Kinetic and kinematic comparisons in high school pitchers with low and high pitch location consistency.

Abstract

Although ball velocity has often been associated with increased kinetics at the upper extremity and risk of injury in youth and adolescent pitchers, it is unclear if the performance metric pitch location consistency has any positive or negative associations with pitching kinetics. High school pitchers (n=59) pitched 8-12 fastballs using 3D motion capture (480 Hz). Pitchers were divided into high-consistency (HiCon) and low-consistency (LoCon) groups based on the absolute center deviation of each pitcher's pitch to the center of the pitcher's mean pitch location. Ninety-five percent confidence ellipses with major and minor radii were constructed, and kinematics and kinetics were compared between groups. Compared with LoCon pitchers, HiCon pitchers had decreased lead hip flexion at elbow extension (40°±12° vs. 52°±13°, respectively, P=.008), and at foot contact, decreased back hip extension (-1° ±10° vs. -10° ±13°, respectively, P=.038) and increased back hip internal rotation (9°±15° vs. -2° ± 15°, respectively, P=.043). LoCon pitchers achieved maximum lead hip flexion earlier in the pitch (61.3%±23.2% vs. 75.8%±15.1%, respectively, P=.039). A multiregression model predicted 0.49 of variance in pitch location consistency using kinematic inputs. Pitchers who differ in pitch location consistency outcomes do not appear to demonstrate physiologically unsafe kinematics. High school pitchers who strive for improved pitch consistency can consider adjusting parameters of hip kinematics during early portions of the pitch.