Researchers at the Imperial College in London have developed a device which can be worn behind the ear and is used to measure a subject's posture, stride length, step frequency, and acceleration. Apparently, such a sensor is in high demand, as it could be put to use helping to optimize athletic performance, and to monitor changes in movement or progress in people recovering from surgeries or those suffering from neurodegenerative diseases. According to the project leader, Guang-Zhong Yang, the device is working and could be mass-produced in 12 to 18 months. Of course, the big selling point for the sensor is the fact that it's small enough to be worn on the body -- even during non-contact sports -- and is capable of measuring three dimensions of movement via its accelerometer. Researchers are testing the sensors on individuals recovering from surgery and athletes, with aims to broaden the types of data recorded, and improve the range of the device.