Examination of running pattern consistency across speeds

Area of Science:

• Biomechanics
• Running dynamics
• Human movement analysis

Background:

• Running pattern determinants like duty factor (DF) and step frequency (SF) are crucial for understanding running mechanics.
• Running patterns may vary with speed if changes in DF and SF are inconsistent.
• Assessing running consistency across different speeds and temporal variables is essential.

Purpose of the Study:

• To investigate the consistency of individual running patterns across five speeds (10-18 km/h).
• To examine the consistency of four temporal variables (DF, SF, contact time [tc], flight time [tf]) across speeds.
• To evaluate the consistency of these temporal variables across different running speeds.

Main Methods:

• Acquired 3D whole-body kinematics from 52 runners across a range of speeds.
• Calculated duty factor, step frequency, contact time, and flight time for each runner and speed.
• Normalized deviations from the median for each variable to assess relative positioning.

Main Results:

• Individual running pattern consistency was high to very high for small speed differences (2-4 km/h) and moderate to high for larger differences (6-8 km/h).
• Consistency across temporal variables at a given speed was low between DF and SF, very high between DF and tf, and varied between DF-tc, SF-tc, and SF-tf.
• Running pattern consistency decreased as speed differences increased.

Conclusions:

• Running patterns should be assessed across a range of speeds to capture variability.
• Low consistency between DF and SF at a given speed highlights the importance of using both to fully describe running patterns.
• Individual running mechanics exhibit speed-dependent and variable-dependent consistency.