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The Effect of Varying Ball Weights on Pitching Kinetics and Kinematics in Youth Baseball Players

IRB Number: 2023-0988

December 07, 2023

Institutional Review Board, Hospital for Special Surgery

The safety of our participants is our top priority. The trial/study is approved and periodically reviewed by the Institutional Review Board (IRB), which includes doctors, administrators, ethicists, and members of the general public. The safety of clinical trials is reviewed by the U.S. Food and Drug Administration.

Before enrolling in a clinical trial or research study, the investigator will explain the purpose of the trial/study, its expected benefits, any possible risks or side effects, and what your role will be. If you want to join the trial/study, you must sign informed consent documents. You can leave a trial/study at any time without penalty.

For further information, see Understanding Clinical Trials/Research Studies.

Principal Investigator

Andreas Kontaxis, PhD


Joshua S. Dines, MD
Kathryn D. McElheny, MD   
James B. Carr II, MD
Terrance Sgroi PT, DPT, SCS, MTC
Robert Andrews PT, DPT, SCS
Jessica Rios     
Stephen Bartalini    
Silvia Zanini    
David Iodice  
Matthew Fury
Dylan Bennett 


The purpose of this study is to determine the effect of baseball weight on the pitching motion and joint forces in youth baseball pitchers. The study will also investigate how the baseball weight affects grip strength, which is also correlated with injury.

The study will recruit two cohorts of 20 youth male baseball players each (ages 7-9 and 10-12).  Each participant will complete 1 visit (visit will take 2 hours).

Inclusion/Exclusion Criteria


  • Amateur male baseball players of ages 7-12
  • Minimum of 1 season of baseball experience


  • History of shoulder or elbow injury requiring surgery or cessation from throwing
  • Players with a history of shoulder or elbow pain over the past 6 months
  • Players with a history of lower extremity or back pain over the past of 6 months
  • Players who have pitched in a competitive game within 4 days of anticipated testing
  • Players unwilling to adhere to 2 days of rest from competitive pitching after laboratory testing

Contact Information

Andreas Kontaxis, PhD