E. Witvrouw et al., Intrinsic risk factors for the development of anterior knee pain in an athletic population - A two-year prospective study, AM J SP MED, 28(4), 2000, pp. 480-489
Many variables have retrospectively been associated with the presence of an
terior knee pain. Very few prospective data exist, however, to determine wh
ich of these variables will lead to the development of anterior knee pain.
It was our purpose in this study to determine the intrinsic risk factors fo
r the development of anterior knee pain in an athletic population over a 2-
year period. Before the start of training, 282 male and female students enr
olled in physical education classes were evaluated for anthropometric varia
bles, motor performance, general joint laxity, lower leg alignment characte
ristics, muscle length and strength, static and dynamic patellofemoral char
acteristics, and psychological parameters. During this 2-year follow-up stu
dy, 24 of the 282 students developed patellofemoral pain. Statistical analy
ses revealed a significant difference between those subjects who developed
patellofemoral pain and those who did not concerning quadriceps and gastroc
nemius muscle flexibility, explosive strength, thumb-forearm mobility, refl
ex response time of the vastus medialis obliquus and vastus lateralis muscl
es, and the psychological parameter of seeking social support. However, onl
y a shortened quadriceps muscle, an altered vastus medialis obliquus muscle
reflex response time, a decreased explosive strength, and a hypermobile pa
tella had a significant correlation with the incidence of patellofemoral pa
in, We concluded that the latter four parameters play a dominant role in th
e genesis of anterior knee pain and we therefore deem them to be risk facto
rs for this syndrome.