Anyone have experience or informed opinions on the use of Inversion Tables for therapy for low back issues, such as lumbar disc bulge and/or herniated disc, sciatica? The concept seems to make sense, stretch the spinal vertebra to take stress of the discs in the spine. Have been looking them over, "Teeter Hang-Up" is the #1 brand......although my orthopedic doctor advised against using them, with concerns about hyper-extension or stroke. tia