

Back Pain explains what back pain is and how it can be treated and prevented.
The sacrum is an inverted, triangular-shaped bone at the very bottom of the spine. In fact it forms the base and foundation for everything above.
It actually consists of 5 individual vertebrae that have fused together to form one large mass! It is an important structure and also works as an attachment base for many muscles and ligaments. Take a look at the illustration below to get a sense of the shape.

Any asymmetry here can have a knock on effect higher up in the chain, i.e. the lumbar spine!
Right at the base of the bone is attached the coccyx. This also consists of some fused vertebra. The coccyx doesn't really have much of a function in modern humans and is more of a remnant from our primate days!