Abstract: An infant environmental transition system provides an infant with controlled simulated movements encountered by an infant in an intrauterine environment. The system includes a suspension system having a plurality of flexures coupled between a base plate and a moving mattress platform. A cam shaft assembly includes a groove that engages a linear follower connected to the moving platform so that the follower moves along the groove while the cam shaft assembly rotates to move the linear follower, and thereby reciprocate the moving mattress platform in a longitudinal direction. Alternatively, a rotating crank assembly translates crank rotation to reciprocating movement of the mattress platform.