• Baseball is a generally safe sport; however, acute and chronic injuries do occur. For pitchers, the majority of these injuries involve overuse injuries of the elbow and shoulder.1-3

• Overall, youth athletes are more susceptible to overuse injuries of the shoulder and elbow due to incomplete bone ossification, overloading stresses placed on the joints from full-speed throwing motions, and general instability of the glenohumeral joint with fatigue.1,4 In turn, this places pitchers especially at risk of injury.5

• Currently, there is no one single risk factor increasing the risk shoulder or elbow injury. However, in adolescent baseball, rising pitch counts and specific pitch types influence risk of injury, but how much is still under investigation.

• Does pitch count /type increase the risk of shoulder and/or elbow injuries in adolescent baseball pitchers?

• Articles examining the influence of pitch count/type on shoulder/elbow injuries were identified from the following electronic databases from January 2000 through November 2013:

1. PubMed (www.pubmed.gov)2. Cumulative Index to Nursing and Allied Health Literature

(CINAHL) 3. Science Direct4. MEDLINE• Key terms used included:• “adolescent and baseball”• “adolescent and pitch count or pitch type”• “shoulder or elbow and injuries and adolescent”

• Studies could be either full reports or abstracts meeting the inclusion criteria in table 1.

The Influence of Pitch Count and Type on Elbow and Shoulder Injuries in Adolescent Baseball Pitchers: A Systematic Review

Nicole R. Miela, Julie C. Jamrog, Mitchell T. Irwin, & David C. Berry, PhD, AT, ATC

Saginaw Valley State University, University Center, MI

• Three reviewers independently assessed (Table 2) each report according to the Strengthening in the Reporting of Observational Studies in Epidemiology (STROBE) and Physiotherapy Evidence Database (PEDro) scales.

• Three articles were observational studies.• Average PEDro score for one clinical trial was 5.33±0.94.• Olsen et al5 examined adolescent pitchers who underwent

shoulder or elbow surgery and age-matched controls and found:• Pitches per appearance yielded significance (p <0.001)

for shoulder (93.16±15.2 pitches) and elbow injuries (85.2 ±23.8).

• Pitches per year showed significance (p <0.001) for both shoulder and elbow injuries (2608.4 ± 1587.3, 2458.6 ± 1321.3).

• A controlled clinical trial6 to determine differences between the fastball, curveball, and change-up found:• The fastball produced the greatest values for elbow and

shoulder proximal force (461.9 ±163.2 N, 465.6 ±169.9 N), p <0.01.

• Data suggests that increased pitch counts per season and game increases the occurrence of elbow and shoulder pain, respectively.

• The fastball appears to place the most stress on both the elbow and shoulder, while the sinker is more influential on the elbow. This sheds light on what used to be simply controversy regarding injury risk of certain pitches.9

• Pitching through pain and fatigue is NOT recommended as it indicates an increased potential for overuse injuries (OR 36.18, 95% CI 5.92-221.22).5,10

• Rates of biomechanical development vary individually. These variances coupled with age-ranged recommendations makes pinpointing when a pitcher is able to throw a certain pitch difficult to determine.

• Increased awareness of the influence of pitch count and type to coaches, parents, and athletes can be facilitated by athletic trainers.

• Athletic trainers can promote the use of pitch tracking and to identify athletes most at risk of injury.

• Through efficient pitch tracking and risk identification, athletic trainers can work with the athlete, coaches, and parents to determine the best course of injury prevention or management for the athlete.

• Increased pitches per season yielded increased elbow pain, while increased pitches per game yielded increased shoulder pain. The fastball, slider, and sinker led to increased joint pain as well. Developmental variances among youth inhibits definite conclusions concerning the degree of influence pitch count/type holds on injury rates.

1. Rice SG, Congeni JA. Baseball and softball. Pediatrics. 2012;129(3):e842-56.2. American Academy of Pediatrics Committee on Sports Medicine and Fitness. Risk of injury from baseball and softball in children.

Pediatrics. 2001; 107:782-784.3. Rizio L, Uribe JW. Overuse injuries of the upper extremity in baseball. Clin Sports Med. 2001; 20:453-468.4. Dalton SE. Overuse injuries in adolescent athletes. Sports Med. 1992;13(1):58-70.5. Olsen SJ, et al. Risk factors for shoulder and elbow injuries in adolescent baseball pitchers. Am J Sports Med. 2006;34(6):905-12.6. Dun S, et al. A biomechanical comparison of youth baseball pitches: is the curveball potentially harmful?. Am J Sports Med.

2008;36(4):686-92.7. Lyman S, et al. Longitudinal study of elbow and shoulder pain in youth baseball pitchers. Med Sci Sports Exerc. 2001;33(11):1803-

10.8. Lyman S, et al. Effect of pitch type, pitch count, and pitching mechanics on risk of elbow and shoulder pain in youth baseball

pitchers. Am J Sports Med. 2002;30(4):463-8.9. Fleisig GS, et al. Kinetic comparison among the fastball, curveball, change-up, and slider in collegiate baseball pitchers. Am J Sports

Med. 2006;34:423-430.10. McLeod TCV, et al. National Athletic Trainers’ Association position statement: prevention of pediatric overuse injuries.

http://www.nata.org/sites/default/files/Pediatric-Overuse-Injuries.pdf. J Athl Train. 2011;46(2):206-220. Published April 2011. Accessed November 22, 2013.

Crystal M. Lange College of Health and

Human Services

Introduction

Clinical Question/Objective

Discussion

Clinical Application

Conclusion

References

Data Source

Data Extraction

Data Synthesis

Table 1. Inclusion Criteria.1. Peer-reviewed cohort, descriptive epidemiology, case

control, cross-sectional, or controlled clinical trial

2. Full reports or abstracts published in English

3. Involved adolescents 13-18 years of age 4. Available abstract5. Outcomes measuring the influence of pitch count/type

on shoulder and/or elbow injuries

Table 2. Data of Interest

1. Methods of observation/trial and descriptive data

2. Subjects and group divisions

3. Odds ratios and 95% confidence intervals referring to influence of pitch count/type on shoulder/elbow injuries

Data Source

Lyman et al.5

Cumulative Pitches Elbow Pain OR(95% CI)

P Shoulder Pain OR(95% CI)

P

<300 Referent --- Referent <0.01300-599 0.54 (0.32, 0.92) 0.02 0.40 (0.24, 0.65)

≥600 2.07 (0.68, 6.26) 0.20 0.13 (0.01, 1.10)Age (M=10.8 years)

<10 yr Referent 0.02 Referent 0.1310 yr 1.66 (0.71, 3.88) 0.55 (0.29, 1.03)11 yr 2.60 (0.99, 6.81) 0.68 (0.28, 1.65)

≥12 yr 2.91 (1.14, 7.41) 0.41 (0.14, 1.15)

• The key findings of Lyman et al.7 are presented in table 3.Table 3. Elbow and Shoulder Pain in Youth Baseball Pitchers

• Lyman et al’s8 effects of pitch type/count are in table 4. Table 4. Effect of Pitch Type, Pitch Count, and Pitching Mechanics

Season Pitches to Date Elbow OR P Shoulder OR P1-200 Referent <0.01 Referent <0.01

201-400 1.63 1.65401-600 2.81 2.34601-800 3.34 2.90

800+ 2.61 3.29Game Pitch Counts

9-10 yo 1-24 Referent 0.67 Referent 0.0125-49 1.20 0.9750-74 1.40 1.1175-99 0.91 1.32100+ 1.33 2.01

11-12 yo 1-24 Referent 0.60 Referent 0.9425-49 0.84 0.9850-74 0.83 1.1075-99 1.30 1.14100+ 0.87 0.76

13-14 yo 1-24 Referent 0.06 Referent 0.0625-49 1.12 1.5150-74 1.38 1.6575-99 1.59 2.17100+ 2.22 2.15

Pitch Type and AgeChange-up 9-10 yo 1.41 0.36 0.65 0.20

11-12 yo 0.59 0.14 0.67 0.26 13-14 yo 0.69 0.37 1.10 0.83

Curveball 9-10 yo 1.35 0.44 1.62 0.16 11-12 yo 1.06 0.86 1.54 0.22 13-14 yo 0.73 0.49 1.47 0.41

Slider 9-10 yo 1.57 0.39 1.14 0.79 11-12 yo 0.74 0.61 3.38 0.02 13-14 yo 3.49 <0.01 1.80 0.17