Baseball pitching: signs, symptoms of pitcher fatigue to reduce arm injury

Pitch counts in baseball are so common that during Major League Baseball telecasts, the count number can be found next to the score. Most youth leagues now have pitch count guidelines to help reduce shoulder and elbow overuse injuries. It is often said that these type of throwing-related injuries are reaching epidemic proportions throughout our country. While medical research does not identify optimal pitch counts, pitch count programs have been shown to reduce the risk of shoulder and elbow injury in Little League Baseball by as much as 50 percent (Little League, 2011). However, pitch counts and limits are not the whole story. More important than pitch counts is continuing to throw as the arm and body becomes fatigued.

If a pitcher continues to throw while the arm is tired or fatigued, they are 36 times more likely to develop a shoulder or elbow injury (American Sports Medicine Institute). Arm and body fatigue is by far the greatest risk for shoulder and elbow injuries. Unfortunately, coaches, parents and athletes have not been trained on the warning signs of arm fatigue.

In some cases, the pitch counts can actually increase the risk of overuse injury. For example, an 11-year-old baseball player pitches for the first time of the season. The coach allows the player to make 50 throws (following the league established guidelines) then takes him out of the game. However, not all athletes are the same. This 11-year-old did not perform a pre-season conditioning program. Therefore, his arm has not developed the throwing endurance and tolerance need to make 50 pitches. He also has poor pitching mechanics, causing his body to exert more force on the elbow and shoulder with each throw. Beyond this, he had a shoulder injury last season in which he did not gain full strength of the rotator cuff muscles of the shoulder, thereby leaving him vulnerable for an overuse injury. The coach did the right thing from a pitch count perspective. However, he missed the most important aspect of arm injury prevention: signs and symptoms of pitcher fatigue.

The warning signs and symptoms of pitcher fatigue should trigger a visit to the mound by the coach and potential removal of the pitcher from the game.

1. Looks tired or fatigued: If a pitcher complains of being tired or looks physically fatigued, it is imperative to remove the pitcher from the game and to rest the player at a position which requires few throws at a short distance (i.e., first base).

2. Getting wild: As the body fatigues, there will be compensatory movements and a lack of mechanical efficiency leading to poor ball control and an inability to throw strikes.

3. Decreased throwing velocity: As the body fatigues, the velocity of the fastball will be reduced.

4. Increase time between pitches: When fatigued, the pitcher often increases his time between pitches, walking around the mound or slowing his delivery.

5. Dropped elbow: The arm slot is the motion which the arm follows when throwing. Each player’s arm slot is specific to the athlete, based on genetics and anatomic structure. As the scapular stabilizer muscles (muscles which support the shoulder blade) fatigue, there is poor positioning of the shoulder blade (lack of upward rotation). The “dropped elbow” leads to a higher release point and poor ball control (high pitches).

6. Throwing all arm: As the legs, hips and torso potentially fatigue, the pitcher will compensate with greater arm effort.

7. Reduced stride length: Stride length is measured between the stance foot at the pitching rubber and the stride foot contact point at foot strike. As the pitcher’s stance leg gets tired, there is less ability to push off of the rubber, leading to a lessened stride length.

8. Standing tall: At foot plant in the stride leg thigh, there is a high degree of muscle activation to extend and stabilize the knee in order to accelerate or catapult the hip and pelvis over that stable base. As the pitcher fatigues, it is difficult for that pitcher to maintain the front knee position (flexing and then extending), causing a change in mechanics and decreasing ball velocity.

9. Decreased bend: In a similar process to “standing tall,” the abdominals, hips and back extensors fatigue, causing the pitcher to limit the bending of the torso and trunk.

Many of these signs of pitcher fatigue may be difficult to see with the untrained “naked” eye. It may be necessary to video record (easily done using a smartphone) the player in slow motion to determine these subtle changes in pitch mechanics. The above mentioned signs and symptoms of pitcher fatigue should be used as a guide to identify the pitcher who has reached his limits in throwing in hopes of preventing the arm injuries seen in my physical therapy clinics.