Take two roller blades and mount them on the end of two slightly shortened crutches (leave the length adjustment mechanisms in tact - you will need them). You now have a pair of hand blades - put them on. On maximum extension you can run forward and jump onto them, lifting your legs away from the ground and coasting a few metres before giving a kick or two to maintain speed. As you gain skill, confidence and shoulder muscles you can progress to blading in a fully inverted position.
Shorten the crutches to minimum extension and put a pair of blades on your feet. You have now got quad blades - try them out. You can cruise comfortably on four blades, body leaning forward, the arms taking much of the weight. The arms also increase your speed as they skate in sync with the legs. Cornering is faster with more traction and stability is improved, but you can easily return to two blades for short sprints. Advanced quad bladers can go from normal standing position to fully inverted hand blading postion while moving forward. Some have been known to complete the move with a flip, returning the their feet through a full 360 degrees.
Acknowledgements: Inspired by [crash]'s idea for "Hand Stilts" (long baked).-- wagster, Jan 22 2005 roller ski poles Inline_20Roller_20Poles [JesusHChrist, Jan 23 2005] Four-track (and three-track) skiing http://www.patrol.o.../oec/adapt/img9.htm [robinism, Jan 23 2005] Awsome. It might also be cool to just use crutch blades and push along with your regular-shoed feet.-- JesusHChrist, Jan 23 2005 See link.-- JesusHChrist, Jan 23 2005 A handstand on rolling crutches? Sure, I do 'em all day. With my eyes closed.
This is kind of like four-track skiing, only with rollerblades. Four-track skiing uses special "outrigger" poles with skis on the bottom.-- robinism, Jan 23 2005 I'll have a go.-- skinflaps, Jan 23 2005 Nice link [robinism] - I think I'll try that after I've broken both legs quad blading.-- wagster, Jan 23 2005 If you connect the hand blades with horizontal poles and put a smal seat on front of you, then extend the blades to two metre long so you can use normal shoes to stand on the long blades. Now you have a kicksled which has been invented in Scandinavia couple hundred years ago and widely used in small country towns.-- Pellepeloton, Dec 20 2008 random, halfbakery