Implications of knee crepitus to the overall clinical presentation of women with and without patellofemoral pain

Objectives: Compare anthropometric characteristics, function, kinesiophobia, catastrophism and knee extensor strength between women (i) with PFP and crepitus (PFPcrepitus); (ii) with PFP and no crepitus (PFPNOcrepitus): (iii) without PFP and crepitus (Pain-freecrepitus); and (iv) without PFP and no crepitus (Pain-free(NOcrepitus)). Design: Cross-sectional. Setting: Laboratory study. Participants: 65 women with PFP and 51 pain-free women. Main outcome measures: Objective assessment of knee crepitus, forward step-down and single leg hop tests; knee extensor strength tests; and subjective ratings of function, kinesiophobia, pain catastrophising and knee stiffness. Results: Crepitus was more common in women with PFP (50.7%) compared to those without (33.3%) (v2(1) 4.17; p = 0.031). PFPcrepitus and PFPNOcrepitus groups had lower self-reported function; and higher, kinesiophobia, catastrophism and knee stiffness compared to Pain-freecrepitus and Pain-free(NOcrepitus) groups (p <0.001). PFPcrepitus, PFPNOcrepitus and Pain-freecrepitus groups had lower functional performance compared to the Pain-freeNocrepitus group (p <0.040). PFPcrepitus and PFPNOcrepitus groups had lower isometric, concentric and eccentric knee extensor strength compared to the pain-free(NOcrepitus) group (p < 0.041), but not the pain-freecrepitus group. PFPcrepitus presented higher BMI than other groups (p = 0.001). Conclusion: Kinesiophobia, catastrophism, knee stiffness, strength and physical function are all impaired in women with PFP, regardless of crepitus. In pain-free women, crepitus was associated with poorer objective function. (C) 2018 Elsevier Ltd. All rights reserved.