Yep, yep, yep. Me too. My right is also my symptom side, and I don't know how long I went without swinging that arm. Like you, I read something on a forum about and saw myself.

I don't know why the arm doesn't swing, but try making a point of swinging it. It might be really awkward at first. I suspect once you get the arm back into a semi-normal movement, your walking will improve. Mine did.

Mine swings normally now. How? I attribute it to 2 things.

The first improvement I noticed started after regular visits to a chiropractor. I can hear some readers saying tsk tsk, but my walking improved dramatically after starting chiropractic treatment. Xrays showed that my spine was skewed, most likely from years of picking up my weak right leg with my hip instead of the muscles that are intended for that purpose. The skewed spine is why I limp. I thought one leg was somehow shorter than the other because I measured myself at the doctor's office. I really am one inch shorter when standing on my right leg. It is quite obvious on xray that my hips are no longer even. The chiro cannot totally repair that damage (it is slightly better) but he is certainly keeping it from getting worse.

The other reason my walking is better is Ampyra. Took about maybe 2 weeks to notice that I was much more stable feeling; my balance was better, legs moved easier and quicker.

All this has my arm swinging normally, which is part of normal walking.