Not to get too far 'out there', but there is some real science to the importance of being physically in touch with the planet. The earth has a resonant frequency (very low ~8 Hz) that apparently peaks around 8am and 5pm. This electromagnetic signal is critical to our circadian rhythm. It's called the Schumann Resonance and the space station has a resonator installed to duplicate it because without it, humans don't function properly (sleep disruption, unrest, depression, etc).

I would imagine that living in a concrete jungle surrounded by all manner of RF waves (from WiFi, cell phones, TV's etc) would greatly interfere with our bodies ability to pick up on the Schumann Resonance and might contribute to all kinds of disfunctions.

Anyway, it sounds hokey, but I feel peaceful when I get the chance to walk our property barefoot in the evening. I attribute it to getting in touch with the resonant frequency of the earth.