Youve heard of car airbags deploying within milliseconds to protect passengers. How about an airbag for your knee? Thats what former basketball hopeful Kylin Shaw is working on with his startup, Hippos Exoskeleton a knee sleeve that measures stress on the knee joint and inflates around the knee to protect it from major injuries like ACL and MCL tears. The sleeve inflates in 30 milliseconds, which the company says is faster than the 60 milliseconds it takes for ACL tears to occur. I, myself, have loved basketball since I was six years old, and for the next decade, it became my entire life, Shaw told TechCrunch.I dedicated myself to intensive training But at 17, just as I was preparing for a professional basketball career and NCAA trials, I heard a sickening pop from my knee while landing from a dunk, he said.The injury ended Shaws sporting career prospects, but it gave him the idea to combine AI-driven sensors and a knee-bag. He dropped out of the London School of Economics to develop it.Hippos said the brace uses predictive AI to detect risky movements in real-time and deploys airbags around the knee, potentially saving athletes thousands in medical expenses.Shaw and his co-founder Bhavy Metakar (CTO) initially bootstrapped Hippos by investing $1,000 of their savings to develop a prototype and generate initial pre-orders from clinics and athletes. The startup has now raised a $642,000 pre-seed round from investors Possible Ventures and Silicon Roundabout Ventures.Shaw told Techcrunch the company has already secured over six figures in pre-orders, and would use the new funding to develop the product further and push to a full launch in around three months.He said the eventual unit would cost around $129 and come with a $29/month to $99/month subscription plan covering AI-driven insights, small air canisters, and workout tracking.The startup has performed trials with U.K. football clubs as well as with star athletes, like world skiing champion Alex Schlopy of the U.S. Ski Team. In a statement, Schlopy said: Im impressed by the preventative function and it feels so light and comfortable! This brace gives me a sense of psychological safety.Beyond elite athletes, Shaw said the product could be used for injury prevention for anyone else, such as those in construction jobs or the elderly.Hippos may well be pushing at an open door. While approximately 150,000 ACL injuries are reported in the United States each year, and 8.6 million globally among adults, those stats dont include injuries among children. Also, most health solutions focus on rehabilitation rather than prevention. Moreover, existing companies addressing joint protection in sports and rehabilitation focus on traditional supportive devices or post-injury support.Brands in this space include Enovis DonJoy (orthopedic braces and supports), ExoKinetics Zeen (devices primarily for rehabilitation), and Shock Doctor (sports braces and protective gear for injury management). None of these solutions offer predictive or reactive technology in the way the Hippos air-bag does.Also participating in the round were Huggingfaces co-founder and CSO, Thomas Wolf; Wayves co-founder Amar Shah, and Dr. James Brown, the lead sports medicine doctor at UK Athletics.