MEASURING PEAK ANGULAR VELOCITY OF KNEE EXTENSION DURING UNLOADED KICKING: A PILOT STUDY
Keywords:Isokinetic dynamometry, jump squat, f-v relationship
Journal of Sports Science and Physical Education 5(2): 9-14, 2016 - Jump squat tests can be used to investigate the differences in the force - velocity (f-v) profile in movement that is more a sport-specific than isolated exercises such as open chain leg extension. However, squat jumps involve multi-joint movement, making it questionable which muscle is the main contributor for the movement. The main aim of this study is to develop a test of isolated knee extension that encompasses the entire range of human f-v relationship and to investigate the correlation between linear encoder and kinematic measurement of angular velocity using a camera system during unloaded kicking. One healthy male subject volunteered to participate in the study and performed 10 unloaded kicks (knee extension). A cuff was strapped around the lower leg, approximately 2 cm above the medial malleoli and connected to a linear velocity encoder (MuscleLab Ergotest version 4010, Norway). During the test sessions, threedimensional motion analysis was performed with an Oqus Motion Capture System (Qualisys, Sweden). Data were transferred to Windows-based data acquisition software (Qualisys Track Manager). There was a positive linear relationship (r = 0.94). The unloaded kicking test to determine maximum angular velocity at knee extension measured using the QTM showed that the mean angular velocity was 362˚.s-1, with the highest value being 528˚.s-1. This preliminary study suggests isokinetic dynamometry (IKD) can be used to investigate the entire range of velocities (i.e isometric – velocity maximum) of knee extension in normal human subjects. Further studies can examine the use of IKD in measuring higher velocities.
Keywords: Isokinetic dynamometry, jump squat, f-v relationship