The call, by The Howard League for Penal Reform, is in response to Her Majesty's Inspectorate of Prisons' report on Werrington YOI.
Inspectors found the prison near Stoke-on-Trent, which holds about 120 boys aged 15 to 18, had become less safe since its previous inspection last year.
Levels of violence by young people was up compared with 2018, while use of force by staff had also risen.
In his introduction to the report on Werrington YOI, Peter Clarke, chief inspector of prisons, said weaknesses in behaviour management "have led to deterioration of outcomes in some areas".
"Managers need to make a concerted effort to support frontline staff in the challenging task of implementing behaviour management schemes, with the principal aim of reducing the number of violent incidents at Werrington," Clarke added.
The Howard League's advice line for children and young people in custody received 23 calls regarding boys in Werrington last year. However, fewer than half of those calls came from the teenagers themselves. The charity is concerned that the regime in the prison may be making it difficult for young people to access the service directly.
The most common concerns raised in calls to the Howard League were in relation to adjudications; transfers to other prisons; segregation; and treatment and conditions.
In particular, the Howard League was concerned by issues raised in calls including the case of a child who had been deemed suitable for a transfer to hospital under the Mental Health Act but was still waiting for a bed and was made to appear before the governor for a disciplinary hearing.
Another child was not provided with their prescribed medication for several days and had been self-injuring.
The Howard League was also made aware of two children who were being held in their cells in isolation - one for up to 23-and-a-half hours a day - and not getting exercise or education.
"Calls from prisons across the country to the Howard League's helpline demonstrate the unacceptable trauma that children are exposed to in custody, from lack of education to isolation and painful restraint," said Andrew Neilson, director of campaigns at the Howard League.
"If a parent behaved in this way they would find themselves at risk of a child protection investigation or even prosecution, but, shamefully, prisons are held to a much lower standard."
Neilson added that the report and previous ones "have shown prisons holding children to be fundamentally unsafe and unable to meet their most basic needs".
Last year, inspectors praised the youth work and education support provided to young people held in Werrington.
