Lower extremity kinematics of females with patellofemoral pain syndrome while stair stepping

J Orthop Sports Phys Ther. 2010 Oct;40(10):625-32. doi: 10.2519/jospt.2010.3185.


Study design: Cross-sectional case-control design.

Background: Although the etiology of patellofemoral pain syndrome (PFPS) is not completely understood, there is some evidence to suggest that hip position during weight-bearing activities contributes to the disorder.

Objective: To compare the knee and hip motions (and their coordination) during stair stepping in female athletes with and without PFPS.

Methods: Two groups of female recreational athletes, 1 group with PFPS (n = 10) and a control group without PFPS (n = 10), were tested. All participants ascended and descended stairs (condition) at 2 speeds (self-selected comfortable and taxing [defined as 20% faster than the comfortable speed]), while the knee and hip angles were measured with a magnetic-based kinematic data acquisition system. Angle-angle diagrams were used to examine the relationship between flexion/extension of the knee and flexion/extension, adduction/abduction, and internal/external rotation of the hip. The angle of the knee and the 3 angles of the hip at foot contact on the third step were compared between groups by means of 3-way analyses of variance (ANOVA), with repeated measures on speed and condition.

Results: Group-by-speed interaction for knee angle was significant, with knee flexion being greater for the PFPS group for stair ascent and descent at a comfortable speed. Both the angle-angle diagrams and ANOVA demonstrated greater adduction and internal rotation of the hip in the individuals with PFPS compared to control participants during stair descent.

Conclusion: Compared to control participants, females with PFPS descend stairs with the knee in a more flexed position and have the hip in a more adducted and internally rotated position at foot contact during stair stepping at a comfortable speed.

MeSH terms

  • Adult
  • Biomechanical Phenomena*
  • Case-Control Studies
  • Cross-Sectional Studies
  • Female
  • Humans
  • Lower Extremity / physiology*
  • Patellofemoral Pain Syndrome / physiopathology*
  • Range of Motion, Articular
  • Young Adult