Can Anataflex Be Harmful To The Body?

IS THERE ANYTHING IN SNSTAFLEX THAT CAN BE HARMFUL TO MY HEATH...i RUN ON A REGULAR BASES, BUT SINCE I HAVE A JOB THAT REQ.ME TO STAND ON MY FEET 8HRS A DAY, MAY KNEE HAS BECOME VERY SORE..i HAVE PURCHASED A GREAT PAIR OF SHOES FOR STANDING , WHICH DOES HELP SOME....