When lifting heavy objects we put a massive load on the lower back and as a result the most commonly injured tissues are the intervertebral discs of the lumbar spine. These intervertebral discs are located between each vertebral body in your spine and therefore act like cushions between the bones. These discs have a very unique structure that can be best explained by picturing a jelly donut. The inside of the disc is made up of a soft material and the outside is made up of a thicker tissue that is actually layers of rings packed tightly on top of each other. The fibers of these rings are angled at 45-degrees with each ring alternating the direction that the fibers are running, creating X-like patterns. These alternating layers of rings become vital to the health of your discs.