Psychological and pain processing factors in individuals with and without patellofemoral pain: sex differences and relationship with pain, function and quality of life

Abstract

Patellofemoral pain (PFP) is a multifactorial condition that involves mechanical and non-mechanical factors, such as psychological and pain processing (e.g., hyperalgesia). Elevated levels of kinesiophobia, pain catastrophizing, and hyperalgesia are present in mixed populations (male and female) of individuals with PFP. However, kinesiophobia, pain catastrophizing, and hyperalgesia differ between men and women in other musculoskeletal disorders. PFP is also characterized by sex differences, as evidenced by the higher incidence, prevalence, and biomechanical changes in women compared to men. To date, it has not been investigated whether levels of kinesiophobia, pain catastrophizing and hyperalgesia differ between men and women with and without PFP and whether these outcomes are related to pain, function, and quality of life in the same way in both sexes. Investigating these gaps may indicate whether specific assessments and interventions for psychological and pain processing factors should be tailored to the gender of participants. Objectives: to compare levels of kinesiophobia, pain catastrophizing, and pressure pain thresholds between men and women with and without PFP and to investigate whether these outcomes are related to pain, function, and quality of life in men and women with and without PFP. Methods: twenty-one men with PFP; 21 women with PFP; 21 men without PFP and 21 women without PFP, aged 18-40 years will be recruited for this cross-sectional study. The levels of kinesiophobia and pain catastrophizing will be assessed by the Tampa Scale of Kinesiophobia (TSK) and Pain Catastrophizing Scale (PCS), respectively. Hyperalgesia symptoms will be evaluated through pressure pain thresholds obtained with a digital algometer applied to the center of the patella and to the contralateral shoulder of the participants. The worst level of pain in the previous month will be assessed by the visual analog pain scale (VAS), self-reported function by the Anterior Knee Pain Scale (AKPS), and quality of life by the Medical Outcome Short-Form 36 (SF-36). One-way analysis of variance (two-way ANOVA) or corresponding non-parametric will be used for comparison between groups. Pearson or Spearman correlation coefficients will be used to investigate the relationships between outcomes.(AU)