"She had a little brain bleed when she was in NICU (neonatal intensive care unit) which sometimes can cause nerve damage in the brain, which mean the messages aren't getting from the brain to the muscles, which can cause a mild cerebral palsy," Sam explained to the hosts.
"The deal is, if you can get to it early enough then the plasticity of babies' brains means they can recover."
Sam was then asked if Imogen is in the clear, to which Sam said things are looking positive.
Sam said, "Early intervention is key, lots of exercise and lots of physio, we've done that for the last year.
"She was really stiff in her legs and arms. It's just been getting that out of her, she couldn't squat, she was always up on her toes and her toes were far back. We went to a physio a couple of weeks ago, Immi's come so far.
"She's walking really well at the moment, so at the moment it looks as though it won't be the case. Touch wood, because I keep thinking things are getting better and then there is something else."
Imogen was born in June 2017 weighing just 1.3kgs.
For more parenting news head to the Practical Parenting site.