Mechanical Alterations during 800-m Self-Paced Track Running

Area of Science:

• Sports Science
• Biomechanics
• Human Movement Analysis

Background:

• Understanding the mechanical demands of middle-distance running is crucial for performance optimization.
• Previous research has primarily focused on elite athletes, leaving a gap in knowledge regarding non-specialist runners.
• The time course of kinematic and kinetic changes during a self-paced 800-meter run requires further investigation.

Purpose of the Study:

• To analyze the changes in running mechanics and kinetics throughout an 800-meter run in physical education students.
• To investigate the alterations in ground reaction forces, stride characteristics, and spring-mass model parameters over the course of the race.
• To compare the running performance and biomechanical adaptations between the early and later stages of the 800-meter distance.

Main Methods:

• Eighteen physical education students completed a self-paced 800-meter run on a 200-meter indoor track.
• Ground reaction forces were measured using a force platform system integrated into the track.
• Running kinetics, kinematics, and spring-mass characteristics were calculated at each 100-meter interval.

Main Results:

• Running velocity progressively decreased from 100m to 700m, with a significant drop in the second half of the race.
• Stride length and peak braking/push-off forces decreased significantly, while stride frequency showed a non-significant trend.
• Center of mass vertical displacement increased, indicating altered running economy, and vertical stiffness decreased, while leg stiffness remained unchanged.

Conclusions:

• Non-specialist runners experience a decline in running velocity and stride length during an 800-meter run, primarily in the latter stages.
• Reduced peak braking and push-off forces contribute to shorter stride length, suggesting altered force application strategies.
• The observed changes in vertical stiffness, without changes in leg stiffness, indicate a shift in the body's damping and elastic properties during sustained running efforts.