As someone that used to write chits, I was pretty specific about stuff - after the tick in the box, I'd often then amplify to be unambiguous; I didn't have all day to spend on the phone or email because someone had problems putting words together in either official language.
I basically said no PT if that person was literally in a body cast or was on a specific rehab program (like post heart attack or something) and even most of those were "medically directed/supervised PT". PT at own pace means just that - you go at the speed you can. Whoever is leading the PT can have you do it with the group at your speed/ability or send you off to do modified activity - but that's their prerogative to give , not yours to assume. If you've got specific restrictions based on the injury or illness, they need to be specified - if you can march but shouldn't carry a ruck, you'll be given no ruck marching as a restriction or maximum weight restriction attached (FFO vs marching order or something like carrying no weight >/= 10kg), what body bits can be exercised (self or medically supervised upper body PT only for instance). If you're self-directed, then you go do your thing...but do actual PT, not arm curls with your 2 large double doubles.
You'll note that you'd literally have to be on death's door to get a full excused PT chit from me - I'd actually discuss that with the Base Surgeon if something remotely looking like that came up, as exercise is actually medicine and progressive exercise is necessary to recover from injuries, surgeries and some illnesses...and being able to exercise and be fit is a mandatory requirement for military employment. Most people like that are on some Temp or PCat.
Don't get me going about the folks that were on "athletic scholarships" that were asking to be excused runs and ruck marches but be able to keep playing full contact hockey, rugby, unarmed combat or other full contact sports...hence what Jarnhamar notes about being treated like supervised adults vs like normal everyday ones.
:2c:
MM