An interdisciplinary investigation into return to play in professional rugby union following lower limb injury

Rugby union is a contact sport with an inherent risk of injury, typically lower limb. The focus of return to play (RTP) following lower limb injury is predominantly at the point of return to sport, with limited assessment of the progression encountered throughout rehabilitation. This thesis used a interdisciplinary approach (using the proposed lower limb functional rehabilitation framework) to examine biomechanical and psychological changes during three phases of RTP (acute, middle, and late), following a lower limb injruy in  professional rugby union players. 

Study 1 investigated injury rates and trends for a professional rugby union team. Players were found to be at the greatest risk of experiencing non-contact lower limb injuries, with knee injuries accounting for the highest incidence and burden across both contact and non-contact mechanisms. In order to undertake a rigorous methodological assessment of the three phases of RTP, study 2 then examined changes within professional rugby union players unilateral static postural control. Study 3A and 3B, assessed the concurrent validity and test-retest reliability of discrete biomechanical assessments of team-based athletes [bilateral and unilateral drop jump; countermovement jump (CMJ) and unilateral lateral hurdle hop]. Static postural control changed over the trial duration, while validity and reliability of discrete biomechanical measures for assessments of RTP phases was supported. 

The methodology validated in study 3A and 3B were subsequently used in studies 4-6 to characterise the RTP of rugby union players following lower limb injury. Study 4 assessed changes in static postural control and self-efficacy during the acute phase of RTP, whilst study 5 assessed alterations to bilateral and unilateral vertical jump and self-efficacy during the middle phase of RTP. Study 6 explored the changes to lateral hurdle hop and self-efficacy during the the late phase of RTP. The results suggest improvements across each phase of RTP between the initial to end testing session. However, inconsistent improvements were evident when comparing pre-injury baseline to the end session. In addition, non-significant medium associations between biomechanical assessment and self-efficacy were observed across all phases. 

The thesis findings suggest that improvements occur in each of the RTP phases for biomechanical and self-efficacy variables, but postural control deficits are present at the end of each phase. The novel findings of the assessment of professional rugby union players’ RTP suggest that practitioners/clinicians need to consider both biomechanical and self-efficacy measurement in their RTP assessment, as although both improve through the rehabilitation process, they are independent of each other. The thesis findings were applied to the proposed lower limb functional rehabilitation framework where the assessment of the independent measurements are accounted for.