Before revision: A (bipedal) gait cycle is the time period or sequence of events or movements during locomotion in which one foot contacts the ground to when that same foot again contacts the ground, and involves forward propulsion of the centre of gravity .
After revision: A (bipedal) gait cycle is the time period or sequence of events or movements during locomotion in which one foot contacts the ground to when that same foot again contacts the ground, and involves in the direction of motion propulsion of the centre of gravity .