ASK ANY SERIOUS cyclist for anecdotal evidence about the utility of wearing a helmet and you'll probably hear a story similar to the accompanying account by Dr. Lawrence Block.
Sometimes, one's head does not even have to hit the ground to be grateful. As an urban bicycle commuter of a dozen years standing, I remember thinking a couple of years ago,
as I flew over the hood of a car that had suddenly turned broadside into my bike: "At least I'm wearing a helmet." (In the end, hip and thigh took the bruising brunt of the fall, but the helmet was a distinct comfort nonetheless.)
Although Howard County's groundbreaking mandatory helmet law was modified last year to cover only people 16 or younger, most cycling authorities recommend that riders of all ages wear a helmet at all times while on a bike.
Indeed, helmets have been required in United States Cycling Federation races for several years, and bicycle racing's international authority imposed a similar rule just this year. Similarly, most organized recreational rides now stipulate all riders wear helmets.
Across the nation last week, bicycle clubs, shops and other entities marked National Bicycle Helmet Promotion Week, sponsored by the Baltimore-based League of American Wheelmen and the National Safe Kids Campaign.
According to statistics provided by the campaign, about 750 cyclists (including about 500 youngsters under 16) die from head injuries in an average year. But it is estimated that up to 80 percent of the fatalities "could have been avoided through use of helmets."
That is powerful persuasion. But the helmet safety campaign also promotes other benefits, including: protection from rain, shading from the sun, increased visibility to motorists and the fact that helmets are now part of the bike chic fashion scene, with vivid colors and designs the equal of cycling clothing.
Here are some hints for helmet buying and use:
* Don't flinch at the cost, which can range from about $30 to close to $100. How valuable is your life? Check around with various bike shops for discounts; some shops offer helmets as part of package deals on new bikes.
* Don't worry about overheating in a helmet. Earlier models were sometimes uncomfortable, but modern brain buckets designed for cycling incorporate ventilation systems to help you keep your cool.
* Get a helmet that meets the safety standards of either the Snell Memorial Foundation or the American National Standards Institute (ANSI), and preferably one that has passed both tests. Approval decals should be found inside the helmet, and most models on the market now meet at least one of these standards.
(Snell offers a free brochure listing approved helmets. Write: Bicycle Helmet Safety Institute, 4611 7th St. South, Arlington, Va. 22204-1419. The May 1990 issue of Consumer Reports magazine listed 34 approved helmets. And check any local bike shop or library for recent helmet-rating articles in both Bicycling and Bicycle Guide magazines.)
* Think about weight. Most riders who do a lot of miles now prefer a lightweight helmet whose polystyrene foam structure is covered by a fabric "net" or an almost paper-thin plastic coating. Their weight can be as low as 7 ounces or so, and racers will opt for streamlined "aero" designs that cut wind resistance.
More traditional helmets with a thicker plastic shell may weigh 15 or 16 ounces but often are more economical.
* Make sure your helmet fits, a check best done by knowledgeable personnel in a bike shop, at least for first-time helmet buyers. The importance of fit is one of the reasons that discount mail-order bike catalogs, while attractive in price, are not the best choice.
* Adjust it correctly. Many cyclists erroneously wear their helmets tilted back on their heads, like a casual cap, but this leaves the forehead vulnerable. The helmet straps should be adjusted so the rider's brow is covered but the front edge of the helmet does not obstruct one's vision. And always make sure your helmet is buckled.
* Most importantly, WEAR IT!