"My doctor advised me that it would be very detrimental for me if I were to ride again, so I guess that's it," Murphy said. "I have a spur in my neck and, if I go down again, they say it could sever my spinal cord.
"I'm sad about it, but at least I can walk."
She retires with 1,833 career Thoroughbred victories, according to Equibase, which ranks fourth among female jockeys.
Murphy, then known as Cindy Springman, won the first race held at Prairie Meadows on March 1, 1989 aboard Holmish. A native of Muscatine, La., she won 805 races at Prairie Meadows and is second to Glenn Corbett among the track's career riding leaders.
She won 112 races at Prairie Meadows in 1998, which at the time was a track record. She holds the record for wins by a female rider at Oaklawn Park with 47. She won riding titles at the Iowa track three times.
"She's been the First Lady of Prairie Meadows as far as I'm concerned," trainer Larry Hunt said. "She's a terrific race-rider."
Despite that, Hunt said he was glad that Murphy didn't risk further injury.
"I think it's a wonderful choice," he said. "She's a wonderful girl, I love her like my daughter, but she's been beat up so bad and hurt so many times, that I think it was time to retire.
"She has three wonderful children. She has a lot of reasons not to be crippled. The last one was a pretty scary deal."
Murphy's May 11 injury came when her mount, Ninnescah, stumbled coming out of the starting gate and was then hit by a horse veering outward. The shift in momentum sent Murphy flying headfirst to the ground.
She lay motionless for a half-hour before being taken away by an emergency helicopter, the first time one has been needed at Prairie Meadows for a racing injury.
Murphy said that she is regaining movement and strength in her limbs.
"I still have a lot of arm weakness," she said. "I can do all the day-to-day light stuff, but I can't lift much and struggle to grip stuff with my hands.
"They're hoping that with time it will get back to normal, but you never know. They tell me it could be a month, a year, or never."
Murphy is with her husband, Travis, at their Jones, Okla., ranch while she decides which career to pursue next. She hopes to eventually return to school to pursue a career in nursing.
Prairie Meadows Chaplain Dennis Luft is sponsoring a silent auction to help Murphy with her living expenses. It will be June 16 during the chaplain's picnic that starts at 11 a.m. in the track kitchen.