You all missed the real reason. Holding the hands behind the back allows walking and standing with a slight hunch forward. This relieves the nerve compression of sciatica, a common ailment of older people, especially men. It is possible that many who do this don't even fully recognize why they do it, but just that it makes them feel better.
FLASH Application. Online Application for an Insurance License. The California Department of Insurance (CDI) requires California resident applicants to first pass the qualifying license examination prior to submitting their license application.
What is Arc Flash? Arc Flash is the result of a rapid release of energy due to an arcing fault between a phase bus bar and another phase bus bar, neutral or a ground. During an arc fault the air is the conductor. Arc faults are generally limited to systems where the bus voltage is in excess of 120 volts.