Feather loss and limping - please help!

Two problems in one (and apols for posting to Chicken Chat incorrectly first off...)

One our our ladies has started limping and has lost a fair few feathers, including developing a bald patch on her back. My questions are (a) whether the feather loss is likely to be all related to feather pecking or may be moulting and (b) possible causes of and treatments for the limp,

Our three usually all have the run of a fenced off piece of the garden - around 50 sqm. Once a quarter, however, someone comes in to weed & feed the lawn and we shut them in their run for three days or so, to avoid eating any nasties. The run gives them about 1.5 sqm each - not ideal but only for the occasional day.

The feather loss started around the time that they were locked up so I am thinking that being penned up may have triggered that - anyone any experience of that? Alternatively, it could be moulting that then started the others pecking, but she is not that old (10 months or so) and I thought that they didn't moult in their first year?

Same bird also is limping a little - not badly, she is still able to put in a mad dash across the garden and she has improved since yesterday, but she doesn't look too comfortable. Anyone seen pecking damage a bird's leg? Can legs clear up by themselves or is a visit to vet advisable?

In the meantime, the afflicted chook is in segregation - as we only have the one coop, she is in a box in the run (secure from predators) overnight and in a separately fenced off piece of garden during the day. She keeps pacing the fence trying to get back to her friends but I intend on keeping this up until she regrows her feathers - is that best, or would anyone recommend isolating the pecker (who is a bid mad anyway) instead?

Thanks so much in advance for all your help.

Many thanks. A few days of isolation seem to be doing the job and now they are out and about again, all seem much happier, The limp seems to have gone. Phew!