Sensation in hands - has anyone else experienced this?

I've been running barefoot for about three months now and every week I do a kilometre or so along a very rough patch of pathway to condition my soles. For a day or so afterwards, I experience a (not unpleasant) sensation in the midpalmar space of my hands (see pic). It's not pain, per se, but rather like the feeling you get in your shoulders when you're tense. This responds well to a bit of a rub. I just wondered if anyone else had experienced this.
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