“Muscle memory” is the process in which a certain motor task is repeated to such an extent that it can eventually be performed without conscious effort. It comes in handy for all sorts of activities, but is particularly important to athletes – a tennis player can hardly concentrate on the game, for instance, if they’re constantly thinking about how to move their arm every time they return the ball. Now, engineers from Imperial College London have created an armband device known as Ghost, designed to assist athletes in forming optimum muscle memories.

The armband (or separate wrist and elbow bands, really) contains sensors that detect the flexing and twisting of the wearer’s joints, along with vibrating pads and LEDs located at each joint.

In a typical scenario, a coach might start by using a hands-on approach to guide a tennis player through a perfect swing, setting a number of way-points on the Ghost while doing so. When the athlete then went to practice that swing on their own, the sensors would cause selected pads and LEDs to activate, in order to once again guide the wearer through the correct movement. After enough repetitions, their arm would end up “learning” the swing, and the Ghost would no longer be needed.

The device could also conceivably be worn by top-level athletes, and used to record their signature movements. Amateur athletes could then put on a Ghost of their own, which was loaded with a file of the pro’s moves, so they could learn those actions for themselves. An amateur golfer, for instance, could train with a Ghost that was “playing back” a file of Tiger Woods’ swing.

Originally, the technology was developed for use by blind swimmers. Not only can they not observe other swimmers who are “doing it right,” but like anyone, they also can’t hear a coach’s verbal feedback when their ears are underwater.

Ghost utilizes an Arduino microprocessor along with other off-the-shelf components, and is currently still in the prototype phase. There is no word on whether other models are being developed for other body parts.

It’s somewhat similar to Move, an experimental tank top-like garment that guides its wearer through the proper movements for activities such as yoga and Pilates.