The retention of balance: an exploratory study into the limits of acceleration the human body can withstand without losing equilibrium.

The human limiting values for sudden accelerations we have determined can be used to evaluate specific physical conditions that cause problems in maintaining postural balance. A comparison between the data obtained in the laboratory and the situations occurring during public transport by tram, bus, and metro revealed that both the initial impetus ("jerk") and the level of acceleration found in practice were sufficient to ensure that none of the individuals measured in the laboratory would have been able to retain their balance without extra support. The study suggests that limiting the initial jerk component of the acceleration would help considerably in alleviating the problem.