Question

Why can't you stand with your heels and back to a wall and then bend over to touch your toes and return to your stand-up position?

Answer 1

Answer:

Due to the rotating effect created due to opposite acting offset forces of the body weight and the normal reaction from the heels.

Explanation:

• We cannot stand on heels with a wall at the back support and then bend over to touch the toes and regain the position back by standing up because we have the center of mass of our body somewhere at the abdominal portion of our body.
• So, while standing on our heels we are giving our body only one point to support and balance itself.
• On bending the center of mass of our body shifts forward and it is now not vertically in line to the direction of the support reaction from the heels because of the wall at the back we cannot bend our knees and move our weight over our heels for gaining the balance. Due to a difference between the these two opposite forces we have a turning effect called moment on the center of mass of our body. This tries to rotate our body in the forward direction about the center of mass of our body.

Answer 2

Explanation:

We cannot stand with our heels and back to a wall and then bend over to touch your toes and return to our stand-up position because,

Our centre of gravity above our base of support is too high. A vertical line through our body's center of gravity extends behind our feet, beyond our base of support.