This interactive video allows you to see what a typical lumbar herniated disc [1] looks like. A herniated disc [2] in the lower back can cause lower back pain and/or leg pain (sciatica [3]) by putting pressure on the nerve root.
Links:
[1] http://www.spine-health.com/Conditions/Back-Pain/Common-Causes-Of-Back-Pain/Lumbar-Causes/Lumbar-Herniated-Disc.html
[2] http://www.spine-health.com/Herniated-Disc.html
[3] http://www.spine-health.com/Sciatica.html