My son is 11 and plays competitive baseball. He has recently taken a fancy to throwing sidearm, dropping his shoulder to throw once in a while when pitching (he is not a regular pitcher) and while playing outfield and 3B.
Besides the obvious inefficiencies of sidearm throwing in terms of accuracy, it just looks awkward and not in harmony with the natural rotation of his shoulder. Are there health considerations. I believe he is dropping his arm because he thinks he gets mor distance out of the throw, so he is definitely stressing his arm when trying to get that extra distance ont he throw....
Post by Glenn Fleisig, Ph.D. on Jun 5, 2008 8:41:11 GMT -6
You are correct that sidearm throwing is an ineffective way to throw for an 11-year-old positional player. Even if your son has aspirations in pitching, it is important for him to develop standard overhand throwing mechanics first.
Our numerous biomechanical studies have shown that successful baseball players throw around the 3/4-arm slot. In other words, when you look at a righthanded player throwing at you, the arm should be between "9 o'clock" and "12 o'clock" position at the instant of ball release.
In addition to performance, there is also a safety issue. Because of shoulder anatomy, it is safest to throw the ball with about 90 degrees of shoulder "abduction". What that means is that from the time the arm is cocked back until the ball is thrown, the throwing elbow should be in line with the two shoulders. Make a video of your son throwing the ball towards the camera. Then look at the video frame of ball release. Draw a line through both shoulders on this picture and see if the throwing elbow is on this line. If the elbow is more than 10 degrees above or below this line, your son has an increased risk of a shoulder impingement injury from repetitive throwing.
Glenn, Is "sidearm" throwing more determined by the angle of the elbow joint than the angle of shoulder abduction? Shoulder abduction angle being the angle between the trunck and the upper arm? For example my son throws "sidearm" his upper arm is about a 90 degree angle to his trunk witha straight line across the upper arm and through the shoulders however his elbow joint is probably a 110-120 degree angle. My wife throws with a 90 degree angle at both shoulder abduction and the elbow joint. These mechanics give my son an angled spin on the ball while my wife has 6-12 back spin. Is the current thought that these mechanics are the individual's natural mechanics and should not be changed? My son was releasing the ball at 11 o'clock but a coach noticed he has dropping his glove side shoulder to get his hand at 11oclock and had him level his shoulders now his hand is at 10 o'clock not change int he joint angles.