Intra and Inter-rater Reliability of the Volodalen® Scale to Assess Aerial and Terrestrial Running Forms

Running form being a global system defined by several biomechanical parameters, it is of major interest to assess it using a global method. For this purpose, the Volodalen® scale was developed. This scale, based on five items, attributes a global subjective score (V®score) to the running form of individuals and allows their classification along an aerial-terrestrial continuum. As no study has yet reported the reliability of such scale, the aim of this paper was to evaluate its intra- and inter-rater reliability. Thirty-six runners ran two 10-min running trials. Runners were classified according to their V®score by two experts and one novice raters. Relative and absolute reliability, and systematic bias were determined by intra-class correlation coefficient (ICC), coefficient of variation (CV), and statistically significant difference, respectively. Regarding the global V®score, high intra-rater reliability for the expert (CV=6.1 ± 7.0%, ICC=0.940, and p-value=0.864) and high inter-rater reliability for both novice (CV=6.6 ± 6.5%, ICC=0.945, and p-value=0.248) and expert (CV=6.8 ± 5.7%, ICC=0.950, and p-value=0.405) raters were involved. However, several subcomponents of the V®score reported poor inter-rater reliability. The Volodalen® scale is a reliable tool to assess global running forms whatever the degree of expertise whereas the subjective assessment of a single parameter of the V®score is rater-dependent.