Barefoot running, and less padded shoes, promote landing on the balls of your feet (as otherwise it's incredibly painful!). Landing on the balls of your feet allows your foot to reduce the force that gets shot up the leg.
I think the notion is to work your way up a lot slower than I did, but I haven't made the same attempt again.
I highly recommend barefoot style shoes in general, but you do have to acclimate to them slowly while you build up your foot strength.
After building foot strength in 'barefoot' shoes, I can now run much faster in any kind of shoe.
If you want an almost barefoot like experience, just get very light shoes, like middle-distance spikes, and train on tracks some of the time. Then do your long, easy miles in cushioned road shoes like a normal person.
By the way, my father recalls seeing Abebe Bikila win the 1961 Košice Peace Marathon, barefoot.
edit: An excellent video showing the subtleties of perfect form: https://www.youtube.com/watch?v=mTMgIViinuQ
http://www.npr.org/2011/03/28/134861448/put-those-shoes-on-r...
For example, keeping joints active with weight bearing exercise reduces the likelihood of developing arthritis. As other comments have mentioned, a common problem is overtraining, and especially starting out too fast. Patience is required to build up the strength and technique required to maximise benefits while minimising the risk of injury.
I suspect it's a matter of cross-training, of trying to do some compensating weight training, and luck.