In the How does it work section, we explained (briefly) how the backrack works. To explain this in detail, however, we must first describe the structure of the human spine and the main, underlying cause of back pain. From this, the design principles of the backrack™ will become clear.
The human spine consists of a number of vertebrae, or units of bone, arranged in a vertical structure. A structure known as the spinal column.
In new-born children, the column comprises 33 distinct, or physically separate, vertebrae. Over time, however, the units at the base of the column fuse together to form the coccyx, or “tailbone”, and the sacrum, which forms part of the pelvis.
As can be seen from the diagram, the column itself actually consists of five, distinct, regions. These are known (from top to bottom) as the:
- cervical spine (red)
- thoracic spine (yellow)
- lumbar spine (green)
- sacrum (turquoise)
- coccyx (dark blue)
The mechanical function of the spine is two-fold: it must provide structural support for the body, and allow us to move freely in three dimensions (bending over and rotating as necessary).
In order to achieve this, the vertebrae in the top three sections must be allowed to move relative to one another, without compromising the structural rigidity of the back. This is achieved by the use of facet joints, which lock the vertebrae together whilst allowing for articulated movement (an articulated lorry provides a useful analogy).
The joints are referred to as facet joints, because they are formed when the faces of two bones come together. Contrast this, for example, with the hip joint, which consists of a ball and socket.
Facet joints are very good at allowing a broad range of movement. For example, they allow us to bend forward, backwards, and to the side; they also allow us to rotate (both to the left and to the right), and to combine these different movements. Compare this, for example, with the knee, which only allows for bending in one direction: you cannot bend it to the side, or rotate it very far.
Unfortunately, facet joints can also be compressed relatively easily (where the faces slide too far towards each other). When this happens, the vertebrae in the spine can no longer move freely; in turn, this prevents us from moving freely. Put simply, we become stiff. In addition to this, we experience back pain. In actual fact, up to 98% of all back pain is either caused by, or directly linked to, compression of these joints.
If you would like to understand this in more detail, please visit our section on the Back Anatomy.