Leaning the trunk toward the side of the affected muscles inclines the ground reaction force laterally from its point of application at the foot. Because the vector then passes closer to the hip joint's antero-posterior (AP) axis, its moment arm is shorter, and it produces a smaller hip adductor moment.
THIS GAIT DEVIATION IS ALSO CALLED A GLUTEUS MEDIUS LIMP, SINCE IT CAN SIGNIFY WEAKNESS IN THAT MUSCLE GROUP.
