The Effects of Sex, Limb Dominance, and Soccer Participation on Knee Proprioception and Dynamic Postural Control

Context: Both female athletes' participation in soccer and associated injuries have greatly increased in recent years. One issue is the 2-9 times greater incidence of noncontact anterior cruciate ligament (ACL) injuries in female athletes relative to male athletes in comparable sports. Several factors such as limb dominance and sporting history have been proposed to play a role in ACL incidence rates between male and female athletes. However, evidence about the effects of these factors and how they interact with sex is mixed, and thus no consensus exists. Objective: To quantify the effects of sports participation, limb dominance, and sex on dynamic postural control and knee-joint proprioception. Design: Cross-sectional study. Setting: University research laboratory. Participants: 19 male soccer players, 17 female soccer players, 19 sedentary men, and 18 sedentary women. Intervention: Joint-position sense was tested using reproduction of passive positioning on a Biodex isokinetic dynamometer (30 degrees, 45 degrees, and 60 degrees from 90 degrees of knee flexion). Three Star Excursion Balance Test directions were used to assess dynamic postural control. Main Outcome Measure: Normalized reach distance (% of leg length) in the anterior, posteromedial, and posterolateral directions on each leg quantified dynamic postural control. Average absolute error and constant error for both limbs quantified joint-position sense. Results: Posteromedial reach distance was significantly better in soccer players than sedentary individuals (P=.006). Anterior reach distance was significantly better (P=.04) in sedentary individuals than soccer players. No limb-dominance or sex differences were identified for dynamic postural control, and no differences in absolute-or constant-error scores were identified. Conclusion: Sporting history has a direction-specific impact on dynamic postural control. Sporting history, sex, and limb dominance do not influence knee-joint proprioception when tested in an open kinetic chain using passive repositioning.