Influence of symptom frequency and severity on hip abductor strength and endurance in individuals with patellofemoral pain

Abstract

Objective: To compare clinical measures of hip abductor strength and endurance of individuals with patellofemoral pain with more severe symptoms to those with less severe symptoms.

Design: Cross-sectional.

Settings: Laboratory.

Participants: Sixty participants with patellofemoral pain were divided three times into 2 groups according to three symptomatology criteria: functional capacity, pain frequency and pain severity.

Main outcome measures: Isometric strength evaluated using a hand-held dynamometer, endurance using maximum number of repetitions and maximum holding time, functional capacity using the Anterior Knee Pain Scale, pain frequency using a 2-category scale ("Less frequent" = 1-2 times a week; "More frequent" = >3 times a week) and pain severity using Numeric Pain Rating Scales.

Results: Participants with more frequent symptoms and with more severe pain were significantly weaker (10%, p = 0.04 and 16%, p = 0.001, respectively), and had less isometric (17%, p = 0.02 and 24%, p = 0.002, respectively) and dynamic (13%, p = 0.02 and 23%, p = 0.007, respectively) endurance compared to those with less pronounced symptoms.

Conclusion: Our study highlighted that hip abductor strength and endurance deficits are more pronounced in individuals with more severe and frequent pain.

Keywords: Knee; Muscle strength; Physical endurance; Symptomatology.