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  • 7/13/2013 updated link for ASMI position statement
  • 3/1/2011 unless noted

Studies About Baseball and Fastpitch Pitching and Injuries

We have accumulated a list of important studies related to pitching and related injuries all in one handy reference.


The latest studies indicate that, despite previous "common knowledge" and "studies" from as far back as the 1950s, "curveballs are not the problem" when it comes to baseball pitching injuries - "overuse is".
"I'm not saying, everyone throw the curveball. I'm saying, if we're going to prevent injuries, change the focus. We should be looking at overuse."

- Dr. Glenn Fleisig, American Sports Medicine Institute
Fleisig 2006: The self-described curveball does not produce more elbow torque than the self-described fastball of college pitchers

Nissen 2009: The self-described curveball produces less elbow torque than the self-described fastball of high school pitchers

Dun 2008: The self-described curveball produces less elbow torque than the self-described fastball of youth pitchers

Pitch Counts and Overuse

Technique Studies

  • Center for Human Performance Study dated 2009 Correlation of Throwing Mechanics With Elbow Valgus Load in Adult Baseball Pitchers [3/22/2011]
    Players who initiated trunk rotation before front-foot contact had significantly higher elbow valgus torques than did those who rotated afterward.

    This finding concurs with previously reported findings that showed reduced shoulder rotation torques in pitchers with late trunk rotation

    Fourteen pitchers [out of 69 tested] displayed a sidearm delivery and had significantly higher elbow valgus torques than did those with an overhand arm slot position.

    ...in sidearm deliveries, the whipping action that results from early trunk rotation may exacerbate higher valgus loads as the horizontally placed arm lags behind into ball release.
  • Chiang and Tang X-factor study in 2005 Rotation Characteristics of the Shoulder, Torso, and Pelvis During Pitching for Taiwan Elite and Sub-elite Collegiate Baseball Pitchers
    Elite pitchers exhibited proper sequential movement of the entire body, with a greater angular velocity of twist and flexion motions, and larger X-factors [stretch between shoulder and pelvis]. They also pitched faster, and the net torques at the shoulder before ball release, as calculated by inverse dynamics, were higher. Such proper mechanics also delay the onset of fatigue, leading to more consistent performance. In the long term, overuse injuries, which may result from cumulative microtrauma, may be reduced through utilizing aforementioned techniques.
  • ASMI report 2007 Comparison of High Velocity and Low Velocity Pitch Deliveries [3/2/2011]
    A pitcher with increased shoulder external rotation, faster pelvis and upper trunk rotation, and greater front knee stabilization and extension will throw with greater ball velocity.

    Improved timing to maximize arm velocity closer to the time of ball release will also help ball velocity.

    Increased torque and force produced at both the shoulder and elbow will also lead to greater ball velocity. [this sounds like bad logic to us]



  • ASMI Throwers 10 exercises [3/31/2011]
    most trunk training exercises generally used in strength and conditioning programs would demonstrate sufficient differentiated trunk rotation, but an emphasis in these exercises should include the production of maximum range of motion. In addition, generating more energy in the trunk may decrease the risk of injury by decreasing the relative contribution of shoulder and elbow musculature that would demanded to compensate for the lack of optimal lower extremity involvement