A Return to Play Case Study, Observing an Elite Youth Football Player During the Sport Specific Field Phase of Rehabilitation Following ACL Reconstruction, Using Foot- Mounted Inertial Measurement Units to Quantify Gait Mechanics and Technical Actions.

Background: Anterior cruciate ligament (ACL) injuries require long recovery periods and can severely impact a player's career. Effective rehabilitation protocols and monitoring devices are crucial for players to return to pre-injury performance levels. This master's thesis uses the PlayerMaker system and its foot-mounted inertial measurement units (IMU) to investigate the recovery process of an elite youth football player following ACL reconstruction, capturing detailed physical, biomechanical and technical data during sport-specific on-field phases.
Methods: A longitudinal observational methodology documented the return to play (RTP) process, using the PlayerMaker system to collect comprehensive data on physical performance, technical abilities and gait mechanics at different stages of rehabilitation. Performance measures were compared with two healthy reference players using statistical analysis.
Results: Over 55 supervised training sessions, the case player showed higher physical and technical performance in rehabilitation than in team training. Gait mechanics also improved significantly. Compared to reference players, there were no significant differences in team training performance measures (p > .05), although the case player occasionally outperformed his peers (p < .05). Significant improvements in explosive power and speed were documented post-injury.
Conclusions: The thesis confirms the effectiveness of using the PlayerMaker system within an RTP protocol to facilitate successful ACL rehabilitation. It highlights substantial improvements in physical and technical performance, resulting in the player not only matching, but exceeding the performance of healthy peers, thus ensuring a robust return to competitive play. This approach demonstrates how modern monitoring technology can profoundly benefit the rehabilitation of athletes in sports medicine.