Department of Neuromuscular Examinations and Diseases, CHRU, hôpital Jean-Minjoz, 25000 Besançon, France.
Ann Phys Rehabil Med. 2013 May;56(4):300-11. doi: 10.1016/j.rehab.2013.03.006. Epub 2013 Apr 30.
The piriformis muscle syndrome (PMS) has remained an ill-defined entity. It is a form of entrapment neuropathy involving compression of the sciatic nerve by the piriformis muscle. Bearing this in mind, a medical examination is likely to be suggestive, as a classical range of symptoms corresponds to truncal sciatica with frequently fluctuating pain, initially in the muscles of the buttocks.
The piriformis muscle is biarticular, constituting a bridge in front of and below the sacroiliac joint and behind and above the coxo-femoral joint. It is essentially a lateral rotator but also a hip extensor, and assumes a secondary role as an abductor. Its action is nonetheless conditioned by the position of the homolateral coxo-femoral joint, and it can also function as a hip medial rotator, with the hip being flexed at more than 90°. The main clinical manoeuvres are derived from these types of biomechanical considerations. For instance, as it is close to the hip extensors, the piriformis muscle is tested in medial rotation stretching, in resisted contraction in lateral rotation. On the other hand, when hip flexion surpasses 90°, the piriformis muscle is stretched in lateral rotation, and we have consequently laid emphasis on the manoeuvre we have termed Heel Contra-Lateral Knee (HCLK), which must be prolonged several tens of seconds in order to successfully reproduce the buttocks-centred and frequently associated sciatic symptoms.
A PMS diagnosis is exclusively clinical, and the only objective of paraclinical evaluation is to eliminate differential diagnoses. The entity under discussion is real, and we favour the FAIR, HCLK and Freiberg stretching manoeuvres and Beatty's resisted contraction manoeuvre.
梨状肌综合征（PMS）一直是一个定义不明确的病症。它是一种神经卡压综合征，涉及坐骨神经被梨状肌压迫。鉴于此，医学检查可能会有所提示，因为典型的症状范围与躯干坐骨神经痛相对应，通常伴有波动的疼痛，最初出现在臀部肌肉中。
梨状肌是双关节肌，构成了骶髂关节前方和下方以及髋关节上方和后方的桥梁。它本质上是一个外旋肌，但也是髋关节的伸展肌，并起到次要的外展肌作用。它的作用仍然受到同侧髋关节位置的影响，并且可以作为髋关节内旋肌发挥作用，当髋关节弯曲超过 90°时。主要的临床操作源自这些类型的生物力学考虑。例如，由于它靠近髋关节伸展肌，因此在髋关节内旋伸展时测试梨状肌，在髋关节外旋抗阻收缩时测试。另一方面，当髋关节屈曲超过 90°时，梨状肌在髋关节外旋时被拉伸，因此我们强调了我们称之为足跟对侧膝关节（HCLK）的操作，该操作必须延长数十秒才能成功重现以臀部为中心的和经常相关的坐骨神经症状。
PMS 的诊断完全是临床诊断，辅助检查的唯一目的是排除鉴别诊断。所讨论的病症是真实存在的，我们赞成 FAIR、HCLK 和 Freiberg 伸展操作以及 Beatty 的抗阻收缩操作。
