In footstep animation, the GravAccel (for gravitational acceleration) parameter lets you scale the height of airborne periods. The greater this value, the greater the height. If the biped appears to be going too high, reduce this value; if the biped goes too low, increase it. Each biped has its own Gravitational Acceleration value. The default is based on the height of the biped.
For example, if the active unit is feet and the biped is 5 feet 10 inches tall, then Gravitational Acceleration equals 32, for 32 ft. per second per second. For other biped heights, 3ds Max scales this value to fit the scene. The Gravitational Acceleration value also changes to agree with other unit systems, such as metric.
GravAccel is located on the Dynamics & Adaptation rollout.