Question

Explain one of the reasons why pregnant women often suffer from back strain late in their pregnancy.

Short answer

The pregnant women suffer from back pain as the back muscles need to provide more force to balance the torque of equilibrium.

Step-by-step solution

Torque

Torque is just a force's inclination to turn or twist. Torque is described using a variety of terminology, including moment and moment of force.

The point of Equilibrium

The equilibrium of an object is created when the center of gravity lies near the ground. On average, the normal human body has the center of gravity near the navel. The point lies in a line between the feet.

The Reason of Strain

The abdomen becomes heavier, and the center of gravity shifts forward in the case of a pregnant woman. As the center of gravity shifts forward, the pregnant woman experiences a clockwise torque about the upper body pivot and can topple forward.

Therefore, the back muscles need to exert an anticlockwise torque to maintain the equilibrium. As the back muscles are very close to the pivot, the force must be significant. This large force causes back pain during the later months of pregnancy.