Stud Type Affects Knee Biomechanics on Infilled Synthetic Turf during a 180° Cut, but not during a Single-Leg Land-Cut Task 1 Biomechanics/Sports Medicine Lab, The University of Tennessee, Knoxville, TN, USA 2 Department of Plant Sciences, The University of Tennessee, Knoxville, TN, USA As expected, the land-cut movement involved increased knee power absorption, power generation, and extensor moment compared to the 180° cut. However, shoe effects lie only in the 180° cut. The decreased medial ground reaction force 2, knee adduction moments, and extensor moments in NTS suggest the knee may be in a safer environment using this studded shoe during cutting maneuvers. Reduced knee adduction moments in NTS could have implications in non- contact ACL injury. References 1 Ramirez, M., Schaffer, K. B., Shen, H., Kashani, S., & Kraus, J. F. (2006). Injuries to High School Football Athletes in California. Am J Sports Med, 34(7), Zhang, S. Brock, E., Milner, C.E., Brosnan, J.T. and Sorochan, J.C. (2013). Effects of Two Football Studs on Ground Reaction Force of Single-Leg Landing and Cutting Movements on Infilled Synthetic Turf Annual Meeting of American Society of Biomechanics, Omaha, Nebraska. Biomechanics/Sports Medicine Laboratory, The University of Tennessee Conclusions Introduction Higher football related ACL injury frequencies have been reported on synthetic turfs compared to natural turfs. 1 Limited research has investigated the effects of stud type (either synthetic or natural) of cleats worn on knee joint biomechanics. The purpose of this study was to examine the knee biomechanics of a non-studded running shoe (RS), a football shoe with natural turf studs (NTS), and with synthetic turf studs (STS) during 90° single-leg land-cut and 180° cut tasks on 3 rd generation synthetic turf. Participants: Fourteen recreational football players participated in this study Each had a minimum of 3 years of football experience, exercised at least 3 days per week, and played football at least once per week Instrumentation: A 9-camera motion analysis system (120 Hz, Vicon Motion Analysis Inc., Oxford, UK): three-dimensional (3D) kinematics during data collection. One force platform (1200 Hz, American Mechanical Technology Inc., Watertown, MA, USA) and a 3 way runway were covered with a 51 mm monofilament synthetic turf (Astroturf Gameday 3D, AstroTurf, Dalton, GA ) Visual3D Biomechanical Analysis Suite: 3D kinematic and kinetics. Moments were calculated as internal moments. Testing Protocol: Five minute self-directed warm-up on a treadmill Two tasks, a run and 180° cut and a single-leg 90° land-cut, were performed wearing each shoe: RS, NTS, and STS for a total of five successful trials Statistical Analyses A 2 x 3 (task x shoe) Repeated Measures Analysis of Variance was used, followed by post-hoc paired samples t-tests (P<0.05) Methodology Results 90° Single-Leg Land-Cut and 180° cut Tasks Hunter Bennett 1, Songning Zhang 1, Elizabeth Brock 1, James T. Brosnan 2, John C. Sorochan 2 Table 1. GRFs and knee biomechanics variables: mean±STD.