Mínimum criteria in deprivation of liberty inmates and, particularly, those relating to eventual ill-treatment, must always be contemplated in full in the disciplinary commissions, including through their videorecording if contradictory versions exist and accordingly the necessary actions must be undertaken to clarify the facts in an incidental proceeding, firstly, by the establishment itself and, later, by the specialised units of the central penitentiary services. 162. It would be advisable for the pictures taken by the video-surveillance system to be attached ex officio to disciplinary records, which could be of assistance on occasion to clarify the facts. 163. As regards serving of the penalties, this institution considers that, for the benefit of the inmates and to make the prolonged isolation less afflictive, the inmates should be allowed to opt for having at least one day of rest in the serving of punishment of isolation in cell when the punishment implies more than 14 days of isolation. 164. Both the management of CP and the central penitentiary services should ensure that the application of coercive measures is proportionate to each situation, only for the time strictly necessary and when no other less burdensome manner exists, and that they are not a concealed form of punishment. For such purpose, regular inspections and reviews of the practical application of such means should be carried out. Coercive means at the CP of Basauri (Bizkaia) 165. The application of mechanical restraints using validated belts of a psychiatric kind observed in many CP is a matter of concern since the requirements established in the above paragraph were not met and the measures of control and supervision were not adopted. 71