(48) COUNTERMOVEMENT JUMP POSITIONAL ANALYSIS IN COLLEGIATE BASEBALL PLAYERS

Purpose: The countermovement jump (CMJ) has previously been implemented as a tool for assessing lower body neuromuscular characteristics in collegiate and professional baseball players. CMJ metrics have been significantly associated with hitting and pitching performance outcomes providing evidence for its ecological validity. The purpose of the current investigation was to conduct a position-specific analysis of CMJ profiles in a cohort of collegiate baseball players. Methods: Forty-five (age: 20.9 ± 1.3 yrs; height: 184 ± 5.8 cm; body mass: 88.7 ± 8.3 kg) Division 1 collegiate baseball players participated in the current investigation. All athletes completed a standard warm-up before performing two maximal effort CMJs (i.e., hands on hips) with a rest interval of 15-seconds. All testing was performed using a dual uniaxial force plate system (ForceDecks Max, VALD Performance, Brisbane, Queensland Australia) sampling at 1,000 Hz. CMJ metrics were chosen based on previous investigations and to gain additional insight into neuromuscular characteristics of each position with data averaged across the two jumps. CMJ metrics analyzed included: braking phase duration and impulse, countermovement depth, reactive strength index – modified, eccentric and concentric duration, peak velocity, mean force, peak force, mean power, and peak power. A one-way analysis of variance (ANOVA) was used to detect statistically significant differences (p < 0.05) in CMJ metrics between positions, with participants classified as Catchers (CATs), Infielders (IFs), Outfielders (OFs), and Pitchers (PITs). Results: No statistically significant differences in anthropometric metrics between positions were reported. However, statistically significant differences were detected for CMJ eccentric peak velocity (f=3.570, p=0.022, η²=0.215), eccentric mean power (f =3.845, p =0.017, η²= 0.228), and eccentric peak power (f=3.838, p=0.17, η²=0.228) (Table 1). Post-hoc analysis indicated statistically significant differences were present between PITs and IFs for both eccentric mean power (p=0.048) and eccentric peak velocity (p=0.040), though no differences were detected between groups for eccentric peak power. Conclusions: The current analysis indicates that non-pitching positions display similar neuromuscular characteristics. The differences observed in eccentric CMJ metrics for PITs may be due to the greater eccentric loading that is experienced by the lower limbs during the different phases of a pitch. This may potentially influence strategies of power production due to unique throwing mechanics of pitching. Future longitudinal studies should be conducted to assess changes in these metrics. Practical Applications: CMJ metrics solely may not be able to differentiate between non-pitching positions. However, the current analysis may provide insight into the different CMJ characteristics for power production that maybe unique to PITs and influence pitching outcomes. Acknowledgements: None