An electronic device for percussive massage therapy. The device includes a reciprocating member configured to move at any number of different amplitudes and frequencies. In one example, the device is configured with a number of gears including a planetary gear, a ring gear, and a positioning gear, which permit amplitude to be varied between a great number of amplitudes within a predetermined range. The user may adjust frequency and amplitude of the reciprocating member in real time. In one example, the reciprocating member is adapted to vibrate to permit vibration therapy in addition to percussive therapy.