Potential Sport Crossover Benefit of Golf Swing Motion to Lacrosse Shot Motion Vincent HK, Wasser JG, Zdziarski LA, Chen C, Leavitt T, McClelland JM, Herman DC, Zaremski JL, Vincent KR. University of Florida, Dept of Orthopaedics and Rehabilitation, Gainesville, FL Background Results Methods (cont). A golf swing has similar motion components to a lacrosse shot, including: The use of a long lever arm (club vs crosse) Rotation of the torso over the pelvis (backswing vs crank-back) Coordination of sequential peak angular velocities that impart a high ball speed. Lacrosse players may obtain skill crossover from golf that enhances shooting form and ball speed, but this is not yet known. PURPOSE: The purpose of this study was to compare the shot kinematics and speed of male lacrosse players who golf compared to non-golfers. The golfers demonstrated 19% faster ball speed and 17% shorter shot duration during the lacrosse shot than non-golfers (p<0.05). Kinematics that were different in the golfers included the X-factor at crank back, indicating better potential energy storage than non-golfers. The golfers developed their maximal pelvis and upper torso angular velocities earlier in the shot cycle compared to non-golfers. (both p<0.05). These findings infer a possible crossover effect of the golf swing to lacrosse shooting. In Figure 2, golfers are taught to initiate pelvis horizontal rotation early (2a) and then accelerate the shoulder and club into follow-through (2b-2c)- all of which can be used to improve lacrosse shot speed. Figures 1a-c. Lacrosse shot crank back and initial foot contact, 0% of shot (a), ball release, 100% of shot (b) and follow-through (c). 1a. 1b. 1c. Figures 2a-c. Golf swing start of downswing, 0% (a), ball contact 100% of swing (b) and follow-through (c). 2a. 2b. 2c. Methods Table 1. Lacrosse shot kinematics in players who do and do not golf. Values are means ± standard deviation (SD). *sig at p<0.05 Golfers Non-golfers p (sig) Ball speed (km/hr) 132 ± 15 105 ± 14 0.002 * Shot time (s) 0.57 ± 0.09 0.70 ± 0.24 0.243 X-factor () -37.3 ± 8.1 -29.2 ± 5.2 0.024 * Maximal angular velocity ( /s) Pelvis 551 ± 124 517 ± 119 0.582 Upper torso 697 ± 156 625 ± 121 0.307 Shoulder 943 ± 175 818 ± 153 0.140 Crosse 1727 ± 542 1578 ± 360 0.505 Timing of maximal velocities in shot cycle (% of shot) Pelvis 34.6 ± 18.1 57.1 ± 18.3 0.024 * Upper torso 57.2 ± 9.0 70.6 ± 15.1 0.050 * Shoulder 70.1 ± 12.4 80.7 ± 15.5 0.156 Design: This was a cross-sectional study of healthy, male lacrosse players (19.5±3.6 yr, 79.3±12.4kg, 180±8 cm) who either did (n=7) and did not regularly golf (n=9). Non-golfers were age and position matched to golfers. Methods: Motion was captured using a high-speed, 12-camera optical 3D motion capture system (Motion Analysis Corp.). A set of 28 reflective markers was developed for the shooting motion.1 Shot time was defined from lead foot plant (0% of shot) to ball release (100% of shot).1 Peak angular velocities of the pelvis, torso, shoulder, stick, and relative times at which these events occurred were found. Shoulder motion excursion at crank-back was determined relative to the pelvis position termed X-factor.2 Kinematics of the overhead lacrosse shot using the dominant arm were calculated using standard rigid body mechanics equations. Kinematic events were expressed as a percent of the shot cycle. After warm up, each player performed 10 overhead shots with the dominant and non-dominant arms, and the three fastest trials were averaged. Data were processed using Matlab© software, and parametric statistics were used to determine if differences between golfers and non-golfers existed. Conclusions Several key features of the golf swing may translate to improved lacrosse shot motion and ball speed. Lacrosse players may consider golf as a secondary sport to help transfer rotational skills to shooting, by enhancing early peak segmental angular velocities and ball speed. Citations 1. Vincent HK et al. Shooting motion in high school, collegiate, and professional men's lacrosse players. Sports Biomech. 2015;14(4):448-58. 2. Brown SJ et al. The X-Factor: an evaluation of common methods used to analyse major inter-segment kinematics during the golf swing. J Sports Sci. 2013;31(11):1156-63.