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

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.