Couple of comment on what mmshiro said... Horses use their hinds differently and that is why theyre generally in healthier shape(which doesnt mean unhealthy fronts should be left shod), not that theyre less weighted, which isnt quite true anyway - depends what theyre doing as to how feet are weighted and hinds often cop more force.
She should NOT have 'soft parts'!! Her soles & frogs should not be soft & it indicates significant probs if they are. Theu will however likely be *thinner* than they should be, through lack of function & often farriers also pare sole & frog way too much.
And concavity for 'clearance' is not the issue
If the horse is living on yielding footing - regular paddock for eg - there isnt clearance anyway, regardless of concavity. And if a horse is working on hard ground then peripheral loading(be that shod or not) to the degree that frog & sole are suspended off the ground is NOT a good thing at all.
- Weight distribution, given that the horse "walks" most of its time, especially without rider: A GREEN HORSE is a NATURAL, ECONOMICAL and ECO-FRIENDLY WAY to a HEALTHY HORSE: Natural Horse Gaits
- If it doesn't sound like a piece of wood (or "hard" horn) when I tap on it, it's "soft". If pieces flake off from a structure that I can bend like rubber, that structure is "soft". In the hoof mapping video that's been offered as "excellent advice" around here, farrier states that a shod hoof often gets trimmed to the "waxy" part of the sole - which is probably "softer" than the "hard" hoof wall. My farrier states the same: A barefoot sole gets trimmed less than a shod one, so you get less close to where it gets "waxy". Because if you cut down to far, you don't have enough resistance against sharp objects like small rocks pushing through to where the real "soft" (living") tissue is.
- If the horse is on yielding footing, she probably won't have a problem with removing the shoes either way, just as you would not have problems barefoot in the pasture. However, the hoof wall, if extending a bit beyond the sole like a shoe would, will take some contact force off the center when riding on unyielding, abrasive surfaces like tarmac, or stepping on stuff that's the horse's equivalent of LEGO pieces. To take the metaphor back to you, even the "soft" rubber sole on your slippers gives a lot of protection here, followed by socks, followed by toughened skin, followed by barefoot with a princess's feet. (OP states she has to hit the road to get to the trails, the rockiness of which is unknown.) Naturally, all of the bottom of the foot will hit the surface she's walking on - I mean, that's the point of an elastic, shock absorbing hoof, the question is with what intensity while the foot builds up resistance. Key (the OTTB I'm leasing for the summer), I did not take out on the trails right after trimming until he had the chance to regrow some hoof wall. And yes, he was more ouchy in the beginning, when I just started taking him again, than we was today, for example.