Kangoo Jumps KJ XR3, Black and Orange, Size SMALL Womens 4,5,6 Mens 3,4,5

I got them due to a torn knee ligament which still hurt after it healed when I ran. These shoes were designed for rehab runners and I can certainly say that the pain is now gone after my run. It has also shortened my workout time by about half since it takes more energy to run in these. Each shoe weights about 5 lbs., so it''s like running with weights on your feet. Do not expect to run fast or race in these due to the wt. and the balance. The bouncing may upset your stomach--I drink only coffee which ended up sloshing around. Yes you do use different muscles because you need more lift(due to the weight) to run. It feels like a combination of running and cycling muscles--its a great workout. I''m giving it 4 of 5 stars because I think future models will weight less and the top shell will be softer.