EMB ERJ 170/175 ER/LR
Flight Crew Air Transport Pilot (ATP)
Communication Breakdown; Situational Awareness
Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Loss Of Aircraft Control
Flight Crew Regained Aircraft Control; Flight Crew Became Reoriented
Human Factors
At push there was confusion between the ramp agent and me. I released the parking brake before they were hooked up to the airplane. The airplane started rolling backwards and I applied the toe brakes. The system was not pressurized so the brakes did not work. I quickly applied the parking/emergency brake and the airplane stopped abruptly. The flight attendants stated the were thrown backward but did not fall down and were not injured.[This was caused by ] miscommunication between ramp and flight deck [I suggest verifying] communications with ramp
EMB-175 Captain reported miscommunication with ground crew led to the aircraft rolling backwards before control was regained.