Women with patellofemoral pain and knee crepitus have reduced knee flexion angle during stair ascent

Objectives: To compare trunk and knee biomechanics of women with and without patellofemoral pain (PFP) and knee crepitus during stair ascent. Design: Cross-sectional. Setting: Laboratory-based study. Participants: 29 women with PFP and knee crepitus (PFPCrepitus); 28 women with PFP and no knee crepitus (PFPNOCrepitus); 17 pain-free women with knee crepitus (Pain-free(Crepitus)); and 29 pain-free women without knee crepitus (Pain-free(NOCrepitus)). Main outcome measures: Peak trunk flexion, peak knee flexion, mean knee angular velocity, knee extensor moment at peak knee flexion, peak and impulse of the knee extensor moment. Results: PFPCrepitus group performed the stair ascent task with reduced peak knee flexion compared to Pain-free(Crepitus) (p = 0.04; Effect size = -0.85) and Pain-free(NOCrepitus) (p = 0.03; Effect size = -0.75). No significant differences among groups were found for peak trunk flexion (p = 0.979), knee angular velocity (p = 0.420), knee extensor moment at peak knee flexion (p = 0.933), peak (p = 0.290) and impulse (p = 0.122) of the knee extensor moment. Conclusion: Women with concomitant PFP and knee crepitus demonstrated reduced knee flexion during stair ascent, but no significant differences for trunk flexion and knee extensor moment variables were found. (C) 2020 Elsevier Ltd. All rights reserved.