PURPOSE: Altered biomechanical characteristics of jumping and change of direction tasks are suggested to persist following ACL injury of the knee, which may increase risk of subsequent injury. Athletes within the AFL-W are reported to sustain ACL injury at a rate 4-8x greater than their male counterparts, representing a significant welfare issue. The athlete in question was rehabilitating her 3rd ACL rupture. 

METHODS: 3-Dimensional kinematic values were obtained for foot/ankle, knee, and hip joints at time of ground contact as well as peak knee flexion during a number functional strength, jumping and change of direction tasks, using a marker-based camera System (Vicon, Oxford UK). Results were compared to a ‘normal’ range (defined as within +/- 2 standard deviations of the mean of a database of the results of 1200 male and female Pitch Ready testing participants. 

RESULTS: On initial assessment the athlete demonstrated low knee flexion on the operated leg, and increased knee varus and relative increased external rotation of both legs when compared to ‘normal’ data. The athlete also demonstrated increased heel strike at time of foot contact, bilaterally. Feedback regarding testing results was given to club staff, in addition to recommended rehabilitation interventions to address the identified kinematic deficits. 

Low knee flexion (in the absence of capacity deficits) was addressed by concentric force production drills from a starting point of knee flexion, initially with body weight support. As the athlete’s skill and capacity progressed, the athlete moved to concentric-eccentric versions, then to horizontal force production (e.g. partner Borsov hops). Foot/ankle kinematics were addressed by drills focusing on ankle stiffness while maintaining foot neutral in the axial plane. As athlete skill and capacity improved, resistance was added to challenge the athlete’s control off-axis and from multiple directions. 

On re-assessment following 4 weeks of intervention, the athlete demonstrated knee flexion and heel strike within ‘normal’ range. Her relative external rotation was within normal range on her operated side post intervention, but remained outside of normal range on her opposite leg. The athlete subsequently returned to play, with recommendations to focus similar interventions on the uninjured side. 

CONCLUSION: This case study highlights some key focus points in determining readiness to return to sport, as well as serving as a practical example of how data can be utilised in the rehabilitation process. Based on the information observed in this case study, kinematic features of jumping and change of direction associated with increased risk of ACL may be also to be changed in as little as 4 weeks with tailored interventions. Test-retest and evidence of change in the post-operative period can be a useful addition to return-to-training and return-to-play decision making.