The term “Sciatica” is a very well known word by most individuals.  I personally hear it daily.  However, “Sciatica” is very specific condition contrary to how it is commonly used as a general term for leg pain. 

Sciatica Symptoms
The sciatic nerve begins in the lumbar spine as nerve roots (L4-S3) branching off the spinal cord.  These nerve roots combine together to form the large and very complex sciatic nerve.  Once forming the sciatic nerve in close proximity to the spine, the sciatic nerve travels down the posterior gluteal muscles then underneath the piriformes muscle.  Once exiting from the piriformes muscle, the sciatic nerve then travels down the back of the leg, into the sole of the foot.  The sciatic nerve has many other nerves that branch off of it and innervate other areas of the leg.  One way to think of it is that, in relation to the leg, the sciatic nerve is the trunk of the tree that then branches into many other limbs (nerves).  When using the term “Sciatica”, it is important to know that sciatica symptoms and sciatic pain is strictly limited to the posterior thigh (hamstring area), lower leg (calf area), and sole of the foot. 

What Causes Sciatica
There are multiple causes of sciatic pain that must be understood in order to properly treat this condition.  What causes sciatica is considered a lower motor neuron condition.  Lower motor neuron sounds complex; however, it simply means that it is a condition that originates after the spinal cord.  The spinal cord and brain neuron networks are considered upper motor neurons, and the peripheral nerves (everything branching from the spinal cord) are considered lower motor neurons.  Since it is a lower motor neuron condition, the nerve can only be affected by structures or disease starting at the outer most part of the spinal cord.  Therefore, the possible causes of sciatica pain are limited to the spinal structures, and tissue following.

The primary cause of sciatica pain is irritation of one or more of the nerve roots (L4-S3) that form the sciatic nerve at the spinal level.  This can be due to a disc injury, spinal degeneration, disc degeneration, spinal facet joint inflammation, etc.  After ruling out spinal level conditions, the final primary cause of sciatica pain  is contracture of the piriformes muscle.  As stated above, the sciatic nerve travels underneath the piriformes muscle.  If this muscle becomes chronically restricted/contracted, the result will be compression of the sciatic nerve leading to sciatica pain. 

Obviously there are many causes of “Sciatica” which is why the condition must be properly examined.  Once the underlying cause of the sciatica pain condition is determined, then and only then can the sciatica symptoms and condition be treated correctly.