Objective: To determine the extent to which select lower extremity alignment characteristics of the pelvis, hip, knee, and foot are related to the Q angle.
Design: Descriptive cohort study design.
Setting: Applied Neuromechanics Research Laboratory.
Participants: Two hundred eighteen participants (102 males, 116 females).
Assessment of Risk Factors: Eight clinical measures of static alignment of the left lower extremity were measured by a single examiner to determine the impact of lower extremity alignment on the magnitude of Q angle.
Main Outcome Measures: Q angle, pelvic angle, hip anteversion, tibiofemoral angle, genu recurvatum, tibial torsion, navicular drop, and femur and tibia length.
Results: Once all alignment variables were accounted for, greater tibiofemoral angle and femoral anteversion were significant predictors of greater Q angle in both males and females. Pelvic angle, genu recurvatum, tibial torsion, navicular drop, and femur to tibia length ratio were not significant independent predictors of Q angle in males or females.
Conclusions: Greater femoral anteversion and tibiofemoral angle result in greater Q angle, with changes in tibiofemoral angle having a substantially greater impact on the magnitude of the Q angle compared with femoral anteversion. As such, the Q angle seems to largely represent a frontal plane alignment measure. As many knee injuries seem to result from a combination of both frontal and transverse plane motions and forces, this may in part explain why Q angle has been found to be a poor independent predictor of lower extremity injury risk.
From the *Applied Neuromechanics Research Laboratory, University of North Carolina at Greensboro, Greensboro, North Carolina; †Department of Athletic Training and Physical Therapy, University of North Florida, Jacksonville, Florida; and ‡Department of Public Health Education, University of North Carolina at Greensboro, Greensboro, North Carolina.
Submitted for publication October 8, 2008; accepted February 19, 2009.
Funded in part by NIH-NIAMS # R01 AR053172.
The authors state that they have no financial interest in the products mentioned within this article.
Reprints: Anh-Dung Nguyen, PhD, ATC, University of North Carolina at Greensboro, 237 HHP Bldg, 1408 Walker Ave, Greensboro, North Carolina 27412 (e-mail: firstname.lastname@example.org).