Muscle groups modulating mediolateral ground reaction forces to transfer weight from the right leg to the left leg during double support. (A) The abductors on the right leg act with the hamstrings, vasti, adductors, and gluteus maximus on the left leg to generate leftward ground reaction forces. (B) The plantarflexors and adductors on the right leg, along with the abductors on the left leg, generate rightward ground reaction forces.