Some of the measures employed in the secure training centres, detailed in the "instructor's manual", include ramming knuckles into ribs and raking shoes down the shins, it was reported.
The contents of the manual were revealed after The Youth Justice Board (YJB) agreed to hand over the document earlier this month.
The document includes descriptions of "distraction" techniques, which deliberately inflict pain, including "alternate elbow strikes to the young person's ribs until a release is achieved."
Children's Rights Alliance for England officials said the YJB initially appealed against an order by the Information Commissioner in December 2009 that the document be given to them.
The alliance called for the Justice Secretary to order an independent judicial inquiry to examine the regimes of private child prisons going back to 1998.
Carolyne Willow, national co-ordinator of the CRAE told the paper: "The manual is deeply disturbing and stands as a state authorisation of institutionalised child abuse."
A Ministry of Justice spokeswoman said the techniques were used "very infrequently".
She explained: "For young people under 18, the use of restraint is a last resort. But where young people's behaviour puts themselves or others at serious risk, staff need to be able to intervene effectively."