If you are healthy and have no injuries then there is no reason not to sprint. Sprinting doesn't give you injuries! Running/Sprinting with bad technique gives you injuries.
Only efficient, well coordinated movement is healthy.
Assess and correct movement patterns. Physiotherapist Gray Cook:
Coach John Siffermann:
http://physicalliving.com/natural-movem ... n-perfect/
Most people are far from optimal in their movement patterns (result of too much sitting). Look for a Functional Movement Test (Gray Cook) or even better: Selective Functional Movement Assessment (SFMA) . I did the FMS test some month ago. It is cheap and easy to do.
Another cause of injury besides bad coordination is overdoing it. Your tendons, ligaments and connective tissue in general have to adapt to the increased demand and this will take some time. More time than for muscles
So ease into it. But this is also true for weightlifting, climbing, martial arts or whatever movement you do. If your training load exceeds your current capacity you are at risk.
Ageism is bad for your health. All self-limiting belief systems are. So get rid of it. Don't think you are crap just because you are over 40 or 50. You are crap because of 30 years of unhealthy lifestyle.
74 year old Ernestine Shepherd has no injuries (5ks, 10 ks, Marathons, weightlifting). She started training at the age of 56.
Madonna Buder did the Hawaii Ironman at 77. She started training in her mid forties.
I have no probs with sprints. But I watch my technique, use barefoot shoes and started to learn POSE Running. I strongly recomment using a POSE Running Coach if you have problems with running or sprinting.
For warm up I strongly recommend Joint Mobility (no - not stretching) I do it as a warm up with my dance students . It helps to transform motor morons into better movers. Your muscles do exactly what your brain tells them to do. You have to talk with your nervous system, not with your muscles.
What is Joint Mobility? Coach John Siffermann explains:
http://physicalliving.com/tuesday-qa-wh ... sifferman/
Interview with Sambo Coach Scott Sonnon about joint rehab (he had severe joint problems as a young man).
http://physicalliving.com/exclusive-int ... ng-system/