Which lifting technique reduces back strain when moving heavy objects?

• A. Keep back straight and hold object close
• B. Twist at the torso
• C. Bend at the waist
• D. Bend at the knees when lifting heavy objects

Answer: (D)

Using the legs to lift reduces back strain by transferring the load to the strong muscles of the thighs and hips while keeping the spine in a neutral position. When you bend at the knees, you lower your body and maintain a straight, aligned spine, so the back isn’t bearing the initial bending moment. This way the quadriceps, hamstrings, and glutes do the heavy work, which is safer for lifting a heavy object. Keeping the object close to your body further reduces the lever arm, meaning less torque is applied to the lower back. In contrast, bending at the waist or twisting at the torso increases bending and shear forces on the lumbar spine, raising the risk of injury. So bending at the knees engages the right muscle groups and protects the spine during a heavy lift.