Variations
In 17% of people, the piriformis muscle is pierced by parts or all of the sciatic nerve. Several variations occur, but the most common type of anomaly (81% of anomalies) is the Beaton's type B which is when the common peroneal nerve pierces the piriformis muscle.
It may be united with the gluteus medius, send fibers to the gluteus minimus, or receive fibers from the superior gemellus.
It may have one or two sacral attachments; or it may be inserted in to the capsule of the hip joint.
Read more about this topic: Piriformis Muscle
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