Quantification of In Vivo Deformation of Healthy Lumbar Intervertebral Discs in Flexion

Intervertebral disc (IVD) degeneration is hypothesized to be the precursor to non-specific low back pain, which is a widespread problem [1]. However, before disc degeneration can be understood, a better understanding of healthy discs must be gained. The disc is a short thick-walled cylinder with a gelatinous center, the nucleus pulposus, and a largely concentric, layered collagenous ring, the annulus fibrosus, Figure 1. The layers are referred to as lamella. The IVD is integral to the strength and flexibility of the spine. Whole disc mechanics have been widely studied, but degeneration occurs at the fiber level [2]. To understand the mechanics of degeneration, testing needs to be performed at a finer level where degenerative / injury effects occur. These effects such as tears occur in the annular lamella.