In Major League Baseball, lower extremity biomechanics can predict performance, according to a new study.
Lower Extremity Biomechanics Predictive of Pitching Success
The researchers of “Lower Extremity Biomechanics Predicts Major League Baseball Player Performance” sought to better understand the relationship between lower extremity biomechanics and advanced statistical metrics.
To do this, they established normative biomechanical parameters for countermovement jumps in Major League Baseball and analyzed the relationship between countermovement jump-developed algorithms and advanced statistical metrics.
Players in two Major League Baseball organizations were included in the study that was published on July 8, 2021, in the Orthopaedic Journal of Sports Medicine.
The researchers collected ground-reaction force data, including the eccentric rate of force development, concentric vertical force and concentric vertical impulse as well as Sparta Score at the beginning of each baseball seasons from 2013 to 2017.
They also measured advanced statistical metrics such as fielding independent pitching, weighted stolen base runs and weighted on-base average during the season. The minimal detectable change was calculated for each countermovement jump variable.
Overall, a total of 151 pitchers and 138 batters were included in the analysis. The minimal detectable change for eccentric rate of force development, concentric vertical force and concentric vertical impulse and Sparta Score was 10.3, 8.1, 8.7 and 4.6, respectively.
The researchers also found a weak, but still statistically significant correlation between the Sparta Score and weighted stolen base runs (r = 0.23; p = .007) but not with any of the other advanced metrics.
The analysis also showed that older pitchers had better fielding independent pitching and higher Sparta Scores than younger pitchers.
The researchers wrote, “There was a positive but weak correlation between the Sparta Score and base-stealing performance among professional baseball players. Additionally, older pitchers with a higher Sparta Score had statistically superior fielding independent pitching compared with younger pitchers with a similar Sparta Score after adjusting for age.”

Discussion
This is a fascinating development. In my practice we've seen similar outcomes with the revised protocol. The key differentiator seems to be patient selection criteria. Has anyone else noticed the correlation with BMI thresholds?
Great point. I'd push back slightly on the conclusion, the sample size in the cited study is too small to draw population-level inferences. That said, the directional signal is compelling and worth a larger RCT.
We implemented a similar approach last year. Early results are promising but we're still gathering 12-month follow-up data. Happy to share our protocol if anyone is interested.
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