In 1995 a truck sliced Peng Shuilin's body in half. Surgeons managed to sew up his torso, re-routing nearly every major organ or system inside his body. Amazingly, he not only survived, but started to work towards mobility.
The China Rehabilitation Research Centre in Beijing created a sophisticated body cast [see photos] with two bionic legs attached. There is a cable attached to the legs so when one goes forward, the other goes backwards. Rock to the side, add a bit of a twist and the leg without the weight advances, and so on. He is now walking again.
It certainly puts one's niggling aches and pains very much into perspective!