Patient education models

Creep and Disc Bulging

Discs are often at the core of spinal problems

disc bulging

Many clinical symptoms related to spine present themselves in a time-dependent fashion with patients often complaining of pain after a period of time standing or sitting. And often when asked, they can tell physicians how much time needs to elapse before the symptoms of pain present. In this article by Pei et al 1 they defined bulging to occur at a maximum radial rate of 2.78%±1.09. They concluded that disc creep is a very important biomechanical response and can affect spinal function.

The intervertebral disc is the spine’s fundamental structural and functional component. The gelatinous nucleus pulposus (NP) and the multilayered fibrocartilaginous annulus fibrosus (AF), which surrounds it, comprise its two primary components. Inappropriate internal hydrostatic pressure (IHP) might speed up disc degeneration. The distortion brought on by load transfer and movement has the consequence of causing disc bulging, and disc bulging deformation (DBD) is a clear sign of IHP. Instead of being a plane pressure, the IHP of the disc is a 3-D pressure distribution. Most of the data now available were gathered from plane testing and are insufficient to reflect the actual conditions of IHP. Without compromising the integrity of the disc structure, the IHP can be calculated by measuring and examining the surface DBD. DBD can be divided into the vertical, radial, and circumferential directions, represented by VD, RD, and CD, respectively, in terms of the definition of cylindrical coordinates. To learn more, visit and read their full text.

The primary deformation brought on by compressive pressure of the spine during normal daily activities in humans is creep. According to reports, disc degeneration and low back pain are directly caused by water loss from the NP that is brought on by long-term creep, which is also the exact source of the disc’s clinical height reduction. The disc bulging always occurs after the height reduction. Earlier studies on bulging during compressive pressure have presented a few findings. According to reports, the maximum RD was several tenths of a millimetre, or about 1% of the disc diameter. The anterolateral edge of the disc circle was where the RD was greatest. Disc bulging deformation has been the subject of very few investigations, despite many studies regarding height change.

Dynamic Disc Designs

Dynamic Disc Designs continues to provide spine professionals with dynamic models to help explain and understand pain generators. Perhaps “where” it hurts may not be that complicated. Our models help demonstrate dynamic disc height loss in a clinical setting when it matches the clinical presentation.

  1. Creep bulging deformation of intervertebral
    disc under axial compression