Running Asymmetries during a 5-km time trial and their changes over time

Gait asymmetry during running was proven to be inefficient, uneconomical and a possible risk factor for injury. Research has either been conducted in laboratory settings or only discontinuous data were collected. Hence, the present study evaluated gait asymmetries in elite runners by quantifying the differences between ground contact times (GCT) of the right and left foot and their continuous changes over the course of a 5-km time trial. Data of 25 female and male runners of the Swiss orienteering national team were obtained during a 5-km competition on a 400-m outdoor track. By means of the inertial sensor PARTwear, GCT of every step were assessed, divided into GCT of the left and right foot and averaged over 200-m sections. The results revealed an overall asymmetry of 2.6%, significant (p < 0.01) longer GCT during left than right foot contacts and no changes in asymmetry over the course. This is the first study presenting data on asymmetries in elite athletes during a competitive t ime trial. In conclusion, low and consistent GCT asymmetries were observed. The examined athletes had a balanced running style and showed no adverse asymmetry with emerging fatigue, which in turn could affect acute performance and increase injury risk.