Spinal kinematics of the living human volunteers undergoing -Gx impact acceleration are described along with the experimental procedures followed to acquire such data. There were 4 male and 3 female volunteers who were subjected to impacts in the tensed and relaxed mode from 2 - 8 g, in 1-g increments. Their lower extremities were tightly clamped to the impact seat and the pelvis was restrained by a lapbelt. The biodynamic response of the living spine is quite similar to that of the cadaveric spine, particularly in terms of T1 displacement, acceleration at T1 and flexural resistance. Female volunteers tend to withdraw from the test program at lower g-levels than males due to transient neck pain.