Hi Sam, welcome to hogaholics forums.
I have several that scratch themselves frequently and I don’t worry about it to be honest. I also capture footage on trailcams but remember at this time of year, lots of plants are setting seed so in their foraging journeys, they will be picking up seeds and weeds of course. I put it down to that because so long as they are scampering well, [they can’t half run] then they are fine.
The only worry is if they get mites which can be a real nuisance and cause agonising pain but it is not detectable to the naked eye, so trailcams won’t be much use in determining if the hog has mites. Fly strike is the other hazzard and that’s where maggots are evident. If you see anything of that nature it needs professional help immediately.
Hope that reassures you.