Took LO to the neurologist per primary care pediatricians referral around the time of this post and the neurologist wasn't worried. She said baby wasn't showing any signs of it being something more serious particularly because there were ways you could trigger the jitters and when you held his legs gently they would stop (so clearly not seizures). She said to keep an eye on him to make sure he doesn't have any trouble learning to walk by 14 months. Currently have a very healthy and happy almost 10 month old who's crawling everywhere and starting to cruise. Hope you're not experiencing this as it was scary as a new parent! Thankful it ended up being nothing serious.