Green’s Dictionary of Slang

a method of carrying a drunken or recalcitrant person, whereby one holder each takes a limb and thus suspends the individual in mid-air.

1871		Eve. Standard, Clerkenwell Police Report 18 Apr. n.p.: In cross-examination the police stated that they did not give the defendant the frog’s march. The frog’s march was described to be carrying the face downwards [F&H].
1884		Daily News 4 Oct. 5/2: They had to resort to a mode of carrying him, familiarly known in the force, we believe, as the frog trot, or sometimes as the frogs march The prisoner is carried with his face downwards and his arms drawn behind him [F&H].
1890		Bird o’ Freedom 19 Mar. 1/1: And then he gets the frog-march to the nearest Tealeafs [F&H].
1992		Bentley & Corbett Prison Sl. 10: Frog’s march is a method prison guards use to carry and transfer difficult, hard-to-handle inmates. This method consists of four officers each grabbing an arm or a leg and carrying the inmate, face down, parallel with the ground.