Have had one for years after blowing out the L5 disc , Sam's Cub as well. Can't use it too much as it will start to stretch other areas,knees, ankles as well . I've got a weaker right knee and will feel it if I use it too often. Your back and body will tell you what's good or too much. I go full inverted for 3 to 4 minutes max , at about 3minutes your back will relax enough to decompress so I that's all I need ,maybe a couple of times a week. Have to be smart if injured; don't use it too soon after an injury or you may hurt more. Most times though it can help get back or stay on the water if you use it smart. Work up to full inversion over time and it can help.I believe Roger Teeter from EP Waterski fame has an infomercial on his brand of inversion table, expensive but good quality. Even the less expensive ones at the sports stores are okay , some can be found used as well for cheap. Research all you can about your back if you are prone to injury as it can be traumatic but you will find backs ( even bad ones ) are pretty durable and won't come apart if you manage them well. And as they say check with your doctor so you don't blow out a blood vessel going full inverted as well ! They're not for everybody but I love mine, keeps you young !