Researchers at the Imperial College London have developed a sensor worn behind the ear that can measure an individual's biomechanical data, such as his or her posture and gait, during an activity. The data is then wirelessly transmitted to a computer so that the wearer's performance can be measured and assessed in real time.

The sensor could be used to both optimize athletic performance and help monitor changes in movement in people recovering from surgery or suffering from neurodegenerative diseases. According to Guang-Zhong Yang, a professor in the department of computing at Imperial College and the project leader, the device works and could be mass-produced within 12 to 18 months.

There are a number of technologies that are looking toward providing this kind of information about an athlete's performance, says Peter Vint, a senior sports technologist for the United States Olympic Committee. "But what distinguishes it [the sensor] from others is it is very small and worn on a place in the body that is stable in noncontact sports."

The sensor is about the size of a cuff link and measures the posture, stride length, step frequency, and acceleration of an individual. In addition to being used in applications for training athletes, the device could be employed to monitor a patient's recovery after surgery, such as orthopedic, or injury, such as a fracture. In those cases, an individual will often compensate for the affected area, which impinges movements, says Yang. The device could also be used to monitor an individual suffering from a progressive illness, such as a neurodegenerative disease: it could detect telltale changes in the person's movements.

The sensor uses an accelerometer that allows it to measure motion in three dimensions. For example, when a runner hits the ground, a shock wave is transmitted through his body from his foot. The accelerometer is able to pick up these waves and sense the balance of the body and the changes in the runner's gait, such as the length of strides and the frequency of steps.

This information is processed within the sensor and wirelessly transmitted to a computer, where software developed by Yang's team automatically extracts the data, analyzes it, and displays the results.

Being able to look at the data in real time is a big advantage because a viewer could see a runner's stride length start to shorten and know that she is going to have problems finishing the race, says Scott McLean, an associate professor of kinesiology at Southwestern University.

The device has been tested on individuals recovering from surgery and is currently being tested on athletes. The researchers hope to improve the range of the sensor, which is currently only at 10 meters, and incorporate more information, such as heart rate, says Yang.