Lower extremity strength and mechanics during jumping in women with patellofemoral pain.
BACKGROUND
Lower extremity (LE) weakness might be associated with altered mechanics during weight bearing in subjects with patellofemoral pain syndrome (PFPS).


OBJECTIVE
To analyze LE strength, mechanics, and the association between these variables among women with and without PFPS during a simulated athletic task.


METHODS
Case control.


METHODS
Motion-analysis laboratory.


METHODS
20 women with PFPS and 20 healthy women.


METHODS
Peak isometric lateral trunk-flexion, hip-abduction, hip external-rotation, knee-flexion, and knee-extension strength, as well as hip- and knee-joint excursions and angular impulses during single-leg jumps.


RESULTS
PFPS subjects produced less hip-abduction, hip external-rotation, and trunk lateral-flexion force than the control group. The PFPS group also demonstrated greater hip-adduction excursion and hip-abduction impulses. The association between the strength measurements and LE mechanics was low.


CONCLUSIONS
Women with PFPS demonstrate specific weaknesses and altered LE mechanics. Weakness is not, however, highly correlated with observed differences in mechanics.
Willson
John D
JD
Physical Therapy Program, University of Wisconsin-LaCrosse, LaCrosse WI 54601, USA.
Davis
Irene S
IS