Background: Both Anterior Cruciate Ligament injury and Foot Pronation are factors that alter lower extremity biomechanics. However, the combined effect of these two conditions on landing forces is not well understood.

Methods: In this cross-sectional study, 15 men with Anterior Cruciate Ligament Reconstruction and foot pronation and 15 matched healthy men participated. Participants performed a single-leg landing task from a 30 cm height onto a force plate. Peak ground reaction forces and free moment were compared using an independent t-test (P<0.05).

Findings: The group with Anterior Cruciate Ligament Reconstruction and foot pronation showed a significantly greater first peak vertical ground reaction force (19.08% increase; P=0.048) compared to the healthy group. Additionally, negative free moment (P=0.007) and positive free moment (40.95% decrease; P=0.017) were significantly lower in this group. No significant differences were observed in other components (P > 0.05).

Conclusion: The combination of Anterior Cruciate Ligament Reconstruction and foot pronation results in a different landing strategy, characterized by greater vertical impact force and lower rotational torque. These findings suggest that shock-absorbing compensatory mechanisms may be impaired in this group, highlighting the importance of foot posture assessment in rehabilitation following Anterior Cruciate Ligament Reconstruction.