I recently completed a long XC and upon completion I suffered a bit from sea legs. The XC was for the 250nm requirement for my instrument rating and was performed in a C172. It took about 3.5hrs to complete and there was a short ~30min pit stop a little before hr 3 of the flight. I was under the hood the entire time except for takeoff and landing. The air wasn't particularly smooth as we were only @3-4k MSL and surface winds were in the teens. I completed the flight in the early evening (~8pm) and feel like I suffered from sea legs, a small wobbly sensation of constantly moving, until I went to sleep (~11pm). I'm guessing the sensation would have lasted longer had I not gone to sleep. The sensation only occurred once on the ground and after completion of the XC. I don't recall having the sensation during the pit stop.
I'm curious how or if I should be concerned about this. I do not suffer from in flight nausea, motion sickness or anything like that.
I have never had this happen on shorter, 1-2hr, training flights. I've never had this happen when flying on a commercial jetliner. I remember experiencing the same sea legs sensation on another long ~400+nm XC years ago. I flew a plane with an autopilot that rocked back and forth as it held the heading and I attributed the post flight sea legs to the oscillations of the autopilot.
Is this common for pilots to suffer from sea legs post flight? If it is common, how long does it last? Is this an indication of a pending medical issue or an issue that might be of concern? I'm curious if this is an indication of something of concern in my inner ear. Are there any concerns with bringing this up with my AME? I have to get my medical renewed this year.