It is known that patients with low back pain may suffer biomechanical changes that directly influence kinematic and kinetic parameters . Therefore , it is appropriate to examine the speed , amplitude and angle of movement . Therapists and patients can benefit from the use of a device able to provide such data in a simple and flexible , making it easy to conduct and providing greater comfort to both. Therefore , we developed a device called accelerometer , which is composed of three parts , which are : sensor , receiver and software for data conversion on the computer .