(38) A POSITIONAL ASSESSMENT OF FORCE-TIME CHARACTERISTICS ACROSS A COLLEGIATE LACROSSE OFFSEASON TRAINING PROGRAM

Purpose: The purpose of this study was to analyze both the individual progression and positional differences in isometric mid-thigh pull force-time outcomes across a collegiate lacrosse offseason training cycle. Methods: Thirty-five collegiate male lacrosse athletes (86.05±8.93 kg) participated in this study, with three positional alignments used; attack (n = 9), midfield (n = 15), defense/goalie (n=11). Participants participated in three testing sessions over the course of a 14-week offseason training program, consisting of countermovement rebound jumps, and isometric mid-thigh pulls (IMTP), both on Hawkin Dynamics Force Plates. IMTP performance was performed on a ZEUS XZ4050 Prentiss Field Edition isometric rack, set to a neutral grip. Participants completed a five-second isometric pull, at a setting aligned to a 135-degree joint angle for knee flexion. Hawkin Dynamics cloud software was used to analyze peak force (PF) output, time to peak force (TTPF), and RFD across two time points (0-50 ms and 0-100 ms). The order of testing for both IMTP and CMJ rebound were randomized across all three testing sessions. Tested metrics were analyzed using Repeated Measures ANOVA for both whole team averages and positional-specific data, with effect size being calculated utilizing a partial eta squared (η²_p). Statistical Analysis was performed utilizing JASP. Results: Only attack peak force returned a statistically significant result (p = 0.018). However, across both the whole team and positional analysis, all metrics except for attack TTPF and midfield RFD 0-100 improved with medium-to-large effect sizes. Conclusions: While previously stated that only one variable significantly changed, the fact that nearly all variables trended toward improvement with a medium to large effect size indicates that there was an applicable impact of training over the course of the offseason. Instead of limiting the IMTP to a testing metric, an increased incorporation of the IMTP into a weekly training program may further stimulate test-specific adaptations that would elicit significant results. However, isometric strength is correlated with certain dynamic strength measures, so using isometric testing without training is not an unacceptable practice. Practical Applications: This assessment shows that IMTP alone, if not explicitly included as a component of a strength program, may not be the most statistically sensitive means of capturing the compounding adaptations of a dynamic strength training program. However, it must be stated that the requisite time needed to achieve statistical significance may not be sufficiently provided within an offseason training context. Additionally, the variables assessed did return moderate-to-large effect sizes, which adds to the growing consensus amongst both published literature and non-scholarly publications advocating for the usage of these variables in athlete monitoring and assessment. This study also provides an initial foundation for a lacrosse-specific context, with generalizability reaching to other rotational sports such as hockey, baseball, or softball. Acknowledgements: none