While the intended purpose is vastly different and such concerns as shell fragments are a comparatively unusual concern in the ring, on the trail or in the field (except perhaps during hunting season), recent developments may have some downstream implications for rider helmets, equestrian, motorcycle, racing or team sports.

The basic technology for current riding helmets hasn't materially changed for as long as I've been riding -- I still find it amazing that anyone thought the obsolete traditional "hard hat" was very protective -- though I've had a couple that have aged out or were retired due to "helmet trauma".