CHICAGO - Jockey Rene Douglas, hurt in an accident late Saturday afternoon at Arlington Park, was to undergo surgery at 11 p.m. Central at Northwestern Hospital in Chicago after being transported via helicopter from Northwest Hospital near Arlington. \nDouglas has an injured back, according to his longtime agent Dennis Cooper, and was to have arthroscopic surgery, the concern being the possibility that a bone splinter had lodged in his spine. \nDouglas was conscious and able to speak before being sedated, Cooper said Arlington vice president Bill Thayer had told him. Douglas was able to move his arms, but apparently had experienced some degree of paralysis after the fall. Cooper said earlier in the night that Douglas could feel his feet, and was able to feel pain in his back and arm. The surgery was to last about two hours, Cooper said. \nDouglas was thrown to Arlington's Polytrack and rolled on by his mount, Born to Be, at the top of the stretch in the Arlington Matron. Born to Be raced just in behind the lead pack and appeared to be running evenly when she turned into the stretch. Born to Be was about two paths off the rail when jockey Jamie Theriot on rail-skimming Sky Mom tried to go through a hole inside Born to Be and outside eventual winner Euphony. Sky Mom bumped Born to Be, who was pushed out and clipped heels with tiring pacesetter Boudoir. Born to Be lost her footing, fell, and flipped over, rolling onto Douglas, who remained pinned beneath the horse until being extricated by track personnel. \nBorn to Be also might have hurt her back, trainer Eric Coatrieux said Saturday evening, and her condition also was uncertain. Coatrieux said the horse had tried to stand up and had to be sedated in the horse ambulance, but once at Arlington's detention barn, the filly appeared unable to stand.