In walking during stance phase I stabilize on one leg so that the other leg can move through swing phase. It is not that all of the muscle groups in stance are fully contracted but if some are not fixed the gait is impaired. One muscle group is the hip abductors. If one side abductors do not contract one gets a fall of the pelvis on the opposing side. Trendelenburg gait pattern.
During the stance phase, the weakened abductor muscles allow the pelvis to tilt down on the opposite side. To compensate, the trunk lurches to the weakened side to attempt to maintain a level pelvis throughout the gait cycle.
In order to be able to clear the leg during swing on the strong side excessive movement has to be made to the weakened side in the trendelenburg gait. During normal gait I fix one set of hip abductors so the other leg can move.
If I am kicking a soccer ball ball I do not usuallly pay attention to the stance leg fixed muscualture but I am focused on the contact with the swing foot. I position my body to get the best contact with the foot hitting the ball. I feel something similar is going on in my tongues. I fix my left tongue/jaw/throat so my right tongue/etc has a better chance of sounding right. In order for me to talk my left tongue/etc knows it's job is to contract and to put the right in a better position. My left tongue plays a more subordinate fixed role for my right tongue.