CRJ-900 First Officer reported rudder pedals jammed and were hard to actuate on taxi. The flight crew elected to return to the gate for maintenance.

Narrative

On Date; I was working as FO (First Officer) with Captain Name. I was going through OE training; and this was my first week in an actual CRJ-900 cockpit. When I arrived at the aircraft for the preflight inspection; a Company maintenance employee spoke with me and informed me the aircraft had just come out of maintenance. I believe he also mentioned the tension on some cables had been tightened. I then completed the [remainder] of the preflight procedures. Later on; we had pushed from the gate and conducted the After Start Procedure. Captain checked the rudder function during this procedure. He notified me that the rudders felt stiff and he was not able to get full rudder movement. He asked me to check my rudder pedals. I performed the rudder check; and I noticed the pedals felt stiff. I could get full rudder movement indicated on the flight control synoptic page; but only when I gave a considerable amount of force. I mentioned this could be a result of the cable tightening from Maintenance; and I said this was my first week in the cockpit; so I did not have much experience with what the normal feel of the rudder pedals is like. There was also another Captain observing this from the jump seat. I do not remember his name. Captain asked that Captain to check the rudder pedals as well. He did so; and the results were still inconclusive as to whether the rudder function was acceptable. Captain checked the rudder function a few more times; and he said he did not like it. Captain made the call to head back to the gate and have Maintenance look over the issue. We were then informed by Maintenance that a pin had been unintentionally left in the rudder controls after the maintenance was complete. They removed the pin; and we checked the function of the rudder pedals again; and we determined the rudder was properly functioning at this time. We this proceeded with the remainder of the flight to ZZZ1 without incident.I like how maintenance personnel greeted me as I arrived at the plane. They informed me of some of the work they had performed on the aircraft prior to the flight. This information helped in our decision-making process to determine that something may not be correct after the maintenance was completed. I would suggest that the maintenance crew be very informative when talking with flight crew about what work had been completed on the aircraft.