3-D biomechanical analysis of sprint hurdles at different competitive levels.

Four different competition sessions were examined using three-dimensional video techniques to study the hurdle clearance at different levels of performance in male and female athletes. In total, 28 trials were digitized (50 Hz) using the "Kine Analysis" software package. The Direct Linear Transformation algorithm and cross-validated quintic spline were carried out for the data. This study showed that the better female group performed with a greater take-off distance (P = 0.0006), making a lower take-off angle possible. This results in a greater horizontal velocity (P = 0.0002) than the lower level female group. Relative to the horizontal displacement of the CM from take-off to landing, the CM parabola peak occurred at 54 +/- 4% and 55 +/- 6% from take-off for the two male groups and 54 +/- 7% and 51 +/- 3% for the two female groups. There were no statistically significant differences between either the male groups or the female groups or the sexes. This would indicate that the relative peaks are at a similar point in the different parabolic paths. However, in absolute terms the peak occurred at different positions in the different groups. The reason for this is unclear and will need further investigation.