If we focus on finding and treating the source of pain, we can speed up recovery AND prevent further aggravation of LBP. Since we know that muscle spasms are the most common cause of LBP, determining which muscles are involved is usually the most important step in designing a treatment program.

The muscles most commonly blamed for LBP are the paraspinals. These muscles are commonly injured (poor posture, prolonged sitting, repetitive or heavy lifting), and are the primary source of short duration LBP, but are not usually the source of intense long duration (weeks/months) pain. The paraspinal muscles are the muscles that run next to, and roughly parallel with, the spine.  Together with other core muscles (muscles that wrap around the chest, abdomen and pelvis) they help support the spine and keep it in proper alignment.

When a person experiences a back spasm, it is often a paraspinal muscle tightening up, which is a warning signal that his back is either bearing more weight than it should, or bending and twisting improperly. Skeletal muscles work in pairs. While one muscle is contracting, or getting shorter, another muscle must get longer to allow movement. When a person bends forward, his paraspinal muscles are lengthening; when he stands up again, they are contracting to pull him back to a standing position. So if your back hurts when you bend forward or twist, the paraspinals are likely involved.

But what if your back hurts when you try to straighten your spine/stand up? Even though the paraspinals are often blamed for this type of pain, they are not the muscles causing the pain. Muscles in spasm do not like to be elongated, they prefer to be in a shortened position. Bending forward elongates the paraspinals—which would increase the pain. So the muscles causing this pain are muscles that elongate when the spine is straight (as in standing).

I will discuss these muscles in Part 3 of “Low Back Pain”.

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