Baseball Pitcher Fatigue: Learning to Recognize the Critical Signs!

John R. Mishock, PT, DPT, DC

Most youth baseball leagues now have pitch count guidelines to help reduce shoulder and elbow overuse injuries. Limiting the amount of pitches thrown has reduced shoulder and elbow injuries in Little League Baseball by as much as 50% (Little League, 2011, 2013). However, pitch limits are not the whole story and are often misleading. Each child is different in their physical endurance, training, body make up and pitching mechanics. These differences must be taken into consideration when coaching young pitchers. For example, the pitcher who has poor throwing mechanics and reduced physical endurance is at greater risk for injury with fewer pitches then the athlete who has good pitch mechanics and sufficient endurance of the musculature essential for throwing. So… 25 pitches in an outing could be taxing and put a young athlete at risk even though it is well below most league pitch count guidelines. Because of this ambiguity, pitch counts need to be used in complement with signs of arm and body fatigue.

Recent research has shown that the number one risk factor for throwing related injuries is pitching through arm and body fatigue. A pitcher is an astounding, 36 times more likely to sustain a shoulder or elbow injury when pitching through fatigue (American Sports Medicine Institute, 2014). Unfortunately, most athletes, parents, and coaches have not been trained on the warning signs of arm and body fatigue.

First of all, if a pitcher complains of being tired or looks tired, it is imperative that they stop throwing immediately and rest. Many pitchers will resist being taken out of a game making it important to be able to recognize key pitch mechanic changes that are signs of fatigue.

Pitch mechanic warning signs of arm fatigue:

1. Upright trunk at ball release “standing tall”. As the legs and core (abdominals and hips) musculature begin to tire, there is decreased knee flexion (knee bending) of the landing leg and/or decreased flexion (bending) of the torso or trunk. This pattern causes less external rotation (backward rotation of the throwing arm) and a high release point leading to an elevated fastball.

2. Change in arm slot or angle. As the pitchers shoulder begins to fatigue there is less external rotation of the shoulder causing the elbow to drop changing the arm slot.The change in arm slot puts more strain on the rotator cuff muscles of the shoulder.

3. Relies less on the lower body and more on the arm. The pitcher begins to look like he is throwing “all arm”. This is a sign his legs may be tired.

4. Experiences a drop in pitch velocity. The drop in pitch velocity is a sure sign of fatigue. A consistent 3-5 mph change in average velocity is a good time to make the pitching change.

5. Increase time between pitches. When fatigued the pitcher often increases his time between pitches, walking around the mound or slowing his delivery.
The complete signs of fatigue can be found in Dr. Mishock’s book, “The Rubber Arm: Using science to increase pitch control, improve velocity and prevent elbow and shoulder Injuries.” Can be obtained at Learning to observe these subtle changes in pitch mechanics may help the parent or coach make the critical decision to remove a fatigued pitcher, potentially reducing the incidence of elbow and shoulder injuries.

We can help!

If pain is limiting you from doing the activities you enjoy, give Mishock Physical Therapy a call for a FREE Phone Consultation at (610)327-2600. Email your questions to

Visit our website to read more physical therapy related articles, learn more about our treatment philosophy, our physical therapy staff, and our 6 convenient locations in Gilbertsville, Skippack, Barto, Phoenixville, Limerick, and Pottstown at Our mission is to exceed the expectations of our patients by providing excellence in care and service. We are here to serve you!

New patient scheduling: 610-327-2600