Question

which of the following is a component of the proper technique for lifting heavy materials?
hold the materials away from the body
bend the knees
raise the materials to shoulder height
bend at the waist

Explanation:

When lifting heavy materials, bending the knees helps keep the back straight and reduces strain on the lower back. Holding materials away from the body increases torque on the back. Raising materials to shoulder height can be strenuous. Bending at the waist puts excessive stress on the spine.

Answer:

bend the knees