Biomechanical indices represented on radar chart for assessment of performance and infringements in elite race-walkers

Nowadays, technology in sport plays an important role to help training and judgement processes. This study proposes the use of a wearable inertial system to derive novel biomechanical indices for the assessment of performance and infringements in race-walking. These indices are built from five inertial-based parameters: loss of ground contact time, loss of ground contact step classification, step length ratio, step cadence and smoothness. The biomechanical indices are customized for elite race-walkers, and represented on a radar chart for an intuitive analysis of performance and infringements. From the radar chart, a synthetic index regarding the athlete's overall gesture is derived. The validation of the biomechanical indices is carried out in field tests, involving nine elite race-walkers wearing an inertial sensor located at the end of the column vertebra (L5-S1). A statistical analysis is used to determinate the quality and reliability of the proposed indices and of their representation. The results show that these biomechanical indices can be implemented on a wearable inertial system for assistance in training and judgement in race-walking.