Which of the following factors isn't part of the lifting equation and therefore doesn't contribute to the possible strain caused by lifting?

Answer

The correct answer is 'The strength of the lifting person'. In ergonomics and biomechanics, standard lifting equations (such as the NIOSH lifting equation) focus on external physical factors of the lift—such as the weight of the load, vertical height of the hands from the ground, and horizontal distance of the hands from the body—to calculate physical strain and risk of injury. The internal physical strength of the individual performing the lift does not change the mechanical load or physical strain imposed by the object/person being lifted, meaning it is not a variable included in calculating the physical strain in the lifting equation.