Thanks for the replies yesterday.

There still seems to be an issue with 3rd generation astro and back pain in girl and women soccer players. The ones I talk two say turf/grass is better but there seems to be no research on chronic back and 3G; maybe this is because FIFA has a vested interest in the success of 3G because it is a surface which can be used where grass can't be used.

Among the other variables is boot design - cleats versus studs versus moulds. Cleats seem to be more problematic on 3G, especially for girls and women.

Would be interested to hear more comments!!