Hi, (Amber)!
First off, I hope you had a great time at the concert, despite the after effects you experienced from standing that long. So, unusual feelings like pins and needles, stinging, itching, and the like is often lumped under the term dysesthesia. You can read a bit about it here (along with other kinds of MS pain) -- https://multiplesclerosis.net/living-with-ms/types-pain-symptoms. And here's a conversation from our forums on the topic of tingling knees and legs -- https://multiplesclerosis.net/forums/tingling-buzzing. I would say that you can follow up with your general practitioner or keep your MS doctor abreast of any changes. While the knee sensation could be related to your MS, it could also just be a one time thing or related to something else altogether. So, you can keep an eye on it, note if it happens again, and have your doctors keep an eye on it. I am 49 and though I am pretty healthy, I will say that my legs aren't fond of hours of standing anymore and let me know the next day, but it's a passing pain/swelling. Some things may be related to our age or again, other issues (my blood circulation could be better). I think it's smart that you are aware of what happened and talked to your MS doctor about it. Did you have any other symptoms, like swelling, severe pain, stiffness, numbness, etc? Are you still experiencing the sensations? You don't have to answer these questions here if you don't want to, but they would be good to note for your own records.
I do hope this was just a passing thing and your body just telling you, "Our days of standing through that encore of Freebird after two hours of standing in a full crowd may be behind us, Amber" and not an MS issue!
Best, Erin, Team Member.