J-Dawg knows that the styrofoam lining inside the helmet provides the major element of head protection for a rider in the event of a fall. The styrofoam absorbs most of the impact during a fall, so your brain doesn't! Cracked, peeling or crumbling styrofoam is ineffective AND dangerous.  It is important that any hemet have a safety harness and that it fits properly. It should also be certified by the Safety Equipment Institute (SEI.)
SEI certification means the helmet meets or exceeds the American Society for Testing and Materials safety standards for equestrian headgear.

4-H requires all members to wear a helmet when mounted - for good reason! Did you know:

 * a rider's unprotected head can receive over 1000G's of force in ANY fall, at ANY speed - simply because the fall begins from th etop of a horse or pony?

* bicycle helmets should never be used as a riding helmet? Because equestrian riders are more likely to fall on the backs of their heads, compared to bicycle riders who almost always fall to the side or the front, riding helmets are required to extend somewhat lower in the back. Bicycle helmet impact tests are performed using a rounded object (to simulate a stone) that may be encountered during a road accident. Riding helmet impact tests are done with a sharp edged anvil shaped object to simulate 1.) a horse's hoof and 2.) the top of pointed fence posts that are common around riding arenas, pastures and jumps.

The bottom line is "WEAR AN SEI CERTIFIED EQUESTRIAN HELMET EVERY TIME YOU RIDE."  and always check your helmet for proper fit and condition!