The aim of this study was to test Sixty-one male athletes (age: 20.7 ± 3.8 years, height: 1.77 ± 0.06 m, mass: 74.7 ± 10.0 kg) from multiple sports (soccer, rugby, and cricket) in 6 trials of the modified and traditional 505 on their right leg, whereby 3D motion and ground reaction force data were collected during the COD. Pearson’s and Spearman’s correlations were used to explore the relationships between biomechanical variables and COD completion time. Independent t-tests and Hedges’ g effect sizes were conducted between faster (top 20) and slower (bottom 20) performers to explore differences in biomechanical variables. Key kinetic and kinematic differences were demonstrated between faster and slower performers with statistically significant (p ≤ 0.05) and meaningful differences (g = 0.56-2.70) observed. Faster COD performers displayed greater peak and mean horizontal propulsive forces (PF) in shorter ground contact times, more horizontally orientated peak resultant braking and PFs, greater horizontal to vertical mean and peak braking and PF ratios, greater approach velocities, and displayed greater reductions in velocity over key instances of the COD. In addition, faster performers displayed greater penultimate foot contact (PFC) hip, knee, and ankle dorsi-flexion angles, greater medial trunk lean, and greater internal pelvic and foot rotation. These aforementioned variables were also moderately to very largely (r or ρ = 0.317-0.795, p ≤ 0.013) associated with faster COD performance. Consequently, practitioners should focus not only on developing their athletes’ ability to express force rapidly, but also develop their technical ability to apply force horizontally. In addition, practitioners should consider coaching a 180° turning strategy that emphasizes high PFC triple flexion for center of mass lowering while also encouraging whole-body rotation to effectively align the body toward the exit for faster performance.
Coaching Implications: In addition to proper COD mechanics, the amount of horizontal force applied to the ground and the speed with which force is applied determine how fast an athlete accelerates to maximum speed after and fake-and-cut maneuver. COD training to increase ground reaction force and reduce ground contact time requires specific diagonal plyometric, weight training,, and sprint loading exercises that closely mimic the change of direction movement and meet and/or exceed the current force an athlete can apply.
Source: Dos’Santos, T, McBurnie, A, Thomas, C, Comfort, P, and Jones, PA. 2020. Biomechanical determinants of the modified and traditional 505 change of direction speed test. J Strength Cond Res 34(5): 1285-1296.
