According to their website, 60 percent of high school baseball pitchers suffer serious arm injuries. Even worse, over half of these players cannot return or have limited careers.

"So just put your arm out, palm up," O'Connell says to a college-age pitcher. O'Connell slides the sleeve onto the player's throwing arm so it stretches from midforearm to just under the shoulder.

But Motus has found that pitchers sometimes drop their arm slot–from overhand toward sidearm–by as much as 19% during games. This change happens slowly, however.

Motus Global has a sleeve armed with technology to measure how much torque is placed on the arm on each pitch. By Matt Snyder Dec 8, 2014 at 11:14 am ET • 2 min read ...

For years, starting big-league pitchers have struggled with a vexing problem — how to keep their arms warm during down periods without sweating under bulky jackets. Under Armour, which is try… ...

Schwartz: Arm Sleeves Have Become Very Popular Among Athletes October 20, 2015 / 8:00 AM EDT / CBS New York By Peter Schwartz » More Columns ...

“Inside, it has a little 3D sensor that measures everything about a pitcher’s motion. One of the biggest things we measure is the torque on their UCL in addition to their arm speed.