Falling off a chair, how best to save yourself

Question

If I consider a man sitting on an office chair that reclines backwards iff you lean backwards.

What could be done to prevent hin from falling? a) raising his legs till they are parallel to ground. b) bring the feet closer to himself(as close as possible) and press them down on the ground.

Please don't suggest any other way. I want to compare these two. Ie, which is better.

Argument in favor of a)

The center of mass moves away from the rear end of the chair towards the forward end of the chair so torque of weight will restore the chair. (This works if you are in an armchair, and are rocking to and fro). However, intuition says contrary to this. I feel scared of falling If I do this.

Argument in favour of b)

Intuition favours this. Normally when we talk about balancing our body, what "feels right" is better for the safety. So, I can not say what is right. Please explain what your views are in this case. Again, the purpose of this question is not to ask what should be done, only what is better to do out of these two choices.

Answer 1

This sounds to me like an experimental question (but be careful not to hurt yourself!).

Note that since you want the chair to rotate forwards towards the ground, you'll want to consider the direction of the angular momentum your motion introduces. If you kick your legs out rapidly, not only does the weight of your feet tilt the chair forward, but the angular momentum of your legs moving upwards in front of the chair will tend to be balanced by an upward motion of the back of the chair. However, if you're tilted too far backwards before you kick out your legs, you'll get a second and opposite angular momentum kick once your knees are straight, which might send you over backwards.

This is why the best approach is to stick out your legs and pinwheel your arms.