The first thing you notice about Lance Corporal James Simpson is not that he is missing both legs or most of his left hand. It's the smile on his face as he walks tall across the garden at Headley Court using his new prosthetic legs.
"It's really, really hard work," says James, 23. "But when you go from lying in a bed in Selly Oak Hospital for 10 weeks not knowing what's in store for you, to being able to get up in the morning and put your legs on and just walk about, it feels great to slowly start reintegrating yourself into normality."
The servicemen working out in the Waterloo gym at the Headley Court rehabilitation centre, near Epsom in Surrey, may be injured, but they certainly don't lack determination.
As the PT instructor barks out orders, every man gives his all, even though many are missing a limb, and several are missing two or three.
Kate Sherman has been a physiotherapist at Headley Court for seven years, and remembers when she and her colleagues mainly treated patients for sports injuries, or after car and motorbike accidents.
Back then, just two amputees were being cared for here, but that number has risen inexorably since the wars began in Iraq and Afghanistan.
In 2006, when British troops first went into Helmand, seven returned with limbs partially or completely amputated.
By 2008, it was 30, and last year, in 2009, it rose to 55.
Kate admits it's been a challenge for the therapists too, but she says the servicemen and women she treats are remarkable people.
"On the whole, they're massively positive. The majority of the time it's 'Yes, I have got horrific injuries, but I want to make the most of it, I want to get on with my life, I want to be able to do things.'
"So they're very proactive, they're forever pushing us to find more ways of doing things and find more things that they can do."
Thanks to advances in battlefield medicine, and the dedicated medical and therapeutic teams at the field hospital at Camp Bastion, Selly Oak Hospital and Headley Court, the number of servicemen and women surviving their injuries in Afghanistan has risen.
Those needing - and surviving - multiple amputations rose fourfold last year, from six in 2008 to 26 in 2009.
Ken Bellringer, 39, was working in bomb disposal - one of the most dangerous jobs on the front line - on the day his life changed forever last November.
"There was an almighty explosion, and everything slowed down for me," he says. "I felt like I was rolling through the air, and I remember thinking, 'This is going to hurt', and I landed.
"I remember being in the helicopter and someone held my head and they said, 'We've got you', and I fell asleep. The next thing I remember is waking up in Selly Oak just before Christmas."
Ken lost both legs and suffered many other injuries, including the loss of both his thumbs, which makes many tasks difficult. But he is full of praise for the work of Headley Court.
"It's a fantastic place because there are people in the same boat as you, and there is that selfless commitment that's engrained to help each other.
"And you don't feel sorry for yourself because there is always someone else who is worse off.
"You have to deal with what you've got. People here are very resilient. They're soldiers."
Ken has just been allowed home in Didcot, Oxfordshire, to stay with his wife Christine for two weeks for the first time since he was injured.
Their new Army quarters will need to be adapted, so that Ken can return home for good. But the waiting for that to happen has been tough on his family, and Ken says that in some ways it has been hardest on Christine seeing the full extent of his injuries.
"I asked her once when she knew I'd survive, and she said not till I was on the ward. So for five weeks she'd had the thought of me dying and still had to look after our two children.
"The brave one for me is Chris."
The Commanding Officer at Headley Court, Col Jerry Tuck of the Royal Army Medical Corps, says the rehabilitation centre has had to expand to deal with the demands.
Before the campaigns in Iraq and Afghanistan began, it had just 36 in-patient beds. That rose to 66, and by the end of this summer, there will be 96.
"I wouldn't say the sky is the limit, but we have lots of contingencies in place and I'm confident we can meet all the calls for the needs of our wounded service personnel," Col Tuck says.
"We feel that what we're doing here is of national importance, because of the moral duty we have to our wounded service personnel - but we would far rather send somebody back to work than have them dependent on social care at home."
Col Tuck is looking forward to the opening of the new swimming pool and gym complex at Headley Court next week, funded by the charity Help for Heroes.
"The success of the Help for Heroes charity exemplifies the public profile of our wounded service personnel. There are more of them, and society is getting used to seeing them."
Earlier negative reactions to the sight of injured soldiers in a local swimming pool, and to the building of accommodation for their families at the nearby Norton House, have turned into staunch support from local people for Headley Court and its residents.
"Some of our wounded service personnel have been terribly mutilated. They're not going to stay indoors until the end of their lives, they are going to go outside and embrace the world and live their lives," Col Tuck says.
"The rest of society has got to get used to seeing them out and about."