In order not to jounce the patient in carrying him the bearers should break step.
It simply, said, "Processions in crossing this bridge must break step."
Now, in the crossing of bridges, moving bodies of men must break step or even well-built structures might be threatened.
The mahouts were hurried down into the hold, and each, seated on his beast, made him "break step" so to speak.
Old English steppan (Anglian), stæppan (West Saxon) "take a step," from West Germanic *stap- "tread" (cf. Old Frisian, Middle Dutch, Dutch stap, Old High German stapfo, German stapfe "footstep"), from PIE root *stebh- "to tread, step" (cf. Old Church Slavonic stopa "step, pace," stepeni "step, degree"). Originally strong (past tense stop, past participle bestapen); weak forms emerged 13c., universal from 16c. Stepping stone first recorded early 14c.; in the figurative sense 1650s. Step on it "hurry up" is 1923, from notion of gas pedal; step out (v.) is from 1907.
Old English steppa (Mercian), stæpe, stepe (West Saxon) "stair, act of stepping," from the source of step (v.). Meaning "action which leads toward a result" is recorded from 1540s. Warning phrase watch your step is attested from 1934. Step-dancing first recorded 1886.