Never Skip Leg Day Again: Training the Lower Body with Vertical Jumps in a Virtual Reality Exergame

Title of the Paper

Never Skip Leg Day Again: Training the Lower Body with Vertical Jumps in a Virtual Reality Exergame

Paper Information

• Subject Area: Research on the integration of physical movement and health in Virtual Reality (VR), with a focus on lower body training.
• Keywords: Virtual Reality, VR, motion-based games, vertical jump training, exercise, health, dynamic difficulty, serious games

Research Background and Problem

• Identified Problem: Most existing VR motion-based games primarily focus on upper body training, neglecting lower body exercises. However, lower body training is crucial for physical coordination, stability, and injury prevention. Additionally, explosive movements (e.g., jumping) pose high risks, and current VR technology may lack precision in tracking such movements.
• Significance: Lower body training helps prevent muscle imbalances and injury risks caused by prolonged sitting, while also enhancing physical stability and coordination. VR motion-based games have the potential to serve as an alternative for at-home fitness solutions.
• Research Motivation: The authors aim to fill the gap in current motion-based game design by developing a VR-based vertical jump training game, exploring the technical feasibility and user experience of full-body movement.

Solution

• Methods and Solutions:

  • Developed a VR-based vertical jump training game called JumpExTra VR.
  • Designed the game and technical solutions based on literature review and feedback from nine experts in sports science, physical therapy, and related fields.
  • The game consists of four levels with progressively increasing training intensity: foot tapping, hopscotch, obstacle dodging, and maximum vertical jump training.
  • Utilized the Vive Pro headset and Vive Trackers to track body movements.
  • Provided real-time feedback on user movements to help optimize techniques, adjust actions, and prevent potential injuries.
  • Introduced a dynamic difficulty adjustment mechanism to accommodate players' skill levels and physical abilities.

• Innovations:

  • Proposed vertical jump training as a specific application of full-body VR exercise.
  • Designed a comprehensive game mechanism incorporating progressive training, personalized feedback, and dynamic difficulty adjustment, based on expert feedback and literature.
  • Innovatively used VR hardware tracking errors as an indicator for soft landing quality assessment.

• Implementation Steps and Key Technologies:

  • Gathered requirements through literature review and expert interviews.
  • Designed and implemented the game, including motion data collection, scene design, and workflow.
  • Conducted user research and analysis through exploratory experiments to collect user data and feedback.
  • Summarized design guidelines to inform future development of full-body VR motion-based games.

Research Outcomes

• Specific Results:

  • Developed JumpExTra VR, which integrates rhythm training, motion coordination training, and technique correction functionalities.
  • Experiments demonstrated the game's effectiveness in enhancing user challenge and enjoyment, with potential for improving users' movement techniques.
  • Summarized five design guidelines: avoiding unintended forward drift, considering technical limitations, addressing safety issues in full-body movements, incorporating rhythm elements to ensure smooth motion, and dynamically adjusting difficulty based on player fitness levels.

• Advantages:

  • Full-body exercise provides more balanced physical training.
  • The game's dynamic difficulty adjustment and personalized feedback make it appealing to users of varying skill levels.
  • User research revealed its potential for long-term engagement.

• Experimental or Evaluation Results:

  • Users achieved an average success rate of 60%-90% in the rhythm training module, as expected.
  • While users' vertical jump height did not significantly improve, their jump technique scores increased from 71.45% to 75.45%.
  • Overall game experience and physical activity ratings were high, with users particularly praising the technical feedback and rhythm design.

• Limitations and Future Directions:

  • Current hardware tracking precision affects the accuracy of jump analysis, requiring further validation of research outcomes.
  • Game difficulty level distribution needs optimization to better match user abilities.
  • The long-term effectiveness of maintaining user interest in the game remains unverified.
  • Hardware requirements (e.g., additional Vive Trackers) limit the game's accessibility.

Future Directions:

1. Evaluate the long-term effects of using JumpExTra VR to understand its impact on behavioral habits.
2. Compare the effectiveness of JumpExTra VR with traditional training programs.
3. Explore new design solutions to improve user retention in the technical training module.
4. Adapt the game structure to leverage advancements in future VR hardware technology.

Main Contributions of the Paper

1. Summarized the technical requirements and challenges of VR vertical jump training.
2. Created a VR motion-based game prototype focused on lower body training.
3. Validated the feasibility of the game through user research and collected user feedback.
4. Proposed five core design guidelines for the development of full-body VR motion-based games.