Frontal and transverse plane hip and knee kinetics and kinematics during running in
individuals with PFPS
Jennifer Earl-Boehm1, David Bazett-Jones1, Mukta Joshi1, Philip Oblak1, Reed Ferber2, Carolyn
2
3
4
Emery , Karrie Hamstra-Wright , Lori Bolgla ,
1
2
3
University of Wisconsin-Milwaukee, Wisconsin, USA; University of Calgary, AB, CA; University of
Illinois-Chicago, Illinois, USA; 4 Georgia Health Sciences University, Augusta, GA, USA
email for correspondence: jearl@uwm.edu
Introduction
Weakness of the proximal hip musculature has been
1
found in individuals with PFPS , and is hypothesized to
lead to increased frontal and transverse plane motion of
the hip and knee. Alterations in frontal and transverse
plane kinematics of the hip and knee have been found in
individuals with PFPS, though findings have been
inconsistent. Kinematic changes have been found in
walking, running, and jump-landing.
However, few
studies have examined the hip and knee kinetics in
PFPS patients during similar tasks. Knee abduction
moment has been prospectively related to developing
PFPS2 and also related to developing patellofemoral joint
3
osteoarthritis . Furthermore, differences in hip and knee
kinetics during walking have also been noted between
those with and without PFPS 4 and peak knee abduction
moment decreases following a hip strengthening
5
6
intervention in both those with and without PFPS.
Therefore, the purpose of this project was to determine if
there are differences in frontal and transverse plane hip
and knee joint moments and angles during running
between individuals with and without PFPS.
Methods
As part of a larger RCT study, 25 men and women with
PFPS (Age 28.4±5.7yrs; Mass 70.2±13.9 kg; Height
1.73±8.7 m) participated in the study. The participants
met inclusion criteria that are common for PFPS research
(pain 3/10 for a minimum of 4 weeks; pain during
physical activity, prolonged sitting, jumping, squatting).
The control group consisted of 17 men and women (Age
29.4±7.9yrs; Mass 68.8±11.7 kg; Height 1.7±9.9 m)
who were free from any lower extremity injury and had no
history of PFPS or knee surgery. Both the PFPS and
control participants were active a minimum of 30 minutes
at least 3 times per week.
Baseline testing occurred prior to the initiation of any
rehabilitation exercises. For the PFPS participants the
most painful knee was tested, and this was matched for
the control participants. Three-dimensional kinematic
data were collected at 200 Hz and ground reaction force
data were collected at 1000 Hz. Participants ran at a
consistent speed (4.0-4.5 m/s) wearing standard
footwear, and after several practice trials, 5 trials were
recorded. Internal joint moments were calculated using
an inverse dynamics approach. Knee joint moments
were reported in the leg reference frame. Peak joint
angle and moment data were extracted from the stance
phase, and analyzed using repeated measures ANOVA
(p<0.05). The dependent variables analyzed were hip
and knee adduction and internal rotation angles, and hip
and knee abduction and external rotation moments. The
independent variable was group (PFPS or Control).
Results
There were no significant differences between PFPS and
control participants in any of the variables analyzed.
K Add angle
K Int Rot angle
H Add angle
H Int Rot angle
K Abd moment
K Ext Rot moment
H Abd moment
H Ext Rot moment
PFPS
1.4 ± 3.5
3.2 ± 5.6
12.4 ± 4.1
3.8 ± 4.9
-.96 ± .41
-.14 ± .08
-1.9 ± .29
-.06 ± .04
Control
2.8 ± 3.3
3.3 ± 6.1
11.7 ± 5.8
4.5 ± 5.7
-.88 ± .46
-.11 ± .08
-1.7 ± .47
-.10 ± .12
p
.241
.947
.668
.710
.588
.293
.189
.166
Discussion
While differences in knee abduction moment have been
seen during walking,4 no differences were seen during
running. Knee abduction moments in this study were
4
higher than those reported by Paoloni. Findings of this
study are also contrary to those of Stefanyshn,2 who did
report a significantly higher knee abduction impulse in
individuals with PFPS. No kinematic differences were
seen, as contributes to the contradictory nature of this
literature. However, knee abduction moment should
continue to be examined as it does appear to be
5,6
modifiable with strengthening. Future research should
continue to examine frontal plane knee mechanics, as
well as patellofemoral joint mechanics to further
understand the etiology of PFPS.
Acknowledgements
Funding support from the National Athletic Trainers’
Association Research and Education Foundation
References
1. Piva et al (2005) JOSPT, 35(12) 793-801.
2. Stefanyshn et al (2006) J Sports Med, 34(11) 18441851.
3. Maly et al (2008) Clin Biomech, 23(6) 796-805.
4. Paolini et al (2008) J Biomech, 43(9) 1794-1798.
5. Earl and Hoch (2011) AJSM, 39(1) 154-163.
6. Snyder et al (2009), Clin Biomech, 24(1) 26-34.