A wearable device to help youth players in volleyball games
VolleyEase
Personal Project (Summer 2025)
VolleyEase is a wearable concept for youth volleyball players, designed to support the final 10–20 minutes of a match. It combines fatigue monitoring with quick interventions like compression, vibration, and cooling to help players recover faster, stay focused, and reduce injury risks.
Inspiration
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I love volleyball for the intense amount of teamwork that is need to be able to play the sport at a high performance. No single person is able to carry the entire team on their own. Without good receivers, the setter will never get the chance to set to give the hitters a chance to hit. Every part of the team has to work as one well-oiled machine.
As a setter, I am involved in almost every single “play” thus I needed to be able to work well with every person on the team. Learning each hitters’ preferences and then seeing the work pay off when we win a point feels extremely rewarding and is why I love the sport so much.
As the game nears the end and the players get tired, the teamwork can sometimes fall apart. Mistake get made, people get frustrated and morale can start to falter. During such a crucial point in play, it is paramount that something like this doesn’t happen, which is where the inspiration for this project originates from.
Background research
Over the past two decades, volleyball, as a global sport, has seen steady growth among youth. The International Volleyball Federation (FIVB) estimates that in 2022, approximately 800 million people worldwide participated in volleyball, making it one of the most widely participated team sports in the world.
With the continuous improvement of school sports and youth club systems, the number of youth volleyball participants worldwide is continuously increasing, gradually showing a pattern of global adoption and regional development.
According to the National Federation of High School Sports (NFHS), approximately 548,000 students participated in volleyball in US high schools in the 2022–23 school year, making volleyball one of the most popular interscholastic sports in the country.
User journey map
Design concept
Interview
Q1: What physical changes typically occur in the final 10–20 minutes of a match?
A1: "Usually, my breathing becomes rapid and my legs feel noticeably sore. I feel like I'm draining my energy faster than usual, sometimes my jump height drops significantly, and my spiking power isn't as strong as in the first half."
Q2: Do you experience any special mental changes?
A2: "I'm under a lot of pressure, and I worry about making mistakes. Sometimes, nervousness causes me to lose focus, which can lead to distorted receiving movements and even simple errors."
Q3: If there were an assistive device or tool, what problem would you most like it to solve?
A3: "I'd like something that can help me recover quickly, even temporarily, by relaxing my legs and allowing me to breathe more freely. Also, it could help me stay focused and calm down during crucial moments."
Q1: What concerns do you have about your players in the final 10–20 minutes?
A1: "There are two main ones: one is a decline in physical fitness, such as a decrease in jumping height and reaction speed; the other is a mental breakdown, which can lead to unnecessary mistakes during crucial moments."
Q2: What measures do you take on the field?
A2: "I try to adjust the situation through substitutions and timeouts. I also use timeouts to calm the players and remind them to execute the tactics instead of just focusing on the score."
Q3: If a wearable device could provide real-time insights into your players' performance, which data would you be most interested in?
A3: "I'd most like to see heart rate and fatigue level. If there were simple signals that could indicate which players are nearing their limits, I could make substitutions or adjustments more quickly. It would also be helpful to have an indicator of psychological stress, such as an early warning when they're feeling nervous."
Insight-HMW
Fatigue Identification
Fatigue Identification How Might We helps players identify their fatigue levels in real time during the final 10–20 minutes without affecting their game action? How Might We visually communicates player fatigue data to coaches so they can make timely tactical adjustments?
Injury Risk Mitigation
How Might We provides quick micro-interventions (cold compresses, compression, vibration) to players' knees or legs to reduce the risk of strains or sprains? How Might We allows players to recover briefly without interrupting play, thereby reducing overuse injuries?
Relaxation Aid
Focus Enhancement
How Might We uses subtle sensory cues (vibration, light signals) to remind players to stay focused and reduce crucial mistakes. How Might We translates physiological signals of psychological stress into simple feedback to help players regulate their breathing rhythm.
How Might We uses 30-second interventions (vibration, hot and cold switching) during timeouts or breaks to quickly relieve muscle tension. How Might We allows players to use the same device for immediate recovery after a game, maintaining a consistent experience both on and off the court.
Fabrications, Classifications, and Environmental Impact of PCM-Incorporated Textiles: Current State and Future Outlook
Technical research
Phase Change Material (PCM) refers to a substance that changes state and provides latent heat while maintaining constant temperature. This process of changing physical properties is called a phase change, and during this process, the PCM absorbs or releases a significant amount of latent heat.
Heart Rate Monitoring: A photoplethysmography sensor (MAX30102) measures heart rate and oxygen saturation.
Muscle Fatigue Detection: A surface electromyography sensor (sEMG) measures the frequency and intensity of muscle contractions.
Exercise Intensity Tracking: An IMU sensor (accelerometer + gyroscope) tracks jump count and sprint intensity.
Prototype test
Heart rate module
IMU module
After the body touches the sensor, the recorded heart rate is displayed.
By shaking the IMU module at different speeds and angles, the screen will record and display different data.
sEMG module
The red part indicates the original electrical signal of the muscle.
The broken lines represent the electrical signals of muscle changes.
Coding
Future Improvements
Add a wireless communication module to enable short-range data transmission to the coaching staff at the sidelines, allowing real-time decision-making regarding player substitution and performance adjustments.
Add an advanced massage and compression module, comparable in performance to the system utilized in Strivonix’s compression recovery pants, to enhance muscle recovery and circulation efficiency.
Final outcome
