilitation Training on Exercise Performance &amp; Body Shape Displacement in High-School Baseball Pitchers

The Effect of Glenohumeral Internal Rotation Deficit Rehabilitation Training on Exercise Performance &amp; Body Shape Displacement in High-School Baseball Pitchers

Generalized Joint Hyper Mobility is not Associated with the Development of Overuse Arm Injuries in Adolescent Baseball Pitchers

Objectives:Generalized joint hypermobility is theorized as a risk factor for joint injury in sport. However, there are no studies demonstrating generalized joint hypermobility and upper extremity overuse injury. Therefore the purpose of this study was to prospectively examine generalized joint hypermobility using the Beighton Scale and upper extremity overuse injuries in high school baseball pitchers.Methods:Healthy high school baseball pitchers (n=167) who were participating in all team activities were included in the study. The players averaged 15.8 ± 1.2 y.o., weighed 72.3 ± 13.0 kg, and measured 165.0 ± 43.8 cm in height. They were assessed during the preseason for joint hypermobility using the 9-point Beighton scale. From the first official day of practice until the last regular or postseason competition, all athletes who reported pain or injury to their coach were referred to the certified athletic trainer (AT) at their school for evaluation and classification of each potential injury. Verified overuse injuries were tracked and documented in the Athletic Trainer System (ATS) by the schools AT. The ATS system was also used to identify players with a history of upper extremity injuries. Generalized joint hypermobility was defined as modified Beighton scale scores ≥ 4. Separate one-way ANOVA’s were used to determine the mean Beighton scores between groups. A chi square analysis was used to assess the frequency of overuse injuries in those with a Beighton score of ≥ 4 and those with elbow hyperlaxity. (α=0.05)Results:The prevalence of generalized hypermobility in this cohort was 35.3%. Of those pitchers sustaining a time-loss overuse injury (n=23), only 4 presented with a Beighton score ≤ 4. The average Beighton score in those sustaining a time-loss overuse injury was similar to the Beighton score of those pitchers remaining healthy (2.9 ± 2.1 vs. 2.5 ± 2.1; P=0.59), respectively. There was no difference in the Beighton score of pitchers with a history previous injury when compared to pitchers without a history of injury (2.7 ± 2.1 vs. 2.6 ± 2.0; p=0.75), respectively. Injured pitchers with a Beighton score ≥ 4 presented with similar time-loss as pitchers with a lower Beighton score (P= 0.93). The relative risk of injury for a pitcher with a Beighton score ≥ 4 was similar to pitchers with a lower Beighton score (RR= 1.0, 95% CI: .54-1.8). Hyperlaxity at the elbow was not associated with elbow overuse injury (P=0.29).Conclusion:Generalized joint hypermobility, as defined by a Beighton score ≥ 4 or elbow hyperlaxity, did not increase the risk of developing an upper extremity overuse injury in this cohort of adolescent baseball pitchers. Additionally, injured pitchers with higher Beighton scores returned to participation within a similar timeframe as those with less generalized joint hypermobility.