An apparatus comprising: (a) a stationary base; (b) a drive assembly providing a drive member and means for reciprocating the drive member along a fixed linear path; (c) a femoral support extending between a first end connected to the base and a second end; (d) a tibial support extending between a first end connected to the second end of the femoral support and a second end; (e) a rigidly mounted, cantilevered femoral cradle slidably connected to the femoral support; (f) a rigidly mounted, cantilevered tibial cradle slidably connected to the tibial support; (g) a connecting member having an upper end connected to the tibial support second end and a lower end connected to the drive member; (h) a footrest structure mounted forwardly of the tibial cradle; and (i) the above elements arranged such that a person's leg is cyclically flexed and extended in response to reciprocation of said drive member.