BIOMECHANICAL DIFFERENCES OF TWO COMMON FOOTBALL MOVEMENT TASKS IN STUDDED AND NON-STUDDED SHOE CONDITIONS ON INFILLED SYNTHETIC TURF

The purpose of this study was to examine kinematic and kinetic differences in three shoe conditions (traditional football shoes with natural and synthetic turf studs and a neutral running shoe) during two common football movements (a 180° cut and a land-cut movement) on infilled synthetic turf. Fourteen recreational male football players performed five trials in all three shoe conditions for a 180° cut as well as a land-cut maneuver. The kinematic and kinetic variables were analyzed with a 3 x 2 (shoe x movement) repeated measures analysis of variance (ANOVA, p<0.05). Peak free moment was significantly greater for the land-cut trials (p<0.001). Vertical GRFs were significantly greater for the land-cut trials (p<0.001). A cleat x movement interaction was seen for time to vertical impact GRF (p=0.048). A cleat main effect was found for time to vertical impact between natural turf cleat and synthetic turf cleat (p=0.019). Vertical loading rate was significantly greater in land-cut trials. Peak medial GRFs showed a significant cleat x movement interaction (p=0.002). The results from this study suggest that land-cut movement elicit greater vertical GRF and vertical impact loadings rates. The running shoe had significantly less dorsiflexion range of motion (ROM) than the synthetic turf studs. A significant cleat main effect was found for peak eversion velocity (p=0.005). Post hoc comparisons showed that it was significantly smaller in shoe than that natural turf stud (p=0.016) and synthetic turf stud (p=0.002). In general, there was a lack of differences between the shoe conditions for GRFs and kinematic variables. For the 180° cut movement, natural turf studs produced lowest peak medial GRF compared to the synthetic turf studs and the shoe. The results from this study suggest that land-cut movement elicit greater vertical GRF and vertical impact loadings rates. In general, there was a lack of differences of GRFs and kinematic variables between the shoe conditions. For the 180° cut movement, natural turf studs produced lowest peak medial GRF compared to the synthetic turf studs and the shoe. Overall, increased GRFs, especially in combination with rapid change of direction and deceleration may increase the chance of injury.