Interception of moving objects in karate: an experimental, marker-free benchmark

Abstract

SummaryBackground: karate requires an optimal interception of the opponent's attack. Particularly in unconstrained situations, normal, untrained, subjects solve this problem adopting rather different solutions. It is currently unknown if karate as show a more uniform selection of interception schemes due to their special training. Methods: here we applied a 3D scanner to study the movement reproducibility of skilled karate as in a natural setup, using an unconstrained interception task. Six right handed karatekas and six controls participated to the study. 3D motion tracking data of the upper limbs were obtained using the Microsoft Kinect sensor, a real-time 3D scanner. The interception task consisted of intercepting and stopping a moving stick which was directed towards the side of the subject in two different positions (upper and lower). Results: the analysis of hand trajectories showed that the strategy of the movement was remarkably different between control subjects, whereas it was more uniform in karatekas. Moreover, we observed a significant difference in the variability of the interception point between control subjects and karatekas. Conclusion: the results confirm the presence of individual idiosincratic behavior in interception tasks also in ecologically realistic situations, and that experience and training (as in karatekas) play an important role in the trajectory in interceptive tasks.

In-Home Posture Evaluation and Visual Feedback Training to Improve Posture with a Kinect-Based System in Parkinson’s Disease

“…These systems should be easy to install and easy for the individual to use by him-or herself at home. Several trials using game devices such as Kinect (Microsoft Corp.) for the assessment of postural control and dynamic movement and rehabilitation for improving postural control have been reported [13][14][15][16][17][18]. Recently, accuracy of Kinect to measure posture in Parkinson's disease was confirmed by simultaneously recording standing postures with Kinect and the motion capture system and comparing these results in the experimental setting [16].…”