“Notch” motion tracker can map exactly how your body moves

Fitness trackers like Fitbit and Fuelband are great at logging how much your body moves over a given day, but if you want more detail, like the angle of your knee or the jut of your hip, you’re going to need more than just one sensor. That’s where Notch comes in. The new system takes a modular approach to motion tracking. Each sensor collects accelerometer data, with up to 10 sensors funneling it all back to the user’s phone at any given time. It’s enough data to allow for skeletal tracking and much deeper analysis of how you’re body’s moving. For walking, that’s simple enough — but for more complex movements like a tennis serve or a karate kick, the device offers a data-driven window into the mechanics of the body that most people have never even considered.