Dynamic postural control during step down task in patients with patellofemoral pain syndrome

[Purpose] This study aimed to examine the differences in dynamic postural control during forward step down (FSD) task in patients with patellofemoral pain syndrome (PFPS). [Participants and Methods] Sixty-eight participants (34 males and 34 females) were divided into the following 2 groups: 34 PFPS patients (17 males and 17 females) and 34 healthy controls (17 males and 17 females). Each participant performed FSD task from a height of 20 cm. A force platform was used to extract the center of pressure parameters during FSD task for calculation of time to stabilization (TTS) in the anterior-posterior (A/P) and medial-lateral (M/L) direction. [Results] PFPS group took longer time to stabilize than the healthy control group in A/P and M/L directions. A main effect for direction was found, and this indicated that the A/P TTS of 8.43 ± 0.79s was longer than the M/L TTS of 5.56 ± 1.95s in healthy participants and A/P TTS of 9.09 ± 0.82s was longer than the M/L TTS of 7.15 ± 2.11s in PFPS. [Conclusion] These findings suggest that dynamic postural control can be affected in PFPS patients.