"Every place whereon the soles of your feet shall tread shall be yours: from the wilderness and Lebanon, from the river, the river Euphrates, even unto the uttermost sea shall your coast be." (Deuteronomy 11:24)
So, rewinding back to our Indo-European roots for this one, plantigrade comes to us from the roots "ghredh" and "plat-". The former meaning "to walk" and the latter "to spread". The word itself carries the definition of "walking on the soles of our feet". Humans do it, bears too. And all I really have to add by way of allusion and metaphor is that of distance. I'm reminded of the time when "Jesus", it says, "[was] led up of the Spirit to be tempted of the devil." (Matthew 4:1)
Covering ground
I walk a lot. I have a sort-of nervous energy through which walking is the perfect outlet. I can't stand to be sitting still unless I'm writing or else wound down at the end of my day. Chalk it up to the fact that I've worked the same job for most of my life (bookseller) and the idea of going from work, to the breakroom, stanching the flow and output of my energies is not a pleasant one. And so, I cover ground. The fifteen minutes I'm allotted is just enough to make it around the block and back. I love it. Rain, snow (not much of that where I live), heat, cold. No matter. The locale feels pretty much like a wilderness (maybe it's just me) and so I walk. The focus—it's the same reason I run—and the clarity. Walking does this. It's something, I suppose I can say this in light of any and every worldview, that we were designed to do. It feels natural. For a moment, at least, your entirety is balanced on the ball of your foot and you press on. One foot in front of the other until you reach your destination. Walking is walking. Simple. Primal. Fluid. The perfect machine that is our body can get where it needs to go through the simplest of processes. On your feet! There's ground to cover.
"For the land, whither thou goest in to possess it, is not as the land of Egypt, from whence ye came out, where thou sowedst thy seed, and wateredst it with thy foot, as a garden of herbs: But the land, whither ye go to possess it, is a land of hills and valleys, and drinketh water of the rain of heaven: A land which the Lord thy God careth for: the eyes of the Lord thy God are always upon it, from the beginning of the year even unto the end of the year." (Deuteronomy 11:10-12)