Predicting Injury in Baseball Pitchers

Baseball pitching is a complex activity that requires a high level of conditioning in the athlete. Baseball pitching is more complex than many other activities that can be definitively categorized as power activities or aerobic activities. Pitching involves all components of physical fitness and does not fit discretely into a category for training. 

Controversy in training has existed for many years. Pitching coaches have differed in their approach to conditioning, with some coaches focusing on aerobic endurance training, while others have focused solely on training for power.  

Research (Beiser, 2012; Brooks 2012) has indicated that aerobic conditioning and overall physical fitness is an important component of training for baseball pitching performance. Research using the Zephyr Bioharness and the lactate pro to measure heart rate, respiratory rate, and blood lactate, indicates that baseball pitchers are working at a high percentage of their VO2 max (not crossing lactate threshold) while still clearing lactate between innings. 

When comparing game conditions with simulated game conditions, research indicates that high heart rates and respiratory rates do not indicate anxiety level during game, as both conditions were reported as having no significant differences in heart rate, respiratory rate, or blood lactate levels (cite research). 

There is a physiological point at which a pitcher is susceptible to injury, and if a pitcher is monitored, and his AT is known, we can predict that point of susceptibility.

Biomechanical analyses of baseball pitching indicate that repetitive submaximal muscular contraction is necessary for success. The lower body produces/generates the force/power needed to pitch the ball, continuously throughout the inning. As the lower body fatigues, body position changes causing different muscle groups to be recruited to maintain the same force or power production. With fatigue onset in the lower body, the upper body muscles that are essential in stabilization of the glenohumeral joint and shoulder girdle, will be recruited to maintain speed pitch (force production), putting the pitcher at increased risk of injury. 

Injury risk in baseball pitchers begins when they cross lactate threshold and begin recruiting muscle fibers in the arm that are essential in stabilization, and that are not usually used during the pitch. Players must recruit additional muscle to sustain throw velocity. 

Baseball pitchers are working at a high percentage of VO2max for an extended period, over the course of the inning. Lactate levels clear, and thus, the player is using predominately aerobic energy over the course of an inning. Crossing AT leads to lactate accumulation post-inning and puts player at risk of injury. As the pitcher’s form breaks down, additional stress is placed on shoulder girdle and glenohumeral joint (Brooks, 2012).

Deconditioned pitchers accumulate more lactate each inning than conditioned pitchers (pilot data, Beiser, 2011). The deconditioned pitchers reach lactate threshold more rapidly, and are at a greater risk of injury due to a breakdown in pitching biomechanics. 

Pitch count is an outdated form of predicting fatigue. It differs for each pitcher, and is not scientific. With all of the technology available today, a shift towards monitoring the physiological and biomechanical indicators of fatigue is essential in predicting injury in pitchers.

Kelly A. Brooks, Ph.D., CSCS*D, HFS, EPC

References


*Brooks, K.A., Carter, J.G., Craven, K.T., Crise, R.L., Beiser, E.J., Szymanski, D.J. (2012). Changes in Baseball Pitching Biomechanics, Pitch Velocity, and Body Position During an Intrasquad Game, Presented at the National Strength and Conditioning Association Annual Meeting, Las Vegas, NV. Published in the Journal of Strength and Conditioning Research 26:S1-S130.

*Beiser, E.J., Szymanski, D.J., Brooks, K.A. (2012). Physiological Response to Baseball Pitching During a Simulated and Intrasquad Game, Presented at the National Strength and Conditioning Association Annual Meeting, Las Vegas, NV. Publication in the Journal of Strength and Conditioning Research 26:S1-S130.