We are able to walk forward because

we are able to walk because of the forward and upward reaction force exerted by the earth on us.

when we walk, we push the earth backwards and downwards with our foot. We are able to do so because of the grip provided by the force of friction. The earth pushes us with an equal and opposite force as per third law of motion.Thus we are pushed by the earth in forward direction and we are able to walk.

wvbbvvv

a. spokes of a wheel.

as indicated in the question radial contains rad, also found in radius, so the fracture's would span the radius.