Arm Action


Pitchers have been told for years that they need to be long, loose, and "whippy" with their arm. The belief is if the arm action is short and compact they'll push the ball or lose power. While pitchers do not NEED to be quick with their actions, efficiency should still be the ultimate goal.  While throwing and the arm action associated with it is something that even toddlers do, it is the most over-coached part of baseball. The long and short of it is (that may have been a pun), whatever can be timed up most often is the right “length” of an arm action.

For simplicity’s sake, let’s break the arm action down into four phases: Arm swing, Final Connection, Launch, and Deceleration. Arm swing is referring to the time from hand break until the front foot hits the ground.  Final connection refers to the position of the arm at front foot strike. Launch is essentially when the arm unwinds and releases the ball. The Deceleration phase is then from release until the arm comes to a complete stop. In every throw, each phase exists. However, the only one that we choose to directly isolate is deceleration.  Everyone from eight-year-olds to our professional clients do deceleration drills every day. It is commonly overlooked, but, in our experience, a large majority of arm pain can be eliminated by cleaning up the deceleration phase.

Each phase will be affected by the phase before it and can affect the phase after it.  While we do not believe in a one-size-fits-all approach, we do have certain parameters for each and they are evaluated based on how they all sync together.

If you are a coach evaluating arm action, I strongly encourage you to get slow-motion video from the open side to look at arm action and even compare it to a big leaguer’s arm action. A large majority of video of pitchers is from the center-field camera, but this view is insufficient in evaluating mechanics because you can really only see side-to-side and one can lose reference of what is happening front to back.

Arm Swing

The timing of the hand break is critical. If the hands break too early, there is time for inefficient movement, and if it is too late the hand may not be up in time. To put it into words, we want the body to move away from the arm as opposed to the arm being thrown away from the body.  Often times we see athletes giving themselves too much time or really trying to reach back for extra velocity, as a result we will try to speed up the body moving toward the target to limit unnecessary arm movement. This phase is mainly a feel thing so eliminating time is highly effective because it forces the body to find it’s most efficient path. Reaching back for a little extra is a common phrase, but actually reaching away from the body just makes being on time at foot strike more difficult.  Being super short in this phase works well for some, but is not something that works for everyone. The inverted W (driving the elbows back and up) has become popular as a major contributor to Tommy John, while we now believe it is more of a timing issue we will not address this type of move unless there is shoulder or elbow pain and as long as it is not still present at front foot strike.

Final Connection

The position of the arm at foot strike is the real money-maker of a delivery. The hand needs to be “up” above the shoulder, even to or inside of 90 degrees, with the elbow just below the shoulder.  For many years people taught that the fingers need to be on top of the ball and the ball pointing to second base, however this puts the forearm in a position where it will be forced to turn off the muscles that protect the UCL to throw. Let the hand be neutral or even pointed toward the thrower. This phase is critical because it will dictate how the arm unfolds and launches. The rotation of the shoulders creates centripetal force which will drive the hand away from the body. If at foot strike the hand is already way outside of 90 degrees this launch could way too early. Adjustments to final connection can be done using a conveniently named connection ball, which creates feel for connected positions.  While in training this may look like shorting the arm action it is simply used to create feel for efficiency and provide feedback of if the athlete was connected through rotation.


As the shoulders rotate, the arm will lay back into external rotation and then begin to unfold.  This unfolding is a result of the shoulder internally rotating and the hand continuing to drive away from he body. THIS WILL ALL TAKE PLACE AS A RESULT OF WHAT THE BODY IS DOING. If this happens independently of the body, power, health, and maximum effectiveness will be greatly lessened.  Many have been taught to reach out toward the target, but this cannot happen independently. The throwing side hip and shoulder should be rotating past the glove side hip and shoulder driving the hand toward the target. Trevor Bauer recently referred to it on MLB Network as throwing a dart and I completely agree. The hand can make fine tuned adjustments right at the end, but it should not be the primary driver. While the launch phase is an easy one to diagnose and correct, a large majority of issues are a result of previous inefficiency, work backward first.


The ball is gone. If launch happened sequentially, the hand should be in front of the body with the throwing side rotated past the glove side. The first part of this phase is the forearm pronating (thumb down) immediately after ball release turning off the biceps. If the biceps stays active it will pull on what is above (shoulder) and below (elbow), turn it off. Many say that pronation is natural, but if a thrower only focuses on finishing with the fingers they may prevent pronation from occurring. Secondly, we want both shoulders to continue to rotate so that the throwing shoulder finishes on the target. This is not to be confused with rolling the throwing shoulder in which can look like shoulder rotation but is again one part acting independently. Lastly the arm should keep a slight bend throughout the entire phase. If the arm becomes completely extended, it will but stress on the back of the arm and bang the bones around the elbow together. If the bend happens too quickly, then the thrower is “cutting it off” at release and would be losing power. This is a delicate matter because it all happens so fast and it can be hard to tell the difference. Our general rule is if the ball goes straight and isn’t dying off at the end they are extending enough.

Arm action is a delicate thing. It is often the first thing that instructors will look to clean up because it seems to be the biggest issue. However, most of the arm action is largely dependent on what the body is doing. Since January of last year, we have made major changes to how we teach throwing. Everyone that throws a baseball in Bardo’s has received an individualized throwing protocol. In our protocol we try to identify the biggest issues limiting, velocity, health, and performance and clean them up with drills. After doing around 1,000 protocols I can say that 90% of the time, it is not the arm action. Arm actions will constantly change, as athletes move faster or slower arm action will change. As athletes grow and develop arm action will change. Many of our athletes have shortened their arm action and a month from now it may be longer. As long as targets are being hit, velocity is improving, it doesn’t hurt, and guys are going back to the dugout long or short doesn’t matter.

Pick a target, move fast, throw hard, and tell us if it hurts, the body will figure out the rest.