We used to be a normal suburban family - two cars, two kids, two bikes, two skateboards - a regular suburban Noah's Ark. My sons and I used to talk about upcoming football games, how they did in school, which park to have our picnics in - nice normal conversations. Then things started changing.

Skateboarding replaced the bikes, games, picnics - everything, including our normal conversation. I started hearing words like "flexing" and "coping" (I thought I did that just to get through each day), "Yo-Yo" and "Kryptonics" (isn't that the planet where Superman came from)? A dictionary was useless. Webster's didn't even know that Yo-Yos were precision wheels, not two discs with a string attached to them. Day by day I learned that trucks were not those large moving vehicles that roll our highways but those metal things that hold the wheels onto the decks - decks being the top of the skateboard, not where you eat lunch on a nice sunny day. Month by month, as TV Guide was replaced by Skateboarder Magazine, I would hear my boys arguing whether G&S makes a better deck than Logan Earth Ski, or whether Gull Wings are better than Tracker trucks. Soon names like Bobby Piercy and Gerry Valdez replaced O.J. Simpson and Franco Harris. I never had to complain about muddy footprints in the hallway. I did, however, have these strange grooves in my linoleum. The patter of little feet had given way to the roll of wheels.

As winter set upon us, skateboards started decorating my heating vents. This was to keep the grease around the bearings loose in the cold whether, I was told when I unknowingly returned the boards to their place in the garage. I was sure they were going to ask me to have the garage heated next.

When they started making additions to the house I knew I was headed for trouble. A board held up at a 45-degree angle by cinderblocks and wood was installed in our basement. The boys skated up the board and made a 180-degree turn on the back wheels of their skateboards. Thoughts of broken bones and fractured skulls blurred my vision and I had to put my foot down. Skateboarding was not a pastime anymore, but a sport that they were trying to excel in by learning ticks and maneuvers they had seen in the magazines or watched on TV. When they started talking about aerials I was certain they were headed for the roof. (Aerials, I later discovered, are any time the skateboard leaves the ground).

At this point, I decided that skateboarding was about as safe as skydiving, and since sky-divers don't jump without a parachute, I didn't think they should skateboard without some type of protective equipment. But what?

A parachute didn't seem appropriate, so I visited sporting-goods stores and found that helmets and pads are standard equipment for skateboarding. When I returned home with two helmets with matching knee and elbow pads, I was met with something just short of disdain. Although they were well aware of the use of helmets and pads, wearing them any place but at a skateboard park was considered "not cool." After I threatened to dismantle their skateboards, they relented. But they wanted to go to the skateboard park now that they had the proper equipment.

Have you even seen a skateboard park? It's like watching the cars on the George Washington Bridge in New York at rush hour. Young people on skateboards are zooming over concrete hills, turning and jumping, defying gravity as they're held against their boards by the Force (G force, that is). I wasn't sure my heart could take it.

Just about that time the Consumer Product Safety Commission released a study saying that an estimated 106,000 injuries in a 12-month period were attributed to skateboarding. Of these injuries, almost none occurred when the skaters had been wearing any kind of protective equipment. The study pointed out that the most frequent accidents happened when a skater struck an irregularity in the skating surface, such as a pebble, rock or crack in the sidewalk, rut or hole in the road. The study concluded by saying that more than a third of the injuries could be avoided if skateboards were used in facilities specifically intended for skateboarding. This strengthened both our cases. At least at the skateboard park they were away from the street and into full protective equipment. But as I watched some of the skaters in their hip-padded shorts, special shoes, helmets and gloves, I realized that being padded from head to toe does not make one a good skater.

So when I learned that the freestyle skateboard park in our area was starting a four week series of one-hour lessons, I insisted my sons sign up.

The sessions started with the Beginners class, and I watched as Instructer Bill Pressly gave the students a touchy-feely tour of the pro-shop, explaining the different types of equipment. Although the names and specifications of every wheel, truck and deck in the shop could easily roll off their tongues, the kids indulged Pressly just the same.

The next part of the lesson was devoted to "knowing your skateboard" and how to check it for safety, e.g., making sure the trucks were not loose, too tight, too high, too low, etc. Then the skaters put on their gear and hit the decks. After watching the riding ability of each skater, the instructor showed them how to kicktail on the walls or go over the banks, where to throw their weight and how to bend their knees to gain speed. Hesitantly, the skaters tried the walls, each at his own pace. With a lot of encouragement and patience from Pressly, confidence was gained, bad habits were broken. By the end of the fourth lesson, even the most timid skater was going down the advanced run with confidence. They had learned their limits and, on a regular skateboard Saturday, were able to go back to the park and safety skate where they felt most comfortable.

The intermediates were a different story. They came rolling in doing 360s (full turns on back wheels) and glide-slides with confidence oozing out of every bearing. But Pressly was three steps ahead. He could do 720s on the ground and 360s off the wall, so the skaters quickly learned their place. With some coaching from pressly they flexed a little more, got higher on the banks, tried 180s off the wall and even some other aerials. With no more than 10 to a class, they could to spend their four weeks perfecting techniques that they could not have even tried on a crowded weekend at the park.

Certainly not every skater can afford to go to a skateboard park, or take lessons. But many save their allowances or earn enough money to spend as much as $50 to $70 on a skateboard. Parents should insist that they spend an extra $12 and invest in a good helmet. It could mean the difference between a serious injury or just a bump on the head.

Anyway, we are back to being a normal suburban family again. The only thing that has changed is our idea of normal. We still have two cars, two kids, two skateboards; but the bikes are used less, and the only parks we picnic in are skateboard parks.

I look at it this way: What I spend at the park I save in shoes. They haven't worn out a pair in a year.