Kick sleds are, in a sense, the Scandinavian answer to winter bicycling. Kick sleds look like Zimmer frames on runners, or like a dog-less dog sled. Like bicycles, they increase the rider's speed and freighting capacity while demanding very little extra physical input. Unlike bicycles they have no moving parts and are very easy to maintain.
The operator stands behind the rear stanchions and propels herself forward by kicking between the runners. On the classic models there is always a seat to carry goods or a passenger. Kick sleds can be quite fast in flat areas, and ridiculously fast downhill. Even uphill they provide benefits as pushing a loaded kick sled is easier, and safer, than packing stuff in a backpack up a slippery road.
Though kick sled-like contraptions have been around at least since the seventeenth century in Holland (above), they only became recognizable, standardized and mass produced in Sweden in the late nineteenth century. Popularity took off in the 1920s and 30s, but they have become much less prevalent since the 1970s.
Kick sleds do demand some very specific circumstances. Not only cold weather, but also cars, or at least horse sleds, to compact the snow on roads. The runners are typically ice skate-like blades, useful mostly on very hard surfaces.
When I was a kid in the 1970s you could still see a whole row of kick sleds in front of shops or schools. The ones who use kick sleds now are mostly those champions of common sense, the same elderly women who drink tap water, eat fish and vegetables, read books, knit and live to one hundred.
I have not read any scientific studies on the kick sled, but the reason for it's demise are easy to guess at. The distance to shops and schools have increased the last decades. Car ownership has increased, not only luring would-be kick sledders away but creating worse conditions for the remaining faithful. Salt, chemicals and snow plows have also made kick sleds less useful, though some municipalities in Finland, Sweden and Norway try to reserve a part of the road for kick sleds.
In other words, kick sledding culture can only really thrive in circumstances where there are some cars, but not where there are too many. Admittedly, roads were primed for horse sledding by teams with either heavily loaded flat-bottomed sleds or enormous rolling pins. But mostly this era preceded the industrial production of kick sleds.
There's also the psychological aspect to the disappearance of kick sleds. As a technology becomes less common, the remaining users feel more and more self conscious. Who wants to be the only one to arrive at school on a kick sled? Who wants to be known as the kick sled lady?
Kick sleds are in a sense the Yiddish of transport alternatives: No war has ever been waged on them. They were predominantly used by women and children, and what existed of kick sledding competitions were always robustly humorous and tongue-in-cheek.
Kick sleds are still sold in sporting goods stores all over Scandinavia. The modern versions are always collapsible, which is good for transport and storage, but comes at the expense of rigidity. They are purchased, I imagine, mostly for their combination of nostalgia and novelty. I doubt they see more than a couple of miles of use in their lifetime.
There is a kick sled renaissance of sorts, orchestrated by the Finnish company Kickbike.
I have two kick sleds in my stable, an old classic (above) and a modern, Finnish one (below). I have wide, plastic runners that I can fasten to them so I can use them even when there is snow on the roads, and not only ice. The classic one has been modified for moderate dog-sledding use, with a drag brake between the runners and some padding up front, just in case the dogs get run over by the kick sled. (It's never happened.) The "Finn" is kept clean and streamlined.
Another history of the kick sled (in Norwegian).
Incredibly interesting pictures of my kick sleds and mods.