Abstract - Judo Performance Tests Using a Pulling Force Device Simulating a Seoi-Nage Throw
A pulling force device (PFD) is used to carry out monthly performance tests on 12 judo squad athletes (8 male, 4 female, aged 19.4 ± 4.3 years) of the Olympic Center in Linz (Austria) to see the progress over a training period of six months. The variation of a friction brake simulates the resistance of the opponent in the throwing technique Seoi-Nage, which consists of three phases: balance breaking (kuzushi), fit-in (tsukuri) and throw (kake). Force and velocity over time are measured, and the parameters maximum force Fmax, time to maximum force t(Fmax), maximum force derivative dFmax and maximum velocity vmax are calculated with use of the software LabView. Displaying force and velocity curves together with the recorded videos of a synchronous 2x 2D motion analysis in Dartfish in a special graphic user interface (GUI) provides a helpful visualization and feedback for athletes and trainer and shows imperfections in technical skills in more detail. The relevant investigations comprise the position of center of mass (COM), knee and elbow angles, body axis, trunk rotation as well as chain pullout. Longitudinal studies, standardized by weight category, show improvements in all 4 parameters, especially t(Fmax) has decreased by 64 %. The PFD has proven to be a valid method of determining specific abilities of judokas. The gained knowledge and experience will be used in optimizing individual motion structure and training. An improved, mobile PFD should also be used as a training device.