Sledge Hockey or "sled hockey" as it is often now referred to, has been played in Canada and the United States for well over several decades now.  Teams and clubs are springing up throughout the major US markets, usually with the help of their professional NHL teams.   Players, who have physical disabilities, sit in sleds with two blades on the on the undercarriage of the sled and propel themselves across the ice with two short hockey sticks with ice picks on the bottom.  The game differs from ice hockey only in equipment and period length (periods are 15 minutes instead of 20).  Full hockey protective gear is worn as the rules of contact are the same.