Physical Therapy for Sciatica. How is sciatica diagnosed?
Let’s begin by first learning a little about what sciatica truly is. Sciatica is nerve pain from an injury or irritation to the sciatic nerve, which originates in your buttock and buttock area. The sciatic nerve is the longest and thickest nerve in the body. It’s actually made up of five nerve roots: two from the lower back region called the lumbar spine and three from the final section of the spine called the sacrum. The five lumbar nerve roots come together to form a right and left sciatic nerve. On each side of your body, one sciatic nerve runs through your hips, buttocks and down a leg, ending just below the knee. The sciatic nerve then branches into other nerves, which continue down your leg and into your foot and toes. True injury to the sciatic nerve “sciatica” is actually rare, but the term “sciatica” is commonly used to describe any pain that originates in the lower back and radiates down the leg. What this pain shares in common is an injury to a nerve — an irritation, inflammation, pinching or compression of a nerve in your lower back. If you have “sciatica,” you experience mild to severe pain anywhere along the path of the sciatic nerve – that is, anywhere from the lower back, through the hips, buttocks and/or down your legs. It can also cause muscle weakness in your leg and foot, numbness in your leg, and an unpleasant tingling pins-and-needles sensation in your leg, foot and toes.
Accurately diagnosing someone with sciatica involves collecting data from various sources, tests, and measures to confidently identify irritability to the sciatic nerve or one of its nerve roots while also seeking to confidently rule out other competing diagnoses. First, your healthcare provider will review your medical history. Next, they’ll ask about your symptoms.
During your physical exam, you will be asked to walk so your healthcare provider can see how your spine carries your weight. You may be asked to walk on your toes and heels to check the strength of your calf muscles. Your provider may also do a straight leg raise test. For this test, you’ll lie on your back with your legs straight. Your provider will slowly raise each leg and note the point at which your pain begins. This test helps pinpoint the affected nerves and determines if there is a problem with one of your disks. You will also be asked to do other stretches and motions to pinpoint pain and check muscle flexibility and strength.
Depending on what your healthcare provider discovers during your physical exam, imaging and other tests might be done. These may include:
- Spinal X-rays to look for spinal fractures, disk problems, infections, tumors and bone spurs.
- Magnetic resonance imaging (MRI) or computed tomography (CT) scans to see detailed images of bone and soft tissues of the back. An MRI can show pressure on a nerve, disk herniation and any arthritic condition that might be pressing on a nerve.
- Nerve conduction velocity studies/electromyography to examine how well electrical impulses travel through the sciatic nerve and the response of muscles.
- Myelogram to determine if a vertebrae or disk is causing the pain.
Care must be used when interpreting the findings of these more sophisticated diagnostic tests for sciatica. It is known that roughly 75% of all fifty-year-olds have some evidence of disc degeneration revealed in these images while over 50% will display signs of disc bulging. Arthritic changes can be found in 25% of all fifty-year-olds as well. The key is to look and the image and then look at the results of the patient’s clinical exam. If the behaviors of a patient’s symptoms correlate with the behaviors common of a disorder found in imaging then there may be some causal relationship however if a patient presents with an array of complaints that do not correlate with the symptoms that would be common of the findings on an image then it must be considered that the findings of the image may not be causal in the patients condition. It is like they say, “You can take picture of a telephone but you can’t tell if it is ringing”.