<span>The correct answer is "velocity, height". Kinetic energy is affected by: mass and velocity, while potential energy by: mass, gravity and height (or "position"). Considering these combinations, only the third choice is the correct one: a) position, gravity describe only potential energy, B) gravity, position describe only potential energy, C) velocity, height describe respectively kinetic and potential energy, D) height, velocity would respectively describe potential energy first and then kinetic energy, it is in the wrong order, thus the correct answer is C.</span>
If the center of the load is directly above the vertebrae, there is no torque in the system. This is a good thing so that the vertebrae are not put out of alignment over time. (Of course, this still doesn't prevent compression of the vertebrae over time, which is a possibility.)
