“…Notable among these have been reports relating to the effects of immobilization by way of a plaster cast (Dietrick et al. 1948), studies of bedrest (Birkhead et al, 1963;Miller et al, 1964aMiller et al, , 1964b, the effects of confinement in special rooms (Alluisi et al, 1963;Hanna et al, 1963;Lebedinsky et al, 1964). Perhaps more closely related to space missions have been studies of submarine confinement (Fawcett and Newman, 1953;Weybrew, 1963) and in space-cabin simulators (Celentano et al, 1963;Lawton et al, 1964;Grodsky and Bryant, 1962;Hanna, 1962;.…”