Etiologic factors associated with anterior knee pain in distance runners.
OBJECTIVE
The objectives of this study were 1) to examine the differences between a noninjured (C) cohort of runners (N = 70) and runners afflicted with anterior knee pain (AKP) according to selected training, anthropometric, rearfoot motion, ground reaction force, and muscular strength and endurance variables; 2) to explore multivariate relationships among these measures in the well and injured groups; and 3) to develop specific hypotheses concerning risk factors for injury that will later be tested in a prospective clinical study.


METHODS
High speed videography (200 frames x s(-1)), a force platform (500 Hz), and a Cybex II+ isokinetic dynamometer were used to assess rearfoot motion, ground reaction forces, and knee muscular strength and endurance, respectively. A linear discriminant function was performed on each of the five categories of variables and revealed 19 significant (P < or = 0.05) predictors. These variables were then combined and a final discriminant function analysis was performed.


RESULTS
Pronation through the first 10% of stance, arch index, shoe mileage, and extension peak torque were the best overall (P < or = 0.05) predictors. The AKP group had smaller mean values on all four significant predictors.


CONCLUSIONS
With the exception of shoe mileage, which is likely a response to rather than a risk factor for AKP, these results should prove useful to clinicians in identifying runners at risk for anterior knee pain.
Duffey
M J
MJ
Department of Health and Exercise Science, Wake Forest University, Winston- Salem, NC 27109, USA.
Martin
D F
DF
Cannon
D W
DW
Craven
T
T
Messier
S P
SP
D000328:Adult; D001696:Biomechanical Phenomena; D017079:Exercise Tolerance; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000209:etiology*; D008297:Male; D009068:Movement; D018482:Muscle, Skeletal / Q000502:physiology; D010146:Pain / Q000209:etiology*; D010809:Physical Fitness; D012420:Running / Q000293:injuries*