Correlation of knee joint laxity with bioimpedance parameters and bone frame size

femorotibial laxity plays a crucial role in knee stability, as increased laxity can raise the risk of injuries not only to the anterior cruciate ligament (ACL) but also to other key structures such as the posterior cruciate ligament (PCL) and the posteromedial and posterolateral corners. This study analyzed the factors associated with laxity in young individuals, as identifying the elements that influence this condition is essential for its prevention. The objective was to evaluate knee joint laxity in young people, considering factors such as sex, bone structure, body composition, and physical activity.

a total of 114 patients over 18 years old without any history of knee ligament injuries were included. Body composition was evaluated with the OMRON HBF-514c body composition monitor and scale. The ACL laxity was measured using the KNEELAX 3® arthrometer, while internal and external rotation was measured with PhidgetSpatial Precision inertial sensors. Physical activity was classified with Tegner scale while Lachman and Pivot Shift tests were performed as well as indicators of the ACL stability.

the mean age was 21.04 ± 2.2 years. Greater knee laxity (6.9 mm at 88N and 8.9 mm at 132N with p values of 0.047 and 0.001 respectively) and increased internal (28.7°) and external rotation (27.76°) were observed in women. ACL laxity was higher in individuals with smaller bone frame size (8.67 mm at 132N) and higher body fat percentage. In addition, participants with higher physical activity levels showed lower ACL laxity.

knee joint laxity was found to be greater in women, individuals with smaller bone frame size, and those with higher body fat percentage, which may increase the risk of injuries. Simultaneously, knee joint laxity was found to be lower in individuals with higher activity levels. It was concluded then that strengthening the musculature and making physical activity are essential for ligamentary injury prevention.