|The highback is not so much a lever to lean against, as a means of maintaining a certain degree of ankle mobility and knee flexion. If the knees are too flexed, a less effective posture and muscle tension will be the result. If the knees are not flexed enough, range of movement and balance will suffer. The idea is to find the degree of flexion where the joint facets, and then support this posture.Stand with the front foot buckled into the binding, with the hips facing the direction of the foot. Set your rear foot next to and parallel to your front foot. Imagine that you have to stand around for a long time without sitting down. Find the degree of knee bend that feels the least muscular.
Set the forward lean of the highback to support this posture. If you have to straighten your leg to feel the highback, go one click forward. If, after standing there for a minute or two, you want to straighten the leg to reduce fatigue, back off by one click.
Of course, based on the volume of the tissue at the back of the lower leg, and the chosen boot, the boot may need to be modified at some point to affect knee flexion.