my point
EXACTLY!
If you can brace it against an overhang, you can brace it against your own foot; assuming you've got a good stance.
No. Not the same thing. Let apart the fact that its not mentioned in the text, it is a completely unsupported assumption. The counter forces provided from stable items or by the bow being anchored in the proper surface/material are much bigger than the ones you gain by bracing the bow against your own foot.
Moreover, the very fact that you use your own limb to do the job tells me that the body is not as free to get the maximum pull.
[MENTION=85123]kingius[/MENTION] A strong stance is much more resilient than ice or soil, especially a protruding overhang made of either.
Umm... No. A strong stance is a strong stance, a thing on its own. It is irrelevant to our debate
A simple long bow, a composite longbow, a Bone Bow... or whatever bow you like, they all need a "strong" stance... if by strong we mean a "proper" stance, cause I can't give any other meaning to "strong" as you put it.
Now the Bone Bow, in order to "work" needs to be anchored on one side, then the user can attain the "proper" stance and use it. Without the bow being anchored the user does not have the required strength to pull the string, and thus, cannot attain the proper stance.
From what I've seen, you hold a normal bow from the middle.
In the case of our Bone Bow (or any other anchored bow), I imagine that when the bow is anchored by the bottom spike, you hold it above the middle, and when the bow is anchored by the top spike, you hold it bellow the middle. That's the only way it makes sense to me anyway...
Half of the force is provided by the anchorment and half the force provided you hand, whilst when using a normal bow there is one force and it is provided by your hand only.
I'm sure someone can explain it better than me, but I think I'm close to the general idea of how it works.
Physically speaking, the spikes would be absolutely useless in a real-world scenario. Rooting one end of the bow will not help you pull the string, but it will affect the angles at which you can fire.
Imagine how useless a fixed position bow would be. Anyone with a shield would be immune to it, because the arrows are coming from a fixed angle. Anyone could crouch and the arrows would whiz over them. Anyone could move six inches left or right and be completely out of the path of the arrows. Small or smaller creatures could never be affected by it, and huge or larger would consider it a pin prick to the shin.
Perhaps, or perhaps the angles depend on the flexibility you give to the bow on each shot... or by something else...
STILL, that doesn't justify your assumption that you can use your boot instead.
[MENTION=85123]kingius[/MENTION] My argument is that any stability granted by putting a bone spike in a soft surface can be matched or exceeded by bracing that same spike firmly against a boot; not that resistance isn't a factor in maximum pull strength.
I think you are entirely missing the point here. You do not use the anchorment for stability purposes. You use it so as to profit from extra force.
Moreover no one spoke of "soft" surfaces as you put it. Personally I spoke of pierce-able materials/surfaces. Ice, for example is not "soft", but is pierce-able.