The sciatic nerve is
the longest nerve in the human body. It
is made up of five separate nerve roots originating from the low back region on
each side, and runs from your pelvis through your buttock and hip area and into
each leg. It controls many of the
muscles in your legs and provides feeling to your thighs, lower legs and feet.
"Sciatica" is a
common term used to describe any type of pain/symptom that radiates into the
leg. "True sciatica"
occurs when there is a mechanical and/or inflammatory irritation directly
affecting any component of the sciatic nerve.
This differs from “referred” pain/symptoms which can
arise from a bone, joint or muscle that can send pain/symptoms into the leg.
True sciatic symptoms
may be felt almost anywhere along the nerve pathway. These symptoms can radiate from the low back
region, into the hip or buttock, and down the leg, into the calf, and even the
toes. The symptoms can vary widely and
may include: a cramping or achy feeling,
tightness, burning or a sharp electric shock sensation, numbness, tingling, and
leg muscle weakness. The symptoms may
start gradually and intensify over time.
Activities such as bending forward or to the side, walking, prolonged
sitting or standing, and even coughing or sneezing may aggravate sciatica.
Below is a brief
summary of three common causes of true sciatica:
1.
Spinal
disc herniation/bulge – Spinal discs separate and cushion lumbar
vertebra. Repetitive and cumulative
loads or a single heavy load has the potential to cause a disc bulge or
herniation, thereby causing a mechanical and/or inflammatory irritation of the
nerve root(s). This most commonly occurs
in adults aged 20-50.
2.
Degeneration
and Osteoarthritis – The normal aging process causes lumbar disc
degeneration, osteoarthritis of lumbar joints, and occasionally vertebral
slippage. The consequence of these
processes is that mechanical irritation from bony spurs and vertebrae, along
with inflammation can cause symptoms of sciatica. This most commonly occurs in adults over 50.
3.
Lumbar
spinal stenosis – This condition causes sciatica due to
narrowing of the spinal canal and/or nerve pathways. This puts pressure on the spinal cord or
nerve roots and causes neurovascular irritation. This most commonly occurs in adults over
60. It is usually secondary to degeneration
and osteoarthritis.
Other causes of "true
sciatica" include: direct irritation of the sciatic nerve by the
piriformis muscle; direct trauma or injury to the sciatic nerve or nerve roots;
and postural and mechanical changes associated with pregnancy. Some common causes of sciatic-like symptoms or
"referred" pain include: muscular trigger points and
ligament sprains from the low back, hip, gluteal and pelvic regions; sacroiliac
joint dysfunction; and arthritic low back, hip and knee joints.
Sciatica is a set of
symptoms of a problem, rather than a diagnosis for what is irritating the nerve
and causing the pain. This is an
important point to consider because the treatment for sciatica will often be
different depending on the underlying cause of the symptoms. Therefore, it is important to obtain an accurate
diagnosis from a qualified health professional.
When sciatica
strikes, there are conservative treatment options available. These may include: mechanical traction,
spinal manipulation and mobilization, soft tissue techniques, laser therapy, acupuncture,
ice/heat application, electrotherapy, and rehabilitative exercise. A qualified health professional can determine
the cause of your sciatica and prescribe appropriate therapy, exercises, and
rehabilitation strategies specifically for your circumstance. For more information, visit www.nhwc.ca.
This article is a
basic summary for educational purposes only.
It is not intended, and should not be considered, as a replacement for
consultation, diagnosis or treatment by a duly licensed health practitioner.
