Originally Posted by aspin231
... would you use corrective trimming to 'straighten them out'? Meaning, rasp the inside wall down further than the outside wall to make their legs appear straight until the hoof grows out again?
Would that 'torque' the leg too much, or is it of benefit?
The image presents an example of a conformational defect called fetlock valgus. "Corrective" trimming is contra-indicated in these cases and, as you have suggested, will create rotational torque.
The carpal, fetlock, pastern and coffin joints (common names) are all ginglymus or "hinge" joints. They are designed to permit motion only in the dorsal/palmar plane.
While there is some medial/lateral "play" in these joints, intentionally creating imbalance in the supportive distal surface of the adult hoof will have a cumulative deleterious effect on the joints of the distal limb.
All that said, the distal limb joints of a foal may allow for some correction in the first few months of life, before ossification of the epiphyseal plates occurs.
In summary, it is generally incorrect to intentionally create medial/lateral imbalance in the hoof.