Identifying relationships among lower extremity alignment characteristics

Abstract

Context: The relationship between lower extremity alignment and lower extremity injury risk remains poorly understood, perhaps because most authors have examined only individual or a select group of alignment variables. Examining the relationships among alignment variables may allow us to more accurately describe lower extremity posture and clarify the relationship between lower extremity alignment and injury risk in future studies. Objective: To measure lower extremity alignment variables and examine whether relationships could be identified among these variables. Design: Observational study. Setting: Laboratory. Patients or Other Participants: Two hundred eighteen (102 males: age = 23.1 ± 3.2 years, height = 177.3 ± 8.4 cm, mass = 80.8 ± 13.0 kg; 116 females: age = 21.8 ± 2.7 years, height = 163.5 ± 7.4 cm, mass = 63.4 ± 12.4 kg) healthy, college-aged participants. Main Outcome Measure(s): We measured pelvic angle, femoral anteversion, quadriceps angle, tibiofemoral angle, genu recurvatum, and tibial torsion to the nearest degree and navicular drop to the nearest millimeter on the right and left lower extremities. Separate principal components factor analyses were performed for each sex and side (left, right). Results: A distinct lower extremity factor was identified, with relationships observed among increased pelvic angle, increased quadriceps angle, and increased tibiofemoral angle. A second distinct lower extremity factor was identified, with relationships observed among increased supine genu recurvatum, decreased tibial torsion, and increased navicular drop. Femoral anteversion loaded as an independent third factor. These distinct lower extremity alignment factors were consistent across side and sex. Conclusions: Factor analysis identified 3 distinct lower extremity alignment factors that describe the potential interactions among lower extremity alignment variables. Future authors should examine how these collective alignment variables, both independently and in combination, influence dynamic knee function and risk for lower extremity injuries. © by the National Athletic Trainers' Association, Inc.