Final answer:
The limiting factor for the amount of weight that can be lifted throughout the full range of motion is the strength of our spines. Proper lifting technique with an erect back and engaged legs helps minimize the forces on the back.
Step-by-step explanation:
The limiting factor for the amount of weight that can be lifted throughout the full range of motion (ROM) is the strength of our spines. Although similar forces are created in our hips, knees, and ankles, our spines are relatively weak. Proper lifting technique, which involves keeping the back erect and using the legs to raise the body and load, helps to minimize the forces on the back.
For example, if a person lifts a weight while standing erect, the forces on the back would be about 5.6 times smaller compared to lifting the weight with a bent back. This is because proper lifting distributes the forces more evenly across the body and reduces the strain on the spine.