To counter the outward rotation caused by dogs running anti-clockwise arround the turns. it helps stabilises the structures.

This is exactly the same principle applied in all sports, prevent excessive rotation by supporting the weaker or more vonerable side.
If a footballer or other athlete has damaged say his medial knee ligaments the strapping should always be applied to prevent any extra strain being placed on those structures.

A lot of these ankle and knee supports sold to sports people are not neccessarily suitable for the purpose.

Em Gee.

you can run with a strapping