Walking without a leg

I do have a strong interest in amputees, particularly those who have lost a leg, I know.  The progress we have made in building prosthetic legs in the past 50 years has been amazing.  Oscar Pistorius' ability to compete with two-legged track stars is certainly not something I could ever have imagined.  Now it seems that the type of legs Pistorius uses is probably better for walking with a prosthesis than what has been typically accepted - a leg whose foot mirrors man's natural foot. English scientists have published a study demonstrating this proposition.

Jim Usherwood, the lead scientist tells us, “If you want to make a good prosthetic foot but don’t care what it looks like, you should put the motor — in this case the ankle — as far up the leg as possible.”  When it is higher up, the ankle “can provide the power without making the feet heavy and hard to swing backwards and forwards”.  Their model for this new type of prostheses is Pistorius as well as another 'walker' - the ostrich.

Apparently, apes and men walk differently than other bipeds.  We, says Usherwood, "walk by crashing on the heel, vaulting over the stationary leg and then pushing off with the toes".  The ostrich has no heels, his tendons act as springs; this allows the ostrich to walk faster.  Such a system is more efficient when you don't have a natural leg.