Thank you for your reply.. I know that its basic common sense at this point..and I truly want to believe it is purely muscle related so i will rest for a few days.. NOT sure that the incredibly light work out at the gym was to contribute… I think it was just me not being warmed up enough to complete my posture One of those things????.. just never had an injury from a class before and its no fun as anyone would imagine.. its more devastating to me mentally than physically.. .. aaaaargh.. Thank you so much for your reply and advise.. I love your website and information.. really great stuff.. Namaste, Lisa