This study investigated in 15 young adults whether their walking pattern was altered after forewarning for a possible trip. Such changes might affect tripping reactions and consequently the validity of experimental results. Kinematics and dynamics were measured during overground walking. No changes occurred in walking velocity, step frequency, duration of stride cycle, stance, swing and double support time, or step length. A small increase was found in step width and foot clearance due to ankle dorsiflexion, but these changes were not expected to alter the probability of tripping nor the recovery reactions after tripping in an experimental setup. © 2001 Elsevier Science B.V.