علی رضا پورمقدم

  The aim of this study was to investigate the relationship between dynamic knee valgus angle (DKV) during three motor tasks: single-leg squat (SLS), single-leg landing (SLL), and double-leg jumps and landings (DVJ) with a recreational set of functions including trunk control, hip and knee strength, postural function, and dorsiflexor range of motion. The present descriptive-correlation study was conducted on ۲۸ subjects aged ۱۸ to ۲۵ years. Kinematic data were collected with ۲D video analysis using Kinovea software, and functional data were collected with standard tests including hand-held dynamometer, comparison test, and launch test. Statistical analysis included Pearson and Spearman correlation tests, analysis of variance with Muir or Friedman measurements, and multiple regression. The results showed that the valgus angle was lower in the SLL task and the lowest in the DVJ task, and the difference between the differences between some tasks was significant. In examining the relationships, in the SLL task, trunk flexion and extension torque, hip external rotation torque, and Y-Balance test score were significantly correlated with DKV. In DVJ, only ankle dorsiflexion range showed a significant relationship with DKV. In SLS, no relationship was observed. The results of multiple regression also indicated that no change alone was able to predict DKV change in all tasks. Overall, the findings indicate a multifactorial DKV that is influenced by multiple biomechanical and neuromuscular factors. These important results indicate the simultaneous attention to control, hip function, knee strength, ankle and inter-postural range of motion in the design of preventive and rehabilitation exercises. Also, tasks using higher performance such as SLL can be used for screening and injury, which can be better in identifying functional functions.