 When only one foot is in contact with the ground ( known as single limb stance), the center of mass is in front of that foot and moving towards the leg that is in the swing phase.
<clarity>  When only one foot is in contact with the ground ( known as single limb stance), the center of mass is in front of that foot and moving towards the leg that is in the swing phase.
 When only one foot is in contact with the ground ( single limb stance), the center of mass is in front of that foot and moving towards the leg that is in the swing phase.