1. Examining the relationship between different pitching mechanics and throwing injuries
Zachary McCarthy Masters in Athletic Training Student
Faculty Mentor: Valerie Moody

2. Overview Literature Review
Focusing on the 6 phases of the throwing cycle
Throwing injuries associated with each phase
Different types of throwing injuries
Recommendations to prevent injury

3. Phases of Throwing Cycle
6 phases of the throwing cycle
Wind-up (WU)
Early Cocking (EC)
Late Cocking (LC)
Acceleration (AC)
Deceleration (DC)
Follow-Through (FT)

4. Common Injuries during Throwing Cycle
Investigated baseball pitching kinematics & joint loads during each phase of the throwing cycle.
Each phase places different stresses on the tissues in the body
Found no significant stresses or injuries associated with the WU or FT
Early Cocking
Anterior Instability & Posterior Impingement
Late Cocking
SLAP lesions, subacromial impingement, UCL sprain, medial epicondylitis
Acceleration
Biceps tendinopathy, rotator cuff strain, UCL sprain
Deceleration
Biceps tendinopathy, SLAP lesion, subacromial impingement
Oyama S. Baseball pitching kinematics, joint loads, and injury prevention. Journal of Sport and Health Science. 2012;1(2):80-91.

5. Oyama S. Baseball pitching kinematics, joint loads, and injury prevention. Journal of Sport and Health Science. 2012;1(2):80-91.

6. Common Throwing Injuries
UCL pathology
Occurrences of UCL tears have increased over the past 10 years
= 16 per season / = 26 per season
UCL reconstructions are increasing in high school baseball
Petty et al. indicated doubling rate compared to little league
Less common in adolescents
SLAP tears
Late Cocking phase is associated with SLAP
Little League Shoulder
Overload injury to the proximal humeral epiphysis
Shanley E, Thigpen C. Throwing Injuries in the Adolescent Athlete. The International Journal of Sports Physical Therapy. 2013;8(5):

7. UCL Injuries
Anterior Band is primary soft tissue stabilizer for valgus stress
~ 64 Nm of valgus torque through elbow is produced every pitch
Kinetic Chain produces 64 Nm of varus torque before ER
Equivalent to holding baseballs
Ultimate valgus torque of the UCL is ~33 Nm to failure
Every pitch the UCL experiences maximum torque which can lead to failure
Ciccotti M, Atanda A, Nazarian L, Dodson C, Holmes L, Cohen S. Stress Sonography of the Ulnar Collateral Ligament of the Elbow in Professional Baseball Pitchers. The American Journal of Sports Medicine. 2014;42(3):

8. SLAP Tears Has been implicated this can be caused by overuse
Position of LC increases the likely hood of the “peel back” mechanism of a SLAP lesion
Mihata et al.
Weak or fatigued subscapularis may contribute to the peel back mechanism
Wolf B, Wolstenholme K. Throwing injuries: biomechanics, injury mechanisms and rehabilitation. Current Orthopaedic Practice. 2010;21(5):

9. Little League Shoulder
Proximal humeral epiphysiolysis
Commonly seen in adolescents ( yrs)
Seen in pitchers who have thrown or pitched in high quantity
Similar to Salter-Harris injury
After symptoms disperse kids who are experiencing LLS had continuing widening of the proximal epiphysis
Zaremski J, Krabak B. Shoulder Injuries in the Skeletally Immature Baseball Pitcher and Recommendations for the Prevention of Injury. PM&R. 2012;4(7):
Heyworth B, Kramer D, Martin D, Micheli L, Kocher M, Bae D. Trends in the Presentation, Management, and Outcomes of Little League Shoulder. The American Journal of Sports Medicine. 2016;44(6):

10. Demographic Commonly Impacted by Injury Playing Baseball
Majority of the 11.5 million athletes playing baseball in the U.S compete at high school level
130,000 high school baseball injuries
More than 17% were shoulder injuries
Adolescent to high school are affected more than MLB
Epiphyseal plates don’t completely ossify until late teens
Glenoid, clavicle, proximal humerus = yrs, yrs, yrs respectively
Zaremski J, Krabak B. Shoulder Injuries in the Skeletally Immature Baseball Pitcher and Recommendations for the Prevention of Injury. PM&R. 2012;4(7):

11. Relationship between Pitch Type and Injuries Sustained
Analyzed pitch type as well
Fastball
No significant finding
Curveball
52% increase in shoulder pain
Slider
Overall an 86% risk of elbow pain when throwing
Specifically age group
Changeup
12% reduction in risk of elbow pain and a 29% reduction of shoulder pain
Over 400 potential pitchers were analyzed (age 9-13)
Analyzed fatigue first
Found that 75 pitches or more increased odds of shoulder injury 2 fold
Not as significant for elbow injury
Lyman S, Fleisig G, Andrews J, Osinski E. Effect of Pitch Type, Pitch Count, and Pitching Mechanics on Risk of Elbow and Shoulder Pain in Youth Baseball Pitchers. The American Journal of Sports Medicine. 2002;30(4):

12. Other Risk Factors for Injury
Focused on trunk rotation of adolescent pitchers compared to mature pitchers
Due to lack of hip total rotation
Adolescents initiated trunk rotation earlier
Hypothesized that this causes anterior instability
Increased valgus stress on UCL
Glenohumeral internal rotation deficit (GIRD)
10-17° of internal rotation deficit
Shown to lead to SLAP and an increase in UCL tears
Hibberd et al.
47 high school pitchers
40 (85%) have GIRD
Keeley D, Hackett T, Keirns M, Sabick M, Torry M. A Biomechanical Analysis of Youth Pitching Mechanics. Journal of Pediatric Orthopaedics. 2008;28(4):
Hibberd E, Shutt C, Oyama S, Blackburn J, Myers J. Physical contributors to glenohumeral internal rotation deficit in high school baseball players. Journal of Sport and Health Science. 2015;4(3):

13. Recommendations to Decrease Risk of Injury
Specific Exercises
Core strengthening
Shoulder
Lower Body
Balancing exercises
Improves KC control
Proper education
Signs of Fatigue
Pitcher’s mechanics
General knowledge of the 6 cycles
Pitch Count
Limiting adolescents to 75 pitches per outing
Little League Baseball has begun this
Type of Pitch
No curveballs or sliders
Try to throw low and force ground balls

14. Specific Exercises Thrower’s Ten Program Kinetic Chain Control
Single leg squat with twist
Lateral lunge to balance
Lower extremity stretching
Shoulder Exercises
Scapular wall slides
I’s, Y’s, T’s
Sleeper, Overhead, Crossover Stretch
Core Exercises
Bird Dogs to crunch
Forward & Slide Planks
Lumberjacks

15. Clinical Bottom Line
The time is now to teach adolescent pitchers how to properly pitch.
The combination of biomechanics, coaching, and exercise needs to be used to keep kids healthy for their entire baseball career.
Keep this sport great again

16. Questions??
THANKS FOR COMING! 

17. References
Oyama S. Baseball pitching kinematics, joint loads, and injury prevention. Journal of Sport and Health Science ;1(2):80-91.
Shanley E, Thigpen C. Throwing Injuries in the Adolescent Athlete. The International Journal of Sports Physical Therapy ;8(5):
Ciccotti M, Atanda A, Nazarian L, Dodson C, Holmes L, Cohen S. Stress Sonography of the Ulnar Collateral Ligament of the Elbow in Professional Baseball Pitchers. The American Journal of Sports Medicine. 2014;42(3):
Wolf B, Wolstenholme K. Throwing injuries: biomechanics, injury mechanisms and rehabilitation. Current Orthopaedic Practice. 2010;21(5):
Zaremski J, Krabak B. Shoulder Injuries in the Skeletally Immature Baseball Pitcher and Recommendations for the Prevention of Injury. PM&R. 2012;4(7):
Heyworth B, Kramer D, Martin D, Micheli L, Kocher M, Bae D. Trends in the Presentation, Management, and Outcomes of Little League Shoulder. The American Journal of Sports Medicine. 2016;44(6):
Lyman S, Fleisig G, Andrews J, Osinski E. Effect of Pitch Type, Pitch Count, and Pitching Mechanics on Risk of Elbow and Shoulder Pain in Youth Baseball Pitchers. The American Journal of Sports Medicine. 2002;30(4):
Keeley D, Hackett T, Keirns M, Sabick M, Torry M. A Biomechanical Analysis of Youth Pitching Mechanics. Journal of Pediatric Orthopaedics. 2008;28(4):
Hibberd E, Shutt C, Oyama S, Blackburn J, Myers J. Physical contributors to glenohumeral internal rotation deficit in high school baseball players. Journal of Sport and Health Science. 2015;4(3):