Introduction
Roundnet is a four-player ball sport where teams are composed of two players each positioned around a circular net. Similar to volleyball, once the ball is served to the opposing team, the two players on one team may touch the ball up to three times before having to hit the ball back onto the net, at which time it is conversely the other team’s turn to return the ball to the net. The team that fails to return the ball back onto the net within three touches loses the point, and games are played until one team reaches 21 points. Roundnet has recently gained popularity with over 4 million competitive and recreational players worldwide. People often play the game casually; however, competitive tournaments started in the past decade, and many players train and compete across a 6-month competitive season currently known as the Spikeball Tour Series as well as other emerging leagues and tournaments. The first four levels of play (beginner, intermediate, advanced and contender) are open to any athlete, while the fifth level (premier) and sixth (professional) levels of competition are earned through tournament performance during the season. In 2022, the first roundnet world championship was held in Belgium, with over 30 countries competing in men’s, women’s and mixed (men+women) divisions.
With roundnet becoming more popular and increasingly competitive, serving and hitting velocities may have increased. Many competitive players can serve with both hands (figure 1), while others serve unilaterally (similar to a sidearm baseball pitch) to increase serve velocity. Additionally, diving is very common in roundnet, whether to bump/set the ball or to hit the ball onto the net (figure 2). Diving may lead to acute injuries in many regions of the body in roundnet athletes.
While research on roundnet athletes is limited, the relationship between overhead workload and injury has been well established in other athletes such as baseball pitchers and volleyball players.1–4 Studies have found that pitchers who continue to throw while fatigued were at a 36× increased risk of injury, and similarly, the incidence of non-traumatic shoulder pain in volleyball athletes was significantly associated with the number of years played competitively.4 These findings describe how the chronic workloads experienced by overhead athletes contribute to injury. While the forces throughout the upper extremity are unclear in roundnet, these athletes experience high acute workloads as tournaments are very long (often >8 hours), and higher-level athletes may train often as well. The 6-month competitive season also suggests notably high chronic workloads in roundnet athletes. Because of this, roundnet athletes may be at risk for both acute and chronic injuries of the axial skeleton, upper extremity and lower extremity.
Despite the potential for both acute and overuse injuries, no study has described injuries in roundnet athletes or how they are clinically managed. Therefore, the primary purpose of this study was to describe injury frequency and characteristics in roundnet athletes and compare injury characteristics between elite and non-elite athletes. The authors hypothesised that elite roundnet athletes would report a higher rate of injuries compared with non-elite roundnet athletes.