There are a number of factors for this. These machines, while being extremely effective for strengthening the spine, are extremely expensive, and insurance reimbursement is the same whether you exercise on a MedX machine, on a ball, or on the floor. Because of the restraint system, you need someone who is highly trained to administer the test and rehabilitation. Finally, these take up considerable room, and a lot of clinics don’t have the space. Another factor is research education. Many clinicians think they can do as much on a ball as you can on the MedX, but this is just not the case, and research proves it.