Illinois Hammerheads Baseball

How Weighted Baseballs Cause Injuries


If you are looking to start using weighted baseball, please take a look at this video.

Illinois Hammerheads Position on the Use of Weighted Ball Throwing Programs:

The use of weighted baseballs to help players throw harder is nothing new.  They have been around for a while.  We do not use weighted baseballs in our program.  There are some of our older guys who choose to do some weighted ball training on their own and we don’t stop them from doing it if they come in here on their own to train.  However, for our travel baseball teams, weighted baseballs ARE NOT part of our routine.


What We Know (The Positives)

They work.  Many programs that do weighted ball throwing programs will see 2 to 4 mph velocity gains.  Some kids gain more, some less.


What We Know (The Negatives)

There haven’t been enough studies out there, but now that we are starting to see some studies done, it is helping us make better decisions for training our players.  Dan Blewett and ASMI did a study and they followed some of the players through the program to see what happened as far as injuries.  The research suggests a correlation between major arm injuries (I.e. torn UCL, torn Lats, growth plate fractures) and training with weighted baseballs.

As more studies come out, we will continue to add to this page.


Who is ASMI?

American Sports Medicine Institute

The American Sports Medicine Institute is a sports medicine research and education foundation located in Birmingham, Alabama. ASMI was founded in 1987 by renowned orthopaedic surgeon Dr. James R. Andrews. The mission of ASMI is to improve the understanding, prevention and treatment of sports-related injuries through the research conducted in its biomechanics laboratory and skills lab. ASMI is the nation’s largest accredited educator of sports medicine physicians.


Who is Dan Blewett

Dan Blewett

Dan Blewett is a recently retired professional baseball player who conducted research on the efficacy of weighted balls and their correlation to arm injuries following the completion of weighted ball throwing programs with ASMI.