Lawyers for a Guantánamo detainee argued in court on Monday that the US military’s forcible feedings of hunger-striking detainees were a method of punishment, not the medically viable procedure the government has long claimed.

In the first court challenge to the controversial force-feedings, lawyers and witnesses seized on the medical records of Abu Wa’el Dhiab, the Syrian long-term hunger striker who brought the case, to show that his wheelchair, back brace and even his boxer shorts were ordered removed by Guantánamo medical personnel.

“It looks like medical care is being withheld because of disciplinary status and that should never happen,” testified Sondra Crosby, a Boston University physician who examined Dhiab last month.

Dhiab, 43, has been detained at Guantánamo since 2002, despite being cleared for release in 2009. He has spent an estimated seven years of his detention protesting through hunger strike. Dhiab’s request for an injunction to make the feedings less painful and to end the forced cell removals represent the first time a hunger striker has challenged his treatment in federal court – treatment likely to be on grisly public display, now that the judge in the case has ordered the release of videotaped feedings.

Crosby testified that Dhiab believes Guantánamo guards have forcibly removed him from his cell more than 1,300 times, a procedure he argues, like the force-feedings themselves, is painful and abusive.

Holding a 110cm length of tube before Judge Gladys Kessler, Dhiab’s attorney, Eric Lewis, said Guantánamo authorities unnecessarily strapped him in a “five-point restraint” chair and repeatedly inserted and removed the feeding tube, part of a “get-tough strategy to shut down the hunger strikes”.

Lewis quoted a former Guantánamo detentions commander, army colonel John Bogdan, saying the administration of the cell removal and hunger strikes “incentivised” compliant behaviour.

But the Justice Department attorney Andrew Warden countered that the force feeding is not a “painful procedure” and is necessary for keeping Dhiab from serious injury or death – a rationale publicly cited by President Barack Obama in defence of the force feeding last year.

Warden said Dhiab’s restraints and his forced removal from his cell – said to involve guard’s feet on Dhiab’s back – was necessary to prevent harm to guards and medical staff.

Dhiab, who stands over 6ft tall but now weighs an estimated 152lbs, has “kicked” Guantánamo staff, “thrown urine and faeces” and used “abusive language”, Warden said.

Crosby testified that Dhiab has a “complex” medical history, involving a car accident before he got to Guantánamo, that has impaired his sense of feeling on his right side. Dhiab attributes his condition to Jinns, or “nefarious spirits”.

Crosby, who is not a psychologist, said she considered Dhiab to be expressing “psychosomatic stress” and questioned Guantánamo personnel’s removal of his wheelchair – said to be temporary – walker, back brace and other medical items.

“It helps explain why the trust has been undermined with the medical staff,” she said.

Stephen Xenakis, a retired army brigadier general and psychiatrist who also recently examined Dhiab, declined to offer a diagnosis, saying Guantánamo has insufficiently examined him neurologically, and considered Dhiab’s “Jinns” explanation metaphorical.

Xenakis said Dhiab is too physically weak to pose any threat to guards or medical staff, and questioned Guantánamo procedures calling for restraints on “non-compliant” detainees. “I wouldn’t recommend any restraints,” Xenakis said.

But the Justice Department attorney Ron Wiltsie, who impugned Xenakis’s credentials in tenacious cross-examination, said Dhiab had committed “five assaults since April 2014”. According to Guantánamo Bay spokespeople, verbal abuse counts as an assault.

The first day of testimony stretched over six hours, all without a single break to discuss classified information outside of public view. The Justice Department had argued that all testimony ought to occur in closed session lest national security be jeopardised, a contention Kessler dismissed as baseless last week. Testimony is scheduled to resume on Tuesday, featuring another witness, anticipated to discuss force-feeding standards.

On Friday, Judge Kessler ordered the US government to make public 20 videotapes showing Dhiab’s treatment. The Guardian was part of a media consortium suing for those tapes. Some of that footage was expected to be shown in closed court session on Monday ahead of redactions for public release.