Patellofemoral pain subjects exhibit decreased passive hip range of motion compared to controls.

Background: Patellofemoral pain is a common condition without a clear mechanism for its presentation. Recently significant focus has been placed on the hip and its potential role in patellofemoral pain (PFP). The majority of the research has examined hip strength and neuromuscular control. Less attention has been given to hip mobility and its potential role in subjects with PFP.

Purpose/aim: The purpose of this study was to compare passive hip range of motion (ROM) of hip extension and hip internal and external rotation in subjects with PFP and healthy control subjects. The hypothesis was that subjects with PFP would present with less total hip ROM and greater asymmetry than controls.

Design: Two groups, case controlled.

Setting: Clinical research laboratory.

Participants: 30 healthy subjects without pain, radicular symptoms or history of surgery in the low back or lower extremity joints and 30 subjects with a diagnosis of PFP.

Main Outcome Measures: Passive hip extension, hip internal rotation (IR) and hip external rotation (ER). A digital inclinometer was used for measurements.

Results: There was a statistically significant difference (p<0.001) in hip passive extension between the control group and the PFP group bilaterally. Mean hip extension for the control group was 6.8° bilaterally. For the PFP group, the mean hip extension was -4.0° on the left and -4.3° on the right. This corresponds to a difference of means between groups of 10.8° on the left and 11.1° on the right with a standard error of 2.1°. There was no statistically significant difference (p>0.05) in either hip IR or ER ROM or total rotation between or within groups.

Conclusions: The results of this study indicate that a significant difference in hip extension exists in subjects with PFP compared to controls. These findings suggest that passive hip extension is a variable that should be included within the clinical examination of people with PFP. It may be valuable to consider hip mobility restrictions and their potential impact on assessment of strength and planned intervention in subjects with PFP.

Level Of Evidence: 2b.