Tennis Motion Learning in Virtual Reality

Tennis, as an international sport, has health benefits when performed correctly. However, the overuse of poor technique raises the risk of injuries, such as tennis elbow. Appropriate training routines, instructions on proper technique, and early error correction are crucial steps to injury prevention and beneficial to performance. However, regular tennis training takes effort and motivation and is impeded by limited resources such as available tennis courts, professional coaches, and the associated financial and time commitments. These challenges raise interest in accessible solutions that facilitate regular, short practice sessions, aid motor learning, and effectively complement traditional coaching methods.This thesis presents a novel method for self-training a correct tennis forehand technique through target practice in virtual reality (VR). Our method provides immediate post-action multimodal feedback on a user's technique by utilizing partial motion tracking of the VR headset and controllers combined with automated, expert-driven motion analysis. Each captured forehand stroke is segmented into individual phases based on defined motion features. Specific aspects of tennis technique associated with these phases are analyzed using coaching rules established in traditional coaching. After each shot, users receive auditory and visual feedback, concentrating on one coaching rule at a time. This feedback delivers timely corrections on identified mistakes and positively reinforces technical improvements. A motion replay accompanies the provided information to facilitate self-monitoring and reflection.Using a within-group pretest-posttest design, we evaluated our VR forehand tennis training in a supervised user study with 26 participants. A comparison of performance metrics measured before and after a 10-minute VR training session revealed significant improvements in participants' technique, indicating a potential short-term learning effect. Questionnaire responses demonstrate significant improvements in participants' motivation to play tennis and confidence in their tennis technique from the pre-test to the post-test. A qualitative analysis further highlights both the strengths and limitations of our method. Participants expressed the belief that our approach to VR tennis training can complement traditional coaching.