Background: Preventing anterior cruciate ligament(ACL) injuries is very important for athletes, and dynamic knee valgus is considered a risk factor for non-contact ACL injury. However, little is known about whether...Background: Preventing anterior cruciate ligament(ACL) injuries is very important for athletes, and dynamic knee valgus is considered a risk factor for non-contact ACL injury. However, little is known about whether the functions of the hip abductor and rear-foot increase dynamic knee valgus. A two-dimensional(2D) video-based screening test focused on hip abductor and rear-foot functions among factors involved in dynamic knee valgus. The present study determined associations between hip and rear-foot dynamic alignment and dynamic knee valgus.Methods: This cross-sectional study recruited 130 female basketball players(258 legs) from nine high-school teams. The players performed single-leg squats and single-leg drop landings to provide knee-in(KID) and hip-out(HOD) distances on 2D video images. Hip and rear-foot dynamic alignment was evaluated using a dynamic Trendelenburg test(DTT) and a dynamic heel-floor test(HFT).Results: The Chi-square test revealed no significant difference in the prevalence of DTT-positivity between single-leg squats(28.7%) and singleleg drop landings(23.3%). The prevalence of HFT-positivity was significantly greater during landings(51.4%) than during single-leg squats(31.0%, p 〈 0.01). The KID values for both single-leg squats and single-leg drop landings were greater in the DTT-positive than in the DTTnegative group(15.1 5.4 cm and 20.2 7.5 cm, p 〈 0.001). The HOD values were similarly greater in the DTT-positive group(15.2 1.9 cm and 17.6 2.8 cm, p 〈 0.001). The KID values for both single-leg squats and single-leg drop landings were greater in the HFT-positive than in the HFT-negative group(12.2 5.1 cm, p 〈 0.01; 14.7 7.2 cm, p 〈 0.001), whereas HOD values for these tasks did not significantly differ between the two groups.Conclusion: Dynamic hip mal-alignment might be associated with both greater KID and HOD, whereas rear-foot eversion is associated only with greater KID. Hip abductor and rear-foot dysfunction are important factors for dynamic knee valgus and thus evaluating DTT and HFT will help to prevent dynamic knee valgus.展开更多
文摘Background: Preventing anterior cruciate ligament(ACL) injuries is very important for athletes, and dynamic knee valgus is considered a risk factor for non-contact ACL injury. However, little is known about whether the functions of the hip abductor and rear-foot increase dynamic knee valgus. A two-dimensional(2D) video-based screening test focused on hip abductor and rear-foot functions among factors involved in dynamic knee valgus. The present study determined associations between hip and rear-foot dynamic alignment and dynamic knee valgus.Methods: This cross-sectional study recruited 130 female basketball players(258 legs) from nine high-school teams. The players performed single-leg squats and single-leg drop landings to provide knee-in(KID) and hip-out(HOD) distances on 2D video images. Hip and rear-foot dynamic alignment was evaluated using a dynamic Trendelenburg test(DTT) and a dynamic heel-floor test(HFT).Results: The Chi-square test revealed no significant difference in the prevalence of DTT-positivity between single-leg squats(28.7%) and singleleg drop landings(23.3%). The prevalence of HFT-positivity was significantly greater during landings(51.4%) than during single-leg squats(31.0%, p 〈 0.01). The KID values for both single-leg squats and single-leg drop landings were greater in the DTT-positive than in the DTTnegative group(15.1 5.4 cm and 20.2 7.5 cm, p 〈 0.001). The HOD values were similarly greater in the DTT-positive group(15.2 1.9 cm and 17.6 2.8 cm, p 〈 0.001). The KID values for both single-leg squats and single-leg drop landings were greater in the HFT-positive than in the HFT-negative group(12.2 5.1 cm, p 〈 0.01; 14.7 7.2 cm, p 〈 0.001), whereas HOD values for these tasks did not significantly differ between the two groups.Conclusion: Dynamic hip mal-alignment might be associated with both greater KID and HOD, whereas rear-foot eversion is associated only with greater KID. Hip abductor and rear-foot dysfunction are important factors for dynamic knee valgus and thus evaluating DTT and HFT will help to prevent dynamic knee valgus.