kinematic analysis of hurdling performances at 2000 united states ...

coincide with the hurdle clearance position rather than in front. If this alignment of the trajectory peak
was made then the hurdlers would not need to produce as great an elevation and shorter flight times
would result. Only, one of the high hurdlers’ CM peak trajectories coincided with the hurdle clearance.
The hurdlers’ average take-off distance was 224.6 cm and their landing distance was 143.8 cm. These
displacements were very close to the 213 cm (7 ft) take-off and 122 cm (4 ft) landing displacements, that
are typically discussed by hurdle coach clinicians. The alterations in the horizontal velocities of the CM
during the take-off found that the high hurdlers increased their velocity by 13 cmhsec - 1 or
approximately 1% of their running velocity. These accelerative changes in the horizontal velocities for
the hurdlers would be indicative of an appropriate stride length foot at foot plant prior to take-off.
During the landing phase, the hurdlers experienced an acceleration of 84 cmhsec -1 or about 7.6% of
their running velocity, as they came over of the hurdle, which would be indicative of the hurdler landing
in a tall running position rather than settling and retarding their running velocity. The application of
greater horizontal forces would be indicated by shorter ground contact times and those horizontal forces
may only be generated when the hurdler is contact on the ground, therefore long flight times while
clearing the hurdle would not be beneficial in achieving fast hurdling times. The small vertical CM
displacements observed for the hurdlers during hurdle clearance indicated that the hurdlers strode over
the hurdle, thus reducing the flight time and increasing the acceleration of the body when in contact with
the ground.
CONCLUSIONS: The hurdlers experienced their greatest acceleration during the landing phase after
the hurdle clearance than the step prior to take-off. Only one of the four hurdlers’ apex of their CM
flight trajectory occurred over the hurdle. The hurdlers’ apex of their CM parabolic pathway should
occur while clearing the hurdle. A horizontal displacement between the CM apex and the hurdle would
be indicative of improper striding or flight trajectories, where the take-off step occurred too close or too
far from the hurdle or they projected their body at an improper angle. An apex displacement would
indicate that the hurdler reached his peak flight position either slightly before or after the hurdle. The
simultaneous integration of video, stick figures and data was used as a visual coaching and research tool
for performing a hurdle analysis and providing immediate feedback to the athlete and coach.
REFERENCES:
Finch, A., Ariel, G., & McNichols, J. (2000). Integrated kinematic data analysis of American elite
hurdlers. In: Proceedings of International Symposium on Biomechanics in Sports XVIII, The University
of Hong Kong, Hong Kong, China.
Mann, R. (1993). The mechanics of sprinting and hurdling. Elite Hurdler Project technical report.
United States Track & Field Association, 1-135.
McDonald, C., & Dapena, J. (1991). Linear kinematics of the men’s 110-m and women’s 100-m
hurdles races. Medicine & Science in Sports & Exercise, 23:1382-91.