The study objective is to test general-and sport-specific adaption during a single training on the Flexibility Trainer. The device is designed to trigger residual muscle tone decreases of the hip-joint muscles by providing (nearly) isokinetic resistance during a full range of motion strength training in adduction/abduction and flexion/ extension direction. Static hip flexion and abduction as well as kinematics of double side kicks were analysed on 15 participants before and after training (or rest for controls) to assess general flexibility and sport-specific movement range. Tests were recorded by a Vicon® motion capturing system. Static hip flexion and abduction as well as leg vector spreading angles (VSA) at different nodes of the kick were selected to determine adaptions of active and passive flexibility. Normalised hip joint moments, movement velocities and VSA were calculated to evaluate the training with the device. ANOVAs with 4-repeated measures and Friedman tests were performed to identify time differences and Bonferroni post-hoc test to identify betweensubject effects. Significant differences were found for both static flexibility tests (Flexion = 13.65%; Abduction = 9.94%) and the VSA at specific action phases (≤15.15%). Results indicate that short-term adaptions when training with the Flexibility Trainer are exceeding comparable literature showing improved flexibility and sportspecific performance.

A technique in Martial Arts is often indicated by an athlete's preceding actions, which potentially enables an opponent to detect or counter it. Prior to kicks, fighters attain balance and ease leg elevation by re-distributing their weight (WRT) or ease following sequences by elevating COM (CET). The aim of this study was to define such movements and to compare them by their duration and motion amplitude. The kick preceding actions and regular fighting movements of a kicking combination performed by 44 fighters across different skill levels (advanced to world leading) were compared. The initiation action start was determined by the moment during the preparatory phase, when a joint angle significantly exceeds or subceeds a specific threshold (3Sd). Descriptive statistics and qualitative analysis were used to summarise movement types, durations, and amplitudes. T-and Wilcoxon tests were performed to analyse differences in movement start and amplitude between WRT and CET, while Friedman-and Dunn-Bonferroni tests were used between body segments. Results showed that WRTs start earlier, happen more often, and are more subtle than CETs. Furthermore, proximal segments tend to move earlier [Sequence: COM; torso; hips> arms; knees] and with less movement amplitude [Sequence: arms > hips; knees > torso].

Emerging smart devices have gathered increasing popularity within the sports community, presenting a promising avenue for enhancing athletic performance. Among these, the Rise Dynamics Alpha (RD α) smart gloves exemplify a system designed to quantify boxing techniques. The objective of this study is to expand upon the existing RD α system by integrating machine-learning models for striking technique and target object classification, subsequently validating the outcomes through empirical analysis. For the implementation, a data-acquisition experiment is conducted based on which the most common supervised ML models are trained: decision tree, random forest, support vector machine, k-nearest neighbor, naive Bayes, perceptron, multi-layer perceptron, and logistic regression. Using model optimization and significance testing, the best-performing classifier, i.e., support vector classifier (SVC), is selected. For an independent evaluation, a final experiment is conducted with participants unknown to the developed models. The accuracy results of the data-acquisition group are 93.03% (striking technique) and 98.26% (target object) and for the independent evaluation group 89.55% (striking technique) and 75.97% (target object). Therefore, it is concluded that the system based on SVC is suitable for target object and technique classification.