Engineers at Oregon State University, Corvallis, have developed an implantable device using a simple pulley mechanism to improve hand function after surgery. They say that this is one of the first instruments ever created that could improve the transmission of mechanical forces and movement while implanted inside the body.

The new mechanism is a passive technology using a basic pulley that can be implanted within a person’s hand to allow more natural grasping function with less use of muscle energy, following traumatic injury, stroke, paralysis, or other disorders.

They say that the mechanism developed for this problem can produce more natural and adaptive flexion of the fingers in grasping. The needed force to close all four fingers around an object was reduced by 45 percent, and the grasp improvement on an object reduced slippage by 52 percent.

Further research may offer new options to people who have lost the use of their hands due to nerve trauma, and ultimately be expanded to improve function of a wide range of damaged joints in the human body, the scientists report.