La technologie japonaise ne connaît pas de limites!

'Motorized Knee' Makes Running 30% More Efficient

TOKYO (Nikkei)--A research team at Tsukuba University has developed a motorized device that attaches to a runner's leg to assist with the flexing of the knee, allowing for less energy to be expended during jogging.


A subject runs with the assistance of the new device.
According to the team, people wearing the device only have to use 70% of the leg muscle power that is needed to run unassisted.

The group aims to develop commercial applications for the technology within three years, perhaps releasing a consumer product that can be used as readily as a bicycle.

The complete kit, which weighs about 5kg, consists of a motorized device that attaches to the thigh, and a control unit with a battery that is carried in a backpack.

The motor helps runners flex their knees as they stride, reducing the amount of effort expended by leg muscles. The system is designed to allow for smooth movement.


A sensor built into the motor anticipates when the foot comes into contact with the ground by measuring how far the knee is bent. Using this information, it optimizes motor movement.

In experiments conducted by the team, the device allowed subjects to jog at 7.5km per hour using as much as 30% less thigh power than normal. That speed is nearly twice the typical walking pace.

Similar devices already exist, but they are designed to help the physically handicapped walk, and as such are rather bulky. Since the new device is designed for healthy people -- namely, for them to run while using only the muscle power typically needed for walking -- the researchers were able to significantly reduce size.

The Tsukba team will partner with a yet-to-be-selected company to improve the device's safety and user-friendliness.

(The Nikkei Business Daily Dec. 16 edition)

• Motorized Knee Makes Running 30% More Efficient