Categorizing running styles via the duty factor | Biomechanics |Science Update

running analysis
17 Feb 2023

Soccer players run at variant speeds throughout a game. A recent study by Brian Hanley et al. from the Carnegie School of Sport at Leeds Beckett University utilized a gaitway 3d instrumented treadmill to asses the duty factor, a dimensionless ratio based on temporal variables.

The duty factor, as the ratio of contact duration to stride duration, turns out to be an effective measure to categorize running styles amongst the soccer players.

Players with a low duty factor are characterized by an aerial running style, with shorter contact time and longer flight times, just like metaphorical gazelles. The opposite category – grizzlies - will typically not make such leaps, but show a higher step frequency.

Duty factor, peak vertical forces, step lengths and step frequencies, contact times, vertical displacements are only few parameters that could be derived simultaneously from the gaitway 3d and its software for this study. The simultaneous measurement of 3d forces, pressures and torques allows deep and comprehensive insights to movement pattern.


Hanley, B., Tucker, C. B., Gallagher, L., Parelkar, P., Thomas, L., Crespo, R., & Price, R. J. (2022). Grizzlies and gazelles: Duty factor is an effective measure for categorizing running style in English Premier League soccer players. Frontiers in Sports and Active Living, 4, 939676.