Best shoes ever. I can only wear shoes with springs due to 3 herniated disks in my back. Period. No other shoe works unless I bear with extreme pain. Spira brand works well for me. No pain. Long use. Ive gone on vacation walking 8 hours a day and no pain in my back! None. Zero. I bought these so I don't have to wear the sneaker kind while wearing skirts and dresses. Im 40 years old 170lbs 52. Ive heard they are good for knees but I have no knee problems, my problem is all extreme lower back pain. As in so painful I cry for hours.