What are the three main forces that affect the spine when lifting? Select all that apply. Options: Tension, Compression, Shear, Torque

Answer

When lifting, the three primary biomechanical forces acting on the spine are compression, shear, and tension. Compression refers to the downward axial load placed on the spinal discs and vertebrae due to body weight, gravity, and the load being lifted combined with muscle contraction. Shear forces act parallel to the surface of the vertebrae, tending to slide them horizontally over one another, which commonly happens when lifting improperly with a rounded back. Tension (or tensile force) occurs on the posterior side of the spine as back muscles and ligaments stretch to resist the forward bending moment. Therefore, the correct options to select are Tension, Compression, and Shear.