An investigation into the use of inertial measurement units to assess the loading profiles of adolescent Badminton players.

Abstract

Monitoring athlete loading is important for understanding athlete adaptations, recovery and injury risk. It is common practice to calculate training load from trunk-mounted accelerometers, housed within Inertial Measurement Units (IMUs), yet many sports have specific anatomical regions where higher loads or injuries occur, which may not be measurable through trunk-mounted IMUs. Badminton was selected for study due to the high prevalence of both lower limb injuries and asymmetries. The aim of this thesis was to provide insights into the use of IMUs for the assessment of training load, measurement of movement asymmetries and in return to training protocols within adolescent Badminton players. This work established the reliability and validity of upper trunk-mounted IMUs for assessing the training load of Badminton-specific movements. While acceptable levels of reliability were found between IMU systems, higher levels of reliability were recorded when the same brand of IMU system was used. However, axis-specific training loads from a single upper trunk-mounted IMU were found to be poorly correlated to both overall and lower limb-specific RPE. These findings suggested that IMU placement nearer or directly on the lower limb (tibia) as the area of investigation may provide greater insights regarding lower limb loading. To understand the potential limitations of IMU placement locations, racket sport coaches were surveyed and found to support the use of IMUs to assess loading in training but not in competition, with a number of IMU placements receiving positive responses, including at the tibia. Training load from tibia-mounted IMUs was then found to differentiate between Badminton players with and without unilateral and bilateral lower limb injury history, which could not be assessed using upper trunk-mounted IMUs. Overall, these findings highlighted the limitations of upper trunk-mounted IMUs for assessing training load in Badminton. By contrast, tibia-mounted IMUs received positive responses from coaches for use during training and provided a novel tool for assessing sport-specific lower limb loading and asymmetries in adolescent Badminton players.