Bones waste/burn/tremble/rejoice
Here’s what it means
The deepest strength of the person is pictured as suffering, shaking, drying up, or being restored.
Why the Bible says it this way
An idiom is a familiar phrase whose meaning comes from the whole expression, not from reading each word by itself.
A helpful detail: Some physical effects may be real, but “bones” often represents the whole person’s deepest vitality.