The Comparison of Selective EMG Indicators of Thigh in Athletes with and Without Limited Ankle Dorsiflexion in a Single-Leg Jump Task

The aim of this study was to compare knee muscle onset, feedforward, feedback and pattern of the activity in colligate athletes who suffer from limited ankle dorsiflexion range of movement in a single leg jump landing task. 30 subjects from basketball, volleyball and handball participated in this study and were divided into 2 control and experimental groups. In a single leg jump landing task, the onset and amplitude activity of Vastus Lateralis Oblique (VLO), Vastus Medialis Oblique (VMO), Rectus Femoris (RF), Bicep Femoris (BF) and Semi Tendenisous (ST) were measured using surface electromyography. The results show that there were no significant differences for onset, feedfowrad, feedback and amplitude activity of the selected knee muscles between the control and experimental group. Although the theory of closed chain kinematics declares that if there is a defect in one of the kinematic chains other chains would be influenced as in muscle activity, but the current study shows that there were no significant difference between the feedforward, feedback, amplitude and onset activation for knee muscles between athletes with and without limited ankle dorsiflexion range of motion.