Apparently mainly air pressure: > The pressure wave created by an arc flash explosion has the force of thousands of pounds per square inch. This is powerful en

Apparently mainly air pressure: > The pressure wave created by an arc flash explosion has the force of thousands of pounds per square inch. This is powerful enough to knock down or throw nearby workers and at the same time cause damage to the eardrums, lungs, brain and other vital organs. https://www.electricityforum.com/iep/arc-flash/electrical-arc-blast https://www.electricityforum.com/iep/arc-flash/electrical-ar... (I didn't know that, and just found that explanation while looking for an answer to your question.) A different risk is that electric current passing through the body could cause muscle convulsions, which could also cause someone to move or fall suddenly or erratically.