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 (PFP); 28 women with PFP and no knee crepitus (PFP); 17 pain-free women with knee crepitus (Pain-free); and 29 pain-free women without knee crepitus (Pain-free).

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: PFP group performed the stair ascent task with reduced peak knee flexion compared to Pain-free (p = 0.04; Effect size = -0.85) and Pain-free (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.