I read the orthopedic physician's assistant's report on me after I went in for sciatica down my leg. There was mention of the flip test being negative. Could you tell me what this test is for?
The sciatic nerve is a large nerve that starts in the low back and goes down the back of the leg from hip to foot. As it travels through the buttocks area, it passes out of the pelvis through the a hole called the greater sciatic foramen. Pressure on the nerve in the lumbar spine area can cause pain called sciatica that travels from the buttock down the leg.
Nerve compression often comes from disc disease, especially disc protrusion. A disc herniation may also put pressure against a spinal nerve. True sciatic nerve pain from disc protrusion or herniation radiates down the leg past the knee, even going as far as the foot sometimes.
The basic flip test is done in the sitting position with the patient's legs dangling off the edge of the table. The examiner holds under the patient's heel and straightens the knee as far as it will go without putting so much tension on the nerve that it causes shooting pain down the leg. This position and movement place tension on the sciatic nerve. If it is compromised in any way, the test will be painful.
The flip test was first described 50 years ago as being positive when the patient fell backwards (flipped back) or had to brace him or herself to keep from falling backwards as the leg was straightened. A recent study of this test showed that various reactions can be interpreted as a positive flip test. For example, some patients may place their hands beside or behind the buttocks; others lean the trunk back 10 to 20 degrees. Some merely roll the pelvis back slightly. All of these reactions are in response to tension being placed on the sciatic nerve.