Disclosed is a prosthesis for a person with an amputation below the elbow to provide a replacement for at least a lower arm of the person. The prosthesis includes a receiving sleeve adapted to be attached to a stump of the person such that the stump can move the receiving sleeve. An electromechanical hand is attached to the receiving sleeve, the electromechanical hand having a rotary mechanism, a control unit, at least one finger and at least one motor. The rotary mechanism includes a potentiometer having a shaft in communication with the receiving sleeve such that a displacement of the receiving sleeve causes a corresponding rotation of the shaft of the potentiometer. The control unit is configured to measure the corresponding rotation of the shaft of the potentiometer and send a signal to the at least one motor to actuate the at least one finger.
