Final answer:
You cannot touch your toes while standing with your back to a wall because your center of gravity moves outside of your support base when you lean forward, causing you to lose balance. Women may find it slightly easier to perform this task due to their lower center of gravity.
Step-by-step explanation:
You cannot stand with your heels and back to a wall and bend over to touch your toes and return to your stand-up position because doing so defies the principles of center of gravity, support base, and torque. When you stand upright, your center of gravity is above your feet which constitute your support base. This configuration ensures you are in stable equilibrium, much like a pencil balanced on its eraser.
While bending forward, to maintain balance, your center of gravity must stay above your base of support otherwise you will topple. Since your feet are not far apart and the wall prevents you from moving your hips back, your center of gravity moves outside your support base once you bend forward, causing a torque that tips you forward. This situation can be averted by either having a wider base of support or by positioning the center of gravity within the base of support, which is not possible when constrained by the wall.
It is generally easier for a woman to do this exercise due to a typically lower center of gravity, which means their bodies are more stable to begin with and can maintain balance better in challenging positions.