'Give us a leg up '

This stone is right next to the bus stop in my village,though I presume that the stone was there first haha
Most locals think its a stone for helping you to mount a horse,and there is part of the stone carved out at the backto get a foot hold but I wonder what the significance of the 'Arrowhead 'shape on the top?? If anyone knows about these stones please let me know.
Changing the subject completely I have finished painting the offices in Norwich,and Im delighted, and also Knackered I doubt I will take on such a big job again.
Tomorrow I am over the road at G and P's to decorate there hall stairs and landing,so with luck will be finished by teatime !!!
Im sorry to have been such a bad blipper of late,and not commenting but I really have been so busy but will be 'back to normal' soon I hope