Piriformis syndrome is difficult to diagnose because its symptoms are generally the same as the more common lumbar radiculopathy (numbness in the leg caused by low back pain). Both conditions are caused by the compression of the sciatic nerve. The only difference is where the sciatic nerve is being compressed. Piriformis syndrome is far more rare than low back pain, and most primary care physicians are not given much training in this syndrome. Instead, consider seeing an orthopedist, a specialist in physical medicine, or an osteopathic physician. You may need to see your primary care physician first to ask for a referral to a specialist. Your doctor may need to conduct an extensive physical exam and perform tests before reaching a diagnosis. Some tests, such as a MRI, CT scan, or nerve conduction study, may be used to rule out other conditions such as a herniated disc. To determine if you have piriformis syndrome, your doctor will begin by evaluating your range of motion by asking you to perform several exercises including straight leg raises and leg rotations. There are a number of other tests that can indicate the presence of piriformis syndrome, including:   The Lasègue sign: Your doctor will ask you to lie on your back, flex your hip at a 90 degree angle, and extend your knee straight out. A positive Lasègue sign means that pressure on the piriformis muscle while you are in this position causes you pain.    The Freiberg Sign: In this test, your doctor will internally rotate and lift your leg while you lie flat on your back. Pain in your buttocks when doing this movement may indicate piriformis syndrome.   The Pace Sign: In this test, you will lie on the unaffected side. Your doctor will flex your hip and knee, then rotate your hip while press down on your knee. If you feel pain, you may have piriformis syndrome.  Your doctor may also “palpate” (examine with the fingers) your greater sciatic notch, a notch in one of your pelvic bones through which the piriformis muscle passes. Your doctor will likely test...

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Write a summary of the previous text in Vietnamese:
Cân nhắc gặp bác sĩ chuyên khoa. Nên nhớ không một xét nghiệm nào có thể chẩn đoán chắc chắn hội chứng cơ tháp chậu. Để bác sĩ làm xét nghiệm chẩn đoán. Tìm những thay đổi về cảm giác. Kiểm tra các cơ. Yêu cầu chụp CT hoặc MRI. Trao đổi với bác sĩ về đo điện cơ.