An abductory twist is a sudden and abrupt abduction of the rearfoot just as the heel is coming off the ground during gait. The abductory twist on its own is not necessary a problem and it really just a sign of an underlying problem that may or may not need to be treated or fixed.
As explained here there are two possible causes of an abductory twist. One is a functional hallux limitus and the rearfoot abducts when the heel comes of the ground to get around the block at the first metatarsophalangeal joint. The other is an “overpronated” foot in which the foot is everting at a time when the leg wants to be externally rotating, so as the friction from the ground stops just as the heel comes of the ground, the foot will suddenly abduct due to that stored external rotation from the leg. It is not clear which one of these is the actual main cause of an abductory twist or if another cause is involved. The abductory twist should not be confused with the medial heel whip which occurs later in the gait cycle and may be due to more proximal issues.
To fix an abductory twist, you need to fix either the functional hallux limitus or the “overpronation”. There are no exercises that can be done to help this as they are mostly due to structural issues in the foot. Sometimes the “overpronation” can be due to functional proximal problems that exercises can be used for to help, but this is not a common cause.
Podiatry Arena has a number of threads on the abductory twist that may be worth pursuing to get a deeper understanding in addition to the resources linked to above.