Final answer:
The vertebral motion segment is more resistant to compression, distraction, and bending but is less resistant to shear forces.
Step-by-step explanation:
The vertebral motion segment is far more resistant to compression, distraction, and bending than it is to shear forces. The structure of the vertebral motion segment, which includes symphysis joints formed by intervertebral discs and synovial joints between adjacent vertebrae, is designed to handle various types of mechanical stress. However, the spinal column faces challenges with shear forces due to the angular forces exerted when the normal curvature of the spine is increased. This increase in curvature, for example in individuals who are overweight or pregnant, moves the center of gravity backward to maintain balance, which in turn heightens the shearing stress on the spine, especially on the lumbosacral disc. Increased shearing forces can result in a higher risk of back injury, including ruptured discs.