ABSTRACT
INTRODUCTION: Delayed onset muscle soreness (DOMS) and Anterior Cruciate Ligament (ACL) injuries are both prevalent in sport. It is currently unknown whether DOMS increases ACL injury risk. AIM: This study aimed to provide preliminary insight on whether DOMS affects ACL injury risk by investigating whether DOMS affects the biomechanical variables of the DVJ that have been identified as risk factors for future ACL injury. METHODS: This was a randomised control trial involving 32 active individuals aged 18-35 years, with no history of ACL injury. Participants underwent two sessions of force-plate testing and 3D motion analysis of the drop vertical jump (DVJ). The DVJ was chosen as it has been investigated prospectively for association with future ACL injury. Initial testing was followed by randomisation to DOMS or control group. The DOMS group underwent a DOMS-inducing exercise protocol, the control group did not. Both groups were re-tested 48 h after initial testing. Five variables of the DVJ that have been associated with future ACL injury were chosen for analysis - peak knee flexion angle, peak vertical ground reaction force, ground contact time, peak knee abduction angle & peak knee abduction moment. Between-group differences were compared using a two-way mixed analysis of variance; alpha level set to 0.05. RESULTS: DOMS was successfully induced in all participants of the DOMS group however no statistically significant group x time interactions were found for any of the five variables analysed. CONCLUSIONS: DOMS did not affect the biomechanical variables of the DVJ that have been associated with future ACL injury. By extension, this may suggest that DOMS might not affect ACL injury risk. However, it is also possible that certain attributes of the DVJ meant that any effect of DOMS was simply unable to be quantified, even if an effect existed. All considered, our position is that conclusion cannot be drawn from this study alone on whether DOMS affects ACL injury risk. Further research is required.
