That river in Egypt

He tried pulling forward, but he was cuffed with his hands between the bars of the backrest of the chair. He felt around the top and the bottom just to make sure there was no way to slip them out from the bars but no. He couldn't get his arms out without breaking either the chair or the cuffs, which he didn't think he could do. Especially without alerting Rennala, who could be watching at any moment. He tried pulling at the chair hard, to see if either it or the cuffs would break. He tried to do it in a way that didn't look obvious to somebody looking at his torso and above, which is where he assumed her laptop camera was pointed at. After a few good tries, the harsh pulling was hurting his wrists and he wasn't making any progress in terms of escaping.