Yes -- one hand does the work and is more likely to come into contact with energized wires or rails. If the other hand is supporting your lean against the conduit or enclosure (grounded), the path is through your heart. We're conditioned to use both hands for everything, so it's extremely easy to "forget" or "cheat just for this step" and use the other hand to balance, or hold, etc. Having your hand firmly in your back pocket is unfamiliar enough that we remember, and far enough that a quick instinctive response is interrupted.
Wooden broom handle is a non-conducting lever that a helper can use to separate you from the energized equipment. The current can cause your hand muscles to spasm in a "gripped" position, so the broom handle might need to be applied with some force. This is a last-resort catastrophic situation response.
The way that electricity flows through a conductive medium, it doesn't matter if the circuit appears to "crosses your heart", because some portion of it will still flow through your heart regardless.
Or, to put another way, you'll still see current at the heart even if it only flows through two fingers on the same hand. And even if it's a really small portion of the current, it doesn't take much to stop a heart.
Plus, there are a virtually unlimited number of proven tools for seeing if the circuit is live (even if there's no current flowing) to rely on such dodgy methods.
Agreed that electrical potential is present in all points of a uniform conductor. And that it takes only a tiny amount of current to interrupt a beating heart (as low as 60mA).
However it is not correct that the path of the current is not important.
Current will not flow between two points of equal electrical potential. There are some complications in the modelling (skin is a better insulator than internal bits, bags of salty moist flesh and bones are not resistively consistent, etc), but you're still in a much better situation to reduce potential difference across your heart, if the external potential difference occurs between two fingers on the same hand, vs two fingers on opposite hands.
OSHA says:
> The currents that pass through the heart or nervous system are the
most dangerous. ... If a hand comes in contact with an electrical
component with current (and at the same time the other side of your body makes a
path to the ground), this will make the current pass through your chest and possibly
produce injuries to the heart and lungs.
The wording from the post that started this discussion is:
> Is "one hand in back pocket at all times" to avoid a circuit across your heart?
To which I responded:
> it doesn't matter if the circuit appears to "crosses your heart", because some portion of it will still flow through your heart regardless.
Which, as we have by now agreed, is the case.
The dispute is about whether that 'portion' is enough to kill you, which I avoided making concrete statements on. I didn't take a stance because the answer is "it depends". The variables that make up the answer are vast, and many folks have survived lightning strikes and died to static discharges thanks to those variables.
> being a bit smart about it
I will still contend that working on live wires with bare skin at all is the opposite of "being a bit smart about it".
If your really being smart about it, and can't avoid it, use tools and protective gear created explicitly for working with live electricity. Or call someone with that gear.
> Plus, there are a virtually unlimited number of proven tools for seeing if the circuit is live (even if there's no current flowing) to rely on such dodgy methods.
Yes. Use those. But this discussion is about when you are working on live wires, and you know you are working on live wires.
A homeowner will never have to do this. And an electrician has the ability to ensure they too don't have to ever work on live wires (despite many's insistence in doing so, something about machismo, etc.).
I have however had jobs where I really did have to work on energized equipment. Sometimes 480VAC 3-phase, but more commonly single-phase 230/240 VAC 50/60Hz or 120VAC 60Hz. I was appropriately trained for this work.
Some homeowners are too stubborn to do the proper thing when handling electrical equipment. You're not going to change their minds!
The precautions I mentioned previously were some of the more convenient and generally applicable rules that are taught to people who have to work with equipment that is less safe. If followed by stubborn homeowners, they will also be safer. That was my whole point.
