A prisoner with a muscle-wasting condition accused of taking part in a Palestine Action protest claims he has been forced to crawl around the jail – including to get medicine – because of lack of treatment and a wheelchair.

Umer Khalid, who is being held at Wormwood Scrubs in west London, awaiting trial for alleged involvement in last year’s break-in at RAF Brize Norton, also alleges he was left in his cell when the prison was evacuated because of a fire alarm and went 26 days without a shower while waiting for a shower chair to be provided.

In an interview from prison, the 22-year-old from Stockport, who has limb-girdle muscular dystrophy and is not due to stand trial until January, compared his predicament to that of an injured stray dog he saw when visiting Pakistan.

“It genuinely broke my heart,” he said. “I felt so sad because no one’s going to care about it, it’s just going to have to crawl with this injury. It feels worse than that because at least when I looked at that dog, I felt sympathy.

“I’m literally on the floor, crawling on my hand, but then I can’t even use my right arm because I’ve fallen on my shoulder multiple times because they’ve not given me a wheelchair, so I can’t even crawl properly.

“I’m not embarrassed because at the end of the day I’m not the one who should be embarrassed, but it’s so dehumanising.”

Khalid says the muscles in his arms and legs have wasted away such that skin is hanging off his bones, a description confirmed by recent visitors.

He claimed he waited weeks to be given crutches, which he is now too weak to use, and then for a wheelchair, which is unsuitable because it does not fit in his cell or in the corridor outside it.

For a while, he was able to use the wheelchair but he says he fell out of it twice trying to get into his cell. He said he was told last week that it was only to be used for going to see visitors and appointments, which “has led me to have to crawl on the floor to get medication”.

Before he was given the wheelchair, Khalid, who says he is in pain and exhausted, missed appointments with the neurologist and the physio because he could not get to them. He said he has only seen the physio once this year.

When there was a fire alarm on 23 April, he claims prison officers, “just looked at me, saw me in bed and left. But I was in too much pain to even get up and press my emergency buzzer”.

He said a neurologist recommended supplements a month ago, which he had not received and he had not been given the high protein food he needs for his condition.

Despite being diagnosed with muscular dystrophy in 2014 Khalid, who was part of a hunger strike by Palestine Action-affiliated prisoners that ended in January, alleged healthcare workers had accused him of exaggerating his condition and communicated their belief to prison officers.

He is demanding proper medical treatment, full access to a suitable wheelchair and the release of all his medical records to his legal team.

His mother, Shabana Khalid, said: “He showed us his legs and his arms, he’s just like a skeleton with skin hanging off him and the prison want to say he’s making it up. It’s horrific; there’s nothing we can do but get angry.”

A Ministry of Justice spokesperson said: “The Prison Service caters to all disabilities. All prisoners’ needs are assessed when they enter custody – with arrangements made, and appropriate action taken to ensure they are met.”