Athletes with unilateral patellar tendinopathy have increased subsequent lower extremity musculoskeletal injury risk.

This study aimed to investigate static and dynamic postural balance inter-limb asymmetries in athletes with unilateral patellar tendinopathy (UPT) and estimate subsequent lower extremity musculoskeletal injury risk compared to controls. Twenty-eight athletes with UPT were recruited. Twenty-eight healthy athletes served as controls. Static postural balance inter-limb asymmetry (symmetry index: SI) was assessed based on differences in the mean center of pressure (CoP) velocity (CoPv) values between the affected leg (AL) and non-affected leg (NAL) for the UPT group, and the dominant leg (DL) and non-dominant leg (NDL) for controls. Outcome variables were dynamic postural balance, assessed with inter-limb asymmetry using the Y Balance Test (YBT), and injury risk. In static balance, SI values were significantly (P<0.001) higher in the UPT group compared to controls. In dynamic balance, normalized inter-limb asymmetry values were also significantly higher in athletes with UPT compared to controls in anterior (P<0.001), posteromedial (P<0.001) and posterolateral (P<0.01) directions, and in the composite score (P<0.001). Furthermore, the incidence of sustaining a non-contact lower extremity injury during the follow-up period (10 months) was significantly higher (P<0.05) in the UPT group compared to controls. Athletes with UPT had postural balance inter-limb asymmetries. Moreover, they had increased subsequent lower extremity musculoskeletal injury risk compared to controls. Since most athletes with UPT continue to train and compete, adequate training and rehabilitation programs should be implemented to prevent potential subsequent injury occurrence.