Energetic Cost of Runnning Stability Evaluated with Wireless Trunk Accelerometry

The purpose of this study was to determine inter-individual variance in the energetic cost of running (Ec) using dynamic stability measures derived from a single tri-axial trunk accelerometer. These measures were extracted from fifteen male recreational runners at their fastest steady-state treadmill running speed. A select group of dynamic stability measures were entered in a hierarchical regression to explain Ec (kcal.km) after reducing dimensionality with factor analysis. Two dynamic stability parameters could explain an additional 9.9% of inter-individual variance in Ec over and above body mass, attributed to anteroposterior (AP) stride regularity (6.5%) and mediolateral (ML) sample entropy (3.4%). Our results suggest that recreational male runners with better stability in terms of greater AP stride consistency and greater ML trunk movement complexity have an energetic advantage at running speeds approximating race pace.