2015 ISAKOS Biennial Congress ePoster #2602

Predictors of Throwing Velocity in Youth and Adolescent Pitchers

Peter Chalmers, MD, Chicago, IL UNITED STATES
Terrence Sgroi, DPT, Chicago UNITED STATES
Andrew Riff, MD, Chicago, IL UNITED STATES
Matthew Lesniak, DPT, Chicago UNITED STATES
Eli Sayegh, BA, New York, NY UNITED STATES
Markus Wimmer, MD, Chicago, IL UNITED STATES
Nikhil N. Verma, MD, Chicago, IL UNITED STATES
Brian J. Cole, MD, MBA, Chicago, IL UNITED STATES
Anthony A. Romeo, MD, Burr Ridge, IL UNITED STATES
Rush University Medical Center, Chicago, IL, USA

FDA Status Cleared

Summary: Pitch velocity is most strongly correlated with age, height, separation of the hips and shoulders, and stride length.

Abstract:

Introduction

Shoulder and elbow injuries are a common cause of pain, dysfunction, and inability to play in overhead throwers. Pitch velocity plays an integral part in the etiology of these injuries; however, the demographic and biomechanical correlates with throwing velocity remain poorly understood. We hypothesized that pitchers with higher velocity would have shared demographic and kinematic characteristics.

Methods

Normal pre-season youth and adolescent pitchers underwent dual-orthogonal high-speed video analysis while pitch velocity was collected with a radar gun. Demographic and pitching history data was also collected. Kinematic data and observational mechanics were recorded. Multivariate regression analysis was performed.

Results

Four hundred and twenty pitchers were included, who pitched with a mean velocity of 64±10 miles per hour (mph). After multivariate logistic regression analysis the most important correlates with pitch velocity were age (p<0.001, R2=0.658), height (p<0.001, R2=0.076), separation of the hips and shoulders (p<0.001, R2=0.027), and stride length (p<0.001, R2=0.016) – in combination these four variables explained 78% of the variance in pitch velocity. Each year of age was associated with a mean±standard deviation 1.5±0.1 mph increase in velocity, each inch in height was associated with a 1.2±0.2 mph increase, separation of the hips and shoulders was associated with an 2.6±0.5 mph increase, and an increase in stride length by 10% of subject height was associated with a 1.9±0.4 mph increase.

Conclusion

Pitch velocity is most strongly correlated with age, height, separation of the hips and shoulders, and stride length.