Piriformis muscle

FIG. 65-1 PINS sacrum and pelvis point patterns. Posterior I, piriformis muscle 2, Iliotibial band 3, sciatic nerve/ posterior femoral cutaneous nerve/hamstrtng muscles 4, gluteal muscles 5, sacroiliac. 

The lateral rotator muscles of the hip include the piriformis and the obturator internus. The piriformis muscle has its medial attachment to the lateral border of the sacrum and is often involved in sacral dysfunctions. 

The piriformis muscle lies deep to the gluteal muscles. It originates on the anteriolateral surface of the sacrum, joint capsule, and anterior sacrotuberous ligament and attaches to the superomedial surface of the greater trochanter of the femur. It is an external rotator and abductor of the thigh. This muscle has an intimate relationship to the sciatic nerve, which passes just beneath it, or, sometimes, through the muscle belly or between two tendinous origins of the piriformis. 

Hypertonicity or spasm of the piriformis muscle may cause irritation of the sciatic nerve, sometimes to the point of causing neuritis. Although the sciatic nerve most typically passes inferior to the piriformis, normal variants exist with its passage through or posterior to the piriformis muscle. The sciatic involvement often causes confusion between piriformis syndrome and a disc herniation. 

Muscle strengih in external rotation and abduction is generally normal but may exhibit some decrease. The muscle and Its attachments are tender to palpation. There are three counterstrain lender points associated wiih piriformis syndrome mid-pole sacrum, piriformis muscle, and the posteromedial trochanteric point. 

If a patient does not respond after several treatments, it is important to search for some activity the patient is doing that is either aggravating the piriformis muscle or causing a sacral dysfunction Oiat puts abnormal tension on the muscle. Rarely, the obturator muscle is involved and mimics piriformis syndrome. This may need to be ruled out in obstinate cases. 

Piriformis. The piriformis muscle originates on the pelvic surface of the sacrum, at the margin of the greater sciatic foramen, and at the sacrotuberous ligament. It inserts on to... 

This point needs to be looked for whenever there is a piriformis syndrome or with a tender point in the belly of the piriformis muscle. 

The patient was treated using facilitated positional release techniques for relief of the muscle hypertonicity as well as the restrictions and somatic dysfunctions found. Special attention was given to the treatment of the piriformis and tensor fascia lata muscles. A prescription was given for nonsteroidal antiinflammatory (NSAID) medication. 

This tender point is palpated by pushing the monitoring finger medially on the lateral edge of the sacrum at the midpoint between the posterior superior iliac spine (PSIS) and the sacral apex. This is at the site of the piriformis attachment to the sacrum and probably represents a second piriformis tender point, it is often found in association with the tender point in the belly of the muscle. 

Clinically, a hypertonic piriformis is correlated with a posterior inferior lateral angle [11-A] on the same side. The muscle could be significant in causing or maintaining sacral somatic dysfunctions. 

On examination, the left buttocks was lender to palpation and there were tender points at the mid-pole of the sacrum on the lateral border and one deep to the gluteus maximus, where a lense piriformis could be palpated. There was a unilateral sacral flexion (sacral shear) present on the left. No lumbar somatic dysfunctions were present. There was mild tenderness at the sciatic notch of the ischium. Deep tendon reflexes were normal and muscle strength of the ihigh was normal. There was some pain on internal rotation and adduction of the left hip. 

Left piriformis syndrome was diagnosed and was treated with osteopathic manipulation. The sacral shear was treated with a muscle energy technique and the tender points were treated with counterstrain. She was given a piriformis stretch to perform at home three time daily. She experienced immediate improvement after the treatment. 

This case is typical of piriformis syndrome. An overstretch of the muscle had caused it to con-... 

Internal and external rotation can be tested with the patient seated and the resistance applied to the ankle of the leg being tested. External rotation occurs with contraction of the obturator ex-lernus and internus, piriformis, gluteus maximus, and gemeiii muscles. Internal rotation is provided by the giuteus minimus and tensor fascia iata muscles. 

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