Part one of this series discussed using touch on yoga students to help them get into a more accurate expression of a pose. A corollary to that is moving a student out of a potentially harmful position.
A recent example I saw in a class was a Warrior I pose. The back leg and ankle of the guy in front of me were collapsing toward the ground. Rather than having his weight to the outside of his rear foot, he was pressing down onto his inner arch. Putting too much pressure on the inside of the leg in this position could seriously hurt his knee and ankle. A proper adjustment might be to approach him from the rearward and wrap your fingers around his knee, then gently lift the pressure off the collapsing joint. At the same time, verbally cue him to back slightly out of the pose and shift his weight to the outside of his rear foot. Injury avoided.
Chaturanga also offers a unique opportunity to help students avoid injury. Often their elbows will splay outward as they lower down, rather than keeping in toward the ribcage and moving toward their hips. Straddling the student and gently pressing the elbows inward can help avoid straining the shoulders and elbows.
These kinds of adjustments, like the first kind discussed, are gentle and quick, but maybe a bit firmer because you’re trying to avoid an injury situation. Again, if the student resists or just can’t move in that direction, instruct him to keep trying, and back off – never force an adjustment!