EMB-175 ramp crew reported momentary aircraft loss of control following push back from gate and tow bar disconnect.

Narrative

On Day 0 at approximately XA:15 EST myself (push back driver); right wing walker and left wing walker were preparing to dispatch Aircraft X (ZZZ-ZZZ1); operated by Company. While preparing for push back I discovered the headset in the push back was able to hear communications from the flight deck but was unable to transmit communication to the flight crew; 'can receive; can't transmit'. Upon discovery I went to the next gate over from ours to borrow the headset in that gate's push back to see if a new headset fixed the problem. After connecting the new headset I was still faced with the same problem. At that point I informed our Crew Chief that we needed their assistance to use hand signals. The Crew Chief and the Captain both reviewed the hand signals to be used. A few moments later we began the push back after they received brakes release and cleared to push from the flight crew which they relayed to me. I then honked my horn to signal to my wing walkers that the push was commencing. The Crew Chief next gave the crew the signal to start #1 engine. Upon successfully pushing the aircraft on the taxi line I brought the push back to a complete stop. I then looked to my rear and observed the left wing walker give the set brakes signal to the crew and then display the standard x with their wands. I then looked forward to the right win walker. At that moment I focused on the brake indicator light to ensure brakes were set which would display a red light. I observed that the green light was still illuminated indicating brakes not set. I immediately pointed to the brake indicator attempting to make the right wing walker aware that brakes were not set. I avoided using the symbol for brakes released in order to avoid any miscommunication between us. The right wing walker misunderstood my pointing to mean they could disconnect. They then disconnected the tow bar. Just before they did I made a last attempt to stop them by blaring the horn to gain their attention. Upon disconnecting the tow bar the plane moved forward no more than one foot which the crew didn't notice immediately. I attempted to reverse the push back to avoid contact between the tow bar. We cleared the area of debris and advised ops that the aircraft should return to the gate to be inspected. No damage was found by the Mechanic who conducted the inspection; the tow bar had to be removed from service for repair. It should be noted that the left wing walker never received any response from the flight crew upon giving the signal to set brakes.Event occurred primarily due to headset malfunctions. In addition; the flight crew didn't respond to the wing walkers signal to set brakes. Along with RH wing walker assuming a non standard signal was being substituted for a standard signal. A non standard signal was only used due to the situation to draw attention to the brake light to avoid disconnecting while brakes weren't set. Crew Chief; Ops and Manager notified that plane must return for inspection and the tow bar was tagged out. A standardized hand signal for push back drivers to use to communicate to disconnecting wing walker. Signal should convey to the wing walker to immediately stop any action and communicate with the driver about potential hazard. A standardized signal would eliminate potential misunderstanding.