Introduction: Athletic groin pain (AGP) is a common injury in sports involving repetitive twisting, kicking and turning (Werner et al., 2009; Thorborg et al., 2017). In male soccer for example, AGP incidence accounts for 4 -19% of all injuries (Walden, Hagglund and Ekstrand, 2015). Despite this, there remains a dearth of literature investigating the three-dimensional biomechanics of AGP. The primary aim of this PhD thesis is to evaluate the biomechanical factors affected by AGP to enhance our understanding of this injury. Methods: This thesis incorporates the work from eight investigations including one published systematic review incorporated in the review of literature, two methodological studies and five experimental investigations. As a body of work, this is the one of the largest investigations of AGP biomechanics conducted to date as it includes an investigation of over 200 AGP patients and 85 uninjured subjects. Results and Conclusion: Multiple biomechanical factors were identified that may be related to AGP. The mechanics of the trunk and hip are commonly affected by this injury, particularly in the frontal plane, and may represent targets for rehabilitation. The ankle joint was also consistently and strongly identified as being affected by AGP but generally failed to change significantly from pre- to post- rehabilitation. As such, future research is warranted to ascertain if AGP rehabilitation could be further enhanced with a focus on improving ankle function. Given that variability and complexity appear to be affected by AGP with large effect sizes, it is suggested that the rehabilitation of AGP should follow a dynamic systems theory approach (Newell 1986). The results from this PhD thesis have made novel contributions on an empirical, theoretical, methodological and practical level and the findings can help guide clinical practice and the design of future prospective research.