Next11: Sensors tackle football's injury problem

The numbers are alarming: football injuries are increasing dramatically, and costs are exploding. The latest study by British insurance company Howden on Europe's top-5 leagues (Germany, England, Spain, Italy, France) shows more than 22,000 injuries with over one day of absence in the past five years. "Thigh injuries in particular have increased by 100 percent over the past 20 years," says Nikolaj Thomassen, founder of Danish startup Next11. "And with severe ACL tears, a huge problem in professional womens and mens football, 50 percent of all players never return to the field." 

To prevent injuries, coaches rely on tracking systems designed to monitor the strain on players. However, according to Thomassen, all established solutions have a fundamental problem: they measure in the wrong place. GPS systems, local positioning systems and optical tracking devices record movements in the upper body – not where the injuries occur. "You wouldn't measure the strain on a horse's legs with sensors on the jockey's back," Thomassen sums it up. 

The problem with existing systems also lies in the 20-year-old GPS technology, which was originally developed for cars, boats and aeroplanes – not for explosive football movements. "These systems are based on the false assumption that running faster automatically means more strain on the legs," says the Next11 CEO. "Anyone who has ever played squash knows that you don't have to run far to be completely exhausted."

That is why Next11 has developed a solution with small sensors weighing only 20 grams that are inserted directly into the players' socks. With 50 measurements per second, accelerometers record all movements in three dimensions – 270,000 data points per 90-minute game and player. The measurements are transmitted live to a base station via Bluetooth. Even in large stadiums with 40,000 spectators, this works smoothly – as proven at European Championship matches played by the Danish women's national team, says Thomassen. The base station sends the compressed data to the cloud via LTE over the global Telekom network. 

The Next11 cloud uses machine learning to compare each footballer with themselves, i.e. with their performance in previous matches and training sessions. Coaches can see in real time when a player has reached their capacity limit. "If they have already reached their maximum capacity after 65 minutes, there are still 25 dangerous minutes left in the game during which their legs will tire," warns Thomassen.

In addition, Next11 developed a smart ball in cooperation with the manufacturer Derbystar. Sensors in the ball detect who shoots how hard and measure passes, ball possession and passing accuracy. This also allows conclusions to be drawn about the strain on the legs of individual players. 

The partnership with Telekom, which began in 2023, proved to be business-critical. "The integration of Telekom connectivity has transformed our system from a beta version to a commercially competitive product," says Thomassen. The coaching staff now receives player information live on their tablets. Before LTE integration, updates for the system also had to be manually transferred to the base station via cable – a cumbersome process. Over-the-air updates via LTE now run automatically in the background.  

The global Telekom SIM works reliably and securely worldwide without geographical restrictions. "We really appreciate that we don't have to negotiate with local providers first when expanding into new countries such as Malaysia," says Thorbjörn Mumme, Senior Engineer at Next11.  

Around 30 teams are already using the Next11 system internationally, including the Danish women's national team, 1. FFC Turbine Potsdam, the Paris St. Germain youth academy and teams in Portugal, Norway and the USA. The system works indoors and outdoors and is also used in handball and ice hockey. Next11 is aimed specifically at youth clubs and women's clubs for whom the systems previously available, costing up to £20,000, are unaffordable. "We have made it our mission to develop a tracking system that everyone can afford," says Mumme. The initial focus on women's teams was strategic: women's football has long been underfunded and was therefore more open to new technologies. "Incidentally, women are particularly affected by cruciate ligament tears," says Thomassen. "They have a tenfold higher risk, particularly due to hormonal influences that lead to softer ligaments and faster muscle fatigue." 

The Danes are currently in a financing round for their US expansion. The American market is particularly attractive: strong college sports, growing youth academies and professional leagues. "In the US, women's football is also more popular than men's football," says founder Thomassen. In addition, the Men's World Cup in the US, Mexico and Canada is just around the corner. The Telekom partnership strengthens investor confidence by demonstrating the international scalability of the product. "A local provider would not have the same persuasive power," says Thomassen.

The goal remains ambitious: to convince as many clubs as possible that their current data is insufficient and that they are exposing their players to injury risk due to a lack of load management. With Telekom as a global partner and growing evidence of the superiority of leg tracking, Next11 aims to help stem the tide of injuries in football.