Load management is one of the keys to any injury. Finding the right point is an art and can only be done well with significant patient education and involvement. If we rest to much we detrain, let muscles atrophy and even let our bones density(osteopenia or osteoporosis). Ligaments and tendons also get weak and osteopenic. We need to thread the needle between adequate rest and training.
Part 1 knee
For those of you that want a deep understanding this is a great lecture about what works to heel and diagnosis knee pain. With an emphasis on training load
Here is a synopsis