 Ride designers must carefully analyze the movement a ride subjects its riders to, ensuring its within a reasonable tolerance.The human body needs sufficient time to react to sudden changes in force in order to control muscle tension and avoid harmful consequences such as whiplash.Designers typically try to stay in the range of 4–6Gs (40–60 m s−2) as a maximum for positive g-force acceleration, which increases the feeling of weight and pushes riders downward into their seat.